POSTMENOPAUSAL BONE-MINERAL DENSITY - RELATIONSHIP TO CALCIUM INTAKE,CALCIUM-ABSORPTION, RESIDUAL ESTROGEN, BODY-COMPOSITION, AND PHYSICAL-ACTIVITY

Physical and lifestyle data were collected from 62 postmenopausal wome n who had declined hormone replacement therapy. Potential predictor va riables were examined for their associations with bone mineral density (BMD) of the lumbar spine and femoral neck as assessed by dual x-ray absorptiometry. Body weight demonstrated the strongest association wit h lumbar BMD; lean body mass demonstrated the strongest association wi th femoral BMD. Together with the natural logarithm of the number of y ears since menopause (In YSM) these anthropometric variables explained 36 and 34% of the variability of femoral and lumbar BMD, respectively . Serum estradiol levels demonstrated a weak positive association with BMD, which lost statistical significance after adjustment for body ma ss. Similarly, cardiovascular fitness was positively associated with f emoral BMD prior to but not following adjustment for body mass. Contro lling for years since menopause and body mass, the product of dietary calcium and calcium absorption demonstrated a weak positive correlatio n with femoral BMD (partial r = 0.30). The intake of tea was positivel y and significantly associated with both bone density measurements. In multiple regression analysis, femoral BMD was best explained by the l ean body mass, In YSM, and the daily intake of tea (r(2) = 0.50). Simi larly, lumbar BMD was best explained by body weight, In YSM, and intak e of tea (r(2) = 0.44). Body mass is a major predictor of postmenopaus al bone density at the hip and spine. ii positive association between dietary calcium and BMD was detected only by taking into account the i ntestinal absorptive efficiency.