Relative Contributions of Aging and Menopause to Bone Loss in Chinese Women

The forearm bone mineral content （BMC） were determined by single photon absorptiometry （SPA） in 490 cases of healthy Chinese Han women, aged 30-78, 78 premenopausal and 412 postmenopausal with menopausal years covering from 0.5 to 30. BMC decreased significantly after age 45 or the occurence of menopause （P＜0.05）,but the different age groups showed no significant difference before age 55 in the 78 premenopausal women （P＞0.05）. No sooner occured the menopause than bone loss accelerated, and 2.4～10.5% of BMC was lost a year within 3 year which followed by 2～3% annually while the rate in (he period of 10～15 years postmenopausal became less than 1%. The surgical menopause group had the same BMC as the natural menopause group （P＞0.05）. The incidence of postmenopausal osteoporosis was about 40% among the 412 postmenopausal women. Considering the varied age of menopause and the accelerating bone loss in the early postmeno pausal periods, we suggest that menopause play more important role than aging in the prediction of women ’s bone loss.