Study of CystatinC as Early Biomarker of Nephropathy in Patients with Type 2 DM and Risk Stratification in TarnakaHospital of Hyderabad City in India

This study was done to evaluate clinical usefulness of cystatin C levels of serum and urine in predicting renal impairment in normoalbuminuric patients with type 2 diabetes and to evaluate the association between albuminuria and serum/urine cystatin C. Type 2 diabetic patients (n = 200) with normoalbuminuria (n = 45), microalbuminuria (n = 83) and macroalbuminuria (n = 42) were enrolled. Creatinine, urinary albumin levels, serum/urine cystatin C and estimated glomerular filtration rate (eGFR by MDRD (Modification of Diet in Renal Disease) and CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration] equations)) were determined. The cystatin C levels of serum and urine increased with increasing degree of albuminuria, reaching higher levels in macroalbuminuric patients (p< 0.001). In multiple regression analysis, C-reactive protein (CRP), sex, albumin-creatinine ratio (ACR) and eGFR affected serum cystatin C. Urine cystatin C was affected by triglyceride, age, eGFR and ACR. In multivariate logistic analysis, cystatin C levels of serum and urine were identified as independent factors associated with eGFR< 60 mL/min/1.73 m² estimated by MDRD equation in patients with normoalbuminuria. On the other hand, eGFR< 60 mL/min/1.73 m² estimated by CKD-EPI equation was independently associated with low level of high-density lipoprotein in normoalbuminuric patients. The cystatin C levels of serum and urine could be useful markers for renal dysfunction in type 2 diabetic patients with normoalbuminuria.