Relative contribution of lean and fat mass component to bone mineral density in males

We investigated the relative contribution of lean body mass (LBM) and body fat mass to bone mineral density (BMD) in 93 healthy Japanese male volunteers (mean age, 33.1 +/- 6.9 years; range, 18-54 years). Age, height (Ht), weight (Wt), and body mass index (BMI, Wt/Ht(2)) were recorded. Body fat mass, percentage of body fat, body fat mass/Ht(2), LBM, LBM/Wt, LBM/Ht(2), and lumbar spine (L2-L4) and total body BMD (TBBMD) were measured by dual-energy X-ray absorptiometry. On the Pearson correlation test, LBM was positively correlated with L2-L4 BMD. LBM, LBM/Wt, and LBM/Ht(2) were positively correlated with TBBMD. However, body fat mass and body fat mass/Ht(2) were not correlated with lumbar spine and total body BMD. On the partial correlation test, LBM was still correlated with lumbar spine ( r = 0.307, P < 0.05) and total body BMD ( r = 0.545, P< 0.0001), irrespective of age and height, whereas body fat mass was not correlated with BMD of these sites ( r = -0.069 and -0.169, respectively). We concluded that, in males, LBM is one of the significant determinants of BMD whereas body fat mass is a negligible BMD determinant.