Bone Size Normalizes with Age in Children and Adolescents with Type 1 Diabetes Mellitus

Objective: To establish whether type 1 diabetes mellitus (T1DM) has a long-term effect on bone development in children and adolescents. Methods: Bone characteristics and muscle cross-sectional area (CSA) were analyzed crosssectionally at study start in 41 (19f/22m) patients and reevaluated after 5.56 ± 0.4 years using peripheral quantitative computed tomography (pQCT). We hypothesize that bone size and muscle mass normalize with age. Results: At first evaluation mean age was 9.87±2.3 years and mean disease duration 4.31± 2.9 years. Height was -0.36 ± 1.9 SD and body mass index (BMI) was 0.39 ± 0.9 SD. Parameters of bone size were low in the whole patient group (corrected for patient’s height). At reevaluation, mean age was 15.44 ± 2.3 years and patients had a mean height of -0.12 ± 0.8 SD. BMI-SD had increased to 0.57 ± 1.1. Total and cortical CSA had normalized. Those patients with an increase in total CSA had a significant younger age at disease manifestation and a younger age at initial pQCT measurement. Bone size was well adapted to muscle mass expressed as the ratio of bone mineral content (BMC) per muscle mass and a close correlation was shown between rise in bone size and in muscle CSA (r=0.46, p=0.03). Conclusion: Patients with manifestation of T1DM at an early age had transient impaired bone development. Within the follow-up period, the greatest increase in bone size was found in these patients. In adolescence, all patients had a normal bone size and an appropriate adaptation of bone on muscle.