成年体检人群定量CT所测体脂肪分布与体重指数的相关性

Correlation between body fat distribution measured by quantitative CT and body mass index in adults receiving physical examination

目的分析成年体检人群定量CT(QCT)所测体脂肪分布与体重指数的相关性。方法本研究为横断面研究,选取2021年1—12月在河南省人民医院健康管理学科行胸部CT联合QCT检查的所有符合纳排标准的3205例成年体检人群为研究对象,收集其一般资料,采用QCT测量其皮下脂肪面积、内脏脂肪面积、腹部总脂肪面积、肝脏脂肪含量、腹型肥胖及脂肪肝检出率。根据体重指数18.5~<24.0 kg/m^(2)、24.0~<28.0 kg/m^(2)和≥28.0 kg/m^(2)将研究对象分为正常组(1343例)、超重组(1427例)和肥胖组(435例),采用单因素方差分析、χ^(2)检验比较3组QCT所测指标差异,采用Pearson及Spearman相关分析评估QCT所测指标与体重指数的相关性,采用受试者工作特征(ROC)曲线分析QCT对肥胖及脂肪肝的诊断效果。结果肥胖组皮下脂肪面积、内脏脂肪面积、腹部总脂肪面积、肝脏脂肪含量、腹型肥胖及脂肪肝检出率均显著高于超重组和正常组[男性,(147.60±46.44)比(104.33±27.68)、(73.46±22.65)cm^(2),(297.46±54.70)比(229.40±53.12)、(159.57±49.68)cm^(2),(445.06±70.24)比(333.73±62.91)、(233.02±61.87)cm^(2),11.30%(7.90%,15.55%)比8.75%(6.50%,11.70%)、6.60%(4.80%,8.70%),100.0%比96.0%、64.0%,92.9%比86.7%、73.3%;女性,(213.96±48.61)比(155.85±35.31)、(107.24±31.01)cm^(2),(185.41±43.88)比(142.48±41.75)、(96.56±36.50)cm^(2),(399.37±68.07)比(298.33±56.86)、(203.80±57.53)cm^(2),9.80%(6.90%,13.30%)%比7.30%(5.05%,9.80%)、5.40%(3.50%,7.20%),96.4%比74.8%、28.9%,87.3%比75.6%、56.5%],且均与体重指数呈正相关(男性,r/rs=0.709、0.738、0.831、0.402、0.464、0.225;女性,r/rs=0.798、0.695、0.841、0.416、0.605、0.276)(均P<0.001)。男性体检者基于QCT诊断所得肥胖检出率显著高于体重指数诊断所得(86.9%比16.6%),脂肪肝检出率显著高于超声诊断所得(83.6%比57.1%)(均P<0.001);女性体检者基于QCT诊断所得肥胖检出率显著高于体重指数诊断所得(49.3%比8.9%),脂肪肝检出率显著高于超声诊断所得(65.2%比27.6%)(均P<0.001)。ROC曲线显示,男性体检者以内脏脂肪面积142 cm^(2)为诊断肥胖的截点值时,其灵敏度、特异度分别为100%、15.8%;以肝脏脂肪含量5.0%为诊断脂肪肝的截点值时,其灵敏度、特异度分别为88.9%、25.1%;女性体检者以内脏脂肪面积115 cm^(2)为诊断肥胖的截点值时,其灵敏度、特异度分别为96.4%、55.3%,以肝脏脂肪含量5.0%为诊断脂肪肝的截点值时,其灵敏度、特异度分别为83.7%、43.2%。结论成年体检人群QCT所测腹部脂肪及肝脏脂肪等指标均与体重指数呈正相关,QCT诊断肥胖及脂肪肝的效果优于体重指数及超声。

Objective To analyze the correlation between body fat distribution measured by quantitative CT(QCT)and body mass index in adults receiving physical examination.Methods It was a cross-sectional study.From January to December 2021,3205 adults undergoing physical examination who met the inclusion criteria and underwent chest CT and QCT examination in the health management discipline of Henan Provincial People's Hospital were selected as the research objects.The general data were collected;and the subcutaneous fat area,visceral fat area,total abdominal fat area,liver fat content,abdominal obesity and fatty liver detection rate were measured by QCT.According to body mass index,the subjects were divided into normal group(18.5-<24.0 kg/m^(2),1343 cases),overweight group(24.0-<28.0 kg/m^(2),1427 cases)and obesity group(≥28.0 kg/m^(2),435 cases).One-way analysis of variance and χ^(2) test were used to compare the differences of QCT indexes among the three groups.Pearson and Spearman correlation analysis were used to evaluate the correlation between QCT indexes and body mass index.Receiver operating characteristic(ROC)curve was drawn to analyze the diagnostic effect of QCT on obesity and fatty liver.Results Subcutaneous fat area,visceral fat area,total abdominal fat area,liver fat content,abdominal obesity and fatty liver detection rate in obese group were all significantly higher than those in overweight group and normal group[males,(147.60±46.44)vs(104.33±27.68),(73.46±22.65)cm^(2);(297.46±54.70)vs(229.40±53.12),(159.57±49.68)cm^(2);(445.06±70.24)vs(333.73±62.91),(233.02±61.87)cm^(2);11.30%(7.90%,15.55%)vs 8.75%(6.50%,11.70%),6.60%(4.80%,8.70%);100.0%vs 96.0%,64.0%;92.9%vs 86.7%,73.3%;females,(213.96±48.61)vs(155.85±35.31),(107.24±31.01)cm^(2);(185.41±43.88)vs(142.48±41.75),(96.56±36.50)cm^(2);(399.37±68.07)vs(298.33±56.86),(203.80±57.53)cm^(2);9.80%(6.90%,13.30%)vs 7.30%(5.05%,9.80%),5.40%(3.50%,7.20%);96.4%vs 74.8%,28.9%;87.3%vs 75.6%,56.5%],and were all positively correlated with body mass index(males,r/rs=0.709,0.738,0.831,0.402,0.464,0.225;females,r/rs=0.798,0.695,0.841,0.416,0.605,0.276)(all P<0.001).In both male and female subjects,the detection rates of obesity based on QCT were significantly higher than those based on body mass index(male,86.9%vs 16.6%;female,49.3%vs 8.9%),and the detection rates of fatty liver based on QCT were significantly higher than those based on ultrasound(male,83.6%vs 57.1%;female,65.2%vs 27.6%)(all P<0.001).ROC curve showed that when the visceral fat area of 142 cm^(2) was used as the cut-off value for the diagnosis of obesity in male subjects,the sensitivity and specificity was 100%and 15.8%,respectively;and when the cut-off value of liver fat content 5.0% was used to diagnose fatty liver,the sensitivity and specificity was 88.9%and 25.1%,respectively.When the visceral fat area of 115 cm^(2) was set as the cut-off value for the diagnosis of obesity in female subjects,the sensitivity and specificity was 96.4%and 55.3%,respectively;when the liver fat content of 5.0%was set as the cut-off value for the diagnosis of fatty liver,the sensitivity and specificity was 83.7%and 43.2%,respectively.Conclusions The indexes of abdominal fat and liver fat measured by QCT in adults receiving physical examination are all positively correlated with body mass index.The effect of QCT in the diagnosis of obesity and fatty liver are both better than body mass index and ultrasound.