Cystatin C- An Early Diagnostic Biomarker of Diabetic Kidney Disease

Aim: This study aimed to evaluate serum cystatin C vs. Serum creatinine and BUN as a potential better marker for early diagnosis of diabetic kidney disease.

Study Design: Cross-sectional study.

Place and Duration of Study: Department of Biochemistry, LTM Medical College, Sion, Mumbai, between January 2014 and November 2014.

Methodology: Diagnosed patients of type 2 diabetes mellitus were evaluated based on detailed history, clinical examination and laboratory investigations. Patients having frank proteinuria were excluded. Patients without proteinuria were tested for microalbuminuria. In study group, we included 50 patients having microalbuminuria and in control group, 50 patients without microalbuminuria. Blood urea nitrogen (BUN), serum creatinine and serum cystatin C were estimated. Results were analysed by unpaired t-test & P-value was determined.

Results: Serum cystatin C was found to be increased in the study group as compared with controls and the difference was statistically significant (P = .000). BUN (P = .26) and serum Creatinine (P = .11) were found to be slightly higher in cases compared to control group but values were within reference range.

Conclusion: The results of this study suggest that serum cystatin C measurement is a useful, practical tool for the evaluation of renal involvement in the course of diabetes. BUN and serum creatinine values are affected by many factors like age, sex, muscle mass, diet. Serum cystatin C estimation offers a hope that diabetic kidney disease can be well prevented with appropriate interventions.