Urinary Enzymes as Early Diagnostic Marker for Diabetic Nephropathy: A Comparison with Cystatin C

Abstract

Background: Renal damage is a serious major microvascular diabetic complication leading to the death of diabetic patients. Thus, diagnosis of diabetic nephropathy in an earlier stage would be critical. Urinary enzymes which are markers of tubular damage viz. urinary GGT/ALP/LDH and their creatinine standardized ratio can serve as cost effective, feasible, widely available early diagnostic markers for diabetic nephropathy Materials and Methods: Study enrolled 60 subjects for each group. Measurement of fasting blood sugar, random blood sugar, serum urea, serum creatinine, and serum cystatin c were done in serum. Measurement of ALP, LDH, GGT was done in urine. Results: The urinary enzyme levels were significantly high in patients of diabetic nephropathy in comparison to other study subjects. Correlation analysis of Urine Albumin Creatinine Ratio and Urine ALP (r value- -0.1, p value-<0.0001), and Urine GGT (r value- -0.2, p value- <0.0001) Urine LDH (r value- -0.3, p value- <0.0001) of patients suffering from Diabetic Nephropathy was performed using Pearson’s correlation analysis. Correlation analysis of Serum Cystatin C and Urine ALP (r value- 0.2, p value-<0.0001), Urine LDH (r value- 0.01, p value- <0.0001), and Urine GGT (r value- 0.14, p value-<0.0001) of patients suffering from Diabetic Nephropathy was performed using Pearson’s correlation analysis. Conclusion: Correlation studies of urinary enzyme levels with albumin-creatinine ratio (urine) and cystatin C (serum) levels didn’t show any strong correlation (positive or negative) among the enzyme’s levels with established markers of diabetic nephropathy. Given the fact that urinary enzyme levels are increased in case of tubular dysfunction of the nephrons, the result of our study show that, diabetic nephropathy primarily affects the glomerular function.