The Study On The Methods Of GFR Evaluation And Analysis Of Influential Factors

Background:Chronic kidney disease?CKD?has become an increasingly serious health problem worldwide,which leads to a heave economic burden for both society and families.Glomerulonephritis is currently the leading cause of CKD in Chinese population.With an increasing prevalence of type 2 diabetes mellitus?T2DM?,it is expected to become the main pathogenic factor of CKD.Early detection of renal dysfunction and the targeted therapy can help to prevent deterioration of renal function.Glomerular filtration rate?GFR?is an important indicator of renal function assessment.Different equations for calculating estimated GFR?eGFR?have their own characteristics in clinical application.The objective of this study was to investigate the accuracy of different renal function evaluation methods by comparing eGFR values calculated by six equations separately with reference GFR?rGFR?measured by 99Tcm-DTPA,offering further guidance for clinical practice.Objective:The objective of this study was to identify the optimal equation among six equations that accurately estimated the GFR and CKD stage in Chinese CKD patients and T2DM patients,and to explore the factors that might influence GFR in T2DM patients.Methods:A total of 1422 CKD patients?part one?and 403 T2DM patients?part two?were enrolled in this study.Data of 234 T2DM patients from part two were reviewed for analysis of influential factors?part three?.The eGFRs calculated separately by three Diet in Renal Disease?MDRD?equations and three Chronic Kidney Disease Epidemiology Collaboration?CKD-EPI?equations were compared with the rGFR measured by the 99Tcm-DTPA renal dynamic imaging method.Results:There was a close correlation between rGFR and serum creatinine?Scr?as well as cystatin C?Cys-C?.Bland-Altman analysis showed that eGFR_cys and eGFR_scrcys performed similarly,and achieved the tightest limits of agreement among the six equations in CKD group and T2DM group.eGFR_cys and eGFR_scrcys in sequence achieved the first and second highest 30%and 50%accuracies.The 30%and 50%coincidence rates of eGFR_cys with rGFR was 54.4%and 78.9%in CKD group and 61.5%and 87.8%in T2DM group,respectively;eGFR_scrcys equation had the second high coincidence rates,which were 51.6%and 76.4%in CKD group and 58.6%and 85.1%in T2DM group,respectively.The agreement between rGFR and eGFR_scr was better than with other Scr-based equations?MDRD equations?in both CKD group and T2DM group.Overall,the use of a equation based Scr and Cys-C(eGFR_scr^cys)could improve the bias of eGFR and achieve the highest diagnostic accuracy for renal insufficiency,with the largest area under curve of ROC6o,on which basis the cutoff point of 58.1 ml/min/1.73 m² in CKD group and 57.2 ml/min/1.73 m² in T2DM group,more accurate than other equations for the diagnosis of chronic renal insufficiency?as clinically diagnostic criteria of<60.0ml/min/1.73 m²?.eGFR calculated by each equation has similar accuracy in CKD stage between CKD group and T2DM group,as follows:each subgroup has high accuracy??84.2%,except eGFR_MDRD,78.9%?at CKD 5 stage;Scr-based equations had a high accuracy for the diagnosis of CKD 1 stage??90.4%?which was superior to eGFR_cys or eGFR_scrcys?72.5-84.5%?;the accuracy in each subgroup was barely satisfactory or moderate for predicting other stages.Based on the overall performance,eGFRsc_cys had the highest accuracy for CKD stage classification with the highest kappa value?0.416?in CKD group;whereas eGFRa_MDRD and eGFR_scrcys achieved the highest and secondary kappa value?0.417 and 0.404,respectively?among T2DM population with age ?18 years old;the eGFR_scrcys achieved the highest kappa value?0.423?among diabetic patients with 18-65 years old.The CKD-EPI equations were superior to MDRD equations in T2DM patients in all age groups.However,the diagnostic value fluctuated greatly in the elderly group?>65 years old?.In T2DM group,BMI,Scr and Cys-C were independent negative factors of chronic renal insufficiency;age was an independent negative factor in Scr group,but not in Cys-C group;high density lipoprotein was a protective factor against chronic renal insufficiency.Age,BMI,Scr and Cys-C were associated with CKD stage classification in T2DM patients.Uric acid was a negative factor leading to advanced CKD stage in T2DM patients of Scr group.Conclusion:CKD-EPI_scrcys has the highest agreement?except CKD-EPIcys?and smallest bias with rGFR.It also exhibits good diagnostic value for the diagnosis of chronic renal insufficiency and relative high accuracy in CKD staging.The CKD-EPI equations were superior to MDRD equations in T2DM patients with different ages,but the age had an impact on the diagnostic efficiency of the CKD-EPI and MDRD equations.Except Scr and Cys-C,there are still other influential factors that affect chronic renal insufficiency and CKD stage classification in T2DM patients.