THE EFFECT OF BODY-COMPOSITION ON BONE-DENSITY IN PRE-MENOPAUSAL AND POSTMENOPAUSAL WOMEN

Objectives: To investigate the relative contribution of body compositi on (lean and fat) to bone mineral density (BMD), 196 premenopausal and 128 postmenopausal Japanese women were enrolled. Methods: Total fat m ass, total lean mass, lumbar BMD (L2-L4), and total body BMD were meas ured by dual-energy X-ray absorptiometry (DEXA, Hologic QDR 2000, MA, USA). Physical characteristics were also recorded for each subject. Co rrelation between BMD and variables were calculated for each of the tw o groups in single and stepwise regression analyses. Results: Total le an mass was significantly higher in premenopausal women than postmenop ausal women (P < 0.0001), while body weight, body mass index, and tota l fat mass were not different between the two groups. In stepwise regr ession analysis, total lean mass was the most powerful determinant of lumbar BMD and total body BMD in premenopausal women. In postmenopausa l women, total fat mass was the most significant determinant of lumbar BMD, while total lean mass was the most significant determinant of to tal body BMD. Conclusions: These findings suggest that there is a diff erence between pre- and postmenopausal women in the relative contribut ion of lean and fat mass. Total lean mass is the most significant dete rminant of BMD in premenopausal women. On the other hand, total fat ma ss may have some advantages in maintaining BMD in postmenopausal women . (C) 1997 Elsevier Science Ireland Ltd.