定量CT研究成年女性腰部椎后肌群体质成分与腰椎骨密度的相关性

Study of the relationship between posterior vertebral muscle composition and bone mineral density of the lumbar vertebra in adult women with quantitative computed tomography

目的探讨成年女性腰部椎后肌群体质成分与腰椎骨密度的相关关系。方法将518名21~81岁的成年女性按年龄分为青中年组(≤50岁)和老年组(>50岁),使用定量CT(QCT)测量L2~L4椎体骨密度(BMD)及L3椎体中部层面椎后肌群的脂肪面积、肌肉面积、脂肪肌肉比。使用独立样本T检验比较两组间差异,使用偏相关及多元线性回归分析研究BMD与年龄、BMI及椎后肌群体质成分的相关关系。结果青中年组BMI、椎后肌群脂肪面积及脂肪肌肉比低于老年组,而BMD及椎后肌群肌肉面积高于老年组,差异有统计学意义(P<0.01)。控制年龄、BMI因素偏相关分析结果显示,青中年组及老年组BMD与椎后肌群脂肪面积呈负相关(r=-0.178、-0.200,P<0.05),与脂肪肌肉比呈负相关(r=-0.138、-0.177,P<0.05),而与肌肉面积无显著相关性(r=-0.050、0.066,P>0.05)。回归分析显示,椎后肌群脂肪面积、年龄、BMI是BMD的主要影响因素。结论成年女性腰部椎后肌群脂肪浸润程度与腰椎骨密度存在相关性,且相关性随年龄而增加。

Objective To investigate the relationship between posterior vertebral muscle volume and fat content and bone mineral density（BMD） of the lumbar vertebra in adult women. Methods A total of 518 females aged from 21 to 81 years were selected from the patients who underwent quantitative computed tomography（QCT） scan of the lumbar spine. They were divided into young and middle-aged group（≤50 years）,elderly group（ 50 years）. QCT were performed to obtain the muscle fat area,skeletal muscular area,and fat muscle ratio of the posterior vertebral muscles at L3 level. Statistical analysis was performed using independent-samples T test,partial correlation analysis,and multiple regression analysis. Results BMI,muscle fat area,and fat muscle ratio in young and middle-aged group was lower than those in elderly group. BMD and skeletal muscular area in young and middle-aged group was higher than those in elderly group（P〈0. 01）. The lumbar BMD was negatively correlated with muscle fat area and fat muscle ratio in both young and middle-aged group（r =-0. 178,-0. 138,P〈0. 05） and elderly group（r =-0. 200,-0. 177,P〈0. 05）,but had no significant correlation with skeletal muscular area in both groups（r =-0. 050,0. 066,P〉0. 05）. Regression equation showed that muscle fat area,age,and BMI were main influential factors of BMD. Conclusion Muscle fat infiltration of the posterior vertebral muscles is correlated with lumbar BMD,and the correlation increases with aging.