The effects of weight status on treatment outcomes in a randomized clinical trial of multisystemic therapy for adolescents with type 1 diabetes and chronically poor metabolic control

Objective: The purpose of the study was to determine if being overweight attenuated the effect of multisystemic therapy (MST), an intensive, home-based psychotherapy, on metabolic outcomes among adolescents with type I diabetes and chronically poor metabolic control. As overweight is a marker of insulin resistance, it was hypothesized that weight status would limit the impact of behavioral changes in traditional aspects of adherence to the type I diabetes regimen on metabolic control. Methods: A randomized controlled trial was conducted with 127 adolescents with type I diabetes and hemoglobin Alc (HbA1c) >= 8% for the past year. Participants were randomly assigned to MST plus standard care (SQ or SC alone. Data were collected at baseline and 7 months posttest (i.e., treatment termination). Overweight was defined as body mass index > 85%. Results: Forty-one percent of the sample was overweight. Intent-to-treat analysis showed that adolescents in the MST group had a significant increase in frequency of blood glucose testing (BGT) [F(1,113) = 15.43, p = 0.0001] and a trend to significant improvement in HbA1c [F(1,123) = 2.99, p = 0.086] irrespective of weight. However, HbA1c decreased 0.91% (p = 0.002) for normal weight adolescents in the MST group compared with 0.20% (p = 0.570) for overweight adolescents in the MST group. Discussion: Despite improvements in adherence to BGT, overweight adolescents receiving an intensive behavioral intervention did not have a significant improvement in metabolic control compared with their normal weight peers. Overweight, an accepted marker of insulin resistance and a major public health issue, warrants increased consideration in intervention trials to improve the metabolic control of adolescents with type I diabetes.