Weight gain trajectories and obesity rates in intensive and conventional treatments of type 1 diabetes from the DCCT compared with a control population without diabetes

Aim Obesity is a significant health issue for participants with type 1 diabetes undergoing intensive diabetes management. The temporal pattern and factors associated with weight gain after treatment initiation remain poorly understood including how weight gain in participants with and without type I diabetes compare. Our aim was to compare weight gain in those receiving intensive (INT) and conventional (CONV) type 1 diabetes treatment to a population without diabetes. Methods Participants included men and women of 18 years and older in the Diabetes Control and Complications Trial (DCCT) randomized to INT (n = 562) or CONV (n = 568) and a prospective, observational cohort without diabetes from the Coronary Artery Development in Young Adults (CARDIA, controls) study (n = 2446). Body mass index (BMI) trajectories and obesity prevalence were compared between groups and candidate metabolic and therapeutic moderators investigated. Results Annual weight gain with INT peaked 1.3 years after initiation and was greater than both CONV and controls before and after this peak. Obesity prevalence with INT was lower than controls at baseline, was similar to controls at 2 years and surpassed controls by 5 years. Obesity rates with CONV remained below controls at all time points. Greater annual weight gain in the DCCT was associated with lower haemoglobin A(1c), higher insulin dose and family history of type 2 diabetes. Conclusions Greater weight gain accompanying INT therapy occurs in two stages, leads to similar or greater obesity rates than controls after 2 years and is primarily modified by glucose control and family history, supportive of a therapeutic-genetic influence on weight trajectories.