ABSTRACT
Background: diabetic nephropathy [DN] is a serious complication of diabetic mellitus associated with increased risk of morbidity and mortality. Diagnostic markers to detect DN at early stage are important as early intervention can slow loss of kidney functions and improve patient outcomes. N-acetyl Beta d-glucosaminidase [NAG] is a lysosomal enzyme, present in high concentrations in renal proximal tubular cells, Gamma-glutamyltransferase [GGT] is an enzyme which located along the proximal tubular brush border, Malondialdehyde [MDA] is a highly toxic product, formed in part by lipid oxidation derived free radicals, Reactive carbonyl derivatives [RCD[S]] is an oxidative stress marker in urine, as a measure of the oxidative modification of proteins and beta-2-microglobulin is filtered by the glomerulus, absorbed and catabolized by the proximal tubules. The aim of this study is to investigate the urinary outcome of these markers as early detectors of diabetic nephropathy in type 1 diabetic children
Subjects and methods: This case-control study included 67 children with type 1 diabetes mellitus [33 male; 34 female], age [11.03 +/- 1.05 years] and thirty one age [10.58 +/- 1.11 years] and sex [13 male; 18 female] matched healthy children [13 male; 18 female]. Type 1 diabetic children were further subdivided into microalbuminuric and normoalbuminuric subgroups according to microalbuminuria concentration [30 mg/ g creatinine]. Age, sex, diabetic duration and the current daily insulin dose, and family history of diabetes, weight, height, body mass index, systolic and diastolic blood pressure were recorded. Fasting plasma glucose, glycated hemoglobin, blood urea nitrogen, plasma creatinine, urinary creatinine, micoalbumin, N-acetyl-B-D glucosaminidase [NAG], Gama glutamyl transferase [GGT], Beta-2-microglobulin, Malondialdehyde [MDA] and Reactive carbonyl groups [RCDS[S]] were measured in all subjects
Results: a significant increase in tubular injury markers of diabetes [NAG, GGT, beta-2-microglobulin] and oxidative stress parameters [MDA, RCDS[S]] as compared to control subjects was found. Microalbuminuric subjects showed a significant elevatation in the urinary markers including NAG, GGT, beta-2-microglobulin, MDA, RCDS[S] as compared to normoalbuminuric subjects. The studied urinary tubular enzymes [NAG, GGT], oxidative stress markers [MDA, RCDS[S]] and Beta-2- microglobulin showed positive correlations with one another
Conclusion: The results of this study introduced the possibility of depending on tubular enzymes [NAG, GGT], oxidative stress markers [MDA, RCDS[S]] and Beta2 microglobulin as early, reliable, and sensitive predictors for diabetic nephropathy. The NAG activity index proved to be the most sensitive biomarker, then beta-2- microglobulin for early discovering the tubule cells damage