EFFECT OF MENOPAUSE ON FEMORAL AND VERTEBRAL BONE LOSS

The aim of this study aas to investigate the effect of menopause on bo ne loss in the proximal femur and the lumbar spine. The rates of chang e in bone mineral density (BMD) were measured longitudinally by dual X -ray absorptiometry (DXA) at the femoral neck (FN), Ward's triangle (W T), and trochanter (TR) together with the lumbar spine in 81 healthy p ostmenopausal women (45-65 years of age) who had passed a natural meno pause, 6 months to 12 years before, A significant correlation between the rate of change and interval since menopause was evidenced. The bes t fit of the data was a binomial function of interval since menopause at the spine, FN, and WT and a simple linear regression at TR level, A t each skeletal site, the rate of bone loss (mean +/- SD) was signific antly different (p < 0.05) and twice as high in women who were between 6 months and 2 years postmenopausal at enrollment (FN, -1.82 +/- 1.1% ; WT, -2.43 +/- 1.7%; TR, -1.12 +/- 1.7%) than in those who were beyon d 5 years of menopause (FN, -0.48 +/- 0.8%; WT, -0.68 +/- 2.1%; TR, 0. 41 +/- 1.2%). A poor correlation (r = 0.39 - 0.42, p < 0.001),vas foun d between the rate of vertebral and that of femoral postmenopausal bon e loss, This study demonstrates that menopause is associated with a ra pid and transient bone loss in BMD of the proximal femur, which declin es with time after 3 years, These data suggest that therapy should be initiated as early as possible after menopause to prevent bone toss.