Article Type

Original Study


Objective The aim of this study was to assess the utility of cystatin C as an early biomarker for acute kidney injury (AKI) compared with serum creatinine. Background Contrast-induced nephropathy (CIN) is a form of AKI that is caused by exposure to contrast media in diagnostic imaging and interventional procedures such as angiography. At present, serum creatinine and creatinine clearance are standard tests for CIN. A few studies have been published that have analyzed the potential use of cystatin C in AKI. Patients and methods We studied 30 diabetic and 20 nondiabetic consecutive patients with normal serum creatinine undergoing coronary angiography (CA). The nondiabetic group was used to assess diabetes as a risk factor for CIN. After providing informed consent, the patients underwent the following before CA: estimation of blood glucose, glycosylated hemoglobin, serum creatinine, blood urea, estimated creatinine clearance, and cystatin C. Serum cystatin C was measured by means of the enzyme-linked immunosorbent assay technique and was evaluated again at 24 h after CA, whereas serum creatinine was evaluated at 24 and 72 h after CA. Results In patients with CIN there was a significant increase in serum cystatin C 24 h after angiography, whereas serum creatinine increased significantly only at 72 h after the procedure. The incidence of CIN was 20% in the diabetic group, 5% in the nondiabetic group, and 14% in the whole population sample. Conclusion The present study highlights the importance of serum cystatin C in detecting AKI associated with contrast administration earlier than serum creatinine.