Evolution of body mass index in children with type 1 diabetes mellitus.

The prevalence of childhood overweight and obesity has risen during the last 30 years, not only in children with type 2 diabetes, but also those with type 1 (T1D) and this is linked with an increased cardiovascular risk. A better understanding of weight patterns in the years after diagnosis of T1D is important to identify those children with a risk for excess weight gain and strategies to decrease this. We retrospectively analyzed data of all children with T1D followed at the department of Pediatric Endocrinology Leuven and diagnosed between 1991 and 2015. Data as age, sex, BMI, and Tanner score were extracted in 390 subjects. Standardized BMI (BMI SDS) in this study group using all data was 0.26. An increase in BMI SDS was seen as a function of time since diagnosis and age, both being independent predictors. Data comparison showed a significant stronger relation between BMI SDS and both time since diagnosis and age in girls. Children diagnosed after puberty showed a higher increase in BMI SDS.Conclusion: These longitudinal data suggest an important increase in BMI in children with T1D, both as a function of time since diagnosis and age, especially in girls. What is Known: • The prevalence of childhood overweight and obesity is risen during the last 30 years, in children with type 2 diabetes, but also those with type 1 diabetes. What is New: • Our study demonstrates with longitudinal data an increase in BMI in children with type 1 diabetes, especially girls. The increase in BMI SDS is seen as a function of time since diagnosis and age, both being independent predictors. Given the increased risk of metabolic syndrome and other complications in overweight children, special attention is needed to prevent this evolution.