Glomerular filtration rate estimation: concordance of the 2020 European Kidney Function Consortium equation with CKD-EPI and FAS in young adults.

Abstract

Introduction. The estimation of the GFR (eGFR) is carried out by equations. Most of them are applicable with in an age range. Discrepancies between the values are found when crossing a limit of age. CKD-EPI overestimates GFR in young adults; FAS overestimates it for low creatininemias. To minimize these limitations, the European Kidney Function Consortium proposed the EKFC equation that combines design features of FAS and CKD-EPI.

Objective. The performance of EKFC vs. CKD-EPI and FAS in young people wase valuated: differences in eGFR and agreement in the allocation to GFR categories were found.

Methods. Analytical study approved by the Ethics Committee. Sample: 157 volunteer students, 18-37 years old. Creatininemia: kinetic Jaffé method traceable to Isotopic Dilution Mass Spectroscopy. Program: MedCalc.

Results. EKFC: eGFR lower than CKD-EPI and FAS, total and by sex.

Means of the differences (mL/min/1.73m²): total (CKD-EPI - EKFC) = 10.42; 18-20 years = 11.91; 21-30 years = 11.10; 31-37 years = 8.96 // (FAS-EKFC) total = 2.79; FAS? 110 mL/min/1.73m² and higher: 1.1 and 9.0 respectively.

Allocation to G categories: lower kappa EKFC vs. CKD-EPI than vs. FAS. Recategorization: 13.4% in G1 by CKD-EPI categorized G2 by EKFC; 0.6% compared to FAS, in the same sense. Allocation to categories ?75mL/min/1.73 m² or less: good agreement.

Conclusions. In the sample, EKFC metes the objectives of its design. The overestimation of eGFR by CKD-EPI in young adults decreased, even more around 18 years of age, and corrected that of FAS for low creatininemias. It is clinically and epidemiologically important to develop GFR estimators based on creatininemia that cover the entire range of ages and renal function status.