Comparison of four eGFR equations in assessing complications associated with chronic loss of kidney function: A cross-sectional study in a Chinese population
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There are various equations for estimating glomerular filtration rate (eGFR), mainly including abbreviated Modification of Diet in Renal Disease Study Equations (aMDRD), c-aMDRD for the Chinese population, Chronic Kidney Disease Epidemiology Collaboration Equation (CKD-EPI 2009) and Creatinine-Cystatin C equation (CKD-EPI 2012). Currently, it is unclear which eGFR equation more realistically predicts and reflects the development of complications closely associated with chronic loss of kidney function. Our study selected a total of 1,012 nondialysis patients at stages 2 through 4 chronic kidney disease (CKD) to assess these complications using eGFR calculated by these four equations. Receiver operating characteristic (ROC) analysis was used to analyze various metabolic complications and compare the areas under the curve. The results showed that the most widely applied equation, eGFRcreat-cys, had equal or better sensitivity and specificity in assessing four complications (anemia, hyperphosphatemia, hyperparathyroidism, and metabolic acidosis) as compared to the other three equations. The eGFRcreat-cys thresholds for detecting complications with 90% sensitivity were 47.4, 37.5, 25.7, and 37.8 mL/min/1.73m2 for anemia, hyperphosphatemia, hyperparathyroidism, and acidosis, respectively. The results of net reclassification improvement (NRI) and integrated discrimination improvement (IDI) showed that the eGFRcreat-cys equation was better or not worse than the other three equations for screening the four complications. In summary, timing the onset of CKD-associated complications is an important step for delaying their progression. Our study showed that the CKD-EPI 2012 had an optimal correlation with complications associated with loss of kidney function. We suggest that CKD-EPI 2012 should be used for early detection of CKD-associated complications to minimize the missed diagnosis rate in the Chinese population.