Relationship between body composition and bone mineral density of the lumbar spine and proximal femur: influence of years since menopause.

OBJECTIVES

To investigate the relationship between the body composition and regional bone mineral density (BMD) in postmenopausal women according to years since menopause (YSM).

METHODS

A total of 167 postmenopausal women with a mean age of 62.91 ± 5.09 years participated in this cross-sectional study. The average YSM was 11.96 ± 6.28 years. We used the DXA Lunar Prodigy Primo(™) device to assess the body composition parameters [body fat mass (BFM) and lean body mass (LBM)] and the BMD of the lumbar spine, proximal femur and total body.

RESULTS

The LBM was a stronger predictor of the proximal femur BMD than BFM in 1-10 YSM category, whereas the BFM was a stronger predictor of the proximal femur BMD than LBM in 11-20 and 21-30 YSM categories. The BMD of the lumbar spine showed a similar trend. A significant relationship was found between BMD of L(1)-L(4) and LBM in 1-10 YSM category (r = 0.26; p < 0.05). BFM was significantly associated with BMD of L(1)-L(4) in 11-20 YSM category (r = 0.25; p < 0.05). Significant relationships were found between total femur BMD and LBM in 1-10 YSM (r = 0.27; p < 0.05) and 11-20 YSM category (r = 0.25; p < 0.05). BFM was significantly associated with total femur BMD only in 11-20 YSM category (r = 0.40; p < 0.05).

CONCLUSION

The relationships between BMD and body composition are dependent on YSM and vary between selected segments.