Relative importance of lean mass and fat mass on bone mineral density in a group of Lebanese elderly men

The aim of this study was to determine the relative importance of lean mass and fat mass on bone mineral density [BMD] in a group of Lebanese elderly men. Seventy Lebanese men [aged 65-84 years] participated in this study. Body weight and height were measured and body mass index [BMI] was calculated. Body composition [lean mass, fat mass and fat mass percentage] was assessed by dual-energy X-ray absorptiometry [DXA]. Bone mineral content [BMC] of whole body [WB] and BMD of WB, total hip [TH], femoral neck [FN], ultra distal [UD] radius and 1/3 radius were measured by DXA. The ratios WB BMC/height and WB BMD/height were calculated. Fat mass and lean mass were found to be positively correlated to WB BMC, WB BMC/height, and to WB, TH, FN, UD radius and 1/3 radius BMD. After controlling for age and height, fat mass was more strongly correlated to TH BMD and FN BMD than lean mass while lean mass was more strongly correlated to WB BMC, WB BMD, UD radius BMD and 1/3 radius BMD than fat mass. This study suggests that, in elderly men, fat mass is a stronger determinant of TH and FN BMD than lean mass while lean mass is a stronger determinant of WB BMC, WB BMD, UD radius BMD and 1/3 radius BMD than fat mass