Accuracy evaluation of 2021 Chronic Kidney Disease Epidemiology Collaboration, Full Age Spectrum and European Kidney Function Consortium equations for estimating glomerular filtration rate in type 2 diabetes mellitus and healthy adults

Background and aims: Estimated glomerular filtration rate (eGFR) equations accuracy has been questioned in diabetes mellitus (DM). We aimed to evaluate the performance of three equations - European Kidney Function Consortium (EKFC), Full Age Spectrum (FAS), and 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) - in healthy and type 2 DM participants.

Material and methods: This cross-sectional studycompared eGFR equations withareference method: measured GFR (mGFR) by ⁵¹Cr-EDTA. The equations performance was assessed usingBland-Altman plot,concordance correlation coefficient (CCC), bias,P30 andP15 accuracy.

Results: In the 100 healthy adults included (aged 39 ± 15 years, 67% women, mean mGFR 107 ± 15, 2021 CKD-EPI 109 ± 14, FAS 107 ± 18 and EKFC 101 ± 12 mL/min/1.73 m²), all equations reached P30 accuracy above the desirable benchmark of 90%. In the 122 patients with type 2 DM (aged 61 ± 10 years, 55% women, mGFR97 ± 22, 2021 CKD-EPI 86 ± 20, FAS 83 ± 25 and EKFC 79 ± 18 mL/min/1.73 m²), the equations presented larger biases, worst agreement with mGFR and inferior accuracy, with 2021 CKD-EPI (83%) and EKFC (82%) presenting greater P30 than FAS (77%).

Conclusion: In healthy Brazilian adults, 2021 CKD-EPI, FAS and EKFC are suitable to estimate GFR. However, all equations underperform in people with type 2 DM.