Is the change in body mass index among children newly diagnosed with type 1 diabetes mellitus associated with obesity at transition from pediatric to adult care?

Background: Insulin therapy is lifesaving treatment for individuals with type 1 diabetes (T1D). Its initiation maybe associated with significant weight gain because of change from a catabolic to an anabolic state. Excessive weight-gain increases the risk of obesity and is associated with chronic disease.

Objective: To examine if change in body mass index (BMI) among children in the 6 months after diagnosis with type 1 diabetes mellitus is associated with long-term obesity.

Methods: This was a population-based retrospective study of 377 children (aged 2-18 yr) with type 1 diabetes. Measured heights and weights were used to calculate BMI z-scores based on Centers for Disease Control and Prevention (CDC) cut-points. Generalized Linear Models using BMI group, and age group at diagnosis; postdiagnosis weight change; and sex were applied to assess associations between postdiagnosis weight change and BMI z-score at transition to adult care.

Results: Mean BMI z-score increased from 0.28 at diagnosis, to 0.53 at 6 months and 0.66 at transition to adult care. Change in BMI z-scores differed by initial BMI group and magnitude of postdiagnosis weight change. Younger children (<11 yr) had higher (p = 0.004) BMI z-scores at diagnosis but not at last visit (p = 0.1) than older (≥11 yr) children at diagnosis. BMI z-score at diagnosis, postdiagnosis weight change, female sex, and longer duration with TID were associated with higher BMI z-score at time of transition.

Conclusions: BMI z-score at diagnosis was the strongest predictor of BMI z-score at time of transition to adult care, however; its effect was mediated by magnitude of weight change 6 months after diagnosis, sex, and age group at diagnosis.