ABSTRACT
OBJECTIVE: To track bone mineral acquisition in adolescents with type 1 diabetes (DM). STUDY DESIGN: Subjects were adolescents, ages 12 to 18 years, with DM (n=42) and a healthy regional reference (n=199). Measurements of tibia bone characteristics by peripheral quantitative computed tomography (pQCT) and spine and whole body (WB) by dual-energy x-ray absorptiometry (DEXA), anthropometrics, and lifestyle questionnaires were obtained during a 12-month period. Disease duration, insulin dose, renal function, and glycosylated hemoglobin (HbA1c) values for the previous 12 months were recorded. RESULTS: Body size and maturation were similar between groups. DM had lower tibia, spine, and WB bone characteristics but greater muscle mass (LBM) and lower bone mineral content (BMC)/LBM at baseline and 12 months. Annual gains for tibia cortical bone and WB BMC/LBM were lower and inversely related to HbA1c levels (R=-0.36 to -0.51), whereas spine area and density and WBLBM were greater and were predicted by pubertal-driven growth. Overall, the DM cohort had 8.5% less WB BMC/LBM, suggesting that bone mineral deposition was not adequately adapted to muscle gains. CONCLUSIONS: Adolescents with type 1 diabetes continue to have smaller bone mass and bone size despite normal growth and maturation. Poor metabolic control appears to negatively influence bone mineral acquisition.
