The Combination of Cystatin C and Serum Creatinine Improves the Monitoring of Kidney Function in Patients with Diabetes and Chronic Kidney Disease

Pucci et al. (1) recently reported their study of the use of cystatin C (cysC) to detect decreases in renal function in patients with diabetes. CysC had an advantage over other methods only for detecting very early impairment of renal function [glomerular filtration rate (GFR) < 90 and 75 mL · min−1 · (1.73 m2)−1], whereas detection of the 70 patients with GFR <60 studied by Pucci et al.(1) was not improved by use of cysC compared with conventional estimated GFR estimations (e-GFR) predicted by Cockcroft and Gault (CG) and Modification of Diet in Renal Disease (MDRD) equations. Better GFR estimations are required for those patients considered to have chronic kidney disease (CKD) according to the new American Diabetes Association recommendations, particularly to assess the progression of their CKD, which may not be accurately estimated by the CG and MDRD equations(2). Rule et al.(3) recently proposed a composite GFR estimation based on both serum …