Influence of obesity on bone density in postmenopausal women

OBJECTIVE: To evaluate the influence of obesity, age, and years since menopause on bone density. METHODS: A retrospective analysis of bone mineral density (BMD) obtained from 588 women, 41 to 60 years, previously menopaused (1-10 years before). RESULTS: Positive influence of obesity was confirmed by the significant differences in BMD at lumbar spine, femoral neck (FN), and trochanter (TR) between the groups (p < 0.01). Age and years since menopause (YSM) were negatively correlated with BMD at all sites (p = 0.000). Comparing patients within 1 to < 6 YSM versus 6 to 10 YSM, BMD was higher in the former at LS and FN (p < 0.005), despite the higher BMI in the older group (p = 0.01). Obese patients had a lower prevalence of osteoporosis at LS and FN (p = 0.009). Regression analysis identified BMI as the strongest determinant of FN and TR BMD, while YSM was the strongest determinant of LS BMD. CONCLUSION: The protective effect of obesity is overtaken by age and estradiol deficiency. We recommend that even obese postmenopausal women should be screened for osteoporosis.