title: Serum cystatin C assay for the detection of early renal impairment in diabetic patients.
abstract: The ability to assess renal function in diabetes patients rapidly and early is of major importance. This study was designed to determine whether cystatin C can replace serum creatinine as the screening marker for reduced glomerular filtration rate (GFR) in type 2 diabetes patients. The study was performed on 51 type 2 diabetic patients. GFR was estimated by the plasma clearance of (99m)Tc-DTPA. The correlation between (99m)Tc-DTPA clearance and levels of serum cystatin C, serum creatinine, and creatinine clearance was determined. Sensitivity and specificity for the diagnosis of renal impairment (defined as GFR<68 ml/min) were calculated by a receiver operating characteristic (ROC) curve for serum cystatin C, serum creatinine, and creatinine clearance. The correlation coefficients with (99m)Tc-DTPA clearance were -0.744 for serum cystatin C, -0.658 for serum creatinine, and +0.625 for creatinine clearance (P<0.001). With a cutoff value of 68 mL/min, the area under the ROC curve (AUC) was 0.891 for cystatin C, 0.77 for creatinine, and 0.753 for creatinine clearance. The AUC was statistically different between serum cystatin C and creatinine clearance (P<0.05). The ROC plot indicates that cystatin C is superior to serum creatinine and creatinine clearance for detecting impaired GFR. Serum cystatin C appropriately reflects GFR in diabetes, and is more efficacious than serum creatinine and creatinine clearance in detecting reduced GFR in type 2 diabetes patients.
authors.affiliation: Department of Clinical Laboratory, Peking University First Hospital, Beijing, China.
authors.forename: Li Hai
authors.initials: LH
authors.lastname: Xia
authors.forename: Xu Guo
authors.initials: XG
authors.lastname: Bing
authors.forename: Xia Tie
authors.initials: XT
authors.lastname: An
mesh_terms: D000328:Adult; D015415:Biomarkers; D003404:Creatinine / Q000097:blood; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000000981:diagnostic imaging*; D003928:Diabetic Nephropathies / Q000097:blood* / Q000000981:diagnostic imaging*; D042241:Early Diagnosis; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D019275:Radiopharmaceuticals; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate