Polymorphism of the FTO Gene Influences Body Weight in Children with Type 1 Diabetes without Severe Obesity

Drawing lines in the sand: The growing threat of obesity in type 1 diabetes

In this editorial, we comment on the article by Zeng et al published in the recent issue of the World Journal of Diabetes in 2024. We focus on the epidemiological, pathophysiological, and clinical interplay between obesity and type 1 diabetes mellitus (T1DM). Overweight and obesity represent a growing threat for modern societies and people with T1DM could not be an exception to this rule. Chronic exogenous insulin administration, genetic and epigenetic factors, and psy-chosocial and behavioral parameters, along with the modern way of life that incorporates unhealthy eating patterns and physical inactivity, set the stage for the increasing obesity rates in T1DM. As our knowledge of the underlying mechanisms that lead to the development of obesity and hyperglycemia expands, it becomes clear that there are overlap zones in the pathophysiology of the two main types of diabetes. Stereotypes regarding strict dividing lines between "autoimmune" and "metabolic" phenotypes increase the risk of trapping physicians into ineffective therapeutic approaches, instead of individualized diabetes care. In this context, the use of adjuncts to insulin therapy that have the potential to alleviate cardiorenal risk and decrease body weight can reduce the burden of obesity in patients with T1DM.

Associations of the obesity gene FTO variant with complications and comorbidities in patients with type 1 diabetes

BACKGROUND AND AIMS

Because FTO gene is connected with the risk of obesity, cardiovascular disease and hypertension, as well as type 2 diabetes, we hypothesize that the rs9939609 FTO polymorphism may affect type 1 diabetes (T1D) complications and comorbidities.

METHODS

We have investigated the associations of the FTO gene variant with the T1D and its complications and comorbidities, as well as the serum levels of pro- and anti-inflammatory markers and lipid profiles.

RESULTS

The key results of our study are as follows: (1) the rs9939609 FTO polymorphism does not predispose individuals to T1D; (2) AA genotype is associated with an increased risk of overweight and obesity, retinopathy, hypertension, dyslipidemia and celiac disease; (3) AT genotype is associated with a decreased risk of retinopathy and celiac disease, whereas TT genotype is connected with decreased risk of dyslipidemia; (4) the FTO rs9939609 polymorphism affects the inflammatory status as well as lipid profile in T1D patients.

CONCLUSIONS

Our results, for the first time, comprehensively indicate that the rs9939609 FTO polymorphism could be considered a genetic marker for increased susceptibility to T1D complications and comorbidities as well as suggests importance of FTO-mediated pathways in their etiology.

Evaluation of the role of FTO (rs9939609) and MC4R (rs17782313) gene polymorphisms in type 1 diabetes and their relation to obesity

OBJECTIVES

This study aims to explore the effects of fat mass obesity-associated (FTO) (rs9939609) and melanocortin 4 receptor (MC4R) (rs17782313) gene polymorphisms in children with type 1 diabetes (T1D) and their relation to obesity.

METHODS

Fat mass obesity-associated (FTO) (rs9939609) and melanocortin 4 receptor (MC4R) (rs17782313) gene polymorphisms were evaluated in 164 patients and 100 controls, and genotypes, alleles, and haplotype frequencies were compared between cases and controls.

RESULTS

A significant association with T1D development was found with the TC, CC, and TC+CC genotypes and the C allele of MC4R rs17782313. In addition, TA, AA, and TA+AA genotypes and the A allele of FTO rs9939609 may also be risky for T1D development. While the TC and TC+CC genotypes of MC4R rs17782313 may be protective against obesity development, the AA genotype and A allele of FTO rs9939609 may also be protective against obesity development. Regarding obese subjects, comparing diabetics vs. non-diabetic studied subjects, FTO rs9939609, TA, AA, and TA+AA genotypes and the A allele had significantly higher frequencies in T1D with a higher risk of developing T1D. However, conducting multivariable analysis using significant covariates in univariable analysis revealed that only earlier age of T1D onset, lower C-peptide, and the MC4R dominant model were considered independent predictors of obesity within T1D.

CONCLUSIONS

The role of both genes' polymorphisms on the pathogenesis and the outcome of T1D and obesity can help in understanding the pathogenesis of both diseases and their associations with each other's and may be used as novel therapeutic targets for both diseases.

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 Double Whammy of Obesity and Diabetes on Female Reproductive Health

The rising global prevalence of obesity and diabetes, especially in youth, confers substantial metabolic consequences and increased mortality in affected individuals. While obesity is strongly tied to the development of insulin resistance and type 2 diabetes, emerging evidence shows that obesity rates are also increasing exponentially in those with type 1 diabetes, contributing to insulin resistance and cardiometabolic sequelae. In addition, both obesity and diabetes can exert adverse effects on female reproductive health independently, with the presence of both conditions likely to exacerbate reproductive dysfunction in this cohort. If the current trends in obesity and diabetes incidence persist, it is likely that more women will be at risk of obesity- and diabetes-related reproductive disorders. This review aims to describe the epidemiology and mechanisms of obesity in women with diabetes, and summarize current literature regarding reproductive disorders in diabetes and weight management strategies in this cohort.

Anthropometric and Metabolic Responses in FTO rs9939609 Gene Polymorphism after a Multidisciplinary Lifestyle Intervention in Overweight and Obese Adolescents

Few studies show the potential changing effect of fat-mass and obesity-associated ( FTO ) rs9939609 gene on cardiometabolic risk after a lifestyle intervention. This study aims to evaluate whether overweight and obese adolescents, carriers of the risk genotypes for obesity of the FTO rs9939609 gene polymorphism, have different anthropometric and biochemical responses to an interdisciplinary intervention program. The quasi-experimental study involved 34 adolescents aged 10 to 15 years. Schoolchildren with AA/AT genotype decreased glucose, total cholesterol, low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol. However, there were no differences between the genotypes, suggesting that the "A" allele did not modify the subject's response to the intervention program.

Obesity in Type 1 Diabetes: Pathophysiology, Clinical Impact, and Mechanisms

There has been an alarming increase in the prevalence of obesity in people with type 1 diabetes in recent years. Although obesity has long been recognized as a major risk factor for the development of type 2 diabetes and a catalyst for complications, much less is known about the role of obesity in the initiation and pathogenesis of type 1 diabetes. Emerging evidence suggests that obesity contributes to insulin resistance, dyslipidemia, and cardiometabolic complications in type 1 diabetes. Unique therapeutic strategies may be required to address these comorbidities within the context of intensive insulin therapy, which promotes weight gain. There is an urgent need for clinical guidelines for the prevention and management of obesity in type 1 diabetes. The development of these recommendations will require a transdisciplinary research strategy addressing metabolism, molecular mechanisms, lifestyle, neuropsychology, and novel therapeutics. In this review, the prevalence, clinical impact, energy balance physiology, and potential mechanisms of obesity in type 1 diabetes are described, with a special focus on the substantial gaps in knowledge in this field. Our goal is to provide a framework for the evidence base needed to develop type 1 diabetes-specific weight management recommendations that account for the competing outcomes of glycemic control and weight management.

The rs1527483, but not rs3212018, CD36 polymorphism associates with linoleic acid detection and obesity in Czech young adults

Recent evidence has raised the possibility of the existence of a sixth taste modality – that is, taste for fat – which is mediated by lingual CD36 and plays a role in obesity. Consequently, the genetic polymorphism of CD36 has been shown to be associated with altered oro-sensory detection of dietary lipids. In the present study, we investigated the relationship between oro-sensory perception of linoleic acid (LA), two CD36 polymorphisms (rs1527483 and rs3212018), obesity parameters and craving habits for dietary lipids in young Czech adults. We also sequenced 5 and 6 exons of CD36 to trace out any new mutation that might be responsible for the difference in taste perception. We observed that craving for dietary lipids was correlated with anthropometric parameters (P<0·05) and LA detection threshold (P=0·033). The participants with the CC genotype of the rs1527483 polymorphism had lower BMI (P=0·011), waist circumference (P=0·005), waist:height ratio (P=0·010) and higher sensitivity for LA (P=0·037) than the participants with the CT and TT genotypes. Interestingly, we did not observe any association between the rs3212018 polymorphism and the studied parameters. Moreover, we did not observe any mutation in exons 5 and 6 of the CD36 gene in these subjects. Finally, we can state that rs1527483, but not rs3212018, is associated with high body weight in young Czech subjects.

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.

Nutrigenomics: A controversy

Nutrigenomics is an emerging science which investigates a certain area of nutrition that uses molecular tools to search access and understand the several responses obtained through a certain diet applied between individual and population groups. The increased need for the use of personalised nutrition in patients is increasing and research is being made on its possible effects. However, research on nutrigenomics and in particular, obesity is still ongoing. Following a current metanalysis on thirty-eight nutrigenomics genes, it seems that a definite association between the genes usually examined in nutrigenomics testing and several diet-related diseases is lacking, even though there is a limited number of studies associating them. In 2014, literature search results in a great number of studies on several polymorphisms. This heterogeneity could only show the way towards new research aims. Nutrigenomics was born due to the need to move from Epidemiology and Physiology to Molecular Biology and Genetics. Currently, there are steps that need to be considered in order for nutrigenomics to be applied: the genes, the gene/protein network, and the strategy towards the determination of the nutrients' influence on gene/protein expression. It is certainly an interesting evolving science with many areas to be investigated further and from different perspectives, as it involves ethics, medicine, genetics and nutrition.