Applicability Of Different Glomerular Filtration Rate Evaluation Equations In Patients With Nonalcoholic Fatty Liver Disease

Objectives:The purpose of this study was to verify the diagnosis performance of different glomerular filtration rate evaluation（e GFR）equations in patients with non-alcoholic fatty liver disease（NAFLD）,and to show whether the existing e GFR equations are suitable for NAFLD population and which equation is more suitable for evaluating renal function in NAFLD population.Methods:The data of adult NAFLD patients who were hospitalized in Fujian Provincial Hospital from January 2017 to June 2019 were collected.The measuerd glomerular filtraion rate（m GFR）obtained by the ^99mTc-diethylenetriaminepentaacetic acid was used as the reference standard.Respectively compared bias、accuracy、30%coincidence、root mean square error of Cockcroft-gault equation、the Modification of diet in renal disease study group-chinese（MDRD-CN）equation、the Chronic kidney disease epidemiology collaboration（CKD-EPI）equation and CKD-EPI equation2（an Modified CKD-EPI equation in diabetic population）in the overall population、m GFR<60ml/min/1.73m² group and m GFR≥60ml/min/1.73m² group.The Bland-Altman analysis method was used to compare the consistency between the four evaluation equations and the reference standard.The area under the ROC curve was used to evaluate the ability of different e GFR equations to diagnosed m GFR<90ml/min/1.73m² and m GFR<60ml/min/1.73m².Results:Finally,190 patients with NAFLD were included.Statistical analysis found that in the whole population,the bias of CKD-EPI equation2 was-2.21ml/min/1.73m²,the absolute value of which was lower than that of the other three equations and the difference was significant（p<0.001）;the interquartile range was 22.47 ml/min/1.73m²,and the root-mean-square error is 15.99,which was lower than the other three e GFR equations;the30%coincidence rate is 84%,which was higher than the other three equations and the difference is significant（p<0.001）.In the group of m GFR<60ml/min/1.73m²,the bias of CKD-EPI equation2 was-9.21 ml/min/1.73m²,the absolute value of which was higher than that of C-G equation and CKD-EPI equation,the difference was not significant（p>0.05）;the interquartile range was 12.85 ml/min/1.73m² and the root mean square error was 17.31,which was lower than that of the other three e GFR equations.The 30%coincidence rate was 67%,which was higher than that of the other three equations,the difference was significant（p<0.001）.In the group of m GFR≥60ml/min/1.73m²,the bias of CKD-EPI equation2 was 4.58ml/min/1.73m²,the absolute value was lower than that of the other three e GFR equations and the difference was significant（p<0.001）,the interquartile range was 22.97 ml/min/1.73m²,which was lower than that of CKD-EPI equation but higher than that of C-G equation and MDRD-CN equation,and the root mean square error was 15.33,which was lower than that of the other three e GFR equations.The 30%coincidence rate was 92%,which was higher than that of the other three equations and the difference was significant（p<0.001）.The MDRD-CN equation showed the largest bias,interquartile range and the lowest 30%coincidence rate in all three groups.Bland-Altman analysis showed that that the consistency limits of e GFR and m GFR calculated by the four e GFR equations were all more than 60ml/min/1.73m²,CKD-EPI equation2 shows the least range,11 cases（6.3%）exceeded the 95%consistency limit.The area under the ROC curve for m GFR<60ml/min/1.73m² and m GFR<90ml/min/1.73m² for the four equations were all greater than 0.80,and there was no statistically significant difference between groups（p>0.05）Conclusions:None of the four eGFR equations can accurately estimate the glomerular filtration rate of NAFLD patients.Further research is needed to find a more suitable e GFR equation for NAFLD patients.In the absence of a better evaluation equation,CKD-EPI equation 2can be used preferentially to estimate glomerular filtration rate in NAFLD patients.