健康青年人体成分对局部和全身骨密度的影响

摘要

目的探讨北京地区健康青年人脂肪组织质量（ fat mass， FM）和肌肉组织质量（ lean mass， LM）对局部和全身骨密度（ bone mineral density ， BMD）的影响。方法使用双能X线吸收法测定上肢、大腿、躯干和全身的骨密度、体脂率（ fat percentage ， Fat％）、脂肪组织质量和肌肉组织质量。根据体质量指数分为正常体质量组、超质量组和肥胖组。 Pearson相关分析和偏相关分析探索各部位BMD与全身和局部体脂率、脂肪组织质量和肌肉组织质量之间的关系。结果共纳入80名19.4～31.0岁的健康受试者。 Pearson相关分析显示男性上肢、大腿和全身BMD与全身体脂率（上肢r ＝0.185， P＝0.252；大腿 r ＝0.069， P＝0.674；全身r＝0.181， P＝0.263）和局部体脂率（上肢r＝0.141， P＝0.386；大腿r＝0.025， P＝0.876）及全身FM （上肢r＝0.294， P＝0.065；大腿r＝0.163， P＝0.316；全身r＝0.302， P＝0.059）和局部FM （上肢r＝0.290， P＝0.069；大腿r＝0.155， P＝0.340）均无显著相关关系，但女性各部位BMD与全身体脂率（上肢r ＝0.581， P＝0.000；大腿r ＝0.449， P ＝0.004；躯干r＝0.677， P＝0.000；全身 r ＝0.631， P＝0.000）、局部体脂率（上肢r＝0.477， P＝0.002；大腿r＝0.386， P＝0.014；躯干r＝0.689， P＝0.000）、全身FM （上肢r＝0.683， P＝0.000；大腿r＝0.615， P＝0.000；躯干r＝0.797， P＝0.000；全身r＝0.775， P＝0.000）和局部FM （上肢r＝0.669， P＝0.000；大腿r＝0.616， P＝0.000；躯干r＝0.778， P＝0.000）均呈显著正相关。但控制年龄、性别和体质量指数后，上肢、大腿和全身BMD仅与全身LM （上肢r＝0.266， P＝0.020；大腿r＝0.372， P＝0.001；躯干r＝0.312， P＝0.006；全身r＝0.371， P＝0.001）和局部LM （上肢r＝0.391， P＝0.000；大腿r＝0.443， P＝0.000）呈显著正相关。结论肌肉组织质量是影响青年人各部位BMD的主要因素。%Objective To investigate the impact of fat mass (FM) and lean mass (LM) on regional and total bone mineral density ( BMD ) in healthy young Chinese adults in Beijing .Methods BMD, body fat percentage (Fat%), FM and LM at the arms, legs, trunk and total body were measured by dual-energy X-ray absorptiometry.The participants were divided into three groups based on body mass index (BMI): normal weight, overweight and obesity. The correlations between whole body and regional BMD and total Fat %, FM and LM were investigated using Pearson cor-relation test and partial correlation analysis .Results The study involved 80 healthy adults aged 19.4 to 31.0 years. There was no significant correlation between BMD at arms , legs and total body and total Fat% ( arms: r=0.185 , P=0.252;legs:r=0.069 , P=0.674; total body: r=0.181 , P=0.263 ) and regional Fat% ( arms: r=0.141 , P=0.386;legs:r=0.025 , P=0.876 ) , as well as total FM ( arms: r=0.294 , P=0.065; legs: r=0.163 , P=0.316;total body:r=0.302 , P=0.059 ) and regional FM ( arms:r=0.290 , P=0.069;legs:r=0.155 , P=0.340 ) in men, but both total Fat%( arms: r=0.581 , P=0.000: legs: r=0.449 , P=0.004: trunk: r=0.677 , P=0.000: total body:r=0.631 , P=0.000 ) and regional Fat%( arms:r=0.477 , P=0.002:legs:r=0.386 , P=0.014:trunk:r=0.689 , P=0.000 ) , as well as total FM ( arms:r=0.683 , P=0.000:legs:r=0.615 , P<0.001:trunk:r=0.797 , P=0.000:total body:r=0.775 , P=0.000 ) and regional FM ( arms: r=0.669 , P=0.000: legs: r=0.616 , P=0.000:trunk:r=0.778, P=0.000) showed statistically positively correlations with BMD at all sites .However, after adjusting for age , gender and BMI , only total LM ( arms: r=0.266 , P=0.020: legs: r=0.372 , P=0.001: trunk:r=0.312 , P=0.006:total body: r=0.371 , P=0.001 ) and regional LM ( arms: r=0.391 , P=0.000: legs: r=0.443 , P=0.000 ) continued to be positively associated with BMD at arms , legs and total body .Conclusion It was suggested that LM was the strongest predictor of BMD at different sites in this group of healthy young adults .