Association Between Physical Activity and Bone Mineral Density in Postmenopausal Women

This study examined associations between physical activity and bone mineral density (BMD) at the total femur, femoral neck, and lumbar spine among postmenopausal women using data from the 2024 Korea National Health and Nutrition Examination Survey (KNHANES IX-3).This cross-sectional secondary analysis included 880 naturally or surgically postmenopausal women, representing a weighted population of 5,099,536.Complex sample general linear models were applied using three models: an unadjusted model, an age-adjusted model, and a fully adjusted model controlling for age, body mass index, and age at menopause.In the fully adjusted model, walking days per week were positively associated with total femur and femoral neck BMD, whereas daily sedentary time was negatively associated with total femur BMD (p < .05).Aerobic physical activity was significantly associated with total femur BMD (B=0.017,p= .027),but not with femoral neck BMD.Musclestrengthening exercise showed no significant association with BMD at any skeletal site, and lumbar spine BMD was not significantly associated with any physical activity variable.These findings suggest that the relationship between physical activity and BMD differs according to activity type and skeletal site.Promoting regular weight-bearing activities such as walking while reducing prolonged sedentary behavior may help maintain bone health in postmenopausal women.