内脏脂肪指数对瘦型人群中非酒精性脂肪性肝病的预测价值:一项横断面研究

Predictive value of visceraladiposity index in nonalcoholic fatty liver disease in lean population:a cross-sectional study

目的探究内脏脂肪指数(visceral adiposity index,VAI)与瘦型人群中非酒精性脂肪性肝病(nonalcoholic fatty liver disease,NAFLD)的相关性及其预测价值。方法随机纳入2020年6月-2021年5月西安交通大学第二附属医院2576名健康体检者,身体质量指数(BMI)正常(即<24 kg/m^(2)),分为瘦型NAFLD组(n=213)与健康对照组(n=2363),根据VAI四分位数由低到高分为Q 1~Q 4组,比较组间生化指标差异与NAFLD患病情况。采用限制性立方样条分析VAI与瘦型NAFLD之间关系,Logistic回归与受试者工作特征(ROC)曲线探究VAI对瘦型NAFLD的预测价值。结果共纳入2576名体检者,瘦型NAFLD患病率为8.3%(213例)。Q 1~Q 4组平均年龄、男性占比、BMI与腰围(waist circumference,WC)显著增加,且呈明显剂量反应关系(均P<0.001)。与Q 1组相比,Q 2~Q 4组收缩压、舒张压、白细胞计数、血红蛋白浓度、谷丙转氨酶、谷草转氨酶、γ氨基转肽酶、碱性磷酸酶、总胆固醇、三酰甘油、低密度脂蛋白胆固醇、血尿酸与空腹血糖水平均明显增加,直接胆红素与高密度脂蛋白胆固醇水平则逐渐降低,组间差异均具有统计学意义(P<0.001)。Q 1~Q 4组NAFLD的患病率分别为0.6%、3.3%、7.0%、22.2%,呈显著递增(P<0.001)。限制性立方样条图显示随着VAI增加,瘦型人群中NAFLD的患病风险显著增加(P<0.001),两者之间存在非线性关系(P for nonlinear<0.001)。Logistic回归结果显示,在调整各混杂因素后,Q 2、Q 3、Q 4组瘦型NAFLD的患病风险仍分别为Q 1组的2.926倍(95%CI:0.971~8.811)、3.435倍(95%CI:1.154~10.230)与5.920倍(95%CI:1.873~18.719)。ROC曲线显示,VAI对于瘦型NAFLD具有较好的预测价值,曲线下面积为0.815,临界值为1.532,诊断敏感性为77.9%,特异性为72.8%,均优于BMI与WC。结论瘦型体检人群中VAI升高与NAFLD发病风险显著相关,具有良好预测价值,可用于瘦型NAFLD早期筛查与诊断。

Objective To explore the association between visceral adiposity index(VAI)and nonalcoholic fatty liver disease(NAFLD)in lean population and the predictive value of VAI.Methods A total of 2576 healthy subjects,body mass index(BMI)<24 kg/m^(2),from The Second Affiliated Hospital of Xi’an Jiaotong University from June 2020 to May 2021 were randomly included and divided into lean NAFLD(n=213)and healthy control group(n=2363).According to the VAI quartiles,they were divided into Q 1-Q 4 groups from low to high.The differences in biochemical parameters and the prevalence of NAFLD were compared among groups.The correlation between VAI and lean NAFLD was analyzed with restricted cubic spline(RCS),and the predictive value of VAI was explored by Logistic regression and receiver operating characteristic(ROC)curve.Results A total of 2576 participants were included,and the prevalence of lean NAFLD was 8.3%(213 cases).The mean age,male ratio,BMI and waist circumference(WC)from group Q 1 to group Q 4 were significantly increased in a dose-response relationship(all P<0.001).Compared with those in group Q 1,systolic blood pressure,diastolic blood pressure,white blood cell count,hemoglobin concentration,alanine aminotransferase,aspartate aminotransferase,γ-glutamyl transpeptidase,alkaline phosphatase,total cholesterol,triglyceride,low-density lipoprotein cholesterol,blood uric acid,and fasting blood glucose levels in groups Q 2 to Q 4 were significantly increased,while direct bilirubin and high-density lipoprotein cholesterol levels were gradually decreased(both P<0.001).The prevalence rate of NAFLD in groups Q 1-Q 4 was 0.6%,3.3%,7.0%and 22.2%,respectively(P<0.001).RCS showed that the risk of NAFLD in lean population rose significantly with the increase of VAI(P<0.001),and there was a nonlinear relationship between them(P for nonlinear<0.001).Logistic regression showed that after adjusting other confounding factors,the risk of lean NAFLD in groups Q 2,Q 3 and Q 4 was still 2.926 times(95%CI:0.971-8.811),3.435 times(95%CI:1.154-10.230),and 5.920 times(95%CI:1.873-18.719)that Q 1 group.ROC curve showed that VAI had a good predictive value for lean NAFLD,with area under the curve of 0.815,critical value of 1.532,diagnostic sensitivity of 77.9%and specificity of 72.8%,which were better than BMI and WC.Conclusion VAI is significantly associated with the risk of NAFLD in lean population,and thus has a good predictive value.It can be used for early screening and diagnosis of lean NAFLD.