Bone Abstracts

Objectives: To evaluate progression of BMD and bone mineral content (BMC) during pubertal development and Influence of body composition and vitamin D on BMD and BMC in children and adolescents.

Material and method: This cross sectional study was part of an ongoing health survey of Delhi school children which recruited 1905 apparently healthy school children (835 boys; 1070 girls) in the age group of 6–17 years. After brief history, anthropometry and pubertal assessment, blood samples were collected for measurement of serum 25-hydroxy vitamin D (S.25Vit-D) and intact parathyroid hormone (iPTH). Whole body DXA scans were performed using GE Lunar Prodigy scanner. Areal BMD was computed. fat mass index (FMI) was calculated by total fat mass in Kg/square of height in meters.

Results: The mean age of subjects was 13.27±2.48 years and mean FMI was 5.59±3.1 kg/m² (boys – 4.65±3.1; girls – 6.5±2.81). Vitamin D deficiency (S.25 Vit-D <20 ng/ml) was present in 96.8% subjects. BMD and BMC increased progressively with progression of puberty in both boys and girls but maximum gain was observed from pubertal stage 2–4. In pre-pubertal children, boys had significantly higher Total BMC and BMD/BMC at spine than girls but Femur Neck (FNBMD/BMC) was not different. Boys showed higher percentage rise in BMD from stage 1–5 in comparison to girls. FMI showed significant positive correlation with TBMC; r=0.40, P=<0.001, lumber spine BMD (LSBMD); r=0.11, P=<0.001 and with FNBMD; r=0.13, P=<0.001; but did not show any significant correlation with S.25Vit-D or iPTH. Similarly, total lean mass also showed significant positive correlation with TBMC, LSBMD and FNBMD in all subjects as well in all pubertal groups. S.25 Vit-D was also positively correlated with TBMC (r=0.13, P=<0.001), LSBMD (r=0.15, P=<0.001) and FNBMD (r=0.06, P=0.006).

Conclusion: BMD progressively increases during pubertal development with maximum gain occurring between pubertal stages 2 and 4. FMI is positively correlated with BMD/BMC all three sites.

Funding: This work was supported by the DRDO, New Delhi, India (research grant INM-305, INMAS)

Disclosure: The authors declared no competing interests.