天津市老年女性肌少症评价方法比较

Comparison of evaluation methods of sarcopenia in elderly women in Tianjin

目的通过对老年女性肌少症不同评价方法的比较研究,找出较适用于天津市老年女性肌少症的评价方法。方法选取天津市老年(60~89岁)女性536例作为研究对象(研究组),并选取605例健康青年(20~29岁)女性作为参照组。采用身体成分分析仪测量其身体成分,主要指标包括体质量指数(body mass index,BMI)、体脂百分比(body fat percentage,BF%)、骨骼肌质量(skeletal muscle mass,SMM)、去脂体重(lean body mass,LBM)、四肢骨骼肌质量(appendicular skeletal muscle,ASM)等。根据相对四肢骨骼肌质量指数(relative appendicular skeletal muscle,RASM)或骨骼肌质量指数(skeletal muscle mass index,SMI),分别参照以下标准界定女性肌少症:国际肌少症工作组(International Working Group on Sarcopenia,IWGS)标准:RASM<5.67 kg/m2;欧洲老年肌少症工作组(European Working Group on Sarcopenia in Older People,EWGSOP)标准:RASM<4.23 kg/m2;亚洲肌少症工作组(Asian Working Group for Sarcopenia,AWGS)标准:RASM<5.7 kg/m2。在上述机构的分级思路基础上提出RASM分级标准:3.13<RASM<4.95 kg/m2为RASM I级,RASM<3.13 kg/m2为RASMⅡ级;以及SMI分级标准:22.28<SMI<32.53为SMIⅠ级,SMI<22.28为SMIⅡ级。采用ANOVA分析研究组肌肉质量随年龄变化的趋势;采用独立样本t检验分析受试者各项指标的差异性;Fisher确切概率法用于分析不同评价方法下肌少症检出率及其增龄趋势的差异性;选用受试者工作特性曲线(receiver operating characteristic curve,ROC)评价SMI评价方法与国际上各个老年肌少症工作组评价方法的敏感度和特异性。结果5种评价方法发现本研究老年女性肌少症检出率为0%~20%。其中,SMIⅠ级评价方法肌少症检出率最高(19.4%),而RASMⅡ级与EWGSOP评价方法无肌少症患者。SMIⅠ级评价方法显示,老年女性肌少症检出率在60~89岁整个年龄段呈现逐渐上升的趋势(Fisher确切概率法:P<0.01),分别为60~64岁14.74%,65~69岁17.14%,70~74岁27.4%,75~79岁30.43%,80~84岁34.78%,85~89岁50%。采用ROC曲线评价SMI与其他评价方法的敏感度和特异性,结果发现SMI与IWGS的曲线下面积(area under curve,AUC)0.682,P<0.01;与AWGS的AUC为0.557,P>0.05;与RASM的AUC为0.725,P>0.05。结论SMI评价方法较适合用于诊断天津市老年女性的肌少症,有利于较早、较准确发现肌少症。

Objective To find an applicable method to diagnose sarcoperia of elderly women in Tianjin through the comparison of different evaluation methods of sarcopenia.Methods A total of 536 elderly(60~89 years old)women in Tianjin were selected as study group,and 605 healthy young(20-29 years old)women were selected as the control group.Body composition was measured using a body composition analyzer.The main indicators included body mass index(BMI),body fat percentage(BF%),skeletal muscle mass(SMM),lean body mass(LBM),appendicular skeletal muscle(ASM),etc.According to relative appendicular skeletal muscle(RASM)or skeletal muscle mass index(SMI),the following criteria were used to define female sarcopenia:International Working Group on Sarcopenia(IWGS):RASM<5.67 kg/m2;European Working Group on Sarcopenia in Older People(EWGSOP):RASM<4.23 kg/m2;Asian Working Group for Sarcopenia(AWGS):RASM<5.7 kg/m2.According to the classification criteria of above organizations,we made RASM grading standard:RASM levelⅠfor 3.13<RASM<4.95 kg/m2,RASM levelⅡfor RASM<3.13 kg/m2;and SMI grading standard:SMI levelⅠfor 22.28<SMI<32.53,SMI levelⅡfor SMI<22.28.ANOVA was used to analyze the trend of muscle mass with age in the study group.The independent sample t test was used to analyze the differences of each indicator of the subjects.Fisher's exact probability method was used to analyze the difference of incidence rate and aging trend of sarcopenia under different evaluation methods.Receiver operating characteristic curve(ROC curve)was used to evaluate the sensitivity and specificity of the SMI evaluation method to sarcopenia in the elderly.Results Five evaluation methods showed that the detection rate of sarcopenia was 0%-20%.Among them,the ratio of sarcopenia was the highest in SMI levelⅠ(19.4%),while no sarcopenia was found in RASM levelⅡand EWGSOP.According to the SMI levelⅠevaluation method,the ratio of sarcopenia in the elderly women increased gradually in the whole age group of 60-89 years old(Fisher exact probability method:P<0.01),and they were 14.74%of aged 60-64,17.14%of aged 65-69,27.4%of aged 70-74,30.43%of aged 75-79,34.78%of aged 80-84,and 50%of aged 85-89,respectively.ROC curve was used to evaluate the sensitivity and specificity of SMI and other evaluation methods:area under AUC curve of IWGS was 0.682,P<0.01;area under AUC curve of AWGS was 0.557,P>0.05;area under AUC curve of RASM was 0.725,P>0.05.Conclusion SMI evaluation method is more suitable for the diagnosis of sarcopenia in elderly women in Tianjin,which is conducive to early and accurate detection of sarcopenia.