An epidemiologic study of osteoporosis in Taiwan

In 1989, a cross-sectional study was carried out in Taiwan to understand the distribution of bone mineral density (BMD) in the lumbar spine of Chinese people and to identify the risk factors associated with osteoporosis. BMD of the lumbar spine was measured by dual-photon absorptiometry in 404 healthy volunteers (266 women and 138 men, aged 15 to 83 years) living in Lin-Kou Township. The age-specific mean values of lumbar spine BMD were higher for men than for women after age 60. Furthermore, the BMD of women declined significantly after age 40. However, the BMD of men did not show a downward trend with age. In a multiple logistic regression analysis of fracture risk expressed as a categorical level of BMD, age, diabetes, and years since menopause were associated with lower BMD, while body mass index was associated with higher BMD. In a multiple linear regression analysis of BMD, significant variables were years since menopause, age, body mass index, and seaweed diet. Variables that were significant in bivariate analysis, but not multiple variable analysis were education, milk consumption, breast-feeding, frequency of pregnancy, and age at first menstruation. However, cigarette habits, alcohol consumption, and physical activity were not associated with the BMD level in any of these analyses.