The relationship between obesity and bone mineral density in children and adolescents: analysis of the National Health and Nutrition Examination Survey.

Abstract

This study observed the relationship between fat mass and distribution, and areal bone mineral density (aBMD) in children and adolescents. A retrospective study was conducted on US children and adolescents aged 8-19years. Whole body (less head) aBMD was evaluated. Height (Ht) adjusted Z-scores for aBMD were calculated. After controlling for age, gender, race, and lean body mass index (LBMI) Z-score, there were significant negative associations between fat mass index (FMI) Z-score and aBMD Ht-Z-adjusted Z-score (β = - 0.272, P < 0.001, R2 = 0.033). In the linear regression models with aBMD Ht-Z-adjusted Z-score as the dependent variable, the regression coefficients of android fat mass were - 0.241 (P < 0.05, R2 = 0.002), - 0.473 (P < 0.001, R2 = 0.036), and - 0.474 (P < 0.001, R2 = 0.038) for healthy weight, overweight, and obesity group, respectively. The regression coefficients of visceral adipose tissue (VAT) mass were - 0.218 (P > 0.05, R2 = 0.001), - 2.025 (P < 0.001, R2 = 0.044), and - 1.826 (P < 0.001, R2 = 0.039), and the regression coefficients of subcutaneous adipose tissue (SAT) mass were - 0.467 (P < 0.001, R2 = 0.004), - 0.339 (P < 0.01, R2 = 0.024), and - 0.347 (P < 0.001, R2 = 0.018) for healthy weight, overweight, and obesity group, respectively. The present study suggests that fat mass has a slightly negative association with bone development in children and adolescents. Trunk fat accumulation, especially visceral adipose tissue, was correlated with the lower level of aBMD. This association was obvious in overweight and obese children.