FAT OR LEAN TISSUE MASS - WHICH ONE IS THE MAJOR DETERMINANT OF BONE-MINERAL MASS IN HEALTHY POSTMENOPAUSAL WOMEN

The relative importance of fat and lean tissue mass in determining bon e mineral mass among postmenopausal women was examined in this 1-year. longitudinal study, Fifty postmenopausal Caucasian women entered the study; 45 of them completed a 1-year follow up. Dual-energy Ii-ray abs orptiometry was employed for measuring total and regional bone mineral density (BMD) and bone mineral content (BMC), fat tissue mass (FTM), lean tissue mass (LTM), and body weight. Results from linear regressio n analysis using the cross-sectional data (n = 50) of the study indica ted that LTM explained a larger percentage of variation in bone minera l mass than did FTM. FTM and LTM were found to be moderately correlate d (r = 0.55); when FTM was entered in the same predicting regression m odels, LTM was a significant predictor (p < 0.05) of the total and reg ional BMC, but not BMD, The percent FIM (and inversely %LTM) was corre lated with BMD and BMC, but significant correlation was primarily foun d only for total body BMD (or BMC), Weight was the best predictor of t otal body BMD and BMC, Longitudinally (n = 45), annual changes in both FTM and weight were significantly associated with annual changes in r egional BMD after adjustment for initial bone mineral values (p < 0.05 ), We conclude that bone mineral mass is more closely related to LTM t han to FTM, while annual changes in regional BMB) are more closely cor related with changes in FTM in healthy postmenopausal women. Meanwhile , increased body weight is significantly associated with increased bon e mineral mass.