Serum Cystatin C: An Innovative Biomarker for Early Renal Impairment in Diabetes

Background: Diabetic nephropathy has been identified as one of the primary contributors to chronic kidney disease (CKD) in the world today. Conventional indicators of early renal impairment such as serum creatinine and microalbuminuria, are often missed. Serum cystatin C (CysC) is perhaps one of indicators of an early glomerular dysfunction. Objective: To assess the diagnostic value of serum cystatin C for detection of early renal impairment in individuals with type 2 diabetes mellitus (T2DM). Methods: This cross-sectional analytical study entailed 150 participants; 75 of them were healthy controls (HCs), whereas 75 suffered type 2 diabetes. Renal functioning was determined by serum creatinine (SCr), urine albumin creatinine ratio (UACR), assessed glomerular filtration rate (eGFR), CysC. Statistical comparisons and correlation analysis were made. Results: The CysC levels of T2DM patient have been found to be significantly higher compared to controls (p < 0.001). Even with normal serum creatinine, normoalbuminuric diabetic patients still had high cystatin C levels (p < 0.01). The relationship of cystatin C with eGFR was more negative than that of creatinine (r=-0.72 and r=-0.58, respectively). Conclusion: CysC is accurate and sensitive biomarker of early renal deterioration in diabetic individuals that could help with earlier management before nephropathy would become evident.