BMI Z-Score Trajectories in Youth with T1D—An International Comparison

Obesity in youth with type 1 diabetes (T1D) has emerged as a challenge in care. Data from the Australasian Diabetes Data Network (ADDN), Diabetes Prospective Follow-up (DPV) in Austria and Germany, and T1D Exchange (T1DX) registry in the U.S. were compared to assess international differences in BMI z-score trajectories in youth with T1D. Longitudinal data from 11,513 participants between ages 8-17 years with T1D duration ≥1 year. and ≥5 aggregated body mass index (BMI) values (ADDN: N=1073, 46% female, mean HbA1c 8.3%; DPV: N=8722, 46% female, mean HbA1c 7.8%; T1DX: N=1718, 45% female, mean HbA1c 8.6%) were analyzed. Participants diagnosed with celiac and/or thyroid disease were excluded. Latent class growth modeling by Nagin was used to identify subgroups following similar BMI z-score trajectories. Five distinct trajectories were identified in ADDN and T1DX participants, and six in DPV (Figure). In all registries most participants in ADDN and T1DX maintained weight status over time. However, obese (BMI z-score ≥2) participants from ADDN achieved weight loss over time, compared to obese participants in T1DX, whose BMI SD increased during the teen years. In DPV, there were trajectories indicating dramatic weight gain/loss during puberty. Further analysis by sex and minority status will help to understand the within-registry and between-registry variation and may help target clinical interventions to achieve healthy weight in youth with T1D.