Serum Cystatin C an Early Indicator of Renal Function Decline in Type 2 Diabetes

Objectives: evaluation of cystatin C level in the serum as a predictor of early renal impairment in type 2 diabetic patients. Background: the glomerular filtration rate (GFR) is often estimated from plasma creatinine. Several studies have shown that cystatin C (Cys C) can be used as a better marker for the early detection of renal function decline. Methods: patients were classified according to the urine albumin/creatinine ratio (ACR).Plasma samples were obtained from 20 healthy persons and from 40 patients with diabetes mellitus type 2 for determination of the level of creatinine and cystatin C. Results: There were no significant differences in age and sex between the three groups. However, There was a significant positive correlation between cystatin C and age, A/C ratio, HbA1c, FBS, 2HPP, DM duration and serum creatinine, and there was a significant negative correlation between cystatin C and glomerular filtration rate. eGFR was significantly lower in the macroalbuminuric group than in the micro-albuminuric and normo-albuminuric groups, and cystatin C showed the highest sensitivity and specificity in detecting micro and macro-albuminuria and accordingly early renal function decline in diabetic patients. Conclusion: from this study we concluded that serum cystatin C is a useful, practical, and non-invasive tool for early detection of renal impairment in the course of diabetes.