[Bone mineral density of the lumbar spine and its relation to biological and lifestyle factors in middle-aged and aged Japanese women (Part 3). Relationships of physical fitness and lifestyle factors to bone mineral density in premenopausal and postmenopausal women].

We recruited community-dwelling women for participation in a study to investigate the effects of risk factors in lifestyle on bone mineral density (BMD). The subjects were 177 women aged 35 years and over living in a rural area in Fukui Prefecture. Their BMD of the lumbar spine (L2-L4) was determined by dual energy X-ray absorptiometry (DXA). In addition to measurements of height, body weight and grip strength, the lifestyles of the women, including physical load in work, sporting activities, smoking habits, calcium intake, and history of bone fracture were interviewed in detail. Adjusted for age, the BMD significantly correlated to body weight (r = 0.337, p < 0.05 for premenopausal women and r = 0.289, p < 0.01 for postmenopausal women) and body mass index (kg/m2) (r = 0.291, p < 0.05 for premenopausal women and r = 0.190, p < 0.05 for postmenopausal women). These results indicated the lower body weight to be a risk factor for the osteoporotic process in middle-aged and aged women. With respect to the grip strength as a physical fitness indicator, a significant correlation coefficient (r = 0.267, p < 0.01) with BMD was obtained for postmenopausal women independent of age and body weight. In univariate analysis, BMD showed no significant correlations with sporting activities, smoking habits, lower back pain and history of bone fracture for either premenopausal women or postmenopausal women.(ABSTRACT TRUNCATED AT 250 WORDS)