[Relationship between body composition and bone mineral density in healthy premenopausal women].

Objective: To investigate the relative contribution of fat mass and lean mass on bone mineral density (BMD) in premenopausal healthy women.

Methods: The BMD at lumbar spine, proximal femur and total body, together with fat mass and lean mass was determined by dual-energy X-ray absorptiometry (DEXA), the body height, weight, waist, and hip circumference were also measured, and body mass index (BMI) and waist-hip ratio were calculated in 282 premenopausal women.

Results: Fat mass was a major determinant for BMI, BMI and lean mass were positively related with L2-4, proximal femur and total body BMD (P = 0.000 for all), and lean mass were the only independent factor contributing to L2-4 (standardized coefficient beta = 0.282, P = 0.000), proximal femur (beta = 0.336, P = 0.000) and total body BMD (beta = 0.361, P = 0.000) in stepwise regression analysis. The relationship between BMI and BMD was further improved after controlling fat mass, while decreased or even lost when controlling lean mass.

Conclusions: Lean mass was an important factor determining BMD in premenopausal women.