Relationship between body mass index and BMD in 557 postmenopausal women

Objective To study the relationship between body mass index (BMI) and bone mineral density (BMD) in postmenopausal women at different ages. Methods Bone mineral density in the lumbar spines (L2-4 ) and the proximal femur (femoral neck, Ward's triangle, and trochanter major) of 557 postmenopausal women aged between 50-78 years were measured by dual energy X-ray absorptiometry (DEXA), and their BMI were calculated. Based on BMI, the women were divided into 3 groups (BMI≤ 20 kg/m2 , 25 ≥ BID 20 kg/m2 , and BMI 25 kg/m2), and they were also divided into 3 age groups (50-59,60-69, and 70-78 years). The relationship between BMI and BMD was studied separately in different age groups. Results BMD increased significantly with increasing BMI ; there were significant differences in BMD between different BMI groups in all age groups. Conclusions (1) BMI is significantly correlated with BMD in postmenopausal women; attention shoud be paid to the postmenopausal women who have lower weight, or high risk of fracture. (2) As for those overweight or obese postmenopausal women, it isn't sensible to increase BMD by means of gaining weight because it may increase other risks, such as hypertension , diabetes mellitus, coronary heart disease, myocardial infarction, and stroke, (3 ) It is important to increase the peak bone mineral density in women of childbearing age by other means, such as taking more physical exercise, drinking more milk and not reducing weight blindly.