Stima della velocità di filtrazione glomerulare: confronto tra le equazioni più diffuse basate sulla creatinina.

Introduction: new equations for the estimation of the glomerular filtration rate (eGFR) have been recently proposed. Equation changes may result in differences regarding the Chronic Kidney Disease (CKD) classification of the studied populations. Methods: the serum creatinine-based equations elaborated by Modified Diet for Renal Disease Study (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2009 and 2021, European Kidney Function Consortium (EKFC) were compared for correlation, concordance and effect on CKD staging. Serum creatinine concentration from 38118 consecutive subjects (18 to 75 years, 51% female) were measured by an IDMS traceable method. Results: compared to the 2009 CKD-EPI, the mean difference (limits of agreement) of the MDRD, 2021 CKD-EPI and EKFC equations were -5.8 (-19.3 to 7.8), 3.4 (1.0 to 5.9), -4.9 (-12.6 to 2.7) mL/min x 1.73m² respectively. The concordance, in the same comparisons, was evaluated as excellent (K-Cohen >0.80). The prevalence of CKD [Kidney Disease: Improving Global Outcomes (KDIGO) classes G3a to G5] was 7.6% by MDRD, 5.9% by CKD-EPI 2009, 7.6% by EKFC and 4.8% according to CKD-EPI 2021. The recognized MDRD equation limits regarding age ranges and normal/high eGFR values were confirmed. Discussion: these data confirm that MDRD equation has less accuracy and limited age-related applicability. The other three studied equations demonstrate high level of correlation and very small quantitative differences. However, these differences significantly affect the staging and prevalence of CKD, especially for mild to moderate classes. Awareness of the problem and appropriate communication are required to be addressed before any change to the eGFR equations can be prosed and used. Greater worldwide harmonization of the eGFR would also be desirable. [ABSTRACT FROM AUTHOR]