Determinants of bone mineral density in older postmenopausal Chinese women

Objective The study was performed to identify the risk factors of osteoporosis in older Chinese women. Methods Two thousand Chinese women aged above 65 years (65-98 years) were recruited. The subjects were interviewed by a structured questionnaire and had a physical examination. Bone mineral density (BMD) at the total hip and lumbar spine was measured by dual X-ray densitometry. Results On stepwise multiple regression, body weight, daily dietary calcium intake, history of diabetes mellitus and hypertension, and age of menopause were positively associated with BMD at total hip and spine. Age of menarche, duration of lactation and history of fracture at or after 50 years of age were significant negative predictors of BMD of total hip and spine. Age, current smoking, and history of gastrectomy were associated with lower BMD at the hip. Physical activity was associated with higher hip BMD. Tertiary education and alcohol consumption were associated with higher BMD at the spine. The explained variances of total hip BMD and spine BMD by these factors were 37.9% and 29.4%, respectively. Conclusion Lifestyle factors and medical history have significant influence on BMD in older postmenopausal Chinese women. The influence of gynecological and obstetric history was relatively small.