绝经前健康妇女的身体组成成分与骨密度的关系

目的 探讨fat mass 和lean mass对绝经前健康妇女骨密度的影响程度。方法 在绝经前的健康妇女中,用双能X线骨密度仪测定腰椎、股骨近端和全身骨密度以及fat mass和lean mass,并测量身高、体重、腰围、臀围,计算体重指数(body mass index,BMI)和腰臀比。结果 fat mass 是决定BMI的主要因素;BMI和lean mass与L2-4股骨近端和全身骨密度呈正相关(P值均=0．000);多元逐步回归分析显示,只有lean mass才是决定L2-4(标准偏回归系数β=0．282,P=0．000)、股骨近端(β=0．336,P=0．000)和全身骨密度(β=0．361,P=0．000)的独立影响因素;在控制年龄因素的基础上控制fat mass后,BMI与骨密度的相关性提高,而控制lean mass 后,BMI与骨密度的相关性减弱,甚至消失。结论 lean mass是决定绝经前健康妇女骨密度的重要因素。

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.