Disease associated clinical factors and FTO polymorphism: effect on body mass in children with type 1 diabetes mellitus

Polymorphisms of Fat Mass and Obesity-Associated Gene in the Pathogenesis of Child and Adolescent Metabolic Syndrome

Childhood metabolic syndrome (MetS) is prevalent around the world and is associated with a high likelihood of suffering from severe diseases such as cardiovascular disease later in adulthood. MetS is associated with genetic susceptibility that involves gene polymorphisms. The fat mass and obesity-associated gene (FTO) encodes an RNA N6-methyladenosine demethylase that regulates RNA stability and molecular functions. Human FTO contains genetic variants that significantly contribute to the early onset of MetS in children and adolescents. Emerging evidence has also uncovered that FTO polymorphisms in intron 1, such as rs9939609 and rs9930506 polymorphisms, are significantly associated with the development of MetS in children and adolescents. Mechanistic studies reported that FTO polymorphisms lead to aberrant expressions of FTO and the adjacent genes that promote adipogenesis and appetite and reduce steatolysis, satiety, and energy expenditure in the carriers. The present review highlights the recent observations on the key FTO polymorphisms that are associated with child and adolescent MetS with an exploration of the molecular mechanisms underlying the development of increased waist circumference, hypertension, and hyperlipidemia in child and adolescent MetS.

Do sex differences in paediatric type 1 diabetes care exist? A systematic review

AIMS/HYPOTHESIS

Sex differences are present in cardiovascular care and in outcomes among adults with type 1 diabetes mellitus, which typically commences in childhood. Whether sex influences care and outcomes in childhood is not known. This systematic review provides an overview of sex differences in children with type 1 diabetes, focusing on patient and disease characteristics, treatment, comorbidities and complications.

METHODS

Literature in MEDLINE up to 15 June 2021 was searched, using the terms diabetes mellitus, sex characteristics, sex distribution, children and/or adolescents. All primary outcome studies on children with type 1 diabetes that mentioned a sex difference in outcome were included, with the exception of qualitative studies, case reports or case series. Studies not pertaining to the regular clinical care process and on incidence or prevalence only were excluded. Articles reporting sex differences were identified and assessed on quality and risk of bias using Joanna Briggs Institute critical appraisal tools. Narrative synthesis and an adapted Harvest plot were used to summarise evidence by category.

RESULTS

A total of 8640 articles were identified, rendering 90 studies for review (n=643,217 individuals). Studies were of observational design and comprised cohort, cross-sectional and case-control studies. Most of the included studies showed a higher HbA_1c in young female children both at diagnosis (seven studies, n=22,089) and during treatment (20 out of 21 studies, n=144,613), as well as a steeper HbA_1c increase over time. Many studies observed a higher BMI (all ages, ten studies, n=89,700; adolescence, seven studies, n=33,153), a higher prevalence of being overweight or obese, and a higher prevalence of dyslipidaemia among the female sex. Hypoglycaemia and partial remission occurred more often in male participants, and ketoacidosis (at diagnosis, eight studies, n=3561) and hospitalisation was more often seen in female participants. Most of the findings showed that female participants used pump therapy more frequently (six studies, n=211,324) and needed higher insulin doses than male participants. Several comorbidities, such as thyroid disease and coeliac disease, appeared to be more common in female participants. All studies reported lower quality of life in female participants (15 studies, n=8722). Because the aim of this study was to identify sex differences, studies with neutral outcomes or minor differences may have been under-targeted. The observational designs of the included studies also limit conclusions on the causality between sex and clinical outcomes.

CONCLUSIONS/INTERPRETATION

Sex disparities were observed throughout diabetes care in children with type 1 diabetes. Several outcomes appear worse in young female children, especially during adolescence. Focus on the cause and treatment of these differences may provide opportunities for better outcomes.

REGISTRATION

This systematic review is registered in PROSPERO (CRD42020213640).

Highlighting the Role of Obesity and Insulin Resistance in Type 1 Diabetes and Its Associated Cardiometabolic Complications

PURPOSE OF REVIEW

This narrative review appraises research data on the potentially harmful effect of obesity and insulin resistance (IR) co-existence with type 1 diabetes mellitus (T1DM)-related cardiovascular (CVD) complications and evaluates possible therapeutic options.

RECENT FINDINGS

Obesity and IR have increasingly been emerging in patients with T1DM. Genetic, epigenetic factors, and subcutaneous insulin administration are implicated in the pathogenesis of this coexistence. Accumulating evidence implies that the concomitant presence of obesity and IR is an independent predictor of worse CVD outcomes. The prevalence of obesity and IR has increased in patients with T1DM. This increase can be partly attributed to general population trends but, additionally, to iatrogenic weight gain caused by insulin treatment. This association might be the missing link explaining the excess CVD burden observed in patients with T1DM despite optimal glycemic control. Data on newer agents for type 2 diabetes mellitus (T2DM) treatment are unraveling novel ways to challenge this aggravating coexistence.

The influence of clinical and genetic factors on the development of obesity in children with type 1 diabetes

The exact cause of the obesity epidemic remains unknown; however, both environmental and genetic factors are involved. People at risk of developing obesity include children with type 1 diabetes mellitus (T1DM), which in turn increases their cardiovascular disease risk. Here, we discuss the clinical and genetic factors influencing weight in patients with T1DM. In children with T1DM, the presence of obesity depends mainly on sex, metabolic control, and disease duration. However, genetic factors, including the fat mass and obesity-associated (FTO) gene, are also associated with body weight. Indeed, children with the FTO gene rs9939609 obesity-risk allele (homozygous = AA or heterozygous = AT) are predisposed to a higher body mass index and have a greater risk of being overweight or obese. However, in this review, we show that FTO gene polymorphisms only have a small effect on body weight in children, much weaker than the effect of clinical factors. The association between FTO gene polymorphisms and body weight is only statistically significant in children without severe obesity. Moreover, other genetic factors had no effect on weight in patients with T1DM, and further research involving larger populations is required to confirm the genetic basis of diabetes and obesity. Therefore, identifying the clinical features of children with T1DM, such as their initial body mass index, sex, metabolic control, and disease duration, will still have the strongest effect on reducing risk factors for cardiovascular diseases. Physicians should pay close attention to modifiable elements of these relationships, for example, metabolic control and energy and insulin intake, when caring for patients with T1DM. Copyright © 2016 John Wiley & Sons, Ltd.

Organ-specific autoimmunity in relation to clinical characteristics in children with long-lasting type 1 diabetes

BACKGROUND

The aim of this study was to assess the prevalence of diabetes and other organ-specific autoantibodies (Ab) associated with various autoimmune conditions, in Polish children with type 1 diabetes mellitus (T1DM).

METHODS

In this study 114 patients, aged 13.4 years, with mean diabetes duration 5.2 years were included. Ab to islet cell antigens: glutamic acid decarboxylase (GAD), insulinoma antigen 2 (IA-2), zinc transporter 8 (ZnT8), together with thyroid peroxidase Ab (TPO Ab), thyroglobulin Ab (Tg Ab), tissue transglutaminase Ab (tTG Ab) and 21-hydroxylase Ab (21-OH Ab) were measured.

RESULTS

The prevalence of at least one diabetes associated Ab was found in 87%, with the highest prevalence of 64% for ZnT8 Ab. In patients with disease duration <5 years, at least one antibody was present in 90%, the most prevalent was ZnT8 Ab (72%). In patients with duration >10 years, 50% had at least one antibody. The prevalence of other than islet cell autoimmunity was high (34%). Thyroid Ab were detected in 26% patients, 42% in girls vs. 8% in boys, p<0.001. tTG Ab were found in 11% patients, with a greater prevalence in children with early onset (p=0.01). 21-OH Ab were found in 2.6% T1DM patients.

CONCLUSIONS

Islet Ab were found in most T1DM children and remained positive even 10 years after onset. ZnT8 Ab emerged as an important marker for the diagnosis of T1DM in the Polish children. Screening for non-diabetes Ab in T1DM may be helpful in identifying subclinical cases of autoimmune thyroid, celiac or Addison's disease (AD).