The association between fat and lean mass and bone mineral density: The HealthyTwin Study

Abstract

The potential beneficial effects of increased body weight on bone mineral density (BMD) conflict with the adverseeffects of obesity on various health outcomes, necessitating more specific evaluations of the associationbetween each body component and BMD. In the present study, we evaluated associations of lean mass (LM)and fat mass (FM) with BMD in a Korean sample consisting of a total of 1782 men and women whose mean(standard deviation) age was 43.2 (12.6) years. They were selected from the Healthy Twin Study, a nationwideKorean twin and family study. BMD, FM and LM were measured using dual-energy X-ray absorptiometry.Quantitative genetic analysis and linear mixed analysis were performed with respect to familialrelationships and a wide range of probable covariates. Linear mixed analysis revealed that BMD was positivelyassociated with both FM and LM at each region of BMD measurement (whole body, spine, arms, and legs)in men, premenopausal women, and postmenopausal women. However, the association with BMD wasstronger for LM than FM. Both LM and FM had positive genetic correlations with BMD at each region, althoughthe correlation with BMD tended to be stronger for LM than FM. Together, these findings suggestthat increased LM, rather than FM, is more beneficial for BMD in the Korean population and warrants furtherstudy of the common genetic determinants of BMD and body composition.ⓒ 2012 Elsevier Inc. All rights reserved