Clinical Application Of Glomerular Filtration Rate Assessment Formula In Chinese Population

Objective:To evaluate the applicability of three calculation formulas of glomerular filtration rate in patients with chronic kidney disease(CKD)in China.Methods:A total of 1184 patients who were hospitalized and outpatient at the First Affiliated Hospital of Nanjing Medical University,the Third Affliated Hospital of Sun Yat-sen University,the Affliated Wuxi No.2 Hospital of Nanjing Medical University and the Fourth Hospital of Jilin University from October 2009 to December 2016 were enrolled in this study.GFR was measured by 99mTc-DTPA-labeled renal dynamic imaging(rGFR),the Bias,IQR and accuracy(P30、RMSE)of eGFR and rGFR calculated by four formulas were compared.The diagnostic accuracy of each eGFR and rGFR in CKD was compared by Kappa test.Results:In the overall population,Bias of CKD-EPIscr was the smallest,and CKD-EPIcys was the largest,and the difference was statistically significant.CKD-EPIscr-cys had the best precision and accuracy,P30 was 70.35%.The CKD-EPIscr-cys formula had the smallest bias,precision and accuracy,and P30 was 84.91%,which was statistically significant compared with the other two formulas in the rGFR≥60ml/min/1.73m2 subgroup.In the subgroup of rGFR<60ml/min/1.73m2,CKD-EPIscr formula had the smallest bias.The accuracy of the three formulas was low,and there was no significant difference.In the<60 years subgroup,bias,precision and accuracy of the CKD-EPIscr-cys formula were the best,P30 was 75.71%.There was no significant difference between CKD-EPIscr-cys and CKD-EPIcys.In the≥60 years subgroup,bias of the CKD-EPIscr formula was the least.P30 of the three formulas were less than 70%,and P30 of the CKD-EPIcys formula was the lowest.CKD-EPIscr-cys formula had the highest diagnostic consistency,kappa value was 0.513.Conclusion:The CKD-EPIscr-cys equation is more accurate than the other two equations in chinese,None of the three CKD-EPI equations achieved an ideal accuracy in old participants with moderate-severe impaired GFR.Further improvements for more suitable equations are still needed.Modification of the 2012 CKD-EPI equations for the elderly ChineseBackground:The Chronic Kidney Disease Epidemiology Collaboration(CKD-EPI)reported two equations for estimating glomerular filtration rates(eGFR)based on serum cystatin C(CKD-EPIcys)or serum cystatin C combined with serum creatinine(CKD-EPIscr-cys)in 2012.However,these equations may not be accurate in elderly individuals.We therefore modified the eGFR equations for the elderly Chinese population.Methods:We performed a cross-sectional analyses based on 839 participants aged≥60 years selected from four hospitals located in four different geographic regions of China(Southeast China,Nanjing;East China,Wuxi;South China,Guangzhou;and Northeast China,Changchun)between October 2009 and December 2014.A random sample of 674 participants was used as a training sample set,and the remaining 165 patients were used to test the performances of the equations before and after modification.The equations were modified using a hill-climbing algorithm.99mTc-diethylenetriamine pentaacetic acid(99mTc-DTPA)dynamic renal imaging was used as a reference method for measured GFR(mGFR).Results:Compared with the original CKD-EPI equations,the accuracy assessment indexes(bias,precision,accuracy and misclassification)were obviously improved after modification.Bland-Altman analysis also demonstrated that this modification attempt gained success to some extent.We evaluated CKD stage misclassification by the original CKD-EPI equations and the modified CKD-EPI equations.In CKD stages 3 through 4,there was significant difference in the percentages of misclassification among four equations.Conclusions:The modified CKD-EPIcys and CKD-Epscr-cys equations were more appropriate than the original equations for determining eGFR in elderly Chinese individuals.Further studies are needed to validate these new equations.Objective:To compare the CKD-EPIcys and CKD-EPIscr-cys formulaes and the FAScys formula,the FAScombi formula developed in 2017 in China.Methods:A total of 1184 patients who were hospitalized and outpatient at the First Affiliated Hospital of Nanjing Medical University,the Third Affliated Hospital of Sun Yat-sen University,the Affliated Wuxi No.2 Hospital of Nanjing Medical University and the Fourth Hospital of Jilin University from October 2009 to December 2016 were enrolled in this study.GFR was measured by 99mTc-DTPA-labeled renal dynamic imaging(rGFR),the Bias,IQR and accuracy(P30、RMSE)of eGFR and rGFR calculated by four formulas were compared.The diagnostic accuracy of each eGFR and rGFR in CKD was compared by Kappa test.Results:FAScombi formula had the best performance in overall perticipants,and the difference was statistically significant.In the rGFR≥60 ml/min/1.73m2 subgroup,CKD-EPIscr-cys formula showed slightly better,but there was no significant difference with FAScombi formula.In the rGFR<60 ml/min/1.73m2 subgroup,the FAScombi formula showed the best performance and the differences were statistically significant.At the age of<60 years,the precision and accuracy of the FAScombi formula were better than the other three formulas,but there was no significant difference with the CKD-EPIscr-cys formula.At the age of≥60 subgroup,the FAScombi formula was the most accurate,P30 was statistically different from the other formulas,and>70%.In the diagnostic consistency,the two combined creatinine and cystatin-based formulas were better than the single cysC-based formula,and there was no significant difference in the Kappa values between the two formulas.Conclusion:The accuracy of the FAScombi formula is better than that of the CKD-EPIscr-cys formula in the Chinese population,especially at GFR<60ml/min/1.73m2 and in the elderly population.FAS formula can still be further improved to be more suitable for the Chinese population.