Performance of the Chronic Kidney Disease Epidemiology Collaboration Equation to Estimate Glomerular Filtration Rate in Diabetic Patients

OBJECTIVE: The best method to estimate glomerular filtration rate (GFR) in diabetic patients is still largely debated. We compared the performance of creatinine-based formulas in a European diabetic population. RESEARCH DESIGN AND METHODS: We compared the performance of Cockcroft and Gault, simplified Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology (CKD-EPI) Collaboration equations in 246 diabetic patients by calculating the mean bias and the interquartile range (IQR) of the bias, 10% (P10) and 30% (P30) accuracies, and Bland-Altman plots. GFR was measured by inulin clearance. RESULTS: For the whole population, the IQR was slightly lower for CKD-EPI, but the mean bias was lower and P10 and P30 were higher for MDRD. Similar results were observed in specific subgroups, including patients with mild renal insufficiency, obese patients, or type 2 diabetic patients. CONCLUSIONS: In our population, the CKD-EPI formula does not exhibit better performance than the simplified MDRD formula for estimating GFR.