Monthly Archives: March 2017

Introduction to the Special Issue on Type 2 Diabetes Mellitus (T2DM) in Pediatric Patients

Introduction

Type 2 Diabetes Mellitus (T2DM) in children and adolescents is a recent chronic disease facing the medical community in many countries [1-5]. Recent data from the United States (US) has demonstrated an incidence of 8.1 per 100 000 person years in the 10- to 14-year age group and an incidence of 11.8 per 100 000 person years in the 15- to 19-year group. In this survey, the highest rates were found in descending order from American Indian, African American, Asian/Pacific Islander and Hispanic youth, and the lowest incidence occurred in non-Hispanic white youth [1, 3] A recent Canadian survey has demonstrated a similar incidence of T2DM in youth <18 years of age of 1.54 per 100 000 children per year [2-3]. In this survey, 44% of children with new onset T2DM were of Aboriginal origin, 25% Caucasian, 10.1% Asian, 10.1% African/Caribbean and the remaining of other or mixed ethnic origin (2-3). About 45% of new cases of diabetes mellitus (DM) in youth were estimated to be T2DM. The SEARCH for Diabetes in Youth study (SEARCH) has shown that in the US alone in 2010, over 20 000 individuals below 20 years of age had T2DM. Moreover, the survey predicted that this number may increase up to 30 000 by 2020 and up to 84 000 by 2050 [4].

Considering that T2DM in pediatric patients is a relatively new clinical entity, Healthcare professionals (HCP) have had little chance to generate clinical experience in the management of hyperglycaemia and risk factors in pediatric patients with T2DM. Furthermore, very few clinical trials exist to guide clinical practice in T2DM pediatric patients. Therefore, current management guidelines rely largely on data from adult studies and expert consensus [5-6]. However, information regarding adults with T2DM may not always be applicable to youth with the disease.

Also because T2DM in pediatric patients is strongly associated with pediatric obesity current management guidelines rely also on those from pediatric obesity [6-9]. Unfortunately, the literature on the management and treatment for both T2DM and its complications in the pediatric population remains limited. The lack of information about pediatric T2DM may influence the care delivered by HCP. It is hoped that with a well-organised approach in the treatment and prevention that we would be able to stop the onset and progression of this complicated disease. This special issue aims to highlight in a single document what is known about pediatric T2DM and to try to feed most gaps as possible in our understanding of this metabolic disorder.

The review does not address in details all the complications associated with T2DM in this population. Minimal inferences are also made on the metabolic syndrome; a disorder closely associated with T2DM. All the articles mentioned address mostly T2DM. This special issue does not address research about T1DM, except when comparisons with T2DM are required. Similarly, it does not address research about T2DM in adults, but sometimes it is necessary to better document the topics discussed.

In the second article, I will first give you the definition of pediatric T2DM. Then, I will discuss the risk factors and consequences associated with T2DM in pediatric patients. Subsequently, in the third article, I will describe the approaches to prevent T2DM in this age group that are highly comparable to those used to prevent pediatric obesity already discussed in some of my previous publications and books (8-11). The “6As” model for counseling and motivational interviewing methods in primary care clinical practice validated in obese pediatric patients are two effective methods that can certainly be useful to manage T2DM in pediatric patients and has not be discussed yet. Therefore, these methods will be described in details in the fourth article of this special issue on the management of T2DM in pediatric patients. There are only 2 pharmacologic molecules that can be used to treat T2DM in pediatric patients. These 2 molecules will be discussed in the fourth article as well as few other potential molecules that are still not authorized in children for the treatment of T2DM. Therefore, in the subsequent article (article number 5), it seems reasonable to discuss briefly the barriers and potential solutions surrounding the clinical research with pediatric patients suffering from T2DM. The article number 6 is probably the most practical; it is composed of a case report using questions and answers in order to consolidate the information discuss in the previous articles of this special issue. Similarly, pediatric T2DM is difficult to treat, and around 50% of patients treated with Metformin will become less responsive to this drug and this may be due to clinical characteristics of the patients as well as the molecular characteristics of the drug itself used to treat T2DM.That is why I consider useful to introduce in the article number 7 a relatively new concept in this area; this concept is the pharmacogenomics or pharmacogenetics of T2DM with the ultimate goal of having a personalized treatment for those patients i.e., being able to provide a treatment that will be more efficient, more secure and more adapted to a specific patient with T2DM. The fructose metabolism is completely different than the sucrose metabolism and it is associated with a higher risk of obesity and cardiovascular disorders. That is why I decided in the article # 8 to make the point on the issue of fructose to ensure that all the readers are on the same footing regarding this issue. In the article number 9, I discussed the issue of hypoglycemia unawareness. Although this disorder is more frequent in older patients, there is a possibility to get this disorder even in adolescents especially in those that are not highly concerned by their symptoms of diabetes or decide to ignore them, which is frequent in the follow-up of T2DM adolescent patients. Therefore, it seems highly appropriate to already discuss this concept in the context of this document. Finally, I put some energy at finding what should be the best definition of metabolically healthy but obese (MHO) patients as we have observed that many definitions of this concept exist in adults. In this final short review (article # 10), after considering that having diabetes at a young age and for a longer period of time is associated with a very high risk of cardiovascular disorder later in life, I found that the definition of MHO in pediatric patients should be as restrictive as adult patients in order to reduce obesity-associated complication.

For this special issue, I first did a literature search, which searches primarily from January 2006 to December 2016. This research in children and adolescents focuses on the following themes: Pediatric T2DM, primary care, diet, physical activity, sedentary behavior, behavior modification, prevention, T2DM management, fructose, hypoglycemia unawareness, pharmacogenomic and pharmacogenetic. I selected the most recent articles to better reflect current knowledge. Selected documents come from Scopus, Medline and the database of systematic consultation such as Cochrane Reviews.

References

  • Nadeau K and Dabelea D (2008) Epidemiology of type 2 diabetes in children and adolescents Endocr Res 33:35-58.
  • Amed S, Dean HJ and Panagiotopoulos C (2010) Type 2 diabetes, medication-induced diabetes, and monogenic diabetes in Canadian children: a prospective national surveillance study Diabetes Care 33: 786-791.
  • Public Health Agency of Canada (2011) Chapter 5 – Diabetes in children and youth Diabetes in Canada: Facts and figures from a public health perspective.
  • Hamman RF, Bell RA, Diabelea D et al. (2014) For the SEARCH for Diabetes in Youth Study Group. The SEARCH for Diabetes in Youth Study: Rationale, Findings and Future Directions. Diabetes Care. 37:3336-3344.
  • Panagiotopoulos C, Riddell MC and Sellers AC (2013) Canadian Diabetes Association Clinical Practice Guidelines Expert Committee. Type 2 Diabetes in Children and Adolescents.
  • Plourde G, Prud’homme Denis (2012) Managing Obesity in Adults in Primary Care. CMAJ 184:1039-1044.
  • Plourde G (2008) Recommendations on prevention and management of paediatric obesity. Can Fam Physicians 52:322-328,.
  • Plourde G (2014) Paediatric obesity: A guide on diagnosis, prevention and management.
  • Plourde G (2014) Les Jeunes et l’Obésité: Diagnostics et Interventions. Les Presses de l’Université Laval, Editors.
  • Plourde G (2013) Six As Model of Counselling in Obesity. Can Fam Physician 59:353-354.
  • Plourde G, Prud’homme D (2012) The authors respond. CMAJ 184:1603-1604.

Complications Associated with Type 2 Diabetes Mellitus in Pediatric Patients

Introduction

T2DM in pediatric patients is a serious public health problem that requires the attention of stakeholders at different levels. It is associated with immediate health and metabolic problems and it constitutes an important risk factor for early morbidity and mortality. In this second article, I want to define pediatric T2DM and do a small but representative inventory of the causes that could explain its development and discuss briefly its short and long term consequences. In addition, I aim to make uniform these important concepts to ensure that all stakeholders are on an equal step. Obviously, in this special issue, there will be often links made to pediatric obesity as it is the main cause of pediatric T2DM.

Definition

Diabetes mellitus (DM) consist of a heterogeneous group of disorders characterized by intolerance to glucose to eventually develop in hyperglycemia. In clinical practice, Type 1 Diabetes Mellitus (T1DM) contains about 96% of all affected children, and is characterized by an absolute insulin deficiency due to autoimmune destruction of insulin producing β-cells of the pancreas. Unfortunately, affected children will die unless insulin therapy is instituted [1-2].

In contrast, T2DM occurs when insulin secretion is insufficient to meet the increased insulin needs caused by tissue insulin resistance [1-2]. T2DM is frequently associated with obesity, dyslipidaemia, hypertension (HTN), albuminuria, ovarian hyperandrogenism, non-alcoholic fatty liver disease (NAFLD), and obstructive sleep apnoea [1- 2]. T2DM is also associated with component of systemic inflammation as estimated by elevated C-reactive protein, inflammatory cytokines and white blood cell counts [1-2].

As explained earlier, the natural history of pediatric T2DM starts with fasting hyperinsulinaemia, exacerbated by obesity [1-3]. This is followed by postprandial hyperglycaemia, when the pancreatic β-cells are unable to maintain high enough circulating insulin levels to respond to a glucose load as demonstrated by an impaired glucose tolerance (IGT) on an oral glucose tolerance test (OGTT) [3-4]. Due to the combination of both lipid and glucose toxicity on β-cells, increasing tissue insulin resistance and hepatic glucose output, fasting hyperglycaemia follows [1-4] and then T2DM develops.

Genetics of type 2 diabetes mellitus

Several genome wide association studies (GWAS) have been helpful to help highlight the genetic basis of T2DM and several single nucleotide polymorphisms (SNPs) have been discovered to be associated with T2DM. The majority of these SNPs are in non-coding regions or nearby a gene and few are missense mutations (such as the rs1801282 in the PPAR-γ characterized by a C-to-G substitution encoding a proline to alanine substitution at codon 12) [5].

These GWAS studies have demonstrated that the majority of gene variants associated with T2DM are in genes expressed in the β-cells [5]. While the majority of these studies have been conducted in large cohorts of adults, information about these associations in children and adolescent is limited but there is no reason to believe that these observations could be different from those in adults. Dabble et al. genotyped the rs12255372 and rs7903146 variants in or near the TCF7L2 gene in a multiethnic cohort with 1239 (240 cases and 999 controls) children and adolescents enrolled in the SEARCH study; they observed that in African Americans the rs7903146 variant was associated with almost two folds increased odds of T2DM occurrence [6].

Barker et al. genotyped 16 SNPs, found to be associated with diabetes by GWAS studies, in a population of over 6000 children and adolescent, and investigated whether they may be additionally associated with fasting glucose levels [7]. Baker et al. observed that 9 loci were associated with the fasting plasma glucose levels. In particular, they confirmed 5 previously discovered SNPs and discovered 4 more loci associated with fasting plasma glucose. The strongest associations were with the G6PC2 rs560887, MTNR1B rs10830963, and GCK rs4607517, and the effect size of the confirmed loci was similar to that observed in adults. The latter observation confirms that the effect of certain gene variants is constant over time and may not be influenced by changes in insulin secretion and sensitivity occurring with age [7]. Again, the discovery of this SNPs and Loci may represent a great advent for the treatment of T2DM in a sense that children having specific gene may have different glucose level target, different medication and/ or different dosage of the same medication and less risk of developing adverse drug reactions. This interesting topic will be further discussed in the article number 7 of this special issue.

Many studies have demonstrated that the co-occurrence of more risk alleles does not improve the ability to predict the development of T2DM when compared to the clinical risk factors, such as BMI or family history of diabetes and other risk factors [5]. More recently, a significant association between the co-occurrence of risk alleles and T2DM has been observed by the investigators of the CARDIA study [8]. They followed young adults into middle adulthood and observed that the co-occurrence of 38 gene variants predicted the incidence of T2DM over 24 years follow up. In addition, it has been shown that the genetic predisposition to T2DM may be stronger in the pediatric population [8]. In fact, Vassy JL et al. have demonstrated that the co-occurrence of five common variants in or near the genes modulating insulin secretion are associated with a higher risk of developing pre-diabetes and T2DM in children and adolescents. Vassy JL, et al. asked whether the co-occurrence of risk alleles in or near the 5 genes discovered by GWAS studies (TCF7L2 rs7903146, IGF2BP2 rs4402960, CDKAL1 rs7754840, the HHEX rs1111875, and HNF1A rs1169288) might be associated with a higher risk of IGT or T2DM in obese children and adolescents [8]. With a higher number of risk alleles, there is a higher chance of progression from NGT to IGT or T2DM. For those who were IGT at baseline, a higher number of risk alleles were associated with lower odds to revert back to NGT [8].

Despite the strength of these associations, the portion of heritability explained by the identified loci is estimated to be less than 10%. Although the sample size of GWAS studies continues to increase revealing new associations, each newly associated variant has an incrementally smaller effect size to the cumulative variation of the phenotype. GWAS may be reaching the limits of its ability to reveal genetic variations underlying complex traits associated with T2DM [5].

Risk Factors

Risk factors for the development of T2DM in children include the following [9-22]; 1). history of T2DM in a first- or second-degree relative; 2). being a member of a high-risk population (e.g. people of Aboriginal, Hispanic, South Asian, Asian or African descent); 3). obesity; 4). IGT; 5). PCOS; 6). exposure to diabetes in utero; 7). acanthosis nigricans; 8). HTN and dyslipidemia; 9). NAFLD; 10). atypical antipsychotic medications and 11). neuropsychiatric disorders. In the following paragraphs I will only discussed some of these risks factors. However, while you perform the medical history of a new pediatric patient with T2DM all of the above should be considered.

Family factors

An important risk factor in the increase risk of developing T2DM in youth is the genetic influence [23] as discussed above. A strong family history of diabetes is present in 45% to 80% of children with T2DM. Having parents with T2DM is a risk factor for the development of T2DM among pre-pubertal youth. Children born to mothers with T2DM are particularly at increased risk for T2DM when compared to children and adolescents whose fathers had T2DM. The risk is higher for boys than for girls for a ratio of 2 for 1. More females than males are diagnosed with T2DM during puberty; however, among adults, more males than females are diagnosed with T2DM according to the data from the Public Health Agency of Canada [23].

Insulin resistance

Insulin resistance associated with T2DM means an impaired response to the physiological actions of insulin on glucose, lipid and protein metabolism and on endothelial function [1-3]. The main tissues affected by insulin resistance are the liver, muscle and fat. In the liver this impaired insulin-related action leads to an increased hepatic glucose output which exacerbates hyperglycaemia. In muscle, insulin resistance leads to reduced transport of glucose into muscle combined with lipid deposition in muscle cells which results in impaired exercise ability and reduced the threshold for fatigue in response to physical activity. In fat tissue, there is impaired insulin mediated reduction of hormone-dependent lipase, with breakdown of lipids to free fatty acids and glycerol, contributing to dyslipidaemia [1-3].

Insulin resistance is a key factor in the development of T2DM in both adults and pediatric patients [1-3]. While insulin resistance is most commonly associated with obesity, it is not all obese children that have insulin resistance and conversely insulin resistance is seen also in non-obese children. As briefly discussed above, several genes linked to beta cell function and insulin sensitivity have been demonstrated to be associated with T2DM in different population. For Instance, the T2DM protective variant Pro12Ala in PPAR-ϒ is associated with higher insulin sensitivity in Caucasian children [5] which suggest that this variant can be considered as a possible molecule for the treatment of T2DM in pediatric patients (See article # 7).

Overweight and Obesity

Obesity is the major contributor to the rising prevalence of T2DM in children [1-3]. Globally, overweight and obesity are extremely common in T2DM, affecting about 90% of children and adolescent and 92% have two or more cardiovascular (CVD) risk factors at the time of diagnosis of T2DM [24]. For instance, HTN affects approximately 23% of children and adolescent with T2DM and lipid abnormalities about 33% of them. Clearly, youth who are overweight or obese have a higher risk for early T2DM development. Weight loss and/or weight maintenance is effective in preventing T2DM in at-risk children and adolescent. As expected, youth with T2DM tend to be less active, less physically fit, and more sedentary when compared with aged matched non-diabetic children and adolescent which emphasis our role in putting in place public health measures to keep our youth active. Risk prediction models estimated that by 2035, up to 100,000 excess cases of CVD could be attributable to increased obesity in children and adolescent. This is likely to get worst by the earlier age of onset of T2DM [24]. In Canada, currently almost 1 in 7 children and youth are obese. Rates vary based on sociodemographic factors such as age, sex, socioeconomic status and place of residence. But the good news is that overall; the rates of excess weight have been relatively stable over the past decade [25].

T2DM is associated with a twofold excess risk for a wide range of CVD, including coronary heart disease, stroke, and vascular deaths, after adjusting for age, sex, smoking status, BMI, and systolic blood pressure [24]. The causes for this increased risk for CVD complications and mortality in T2DM compared with T1DM are not well understood. Certainly, obesity and a greater degree of insulin resistance in obese youth with T2DM compared with obese peers with normoglycemia and compared with youth with T1DM may be the underlying factors for this higher CVD risk, with an added effect related to chronic exposure to hyperglycemia. According to Bacha F and Gidding SS, hyperglycemia and insulin resistance are associated with increased oxidative stress and increased advanced glycation end-products, which have been implicated in microvascular and macrovascular complications [24].

Puberty

Puberty is a period of dynamic physiologic change, including activation of the reproductive axis and subsequent secretion of sex steroids hormones, acceleration in growth, and accumulation of both lean and fat mass. There is also a well-known physiologic decrease in insulin sensitivity during puberty. The presence of relative insulin resistance in puberty was first described by Amiel et al. in 1986 in a study designed to explore reasons for deterioration of glycemic control in pubertal children with T1DM (26). The authors found that pubertal children, both with and without diabetes, had lower insulin sensitivity than prepubertal children and adults [26]. This transient pubertal reduction in insulin sensitivity has been confirmed in multiple cross-sectional and longitudinal studies [26-27].

Puberty is also a period of change in other cardiometabolic risk factors, such as lipids, blood pressure, and adipokines. This has significant implications for obese children and adolescents. In fact, there is evidence that puberty is one of the greatest risk factors for transition from metabolically healthy to unhealthy obesity [28]. Furthermore, the incidence of youth-onset T2DM is tightly linked with puberty as mentioned before. For these reasons, it is critical to understand the normal physiology of metabolic changes during puberty and the additional impact of obesity on these changes. In healthy youth, this decline in insulin sensitivity discussed above is accompanied by compensatory insulin secretion that recovers after puberty is completed. In contrary, there is evidence that obese youth do not recover baseline insulin sensitivity at the end of puberty [27].

Antipsychotic Medications

Children and adolescent receiving treatment with antipsychotic medication are particularly susceptible to weight gain, T2DM and its associated metabolic disorders [29]. The risk of T2DM is 2 to 3 fold that of the general population, it starts early in the course of treatment, and reflects the effects of weight gain in conjunction with the direct effects of antipsychotics on the hypothalamus, the pancreatic β-cells and the insulin-sensitive peripheral tissues. Regular monitoring with early intervention through lifestyle intervention is essential with the use of this medication, Switching for antipsychotics with less deleterious metabolic effects and adjunctive treatment with metformin are modalities available to mitigate weight gain and improve cardiometabolic health in these patients [29].

Comorbidities

Short-term complications in pediatric patients with T2DM include diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar state (HHS). Around 10% of Canadian children and adolescent with T2DM present DKA at the time of diagnosis of T2DM (23, 30-31). Up to 37 % of mortality rates have been reported in youth presenting with combined DKA and HHS at the onset of T2DM. Evidence suggests that early-onset of T2DM is often associated with severe and early-onset of microvascular complications, including retinopathy, neuropathy and nephropathy [23, 30-31]. Micro- or macroalbuminuria has been observed frequently in children and adolescent at the time of diagnosis of T2DM [23, 30-31]. For the purpose of this article, it is impossible to discuss all the co-morbidities associated with T2DM in details. Therefore, my discussion will be limited to the most common one.

Cardiovascular complications

One reason for the possible future of CVD is that the high density lipoprotein (HDL) size shifts to smaller particles in children and adolescent with T2DM [24, 31]. A major cause to explain this shift is the insulin resistance. The changes that occur in T2DM patients are influenced by the changes observed in obesity. For example, carotid intima-media thickness (CIMT) has been noted to be thicker and stiffer among obese adolescents with T2DM than among non-obese adolescents without T2DM [32]. Regardless of the causative factor, these vascular changes can predispose obese adolescents with T2DM to stroke and myocardial infarction later in life [32].

Unfortunately, many of the lifestyle behaviors associated with these risk factors in adults, such as physical inactivity (sedentary lifestyle), poor eating habits, smoking and others, origin in childhood and adolescence, and the risk factors for both CVD and T2DM that can be tracked from childhood into adulthood increase the likelihood of adverse health outcomes in adulthood [33]. Therefore, it is evident that early screening for these risk factors in children and adolescents and early interventions to address these unhealthy lifestyle behaviors will help prevent the development of these diseases in later years [33]. Given the unfortunate rise in both of these diseases in pediatric populations, it is increasingly important to begin prevention efforts in childhood or even prenatally (this will be further discussed in the following article of the current issue).

Vascular Health in Children and Adolescent with Obesity and T2DM

Results from autopsy studies of individuals dying from non-cardiac causes demonstrated a strong association between obesity and the extent and severity of early coronary atherosclerosis in adolescents and young men [32]. In large population-based cohort studies, a strong linear association was found between BMI in childhood and adolescent and risk for coronary artery disease (CAD) in adulthood [24, 32]. These studies clearly indicated a clear relationship between obesity in the childhood years and subsequent CVD in adulthood [24, 32-33]. This has led to an effort to better understand the pathophysiology of vascular injury in children and adolescent using surrogate measures of subclinical vascular disease to help in risk prediction. These methods include the peripheral endothelial function measures (PEFM), the brachial artery reactivity measurement (BARM), the carotid intima-media thickness (CIMT), aortic pulse wave velocity (a-PWV), and peripheral arterial tonometry (PAT) measurements among others. PWV is a marker of arterial stiffness and is associated with CVD and predictive CV mortality in adults. CIMT is a marker of atherosclerosis and is predictive of CV morbidity and mortality in adults.

Using these methods, it was found that the BARM was adversely affected by overweight/obesity and hyperinsulinemia in children suggesting that these patients has less brachial artery distensibility compared to normal subjects [24]. Children and adolescent with T2DM and with obesity were found to have elevated a-PWV compared with normal weight controls suggesting a higher risk for arterial stiffness in this population. Youth with T2DM had higher CIMT compared with lean and obese normoglycemic controls indicating a higher risk for atherosclerosis. Finally, an association was found between CIMT and glycemia, as reflected by the HbA1c, whereas vascular stiffness measure by the a-PWV was mainly related to insulin resistance and inflammation.

These findings suggest that different aspects of the vasculature are differentially affected by different metabolic disturbances associated with childhood obesity and T2DM. These findings also demonstrate that the presence of early coronary artery calcification in these obese youth. These calcifications were mainly related to total body fat and abdominal adiposity measures independent of the traditional CVD risk factors of blood pressure and dyslipidemia [24]. Globally, these studies of surrogate markers of vascular health indicate premature aging of the vascular system in children with obesity and T2DM and a higher propensity for early-onset CVD events in young adulthood.

Retinopathy and nephropathy

In addition to macrovascular changes, T2DM can also present with major microvascular induced complications such as retinopathy, microalbuminuria, neuropathy and nephropathy [34-35]. According to the authors, one of the reasons for the increase in diabetic microvascular complications among adolescents with T2DM is due to the increased in blood hypercoagulability secondary to an elevation in D-dimer and in the total serum cholesterol levels [34-35].

However, even though retinal abnormalities i.e., retinal venular dilation occur very early in the course of T2DM, the clinical picture may remain occult during childhood and adolescence. For example, most diabetic retinopathy during childhood and adolescence remains only as background retinopathy. Therefore, glycemic control during childhood and adolescence is essential in order to delay or to prevent the development of diabetic retinopathy later in life [34-35].

Non-Alcoholic Fatty Liver Disease (NAFLD)

The deposition of fat in the liver is commonly associated with T2DM, with approximately 25% of children having NAFLD at the time of diagnosis of T2DM [5]. NAFLD is determined by an elevated serum liver enzyme levels because of infiltration and accumulation of large triglyceride droplets within the hepatocytes [5]. Adolescents with T2DM have nearly three times as much hepatic triglyceride as adolescents of a comparable weight but without T2DM (36-37). As a consequence of this elevated tryglyceride levels, NAFLD occurs and it is the most common cause of childhood liver disease and is common in pediatric patients with T2DM, dyslipidemia, and abdominal obesity. Approximately 3% to 10% of children in the general population and 40% to 70% of obese children have NAFLD [5].

Recent studies in obese children and adolescents have demonstrated the effect of hepatic steatosis on insulin sensitivity. In a multiethnic group of 118 obese adolescents, it was observed that independent of obesity, that the severity of fatty liver disease was associated with the presence of pre-diabetes i.e., IGT with and without IFG [36]. In parallel to the severity of hepatic steatosis, there was a significant decrease in insulin sensitivity and impairment in beta-cell function in these obese adolescents. Moreover, it was observed with the increasing severity of fatty liver disease, that there was a significant rise in the prevalence of the metabolic syndrome, suggesting that hepatic steatosis may be a strong predictive factor of metabolic syndrome in obese children and adolescents [36].

In recent studies, the role of hepatic fat content in modulating insulin sensitivity was shown [37-39). The authors studied two groups of adolescents, one group with hepatic steatosis and the other group without this disorder. The two groups had similar visceral fat and intramyocellular lipid (IMCL) contents [37]. The obese subjects with hepatic steatosis showed an increased in muscular and hepatic insulin resistance; although not statistically significant, and a trend towards increased adipose tissue insulin resistance was also noted [37]. In a recent longitudinal study it was shown that the baseline hepatic fat content correlates with the 2-hour glucose, insulin sensitivity, and the insulin secretion at follow-up. These data indicate that the deleterious effect of intra-hepatic fat accumulation influences the insulin sensitivity at a multi-organ level, playing a bigger role than the other ectopic compartments [38].

Hepatic steatosis is only the first step of a more complex disease known as NAFLD, which has become the most common cause of liver disease in obese pediatrics patients [38-39]. NAFLD is defined by the presence of macrovescicular steatosis in more than 5% of the hepatocytes in the absence of drug consumption, alcohol abuse and other determinants that may result in fatty liver (38-39). NAFLD encompasses a range of disease severity, from simple steatosis to non-alcoholic steatohepatitis (NASH) and cirrhosis [39].

Therefore, the screening for NAFLD should be recommended to overweight and obese children (40) and also in children and adolescents with T2DM. Although liver histology is the gold standard for diagnosing NAFLD, performing biopsies in regular clinical practice to determine disease prevalence is not always possible. Children with NAFLD typically have elevated liver enzyme values [aspartate aminotransferase (AST), and alanine aminotransferase (ALT)] in absence of other causes of steatosis. Therefore, elevated serum levels of liver enzymes, even though they often misrepresent the entity of intrahepatic damage, are used as a non-invasive test to screen for pediatric NAFLD along with liver ultrasound (US), that can detect the disease when steatosis involves >30% of hepatocytes. Although it does not represent the imaging gold standard, performing liver US has several advantages as a screening tool including it’s: 1) relative low cost; 2) large diffusion in medical community, and 3) feasibility in the pediatric population (41). However, a diagnosis based upon elevated liver enzymes is not necessarily sufficient to diagnose NAFLD. If ALT levels are elevated three times the upper limit of normal for more than six months, an abdominal examination using liver US should be performed to rule out the possibility of viral hepatitis. Liver biopsy is required for accurate diagnosis and staging of the NAFLD [40].

Computed tomography (CT) scan is not recommended in pediatric setting to screen for NAFLD because of the unjustified radiation exposure involved in the process (41). Magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) have been demonstrated to be the best methods to assess and quantify the amount of lipids present in the liver, but these techniques are too expensive to be used in clinical practice [38].

NAFLD, as well as reduced insulin sensitivity, may be reversible by application of even a short-term diet and exercise program that induces weight loss [3]. If left untreated, however, NAFLD is progressive and may ultimately lead to cirrhosis later in either childhood or adulthood. Other complications associated with NAFLD include a possible progression to hepatocarcinoma, liver-related death in adulthood, and the development of CVD.

Dyslipidemia

Pediatric patients with T2DM have an increased prevalence of dyslipidemia, with ~ 45% of children reported to have dyslipidemia at the time of diagnosis. There is recommended to, screen for dyslipidemia at diagnosis of T2DM and every 1 to 3 years as clinically indicated thereafter [30].

In pediatric patients, dyslipidemia is significantly worse among those with T2DM when compared to those who are obese but without T2DM. Even with tight glycemic control, the dyslipidemia may persist [31-32]. Nevertheless, data on dyslipidemia in pediatric patients with T2DM remain limited. The problem is complicated by the differences among ethnic groups. For example, Canadian Aboriginal children with T2DM were less likely to present with dyslipidemia than White children with T2DM [23, 30]. The control of elevated triglycerides is important in preventing the development of CVD as dyslipidemia including elevated levels of triglycerides are also risk factors for the development of CVD and atherosclerosis in patients with T2DM [23, 30, 43-44].

These risk factors are highly prevalent in children and adolescents with T2DM early in the presentation of the disease. Moreover, youth with T2DM appear to be at higher risk for these complications when compared with children and adolescents with T1DM. In the SEARCH for Diabetes in Youth study, youth with T2DM exhibited a more atherogenic lipid profile compared with youth with T1DM, with higher fasting total cholesterol, higher LDL-C, and triglycerides and lower HDL-C, for a similar degree of HbA1c elevation [45].

The first step in the treatment of dyslipidemia should be weight loss through diet and exercise, as both of which are known to have a significant impact on cholesterol levels (discussed in article number 4). If the use of drug is not needed or if other options are available they should first be used. If the cholesterol levels continue to increase with age and if other signs of CVD are discovered perhaps statins would be something that needs to be considered. However, statin is not approved to be used in children and it’s not worth risking the side effects associated with statins when long term effects are unknown. Statins should only be use if the benefits outweigh the risks and there are no alternatives [30].

In children with familial dyslipidemia and a positive family history of early CVD events, a statin should be started if the LDL-C level remains >4.1 mmol/L after a 3- to 6 months of unsuccessful life style interventions (LSI). The goals of the therapy are to maintain LDL-C below 2.6 mmol/L, triglycerides below 1.7 mmol/L, and HDL-C above 0.9 mmol/L. Statins are the first line of therapy in these patients. However, long term effects have not yet been determined and they are known for have mild side effect of headache, GI distress, and myalgia [42-43].

Hypertension (HTN)

HTN (BP ≥ 95th percentile for age, sex, and height and confirmed on two visits is present in 20–30% at initial diagnosis of T2DM. Blood Pressure (BP) should be checked at diagnosis and with every clinical visit afterwards [30]. When HTN is associated with proteinuria, it can progress to end-stage renal disease (ESRD) and requires aggressive treatment [46]. HTN may be responsible for 35–75% of micro- and macrovascular problems in T2DM. HTN is uncommon in the general pediatric population. However, HTN is more common among children with T2DM than children with T1DM. Among children with T2DM, rates for HTN range from 12% to 36% [46].

As for dyslipidemia, the development of HTN also varies according to ethnicity and the family history of HTN. Minimal weight loss and LSI is most of the time sufficient to correct HTN in obese pediatric patients with T2DM. However, if the HTN is not corrected after 3–6 months of LSI, treatment using angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) might be considered (Further detail will be provided in the article number 4).

Pancreatic complications

β-cells function in overweight and obese adolescents is impaired relative to the reduction in insulin sensitivity in pediatric patients with T2DM [46]. This is due to the fact that β-cell function is rapidly declining, even without significant changes occurring concurrently, with peripheral or hepatic insulin sensitivity. At the time of diagnosis of T2DM, adolescents already present with β-cell dysfunction that is comparable to that observed in their adult counterparts. In response to β-cell dysfunction, it is recommended to use the HbA1c as a screening tool to investigate the progression and even the reversal of T2DM risk in such adolescents [47].

Polycystic Ovary Syndrome (PCOS)

PCOS is seen in obese and T2DM women, including adolescents [48-50]. The diagnosis criteria are not fully defined in teens because several features of PCOS are only seen during the course of normal puberty. However, emphasis on using more rigorous criteria for teen PCOS diagnosis has gained more support, including the recently revised Rotterdam criteria; these involve having oligo- or anovulation or primary amenorrhea at 16 years of age, clinical and biochemical hyperandrogenism, and ovarian volume of ≥ 10 cm3 on ultrasound (need 3 of 3) [51]. Patients with PCOS require an OGTT as there is a higher rate of dysglycemia associated with the diagnosis of PCOS. Some of the features of PCOS result from excess insulin actions including increasing ovarian testosterone production and reducing hepatic sex hormone-binding globulin production [51].

The treatment of PCOS involves LSI; in addition, combined oral contraceptive pills, antiandrogens (e.g., spironolactone), and insulin sensitizers including metformin all play a role in different patients [47]. For more information on the management of PCOS in pediatric obese patients, please consult the book of Dr. Plourde on the management of pediatric obesity, especially on chapter 7 of this book and in the learning module for the BMJ [49-50].

Proteinuria

Microalbuminuria (≥2.5 mg/mmol) or macroalbuminuria is far more common in T2DM when compared to T1DM. Microalbuminuria was present in 22.2% of T2DM versus 9.2% in T1DM patients [34-35, 46, 52]. It was observed in Canada that 14.2% of T2DM subjects had proteinuria (30). The rate of progression of microalbuminuria is also faster in T2DM. Screening for proteinuria should start at diagnosis and annually afterwards. It should be confirmed on 2-3 samples [30].

Screening can be done initially with a random or early morning albumin: creatinine ratio (ACR), and, if the result is abnormal, this should be confirmed with another early morning ACR 4 weeks later. If the two results are abnormal, a timed overnight urine collection for ACR should be done. The diagnosis is made by repeated samples over 3-4 months, and, if persistent over 6–12 months, then a referral to nephrology specialist for further evaluation is warranted. A patient with T2DM should be tested several times a year for protein in the urine [30, 52].

This is a sign that there is diabetes related kidney damage as the kidney is allowing protein to escape the body without being absorbed. An extremely high amount of protein may be a sign of kidney disease [34, 52]. Kidney malfunctions and diabetes are related as kidneys are one of the organs that respond to the body’s glucose intolerance [34, 52].

Renal injury

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) can begin in childhood, particularly in children who are obese and have T2DM (35). In fact, diabetic kidney disease (DKD) remains a leading cause of morbidity and mortality in people with T2DM. The 2011 US Renal Data System reported that DKD accounted for 44.5 % of all cases of ESRD. In 2009, overall Medicare expenditure for people with CKD and diabetes accounted for $18 billion [53]. The prevalence of DKD has remained relatively stable over the last 20 years, despite increasing prevalence of T2DM, likely related to improved glycemic control, blood pressure, and weight control, since evidence-based therapies directly targeting DKD are rather rare. However, children and adolescents with T2DM are at higher risk for developing primary renal disease (e.g., IgA nephropathy, membrano-proliferative glomerulonephritis) and a four-fold increased risk for developing renal failure. As such, children and adolescent diagnosed with T2DM should be screened with regards to glomerular filtration rate (GFR), blood pressure, and urinary albumin excretion rate [30, 52, 54-55]. The detection of microalbuminuria is the earliest possible marker for renal disease; it is also an independent predictor for future CVD morbidity and mortality [35, 52, 54-55]. However, renal disease cannot be reliably determined only by clinical and laboratory findings. Renal biopsy is needed to provide accurate diagnosis of renal disease. T2DM and HTN are the 2 leading causes of ESRD. The risks for developing diabetic nephropathy are further increased by the presence of the co-existing risk factors of hyperlipidemia and/or obesity [34]. The risk factors for DKD in T2DM include female sex, obesity, triglycerides, hyperglycemia, CVD, insulin resistance, and elevated uric acid (39). Children and adolescent with T2DM have increased risk for earlier onset and accelerated progression of albuminuria when compared with both their T1DM counterparts and adults with T2DM of similar duration [54-55]. Furthermore, children and adolescent with T2DM have an extended lifetime exposure to these risk factors [34].

As discussed earlier, β-cell failure may have a negative impact on nephropathy progression [26-27, 34]. In addition, worsening of glycemic control among teens and young adults with T2DM is responsible for both earlier and increased cumulative microvascular complications [54-55]. Longitudinal data from the T2DM in Adolescents and Youth (TODAY) study predict that children and adolescents diagnosed with T2DM may have a much more aggressive course of disease with an increased risk for early HTN and nephropathy when compared with adolescents with T1DM. [56] A higher prevalence of hyperlipidemia, NAFLD, and inflammatory markers further contributes to the concern for cumulative lifetime nephropathy risk in children and adolescents with T2DM [57-61].

Sustained motivation of youth with T2DM to adhere to LSI is often difficult. Also, the compliance with medical therapy and LSI recommendations is often hampered by a multitude of contributing psychosocial, medical, and physiologic factors [49-50]. Effectively addressing the underlying factors that contribute to deteriorating glycemic control, HTN, and obesity in adolescent is critical to reducing renovascular disease risk in T2DM pediatric patients [5]. This very important issue will be discussed in depth in the article number 4. In the previous book and learning module from Dr Plourde, the use of motivational interviewing clearly explain how to proceed to help manage the issue of non-compliance and lack of motivation in pediatric patients having chronic diseases such as obesity [49-50].

Conclusion

To date, a huge number of complications have been identified regarding T2DM in children and adolescents including cardiovascular (coronary heart disease, macrovascular and microvascular changes, HTN), metabolic (dyslipidemia), hepatic (NAFLD), pancreatic (â– cell dysfunction), pulmonary (altered peak oxygen intake, sleep disorders), and renal (CKD, ESRD). Considering, the high number of complications associated with T2DM, it is, therefore, essential that major effort be put in place at the prevention level to ensure that this number will not further increase. Efforts should also be put in place to rapidly diagnose and treat these patients. Which further increase the need of rending available to the HCP, and to other stakeholders relevant information on the prevention and on the management of T2DM in pediatric patients?

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Prevention of T2DM in Pediatric Population

Introduction

The large numbers of children and adolescent with obesity suggests that we have the potential for greater numbers of youth developing T2DM in the near future. Prevention of T2DM in the pediatric population requires prevention of obesity, particularly in at risk groups such as children and adolescent from ethnic minorities, children and adolescent with a family history of T2DM and others as discussed in the previous article. Prevention of T2DM involves reversing inadequate eating and sedentary habits in homes, schools and communities that lead to excess calorie intake and decreased energy expenditure. Chapter 2 of the book from Dr Plourde as well as his learning module provide very useful information on the prevention of pediatric obesity that can also be applied to pediatric patients with T2DM [1-2].

As explained in these documents, most lifestyle interventions (LSI) to prevent pediatric T2DM at the individual or family level should target changes in dietary and physical activity habits [1-3]. In a recent study the participants were able to reverse obesity-related markers of inflammation after 3 months of participation in LSI despite negligible changes in body weight (4). There were significant decreases in body fat mass and insulin resistance confirming that LSI approaches are very useful tools to prevent T2DM in pediatric patients [1-4].

A multicomponent family-based randomised controlled trial (RCT) with severely obese children has shown improvements in cardiometabolic factors that persisted into follow-up even though differences in weight between the intervention group and the usual care participants did not persist [5]. In this RCT, LSI has focused more exclusively on manipulating the macronutrient composition of the diet without the inclusion of an exercise component [6]. Again this study confirm that LSI is very helpful at preventing T2DM and supports the concepts discuss in the book and articles by Plourde that involving the family in the treatment of obese children and adolescent further increases the chance for success [1-3]. In a study conducted in obese adolescents, it was found that a low glycemic index diet through home provision of water and diet beverages to displace consumption of sugar-sweetened beverages (SSBs) was superior to a more traditional low-fat diet for weight loss and improving insulin resistance [7] which goes in the sense of the recommendation of no added sugar and no SSBs to promote weight loss in overweight or obese youth [1-3]. There is no doubt that this recommendation is also applicable to T2DM pediatric patients since the majority of them are overweight or obese.

The PREMA study (Prediction of Metabolic Syndrome in Adolescence) has identified other risk factors that could be associated with a higher risk of developing T2DM in youth that are important to consider in the medical history of a pediatric patient presenting with T2DM. These risk factors include low birth weight, small head circumference, and parental history of overweight and obesity [8]. Therefore, prenatal interventions with prospective parents may be useful to reduce future risk of T2DM in children and adolescent. Unfortunately, it may be difficult to create changes at the individual level since our current environment or societal influence is so unfavorable. Even with targeted early prevention programs, overcoming these larger societal issues is difficult [9].

As stated earlier, before the development of T2DM in youth, at-risk children and adolescent progress through a period of IGT due to insulin resistance accompanied by β-cells dysfunction [10-11]. Establishing adequate lifestyle routines and decreasing sedentary behaviours time before puberty may be especially important to help prevent T2DM, given that T2DM in youth generally develops during the adolescent years and especially at the time of mid-puberty as explained earlier.

Furthermore, physical inactivity has an additive impact upon the patient who may already show signs of insulin resistance before puberty [12-14]. In the other hand, increased isometric muscle strength and cardiorespiratory fitness in children and adolescent with insulin resistance and β-cells dysfunction has been associated with reductions in fasting insulin level, HOMA-IR and HOMA-B in young adulthood [15]. Considering that the prevention and even the reversal of inadequate glycemic control is possible with LSI [16-17] it is essential that our public health efforts should be oriented on the prevention of T2DM throughout LSI. To be successful in this prevention effort, we need the collaboration of the entire community. In the following sections of this article, I am presenting the role of various groups in the prevention of T2DM and its associated complications. Since the prevention of T2DM in this population is tightly linked to the prevention of pediatric obesity in the following paragraphs I also include pediatric obesity in the discussion.

Parents

While it is apparent that the involvement and support of parents in behavior change programs is critical for the success in the prevention and treatment of children and adolescent at risk for T2DM and CVD, the long-term impact of family-based LSI efforts toward prevention of risk factors for T2DM and eventually CVD deserves our attention [18]. Some experts in the obesity field would argue that efforts to prevent the devastating health effects of obesity should begin in early childhood and it is the same with T2DM in pediatric patients. As for the treatment of pediatric obesity, children are not the only individuals targeted by LSI since parental weight loss has been shown to predict weight loss in overweight children when parents have been encouraged to lose weight along with their children. In fact, it was found that for every 1 BMI unit reductions in parents, their children experienced a 0.255 reduction in BMI units [19]. Therefore, encouraging weight loss in parents who are overweight should be included in any family- or home-based obesity prevention program for children. Since pediatric obesity is highly linked to pediatric T2DM, this approach is suitable for the latter.

Improving the health of prospective parents may be an important focus in T2DM prevention efforts. Family-based interventions are important, as the analysis of the community-based pediatric obesity prevention program, “Be Active Eat Well,” (http://www.healthinfonet.ecu.edu.au/key-resources/programs-projects?pid=50) suggests [20]. This analysis demonstrates that the home environment has more influence on zBMI than the school environment, but other studies have shown that community-based programs to prevent obesity in children benefit from the inclusion of dietary and physical activity components that are implemented within the schools as well [21-22].

Peer and Social Support

As adolescents with T2DM often report feeling isolated from peers, marginalized and that support for behaviour change is essential in changing lifestyle, we can argue that peer-led approaches may be necessary for behaviour change in children and especially adolescent with T2DM. It was found that young children receiving curriculum that supported healthy living behaviours from older peers experienced significantly greater reductions in measures of adiposity and noted improvements in healthy living knowledge. Children and adolescent living with and at risk for T2DM often require programmes more relevant to their immediate needs and often their immediate needs is to be accepted by the groups, not being isolated from peers and other primary needs even more immediate than losing weight [1-3].

School-/Community-Based Interventions

A multicomponent lifestyle intervention delivered to inner city was also tested in a minority of children and adolescent at risk for T2DM within the school [23]. In this study the authors investigated the addition of coping skills training (CST) and health coaching to see if these would improve outcomes by addressing participants’ barriers to incorporating lifestyle changes. Schools were randomized to either the CST intervention (four schools) or the general education (GE) intervention (two schools). All seventh graders in the schools received the same nutrition and activity educational component (eight classes), but the CST schools received an additional five classes in CST and the youth identified as at-risk for T2DM received 9 months of telephone health coaching. Interestingly, the participants from the schools randomized to the CST intervention evidenced improvements in some key markers of metabolic risk such as decreased BMI of T2DM patients at the end of the intervention. Recent reviews suggest that school-based obesity prevention interventions can be effective in reducing BMI among children [24-25], particularly for those programs with more comprehensive content, involving parental support, and duration longer than 1 year. It was concluded that there is strong evidence that school-based studies of physical activity, that include a home component, improve obesity outcomes [26] and even though not studied in children and adolescent with T2DM indirectly we can conclude that these approach would have a similar impact. Two of the three studies reviewed by Wang et al [27] focused on reducing sedentary activity, which may have contributed to the positive results. In addition, combined interventions of diet and physical activity interventions in schools that included home and community involvement should be more effective [1-3].

Public Health Initiatives and Interventions

Savoye and colleagues [16] evaluated the effects of the Bright Bodies (BB) Healthy Lifestyle Program (http://www.brightbodies.org/program.html) on 2-h OGTT results in comparison with adolescents receiving standard of care. The intervention group attended exercise and nutrition/behavior modification classes over the course of 6 months. The BB program significantly decreased 2-h glucose in children at high risk for T2DM after 6 months. In addition, the intervention group lowered BMI z scores by maintaining weight close to baseline values, while the control group continued to gain weight. The BB group also had greater improvements in systolic blood pressure, fasting triglycerides, reduced total body fat, improvements in insulin sensitivity, and statistically and clinically significant improvements in glucose tolerance.

Several public health initiatives have been created at the national and international levels in an effort to reduce children’s CVD risk factors [28]. The World Heart Federation has created a program for children and adolescent called the Youth for Health (Y4H) campaign (http://hriday-shan.org/?page_id=439) in which children and adolescent are encouraged to mentor and educate their peers on the importance of preventing CVD risk factors in their lives. The American Heart Association, the Clinton Foundation and the Alliance for a Healthier Generation work across several sociocultural levels, families, schools, corporations, and HCPs, to prevent childhood overweight and obesity which indirectly would have an impact on the prevention of T2DM in pediatric patients (https://www.healthiergeneration.org/). The First Lady’s signature program, “Let’s Move!,” seeks to improve children’s health and decrease CVD risk factors by increasing children’s physical activity, improving the nutritional quality of their school lunches, and increasing families’ access to healthy food and activity (http://www.letsmove.gov/) which would also have an impact on the prevention of T2DM in pediatric patients.

The Creating Opportunities for Personal Empowerment (COPE) (https://www.cope2thriveonline.com/) intervention provides promising evidence that the inclusion of educational materials that promote self-efficacy, problem solving, stress management, coping and communication can positively influence both mental and biological health outcomes in overweight adolescents. Compared to standard intervention that promoted simple healthy living messages, the COPE-enhanced programme led to significant short and long-term reductions in adiposity, improvement in social skills and lower substance use in overweight adolescents. Among children and adolescents, the promotion of structured physical activity, particularly within schools, is an effective approach for reducing depression. The effects were particularly robust among adolescents older than 13 years and those that are overweight or obese. Although no data are published for children and adolescent with T2DM, there is no doubt that such program is also beneficial for them.

The Centers for Disease Control and Prevention’s Steps program (also known as the Steps to a Healthier US program) (http://www.cdc.gov/nccdphp/dch/programs/healthycommunitiesprogram/evaluation-innovation/pdf/stepsinaction.pdf) is another initiative targeting the prevention of chronic diseases such as T2DM and CVD in children and adolescent [29]. The biomedical results from a state-level study, the Carolina Abecedarian Project (ABC), have recently been analyzed. This early intervention initiative targeted disadvantaged children and adolescent between ages 0 and 5 years resulted in significantly lower prevalence of risk factors for CVD and metabolic diseases when the participants were assessed in their mid- 30s [29]. This is an example of initiative that can be used by other states or other countries with the chances of resulting on positive preventive impact on their at risk population.

The ABC project has demonstrated the persistence of early intervention benefits into adulthood, and more such longitudinal studies are needed to determine whether lifestyle-induced changes targeting cardiometabolic risk factors in childhood persist over the long term [29]. Although LSI aimed at reducing the risk of T2DM and CVD have traditionally focused on dietary and physical activity behaviors, there is strong evidence identifying other modifiable risk behaviors that should be included as targets in LSI to prevent non communicable diseases such as T2DM and CVD.

Smoking, sleep, and mental health such as depression are a few examples of the concerns that warrant attention in the design of future risk reduction efforts. While smoking has long been associated with CVD risk, it has been implicated as a risk factor for T2DM as well [30- 31]. Smoking initiated at an early age (age 16) has been found to be associated with increased risk for T2DM in men [32]. Therefore, CVD and T2DM prevention efforts with children and adolescent would benefit from including smoking cessation treatment components in their LSI efforts [33-34]. There is evidence in adults that there is a relationship between sleep duration and T2DM risk since both long and short sleep durations have been found to be associated with increased risk for T2DM [35-37]. Additional research into the role of sleep disturbance and risk for T2DM and CVD in children and adolescent is warranted since Matthews et al. [38] found a relationship between short sleep duration and insulin resistance in youth but not for long sleep duration.

Social Networks and Social Media

Social media is largely present in the lives of adolescents and significantly influence their behaviour. The American Heart Association recently released a statement regarding the efficacy of social networks in the prevention and management of childhood obesity [39] and indirectly T2DM. There is significant evidence that behaviours related to weight are associated with individuals within social networks, in some cases in a dose-response manner [40-41]. As overweight and obese children and adolescent are more likely to be socially isolated [42], the use of social media may be an attractive approach to support behaviour modification, particularly using a peer-based approach [40-44].

Systematic reviews of web-based approaches to behaviour modification in children and adolescent revealed mixed results [45]. In most cases, internet-based approaches lead to changes in lifestyle behaviours and in some cases reductions in adiposity. The effects of the interventions are often modest; however, these approaches are often used in clinical practice with very good succes. Future studies aimed at behaviour modification for lifestyle management in youth with T2DM may want to consider these approaches.

For the Health Care Providers and Policy Makers

The ADA (in 2000) and ISPAD (in 2011) have formulated recommendations for screening asymptomatic children with T2DM predominantly based on BMI and family history. Screening should be initiated from 10 y of age or at onset of puberty; if puberty occurs earlier, and repeated every 2 y. Screening is done by measuring HbA1C, FPG, or performing OGTT. The OGTT is a more sensitive test than FPG, because OGTT detects patients with diabetes early in the development of their disease when the FPG may not be elevated. It is recommended to use fasting glucose and HbA1C for screening routinely and to use OGTT when results are discrepant, with intermediate (FPG 5.5-7.0 mmol/L or HbA1C 5.7–6.4%) values or clinical suspicion for T2DM is strong. In children with blood glucose in pre-diabetic range, repeat testing should be done annually and LSI initiated to induce weight loss.

HCPs can use the following simple slogan to promote a healthy lifestyle among youth and their families: “5, 3, 2, 1, 0”, designating five [5] portions and more of fruits and vegetables per day, three [3] structured meals per day (including breakfast), two (2) hours or less of television or video games per day an (1) hour or more of moderate to vigorous physical activity daily and no (0) sugary drink or added sugar. It is a great message of prevention to leave to pediatric patients and their parents. His promotion to the general public, through the media, is also recommended [1-3]. Policy makers and Governments should work at different levels in order to create an environment facilitating the acquisition of better eating and physical activity habits among young people and promote their implementation at the school, family and community levels, i.e. by changing the environment so that the choices presented to children are favourable to a healthy lifestyle. They should opt for a strategy named ‘create default options’ by which a pre-selected choice is created with the purpose of producing the desired behaviour change. However, the patient and his/her parents remain free to choose a different option to the proposed one but it becomes more difficult to obtain. In the field of the treatment of obesity or T2DM, «create default options» means changing the food environment and physical activity of the population, so that the default options are not favourable to obesity or T2DM, but favourable to a healthy lifestyle [1-3].

Conclusion

There is some evidence from the National Health and Nutrition Examination Survey (NHANES) that indicates that childhood obesity rates in the US may have stabilized in the past several years, with some decreases in preschool-age groups, although the results should be interpreted with caution. In Canada, currently almost 1 in 7 children and youth are obese. But overall; the rates of excess weight have been relatively stable over the past decade [47]. Consequently, there may be small, but hopeful changes in the overall prevalence of childhood obesity as a result of current obesity intervention and prevention efforts. Since T2DM is highly linked to obesity in the pediatric population, it may not be too speculative to hypothesis that we will also observe a decrease in the prevalence of T2DM in this population in a near future.

Intensive public health efforts are needed and should involve a variety of different stakeholders to target changes at personal, environmental, and socioeconomic levels. Such efforts need to be sustainable, economically feasible, and culturally acceptable so the policies can be effectively implemented across multiple domains. Prevention of T2DM may be classified as primary and include the prevention of overweight or obesity. Prevention of T2DM can also be classified as secondary and include the prevention of weight regain following weight loss, or limiting weight gain in obese people who have not been successful at losing weight. In order to prevent obesity in children and the possibility of developing obesity-associated T2DM, it has been suggested that LSI should focus on those children at high risk for obesity: children with BMIs in the 85th–95th percentiles, who have a family history of obesity in one or both parents or those coming from specific minorities.

Prevention of childhood overweight and obesity may be an even more appropriate target for preventing T2DM, particularly since obesity is very challenging to treat once it is established. For these reasons, organizations such as the National Institute for Health and Care Excellence guidelines (https://www.nice.org.uk/guidance/ng28) recommend a focus on all people achieving and maintaining a healthy weight in order to have the most substantial impact on the prevalence and financial costs of T2DM. The National Heart, Lung, and Blood Institute’s (NHLBI) Expert Panel’s Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents also notes the importance of maintaining a healthy weight in childhood to prevent the development of CVD in adulthood (48). LSI have primarily focused on changing dietary and physical activity behaviors, but interventions designed to prevent T2DM may improve prevention outcomes by targeting additional health behaviors such as sleep habits, stress management or mental health treatment, and smoking [48].

Our prevention efforts have lagged way behind in embracing technology to help effective targeting of this population. Much of our research investigating LSI for young people and their families have relied upon traditional education and behavior change methodology such as paper and pencil self-monitoring of eating and exercise behaviors, hard or soft-bound educational materials and handouts, in-person coaching, and teaching in clinics or other community settings. However, the children and adolescent today are familiar with and more comfortable using web based applications, even available on their cell-phone, to learn new information and to track weight and behavior changes. More research is needed to determine in what ways these web-based applications and computing devices as well as social media can be used to impact health behaviors to reduce the risk of T2DM in youth. Therefore, it is hoped that early screening and intervention to address the unhealthy lifestyle behaviors may help prevent the development of T2DM in later years.

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Counselling on Pediatric T2DM

Introduction

T2DM occurs when insulin secretion is inadequate to meet the increased demand due to insulin resistance then progressively there is apparition of hyperglycemia [1-5]. These children/adolescent are most of the time overweight or obese and commonly are associated either with acanthosis nigricans, PCOS, hyperlipidemia, HTN, and NAFLD. In 75 % of the cases they have strong family history of T2DM [4-5]. The presentation often coincides with the peak of pubertal insulin resistance as explained earlier [8-9].

In contrast to TIDM, children with T2DM may already have microvascular or macrovascular complications by the time they are diagnosed [10]. The differential diagnosis clearly includes T1DM, usually distinguished by the presence of autoantibodies GAD, ICA and IAA; but also diabetes secondary to monogenic causes, transplant and immunosuppression, and other rarer syndromes [9]. The SEARCH for Diabetes in Youth population-based study found that the proportion of T2DM among 10–19 y-olds to vary greatly by ethnicity in the US: 6 % for non-Hispanic whites, 22 % for Hispanics, 33 % for blacks, 40 % for Asians/Pacific Islanders and 76 % for Native Americans [11].

As discussed previously, the average age of T2DM diagnosis in youth is around 14 years, with female predominance. This age of presentation is likely to be related to a time of puberty-mediated insulin resistance in combination with increased body weight. T2DM can be detected while screening asymptomatic children or adolescent because they are belonging to a high-risk population [6, 10].

Some children and adolescents present with diabetes-related symptoms including polyuria, polydipsia, tiredness, blurred vision, vaginal moniliasis, and weight loss [12]. They may also present with acute metabolic decompensation including ketosis, DKA, and HHS but there is no associated islet cell autoimmunity or HLA specificity [12]. Management includes confirming the diagnosis of T2DM; screening for its associated metabolic and vascular complications and initiating lifestyle, dietary and exercise advice to decrease calorie intake and increase energy expenditure combine with metformin or insulin therapy, depending on their glucose control and other risk factors or comorbidities as explained below [10, 12].

Children with T2DM can have three types of clinical presentation: 1). Acute symptomatic: children with T2DM can present acutely with DKA or non-ketotic hyperglycemic coma (NKHC); among children presenting with DKA, 13 % were found to have T2DM; 2). Chronic symptomatic: symptoms are due to hyperglycemia and include polyuria, polydipsia, nocturia and less commonly, weight loss. Adolescent girls may present with vaginal discharge or vulvovaginitis due to monilial infection; 3). Asymptomatic: most commonly, these children are usually identified by routine screening [10, 12]. As mentioned earlier, screening in high-risk groups is recommended to start at the age of 10 years or when puberty starts if it is sooner than that, using FPG every 2 years. The HbA1c target for optimal glycaemic control is less than 7.0%, but the initial target for treatment is negotiated on a mutual agreement depending on their glucose control as discussed below and based on many personal aspects.

Since 95 % of adolescents with T2DM present with obesity, the approach in the counselling of these patients is not much different from the one we use with obese pediatric patients, except for those patients with T2DM that need urgent care. The approach discuss here is the approach mainly recommended in the context of general clinical practice [13-15].

Globally this approach is essentially based on the choice of strategies that will promote the acquisition and maintenance of good lifestyle habits and the motivation to maintain this therapy on the long-term. These strategies will help to change the bad lifestyle habits related to weight gain. Adequate counseling is essential to effectively act on these elements of intervention. To succeed in these tasks, it is highly recommended that family physicians, pediatricians and other HCPs (nurses, dietitians, nutritionists, kinesiologists, psychologists and others) use the “6As” model of counseling that consists of the following mnemonic: “ask, assess, advice, agree, assist, arrange” [13- 15]. This counselling model is use in parallel with the motivational interviewing approach that is very useful to keep the patients in the action and maintenance phases. It is not the purpose of this article to fully detail this approach but mainly to provide the essential information that can be applied in the counseling of T2DM pediatric patients. For more information, please consult the following articles and reviews [13-15].

Ask

In this ‘6 As’ model of counselling, the collaboration of parents is essential and since most children with T2DM first presents with obesity the first think you should do is to ask the permission to talk with the children and their parents about the weight problem of their children [13-15]. Later in the counselling you will have the opportunity to ask questions related to T2DM. Being obese is a delicate issue, because patients and parents are often embarrassed by this condition. It is therefore important not to judge, blame or cause a sense of guilt in patients with weight problems and their parents. You should limit medical jargon and opt for an approach that is sensitive and respectful [13-15].

Asking for permission also allows the HCP identifying barriers and family factors that could have a negative effect on the management of child’s glucose target and child’s body weight. Thus, counseling may be adapted on the basis of these barriers and family factors [13-15]. It is essential that parents are aware of the difficulties, considering that obesity and T2DM are clinical problems which have repercussions on health.

Asking for permission leads to explore attitudes and aptitudes to changes which, among others, are essential to the success of future interventions. Asking permit to determine the perception of children and their parents of their skills to participate in nutritional and physical activity interventions and to make changes in their lifestyle in order to obtain and maintain glucose targets and body weight. It is a way of assessing the availability of the family (children and parents) and social support [13-15].

Ask to assess readiness to change for the patient and his relatives according to the following steps:

  • Pre-contemplation: stage where patients and parents have no intention or no interest to change in the near future.
  • Contemplation: stage where they start to recognize the reality of the problem and that something needs to be done, but without proposing action;
  • Preparation: step where they intend to perform certain actions in the coming months, but nothing concrete is still made.
  • Action: step whose time can range from 1 day to 6 months, where they modify their behaviour and their environment to act on the problem;
  • Maintenance stage: for a period of more than 6 months, during which they work to reduce relapse and consolidate the gains achieved during the stage of action.

During this stage of the counseling, the HCPs can use motivational interviewing to move patients and parents to the next stages of change; first to the stage of action and possibly in the maintenance stage. The goal of this approach is to bring the child and his parents to make decisions based on their values and their resources, rather than to tell them what to do, as is sometimes the case with the traditional approach [13-15]. The motivational interviewing approach includes the following components:

  • Ask the permission to the young and his parents to discuss the issue with the child and their parents. The objective is to provide our support and appropriate information to the patient and his parents.
  • Building the report by using active listening, HCPs, seeks to understand the motivations, values and the barriers to change of the patient and his family; the objective is to establish a relationship of trust with them in order to obtain their cooperation.
  • Encourage discussion on the changes by guiding the conversation towards the possibility of a change in behaviour; list the positive arguments offered by the patient and his parents and promote other positive arguments. The HCPs must not oppose resistance to the changes proposed by the patient or his parents and should encourage them to propose other solutions, as necessary;
  • Guide the conversation towards the realisation of a change and guide the patient and his parents through their change planning in discussing realistic steps and follow-up

Motivational interviewing is a strategy to help patients and their parents to think differently their behaviours and to consider what can be earned by a change. This interview is considered safe and effective for the modification of behaviours associated with obesity [13-15] and is also appropriate for the management of T2DM in pediatric patients. It is based on clarifying expectations, while helping patients and parents to appreciate the values of change and explore the differences between what they think and the reality [13-15]. In addition, motivational interviewing allows building a good patient-doctor relationship, including expressing empathy and congratulating children and parents for good actions towards a positive change in behavior and finding solutions towards failure to achieve appropriate change [13-15].

Assess

Assessment of a child overweight or obese and a child with T2DM should include a complete medical history, a general physical examination, completed by appropriate laboratory tests. Indeed, some children and adolescents present frequently with T2DM-related symptoms including polyuria, polydipsia, tiredness, blurred vision, vaginal moniliasis, and weight loss. The evaluation should include a history of the development of the child, including growth profile, weight gains, compared with the history of growth of parents, a child psychosocial history, including depression, disorders of food, quality of life, self-esteem, as well as a detailed history of risk factor without forgetting the family history of T2DM [10, 12]. The risk factors for the development of T2DM in children discussed earlier should be part of the assessment (see article # 2). Assess if periods are regular, are they painful or heavy, and does the girl suffer from excessive body hair. Consider the risk for obstructive sleep apnoea and assess if there is any nighttime snoring or daytime sleepiness. Other health problems related to obesity include orthopaedic problems such as slipped upper femoral epiphysis; pancreatitis, cholecystitis, and idiopathic intracranial hypertension [13-15].

The medical history should also include the medication list including the, antidepressants and antipsychotic agents and others and those that the mother took during pregnancy, as well as the description of the socio-economic and environmental factors, including home, school and the community environment. The involvement of parents is critical to the assessment of the child and is used to validate the information gathered with the youth [13-15].

Evaluation of nutritional aspects

In this evaluation, it must be relevant to assess for the presence of bad eating habits in children and his family; to assess if the child eats sitting at the family table or in front of the television or in front of other screens; if he eats compulsively, if there is other food problems and if he uses the power of food to manage his emotions [sadness, anxiety, boredom and others] and if the parents use food as a reward [13-15]. Assess also if the child eats food in large quantities, for fun, despite the absence of hunger, and if he feels guilty later. Also assess the consumption of sugary drinks and foods containing added sugars. It is also relevant to assess if the child eats in family or rather in isolation and if he skips meals, especially breakfast [13-15].

Assess with parents for the presence of some habits, such as eating in restaurant in a regular basis and the frequency of meals containing junk food and processed meals [prepared and frozen meals] which often contain a lot of added sugars and salt [13-15]. We must also inquire about the choice of food of the child: is he eating the same thing as the other children in the family? Obviously, in this assessment, it will be recalled that the energy needs of a child may be less or higher than those of the other members of the family. It is essential to assess for the presence of barriers to good nutrition in children and his family, such as the lack of knowledge about the choice, the content, the portions and the cooking, assess with the parents how the child is eating [speed at which meals are eaten, seated at the table, etc.], the ways he resists the temptations and the external pressures promoting excessive intakes, how he deals with the unexpected, the meal planning and, finally, the management of food drives [13-15].

Also assess if the parents know the effects on health of a poor or unhealthy diet, not only in children, but for all members of the family. We must discuss the cost and availability of healthy foods over junk food and understand how personal tastes and culture can affect the choice of food. Finally, we must validate with the child and his parents the information withheld if there were consultations with a nutritionist or a dietitian [13-15].

Evaluation of the level of activity

During this assessment, we must quantify the time allocated to physical activity, i.e. the frequency, duration, intensity, the type of exercise, with which these activities are carried out and finally consider the level of activity in the week compared with the weekend [16]. Also we need to quantify with the young and his parents the time allocated to sedentary behavior, including the time spent in front of the TV or the computer, and the use of video games, phone and other electronic devices. It is important to note the availability for physical activity at home and in school, as well as the obstacles to physical activities. The lack of knowledge, the safety issues and the access to safe equipment, as well as the financial problems in the family that interfere with the regular practice of physical activity should be assessed. Assess if consultations with a specialist in physical activities were performed and analyse the lessons learned from these consultations [13-15]. Finally, it is important to document any conditions that may interfere or be contraindications to regular physical activity in order to adapt the physical activity program to the condition of the patient, as necessary [13-15].

Assessment of psychosocial aspects

Since there is a lot of psychological aspects that we need to take into account in the evaluation of an obese and/or T2DM pediatric patients. It is essential to verify the beliefs of the patient and their parents about the causes and effects of the problem of the child’s, because often these beliefs are based on erroneous perceptions [13- 15]. In addition, do not forget the influences of the cultural and socio-economic problem of the child’s condition. As discussed previously, it is essential to determine the level of preparation for lifestyle changes, the degree of confidence in their ability to make changes as well as their expectations and attitudes towards weight and T2DM management. Also assess the parenting skills; whether parents are authoritarian, or controlling or permissive? It goes the same for family organization: is it a big family, family is disorganized and what is the time available for the child? These elements will help determine the potential for family involvement and the support they can provide to the child [13-15].

Physical examination

It is recommended to include observation of the general appearance, including the severity of obesity and fat distribution in physical examination (peripheral vs. central). Afterwards, you will need to determine the severity of obesity using the BMI. On examination, almost all affected children with T2DM are overweight or obese, with a BMI above the 85th centile for age and sex is defined as overweight while a BMI above the 95th centile for age and sex is defined as obese [13-15]. There is often acanthosis nigricans, a pigmented velvety thickening affecting skin flexures such as the neck, axillae and groins; this is a manifestation of insulin resistance. Blood pressure is often raised (systolic or diastolic blood pressures above 95th centile for age, sex and height. Obviously the physical exam is based on your medical history and should be performed in order to investigate the risk factors and the comorbidities associated with T2DM. Your assessment will be followed by the appropriate laboratory diagnostic tests and those coming from your medical history and physical examination [13-15].

Laboratory testing

A capillary or laboratory plasma or venous glucose is necessary to make the diagnosis of T2DM. It is also helpful to have a baseline HbA1c, to provide an estimation of the duration of hyperglycaemia before diagnosis. In addition to routine measurements should include an assessment for ketone production; urea and electrolytes for assessment of osmolarity and dehydration; assessment for infection [urinary tract, respiratory tract, skin]; autoantibodies to rules out T1DM; and baseline liver function [5].

The C-peptide test is to ensure that the T2DM diagnosis is not being confused with T1DM. C-peptide level is based on blood sugar level and is a sign that the body is producing insulin. A low levels or no insulin C-peptide means that the pancreas is producing little or no insulin. In T1DM, there is a lack of insulin production caused by destruction of β-cells. In T2DM, insulin is produced but the tissues are insulin resistant and in the body therefore there is an increased need for insulin. To combat this, the pancreas produces more insulin but after too long the pancreas loses the ability to produce insulin at all [17]. The other laboratory testing should be performed to assess the complications associated with T2DM.

  • Dysplipidemia should be screened at diagnosis of T2DM and every 1-3 years thereafter as clinically indicated. Dyslipedimia should be assessed by measuring the fasting level of total cholecterol, HDL-C, Triglycerides and calculated LDL-C [6].
  • Hypertension should be screened at diagnosis of T2DM and at every diabetes-related encounter, thereafter [at least twice annually]. The blood pressure should be assessed by using appropriately sized cuff [6].
  • NAFDL should be assessed yearly beginning at diagnosis of T2DM. NAFDL should be assessed by using the ALT and the diagnosis is made when the ALT level is 3 X the normal level [6].
  • Nephropathy should be screened yearly commencing at diagnosis of T2DM. Nephropathy should be assessed by measuring the first morning [preferred] or random ACR (albumin to creatinine ratio). An abnormal ACR will require confirmation at least one month later with either a first morning ACR or a timed overnight urine collection for ACR; Repeated sampling should be done every 3 to 4 months over a 6- to 12-month period to demonstrate persistence [6];
  • Neuropathy should be screened yearly commencing at diagnosis of T2DM. Questioned and examined for: Symptoms of numbness, pain, cramps and paresthesia: vibration, sense, light touch and ankle reflexes [6];
  • PCOS should be screened yearly commencing at diagnosis of T2DM in pubertal females Clinical assessment on history and physical exam should assess for oligo/amenorrhea, acne and/or hirsutism [6];
  • Retinopathy should be screened yearly commencing at diagnosis of T2DM. The assessment should include the seven-standard field, the stereoscopic colour fundus photography with interpretation by a trained reader (gold standard); or the direct ophthalmoscopy or the indirect slit-lamp funduscopy through dilated pupil; or the digital fundus photography [6]

Diagnosis of T2DM

According to the American Diabetes Association (ADA) criteria, T2DM is defined as FPG levels of 125 mg/dL (7.0 mmol/L) and above or plasma glucose levels of 200 mg/dL (11.1 mmol/L) and above two hours after an OGTT, while IGT is defined as plasma glucose levels of 140 mg/dL (7.7 mmol/L) and above after an OGTT. In addition to IGT, another prediabetic state has been described: IFG. IFG is defined as serum fasting glucose levels from 100 mg/dL to 125 mg/dL (5.5- 7.0 mmol/L) [5, 17-18].

Epidemiological studies indicate that IFG and IGT are two distinct categories of individuals and only a small number of subjects meet both criteria, showing that these categories overlap only to a very limited extent in children. Recently, the ADA has recommended testing the HbA1c to diagnose T2DM in children. In particular, 6.5% is the lower limit used to diagnose T2DM? This value was chosen on the basis of cross sectional and longitudinal studies conducted in adult subjects showing that a lower limit of 6.5% identifies about one third of cases of undiagnosed T2DM and that subjects have a long term higher prevalence of microvascular complications. Subjects with an HbA1c between 5.7% and 6.4% have been defined as “at increased risk of diabetes” [5, 17-18].

Differential diagnosis of type 2 diabetes in children

  • Type 1 diabetes. This is associated with diabetes autoantibodies in about 85% of affected children, and children have an absolute insulin requirement [5, 17-18].
  • Apparent type 2 diabetes with coexistent autoimmunity. About 10% of children with an apparent diagnosis of T2DM are found to have antibodies to Glutamate Decarboxylase (GAD), islet cells (ICA), or insulin (IAA). Pancreatic beta cell function is significantly less in antibody positive children and adolescent, and there is more rapid development of insulin dependence. It is likely that these children have T1DM with obesity [5, 17-18].
  • Flatbush diabetes. This is seen in some children of African- Caribbean origin, with a strong family history, sometimes autosomal dominant, and with a female preponderance, no HLA association and diabetes autoantibody negative. These children may present with ketoacidosis or ketosis and require insulin initially; but can be weaned off insulin while maintaining relatively good glycaemic control [5, 17-18].
  • Monogenic diabetes [formerly Maturity Onset Diabetes of the Young]. This usually presents in families with autosomal dominant history; affects no more than 1% of children with diabetes; is not associated with obesity beyond the prevalence in the background population; and is not associated with insulin resistance [5, 17-18].

Advice

This step leads us to discuss the recommendations of national food guidelines about portions, the variety of food to eat each day, as well as the consumption of foods and beverages low in calories, fat, sugar or sodium. We can emphasize to parents the importance of reading the labels of foods and beverages to make healthier food purchases, to choose products that contain fewer calories, fat, sugar and sodium [13-15]. At this step you can also provide information on the risks to health, which can be reduced by increasing physical activity with or without weight loss and highlight the importance of replacing sedentary activities by physical activity of low to moderate intensity such as using the stairs rather than the elevator or even plan a gradual increase in physical activity for previously sedentary patients, for example starting with short sessions of 5-10 minutes and increasing gradually until the desired physical activity of 60 minutes per day [13-15]. Advice can also note that the management of T2DM is to improve the health and well-being of child and also to reduce and maintain an appropriate management of glucose control as reflected by the number indicated on the glucometer scale [13-15].

Management

The current management plans for T2DM involve lifestyle intervention (LSI) and pharmacotherapy, as necessary [17-22]. The treatment of T2DM requires a family-focused plan delivered by a multidisciplinary team with expertise in dealing with T2DM in children and adolescents. Success in treating T2DM requires addressing the main mechanisms that lead to its development, including insulin resistance and β-cells failure. The multidisciplinary team includes a combination of primary care physicians, pediatricians, endocrinologists, diabetes nurse educators, dietitians, physical activity specialists, social workers, psychologists, and behavioral therapists and may also require the involvement of additional medical subspecialties to address the comorbidities or complications associated with T2DM, as necessary [17-22]. It is important to note that T2DM is associated with other comorbidities that are related to insulin resistance, and some of these comorbidities are present at diagnosis [17-22].

The management plan should be intensive with frequent contacts with family and youth and personalized to the individual patient taking into account the family’s financial resources and being receptive and respectful of ethnic and cultural attributes of the family [13-15]. Engaging the patient and family early and frequently is critical to minimize attrition, which is a common problem in this population. The goals of T2DM management include: 1). achieving and maintaining glycemic control; 2). weight maintenance or weight loss if possible and prevention of weight regain; 3). acquisition of healthy lifestyle habits and skillsets; 4). management of comorbidities, and; 5]. prevention of complications [17-22].

One important study has been published about the role of different treatment modalities in T2DM is the treatment options for T2DM in youth (TODAY) study [23-24]. This was a large, longitudinal, randomized, multicenter study that recruited 699 children and adolescents with an age range of 10–17 years and female to male ratio of 2: 1. These patients were randomized to three treatment groups that included metformin alone or in combination with LSI or rosiglitazone. The mean time since diagnosis of T2DM was 7.8 months and HbA1c less than 8% on enrollment. The primary outcomes, defined as failure to maintain HbA1c less than 8% over 6 months or metabolic decompensation requiring insulin therapy at diagnosis or restarting after stopping insulin within 3 months, occurred in 51.7%, 46.6%, and 38.6% in the above groups, respectively. Metformin alone was no different from metformin plus LSI in improving metabolic outcomes, and higher failure rates in black participants were noted. Combination therapy of metformin plus rosiglitazone offered better success rates especially in girls but was associated with more weight gain [23-24]. This study revealed that, even with intensive LSI and pharmacotherapy, a significant number of T2DM patients fail to achieve adequate glycemic control. In addition, the treatment options available to youth with T2DM are limited when compared to adults, with insulin and metformin being the main agents used. This emphasis the need to find solutions for the development of clinical trials testing new molecules adapted to pediatric patients presenting with T2DM. This issue will be discussed in depth in the articles number 5. Similarly with the development in the use of pharmacogenomics and the pharmacokinetic, it will become possible to individualize therapy for the treatment of T2DM; to offer treatment that will be more efficient to a specific individual with less adverse drug reactions. This issue will be further discussed in the article number 6 of the current issue.

The risk of microvascular and macrovascular complications in adults increases with both the duration of T2DM and lack of glycaemic control, so it is vital to achieve and sustain metabolic control through normalization of glycaemia; and control of co-morbidities. Therefore, reducing the risk of microvascular and macrovascular complications may require even tighter and longer glucose control in childhood with T2DM than in adults [23-24].

Life style intervention Program [LSI]

The main emphasis in the management of T2DM is on lifestyle modification [20-22]. LSI defined as an increase in physical activity, decrease in sedentary activities and a change in dietary patterns that result in a daily caloric deficit, is considered the main component in the management of T2DM and its-associated complications in pediatric patients [20-22]

LSI works best when the whole family is engaged in learning process about supporting the child, and these recommendations may be helpful for other family members who may suffer from obesity and but not still diagnosed T2DM [13-15]. Parents and caregivers need to be informed of the importance of modeling healthy behaviors in a way to encourage children to acquire appropriate lifestyle habits [13- 15]. They also need to maintain positive reinforcement of success and avoid penalizing failures. The key is to build collaborative relationships and avoid combative interactions when it comes to managing T2DM with their child [13-15]. The present section examines the lifestyle management efforts to prevent and treat T2DM and its associated co-morbidities in children.

Nutrition

Regarding nutrition, the focus should be on formulating a nutrition plan that involves food composition and eating behaviors that reduce excess caloric intake [13-15]. Recommendations regarding controlling portion size and setting up regular meal and snack times are important. Equally important is eating meals as a family and elimination of distractions during meal times including TV, computers, or other disturbances to slow down eating and improve social interactions [13-15].

Other recommendations include avoiding snacking especially while watching TV, using the computer, and late at night. In addition, the elimination of sugary drinks and foods with high fat or caloric content is also critical in reducing caloric intake in order to promote weight maintenance or weight loss and better promote glucose control.

Parents, caregivers, and youth need to be taught how to read food labels to understand the nutritional value of consumed foods and to emphasize the importance of consuming less fat including saturated fatty acids, increasing fiber intake, and reducing sugar intake and eating out in restaurant or eating prepared food that contains a lot of sugar and salt [13-15].

The most prevalent goal is to stop weight gain in order to obtain better glucose control. The focus may not always be on caloric restriction as that may interfere with growth but the focus should be on keeping the blood glucose and HbA1C within the normal range. This can be done through lifestyle changes such as decrease of high calorie and high fat foods, as well as foods high in simple carbohydrates, especially sugar [13-15].

Nutrition education should be provided in a way that encourages regular meals and regular healthy snack each day, as well as regular physical activity. Total carbohydrate consumption will need to be monitored as recommended by the diabetes nurse. These carbohydrates should be complex carbohydrates [esp. legumes, fruits, vegetables, and oats] that help the patient increase his fiber intake as it takes the small intestine longer time to absorb high fiber foods and therefore affects less glucose levels.

Because many patients with T2DM their kidney is not functioning properly; as demonstrated by the presence of protein in their urine, they will have to be careful not to consume more than 0.8 g/kg or ~10% of total kcal at least until there is no longer protein present in their urine and then the patients should consume no more than 20% of their total kcals from protein. Their total fat consumption should not exceed 25-35% of total kcal and saturated fat should not be higher than 7% of total kcals [13-15].

The Committee [Consensus statements of Focus on a Fitter Future on T2DM prevention using diet and physical activity] supports dietary intervention to manage weight, specifically a low glycemic index [GI] diet implemented by registered dietitians, to influence metabolic risk factors for T2DM in pre-diabetic children. More-severe carbohydrate restriction may be considered for severely obese children with pre-diabetes under medical supervision [25]. Reducing sugar-sweetened beverages (SSBs) intake in children and adolescent has been shown to have a positive impact on weight. Plourde [13-15] and others go even further on this issue by recommending “0” SSB or added sugar to overweight and obese children. Please also note that the simple slogan “5, 3, 2, 1, 0” discussed in the prevention section is also applicable in the treatment approach of pediatric T2DM.

Intensive dietary interventions without adjunct exercise therapy elicit a ~2 % (95%CI −2.40 to −1.23 %) weight loss defined as weight, BMI, % body fat, waist circumference or skinfold thickness, relative to controls receiving standard dietary recommendations. In a recent position statement from the Academy of Nutrition and Dietetics, four dietary strategies for eliciting weight loss in overweight and obese children and adolescents were recommended: (1) modified traffic light diet, (2) low carbohydrate diet, (3) reduced glycaemic load (GI) diet, and (4) non-diet approach. Systematic reviews have determined that these strategies are effective in improving body composition in the short term among overweight and obese children and adolescents [25].

Physical Activity

According to the 2008 Physical Activity Guidelines for Americans, “being physically active is one of the most important steps that Americans of all ages can take to improve their health”. Children and adolescents should engage in 60 min daily of moderate-to-vigorous PA (MVPA). The recommendations by the American Academy for Pediatric and the World Health Organization are essentially identical. Current data suggest that only 8% of U.S. youth meet the 60-min/day MVPA recommendation, based on accelerometer data, and that many children and adolescents exhibit sedentary behavior and are subsequently largely physically inactive. A similar picture is also observed in our youth in Canada [26].

We should focus on the health risks of sedentary behavior because physical inactivity has been identified as the fourth leading risk factor for global mortality. Therefore, it is essential that more information be obtained regarding physical activity and sedentary behaviors in T2DM youth in order to be able to intervene on the main sedentary behaviours as demonstrated in a recent article by Plourde [16]. The beneficial effects of increased physical activity and decreased sedentary behavior are extremely important in youth with T2DM because of the markedly increased long-term risk of cardiovascular disease in this population compared to persons without T2DM [13-15, 27].

The independent role of exercise training without caloric restriction on reducing insulin resistance is recently recognised as an adjunct in the management of T2DM in children. In fact, some recent studies observed that both the aerobic and resistance type of exercise training without calorie restriction resulted in meaningful changes in insulin sensitivity, suggesting that exercise alone is an effective therapeutic strategy in overweight and obese youth. As observed in adults, this beneficial effect occurs through multiple adaptations such as improved glucose uptake of skeletal muscles and body composition changes in overweight children and adolescents [13-15, 27-28].

Physical activity and cardiorespiratory fitness in children and adolescents are both correlated with insulin sensitivity independent of adiposity, especially when physical activity is at higher intensities. Fedewa and colleagues conducted a meta-analytic review to determine the effect of exercise training on predictors of T2DM in children and adolescents. They found small to moderate effect sizes for exercise training on fasting insulin providing support for the inclusion of physical activity in lifestyle management programs to prevent and treat T2DM in youth [29]. Taken together, results from these systematic reviews reveal that intensive, structured lifestyle interventions, particularly those that include both exercise and dietary modifications, yield modest but meaningful improvements in adiposity in obese children and adolescents [13-15]. These data suggest that similar strategies may also be beneficial for obese youth living with T2DM. Among overweight and obese youth, lifestyle interventions confer favourable effects on serum lipoprotein profiles, fitness, insulin sensitivity and systolic blood pressure. These results explain why often it is not necessary to introduce medication to treat dyslipidemia and/or HTN in pediatric or adult patients presenting T2DM as physical activity and modest weight loss are often sufficient to correct these T2DM-associated disorders [13-15, 28].

A) Intervention Techniques:

Techniques taught to children and adolescents as well as family members include self-awareness, goal setting, stimulus control, coping skills training (CST), cognitive behaviour strategies and contingency management. Importantly, parents played a key role in the intervention and were taught to play role modelling of healthy behaviours and coping strategies. In the recent book and review articles by Plourde [13-15] there are good examples on how to use these techniques with youth presenting weight problems and their family members? Studies demonstrate that these techniques are associated with significant reductions in BMI, body weight, body fat and percent body weight and fat. The improvement in body composition was associated with significant improvements in total cholesterol and fasting insulin. These effects also translated into an increased rate of remission from IGT in obese children with abnormal glucose levels. The effects of these interventions techniques, suggest that under ideal conditions, clinically relevant weight loss and positive metabolic health outcomes are achievable and sustainable in obese children and adolescents by using these techniques [13-15].

B) What are the established barriers to exercise participation?

Children and adolescents with T2DM experience similar exercise barriers than those who are overweight or obese, such as lack of time and motivation, inability to access facilities and others [13- 15]. These individuals are most of the time are overweight or obese and may feel that the benefits of exercise do not provide a sufficient gain and commonly report physical discomfort, boredom, and lack of time as the major barriers to exercise [13-15]. Similarly, children and adolescents with T2DM are more likely to be discouraged from exercising because of physical discomfort. Body-related concerns, such as being seen by others while exercising, are also frequent barriers to exercise, particularly in overweight girls [13-15].

Another factor to consider with regard to exercise participation in both children and adolescents is peer influence. With peer presence, some studies suggest children are able to increase participation by 54%, however negative peer perceptions may also have a negative impact on exercise in those children and adolescent. Given the social stigma associated with being overweight or obese, and the perceived negative body image barrier of adolescents, peer influence may impede obese individuals from exercising [13-15]. Importantly, recent data also suggests adverse exercise kinetics may be a significant barrier to sustaining an exercise program in children and adolescents with T2DM. Nadeau et al showed that children and adolescents with T2DM have decreased maximal oxygen uptake (VO2 peak), lower maximal work rates, and significantly prolonged VO2 kinetics compared with obese non-diabetic controls. Thus, it appears that exercise at the required intensity for health benefits may be inherently more difficult, uncomfortable, and the metabolic adaptations to intense effort slower, resulting in greater levels of overall discomfort for those with T2DM [30].

C) Strategies to overcome barriers to participation.

Adolescents with T2DM may be relatively unconcerned about long-term consequences of poor metabolic control. Also, these youth often have other family members with T2DM, and modeling of good exercise habits may thus be problematic within the household family unit. Therefore, it is important for both youth and parents to be aware of and understand the long-term consequences of poorly managed T2DM.

Support from parents and family members are also critical for encouraging exercise in children and adolescents with T2DM. When children are given action-oriented support, rather than verbal prompts, they are more likely to be active [13-15]. Not only should families engage in activities with children and adolescents, but they should also help the child overcome body-related barriers [13- 15]. It is important to help youth understand the benefits of exercise and establish concrete realistic goals. Additionally, teaching those that are overweight or obese to reduce the value of esthetics can help reduce social pressures and improve body-esteem, could help them to better adhere to an exercise prescription.

For adolescents specifically, support from peers with T2DM could be beneficial. Adolescents may find it very helpful to share and learn from experiences of other adolescents with T2DM, and the absence of peers may negatively influence management. Along with support and education, it is important to consider the child’s interests and capabilities. It is important to be aware that enjoyment is a key and developmentally important factor in exercise for children and adolescents, and may improve adherence to exercise. Self-efficacy should also be considered to avoid setting unattainable goals that can diminish adherence to physical activity programs [13- 15]. Therefore, as in overweight or obese children and adolescents, individual behavioral approaches with family support should be emphasized to facilitate exercise in youth with T2DM.

Sedentary behaviors

Increased screen time is associated with increased sedentary time and obesity. While there are no specific guidelines to address screen time use in T2DM, the recommendations for prevention of childhood obesity by the American Academy of Pediatrics is limiting screen time to two hours per day excluding use for academic purposes or for work and seem reasonable to follow in T2DM [13-15]. Sustaining LSI is a challenge in the T2DM population, and in one study only 17% of patients have lowered their BMI over 1 year of LSI implementation, and 23% were off medications over 2 years. LSI is essential not only to manage T2DM per se but more so to deal with its associated complications including fatty liver disease and to modulate future CVD risk [13-15].

Electronic media use in T2DM youth seems to be very high with on average 3.6 h for boys and 2.9 h/day for girls, of which the majority is spent watching TV. Rothman et al. reported that only 32% of their population watched one hour of TV or less per day, while the remained watched 2 or more hours [31]. Compared to youth without diabetes, those with T2DM seem to engage in markedly more sedentary behaviors. Minimizing sedentary behavior during waking hours is likely beneficial for the prevention and management of T2DM in the pediatric population. Evidence suggests that ~80% of waking hours during the preschool years are spent sedentary [31]. Therefore, there is a lot of room for reducing this component of LSI and increasing physical activity to improve the management of pediatric patients with T2DM.

Pharmacotherapy

LSI is important to provide the basis for acquiring healthy lifestyle habits in T2DM. Even though, the success rates of maintaining glycemic targets based on LSI alone is important, often starting pharmacotherapy at diagnosis is appropriate [19, 32-36]. The aims of pharmacological therapy are to decrease insulin resistance (e.g. metformin), increase insulin secretion [e.g. sulphonylureas, not recommended in children], slow postprandial glucose absorption [acarbose, not recommended in children], or finally to increase glucose entry into cells (insulin). For children, the choice is limited to insulin and metformin as these are the only two molecules authorised for the treatment of T2DM in pediatric patients [6].

Metformin

Metformin is now considered as first line oral antidiabetic drug (OAD) in pediatric population with T2DM by ADA (American Diabetes Association) and ISPAD (International Society of Pediatric and Adolescent Diabetes) [17-18]. US-FDA has approved metformin in children above 10 y of age. It is a biguanide that lowers blood glucose levels via several mechanisms including: i). reducing hepatic glucose output by inhibiting gluconeogenesis; ii). increasing insulin-stimulated glucose uptake in muscle and adipose tissue; iii). inhibiting inflammation in cells by inhibiting the NFκB pathway which, when active, interferes with insulin signaling; iv), increasing fatty acid oxidation in muscle and inhibiting fatty acid synthesis in fat and liver by upregulating AMPK activity; and v) enhancing the secretion of GLP-1 from the gut [19, 32-36]. Metformin has an initial anorexic effect and may result in modest weight loss. It lowers HbA1c by 1-2% and is to be taken with food to minimize its gastrointestinal (GI) adverse drug reactions including nausea, vomiting, diarrhea, and abdominal pain [19]. There are slow release preparations such as Glucophage XR and others that have less GI side effects and are taken once daily, which may improve compliance, and pediatric trials are ongoing to evaluate their efficacy.

Importantly, metformin use is rarely associated with hypoglycemia. GI adverse events are common with metformin but they can be minimized by taking the OAD after meals, slow titration of doses or by the use of extended release preparations. Titration of metformin is done as follows: start with pills of metformin 250 mg once a day for 3 to 4 days and if tolerated, increase to 250 mg twice daily. The dose is slowly titrated upwards by 500 mg per week over a period of 3 to 4 week to a maximum of 2000 mg/day, given as two divided doses or as single dose of sustained release preparation. Metformin reduces HbA1C by 1–2 % [19]. Metformin should be avoided in children with severe renal impairment, hepatic dysfunction, or cardio respiratory dysfunction due to the risk for lactic acidosis [19]. However, the risk of lactic acidosis is relatively rare. Most HCPs treat patients with new-onset T2DM who are asymptomatic, have HbA1c less than 9%, or have blood glucose concentrations in the low to mid-200s with metformin before initiating insulin treatment [17-18].

The results of the TODAY study demonstrated that the rates of treatment failure include HbA1C ≥ 8.0 % or metabolic decompensation were 51.7 % with metformin alone, 38.6 % with metformin plus rosiglitazone, and 46.6 % with metformin plus LSI. Metformin plus rosiglitazone was associated with a 25.3% decrease in treatment failure as compared with metformin alone (P=0.006); the outcome with metformin plus LSI was intermediate but did not differ significantly from the outcome with metformin alone or with metformin plus rosiglitazone [23]. But it is essential noting that the rates of failure observed with metformin alone or with metformin plus LSI are rather high.

In the review made by Scheen AJ [37], it has been shown that metformin is carried into the hepatocytes by an organic cation transporter 1 (OCT1), which is encoded by the gene SLC22A1. The data from animal and human have demonstrated that OCT1 is important for the therapeutic action of metformin. These data also indicated that the genetic variation in OCT1 may contribute to variation in response to the OAD [38]. The effects of metformin in OGTT were significantly lower in individuals carrying the reduced function polymorphisms of OCT1. Therefore, it is possible to explain that the rate of failure observed in the TODAY study might be explained in part by this genetic variation in OCTI [37].

Severe metformin intolerance has also been associated with this reduced function of the OCT1 variants. In the GoDARTS study, GI intolerance to metformin has been observed four times more frequently in individuals with the two reduced-function of the OCT1 alleles who were treated with the OCT1 inhibitors [39]. These results, which were confirmed in another study, suggest that high inter-individual variability and the severe GI intolerance to metformin shares a common underlying mechanism [40]. These data seems to suggest that patients carrying these genetic variations in the OCT1 respond less to metformin and are more associated with GI adverse drug reactions. Which means that the identification of this genetic variation before initiating the treatment with metformin could contribute to a more personalized and safer metformin treatment [40]? Finally, genetic variants associated with metformin response could be used to predict both the glucose-lowering efficacy and tolerance profile of metformin treatment in patients before they take the drug, a step forward in the path towards personalized medicine [41-42]. The latter concept will be further discussed in the article number 7 of the current issue.

Failure of metformin as monotherapy indicates the need for addition of insulin. The goals of therapy should be to achieve HbA1C

Insulin

It cannot be stressed enough that if there is any doubt about the diagnosis of T2DM, then it is much safer to commence insulin treatment and revise the diagnosis later [35-36]. As you will see in the article number 5 this approach complicates the eligibility of pediatric T2DM patients in participating in clinical trials having the goals of finding more efficient new OAD to treat this complicated metabolic disorders.

Insulin reduces islet glucotoxicity and has a paradoxical effect on improving insulin sensitivity in the context of insulin resistance. Insulin is used at presentation if the patient is hyperglycemic including blood glucose > 11.1 mmol/L, ketotic, or ketoacidotic or if the HbA1c is ≥ 9%. The goal of insulin therapy is to reverse the acute metabolic decompensation noted in some patients at presentation and may be used for few weeks at diagnosis and then is withdrawn gradually thereafter [35-36].

In some cases, it is not possible to de discharged from insulin. In addition, insulin is usually needed for few years after the initial diagnosis on a maintenance basis due to β-cell failure. There are few pediatric data on the insulin regimens used, but they all seem to have equal efficacy [35-36]. Insulin may be the only prescribed agent in pediatric patients with T2DM. The main side effects of insulin include weight gain and hypoglycemia; two major adverse effects that need close monitoring.

Other Medications

There are limited data on the use of additional OAD to treat T2DM in pediatric patients compared to adults. Amylin (pramlintide), incretinmimetics/ glucagon like peptide-1 receptor agonists (exetanide), DPP-1 V inhibitors (vildagliptin, sitagliptin, saxagliptin, linagliptin) and á-glucosidase inhibitors are not approved in patients

Sulfonylureas [SU]

Sulfonylureas are insulin secretagogues and therefore are only effective if residual pancreatic insulin secretion is present. They bind to the sulfonylurea receptor on the β-cells; this results in closure of the KATP channel and depolarization of the cell membrane and then calcium influx through the calcium channels, which results in insulin release [19, 32-36].

From a physiologic point of view, the clinical response to sulphonylurea has been widely associated with a number of gene polymorphisms, particularly those involved in insulin release [37]. The hepatocyte nuclear factor- 1 alpha (HNF1-α) gene mutations are the commonest cause of monogenic diabetes. Diabetic patients with HNF1-α gene mutations are particularly sensitive to the glucose-lowering effect of sulphonylureas and therefore patients presenting these mutations can respond more efficiently to this OAD [43].

As far as T2DM is concerned, genetic markers of genes that predict treatment outcomes of sulphonylurea therapy have been recently reviewed: especially, the ABCC8 (SUR1), KCNJ11 (Kir6.2), TCF7L2 (transcription factor 7-like 2), and IRS-1 (insulin receptor substrate-1). A convincing pattern for poor sulphonylurea response was observed in Caucasian T2DM patients with the rs7903146 polymorphisms of the TCF7L2 gene [44-45]. Another example is the Arg (972) insulin receptor substrate-1 (IRS-1) variant which is associated with an increased risk for secondary failure to sulphonylurea [46].

In addition to the effects of genetic variants on target genes, variation in the enzymes responsible for sulphonylurea metabolism also can affect the OAD efficacy [37]. An increased sensitivity to sulphonylurea, with a potential higher risk of hypoglycaemia, has been reported in T2DM patients with reduced function alleles at CYP2C9, resulting in a reduced metabolism of the OAD [47]. As a consequence, the total oral clearance of all studied sulphonylureas [tolbutamide, glibenclamide (glyburide), glimepiride, glipizide] was only about 20% in persons with the CYP2C9*3/*3 genotype compared with carriers of the wild type genotype CYP2C9*1/*1, and the clearance in the heterozygous carriers was between 50% and 80% of that of the wild type genotypes [48]. However, the resulting differences in sulphonylurea-associated glucose-lowering effects were much less pronounced. Nevertheless, CYP2C9 genotype-based dose adjustments derived from PK studies may reduce the incidence of adverse reactions, especially hypoglycaemia [48]. However, because of important limitations in available studies, further studies are necessary before developing personalized medicine for T2DM management with sulphonylurea [49].

Thiazolidinediones [TZD]

Rosiglitazone and pioglitazone are the only remaining OADs from TZD family in clinical use, and rosiglitazone was used in the TODAY study [23]. Rosiglitazone binds to peroxisome proliferator-activated receptor gamma [PPAR-γ] in metabolic cells. This is a transcription factor and master regulator of fat and carbohydrate metabolism and is an insulin sensitizer. In adults, rosiglitazone reduces HbA1c by 0.5–1.3% [19].

From a biologic point of view, CYP2C8 and CYP3A4 are the main enzymes catalyzing the biotransformation of pioglitazone, whereas rosiglitazone is metabolized by CYP2C9 and CYP2C8 [48, 50]. Please note that troglitazone, a TZD has been withdrawn from the market because of hepatotoxicity. The genes coding for the CYP2C8 and the PPAR-γ are the most extensively studied to date and the selected polymorphisms may contribute to the respective variability in the pioglitazone pharmacokinetics and pharmacodynamics, which may impact both the efficacy and toxicity of the OAD [51]. The CYP2C8*3 polymorphism was found to be associated with lower plasma levels of rosiglitazone and thus with a reduced therapeutic response but also to a lower risk of developing oedema. These observations suggest that the individualized treatment with rosiglitazone on the basis of the CYP2C8 genotype may therefore be possible [52]. However, the studies that looked at the association between CYP polymorphisms and TZD toxicity were inconsistent and generally did not produce statistically significant results [53].

Specific genetic variations in the genes involved in the pathways regulated by TZDs could also influence the variability in the treatment with these OADs [54]. A first study showed that the Pro12Ala variant in the PPAR-γ gene does not affect the efficacy of pioglitazone in patients with T2DM, suggesting that the glucose-lowering response is independent from the pharmacogenetic interactions between PPAR-γ and its ligand pioglitazone [55]. However, in a more recent meta-analysis, which synthesized the currently available data on the PPAR-γ Pro12Ala polymorphism, the carriers had a more favourable change in fasting blood glucose from baseline as compared to the patients with the wild-type Pro12Pro genotype [51].

In a study investigating the influence of the S447X variant in the lipoprotein lipase [LPL] gene on the response to therapy with the TZD pioglitazone, the S447X genotype conferred a statistically significant reduction in the glucose-lowering response rate to pioglitazone as well as a less favourable lipid lowering response relative to the S447S genotype [56]. In a study in Chinese patients with T2DM, the adiponectin gene polymorphism rs2241766 T/G was associated with a higher pioglitazone efficacy [57]. Therefore, pharmacogenomics and pharmacogenetics studies may be important tools in drug individualization and therapeutic optimization when prescribing TZDs in patients with T2DM [54]. However, progress still remains to be made before more evidence becomes available in children. This important issue will be further discussed in a following article.

Incretin Mimetics

This class of OADs includes glucagon-like peptide-1 (GLP-1) receptor agonist, which is a peptide secreted by the L cells of the small intestine in response to food, and has a half-life of 2 minutes [32], making it impractical for clinical use. It enhances insulin secretion in response to glucose, suppresses glucagon production, delays gastric emptying, prolongs satiety, and reduces HbA1c and weight. It is given subcutaneously twice daily, which may limit compliance in teens. Some of its side effects include nausea, vomiting, diarrhea, dyspepsia, and headache [19].

Studies are ongoing to validate its use in T2DM pediatric patients. Incretins are gut hormones that were originally discovered because studies of insulin release demonstrated greater insulin release to oral glucose than to glucose given intravenously. It was then postulated that this difference in insulin secretion was secondary to the effect of hormones produced by the gut and to the effects of incretins. Although there are several incretins, only three of them, the gastric inhibitory peptide (GIP) and the glucagon-like peptides 1 and 2 [GLP- 1 and GLP-2] are strong insulin secretagogues [32].

GIP also stimulates glucose uptake by adipocytes, thus enhancing lipogenesis. Although all three of these incretins can improve glucose homeostasis, the late phase insulin response to GIP was found to be absent in individuals with T2DM. GLP-2 is an epithelial growth factor, so studies have focused on GLP-1 as a potential therapeutic OAD. GLP-1 is secreted by the L cells of the distal ileum largely in response to carbohydrate and fat, which act directly on the L cells to stimulate GLP-1 secretion. This in turn results in insulin secretion and in a concurrent decrease in plasma glucose concentrations. Studies in adolescents have shown that these drugs have helped them to lose weight [32] which is essential for reducing insulin resistance in patients with T2DM. The most common adverse drug reaction associated with this drug is pancreatitits [19]. This underscores the need for continuous monitoring for serious adverse events with the use of this OAD as it has only been in use for a relatively short time. This serious adverse drug reaction would certainly limit its development for the treatment of T2DM in pediatric patients.

The most commonly used GLP-1 agonists are exenatide (Byetta), given twice daily with meals, and liraglutide (Victoza), a once daily analogue [19]. In order to attempt to improve adherence with an injectable medication in patients with T2DM, a long-acting analogue (LY2189265) that can be given once weekly has been developed. Studies of pharmacodynamics of escalating doses of LY2189265 in six patients indicated increase in glucose dependent insulin secretion and decreased glucose excursions during an OGTT at all doses studied (0.1– 12 mg), but there was an increased pulse rate with doses of at least 1.0mg and an increased diastolic blood pressure with doses of at least 3.0 mg [58]. GI adverse drug reactions also increased with increasing doses, indicating that the low dose, but not the high dose, appears to be well tolerated and effective. Further research are needed before these OADs be authorised in pediatric patients.

DPP-IV Inhibitors

These OADs inhibit dipeptidyl peptidase- (DPP-) IV, the enzyme that degrades incretin hormones. DPP-IV inhibitors thus increase the activity of endogenous GLP-1 [32]. They do not affect gastric emptying, satiety, or weight; issues that are important for youth with T2DM, since most of whom are overweight or obese. They are given once daily orally with metformin, and there are no pediatric data to evaluate their role in T2DM.

Amylin

This is a peptide released with insulin by the β-cells at a ratio of 1: 100. It reduces glucagon production, slows gastric emptying, and reduces food intake. It is given to patients who are on insulin and causes a mild reduction in the HbA1c and mild weight loss but is associated with nausea and hypoglycemia that requires the reduction of insulin dosing by as much as 50% [32]. There are no data on its use in T2DM children and adolescents. Amylin, is an islet amyloid polypeptide co-secreted with insulin by the β-cells of the pancreas [19].

Pramlintide acetate (Symlin) was approved by the FDA in 2005 for adults with T1DM or insulin-dependent T2DM. It is given subcutaneously prior to meals with insulin. The most clinically significant risk is hypoglycemia, especially in individuals with T1DM. Side effects are mainly GI, including nausea, anorexia, and vomiting. In the late 1990s and early 2000s pramlintide acetate was demonstrated to improve glycemic and weight control through the control of postprandial glucose excursions in adults with T1DM and insulin- dependent T2DM [32]. But this molecule has not been approved yet in children and adolescents for the treatment of T2DM.

Alpha Glucosidase Inhibitors

This class of OADs delays the absorption of carbohydrates by inhibiting the breakdown of oligosaccharides in the small intestine. It can reduce HbA1c by 0.5–1% [19]. It needs to be taken before every meal, and flatulence is a side effect [19]. Both of these reasons make them less desirable for the T2DM teen.

Bariatric Surgery

In adults, bariatric surgery results in the remission of T2DM and discontinuation of medications in many situations [6]. In the only pediatric study published so far, 11 adolescents with T2DM who underwent Roux-en-Y gastric bypass were compared to those who were medically managed; the surgical group had around 34% reduction in BMI and improved their control of HTN and dyslipidemia. In 10 patients from the surgical group, T2DM disappeared and they did not require pharmacotherapy [59]. The experience with bariatric surgery in adolescents with T2DM is very limited with specific eligibility criteria including BMI >35 kg/m2; Tanner stage IV or V, and skeletal maturity. Furthermore, all other approaches must be taken first, primarily the initiation of a healthy lifestyle that includes a healthy diet as well as exercise for a period of 6-12 months [13-15]. As this is a new procedure in T2DM teens, longitudinal studies are needed to validate its feasibility.

Extremely obese diabetic adolescents experience significant weight loss, remission of T2DM, improvements in insulin resistance, improvements in beta-cell function, and CVD risk factors after Roux-en-Y gastric bypass surgery [60]. Although the long-term efficacy of Roux-en-Y gastric bypass is not known, these findings suggest that it is an effective option for the treatment of extremely obese adolescents with T2DM. In RCTs of treatment with the gastric banding procedure vs. a lifestyle weight loss program for adolescents with severe obesity, more than 50 % weight loss was achieved with complete resolution of the metabolic syndrome and insulin resistance with the surgical approach and this effect was sustained over 2 y of follow-up after the surgical procedure [60-61].

Management of Comorbidities/Complications

It is not the purpose of this section to discuss the management of all the complications associated with T2DM and the discussion will be limited to the most common ones that include hypertension, renal impairments and dyslipidemia. The readers can have access to further information concerning the management of other comorbidities by consulting previous documents by Plourde [13-15].

Hypertension

Screening for high blood pressure should begin at the time of diagnosis of T2DM and continue to be taken at every diabetes-related clinical encounter thereafter, since up to 36% of adolescents with T2DM have HTN. The Treatment of high normal blood pressure i.e., systolic or diastolic blood pressure consistently above the 95th percentile for age, sex and height should include LSI to reduce weight. If target blood pressure is not reached after 3 to 6 months of LSI, pharmacologic treatment should be considered. ACE inhibitors are teratogenic and should be cautiously used in sexually active adolescent girls. The goal of treatment is a blood pressure <130/80 or below the 90th percentile for age, sex and height whichever is lower. Combination therapy may be required if HTN does not normalize on single agent. If ACE inhibitors are not tolerated angiotensin receptor blocker (ARB) can be considered. [6, 17]. Most of the time minimal weight loss and adherence to LSI is sufficient to correct HTN in overweight or obese T2DM patients.

Renal Impairments

Urine albumin at concentrations >30 mg/g creatinine should be considered as a continuous risk marker for CVD events. Microalbuminuria should be treated with an ACE inhibitor or if not tolerated, ARB similar to the management of HTN. Combination therapy may be required if albuminuria does not normalize on single agent. In patients with T2DM, HTN and microalbuminuria, both ACE inhibitors and ARBs have been shown to delay the progression of macroalbuminuria In patients with T2DM, HTN, macroalbuminuria, and renal insufficiency (serum creatinine >1.5 mg/dL), ARBs have been shown to delay the progression of nephropathy [6, 17]. The presence of renal impairment should be considered when selecting both the type and the dose of oral glucose-lowering agents in patients with T2DM [19]. More particularly, this is the case for metforminm, incretin-based therapies (DPP-4 inhibitors and GLP-1 receptor agonists) and SGLT2 inhibitors. The risk of hypoglycaemia is also increased in T2DM patients receiving sulphonylureas in the presence of renal insufficiency [19].

Dyslipidemia

Children with T2DM have an increased prevalence of dyslipidemia with 44.8% of Canadian children reported to have dyslipidemia at the time of diagnosis [6]. Testing for dyslipidemia should be performed soon after the diagnosis when blood glucose control has been achieved and annually thereafter. The goal is LDL-cholesterol 1.9 mmol/l. In children with familial dyslipidemia and a positive family history of early CVD events, a statin should be started if the LDL-C level remains >4.1 mmol/L after a 3- to 6-month trial of LSI. As for HTN, most of the time minimal weight loss and adherence to LSI is sufficient to correct dyslipidemia in overweight or obese T2DM patients.

Mutual agreement

We are making progress in terms of how we are treating T2DM. We are now going for a more individualized approach that is why this component of the “6As” model of counselling is so important. Through our understanding of some of the pathophysiology of T2DM, disease and patient’s characteristics we are now able to be more patient-specific on treatment targets. Specifically, the ADA has put forward a very nice graphical representation of individual physiologic and patient-centered aspects [https://durobojh7gocg.cloudfront.net/ content/diacare/38/1/140/F1.large.jpg] that one should incorporate in the selection of the treatment target that we can then negotiate with the patient in the ‘agree’ step of this “6As” model of counselling. This is not something that takes a long time. When we sit with a patient, it takes only few minutes to discuss some of their disease characteristics such as their risk for hypoglycemia, how long they have had the disease, whether they have other important comorbidities, their risk of weight gain, their motivation status. Based on this information, you can easily achieve a mutual agreement on an initial treatment target HbA1c goal. I recommend that you put it in the patient’s chart so that other HCP who see the patient will have a perspective and a rationale for why you are approaching treatment the way you do [13-15].

Again, since for most of the patients with T2DM are overweight or obese, it is agreed that obtaining an ideal BMI is not a realistic goal for the majority of children and adolescents with T2DM. Considering that non-realistic goals may lead to failure [13-15], one of the first objectives should be to stabilize the weight during growth in order to standardize the BMI at long term while ensuring growth and normal development. With the aim of reducing obesity and all its physical and psychosocial consequences, intervention with young and his family should first be the acquisition of healthy diet, regular practice of physical activities and the reduction of sedentary behaviour [13-15].

For many patients, it is preferable to start by reducing sedentary behaviours, and gradually add regular physical activity to promote fitness and well-being, without seeking only to burn calories. Reducing the bad eating and physical activity habits and work to improve the good ones is just as important. These approaches used alone or in combination will contribute to the acquisition of a healthy lifestyle and weight control in the short and long term. The success of the intervention, which is different for each individual, requires realistic and sustainable treatment strategies. It can be defined as a better quality of life, a greater self-esteem, a greater body image, higher energy levels and others [13-15]. For some patients, the prevention or slowing of weight gain may be the only realistic goal. On the other hand, the resumption of weight should not be regarded as a failure; it is rather a natural and expected consequence of a chronic health problem [13-15]. To ensure proper tracking, child and parents have interest to keep a copy of the objectives to be achieved. Finally, in the treatment of patient with T2DM, your chance of success will be considerably better if you could get a mutual agreement on a glucose target and on realistic weight loss goals.

Assist

It is important to assist patients and parents in their goals towards good management of T2DM and obesity of their child, because they have many obstacles to overcome, such as stress, lack of time, fear to be blamed, little or no access to recreational facilities and socio-economic factors [13-15]. To help them we need to transmit documentation adapted to the patient, to their interests and to the needs of the family. For example, you can provide them with a detailed diet model, respecting the dietary recommendations based on the energy needs of the child as well as an array of energy expenditure by physical activity based on the weight of the child, the intensity and the duration of physical activity such as the documents provided by the Canadian Society for Exercise Physiology (www.csep.ca).

Assist means also to help the child, and his entire family develop healthier habits, better ways of promoting the weight maintenance and glycemic control, such as daily weighing, glucose monitoring and the definition of realistic objectives, and to identify stimuli that may influence the success of interventions including people, situations, emotions that trigger eating unhealthy and those limiting physical activity in order to change them.

According to the American Association of Diabetes Educators (https://www.diabeteseducator.org/), there are many steps to educating those with T2DM. The main step is healthy eating as mentioned above, followed by being active. We should teach the patient and his family members different ways to incorporate exercise into their lifestyle such as going on family walk, taking more family outings that gets the family out of the home for hiking, walking, biking, swimming and others that are inexpensive alternatives to watching television. We should then teach the patient and his family about monitoring and taking medication. This would have to be under the supervision of the parents. Monitoring would include how to use a blood sugar glucose meter, knowing when to check the numbers and the meanings of these numbers, the target range, and how to record blood sugar levels. Monitoring should also include how to keep the patient’s food and physical activity journal especially at school. Any medications prescribed by the physician should also be monitored. I would stress the importance to patient and his parents how important it is to follow the regimen prescribed by the HCP. As discussed in the next section, to ensure that all the patient is adequately educate about all the aspects of his disease, you will arrange for him and his family to be seen by a T2DM specialized nurse.

The next step is problem solving which looks at situations in which the patient may struggle to stick to her new, healthy lifestyle. It consists of seven steps: 1) definition of the problem as accurately as possible; [2] clarification of the problem by putting it in its context (reformulate the problem can help in its clarification]; [3] collection of the greatest number of solutions [brainstorming]; [4] analysis of the impact of each proposed solution [weigh the pros and cons of each of the solutions]; [5] selecting the best solution or combination of solutions; [6] implementation of the selected solution [define the stages of implementation of this solution]; [7] evaluation of results and corrections of the different stages if necessary [13-15].

By using this approach to each problem experienced by the patient and his family, they become, with a little practice, more autonomous in the management of the problems affecting their T2DM and weight management goals [13-15]. Meetings with the child and his parents, it is also very important to find, or at least provide appropriate suggestions to address personal and family barriers as well as to assist in the development of the skills of family organization promoting the achievement of adequate behaviours. Finally, it is important to plan for the unexpected and relapses by providing information and resources [13-15]. If necessary, a psychology or psychiatry consultation may be necessary to help the patient to understand and solve psychological problems such as esteem self-esteem, body image, acceptance or depression problems related to the condition of the child [13-15]. All of these steps would not be included in one session as that is a lot to take in but handouts are available on the American Association of Diabetes Educators website. Also, I would talk with the patient and his family about enrolling in a diabetes camp in order to meet other kids in similar situations and hopefully help ease the adjustments into this new lifestyle, while finding support [13-15].

Education around lifestyle modification involves not just the child but also his/her family. The whole family may need education to understand the principles of treatment for T2DM and the critical importance of lifestyle changes if chronic complications are to be prevented. The whole family should be encouraged to change their diet consistent with healthy eating recommendations, including individualized counselling for weight reduction, reduced total and saturated fat intake and increased fibre intake [13-15]. The key areas that have been found important in children include elimination of sugar-containing soft drinks and juice; taking meals on schedule and in one place, with no other activity at the same time such as watching TV, and ideally as a family group; portion control by reducing portion sizes; and limiting high fat, high calorie density food in the home [13-15].

Exercise management means developing individual exercise programs that are enjoyable, affordable for the family, and participated in by at least one other family member. Families should be encouraged to develop an achievable daily exercise program, including reducing sedentary time. Opportunities may include using stairs instead of elevators; walking part of the way to school; using an exercise machine at home, or exercise DVDs; and walking with a family member after school [13-15].

Assist aims to intervene on the perception of children and parents, and to raise awareness of the predisposition to gain weight, the severity of the problem of weight and the benefits of treatment on health and quality of life [13-15]. Assist aims to discuss about self-esteem, body image and to learn how to decode the emotions that often push the kids to eat well beyond their needs. Assist is intended to help in the development of communication with the patient and in the development of parental skills as well as to increase knowledge about the regulation of body weight and in the control of glucose levels. Assist aims to understand what a healthy diet is and why it is necessary to increase physical activity and reduce sedentary behaviors to help in the management of T2DM. Assist aims to provide information on the ways to modify certain negative behaviours related to a mismanagement of body weight and glucose control. An essential aspect of the assist part of the “6As” model of counselling is to teach the patient and his parent how to establish appropriate goals in terms of weight loss, nutrition and physical activity and glucose targets [13- 15]. Finally, the following simple slogan to promote a healthy lifestyle among youth and their families: “5, 3, 2, 1, 0”, designating five [5] portions and more of fruits and vegetables per day, three [3] structured meals per day [including breakfast], two [2] hours or less of television or video games per day an [1] hour or more of moderate to vigorous physical activity daily and no [10] sugary drink is certainly a good toll to assist T2DM pediatric patients achieving their treatment goals.

Arrange

Scientific evidences support the need for a multidisciplinary approach in the management of T2DM pediatric patients [13- 15]. They also confirm that a follow up with the family doctor, pediatrician and other HPC is essential to the acquisition and maintenance of glucose targets, weight loss goals and healthy habits [13-15]. This follow-up must be arranged with the patients and their parents, especially when other HPC or specialists are concerned, because in some cases, this can lead to unexpected financial expenses [13-15]. This monitoring can cause different emotions, especially when a medical specialist should be consulted. Given the chronic nature of T2DM, a long-term monitoring is essential, the “arrange” component of the “6As” model of counselling becomes an integral part in the monitoring of T2DM in pediatric patients. The frequency of meetings may vary depending on the patient and the treatment objectives [case by case] and must also be decided and discussed with parents, because this follow-up requires certain family organizations. The success of the treatment is directly related to the frequency of contacts, while the lack of follow-up or interventions can certainly lead to failure [13-15]. Arrange for follow-up may take the form of a brief phone call, from an email or a texto, or the use of a web applications or a return to the clinic, as needed.

Monitoring is essential to quickly identify any problematic situation, social or psychological aspects related to wrong eating or physical activity habits, which have repercussions and are responsible for failures to treatment. At meetings, it is important to discuss with the parents and the patient of what worked or not, to encourage behaviour which have been successful, in order to find solutions to improve or correct behaviour with little success and, above all, to support the family in its efforts, while establishing a good relationship with them to promote their returns if and keep them motivated and to provide additional support as needed [13-15].

The patient and his family should be educated on self-monitoring of blood glucose (SMBG). It is important to teach both the patient and his parents because the child are often too young and may need assistance until they get used to the system. SMBG is recommended with individuals with T2DM because it has been found to be very effective in controlling blood glucose levels. And for that you will need to arrange that the patient and his family be seen by a specialized diabetes nurse. Once T2DM is diagnosed, the patient will need to be followed regularly for early detection of complications. Once glycaemic goals have been met, the frequency of monitoring may be reduced to 2 to 3 fasting and 2 to 3 postprandial capillary checks per week. Clearly, children on insulin therapy should be undertaking more frequent testing. HbA1c should be assessed every 3 months if on insulin treatment.

Conclusion

HCP are in a very good position for supporting appropriate efficient intervention for the treatment of T2DM in pediatric patients. The reasons why the approach discussed above has more chance of success is that the work of behavior change is not taken on solely by the HCP. The main role for the HCP is to start sensitive conversations, achieve agreement on following through with effective treatment strategies, and support the patient in the initiatives that he or she undertakes. The 6As model of counselling comprises a manageable evidence-based behavioral intervention strategy that has the potential to improve the success of T2DM management with T2DM pediatric patients within primary care as this approach as already being successful for other metabolic disorders including pediatric obesity [13-15].

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  • Nadler EP, Reddy S, Isenalumhe A, et al. (2009) Laparoscopic adjustable gastric banding for morbidly obese adolescence affects android fat loss, resolution comorbidities, and improved metabolic status. J Am Coll Surg 209:638–644.
  • O’Brien PE, Sawyer SM, Laurie C, Brown WA, Skinner S, et al. (2010) Laparoscopic adjustable gastric banding in severely obese adolescents: a randomized trial. JAMA 303: 519-526. [crossref]

Development Process for Drugs for Pediatric Patients Suffering from T2DM

Introduction

Despite the large increase in the number of cases of T2DM in children and adolescents over the last 15 to 20 years, this metabolic disorder remains relatively rare. The National Institutes of Health (NIH) estimates that there are around 40,000–50,000 children and adolescents with T2DM in the US currently [1]. A number that is far lower than the maximum number of 200,000 to be considered an orphan disease by the US FDA (http://www.fda.gov/ForIndustry/ DevelopingProductsforRareDiseasesConditions/ucm2005525.htm). This number is also a lot lesser compared to the more than 18 million adults with T2DM in the US. Furthermore, the annual incidence of T2DM in children and adolescent has been estimated by the SEARCH for Diabetes in Youth Study to be approximately 3700 in the US but not much as 5000 new cases per year [2].

Nonetheless, these numbers are still much less than the estimate of 15,000 new cases of childhood T1DM or the more than 1 million new cases of T2DM among adults each year [3]. Unlike in the adult population, undiagnosed T2DM is rare in high-risk obese adolescents [4], with less than 0.5 % of at-risk obese minority of children and adolescents being identified with T2DM via screening of FPG, OGTT, or HbA1c. Therefore, almost all children/adolescents with T2DM are identified clinically, and the registry-based estimates of diagnosed cases of T2DM in the US and Canada most likely reflect the total number of individuals under 18 years-old with the disease. Thus, potential clinical trials are very limited as they begin with a small pool from which to draw participants [5]. In the following article, we will discuss the factors that further limit eligibility of clinical trial participants as well as possible solutions to overcome these limitations.

Barriers to clinical trial participation

Pediatric T2DM represents a disorder with substantial risk for long-term metabolic, CVD, and renal morbidity and mortality. It is also an important individual and societal burden. Growing literature suggests that the disorder may have unique biological features, including accelerated loss of β-cell function relative to adults with T2DM, as well as a high risk of development of micro-and macrovascular complications. However, despite the availability of many novel oral anti-diabetic drugs (OADs) for the treatment of T2DM in adults, little information is available regarding the efficacy and safety of these OADs in the pediatric population [5]. Few results from pediatric studies have been reported, and approved treatment options remain limited to metformin and insulin. Furthermore, the results of the TODAY study demonstrated a high level of treatment failure with the use of metformin alone or in combination with LSI. Similarly, with the development of T2DM patients may have to switch or add other OADs to the initial regimen to better control their T2DM. Therefore, there is a high need in pediatric patients suffering from T2DM to have access to new OADs with higher efficacy and safety. A number of demographic, economic, and social challenges have limited the recruitment and the retention in pediatric T2DM clinical trials [5]. In the following sections we will discussed some limitations that could have an impact on the eligibility for clinical trials of pediatric patients with T2DM.

Early initiation of therapy

Despite the rise in prevalence of T2DM among children and adolescents, T1DM still remains more common, and an adolescent presenting with new-onset diabetes is still more likely to have T1DM [3]. Considering that many pediatric patients with T1DM will also present with obesity it becomes very difficult to reliably distinguish individuals with T2DM on the clinical basis alone since most of the T2DM pediatric patients are also obese. Therefore, even among those children and adolescent at highest risk i.e., obese patients, certain minorities and those in the middle of their puberty, the possibility of T1DM is high enough that many clinicians will decide to initiate insulin therapy until the diagnosis has been formally determined through antibody testing [6]. In addition, in regular clinical practice, if there is any doubt about the diagnosis of T2DM, then it is much safer to commence insulin treatment and revise the diagnosis later in order to avoid possible metabolic decompensation. However, once insulin is initiated, a certain degree of glycemic control is often achieved which means that the individual no longer meets the HbA1c criteria for clinical trial participation. Furthermore, insulin is often used as glycemic treatment in clinical studies of OADs and previous exposure to insulin limits the interpretation of results. Thus, the pool of naïve patients eligible for clinical trials is small, and identifying such patients requires careful coordination among HCPs and the research teams [7-8].

Glycemic Control

Most newly diagnosed patients initially respond well to treatment, and measures of glycaemia, including FPG and HbA1c, rapidly decrease. For instance, in the TODAY study, 90 % of participants were able to achieve a median HbA1c of 5.9 % after a median of 10 weeks on metformin [9]. Therefore, individuals who have been treated for more than a few weeks may no longer be suitable for clinical trials, since the main primary study objectives generally call for enrollment of participants with limited exposure to insulin or metformin and with inadequate glycemic control at baseline in order to demonstrate efficacy through reductions in HbA1c. To complicate matters further, the withdrawal of insulin or metformin in stably treated patients in order for them to qualify for placebo-controlled clinical trials is not ethically acceptable in this vulnerable population. Thus, randomised clinical trials with new OAD for the treatment of pediatric patients with T2DM are limited to the small pool of potential participants consisting of patients identified before treatment is initiated, including patients responding poorly to treatment, or those in whom insulin or metformin is discontinued on clinical grounds but who maintain HbA1c within the inclusion range after discontinuation [5].

Inclusion and exclusion criteria

Common additional inclusion/exclusion criteria further limit the number of eligible patients. For instance, there is a high prevalence of NAFLD in children and adolescents with T2DM [10], with up to one third having ALT values greater than three times the upper limit of normal. This is representative of common exclusion criteria in clinical trials of OADs [5]. In several studies of adolescents with T2DM a large percentage of screened patients do not meet eligibility criteria due to the high prevalence of obesity-related comorbidities, such as HTN, hyperlipidemia, menstrual irregularities, and obstructive sleep apnea, which result in failure to most patients to meet the minimal inclusion and/or exclusion criteria. In addition, exposure to atypical antipsychotics or oral corticosteroids for asthma is prevalent in this population of T2DM and both are often exclusions for study participation due to the potential diabetogenic properties of these compounds [11]. The combination of the upper age limit of 17 for pediatric studies and the median age at diagnosis of 14 means that the average duration of potential eligibility for a pediatric T2DM study is only 3–5 years [12]. Considering, all these exclusion criteria, the pool of candidate for clinical trial in pediatric T2DM is rather small [5]. Therefore, there is a need to find solution to overcome these barriers in order to be able to develop new OAD molecules for the unmet of this population of pediatric patients.

Loss of Compliance

The investigators of the TODAY trial reported that it was difficult to recruit patients with T2DM for duration beyond 6 months [12], as patients on oral therapy alone often begin to routinely miss clinic appointments for their diabetes care. This suggests that beyond the initial few months after diagnosis, enthusiasm of patients to participate in clinical trials, or to receive clinical care for their T2DM, decreases. Secondly, the mean HbA1c of 3 months prior to loss of glycemic control in TODAY study was 6.8 % suggesting that loss of glycemic control in children and adolescents with T2DM is significant and the time during which individuals on oral monotherapy will remain in the HbA1c window for inclusion into a clinical trial will be limited. Thirdly, TODAY results indicate that patients who fail metformin monotherapy have lower β-cell function than other individuals, thus, may be different from those responding to metformin monotherapy, potentially limiting the generalizability of a trial including too many of these patients [13-14]. Finally, given the potential for rapid metabolic deterioration of individuals failing metformin monotherapy, clinicians and investigators are cautious about enrolling such children and adolescents in placebo-controlled trials and will rather opt to initiate insulin therapy rapidly [5]. Adolescents as a group are generally less adherent than younger pediatric and adult cohorts to oral treatment regimens and study visits. Self-reported reasons for non-compliance included: forgetfulness, jobs busy schedules, less developed concepts of illness, less perceived vulnerability, higher levels of denial, and less cohesive future orientation [5]. Many adolescents may also leave home to attend college or live independently while others may have parents who are absent or poorly concerned about their child’s condition [5]. Patients report that major facilitators to research participation are positive peer and family influences, program incentives including money and school credit, spending time with friends, commitment, and personal gain.

Socioeconomic Challenges

The enrolment of potential study participants into any clinical trial requires a thorough understanding of the basic demographic characteristics of potential subjects [15]. Children and adolescents in the US with T2DM are obese; two thirds are female and are almost always pubertal. They are socio-economically disadvantaged i.e., 41.5 % are from a household having a total annual income of <$25,000; they are predominantly living in a single-parent home, and they are overrepresented in most ethnic minority groups [5]. They are poorly educated i.e., their highest level of education attained by a parent/ guardian in the household is less than a high school graduate in 26.3 %, and they are almost all have a strong family history of T2DM. In Europe, most of the reported cases have been among immigrant groups in the UK and Germany [17]. In China and in India, like in the USA, most new cases were in individuals who were pubertal and obese i.e., with a BMI above the 95th percentile [17-18]. Overall, these characteristics present particular challenges in designing and implementing clinical trials for pediatric patients with T2DM. There are other barriers inherent to the adolescent population, including changing housing and unstable home environments, unreliable transportation for travel to and from appointments, difficult communication between participant and research team because of suboptimal parental support for research participation, high rates of missed medical visits, poor adherence to medical therapy in part due to large financial burdens related to the costs of present-day diabetes care, and others [19].

Sponsor and Regulatory Challenges

In Canada, to have a medication authorised and marketed, pharmaceutical companies have the obligations to systematically demonstrate the safety and efficacy of their products and the risk/ benefice ratio should be favorable. Pediatric patients should be given medicines that have been appropriately evaluated for their use. Their product should be safe and effective for pediatric patients and their approval requires the timely development of information on the proper use of medicinal products in pediatric patients of various ages and, often, the development of pediatric formulations of those products [5]. Obtaining knowledge of the effects of medicinal products in the pediatric patients is an important goal. However, this should be done without compromising the well-being of pediatric patients participating in clinical studies [5]. This responsibility is shared by companies, regulatory authorities, health professionals, and society as a whole (http://www.hc-sc.gc.ca/dhp-mps/alt_formats/hpfb-dgpsa/ pdf/prodpharma/e11-eng.pdf).

In USA, the establishment of the Pediatric Review Committee (PeRC) under the Pediatric Research Equity Act (PREA) and the FDA Amendment Act in 2007 further permitted the FDA to specifically require assessment of the safety and effectiveness of a product in pediatric patients in all applications for new active ingredients, new indications, new dosage forms, new dosing regimens, or new routes of administration unless this requirement is waived, deferred, or inapplicable [5, 20-22]. PeRC reviews the requested pediatric plans and provides assessment and recommendations to FDA as a part of the New Drug Application (NDA) approval process and reviews all requests for deferral and waiver. In general, deferral is granted so that the approval for use in the adult population is not delayed.

In Europe, similar regulations have been established to govern requirement for pediatric investigation during the drug approval process by the Pediatric Committee of the European Medicines Agency (EMA) [23-24]. Despite the incentive of patent exclusivity or the statutory requirement from the EMA, it has remained challenging to initiate, conduct, and complete studies in the pediatric T2DM population for the reasons discussed above [5]. In addition, from the sponsor point of view, clinical research in the pediatric population has other barriers to overcome including the lack of financial incentive to conduct clinical trials in T2DM pediatric populations considering the limited market and the recruitment difficulties [5]. In the past few years, a number of new OADs with novel mechanism of action have emerged, and many studies in the pediatric T2DM population have been required by the FDA, the EMA and Health Canada. The success of novel OAD development has inadvertently made the challenges of conducting pediatric T2DM studies even more difficult because of the continually increasing competition for the limited number of eligible study patients. Currently, clinical safety and efficacy studies and PK studies for DPP-4 inhibitors and insulin Determir have been completed within the last 2 years. However, clinical trials for GLP-1 analogues, SGLT2 inhibitors, insulin glargine, and others, seeking to randomize a total of over 1000 new study subjects remind us that recruitment issues remain a limiting factor in pediatric T2DM drug development [25].

To make the situation worse, more clinical safety and efficacy studies have already been committed to as a condition of new drug approval and will need to be initiated in the near future, and more studies will be required for applications that are either under regulatory review or to be submitted in the near future. These pediatric studies will evaluate not only novel active ingredients but also new dosage forms and dosing regimens including extended-release formulations, oral suspension, and fixed-dose combination of approved agents.

Unfortunately, new OAD development against pediatric T2DM seems to be a necessity since data from the TODAY study suggests that metformin monotherapy failure rates to be higher in children than adult population [26].

However, there are potentials solutions to overcome these barriers and in the following paragraphs some of these solutions will be briefly discussed.

Possible Solutions

What can be done to improve clinical research in pediatric T2DM patients so as to provide meaningful clinical trial data to inform treatment decisions? To reduce the burden on performing clinical trials with the very limited patient pool, it would be useful to consider the patients’ and the HCPs’ point of view in setting the priorities for clinical research in pediatric T2DM. From this perspective, it can be argued that it is more logical to selectively assess the most promising OADs and treatment regimens, instead of testing each new OAD and having them evaluated and authorised by regulatory agencies [5].

Create a Consortium

One interesting approach is to create a consortium of clinical research experts, together with other key stakeholders, to identify and prioritize the development of OADs and strategies needed to improve T2DM management in pediatric patients. The Drug Safety and Efficacy Network (DSEN) is an example of such a consortium which works in collaboration with the Canadian Institute of Health Research (CIHR) and many other stakeholders to identify appropriate therapy for patients who have already failed initial treatment. They work to identify and prioritize the clinical trial hypotheses, to determine the most promising OADs to be tested, and to design and conduct the clinical studies, utilizing a network of clinical trial sites representing centers most commonly tertiary hospital centers with clinical and research expertise in pediatric T2DM to undertake and perform the designed trials. This consortium and others require collaboration rather than competition between the HCPs, the clinical research experts, the medical societies, the pharmaceutical sponsors, the regulatory agencies, and the patient group representatives [26].

Adaptive design

Over the past few years, the use of adaptive designs in clinical research and in drug development based on accumulated data has become very popular because of its flexibility and its efficacy [27]. Based on the adaptations applied to the initial clinical trial during the drug development, this can lead to a reduction in the duration and the number of patients in the adaptive study and indirectly limit the exposure of patients to ineffective placebo or active comparators with less efficacy and known adverse drug reactions. A study performed by Spann et al. demonstrated, using an adaptive design, the same conclusion regarding the effectiveness of a treatment by using 50% fewer patients when compared to the initial trial. The number of patients had been reduced from 311 to 156; exposure to the placebo was reduced from 54 to 30 and exposure to the active comparator, with known side effects, was reduced from 126 to 60, compared to what was initially planned [28]. However, it must be ensured that the actual population of patients after the modifications does not deviate from the initial patient population, therefore avoiding a type I error i.e., to affirm the effectiveness of a drug by mistake while it is not effective, thus decreasing the possibility of arriving at inadequate conclusions or results difficult to interpret [29-30].

In addition, important adaptations to clinical trials and/or statistical procedures during development can make these clinical trials totally different from those initially designed and therefore these changes render us unable to adequately answer the scientific or medical issues raised initially. Traditionally, the clinical trial protocol must be carefully planned a priori and all clinical aspects related to this new protocol must be clearly documented and must comply with the requirements for clinical trials. Any significant changes in the design of the protocol, once started, must be authorized by a regulatory agency. In addition, changes made to the initial statistical procedures must be approved before their implementation, because these changes may represent a potential risk of bias, thus compromising the results of the clinical trial. In conclusion, the adaptive study plans allow a study protocol to be modified from its initial version based on new data from external sources or from an interim analysis of the data obtained from the ongoing clinical trial. However, any changes to the design or analysis of data from the study must be planned in advance and the situations where these changes will be introduced should also be previously specified.

While increased efficiency is an important goal in the development of drugs, this should not compromise the safety of the participants in clinical trials. The FDA says in its Guidance Document (www.fda. gov/downloads/Drugs/…/Guidances/ucm201790.pdf) that adaptive clinical trials may be suitable for the products with prior experience of known security or for products with adverse events with known pathophysiological mechanisms. The use of adaptive designs can certainly contribute to shortening the drug development timeframe by allowing the initiation of larger trials (Phase III) before smaller studies (Phase II) are fully completed and analyzed. However, the identification of adverse reactions may be inappropriately missed due to a reduced number of exposed patients combined with a reduction in duration of drug exposure. With this approach, the side effects associated with new drugs occurring in the long term can pass unnoticed, placing pressure on the is sufficiently similar between adults and children; 2) the response to treatment is sufficiently similar between adults and children; and 3) adults and children have a sufficiently similar exposure-response relationship. Considering that the drugs that require development in the pediatric population suffering from T2DM are mainly required in adolescents (mean age of 14) and that the response to treatment and the adverse drug reactions we are following are mainly the same as in adults, we can conclude that we meet the criteria for extrapolation from adult studies according to the FDA regulations. If needed, PK data to allow for the determination of an appropriate pediatric dosage and additional pediatric safety information can also be submitted using the 14 and above year-old group as mentioned above. development of prevention activities in post-approval phase.

Extrapolation from adult studies

The FDA has put in place the following rule that could be beneficial for the development of new drug that could also be applicable in pediatric patients suffering from T2DM. “Where the course of the disease and the effects of the drug are sufficiently similar in adults and pediatric patients, FDA may conclude that pediatric effectiveness can be extrapolated from adequate and well-controlled studies in adults usually supplemented with other information obtained in pediatric patients, such as PK studies. Studies may not be needed in each pediatric age group, if data from one age group can be extrapolated to another.” [21 CFR 314.55(a); 21 CFR 601.27(a)]. This extrapolation is based on three evidence-based assumptions as follows: 1) the course of the disease is sufficiently similar between adults and children; 2) the response to treatment is sufficiently similar between adults and children; and 3) adults and children have a sufficiently similar exposure-response relationship. Considering that the drugs that require development in the pediatric population suffering from T2DM are mainly required in adolescents (mean age of 14) and that the response to treatment and the adverse drug reactions we are following are mainly the same as in adults, we can conclude that we meet the criteria for extrapolation from adult studies according to the FDA regulations. If needed, PK data to allow for the determination of an appropriate pediatric dosage and additional pediatric safety information can also be submitted using the 14 and above year-old group as mentioned above.

Health Canada has also put in place the following rule regarding the extrapolation from adult studies: When a medicinal product is to be used in the pediatric population for the same indication(s) as those studied and approved in adults, the disease process is similar in adults and pediatric patients, and the outcome of therapy is likely to be comparable, extrapolation from adult efficacy data may be appropriate. In such cases, pharmacokinetic studies in all the age ranges of pediatric patients likely to receive the medicinal product, together with safety studies, may provide adequate information for use by allowing selection of pediatric doses that will produce blood levels similar to those observed in adults. If this approach is taken, adult pharmacokinetic data should be available to plan the pediatric studies as discussed above (http:// www.hc-sc.gc.ca/dhp-mps/alt_formats/hpfb-dgpsa/pdf/prodpharma/ e11-eng.pdf) .

Clinical trials combining adult and pediatric patients

Another interesting approach is to include a subgroup of pediatric patients within the adult’s clinical trials and perform the statistical analysis by subgroup based on the age of patients. Considering, that the mean age that the pediatric patients that develops T2DM is around the mid-puberty, which is around 14 years-old, therefore, having a subgroup aged 13-17 years-old would be acceptable where compared to control group of the same age similar weight or body surface area. Obviously consideration should be given to extrapolation from adult studies as mentioned above. It is not the purpose of this paragraph to discuss the design and the statistical methods used for this combine clinical trial. Briefly, these clinical trials should follow the ICH-E6 Guideline for Good Clinical Practice (http://www.ich.org/fileadmin/Public_ Web_Site/ICH_Products/Guidelines/Efficacy/E6/E6_R1_Guideline. pdf), the ICH-E9 on Statistical Principles for Clinical Trials (http:// www.ich.org/fileadmin/Public_Web_Site/ICH_Products/Guidelines/ Efficacy/E9/Step4/E9_Guideline.pdf) and must be authorised on a case by case basis by a regulatory agency such as the FDA, the EMA or Health Canada.

Conclusions

Pediatric T2DM represents an emerging disorder with substantial risk for long-term metabolic complications, CVD, and renal morbidity and mortality, as well as individual and societal burden. A number of demographic, economic, and social barriers limit the recruitment and the retention of patients in pediatric T2DM clinical trials resulting in limited studies with limited population. We have also discussed a certain number of potential solutions to overcome these barriers. These solutions could facilitate timely completion of the required clinical trials sponsored by pharmaceutical companies, and acknowledge the mandate of regulatory agencies to ensure the availability of safe and well-studied OADs for affected pediatric patients with T2DM. If successful, these potential solutions could also serve as a model for clinical trials in other rare and understudied pediatric disorders.
How might we improve recruitment and retention of pediatric patients in clinical trials? Studies outside the field of pediatric T2DM offer some promising strategies. Villarruel et al. [31] showed that a combination of incentives including money and school credit for participation, flexible program start times, continued contact with project staff including more frequent reminders, increasing the interactive components of follow-up, and recognizing the importance of potential mobility limitations among adolescents and their families contributed to a reduction in risky sexual behavior in Latino youth. Finally, we suggest that more should be done to find young patients in the places where they are most comfortable i.e., at their local clinics, in their neighborhoods, and at their schools. Rather than asking patients to come to us, perhaps we should consider that we, as HCPs and research investigators, go to them [32].

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An Adolescent with Obesity that presents with Symptoms of T2DM

Case Report

1. You see a girl (Janet) of 14 years-old with her father in your office for a sore throat that you manage with success. Looking at this girl, you notice that she is obese and that no recent measurement of Body Mass Index (BMI) is included in her file. What should you do as a first step since the main issue at this time is her weight problem?

(a) you ignore the weight problem and discuss only the medical consequences associated with obesity.

(b) you measure her BMI.

(c) you arrange a follow-up with a dietitian for a weight loss program.

(d) you ask permission to discuss with the children and parents of the child’s weight problem and explore changes skills.

Answer: d

Explanations

(a) You ignore the weight problem and discuss only the medical consequences associated with obesity

HCPs can play an important role in the prevention and management of pediatric obesity, because they have long-term relations with obese children/adolescent and their parents. However, most primary HCPs feel ill-prepared to deal with this problem or even they perceive their efforts as inefficient [1]. They also noted obstacles to the proper management of pediatric obesity such as attitude and beliefs perceived by the children/adolescent and their parents, their own attitudes and beliefs concerning the problem of pediatric obesity as well as obstacles related to the clinical practice with this population (lack of time and motivation, inadequate medical equipment, etc.). Even considering these obstacles, ignoring the problem is certainly not the best approach, and it is contrary to what it is recommended in the prevention practice guidelines [2-4].

HCPs often associate obesity with their related medical consequences such as T2DM, HTN, dyslipidemia, CVD, orthopedic and other health problems. Those are certainly very good issues that need to be investigated. However, as a suggested approach since this patient is presenting without any other complaints, it is essential to determine the level of awareness of the children/adolescent and parents to the problem of the child’s weight and then to evaluate their ability to make one or more changes to improve or fix this problem. This process cannot be done without first asking for the permission to discuss the problem with the youth and her parents until you find other obesity-related problems. The best way to approach this patient and her father is by utilising the first A “Ask” of the “6As” model of counselling. For more information on the counselling approach of an obese patient the reader is refer to the “6As” model that is fully described in the article number 4, especially on the “ask” component of the model. The readers are also invited to read the most recent publications and books made by Dr Plourde on this counselling approach to have a complete explanation on the use of this counselling technique [5-8].

(b) You measure her BMI

The measurement of BMI is recommended as a practical measure for the prevention and management of pediatric obesity. It must be taken each year from the age of 2 years to follow the change of child’s weight status and its associated disorders. It can be taken at each visit of regular monitoring or when the patient presents for a specific health problem, as for our patient. The BMI measurement is the method most commonly accepted and used to track obesity in children and adolescent because it is a non-invasive measure. It is also a reliable indicator of body fat and correlates well with the complications associated with obesity [2-4]. Although it is recommended to perform the measurement of BMI in this young girl to evaluate her obesity and health risks, considering that this patient is obese, measuring her BMI is certainly relevant but first you should ask for the permission to discuss the weight problem and raise this issue with tact to avoid creating potential discomfort with the patient and her father. Overweight and obesity highly increase the risk of developing T2DM during childhood. There is also strong evidence that those who are obese during childhood are highly likely to be obese into adulthood and presents the obesity-associated complications [9].

(c) You arrange a follow-up with a dietitian for a weight loss program

This is certainly an approach that we should look after a discussion with the patient and her father and a more thorough assessment of her condition. Still, this shouldn’t be the first step. Weight loss is not generally recommended for children who are overweight as it may interfere with growth and development [5-8]. The main goal here is to keep Janet from gaining additional weight with hopes that she will grow into her current weight. With healthy eating habits and incorporating exercise, the emphasis should be on Janet’s new healthy lifestyle. Once she is finished growing, if weight loss is a concern, it can then be implemented. But, at this time, the priority is to ask her the permission to discuss her weight problem with her and her father. For more information on what should be included in this step of the counselling please refer to section “Arrange” component of the “6As” model of counselling.

(d) You ask permission to discuss with the children and parents of the child’s weight problem and explore changes skills

The first step and the most important in this case since you note that this patient is obese, is to ask the permission to discuss the problem of weight with the child and her father by asking the following questions or similar questions: “Are you concerned about your child’s weight and the effects of her weight on her health or quality of life? ‘’ Then you suggest the following statement: “Can we have a discussion about the problem of your child’s weight.” These questions can be modified to be adapted to the age and condition of the child [5-8].

The weight problem of a child is a sensitive issue that could embarrass the child and the parents. Therefore, you should proceed without issuing judgment. It is important not to blame or cause feelings of guilt among them. We must limit the medical jargon and use a sensitive and respectful approach. These discussions may provide to family physicians, pediatricians and other HCPs, as well as parents, better identification of personal or family environment factors which act as barriers to change. Talking about the advantages and disadvantages of modifications to the current behaviors can also help parents to reconsider what they can do to help their child [5-8].

2. During the discussion you learned that the patient has non voluntary loss few kg during the past 5 weeks and had more urination than usual during the past 4 days. There was no history of polyphagia, polydipsia or dysuria. But she mentioned that she feels more tired recently that she attributed to her recent episode of sickness including sore throat, cough and some fever. You learned that her mother had gestational diabetes while she was pregnant with Janet. She is now known T2DM since 3 years ago and presently she is on OADs. Janet is the second of three children but her siblings are well. There is a positive family history of T2DM in mother, maternal grandmother, maternal grand aunt, paternal uncle and paternal grandmother. Findings on physical examination were those of an obese adolescent (BMI-32kg/m2) not dehydrated with no evidence of acanthosis nigricans. Systemic examination was essentially normal. The blood pressure was 124/82 which was essentially comparable on subsequent visit. The patient and his parents have a sedentary lifestyle with plenty of time spent in front of the television, playing video games and little or no regular physical activity. Their eating habits are also inadequate; they consume a lot of fatty foods and sugary drinks and junk food. There is also a poor intake of fruits and vegetables. Random blood sugar at presentation was 11.9 mmol/l (N= 3.9 – 5.5 mmol/l), and Urinalysis showed +1 of glucose and absent ketones. A provisional diagnosis of T2DM was made.

What should be the next most important step(s)?

(a) you explain that you will make a full assessment of the problem, including personal and family risk factors associated with her condition.

b) you give advice and information on diets, physical activity and other modes of treatment programs to help parents make an informed decision on the most appropriate method to manage the T2DM problem of their daughter.

(c) you enter into a mutual agreement on the management goals of the T2DM of their child.

(d) assist the child and parents to recognize factors that may resolve the obstacles in the management of the T2DM problem of the child.

(e) explain the necessary follow-up with you, family physician or pediatrician, or other HCPs, according to the needs.

Answer: a

Explanations

a) you explain that you will make a full assessment of the problem, including personal and family risk factors associated with her condition.

It is important to perform a complete history, a general physical examination and appropriate laboratory tests to exclude any complications associated with the adolescent condition to be consistent with the “assess” component of the “6As” model of counselling. The history of the development of the adolescent, including possible delays of growth and weight gain mode must also be evaluated. Psychosocial history of the adolescent looking for a history of depression, eating disorders and the quality of life is also useful because it may indicate the need for a consultation in psychology or psychiatry. The family history of T2DM and associated disorders, including a detailed history of risk factors and complications (see article number 2), must be an integral part of the medical history. The history is complemented by questioning past and present, use of drugs including drugs taken by the mother during pregnancy and lifestyle, physical activity, eating habits, sleep patterns, family dynamics and socio-economic and environmental stress. You complete your assessment by performing a physical examination followed by the laboratory tests recommended (see laboratory testing) and those relevant from the medical history and physical examination. For more information on what should be included in this step of the counselling please refer to the appropriate sections of article number 4.

b) you give advice and information on diets, physical activity and other modes of treatment programs to help parents make an informed decision on the most appropriate method to manage the T2DM problem of their daughter.

Pending the confirmation of the T2DM diagnosis by the full assessment (item a), the patient and parents were counseled and placed on dietary control with elimination of SSBs such as juices, soda, reduction of foods with high glycemic index (GI) such as table sugar, ice cream, white bread etc. and increased intake of food with low GI such as pasta, skim milk, sweet potatoes, as well as reducing portion of food and increasing exercise as explained in question 1c. For more information on what should be included in the “Advice” component of the “6As” model of counselling.

As for our patient, the mean age at diagnosis reported for T2DM in youth is 14 years, coinciding with the relative insulin-resistance occurring during puberty, which may precipitate glucose intolerance [10-13]. Although adolescents presenting with diabetes are normally assumed to have T1DM, this may no longer be the case, even if the patient presents in ketoacidosis requiring insulin treatment. In recent studies 5 to 25% of children with T2DM presented with ketoacidosis, and ketonuria was present in a further 33%. The majority of these children are obese, but the severity of the obesity may be mitigated by weight loss prior to presentation [10-13]. These factors may lead to the misclassification of adolescents with T2DM as T1DM, and possibly an under estimation of the current prevalence of this clinical problem. Other pertinent features in the differential diagnosis include a positive family history; the frequency of a first degree relative with T2DM has been reported as ranging from 74 to100%, and the presence of acanthosis nigricans has always been regarded as rare in childhood but when present is strongly associated with obesity and insulin resistance [10-13].

The HCP should pay particular attention to the following points while in presence of an T2DM pediatric patient: 1). both environmental and genetic factors contribute to the etiology of T2DM; 2). a family history of T2DM indicates an increased risk for the disease; 3). the most important preventive measure for an at-risk individual is a healthy lifestyle, including regular exercise, weight management, and a diet low in fats and concentrated sugars and high in fruits and vegetables; 4). small proportion of diabetes mellitus is due to highly penetrant autosomal dominant mutations that result in maturity-onset diabetes of the young (MODY), a form of diabetes mellitus that resembles T2DM and 5). the lifetime risk of T2DM in the general population is about 5%. If a person has a biological relative with T2DM, the risk is increased. When a parent has T2DM, the lifetime risk for offspring is 10-15%. Risk is increased to a lesser degree if only a second-degree relative, such as an aunt, uncle, or grandparent, is affected [10-13].

In general the following are the red flags: i) obesity (as well as body fat distribution, especially central or abdominal body fat adiposity), lack of exercise, and poor dietary habits are all associated with increased risk for T2DM; ii). prevalence of T2DM is higher in some racial and ethnic groups, including African Americans, Native Americans, Hispanic Americans, Asian Americans, and Pacific Islanders; 3). early signs of T2DM include increased thirst, frequent urination, sudden weight loss, blurred vision, and fatigue or irritability as a result of changes in blood sugar levels; 4) history of gestational DM and a high birth weight, and impaired glucose metabolism [10-13].

(c) you enter into a mutual agreement on the management goals of the T2DM of their child.

It is essential to establish the objectives of treatment with the child and the parents. Well family doctors, pediatricians and other HCPs are best placed to determine the best course of action with regard to treatment but it is the patient and his/her parents who must do the work. However, currently, it is difficult to come to a mutual agreement without performing the complete assessment of Janet’s medical condition (item a). In the “mutual agreement” step of the “6As” model of counselling, you should gently mention that the long-term safety is a priority with children and adolescents diagnosed with T2DM and that achieving good glycemic control safely and without delay is a priority for newly diagnosed T2DM individuals [11]. As Janet is young preventing/delaying the onset of diabetes complications through getting optimal glycemic control is particularly important. In adolescents, the onset of T2DM points to a lot of potential complications if the disease is not adequately controlled for long periods of time [14]. An HbA1c as near to normal (< 7%) while minimizing the risk of hypoglycemia is appropriate [12, 15]. There is no need to be aggressive in selecting the general treatment target since Janet seems to have an appropriate family support and she seems highly collaborative; we can consider stronger treatment target if we have strong social and family support, absence of co-morbidities and complications and recent diagnosis [11], but this cannot be decided at this time since the full assessment (item a) of her condition has not been completed. The glycemic target should always be individualised based on a number of factors [11]. The American Diabetes Association has put in place a very nice graphical representation of individual physiologic and patient-centered aspects (https://durobojh7gocg. cloudfront.net/content/diacare/38/1/140/F1.large.jpg) that one should incorporate in the selection of our treatment target that we can then negotiate with the patient [5-8]. For more information on what should be included in this “mutual agreement” component of the “6As” model of counselling. You, Janet and the parents agree on a weight loss of approximately one pound per week for the next few weeks with diet and physical activity has this can have beneficial effects on improving her glycemic control as well as her lipid levels. You also agree on HbA1c (< 7%) glycemic target, but you postpone the final discussion until you complete the full assessment (item a) of her condition to rule out other co-morbidities and complications that could impact the glucose target [11].

(d) assist the child and parents to recognize factors that may re¬solve the obstacles in the management of the T2DM problem of the child.

Family physicians, pediatricians and other HCP must assist the child and parents overcome their barriers to weight and T2DM management as “assist” is another important component of the “6As” model of counseling. Patients and parents should be directed to resources promoting proper management of weight and T2DM. Assist means educate, recommend and support the child and his parents in the performing of their duties. Again a full assessment (item a) should be performed first in order to have a clear clinical picture of the clinical context.

Another approach that you can combine to the “assist” step is working on correcting negative health behaviors. Once families are ready to make a change, you can choose a behavior that children and parents want to change and for which they feel they can achieve successfully. A useful strategy is to help parents change the family environment to break the habit of the child to eat in an unhealthy way or stay sedentary. Parents can implement changes in the family environment so that healthy foods are more easily available and accessible than the unhealthy food which become less accessible and even absent from their environment.

Parents can also make it harder to access sedentary activities by removing the TV in the kitchen or in the bedroom of the child, to get rid of the remote control and put video games in a closet. They can make physical activity more accessible by playing with the children, by going to the park with them. These small changes in the family environment prevent known and unhealthy behaviors and promote the acquisition of new healthier habits. It is important to deliver this message to parents, because even a small change in behavior can make a big difference in the energy ingested or expanded and this can significantly improve the condition of the child [5-8].

(e) explain the necessary follow-up with you, family physician or pediatrician, or other HCPs, according to the needs.

Monitoring is essential to ensure that the medical recommendations can be met more easily. Family doctors, pediatricians and other HCP may need to negotiate with the child and parents the frequency of follow-ups, which will vary according to the condition of the child and the possibilities of family organization. If follow-up with other HCP is recommended, the relevance of this monitoring should be clearly explained to the parents and their agreement must be obtained before it is organized [5-8]. You will have to “arrange” for Janet and her family to be referred for a specialized diabetes nurses who will provide dietary and physical activity advices as well as teaching on self-monitoring of blood-glucose (SMBG), if the diagnosis of T2DM is confirmed after the complete assessment has been performed (item a). As mentioned, a provisional diagnosis of T2DM was made and a series of blood test was requested. For more information on what should be included in the “arrange” component of the “6As” model of counseling.

3. Two weeks after you received the following results. The fasting plasma glucose (FPG) was 12.8 mmol/L (N= 3.9-5.5 mmol/L); HbA1c was 10.2% (4-6%); Ketone body was absent; Tests for insulin antibody and antiglutamic acid decarboxylase (anti-GAD) were negative Cortisol level was normal with a value of 230.6nmol/l (240-418nmol/l), cholesterol level was elevated at 6.9mmol/l (<5.0mmol/l). The electrolyte results were within normal ranges with Sodium 137mmol/ l (128–142mmol/l), Potassium −4.4mmol/l (3.4–4.8 mmol/l), Bicarbonate − 25mmol/l (24–30 mmol/l), Urea−3.3 mmol/l (2.4–6.0mmol/l) and creatinine −75mmol/l (60–120mmol/l); C-Peptide 1.2 mmol/l (0.2-1.0mmoll); ACR 0.88 mg/mmol (<3.5 mg/mmol); eGFR 118 ml/min (90-120 ml/min). The definitive diagnosis was T2DM

What should be the next most important step(s)?

(a) you give advice and information on treatment options to help parents make an informed decision on the most appropriate option to manage the problem of their daughter.

(b) you enter into a mutual agreement on the management goals.

(c) help the child and parents to recognize the factors that can help resolve obstacles to T2DM management.

(d) explain the necessary follow-up with a nurse specialised in the treatment of T2DM.

(e) All of the above.

Answer: e

Explanations

(a) you give advice and information on treatment options to help parents make an informed decision on the most appropriate option to manage the problem of their daughter.

In the first follow-up discussion with Janet and her family you should explain the results that she obtained from the blood work (the chemical profile). You explain that based on the results, and the signs and symptoms she presented that she has T2DM. Because of her negative antibodies to GAD [15] and C-Peptide level we can exclude/confirm that she is not having T1DM. When we explained the laboratory results and discuss the diagnosis, we must limit the medical jargon and use a sensitive and respectful approach. You should explain that controlling her blood glucose is a priority for Janet, that the onset of T2DM at an early age point to a risk of multiple medical complications if the disease is not controlled for long periods [14]. However, because of her high C peptide concentration, this implies a certain degree of insulin resistance.

There are four different tests that can be used to diagnose T2DM. The first is the HbA1C test that is greater than 6.5% though there are some question as to how accurate these tests are as HbA1C levels might vary depending upon race/ethnicity. The second test that can permit a diagnosis is a FPG of greater than or equal to 7.0mmol/L. The third is of the two-hour plasma glucose or fasting glucose test which is a diagnosis if greater than or equal to 11.1 mmol/L during an OGTT. The last possible way to diagnose diabetes is by the symptoms – classic symptoms of hyperglycemia or hyperglycemic crisis which is random plasma glucose of greater than or equal to 11.1mmol/L. The standards for pre-diabetes are figured through similar tests but the numbers vary – these numbers are considered “normal but high” [10-13] The reason why Janet’s physician requested an autoantibody test as well as a C-peptide test is to ensure that the T2DM diagnosis is not being confused with T1DM. In obese children, screening guidelines for both T1DM and T2DM are very similar. C-peptide level is based on blood sugar level and is a sign that the body is producing insulin. A low levels or no insulin C-peptide means that the pancreas is producing little or no insulin. Janet’s C-peptide is high at 1.2 mmol/L while her GAD was negative. This means that Janet does in fact have T2DM and it is not being confused with T1DM. Because C-peptide level is high, this shows that her pancreas is still trying to overcompensate for the cells’ inability to take in glucose for energy.

Janet has cholesterol level of 12.8 mmol/L as mentioned earlier. This is high and due to her body’s inability to use blood glucose for energy and possibly a result of her high fat and high sugar diet, as well as her BMI of 31.0 kg/m². Her HbA1c level is an indication specifically of diabetes which was at an elevated level of 10.2% which is a measure of poor long-term blood glucose control. There was also protein and glucose in Janet’s urine which indicate that the kidney’s filtration ability has been altered.

In T1DM, there is a lack of insulin production caused by destruction of β-cells. In T2DM, insulin is produced but the tissues are insulin resistant and the body therefore has an increased need for insulin. To combat this, the pancreas produces more insulin but after too long the pancreas loses the ability to produce insulin at all. This result in T2DM which includes two metabolic defects: first insulin resistance and then insulin deficiency. Insulin resistance in T2DM is caused by a β-cell-receptor defect in which insulin cannot get into the cells and be taken up for fuel and then insulin deficiency which results in fasting hyperglycemia [10-13].

A pediatric patient with T2DM should be tested several times a year for protein in the urine. This is a sign that there is T2DM-related kidney damage as the kidney is allowing protein to escape the body without being absorbed. An extremely high amount of protein may be a sign of kidney disease. Kidney malfunctions and diabetes are related as kidneys are one of the organs that respond to the body’s glucose intolerance. Long-term glucose intolerance can harm the kidney, resulting with protein in the urine [10-13].

i) Potential Option: Lifestyle alone:

Achieving good glycemic control safely and without delay is a priority for newly diagnosed pediatric T2DM individuals [15]. As Janet is young preventing or delaying the onset of T2DM complications through optimal glycemic control is particularly important. In adolescents, the onset of T2DM points to a list of potential complications if the disease is uncontrolled for long periods of time [15]. Lifestyle interventions still form an integral part on any T2DM treatment regimen [15]. They can be considered in isolation for individuals with the glucose target of HbA1c (< 7.5%; 58 mmol/mol) [11]. Since Janet has marked hyperglycemia and even a strict diet and physical activity regimen is unlikely to restore her glycemic control, but would be certainly appropriate to correct her dyslipidemia.

ii) Potential Option selected: Lifestyle + metformin.

Metformin: Decrease HbA1c efficacy: high; hypoglycemic risk: low; Weight effect: Neutral/Loss; Major side effects: GI, Lactic acidosis; Cost: Low.

Choice of pharmacotherapy should aim to preserve β-cell function and improve insulin sensitivity; at present, metformin is the only OAD approved for use in children and adolescents [12, 15]. However Janet is severely hyperglycemic and metformin therapy alongside lifestyle interventions is unlikely to lower her HbA1c to the target level. Metformin would be expected to lower HbA1c by 1-2% leaving Janet with uncontrolled hyperglycemia [15].

iii) Potential Option: Lifestyle + Insulin .

Insulin: Decrease HbA1c efficacy: highest; hypoglycemic risk: high; Weight effect: Gain; Major side effects: hypoglycemia; Cost: variable.

Insulin can be considered alongside LSI from the onset for the treatment of T2DM in children and adolescents [11-12, 15]. For adolescents presenting with an HbA1c > 8% (69 mmol/mol) or severe manifestations of insulin deficiency, insulin is the most effective way to achieve rapid metabolic control [12]. However, Janet is nervous about the perspective of having to inject herself every day and is worried about weight gain since she is already obese. You should explain the benefits of using insulin to lower the risk of diabetes-related complications, that once glycemic control is obtained, it would likely be possible to switch to oral OAD (metformin) in combination with LSI.

(b) you enter into a mutual agreement on the management goals.

Following this discussion, the HCP and Janet decided upon a basal bolus of insulin regimen. Insulin regimens should mimic physiological insulin as closely as possible while achieving optimal glycemic control. Pre-prandial insulin should be divided into 3-4 pre-meal boluses; when regular insulin is being used, the basal: pre-prandial split is typically 30%:70% of the total daily insulin requirements For rapid acting pre-meal bolus, the basal pre-prandial split is typically 50%:50%. This is because regular insulin also provides some basal effects (10-15). The HCP and Janet decided to use rapid acting insulin for pre-meal boluses as it may reduce post prandial hyperglycemia and nocturnal hyperglycemia. Rapid acting insulin can also be taken immediately after food in order to increase flexibility.

During this short medical interview, you noted that one of the primary objectives of the child weight management is to improve her quality of life because she feels uncomfortable to play with the children of her age due to her weight. Therefore, she feels a bit excluded from her group. You also learned that neither the adolescent nor the parents are active physically. However, they do not seem to be very motivated by regular physical activity, despite the fact that this intervention could improve the skills of this young girl for the game and, therefore, have a positive effect on her quality of life. You agree, as a first step, to work on the reduction of sedentary behaviours such a reducing to less than 2 hours per day the time at watching TV or playing video games and gradually adding regular physical activity to promote physical fitness of this girl. You agree also on the importance to replace sedentary activities by low to moderate physical activities that parents and children would go to the convenience store, grocery store or another location nearby, foot or bike to increase in stages, physical activity, rather than taking the car [16].

(c) help the child and parents to recognize the factors that can help resolve obstacles to T2DM management.

Involving the entire family is important and ensures that the principle of treatment and the importance of LSI are clearly understood in order to permit appropriate level of support and encouragement from the entire family [13]. Education of the family and friends on the importance of lifestyle choices is essential [15]. Although Janet’s mother has T2DM, therapy is individualized and it is important that Janet’s family understands her individualized needs. In a family with more than one child, parental and sibling education may help prevent further development of T2DM in this family. Throughout the process, it is important to work with parents to verbalize clear and accessible objectives and discuss the steps to follow to achieve them. It is necessary to encourage parents to engage in healthy behaviours with the child/ adolescent and to serve as role models for change, an approach that has proved to be a good predictor of the success of the children in the management of their weight [5-8]. In this approach, the parents who eat vegetables, drink water instead of soft drinks, restrict the size of the portions of meals or snacks and engaged in physical activities with their children are more likely to encourage healthy behaviours in their children, because children learn by examples [5-8].

(d) explain the necessary follow-up with a nurse specialised in the treatment of T2DM.

You explain to the patient that insulin caries a risk of hypoglycemia and that SMBG is an integral part of optimizing Janet’s regimen. You explain that early optimization of blood glucose level will allow her for a rapid transition to oral therapy. For that Janet is advised to aim for the following blood glucose levels [13]: Pre-meal 5-7.2 mmol/L (90-130 mg/dL); Peak postprandial 10 mmol/L (180 mg/dL). You explain to Janet that in order to help her achieve these goals that you will refer her to a nurse specialized in the treatment of T2DM to learn about SMBG. The nurse will educate Janet on how to adjust insulin in response to daily glucose measurements and how to recognize and respond to hypoglycemia.

You explain that insulin is most effective when used in conjunction with an appropriate diet and exercise regimen to increase insulin sensitivity. For Janet the LSI must be specifically tailored to facilitate appropriate weight loss. In addition, to the advice on SMBG and the importance of adhering to the diet and exercise regimen, the diabetes nurses discuss the involvement of Janet’s family in the management of her diabetes. Janet and her family should be educated on SMBG – it is important to teach both Janet and her parents because Janet is young and may need assistance until she gets used to the system. SMBG is recommended with individuals with T2DM because it has been found to be very effective in controlling blood glucose levels. Tests should be done frequently in the beginning until patterns emerge and should be continued to be monitored around meal times, before and after physical activity, and before and after sleep. If Janet becomes ill then she must test her blood glucose every 4 to 6 hours with the same glucose targets as above.

According to the American Association of Diabetes Educators, there are many steps to educating those with diabetes. The first step is healthy eating as mentioned above, followed by being physically active. The nurse should teach Janet and her family members different ways to incorporate physical exercise into their daily routine such as going on family walk, taking more family outings that gets the family out of the home that are inexpensive alternatives to watching television (hiking, swimming, etc.). The nurse should then teach Janet and her family about monitoring and taking her insulin. This would have to be under the supervision of her parents as Janet is just 14 years old. Monitoring would include how to use a SBGM, knowing when to check the numbers and the meanings, the target range, and how to record blood sugar levels. This information should also be kept in Janet’s food journal especially at school. Any medications prescribed by Janet’s HCP should also be included. The nurse should stress the importance to Janet and her parents how important it is to follow this regimen. The next step is problem solving which looks at situations in which Janet may struggle to stick to her new, healthy lifestyle. For example, if there are no options at school for lunch that allow Janet to stick to her new diet or when she goes out with friends. The next step is healthy coping which is about adjustment to this new lifestyle, and the final step is about reducing risk which involves impaired awareness of warning signs of hypoglycemia [17]. For a complete example on problem solving, please consult the Chapter 7 of the book from Dr Plourde [5].

4. Then Janet has returned for her 6 month follow-up and since her diagnosis of T2DM, several insulin adjustments have been made to control her blood glucose level. Janet explain that she is feeling well but finds embarrassing to inject every day especially at school and when she goes out with friends. In addition she has managed very well to lose weight with good adherence to diet and exercise and she no longer feels exclude from the group. She expresses a strong desire to switch to oral therapy. You see that Janet’s journal on her cell phone has been meticulously completed and she has not experienced any problem with postprandial hyperglycemia in the past 3 months. Janet wants to transition from insulin to metformin. Her FPG: 6.7 mmol/L (120 mg/dl); her HbA1c: 6.3% (45 mmol/mol); her BP:120/80 mmHg; and her BMI: 26.7 Kg/m2 as well as a normal lipid profile.

True or False: you explain that she is doing very well on insulin and because of that it is preferable that she stays on insulin.

Response: False

Explanation

Both the risk/benefit ratio and the wish of each individual should be considered when designing treatment regimens. Janet is metabolically stable and is maintaining her blood glucose levels below her glycemic target. She has demonstrated a clear ability to manage her condition. Transitioning from insulin to metformin is therefore a possibility and something that Janet wishes to pursue. The insulin dosage should be tapered gradually to avoid hypoglycemia while steadily introducing metformin [11]. Transition from insulin to metformin can easily be achieved by decreasing insulin dose by 10- 20% each time the metformin dose is increased [11]. You should begin with metformin 250 mg once a day for 3 to 4 days then increase to twice a day if tolerated. Continue to titrate the dose in this manner over 3 to 4 weeks until the maximum dose of 1000 mg twice a day is reached. Meticulous SMBG is integral throughout this process; if the blood glucose reach the impaired range at any time, the taper should be slowed [11].

In conclusion, 3 years have elapsed since Janet was first time diagnosed with T2DM. She managed her T2DM well using metformin plus appropriate eating and regular physical activity. As a consequence, she is much happier and has lost 10 kg. Her FPG: 6.4 mmol/L (115 mg/ dl); her HbA1c: 6.1% (43 mmol/mol); her BP: 116/74 mmHg; and her BMI: 24.6 Kg/m2. The HCP continues to stresses on the importance of LSI to prevent disease progression for her and other member of the family. Now Janet is mostly an adult and if she begins to fail on metformin, she can return on insulin but she will be authorized to get access to a greater variety of OADs to control her T2DM and with the research progress she will eventually be able with the development of pharmacogenetics and pharmacogenomics to get access to personalized treatment.

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Personalised Medicine for the Treatment of T2DM

Case Report

Introduction

Personalized medicine aims at better targeting therapeutic intervention to the individual by maximizing the benefits and minimizing harms associated with drugs. T2DM is a heterogeneous disease with an important genetic background. The underlying pathogenic mechanisms and the clinical features markedly vary among patients [1-3]. The American Diabetes Association (ADA), the European Association for the Study of Diabetes (EASD) position statement on T2DM management and the American Association of Clinical Endocrinologists (AACE) clearly mention that the choice of T2DM goal therapies of reaching an HbA1c of < 7% for all patients should be replaced by a more patient-individualized approach based on attributes specific to both the patients and the medications themselves [4-6].

Individual drug response may vary due to many factors such as: 1). Individual characteristics of the patient: age, gender, BMI or comorbidities; liver and/or kidney function and others; 2). polymorphisms in genes encoding drug-metabolizing enzymes, transporters, receptors and molecules involved in signal transduction; 3). some specificities of the disease itself such as the known duration of T2DM that may influence the magnitude of the beta-cell defect, its severity as quantified by the increase in HbA1c; 4). the main components of the pathophysiology of the disease, especially the relative contributions of the defect in insulin secretion and insulin resistance; 5) the properties of the OADs especially their specific mode of action tackling the most crucial pathophysiological defects and targeting fasting and/or postprandial hyperglycaemia; and 6). the PKs parameters that may be altered by comorbidities such as renal or hepatic impairment but also by genetic background and polymorphism in enzymes or transporters playing a key role in drug metabolism leading to a true individual drug response [7-8].

However, we are at some point already going for an individualized approach in the treatment of T2DM that is based on our understanding of some of the pathophysiology of the disease such as their risk for hypoglycemia, how long the patients have had the disease, whether they have other important comorbidities, their risk of weight gain and their motivation status. We actually have very good guidelines based on outcome data to suggest how we should individualize treatment targets. Specifically, the ADA has put forward a very interesting graphical representation of individual physiologic and patient-centered patient-centered aspects (https: //durobojh7gocg.cloudfront.net/content/ diacare/38/1/140/F1.large.jpg) that the HCP should incorporate in the selection of our treatment target and in the selection of the appropriate medication. However, a great inter-individual variability exists in the clinical outcomes of glucose-lowering agents, especially for the OADs [7-8]. Therefore, the poor therapeutic outcomes that we often observed with a specific medication may be caused by treating patients without being concern for the individual pharmacogenetic and/or the pharmacogenomic characteristics that might influence the drug response.

Therefore, understanding the basis of this heterogeneity should provide an opportunity for better personalising treatment strategies according to individual patient clinical characteristics and the molecular characteristics of the OADs [9-11]. This case report will discuss both the opportunities and the challenges of personalised medicine and how this new treatment issue may lead to a better individualized treatment of T2DM. Although, the treatment of pediatric T2DM is rather limited to insulin and metformin, if we consider that the mean age that most pediatric patients are diagnosed with T2DM is around 14 years-old, these adolescents will become rapidly adult’s patients and we believe that it is a very good opportunity to introduce this topic within this special issue to better prepare the HPC to this new era of treating T2DM.

Case Report

Joseph is a 16 year-old obese (BMI 32 kg/m2) European- American that came to your office with her mother because he presented symptoms of T2DM. With this limited information what should be the individual characteristics and disease-related biological characteristics you need to consider in the objective of personalising Joseph’s treatment in case he receive the diagnosis of T2DM?

(A) His age;

(B) His gender;

(C) His BMI;

(D) His race/ethnicity;

(E) His markers of insulin secretion (C-peptide);

(F) His markers of disease severity (HbA1c)

(G) His fasting versus postprandial hyperglycaemia;

(H) His markers of insulin resistance (metabolic syndrome);

(I) The presence or not of renal impairment.

(J) The presence or not of liver disease.

(K) All of the above.

Answer: K

Explanations

A) His Age

As mentioned on many occasion in previous articles, the onset of T2DM at an early age points to a glycaemic legacy if the disease is uncontrolled for long periods of time. Many of these patients are obese at diagnosis and also have co-morbidities such as HTN, dyslipidaemia and microalbuminuria at a relatively early age which put them at risk of early CVD. Although LSI may be helpful in the management of many of these co-morbidities, pharmacotherapy with the aim of preserving β-cell function and improving insulin sensitivity should often be added. At present, metformin is the only OAD approved for use in children and adolescent. However, recent data from the Treatment Options for Type 2 Diabetes and Adolescents and Youth (TODAY) study showed that 50% of children and adolescent failed to maintain durable glycaemic control with metformin monotherapy and combination therapy or insulin was often necessary within a few years of diagnosis. Although not discussed in this article, it is possible to suggest the presence of a pharmacogenomic and pharmacogenetic components to explain this relatively poor response to metformin (See below). Therefore, agents that address insulin resistance other than metformin can potentially help to preserve β-cell function (DPP-4 inhibitors and GLP-1 receptor agonists) should be considered given that the disease will progress over many decades. The choice of medication based on Joseph genetic information will be further discussed below.

B) His gender

Differences in gender responses to therapy may be considered when individualizing treatment for people with T2DM as it is an important personal characteristic [7, 12]. For instance, females had smaller decreases in HbA1c and were less likely to reach glycaemic targets despite higher insulin doses and more hypoglycaemic events than males [7]. However, no obvious gender-related differences were reported with OADs so far. Further studies are required to clarify whether or not a gender-related difference clearly exists for OADs. However, for the reasons discussed in previous articles including those related to the puberty; in the context of clinical practice gender should always be considered in personalising treatment.

C) His BMI

When only two classes of OADs were available, metformin was preferred in obese patients while sulphonylureas were considered as a better option in non-obese patients with T2DM. Now metformin is considered as the first-line therapy in all patients with T2DM [8] in the absence of contraindications that include acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma, history of ketoacidosis with or without coma and relevant gastrointestinal symptoms; those patients should rather be treated with insulin [13]. Currently, OADs can be separated according to their effects on body weight: some inducing weight gain (sulphonylureas, glitazones, insulin), others being weight neutral or inducing only mild weight reduction (metformin, DPP-4 inhibitors) and others associated with significant weight loss (SGLT2 inhibitors, glucagon-like peptide-1 or GLP-1 receptor agonists) [7, 14-15]. These differential weight effects may influence HCP’s preferred choice according to patient’s initial body weight and desire of weight change. Considering that our patient is obese, choosing a medication that has a positive effect on weight loss can be a good choice in personalising his treatment.

Therefore, medications in the class of SGLT2 inhibitors or GLP-1 receptor agonist should be considered. However, other clinical and genetic considerations needs to be assessed before deciding which medication should be the best for Joseph. This will be further discussed below.

D) His race/ethnicity

Differing effects of metformin on glycaemic control by race-ethnicity have been reported. For instance, African American individuals appear to have a better glycaemic response to metformin when compared with European Americans [16]. DPP-4 inhibitors exhibit a better glucose-lowering efficacy in Asians than in other ethnic groups. However, the precise underlying mechanisms remain unknown [17] and other research are also needed to further document the impact of race/ethnicity on the choice of the most appropriate OADs to treat their T2DM. The fact that our patient is European American may indicate that his response to metformin may be reduced with time. That is why it is important to note this information in the context on personalising treatment of T2DM.

E) His markers of insulin secretion (C-peptide)

T2DM is an evolving disease characterized by a progressive loss of β-cell function and a decline in insulin secretory capacities, which results in the progression of the disease [7]. Disease progression and interindividual response to OADs varies markedly among patients with T2DM (18). Because some OADs mainly promote insulin secretion while others rather act primarily on insulin sensitivity, the residual insulin secretion should influence the drug-related response regarding improvement of glucose control in patients with T2DM [19- 20]. Therefore, measurement of plasma C-peptide has been suggested of being of clinical utility in the assessment of patients with T2DM [19]. However, there is limited evidence to support the use of C-peptide to predict treatment response in patients with T2DM [21]. Nevertheless, the recent development of incretin-based therapies may somewhat change this approach. Indeed, severe insulin deficiency as evidenced by low plasma C-peptide concentrations predicts a poor to a non-response to GLP-1 receptor agonists [22-23]. Again, this information is particularly relevant when we will have to decide which OADs is the best for our patient. For instance, the patient may have specific gene in favor of specific OADs but without the supporting clinical information the patient is no longer a candidate to receive these medications. Which means that the genetic information should be supported by the clinical information to obtain the best personalised treatment?

F) His markers of disease severity (HbA1c)

The level of HbA1c, used as a validated marker of glucose control during recent weeks, is the main marker use to guide the choice of therapy. Initiation of insulin therapy rather than OADs is recommended in patients with T2DM who present with an initial HbA1c level > 9% (75 mmol/mol) and symptoms related to hyperglycaemia. When the HbA1c is above 8.0–8.5%, the likelihood of achieving glycaemic targets with a single OAD diminishes drastically. These patients may be better candidates for treatment with a combination of OADs as first-line therapy [24], although this is not commonly done yet in clinical practice [25]. Whatever the glucose-lowering agent used, the higher the baseline HbA1c level, the greater the reduction in HbA1c achieved [26]. However, the impact of the increase in baseline HbA1c on the clinical efficacy of a SGLT2 inhibitor is greater than that of a DPP-4 inhibitor [27]. This difference can be explained by the greater amount of glucose removed from the body by SGLT2 inhibitors at the higher plasma glucose concentration. In contrast, high HbA1c may suggest a profound defect in insulin secretion, which may limit the efficacy of DPP-4 inhibitors [28-30]. Thus SGLT2 inhibitors may be preferred to DPP-4 inhibitors in T2DM patients with high initial HbA1c [7, 27]. Knowing the initial HbA1c level is not questionable as it is one of the main characteristic that the HCP should know before initiating T2DM treatment and this has been largely discussed in previous articles. However, it is now evident that this information is essential in the selection of the appropriate OAD not only for the initial treatment of T2DM but also as a second-line treatment; for instance when patients are no longer responding to metformin as in 50% of patients in the TODAY study.

G) His Fasting versus postprandial hyperglycaemia

HbA1c value gives an integrated view of overall glucose control during the last 2–3 months, but does not allow discriminating between preponderant contributions of fasting or postprandial hyperglycaemia [31]. Some OADs are mainly active on fasting hyperglycaemia (metformin, thiazolidinediones, basal insulin) while others are mainly targeting postprandial hyperglycaemia (incretin-based therapies, acarbose, prandial insulin bolus). In a meta-analysis exploring 24- week effects on HbA1c of maximal doses of DPP-4 inhibitors, DPP-4 inhibitors appear to be more effective in patients with mild/moderate fasting hyperglycaemia [32]. Short-acting GLP-1 receptor agonists (i.e. exenatide) mainly target postprandial hyperglycaemia whereas long-acting receptor agonist (i.e. liraglutide) mainly targets fasting hyperglycaemia [33]. Thus, the individual relative contributions of fasting versus postprandial hyperglycaemia may be helpful in choosing the best OAD therapy in patients with T2DM [34, 31]. That is why it is important to get this information in the assessment of each patient with T2DM.

H) His markers of insulin resistance (metabolic syndrome)

Insulin resistance syndrome is linked to abdominal obesity and is usually associated with biological markers of the metabolic syndrome that includes HTN, abdominal obesity, dyslipidemia and dysglycemia. Therefore, the presence of atherogenic dyslipidaemia (hypertriglyceridaemia, low HDL, HTN and abdominal obesity should encourage the prescription of agents that can promote weight loss (SGLT-2 inhibitors, GLP-1 receptor agonists) and/or improve insulin resistance (pioglitazone) [13-15]. NAFLD is rather common in patients with poorly controlled T2DM and metabolic syndrome and could be improved with pioglitazone [35] or liraglutide [36]. Therefore, knowing the presence of the markers of insulin resistance may be helpful in choosing the best OAD therapy in patients with T2DM.

I) The presence or not of renal impairment

As discussed in article number 2, CKD is a frequent complication in patients with T2DM, especially after a long duration of hyperglycaemia, especially when HTN is present. The presence of renal impairment has to be taken into account when selecting both the type and the dose of the OADs in patients with T2DM [12]. More particularly, this is the case for metformin [13], incretin-based therapies (DPP-4 inhibitors and GLP-1 receptor agonists) [16] and SGLT2 inhibitors [37]. The risk of hypoglycaemia is also increased in T2DM patients receiving most sulphonylureas in the presence of renal insufficiency [12]. Again, it is essential to know whether or not we are in presence of renal impairment before choosing the best OAD therapy in patients with T2DM.

J) The presence or not of liver disease

Severe liver disease is much less frequent than CKD in patients with T2DM. If present, it should impose cautious selection of both type and dose of OADs to minimize the risk of adverse drug reactions [38]. However, NAFLD is common in patients with T2DM. Some OADs have proven to be more efficacious to reduce hepatic fat content than others, especially thiazolidinediones (pioglitazone) [35] and GLP-1 receptor agonists (liraglutide) [36]. The presence of a liver disease can easily be found by simply doing a liver profile. This will also permit to screen for the presence of NAFDL. Again, this information is relevant before prescribing the most appropriate medication for a specific patient.

You have completed the investigation and you found that this patient had T2DM. It was then treated with insulin and LSI for few months. After one year with this treatment he was transfer to metformin and LSI. He lost 5 kg of body weight, which means that he is no longer obese but still have difficulties controlling his weight and his blood glucose and had some gastrointestinal intolerance on metformin despite being highly compliant to the HCP and diabetic nurse recommendations. His blood pressure was normal as well as his lipid profile and his liver profile was normal too suggesting the absence of NAFDL and liver diseases. His last HbA1c has increased to 7.8% recently added to his digestive symptoms with metformin consequently he had to return on insulin but does not want to stay on insulin for a long period of time. His C-peptide is at 1.7 mmol/L (0.2-1.0mmoll) suggesting the presence of insulin resistance but not insulin deficiency. His ACR is of 0.88 mg/mmol (<3.5 mg/mmol); and his eGFR is of 118 ml/min (90- 120 ml/min) suggesting the absence of renal impairment. Joseph has no problem with fasting or post prandial hyperglycemia in the past few months as seen on his SBGM. After 6 months, you are planning to change his insulin for a new medication since he is now18 years-old but before that you decided to send him to a research center for a genetic consult in order to determine which medication should be the most appropriate for him. You got the following results from the genetic consult. The patient had OCT1 variants encoded by the gene

SLC22A1; variant alleles in TCF7L2 and IRS-1 genes; the presence of the SLCO1B1*1B (c.388G-c.521T) haplotype; the presence of PPAR- γ. 12Ala carriers; variants of the transcription factor 7- like 2 genes (TCF7L2) and the rs6923761 variant of the GLP-1R gene. Based on this genetic information what should be the treatment of choice?

(A) Biguanides (metformin);

(B) Sulphonylureas;

(C) Meglitinides (repaglinide, nateglinide);

(D) Thiazolidinediones (TZD) (pioglitazone, rosiglitazone);

(E) Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins);

(F) Glucagon-like peptide-1 (GLP-1) agonist (Liraglutide, Exenatide)

(G) Sodium–glucose cotransporters type 2 (SGLT2) inhibitors (gliflozins)

(H) Only C, D and F are correct

Answer: H

Explanations

A) Biguanides (Metformin)

Metformin has been a cornerstone in T2DM management even if its mechanism of action remains unclear [7]. At the moment, it seems to lower blood glucose through hepatic diminution of glucose production and an increase of peripheral insulin sensitization [39]. Despite its wide and, generally, well tolerated utilisation, according to the TODAY study, 50% of patients are poor responders and up to 63% are experiencing important gastrointestinal adverse reactions [39]. Because of its positive charge, metformin is, most likely, transported by organic action transporters (OCTs); plasma membrane monoamine transporter (PMAT), OCT1 and OCT3 may be responsible for its intestinal absorption, OCT1 and MATE1 for its transport to the liver and biliary excretion, respectively whereas OCT2 seems implicated to its transport to the kidney and MATE1/2 for its secretion [39]. However, some of them were found, by GWAS, to possibly have genetic variants implicated in response variability to OADs [7].

OCT1 encoded by the gene SLC22A1, has been the focus of many studies and results of its variants have been ambiguous about its influence on drug response [7]. Overall, it seems that there is a lower efficacy of metformin with individual having one or more variants associated with reduced function and gastrointestinal intolerance was significantly higher in individual showing reduced function in both alleles [39-40]. OCT2 has been studied mostly in Asian populations and heterozygous GT alleles individuals appear to be associated with better PKs results [39]. As for MATE1 and MATE2, fewer results are available, however, homozygous for minor allele in some variants showed higher and lower, respectively, HbA1c reduction [39]. Also, genetic variants found in OCT1, OCT2 and MATE1 were associated with lower incidence of T2DM or protection effects after metformin treatment [39]. In a large GWAS, ATM gene was linked to better HbA1c reduction for its minor allele but was not found to reduce T2DM progression [60, 84]. Finally, two variants in and around transcription factors gene SP1 were associated with lower HbA1c diminution and lower clearance [39]. Hence, from these equivocal results emphases the need for further studies but also, the important role that genetic profiling could have in metformin treatment, its response and better control over its adverse effects [7]. Therefore, the OCT1 variants encoded by the gene SLC22A1 may at some point explain why this patient became less responsive to metformin therapy and explain his gastrointestinal intolerance. Finally A is not a good answer.

B) Sulphonylureas

Used as first-line and add-on therapy, SUs are known to activate ATP potassium channel in pancreatic β-cell thus leading to a release of glucose-independent insulin. Ten to twenty percent of patient under SU treatment will have a small fasting plasma glucose reduction [39]. Therefore, genetic studies which focused on SU mostly targeted genes that are linked to insulin secretion. Numerous genes and cytochrome P450 (CYP450) were associated to genetic variants that could influence SUs response in T2DM patients [7]. Polymorphisms in CYP enzymes are widely studied, CYP2C9 and CYP2C19 variants have been implicated in T2DM that could altered SU metabolism and response [23, 38, 42]. Asian carriers of a defective allele of CYP2C9 (*3) and CYP2C19 (*3) seems to be particularly affected by SU administration leading to increase PKs parameters whereas Caucasians with affected alleles (*2 or *3), though ambiguous, were associated to higher risk of hypoglycaemia and lower clearance of glucose [23, 38, 42].

ABCC8, KCNJ11, TCF7L2 and IRS-1 are some the genes that were associated to impact SUs response. Two variants in ABCC8, S1369A and E23K, reported higher fasting plasma glucose and HbA1c reductions in Chinese using gliclazide and higher therapy failure associated to K allele when glibenclamide was taken, respectively. As for KCNJ11, results are ambivalent; some studies showed no difference and others implied that K allele was linked to higher HbA1c reduction, lower risk of hypoglycaemia and fasting plasma glucose (39). Variant alleles in TCF7L2 and IRS-1 genes have been associated with treatment failure; first and second SUs treatments for TCF7L2 and secondary treatment for IRS-1 [39, 43-45]. Therefore considering the presence of these variant alleles in TCF7L2 and IRS-1 genes sulphonylureas are not appropriate OADs for Joseph.

C) Meglitinides (repaglinide, nateglinide)

Possible reasons for interindividual variability in response to meglitinides may result from polymorphisms in organic anion transporting polypeptide 1B1 (OATP1B1) gene (SLCO1B1) or the metabolizing enzyme of the CYP family [46]. Nateglinide is metabolised by CYP2C9 whereas repaglinide is metabolised by CYP2C8 [42, 47]. Moderate dose adjustments based on CYP2C9 genotypes may help in reducing interindividual variability in the antihyperglycaemic effects of nateglinide. CYP2C8*3 carriers had higher clearance of repaglinide than carriers of the wild-type genotypes. Although genetic variants in metabolizing enzymes of the CYP family may alter the PK of the medications of the meglitinide family, they do not appear to have major effects on the glucose levels of T2DM patients [7-8, 46].

The SLCO1B1*1B (c.388G-c.521T) haplotype is associated with enhanced hepatic uptake and decreased plasma concentrations of some OATP1B1 substrates. The SLCO1B1 c.521CC genotype has been associated with increased and the SLCO1B1*1B/*1B genotype with decreased exposure to repaglinide. Accordingly, SLCO1B1 genotyping may theoretically help in choosing the optimal starting dose of repaglinide [48]. In Chinese individuals, the SLCO1B1 c.521C allele has been associated with increased plasma concentrations of nateglinide, but the association could not be replicated in Caucasians [48]. Other studies are warranted to examine the association between repaglinide or nateglinide efficacy and safety and different polymorphisms. The presence of the SLCO1B1*1B (c.388G-c.521T) haplotype may have a beneficial effect in the response to meglitinides. Therefore C is a good answer.

D) Thiazolidinediones (TZD) (pioglitazone, rosiglitazone)

CYP2C8 and CYP3A4 are the main enzymes catalyzing the biotransformation of pioglitazone (and troglitazone, a TZD withdrawn because hepatotoxicity), whereas rosiglitazone is metabolized by CYP2C9 and CYP2C8 [42, 49]. SLCO1B1 genotype has had no effect on the PK of rosiglitazone, pioglitazone or their metabolites [48].

The genes coding for CYP2C8 and PPAR (peroxisome proliferator activated receptor)-gamma (γ) are the most extensively studied to date and selected polymorphisms may contribute to respective variability in pioglitazone PK and PDs, which may impact both efficacy and toxicity of the drug [50]. CYP2C8*3 was associated with lower plasma levels of rosiglitazone and hence a reduced therapeutic response but also a lower risk of developing oedema, which suggests that individualised treatment with rosiglitazone on the basis of the CYP2C8 genotype may therefore be possible [51]. However, the studies that looked at the association between CYP polymorphisms and TZD toxicity were inconsistent and generally did not produce statistically significant results. Therefore, it can only be speculated that polymorphisms in TZD-metabolizing enzymes are associated with toxicity [46].

Specific genetic variations in genes involved in the pathways regulated by TZDs could also influence the variability in treatment with these drugs [52]. A first study showed that the Pro12Ala variant in the PPAR- γ gene does not affect the efficacy of pioglitazone in patients with T2DM, suggesting that the glucose-lowering response is independent from pharmacogenetic interactions between PPAR- γ and its ligand pioglitazone [53]. However, in a more recent meta-analysis, which synthesized the currently available data on the PPAR- γ. Pro12Ala polymorphism, PPAR- γ. 12Ala carriers had a more favourable change in fasting blood glucose from baseline as compared to patients with the wild-type Pro12Pro genotype [50]. In a study investigating the influence of the S447X variant in lipoprotein lipase (LPL) gene on the response to therapy with the TZD pioglitazone, the S447X genotype conferred a statistically significant reduction in glucose-lowering response rate to pioglitazone as well as a less favourable lipid lowering response relative to the S447S genotype (54). In a study in Chinese patients with T2DM, the adiponectin gene polymorphism rs2241766 T/G was associated with pioglitazone efficacy [55]. Therefore, pharmacogenomics and pharmacogenetics may be an important tool in drug individualization and therapeutic optimization when prescribing TZDs in patients with T2DM [52]. The presence of PPAR- γ. 12Ala carriers indicates that this drug might be a good choice in the treatment of Joseph’s T2DM. Therefore, D is a good answer.

E) Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins)

DPP-4 inhibitors (gliptins) are increasingly used in the management of patients with T2DM, essentially because of a good safety profile [56]. The liver is not important for the elimination or action of sitagliptin, vildagliptin and saxagliptin [57]. Therefore, SLCO1B1 polymorphism unlikely affects the response to these OADs. ABCB1 polymorphisms (ABCB1 CGC/CGC, CGC/TTT, and TTT/ TTT diplotypes) did not influence sitagliptin PK in healthy volunteers [59]. Cytochrome P450 (P450) enzymes CYP3A4 and CYP3A5 metabolize saxagliptin and 5-hydroxy saxagliptin (M2), its major, active metabolite. Kinetic experiments indicated that the catalytic efficiency for the CYP3A4 was approximately 4-fold higher than that for the CYP3A5. Therefore, it is unlikely that variability in expression levels of CYP3A5 due to genetic polymorphism will impact clearance of saxagliptin [60].

Individuals carrying variants of the transcription factor 7- like 2 gene (TCF7L2) are at increased risk for T2DM and may have diminished pancreatic islet-cell responsiveness to incretins. Linagliptin significantly improved hyperglycaemia in T2DM patients both with and without the TCF7L2 gene diabetes risk alleles, although HbA1c response was significantly reduced in TT compared with CC patients [61]. Thus, diabetes susceptibility genes may be a contributor to the inter-individual variability of treatment response to DPP-4 inhibitors. In a large primary care database recently analyzed to assess the variability in response to a DPP-4 inhibitor, HbA1c reductions were significantly lower with increased T2DM duration, in agreement with a defective insulin secretion [28]. These data are in agreement with previous studies having measured insulin secretion in T2DM patients treated with sitagliptin [29] or vildagliptin [30]. Because this patients is carrying variants of the transcription factor 7- like 2 genes (TCF7L2), he may have diminished pancreatic islet-cell responsiveness to DPP-4 inhibitors (gliptins) is not a good choice for him. Therefore, E is not a good answer. However, we should consider that the genetic studies focusing on the variability of response to DPP-4 inhibitors are scarce and poorly contributive.

F) Glucagon-like peptide-1 (GLP-1) agonist

GLP-1 is an incretin that is known to induce insulin secretion of the β-cells. GLP-1 receptors (GLP-1R) agonists sustain insulin secretion consequently increasing the efficacy in the treatmet of T2DM. Encoded by GLP1R gene, GLP-1R is logically listed as one of the target that could affect treatment’s response. Studies associated to GLP-1R agonist have found that there are three genetic variants that might influence its response. However, still unclear results ensue from these researches [62-64]. T allele of rs3765467 and rs761386 were linked to lower and higher standard deviation in plasma glucose in response to exogenous GLP-1, respectively. The rs6923761 variant has shown an increased response from β-cells. Since this patient is carrying the rs6923761 variant of the GLP-1R gene he may have increased pancreatic β-cells responsiveness to GLP-1. Therefore F is a good response and according to Joseph clinical presentation a GLP- 1 agonist is probably the better choice for him and this is consistent with the most recent Canadian Clinical Practice Guideline http: // guidelines.diabetes.ca/bloodglucoselowering/pharmacologyt2.

G) Sodium–glucose cotransporters type 2 (SGLT2) inhibitors (gliflozins)

SGLT2 inhibitors is a glucose transporter situated in the kidney, it blocks the reabsorption of filtered glucose, leading to glucosuria [7]. The SGLT2 gene (SLC5) has been mapped to chromosome 16 p11.2, and up to 50 different mutations of this gene have been reported in the context of familial renal glucosuria [63]. SLC5A2, a gene implicated in glucose transport, holds a genetic variant, rs9934336, from which the G allele was associated with increased exposure to the drug [64]. SGLT-2 inhibitors are eliminated by uridine diphosphate glucononyltransferases (UGTs) and as for CYPs, they are known to be associated with genetic variant that can alter their function [7]. So far, there have been no definitive studies of patients with T2DM regarding the genetic variants and SNPs associated with response to the SGLT2 inhibitors.

Conclusion

According to the pharmacogenetic assessesment performed on Joseph, we now know that he could have a very good response in his T2DM treatment by using one of the following OADs: Meglitinides (repaglinide, nateglinide); Thiazolidinediones (TZD) (pioglitazone, rosiglitazone); and Glucagon-like peptide-1 (GLP-1) agonist. This information is particularly pertinent for the HCPs in deciding which OAD he will prescribe to Joseph. However, the HCPs cannot only use the information from genotypic markers for selecting and adjusting T2DM therapy and still need to corroborate this information with the clinical information obtained by the clinic and still need to follow the recommendation from clinical practice guidelines Understanding variations in genetics, environment and lifestyle in order to adapt care to each individual is the ultimate objective of precision medicine. As seen in this case report, pharmacogenomics and pharmacogenetics holds a great deal of opportunities toward that goal of personalized care. The cost of personalised medicine should be compensated for by better efficacy, less adverse drug reactions and ultimately less complications associated to T2DM, leading to improved quality of life and increased life expectancy. Eventually, the developments in the field of personalised medicine for T2DM will likely translate, into clinical practices to individualise therapy that will improve both patient outcome and public health.

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Impaired Awareness of Hypoglycaemia in an Obese Woman with Type 2 Diabetes Mellitus

Case Report

Jane is a 46 year-old obese woman with a 28 year history of type 2 diabetes (T2DM) presented to the clinic following a loss of consciousness the previous day. Her loss of consciousness took place at home and the patient was awake at the time of the incident. This was witnessed by her husband, who administered intramuscular glucagon immediately. After regaining consciousness, the patient consumed a meal consisting of complex carbohydrates. Her blood glucose was not checked at the time of the unconsciousness, but was normal after treatment (glucagon + orange juice). Her T2DM was managed with 32 units of rapid-acting insulin glulisine (Apidra) accompanying each meal and 52 units of long-acting insulin glargine (Lantus) at bedtime. She was also treated with LSI but she was always irregular in the follow-up of her diet and physical activity regimens. She denied having any recent problems with hypoglycaemia and reported that she measured her blood glucose at least once a day and it was ‘always normal’. She is a bus driver and had a traffic accident 2 years ago but she was unable to recall the details. Nobody was injured during the accident which occurred at a very low speed but was witnessed by a client.

What should you ask on medical history?

HCPs should follow the ‘6As model of counselling and assess about the frequency and timing of severe hypoglycaemia, individual awareness of hypoglycemia, hypoglycaemia detected by others, and hypoglycaemia detected only because of monitoring [1-3]. The HCPs should also asses for risk factors for impaired awareness of hypoglycaemia (IAH) (see definition below) that includes age over 50, infrequent self-monitoring of blood glucose (SMBG), duration of diabetes longer than 10 years, glycemic control with glycated hemoglobin (A1C) less than 0.070 (Optimal control is < 0.070, Sub optimal 0.070 – 0.084; inadequate > 0.084) and episodes of hypoglycemia where assistance was required or where there was a loss of consciousness. Then the HCPs assess about drugs used including beta-blockers (non-selective), hypnotics, tranquillisers and alcohol. The HCPs should also assess for the social support including the fear of hypoglycemia, and the impact or anxiety on other family members. He should assess her daily routine for insulin administration, eating patterns, exercise routine, the frequency of SMBG and the distribution of hypoglycemia [1-6].

Finally, the HCP complete the following questionnaire with the patient by asking specific questions related to hypoglycemia according to the Clarke’s questionnaire (5) aims to quantify the degree of IAH. Each response is rated R for ‘reduced awareness’ or A for ‘aware’. A patient who provides four or more R responses is considered to have IAH. The questions are as follows:

1) Do you always have symptoms when your blood sugar is low (A) Do you sometimes have symptoms when your blood sugar is low R.

Response: I do not always have symptoms when my blood sugar is low (1).

2) Have you lost some of the symptoms that used to occur when your blood sugar was low?

Yes (R) No (A);

Response: Yes sometimes (1).

3) In the past six months how often have you had moderate hypoglycemia episodes? (Episodes where you might feel confused, disoriented, or lethargic and were unable to treat yourself)

Never (A) Once or twice (R) Every other month (R) Once a month (R) More than once a month (R)

Response: Yes it happened once or twice (1).

4) In the past year how often have you had severe hypoglycemic episodes?

(Episodes where you were unconscious or had a seizure and needed glucagon or intravenous glucose) Never (A) 1 time (R) 2 times (R) 3 times (R) 5 times (R) 6 times (R) 7 times (R) 8 times (R) 9 times (R) 10 times (R) 11 times (R) 12 or more times (U)

Response: I had one episode last year and one yesterday (1).

5) How often in the last month have you had readings

Never 1 to 3 times 1 time/week 2 to 3 times/week 4 to 5 times/ week Almost daily (R = answer to 5 < answer to 6, A = answer to 6 > answer to 5)

Response: Maybe 1–2 times per week.

6) How often in the last month have you had readings answer to 5)

Response: Maybe 1–2 times per week.

7) How low does your blood sugar need to go before you feel symptoms?

60-69 mg/dl (3.33 – 3.8 mmol/L) (A)

50-59 mg/dl (2.8 – 3.3 mmol/L) (A)

40-49 mg/dl (2.22 – 2.72 mmol/L) (R) < 40 mg/dl (< 2.2 mmol/L) (R)

Response: Between 2.22 – 2.72 mmol/L (1)

8) To what extent can you tell by your symptoms that your blood sugar is low?

Never (R) Rarely (R) Sometimes (R) Often (A) Always (A)

Response: Often.

What is the most likely diagnosis?

The patient scored “5” on the questionnaire, consistent with a diagnosis of IAH. Hypoglycemia is a risk associated with insulin therapy, while impaired awareness has a physiologic basis related to the impact of hypoglycemia on the brain and an impaired response of counter-regulatory mechanisms in the setting of longstanding T1DM and insulin-treated T2DM. In patients with IAH, the ability to perceive the onset of hypoglycaemia becomes diminished or absent. Symptoms are insidious and include difficulty concentrating, confusion, reduced consciousness, coma or seizures before autonomic activation (tremor, sweating, palpitation and nausea) [4]. Impaired awareness of hypoglycaemia is believed to affect approximately 20- 25% of patients with T1DM and up to 10% of insulin-treated T2DM [4]. The condition increases the risk for severe hypoglycaemia by 3 to 6 fold compared to people with normal awareness [4]. It should be differentiated from “hypoglycaemia unawareness” which suggests a rare but total loss of symptomatic response to low glucose [4]. The differential diagnosis also includes a number of rare conditions, including all of the causes of syncope with the two broad categories being cardiac and neurological. The latter would include seizure disorders.

How will you treat this patient?

The key to reversing IAH is by adjusting the glucose target to avoid episodes of hypoglycaemia [4]. In order to achieve this goal, experts recommend frequent SMBG including pre-prandial and nocturnal measurements; avoidance of blood glucose values < 4 mmol/L, readjustment of blood glucose targets upwards (e.g., pre-prandial target 6.0 to 12 mmol/L and bedtime > 8 mmol/L), preventing A1C < 0.060 and inclusion of regular snacks between meals and at bedtime [1- 4]. Helping patients identify subtle cues to their low blood glucose is also recommended [1-4]. While the CDA Clinical Practice Guidelines give some recommendations about hypoglycemia and driving [3], this patient requires special consideration because her job requires that she drives and because she has had both a period of unconsciousness and a motor vehicle accident where IAH was a plausible explanation.

The Case Revisited:

We published a similar case 2 years ago and we resolved the case by decreasing all of his insulin doses by 30% and perform regular SMBG at least four times daily (pre-prandial and at bed time) [7]. Since then, the approach has evolved largely with the use of the ‘6As model of counselling discussed in a previous article of this special issue. But for this specific patient instead of reducing insulin as a target we are now approaching these patients by individualising their glucose target by using the following graphic: graphical representation of individual physiologic and patient-centered aspects
https://durobojh7gocg.cloudfront.net/content/diacare/38/1/140/F1.large.jpg
. Therefore, by simply personalising or adjusting her personal glucose target we were able to reduce her insulin doses and correct her IAH. I think that the HCP should now personalise more the treatment of patients with T2DM based on an individual glucose target rather than focusing on treatment target and I think it is the best lesson learn from this case. Because she was injured in a motor vehicle accident for which IAH played a plausible role, we notified the Ontario Ministry of Transportation who then investigated his suitability for driving, according to provincial law [8].

Regular SMBG demonstrated frequent asymptomatic hypoglycaemia requiring further reductions in her insulin dose. With our recommended treatment she was able to avoid hypoglycaemia completely and to reduce his total daily insulin dose by another 20% over a period of three months. Simultaneously, she began regaining warning symptoms when her blood glucose fell into the hypoglycaemic range. She was allowed to drive again with a non-commercial license provided that she does SMBG prior to driving and periodically during every driving exposure [8-10]. Our patient was able to organize a change in her work functions which permitted her to keep her job but not as a bus driver but as a road supervisor without clients. The present case emphasizes the importance of constantly personalising glucose target throughout treatment with insulin. The following points should also be considered [7]:

  • Structured patient education program about symptoms of hypoglycaemia and hypoglycaemia avoidance, SMBG, the adequate use of insulin; management strategies (carbohydrate intake and insulin dose) for exercise training, alcohol intake and the appropriate selection of food for meals and snacks [2];
  • Strategies to increase compliance to therapeutic modalities should be emphasized to restore hypoglycaemia awareness and to protect patients from severe hypoglycaemia [1-4].
  • People with IAH may require psychological counseling to help them modify the management of their diabetes and to address the problems of “low concern” or “denial” regarding hypoglycaemia unawareness often seen in these patients [6].
  • IAH poses a potential risk to safety, not only when driving, but also when exposed to heights or under water, operating machinery and other activities, and justifies the recommendation to perform SMBG in relation to such activities, even if this may seem inconvenient [1, 3].
  • Relatives should be taught about IAH and learn on how to administer glucagon (1mg subcutaneously, or intramuscularly) [3].
  • HCP should always remember to adjust treatment based on personalised glucose target throughout treatment with insulin.

References

  • Frier BM (2008) How hypoglycaemia can affect the life of a person with diabetes. Diabetes Metab Res Rev 24: 87-92. [crossref]
  • Choudhary P Amiel SA (2011) Hypoglycaemia: current management and controversies. Postgrad Med J 87: 298-306. [crossref]
  • Clayton D, Woo V, and Yale JF (2013) Hypoglycemia. Clinical Practice Guidelines. Canadian Diabetes Association Clinical Practice Guidelines Expert Committee. Can J Diabetes 37:S69-71.
  • Graveling AJ, Frier BM (2010) Impaired awareness of hypoglycaemia: a review. Diabetes Metab 36 Suppl 3: S64-74. [crossref]
  • Clarke WL, Cox DJ, Gonder-Frederick LA, et al. (1995) Reduced Awareness of Hypoglycemia in Adults with IDDM. A prospective study of hypoglycemia frequency and associated symptoms. Diabetes Care18:517-522.
  • Rogers HA, de Zoysa N and Amiel A (2012) Patients experience of hypoglycemia unawareness in Type 1 diabetes: are patients appropriately concerned? Diabet Med 29:321-327.
  • Plourde G, Klein AV2, Dent R2 (2014) Impaired awareness of hypoglycemia in a man with type 1 diabetes. CMAJ 186: 770-771. [crossref]
  • Begg IS, Yale J-F, Houlden RL, et al. (2003) Canadian Diabetes Association’s Clinical Practice Guidelines for Diabetes and Private and Commercial Driving. Can J Diabetes 27:128-140.
  • Canadian Medical Association (2012) CMA Driver’s Guide: Determining Medical Fitness to Operate Motor Vehicles. 8th Edition.
  • Canadian Diabetes Association’s Clinical Practice Guidelines for Diabetes and Private and Commercial Driving. Can J Diabetes 27:128-140

The Specific Impact of Fructose on the Development of Type 2 Diabetes Mellitus in Pediatric Patients

Abstract

Added fructose in particular i.e., as a constituent of added sucrose or as the main component of high-fructose sweeteners may pose the greatest problem for the development of obesity, T2DM, T2DM-related metabolic abnormalities in pediatric populations and CVD later in life. In contrary, whole foods that contain fructose i.e., fruits and vegetables pose no problem for health and are protective against the above metabolic disorders. Several dietary guidelines appropriately recommend consuming whole foods over foods with added sugars or sugary drinks (SSBs). For instance, in his 2016 Sugar Position Statement, the Canadian Diabetes Association (CDA) recommends reducing free sugar intake to a specific level of 10% of total calories intake i.e., to the level shown to improve glucose tolerance in humans and to decrease the prevalence of T2DM in both adults and pediatric patients. This level is also associated with an improvement of the metabolic complications that often precede and accompany T2DM. Reducing the intake of added sugars and fructose could translate in reduced T2DM-related morbidity and premature mortality. Finally, for our adolescent the recommendation that you as the HCP should give to the parents are no SSBs either fructose or not and to replace these beverages with water, % fruit juice (no added sugar) in limited amount (4 to 6 onces per day), vegetable juice or milk and to limit the intake of free sugar to the CDA recommendations. However, there is no risk to consume the recommended amount of five servings and more of fruits and vegetables per day despite the presence of fructose in these foods.

Introduction

Recent public health interest has focused on fructose as having a unique role in the pathogenesis of cardiometabolic diseases including obesity, T2DM and others [1-2]. However, because we rarely consume fructose in isolation, the major source of fructose in the diet comes from fructose-containing sugars, sucrose and high fructose corn syrup, in sugar-sweetened beverages (SSBs) and foods [2]. The intake of SSBs is now known to be linked to an increased risk of obesity and T2DM in various populations including pediatric population and the risk of developing CVD later in life. The underlying mechanisms is not completely known but include incomplete compensation for liquid calorie, adverse glycemic effects, and increased hepatic metabolism of fructose leading to an increased lipogenesis from the liver which results in a higher production of uric acid, and accumulation of visceral and ectopic fat [2]. In this mini review, with the use of a case report, we summarize the evidence evaluating the impact of added sugars, SSBs, and fructose on the risk of obesity, T2DM, and it’s associated CVD. We also discuss strategies to reduce the intake of fructose-containing sugar in order to answer questions raised by many parents and HCPs dealing with pediatric and adult patients suffering from obesity and T2DM.

Case report

During a subsequent visit, the parents came to the clinic for questions about the diet of her daughter Janet. Because she is obese and recently diagnosed with T2DM, the parents are concerned about the risk of losing control of her T2DM. They said that they should pay attention to the amount of fat, sugars and calories that Janet should ingest every day. On the other hand, they were a little confused regarding sugar: some people say that some sugar are to be avoided, including those added in the juice and food as well as those that are included in the soft drinks. On the other hand, it seems that there are no problems to consume diet drinks since they contains no calories and should be good to help Janet with her weight problem. Among the following, which one would you recommend to the parents?

(a) avoid all foods containing fructose.

(b) there is no risk to eat foods with sugar as long as it’s not fructose.

(c) there is no risk associated with “diet” drink.

(d) the use of sweeteners (artificial sugars) is a good choice.

(e) neither is true.

All these answers are wrong.

Answer: e

Explanations

(a) Avoid all foods containing fructose.

Fructose is the most frequent sugar used as sweetener in drinks like soft drinks, and energy drinks which are the single greatest source of calories and added sugars in the US diet, accounting for nearly half of all added sugar intake [3]. Fructose is also found in sucrose or common table sugar, which is a disaccharide composed of one glucose molecule and one fructose molecule linked via an α1–4 glycoside bond, and is obtained from either sugar cane or beets. Fructose and glucose are also both found as naturally occurring monosaccharides that exists in fruit, honey and some vegetables [2].

Sweeteners such as high fructose corn syrup (HFCS), produced from corn starch through industrial processing contain free fructose and free glucose in relatively equal proportions and have progressively replaced use of sugar due to its low cost. The most frequent forms of HFCS contain either 42 % (HFCS-42) or 55 % (HFCS-55) fructose, along with glucose and water. HFCS-55 has the sweetness equivalent of sucrose and is widely used to flavor carbonated soft drinks. HFCS- 42 is somewhat less sweet and is mainly used in processed foods including canned foods (e.g., soups, fruits), cereals, baked goods, desserts, sweetened dairy products, condiments, fruit-flavored noncarbonated beverages, candies, and many fast food items.

Longitudinal data over the past 40 years have shown a close relation between the rise in added sugar and obesity and T2DM epidemics in the US [4]. For now, there is no study in children to answer this question. On the other hand, according to a recent study performed in adults [5] consuming drinks sweetened with fructose and or glucose can increase abdominal fat and the levels of bad cholesterol, i.e., the low-density [LDL-C] cholesterol, two consequences related to an increased risk of CVD [6]. The study in question involved 32 adult subjects overweight or obese who had been asked to consume 25% of their total daily calorie needs by drinking a sweet drink with fructose or glucose, for 10 weeks. The two groups gained substantially the same amount of weight. However, the researchers found that fructose seemed to have more negative effects on the body weight. Indeed, people who drank sweetened drinks with fructose had higher levels of LDL-C, had a lower sensitivity to insulin and the highest rates of abdominal fat, which are known risk factors for CVD [6-7]. This confirms that excessive consumption of fructose, usually from SSBs can be unhealthy.

To ensure to avoid fructose, it is recommended that the consumers take time to read food labels when shopping to see if fructose is part of the ingredients. This will help them avoid fructose. It is also recommended to choose water, 100% fruit juice (no added sugar), vegetable juice or milk rather than the fructose-containing beverages. On the other hand, do not consider fructose as only being a dangerous sugar. Fruits and vegetables are the main natural source of fructose. Most of the fruits contain about 10 g of fructose. If fructose is toxic in high doses, people consuming large quantities of fruits would have undesirable effects, which is not the case. In addition, studies reported an inverse association between fruit consumption and body weight or the metabolic risks discussed above [8].

The absence of adverse effects associated with the consumption of fruits and vegetables in large quantities is related to a slower rate of digestibility for fruits and vegetables compared to drinks and processed foods sweetened with fructose. In addition, the presence of soluble fiber, and the cell structure of fruit and vegetables contribute to reduce the rate of absorption of fructose at the level of the digestive tract. We can add that the content in nutrients and antioxidants from fruits and vegetables protects against the inflammatory effect of fructose at the hepatic level and against the resistance to insulin at the systemic level. In other words, the small amounts of fructose consumed in vegetables and fruits are healthy for the body [8]. Therefore, there is no risk to consume the recommended amount of five servings and more of fruits and vegetables per day despite the presence of fructose in these foods.

The metabolism of fructose differs from that of glucose in two major ways. First, there is nearly complete hepatic extraction of fructose and second, there are different enzymatic reactions in the initial steps of the metabolism of fructose and glucose. Fructose is absorbed from the gut into the portal vein and is metabolized in the liver where it is converted into fructose-1-phosphate by the enzyme fructokinase [2]. Because these processes are not dependent on insulin, fructose is metabolized without requiring insulin secretion and without increasing plasma glucose. Of particular note, unlike glucose, fructose can bypass the main rate limiting step of glycolysis at the level of the enzyme phosphofructokinase, allowing it to act as a substrate for hepatic de novo lipogenesis resulting in an increased production of lipids [2]. The massive uptake and phosphorylation of fructose in the liver can also deplete intracellular ATP leading to an increase in uric acid production, which has been shown to induce metabolic complications [2]. These differences in hepatic metabolism can lead to a variety of different short- and long-term cardiometabolic effects of fructose compared with glucose.

(b) there is no risk to eat foods with sugar as long as it’s not fructose.

There are strong evidences indicating that SSB consumption is associated with an increased risk of T2DM through effects on adiposity and independently through other metabolic effects. A recent meta-analysis of 8 prospective cohort studies evaluating SSB intake and the risk of T2DM was performed (13). This study was based on 310,819 participants and 15,043 cases, individuals in the highest category of SSB intake composed of 1–2 servings per day. These individuals had a 26% greater risk of developing T2DM compared to those in the lowest category (none or less than one serving per month).

A similar association was found in a sub-cohort of 15,374 participants and 11,684 incident cases from the European Prospective Investigation into Cancer and Nutrition (EPIC) study [10] where a one serving per day increase in SSBs was associated with a 22% increased risk of T2DM. A recent meta-analysis of 17 cohort studies found that a one serving per day increase in SSBs was associated with an 18% increased risk of T2DM. Adjusting for BMI reduced this estimate to 13%. Given the similar estimates from studies in the US where HFSC is the primary sweetener and Europe where sucrose is used, there does not appear to be any appreciable difference regarding the impact of sweetener type on risk of T2DM. However, food sources of fructose may make a difference in metabolic effects. Some studies have shown beneficial effects of whole fruit consumption on risk of T2DM [11].

These results indicate that the liquid vs. solid forms of calories from sugars may impact metabolic diseases differently. Fructose in beverages is absorbed more quickly than fructose in whole foods such as fruit and vegetables, which are absorbed more slowly due to their fiber content and slow digestion. As mentioned earlier, the rapid absorption of liquid fructose increases the rate of hepatic extraction of fructose due to an increase in the lipogenesis from the liver which results in a higher production of lipids [2]. This new reality shows that excessive sugar consumption has harmful effects on health beyond his alleged role in obesity. In other words, too much sugar doesn’t just affect growth; it can also make us ill [12-13].

According to a recent study, more the consumption of added sugars is high and steady, more the risk of death from CVD increased [14]. There is also increasing evidence that higher SSB consumption increases CVD risk by contributing to the development of HTN, dyslipidemia, inflammation, coronary heart disease and stroke. In over 88,000 women in the NHS followed for 24 years, it was found that those who consumed 2 servings and more per day of SSBs had a 35% greater risk of CHD (non-fatal myocardial infarction or fatal CHD) compared with infrequent consumers [15]. Additional adjustment for potential mediating factors (including BMI, total energy intake and incident diabetes) attenuated the association, but it remained statistically significant, suggesting that the effect of SSBs may not be entirely mediated by these factors. Similar results were found in the HPFS among 42,883 men [16]. In this study, intake of SSBs was also significantly associated with increased plasma concentrations of inflammatory cytokines [16].

There is also evidence linking intake of SSBs to an increased risk of stroke. Among 84,085 women and 43,371 men in the Harvard cohorts followed for 28 and 22 years respectively, 1 serving and more of SSB per day was associated with 16% increased risk of total stroke compared with none in multivariable adjusted models including BMI [17]. This association was attenuated and no longer statistically significant after adjusting for HTN and T2DM, suggesting that these factors may be mediators. In the multi-ethnic cohort of 2,564 residents in Northern Manhattan followed for a mean of 10 years, daily soft drink consumption was associated with an increased risk of vascular events only in participants free of obesity, T2DM and metabolic syndrome at baseline and adjusted for a number of factors including BMI and HTN [18]. A Japanese cohort of 39,786 men and women followed for 18 years found significant positive associations between SSB intake and total and ischemic stroke in women but not in men in models adjusted for HTN and T2DM [19]. Adjustment for BMI and total energy intake had little effect on estimates, suggesting that these factors are not major mediators.

According to these researchers, we consume too much added sugar. It has been shown that between 2005 and 2010, 70% of adult foods contained at least 10 % of added sugars. Intake of both added sugar and SSBs was associated with an increased risk for CVD mortality in an analysis of NHANES III Linked Morality cohort data [20]. After a median of 14.6 years of follow-up, added sugar intake was associated with a 2-fold greater risk of CVD death comparing extreme quintiles of intake. In contrast, an analysis from the NIH-AARP Diet and Health Study; a prospective cohort of older US adults, found that intake of total fructose but not of added sugar was associated with a modest increase in risk of all-cause mortality in men and women [21]. However, total sugars from beverages, including added sugar were positively associated with risk of all-cause, CVD and other-cause mortality in women while only fructose from beverages was positively associated with risk of all-cause and CVD mortality in men.

In 2015, the WHO released guidelines on the intake of free sugars for adults and children [22]. This guideline strongly recommends to reduce the intake of free sugars throughout the life-course. In both adults and children, it is strongly recommended that the intake of free sugars should not exceed 10% of total energy intake. Further reduction to below 5% of total energy intake is a conditional recommendation. The WHO states that the first 2 recommendations are based on the health risks of free sugars consumption in predisposing those who consume them to overweight and obesity, and dental caries. The third recommendation states that a further reduction of free sugars to below 5% (about 6 teaspoons) of total energy intake per day would provide additional benefits. The limits would apply to all sugars added to food, as well as sugars naturally present in honey, syrups, fruit juices and fruit concentrates.

Another argument going against the fact that not only the fructose is harmful involves the glycemic index (GI). This index is a scale of classification of foods rich in carbohydrates according to the rise in blood sugar compared to a reference element, which is glucose or white bread. Glucose and the most commonly consumed starchy foods have a high GI, while fructose has a low GI. In addition, meta-analyses and systematic reviews have linked diets with high GI in the same undesirable effects as those of fructose, particularly regarding obesity and T2DM [8]. It is wrong to believe that there is no risk to consume foods and drinks with added sugars, as long as it is not fructose.

In other words, there is a real risk to consume added sugar. We cannot repeat enough the importance of taking the time to read food labels when shopping to avoid buying products that contain added sugars. We therefore recommend to this patient and her family to choose foods and drinks that contain no added sugar. It is also recommended to avoid the addition of sugar table in drinks, cereals and to reduce the consumption of processed meals (prepared or frozen) that often contain a lot of added sugar and salt.

In other words, there is a real risk to consume added sugar. We cannot repeat enough the importance of taking the time to read food labels when shopping to avoid buying products that contain added sugars. We therefore recommend to this patient and her family to choose foods and drinks that contain no added sugar. It is also recommended to avoid the addition of sugar table in drinks, cereals and to reduce the consumption of processed meals (prepared or frozen) that often contain a lot of added sugar and salt.

To better understand the relationship between the consumption of diet drinks and caloric intake, the researchers looked at almost 24 000 adults of 20 years of age and older and noted the drinks and foods consumed over a period of 24 hours. They found that 11% of adults with a healthy body weight, 19 % of overweight adults and 22 % of obese adults drank diet drinks. The number of calories consumed during that 24 hour period by overweight or obese adults who drank diet drinks was similar in terms of number of calories.

On the other hand, adults with a weight surplus or obese people who drank diet drinks tended to ingest more calories in the form of solid food. Indeed, they have consumed 88 and 194 more calories from solid foods per day, respectively, than similar adult who drank soft drinks. Notably, obese adults who consumed diet drinks ate much more during snacks than those who were exposed to sugary drinks. Those who drank diet drinks consumed 131 calories per day from salty snacks compared to 243 calories from sugary snacks, compared to 107 and 213, respectively, for obese adults who drank sugary drinks.

One of the main reasons for these results is that the consumption of artificial sweeteners present at high doses in diet drinks, is associated with greater activation of the centers of rewards at the brain level, thereby increasing feelings of pleasure a person experiences during the ingestion of sweetened foods [7]. In other words, the consumption of diet drinks artificially sweetened can alter the activity of the receptors responsible for the control of sugar in the brain, causing disturbances in the control of appetite. This results in an increase of food consumption, representing a potential risk of weight gain. Similarly, the increase in the consumption of calories from sweetened snacks rather than salty snacks is compatible with this concept and suggests diet drinks sweetened with natural or artificial sweeteners drinks encourage some form of dependence on sugars [7, 23].

The results of the study from Bleich and colleagues suggest that overweight or obese adults seeking to lose or maintain their weight loss and having already replaced sugary drinks for diet drinks, should look carefully at other solid components of their diet, especially sweet snacks, which would allow them to identify food to change in their diet [23]. Therefore, it is wrong to believe that there is no risk to diet drinks. We do not recommend to totally eliminating diet drinks from the youth diet because they can help control weight due to their low calorie levels especially if they contain no added sugar. However, based on the results presented in the adult, it is also recommended to young people, especially those who are overweight or obese and who drink diet drinks, to become aware of the calories from solid foods, particularly sugary foods, in order to prevent weight gain or facilitate weight loss. It is recommended that patient pay special attention to the choice and content of snacks to ensure that the total and wanted energy intake be respected, even if they consume diet drinks.

It was found that replacement of 1 serving per day of SSBs with one serving of water was associated with 0.49 kg less weight gain over each 4-year period [24]. In the NHS II, substituting water for SSBs was also associated with a significantly lower risk of T2DM [25]. Therefore, this represent a good strategy for our 14 year-old patient, but, unfortunately, I do not think that this strategy will be sustainable at long-term. One hundred percent fruit juice could be perceived as a healthy alternative to SSBs, since juices contain some vitamins and other nutrients. However, fruit juices also contain a relatively high number of calories from natural sugars, with likely greater amounts of fructose. A positive association seems also to exist between the consumption of fruit juice and greater weight gain and T2DM, although some conflicting evidence exists. Nonetheless, based on the current evidence it has been recommended that daily intake of 100 % fruit juices be limited to 4–6 ounces per day [26-28].

(d) the use of sweeteners (artificial sugars) is a good choice

It is often proposed to address the problems associated with the overconsumption of sugar by using artificial sweeteners such as saccharin, acesulfame, aspartame, neotame, stevia (which is a natural plant extract) and others as they contain no calories. On the other hand, these synthetic substances are hundreds to thousands of times sweeter than sucrose and cause an intense feeling of pleasure in the brain with minimal concentrations of artificial sweetener [7]. As suggested by the term “diet”, under which these products are marketed, the food and drinks with artificial sweeteners are supposed to produce a sweet taste comparable to their counterparts containing sugar, but with fewer calories, contributing to weight loss.

Short term clinical trials provide evidence to that effect. For example, an increase in weight and blood pressure and inflammatory markers were observed in obese adults who consumed on average 600 Kcal/d of sucrose, mainly in the form of SSBs, for 10 weeks, compared to a control group using artificial sweeteners [7]. Therefore, it is possible to believe that the use of these artificial sweeteners can have a beneficial effect on weight control. However, the physical mechanisms for maintaining weight are subtle and complex. Now, it is increasingly obvious that the lack of calories from artificial sweeteners would be replaced, over time, with calories from other sources. Thus, this compensation could have an impact on weight control and on health [7]. In addition, increased stimulation of brain receptors by a frequent consumption of these powerful artificial sweeteners can cause taste preferences to sugars which will persist creating an increased tolerance to sugars.

Therefore, people who regularly use these artificial sweeteners can find not sweetened enough some foods such as fruits, vegetables, legumes and other. As these foods have become less attractive, so less consumed, the quality of the diet is reduced, thus contributing to a risk of weight gain. One of the concerns is that the repeated use of these artificial sweeteners can disrupt hormonal ways and neurobehavioral comportments, thus causing a preference for sweet foods, a change in the feeling of hunger, which would affect the control of appetite and, indirectly, the control the weight. Therefore, it is wrong to believe that the use of sweeteners (artificial sugars) is a good choice. Despite the lack of study on the consequences of the sweeteners among young people, it would be preferable that these parents do not give these artificial sweeteners to her 14 year old daughter.

(e) neither is true.

All these answers are false. As discussed by Goran [29-30], children and teens today grow up in a much sweeter nutritional environment than previous generations. A good use of sugary drinks and sugary solids contained in snacks and meals became an important daily task for parents in the education of children and adolescents. Indeed, more than 70% of the foods contain sugar, and the consumption of soft drinks has increased fivefold since 1950.

It is also important to note that the consumption level of sugar is particularly high in vulnerable segments of the population who are more susceptible to obesity, as well as in young people with a low socio-economic status such as ethnic minorities, the obese and other groups. The latest research on this topic has demonstrated a strong link of evidence between the sugar contain in food, particularly fructose and the risk of hepatic steatosis, which has more than doubled in children in the last 10 years [31-32]. Increased consumption of fructose in adolescents was proved to be associated with CVD risks later in life secondary to an increase in abdominal fat [33].

A recent study of Stanhope and his collaborators describes how the metabolism of fructose is associated with a good number of adverse metabolic effects [34]. These effects are likely to be increased during growth and development because fructose promotes differentiation of adipose tissue during growth. In support of this concept, the article of Disse and colleagues shows that children with a disorder of absorption of fructose have lower levels of obesity [35]. Although not definitive, this finding supports the concept of a more damaging effect of fructose on obesity during growth. This concept is also based on the Morgan [36] meta-analysis which shows that the consumption of fructose can contribute to the increase in the prevalence of pediatric obesity, while the limitation of SSBs which include the majority of fructose intake can help to reduce the prevalence of obesity among young people and help to improve their metabolic profile [37].

This imbalance to a greater amount of fructose in the diet has other implications for the growth and development of children and adolescents [29-30]. For example, the consumption of milk, which has declined in favor of SSBs; the milk is now more expensive than SSBs. This has consequences on the daily fructose consumption because milk contains no fructose, while SSBs, is very rich in fructose. For example, a serving of 12 fluid ounces (350 ml) of soft drinks contains 23 g of fructose. Two of these portions would be sufficient to reach 90% of the acceptable level of the daily consumption of fructose for youth, without even taking into account the fructose consumed from other natural sources (fruits and vegetables) and found in the other foods [38].

Despite the diversity of links between increased consumption of SSBs and fructose and obesity among young people, an important conclusion is observed: increased consumption of sugar, particularly fructose, contributes to a profile of altered body fat which would favour an increased risk of metabolic diseases, including T2DM, fatty liver and other [37]. Note a higher level of sugar, especially of dietary fructose induce a metabolic dysfunction, especially among young people who are overweight or obese, compared to young people with normal weight [39]. Youth studies suggest that a reduction in the consumption of SSBs leads to a better weight control among those who are overweight [39].

Despite the mixed conclusions and some gaps in our knowledge about the effects of sugars on obesity and the metabolic risk in pediatric populations, the majority of studies support the current efforts of public health to reduce the total consumption of sugars and fructose in this population [30]. For the reasons given previously, it is a crucial issue among youth because of the underlying effects of added sugar, and fructose on the growth and development of adipose tissue.

The most important is to consider the effects of fructose on the brain and on the appetite control, which are to promote the development of obesity. It is therefore realistic to believe that fructose would have an “obesogenic” effect during the period of development of the youth (30). Since overweight and obesity aggravate the effects of sugar on the metabolic disorders during growth and development, efforts to reduce the sugar consumption should focus on children and adolescents who are overweight or obese. It is also suggested to focus not only on obesity as a consequence, but also as a metabolic risk factor for T2DM and CVD.

From the information above and the lack of clear regulations governing the content in sugar and fructose of several foods and sugary drinks, it seems very justifiable to recommend the absence of SSBs among our young people with overweight or obesity. Remember that, in fruit and vegetables, the fructose is mixed with fibre, vitamins, minerals and enzymes, making it harmless, which justified retaining the current recommendation of five servings of fruits and vegetables per day and no SSBs.

Conclusion

Intake of added sugar, predominantly sucrose and HFCS from SSBs has increased markedly in the US and Canada in the past decades and constitutes the major source of fructose in the diet. In this perspective, and since we rarely consume fructose in isolation, it is logical to measure the potential cardiometabolic effects of fructose by evaluating its associations with SSBs. Although the consumption of SSBs has decreased moderately in recent years, the intake levels remain high in the US and Canadian populations and are increasing rapidly in developing countries.

Based on the available evidence we can conclude that the consumption of SSBs causes excess weight gain and is associated with increased risk of T2DM in adult and pediatric patients. It also increases risk of CVD and other serious health problems later in life. SSBs are thought to promote weight gain in part due to excess calories and incomplete compensation for liquid calories at subsequent meals. These beverages may also increase T2DM and CVD risk independently through an adverse glycemic response and unique metabolic effects of fructose. Short-term mechanistic studies have shown that excess fructose ingestion can result in additional cardiometabolic effects due to increased hepatic de novo lipogenesis, accumulation of visceral adiposity and ectopic fat and production of uric acid [2].

Several public policy and regulatory strategies to reduce intake of SSBs have been in place or are being considered to limit the consumption of SSBs. Implementing and evaluating such policies are important areas for scientists and policymakers. Key areas that warrant future research include examining the effects of different sugars and sugar moieties on health outcomes over a broad range of doses, investigating the health effects of sugar consumed in solid form in comparison to liquid sugar and further elucidating the biological mechanism by which intake of liquid calories induces an incomplete compensatory intake of energy at subsequent meals. There is also a need to identify effective strategies to reduce SSB consumption at the individual and population level. In this regard the Canadian Diabetes Association recommends the following in its Sugar Position Statement for the population and the Government [40].

The Canadian Diabetes Association recommends Canadians:

1. Limit intake of free sugars a to less than 10% of total daily calorie (energy) intake. This is approximately 50g (12 teaspoons) of free sugars consumption per day based on a 2000 calorie diet.

2. Limit intake of sugar sweetened beverages (SSB) and drink water in its place.

3. Promote intake of whole foods and reduce intake of free sugars throughout life for overall health.

The Canadian Diabetes Association recommends that:

1. The Government of Canada introduce a tax on SSBs and use the revenues generated to promote the health of Canadians.

2. The Government of Canada ensures clear nutrition labelling for packaged foods including the amount of free sugars on the Nu-trition Facts Table.

3. Federal, Provincial and Territorial Governments immediately operationalize the World Health Organization (WHO) set of rec-ommendations to prevent the marketing of foods and beverages to children.

4. A Federal, Provincial and Territorial Working Group on Food and Beverage Marketing to Children is convened to develop, im¬plement and monitor policies to restrict food and beverage mar¬keting to children.

5. Federal, Provincial and Territorial governments support im¬proved access to and affordability of nutritious foods in all re¬gions.

6. The Government of Canada implement legislation to require la¬beling of free sugars on menu labels in restaurants so Canadians can make more informed choices about the foods they eat.

7. Recreational events, schools, recreation facilities, and govern¬ment spaces not offer SSBs for purchase.

8. Recreational events, schools, recreation facilities, and govern¬ment spaces provide free water for consumption.

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Is there a definition of Metabolically Healthy Obese Pediatric Patients?

Letter to the editor

We have clearly explained in the first articles of this special issue that pediatric obesity increases the risk for metabolic diseases, including T2DM, HTN, dyslipidemia and many other chronic disorders. We have also explained that pediatric obesity is associated with the risk of developing cardiovascular disease (CVD) later in life. However, it is also clear that not all obese pediatric patients develop these disorders. Therefore we have a clear evidence that a unique subset of obese pediatric patients who appear to be protected from the development of metabolic disturbances and CVD. In adults, Plourde and Karelis have been able to provide a definition of a subgroup of adult obese patients considered as metabolically healthy obese (MHO) [1].

This definition is now used internationally under the term of (PK definition; Plourde and Karelis definition) and is used to determine the prevalence of MHO vs the prevalence of metabolically unhealthy obese patients (MUHO) [2]. As in adults, identifying obese pediatric patients with this potential protective profile could help us determine which part of the obese pediatric population needs to be only periodically observed and which needs to have early therapeutic interventions [1]. However, as in adults important questions on the MHO profile remain unanswered: do we have consensus on the definition and do they remain metabolically healthy over the course of their lifetime?

Obviously, for the purpose of this article, we will limit our discussion to the adolescent age group i.e., those more at risk of developing T2DM. We limit to this age group for the purpose of being more easily able to compare to the adult population. Also because many questions still remained to be answered having different age group will increase difficulties finding an appropriate definition of MHO. We will not be able to get definitive answers to the questions raised, but we hope that this letter will generate scientific discussion around the topic of pediatric patients with MHO.

Identifying MHO individuals

Adults defined as MHO are characterized for their low metabolic abnormalities such as: insulin resistance (IR), pro-atherogenic lipoprotein profile, pro-inflammatory state, or hypertension. In addition, they present lower visceral, hepatic, muscle fat accumulation and gene expression-encoding markers of adipose cell differentiation [3]. However, it is important to note that MHO individuals may also have multiple intermediate metabolic risk factors that may signal increased risk for T2DM and CVD (3). In general, insulin sensitivity indices and a cluster of metabolic risk factors (i.e. blood pressure, triglycerides, HDL-cholesterol and glycaemia) with specific thresholds are used in the identification of MHO subjects.

As discussed in the review by Plourde and Karelis [1], the complexity of techniques to determine insulin sensitivity and the use of different surrogate indexes to determine metabolic risk factors has led to different definitions of MHO. Therefore, without an expert consensus on the definition of MHO patients, findings and/or conclusions on MHO subjects are difficult to interpret. Accordingly, we considered appropriate to provide simple clinical criteria for the identification of MHO individuals.

We first believed that waist circumference of ≥80 cm for women and ≥94 cm for men should be used to identify adults MHO subjects instead of a BMI of ≥30 kg/m2. We then suggested the following metabolic markers with their cut-points: glycemia <5.6 mmol/l, HDL ≥1.3 mmol/l for women and ≥ 1.03 mmol/l for men, triglycerides <1.7 mmol/l, and blood pressure <120/80 mm Hg. The proposed choice of these clinical markers was based from the criteria for the identification of the metabolic syndrome in adults from the International Diabetes Federation [5]. It should be noted that the cut-point for blood pressure was set at <120/80 mmHg since there is evidence to suggest that pre-hypertension may increase the risk of cardiovascular disease [6]. We propose that adults MHO individuals may be identified when all four of the metabolic markers are met. We seek to apply a strict method because our goal is to identify a “true” MHO population which could be different from a non-metabolic syndrome population.

We feel this represents a good first step for a consensus of a standard definition for MHO individuals. We understand that this definition is open to criticism and that the list of criteria could be modified and that the cut-points may be refined. However, according to Truthmaan J et al, (2016) [2], the PK criteria, which define MHO by the fulfilment of all included PK criteria may be more appropriate to determine a “true” MHO. However, in the adolescent age group, it seems that the definition of abdominal obesity is particularly lacking and need to be challenged by the medical and scientific community.

Potential definition for MHO adolescent

In a recent study performed in a district school in Bangladesh they assess the prevalence of obesity and abdominal obesity by means of body mass index (BMI) and waist-to-height ratio (WHtR), respectively, in adolescent girls [7]. Based on age and sex specific BMI percentiles, the students were classified as normal weight (5th– <85th percentile), overweight (85th–<95th percentiles), and obese (≥95th percentile). Central obesity was categorized as WHtR ≥ 0.5. Adolescent girls (aged 9–17 years) attending the sixth to twelfth grades (n = 501) in a Bengali medium school participated in the study. The prevalence of obesity and overweight were 23% and 14% among the girls. The prevalence of central obesity was 26%. Around 14% of girls in the normal weight group were centrally obese. Which reinforce the rationale for measuring abdominal obesity in adolescents? There was a significant relationship between WHtR and BMI status (P = 0.0001) [7].

The importance of measuring waist circumference is strongly supported by the results of the 2007–2009 Canadian Measures Health Survey where 2.6% of adults with normal weight, 35.3% of adults with overweight and 93.0% of adults with obesity had waist circumferences suggesting abdominal obesity [8]. Furthermore, although BMI data suggest that 24% of Canadian adults are at high risk for obesity-related illness or death, 37% of Canadian adults are at high risk when waist circumference is taken into consideration [8]. Thus, using both measures increases the threshold for identifying patients at risk for health problems and as mentioned above, adolescent are not different on that aspect [7]. Therefore, the risks for all medical conditions associated with obesity increase with higher BMIs and larger waist circumferences in both adults and adolescent patients [7, 9].

The current International Diabetes Federation definition of metabolic syndrome in pediatric patients recommends the use of WC as a mandatory diagnostic component [10]. Evidence suggested that compared to general obesity, abdominal obesity is associated with greater cardiovascular risks. Recently, the use of BMI as a cardiovascular risk factor has been questioned and WC received increasing attention in clinical practice [10]. Considering the high prevalence of pediatric obesity, we suggest that more attention should be paid to the monitoring aspects of abdominal obesity among children and adolescents and that prevention strategies should be more focused on abdominal obesity [11].

According to the IDF [10, 12], in adolescent ages 10 to 16 years-old, MUHO is defined as: abdominal obesity with the ≥90th percentile for age and sex (or adult cut-off if lower) as assessed by waist circumference; triglycerides ≥1.7 mmol/L; HDL-cholesterol <1.03 mmol/L; Blood pressure ≥130 mm Hg systolic or ≥85 mm Hg diastolic and Glucose ≥5.6 mmol/L (oral glucose tolerance test recommended) or known T2DM.

For the adolescent aged higher than 16, it is recommended to use the existing criteria for adults. Accordingly, we considered appropriate to provide the same clinical criteria for the identification of adults with MUHO. We first retain the same waist circumference of ≥80 cm for women and ≥94 cm that we used to identify adults MUHO subjects [1]. We then suggest the following metabolic markers with their cut-points: glycemia <5.6 mmol/l, HDL ≥1.3 mmol/l for girls and ≥ 1.03 mmol/l for boys, triglycerides <1.7 mmol/l, and blood pressure <120/80 mm Hg. I believe that, at this point, that this definition is the best definition of MHO especially considering that being obese at a young age and for a longer period of time is associated with a high risk of T2DM and CVD risk factors later in life (see article # 2). However, we do not think that this one is the final definition of pediatric MHO and again we hope that the scientific community will be open to discuss this definition.

Conclusion

As in adults, data on the lifestyle profile of adolescents MHO subjects is rather limited. Indeed, there is evidence to suggest that physical activity levels and the dietary profile of MHO individuals are not similar to MUHO subjects [1]. Thus, currently, it is difficult to elaborate on relevant clinical practice guidelines for both surveillance and treatment of MHO patients. There is no evidence that these subjects are permanently protected from the risk of developing obesity, T2DM and their related comorbidities. Also, adolescent MHO individuals may present other obesity-related comorbidities such as sleep apnea, knee osteoarthritis, poorer body image and many others comorbidities. Moreover, there is no evidence that MHO adolescents could tolerate a further increase of their fat mass, without any consequences on their cardio-metabolic profile as it is well established that worsening of body weight is strongly associated with the deterioration of risk factors for CVD [13]. Therefore, on the basis of this evidence or until future evidence can state otherwise, a prudent attitude would be to regularly monitor cardio-metabolic risk factors in obese adolescent MHO patients (especially elevated triglycerides, glycaemia, HOMA and C-reactive protein as well as low HDL), in order to detect as early as possible a negative evolution of their cardio-metabolic profile as recommended in the Clinical Practice Guidelines for the Management of Obesity [14]. In particular, a special surveillance should be applied to prevent any increase in body weight, and waist circumference (WC) as it was previously concluded that the MHO phenotype may be maintained by promoting lower WC [15]. Furthermore, it seems difficult to prescribe the optimal weight loss program in MHO individuals since the potential benefits of a weight loss treatment are still a matter of debate. Studies assessing the effects of lifestyle interventions, including diet and/or physical activity in MHO have led to divergent results [1]. Thus, we would suggest that prioritization for weight loss treatment may be given to MUHO patients. Achieving permanent weight reduction is a difficult challenge for any obese person and the risk of weight regain is elevated. For this reason, any weight loss program in MHO individuals should be preceded by a careful evaluation of expected resources, costs and benefits. However, for all obese patients including adolescents our public health message should remain the same about promoting good lifestyle habits and prevention of weight gain.

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