Correlation of Urinary N-Acetyl-beta-D-Glucosaminidase with Albuminuria in Type-II Diabetic Patients

Abstract

Background: Urinary N-acetyl-β-D-Glucosaminidase (NAG) level, if raised shows tubular damage in type-II diabetics. Its positive correlation with albumin creatinine ratio (ACR) at microalbuminuria stage of nephropathy, suggests role as early screening marker. With these objectives, we determined correlation of urinary NAG activity with albuminuria in both normoalbuminuric & microalbuminuric type-II diabetics and sensitivity of this biomarker as a screening test.
Methods: In this cross-sectional analytical study of 6 months on 86 type-II diabetics, subjects with less than 10 years duration of diabetes were included and those with macroalbuminuria, other kidney disease, and comorbidity were excluded. Study subjects were grouped into normoalbuminuria (group 1) &
microalbuminuria (group 2). Correlation of urinary NAG to creatinine ratio (NCR) with ACR and their sensitivity were determined. Results: Out of all, group 1 and group 2 included 42 and 44 subjects with male to female ratio 2:1 & 1.6:1 respectively. We found lower mean levels of both urinary NCR and ACR in group 1 than in group 2 (P <0.00). In both groups they were positively correlated (r=0.65 in group 1 & r=0.53 in group 2). 95% of subjects with nephropathy were identified by NCR while only 51% by ACR. Conclusion: Levels of urinary NAG were more positively correlated with urinary albumin in normoalbuminuric than microalbuminuric type-II diabetics. It was more sensitive to detect nephropathy than microalbuminuria level when used as a screening test.