New research published in the journal Diabetologia and presented this year at the annual meeting of the American Diabetes Association in New Orleans, Louisiana, USA, shows that excessively high body mass index (BMI) in adolescents is associated with the development of type 1 diabetes (a form of the disease more associated with autoimmune complications), and not just the type 2 form commonly associated with overweight. The authors of the study are Professor Gilad Twig, Sheba Medical Center, Israel, and his colleagues.
Type 1 diabetes is traditionally called childhood diabetes, occurring in children of any age and weight, although it can also develop during adolescence and adulthood. However, the rapidly growing epidemic of diabetes now occurring in almost all countries consists mainly of cases of type 2 diabetes associated with risk factors such as obesity/overweight, physical inactivity and sedentary lifestyle.
More recently, studies in young children have reported an association between an increase in BMI and the risk of developing type 1 diabetes, but data for late adolescence are limited. This is of interest because approximately 50% of cases of type 1 diabetes develop after late adolescence (beginning at age 18). In a new study, the authors analyzed the association between BMI in late adolescence and the onset of type 1 diabetes in young adulthood.
This nationwide study included all Israeli adolescents aged 16-19 who underwent a medical examination in preparation for mandatory military conscription between January 1996 and December 2016, as long as they had no history of abnormal blood sugar levels. . A total of 1.46 million adolescents were included. The data were linked to information on the onset of type 1 diabetes in adults in the Israeli National Diabetes Registry. Weight and height were measured at study entry, and statistical modeling was used to calculate the excess risk of type 1 diabetes associated with being overweight or obese.
During 15,819,750 person-years of follow-up (median age at diagnosis 25 years), 777 new cases of type 1 diabetes were reported. BMI has been found to be associated with the onset of type 1 diabetes. In a model adjusted for age, sex, and sociodemographic variables, the increased risk of developing type 1 diabetes increased as BMI increased.
Compared with adolescents with an optimal BMI (5th-49th percentiles of BMI for age and sex, according to the US Centers for Disease Control and Prevention), obese adolescents (≥95th percentiles) were twice as likely to develop type 1 diabetes. higher, and overweight adolescents (85th-94th percentiles of BMI) had a 54% increased risk of developing type 1 diabetes. A slight increased risk (41%) was observed with BMI values above normal (75-84th BMI percentile). For the entire BMI range, the authors reported that for every 5 kg/m2, the adjusted risk of developing type 1 diabetes increased by 35%.
The authors discuss that there is increasing evidence of an association between obesity and various autoimmune diseases. The possible explanation they provide is that increased levels of inflammatory adipokines and cytokines associated with obesity reduce self-tolerance, promoting pro-inflammatory processes that lead to diabetes.
“Additional factors associated with obesity may contribute to the development of autoimmunity, including vitamin D deficiency, consumption of a high-fat diet, and modulation of the gut microbiota. Given that there was an association between adolescent obesity and type 1 diabetes in our cohort, even when excluding those with already existing autoimmune diseases, additional factors may link obesity specifically to type 1 diabetes.”