Comparative Evaluation of Cystatin C and Conventional Renal Markers for Early Detection of Renal Dysfunction in Type 2 Diabetes Mellitus (T2DM).

Abstract

Background:

 Early detection of renal functional changes in type 2 diabetes mellitus (T2DM) is essential to prevent progression to chronic kidney disease. Conventional renal biomarkers such as serum creatinine and urea often fail to detect early impairment because they typically rise only after substantial loss of renal function. This study evaluated whether serum cystatin C provides greater sensitivity for identifying early renal functional changes in T2DM.

Methods:

 A comparative cross-sectional study was conducted involving 30 patients with T2DM and 30 healthy controls aged 30-70 years with comparable sex distribution. Serum levels of random blood sugar (RBS), glycated haemoglobin (HbA1c), urea, creatinine, and cystatin C were measured. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Statistical analyses were performed using SPSS version 25.

Results:

 The T2DM group showed significantly higher levels of RBS (220.10 ± 92.9 mg/dL), HbA1c (8.68 ± 1.7%), urea (24.23 ± 13.4 mg/dL), and cystatin C (1.25 ± 0.6 mg/L) compared with controls (p = 0.001 for RBS, HbA1c, and cystatin C; p = 0.01 for urea). Serum creatinine and eGFR did not differ significantly between groups. Receiver operating characteristic analysis demonstrated superior discrimination for cystatin C (AUC = 0.78) compared with urea (AUC = 0.63) and creatinine (AUC = 0.55).

Conclusion:

 Serum cystatin C demonstrated greater sensitivity than conventional renal markers for detecting early renal functional changes in T2DM and may complement routine renal assessment.