BONE-DENSITY AND LIFE-STYLE CHARACTERISTICS IN PREMENOPAUSAL AND POSTMENOPAUSAL CHINESE WOMEN

The relationships between bone health and various lifestyle factors we re examined in a cross-sectional study in 775 Chinese women aged 35-75 years. Bone mass was significantly positively associated with body we ight, height, body mass index (BMI) and duration of breastfeeding, but was not significantly associated with other lifestyle variables, incl uding alcohol consumption, parity, age at menarche and age at menopaus e after adjusting for age and body weight. A positive association was observed in premenopausal women (but not in postmenopausal women) for bone density with current cigarette smoking and plasma and urinary cot inine (the major metabolite of smoking). However, the confounding effe cts of other unknown factors present in this cross-sectional study may not be excluded. Daily physical activity, as indicated by time spent working in the fields, was found consistently to be positively associa ted with bone mass (p < 0.0001). When these women were grouped into th ree physical activity levels on the basis of occupation and daily work intensity, those undertaking heavy labor also had significantly highe r radial bone mass than women undertaking light or medium labor. These results suggest a protective effect of daily physical activity on bon e health in both pre- and postmenopausal women.