Body fat distribution is associated with lumbar spine bone density independently of body weight in postmenopausal women

Abstract Objective To assess the association between the body fat distribution and axial bone mineral density (BMD) in postmenopausal women with or without hormone replacement therapy (HRT). Design Cross-sectional population-based study. Setting University of Eastern Finland, Bone and Cartilage Research Unit, Kuopio, Finland. Population 198 postmenopausal women, mean age 67.5 (1.9 SD), mean BMI 27.1 (3.9 SD). Methods Regional body composition and BMD assessed by dual X-ray absorptiometry (DXA, Prodigy). Main outcome measures Spinal and Femoral BMD. Results Out of the body composition parameters, FM was the main determinant of postmenopausal bone mass. Only the lumbar spine (L2–L4) BMD, not the femoral neck BMD, was positively associated with the trunk FM. Positive trends for association were revealed between the spinal BMD and the trunk FM regardless of the use of HRT. Adjustments did not change the results. Conclusions Higher trunk fat mass was associated with the spinal BMD, but not with the hip BMD in postmenopausal women, irrespective of the HRT use. In addition to biological factors, uncertainties related to DXA measurements in patients with varying body mass may contribute to this phenomenon.