Bone and mineral density in obese children

Objectives: The objective of this study was to assess bone mineral density (BMD) and related bone parameters in obese children aged 5–12 years and compare them with age- and sex-matched normal-weight peers. Material and Methods: This case–control study was conducted at a tertiary care centre in Northern India. Sixty obese children (body mass index >27 kg/m 2 , Indian Academy of Paediatrics 2015 charts) and 26 age- and sex-matched normal-weight controls were enrolled. Children with syndromic obesity, chronic illness, or medications affecting bone metabolism were excluded. Anthropometry and pubertal staging were assessed using standard protocols. Whole-body dual-energy X-ray absorptiometry (Hologic Discovery A) was used to measure total body less head (TBLH) and regional BMD, bone mineral content (BMC) and bone mineral area (BMA). Lean mass, fat mass and fat percentage were also estimated. Data were analysed using the Statistical Package for the Social Sciences 23.0 with multivariable regression adjusting for age, sex, height and pubertal stage. Results: Obese children showed significantly higher TBLH, lumbar spine and pelvic BMD compared to normal-weight peers ( P < 0.05). Whole-body BMC and BMA were also higher in obese children, while lumbar spine and pelvic BMA were lower. After adjusting for confounders, differences in total BMD and BMC remained statistically significant. TBLH-BMD and BMC positively correlated with height, weight and waist circumference. Lean mass had a more substantial positive influence on bone parameters than fat mass. Each kilogram increase in lean mass improved TBLH-BMD by 0.003 g/cm 2 , while each kilogram of fat mass decreased TBLH-BMD by 0.004 g/cm 2 but increased BMC and BMA modestly. Conclusion: Obesity in prepubertal Indian children is associated with mild but significant increases in bone mineral parameters, primarily mediated by lean mass rather than fat mass. Excessive adiposity without proportional lean mass gain may not confer additional skeletal benefits and may adversely affect bone quality. Early attention to balanced nutrition, muscle strengthening and weight management is essential to optimize bone health during growth.