Increasing secular trends in height and obesity in children with type 1 diabetes: JSGIT cohort

BACKGROUND: Recently, anthropometric indices in children with type 1 diabetes mellitus (T1DM) have begun to change. OBJECTIVE: To examine secular trends in patients’ anthropometric indices. SUBJECTS: Japanese children with T1DM from the 1995, 2000, 2008 and 2013 cohorts of The Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes. METHODS: We analysed serum haemoglobin A1c (HbA1c) levels, the incidence of severe hypoglycaemic events, the types and doses of insulin, height standard deviation scores (SDS), body mass index (BMI) percentiles compared with healthy Japanese children and obesity prevalence over time. We also stratified the patients according to glycaemic control levels of <58 mmol/mol (optimal), 58–75 mmol/mol (suboptimal) and ≥75 mmol/mol (high-risk). RESULTS: Data for 513–978 patients from each of the cohorts were analysed. The incidence of severe hypoglycaemic events decreased over time (from 21 to 4.8/100 patient-years), while the proportion of insulin analogue doses increased (14.6% to 98.6%). In addition, patient height SDS (−0.22 to +0.17), BMI percentile (52.1 to 58.7) and obesity prevalence (2.1% to 5.1%) increased. Height SDS increased in all of the glycaemic control subgroups, while BMI percentile and obesity prevalence increased in the suboptimal and high-risk groups. CONCLUSIONS: Since 1995, the average height of children with T1DM has increased in parallel with increasing insulin doses. Clinicians should be aware of increased BMI in these patients and the associated risk of developing cardiovascular disease in the future.