Study of Urinary N-Acetyl-Beta-D-Glucosaminidase as a biomarker of Diabetic Nephropathy

Background: Diabetic nephropathy (DN) is a major cause of morbidity and mortality in diabetic patients worldwide. Plenty of tubular damage biomarkers have been discovered. Urinary N-acetyl-β-D-glucosaminidase (NAG) is a hydrolytic enzyme that acts on glycosyl compounds. NAG is excreted in abnormally high amounts in many renal diseases. Objective: The aim of this work was to study the importance of Urinary N acetyl-β-D-glucosaminidase level as an early biomarker for detection of DN and to assess the degree of kidney affection in various stages of DN. Patients and methods: 100 subjects divided into five groups: Group 1: 20 healthy volunteers (control group), group 2: 20 pre diabetic persons, group 3: 20 normo-albuminuria diabetic patients, group 4: 20 micro-albuminuria diabetic patients (ACR 3 -300 mg/mmol) and group 5: 20 macro-albuminuria diabetic patients (ACR ≥ 300 mg/mmol). All individuals were subjected to full history taking, ECG \u0026 echocardiography, abdominal ultrasound, laboratory investigations (HbA1c, fasting and post prandial blood glucose, lipid profile, oral glucose tolerance test (OGTT), blood urea, serum creatinine, serum uric acid, e-GFR and urinary NAG. Results: There was high significant difference between the five groups regarding duration of the disease, fasting blood sugar, postprandial blood glucose, HbA1c, Serum cholesterol, albumin/creatinine ratio, serum urea and creatinine, e-GFR and urinary NAG. In addition, there was significant positive correlation between urinary NAG and albumin/creatinine ratio, blood urea, creatinine, and e-GFR. Conclusion: The urinary NAG can be used as an early urinary biomarker for early detection and progression of diabetic nephropathy in type 2 diabetic patients.