Evaluation of cystatin C for early detection of renal impairment in diabetes

Objective To evaluate cystatin C for early detection of renal impairment in diabetes.Methods The serum cystatin C was detected by immunonephelometric method.The creatinine was measured with a Jaffe rate method.67 diabetic patients with normal creatinine were evaluated for their early renal impairment.Results Significant direct correlations were found between cystatin C and creatinine(r=0.55),and inverse correlations between cystatin C and glomerular filtration rate calculated with the MDRD equation(r=0.48).The area under the receiver operating characteristic curve(0.79) and likelihood ratio(4.3) of cystatin C was better than the area(0.60) and likelihood ratio(1.6) of creatinine.Conclusion In early detection of diabetic renal injury,serum cystatin C can estimate glomerular filtration rate and present a better diagnostic efficiency than serum creatinine.