Cystatin C Levels in Predicting of Nephropathy in Diabetes Mellitus

Aim: The most sensitive and specific measure of functional capacity of the kidney is glomerular filtration rate (GFR). Cystatin C is the most sensitive marker of GFR was shown in recent years. Therefore, we evaluated the cystatin c levels in our patients with diabetic and nondiabetic renal disease. Method: 20 healthy controls, 30 diabetics, 20 patients with chronic renal failure (CRF) and 20 patients with diabetic nephropathy included to the study. Serum cystatin C, creatinine, glucose, HbA1c, blood urea nitrogen levels were measured. Urine albumin, creatinine and microalbumin levels were determined. GFR were calculated in each group. Results: In our study there were significant differences in all parameters between the CRF and diabetic nephropathy groups with DM and control groups (p<0.001). In CRF group there was significant correlation between cystatin C levels and GFR (r = - 0.832) and also the same correlation was observed in diabetic nephropathy group (r = - 0.782) and they were more linear compared to the control group (r = - 0.688).The discrimination of nephropathy of Cystatin C in diabetics and non-diabetics were similar. (ROC AUC area: 987 and 985 respectively) Conclusion: We concluded that monitoring of cystatin C is a significant marker to detect nephropathy in diabetics and has similar diagnostic performance compared to patients with nondiabetic nephropathy.