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

•2021 CKD-EPI, FAS and EKFC equations are suitable to estimate GFR in healthy adults.•All equations reach the benchmark of P30 accuracy >90% in healthy participants.•2021 CKD-EPI, FAS and EKFC have larger biases and inferior accuracy in type 2 DM.•These equations are unreliable to represent GFR in people with type 2 DM.•2021 CKD-EPI and EKFC have higher P30 accuracy than FAS. 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. 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. 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%). 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.