Overweight, Obesity in Adolescence Could Raise Type 1 Diabetes Risk in Adulthood

Gilad Twig, MD, PhD

New research presented at the American Diabetes Association 82nd Scientific Sessions suggests adolescent obesity could increase risk of type 1 diabetes in young adulthood.

Although typically associated with increased risk of type 2 diabetes, the study leveraged data from more than 1.4 million adolescent patients and found an increased risk of type 1 diabetes among adolescents with overweight and obesity, with a graded increase for type 1 diabetes observed across BMI categories.

“Our findings have public health implications. The prevalence of adolescent obesity is rising worldwide at an alarming rate, with dire projections for the near future,” wrote investigators.

Led by Gilad Twig, MD, PhD, of Tel Aviv University, along with colleagues from other Israel-based institutions and Canada, the study was designed to estimate potential associations between BMI in late adolescence and incident type 1 diabetes in late adulthood. With this in mind, investigators designed their study as a retrospective cohort study using data from a pair of data sources aggregating information from patients in Israel. The first database provided investigators with information on all Israeli adolescents ages 16-19 years, unless they had a history of dysglycemia, who underwent medical valuation in mandatory military conscription from 1996-2016. The second database was the Israeli National Diabetes Registry, which investigators used to assess the incidence of adult-onset type 1 diabetes.

The primary outcome of interest for the investigators’ analysis was the incident of type 1 diabetes, which was defined as use of short-acting insulin that was initiated within 1 year of diabetes onset without the prescription of other antiglycemic properties. For the purpose of analysis, weight and height at age 17 were used in the investigators’ Cox proportional hazards model, which assessed BMI as both a categorical and continuous variable.

Overall, investigators obtained data related to 1,426,362 individuals without type 1 diabetes in adolescence and a total of 777 incident cases of type 1 diabetes during 15,810,751 person-years of follow-up. Investigators pointed out the mean age at diagnosis among these patients was 25.2±3.9 years and initial analysis indicated BMI was associated with incident type 1 diabetes.

In models adjusted for age, sex, and sociodemographic variables, a graded increase in risk was observed across BMI categories. Specifically, the hazard ratios for incident type 1 diabetes were 1.05 (95% CI 0.87-1.27) for the 50th to 74th BMI percentiles, 1.41 (1.11-1.78) for the 75th to 84th BMI percentiles, 1.54 (1.23-1.94) for adolescents with overweight, and 2.05 (95% CI, 1.58-2.66) for adolescents with obesity. Of note, overweight was considered a BMI in the 85th to 94th percentiles and obesity was considered being among the 95th percentile or greater. Further analysis suggests a single standard deviation increase in BMI was associated with a 25% increase in risk of type 1 diabetes (HR, 1.25 [95% CI, 1.17-1.32]).

“Our study adds to the growing evidence regarding the health hazards associated with adolescent obesity. Not only is adolescent obesity correlated with adult-onset of type 2 diabetes as previously reported, but also with type 1 diabetes,” investigators noted. “Further work needs to be done to unravel this association so that we can better address the full spectrum of risks posed by the obesity epidemic or identify common environmental factors affecting both weight and type 1 diabetes.”

This study, “Obesity in late adolescence and incident type 1 diabetes in young adulthood,” was presented at ADA 2022 and published in Diabetologia.