Urinary N-acetyl-beta-d-glucosaminidase levels in diabetic adults

Diabetes mellitus (DM) is known to be one of the most common causes of end-stage renal disease. The disease is usually not detected on time, because of the large functioning reserve of the kidney. Currently used markers (serum creatinine, creatinine clearance, urea, and electrolytes) remain relatively normal even when more than 50% of the renal nephron is not functioning. The aim of this study was to determine the level of urinary N-acetyl-beta-d-glucosaminidase (NAG) in diabetic adults in comparison with some currently used markers. A total of 56 diabetic patients between the ages of 23 and 63 were used for this study and 30 nondiabetic between the ages of 18 and 62 were used as control. The diabetic patients were classified into three groups based on how long they have been diagnosed: <2 years (25), 2-5 years (30), and >5 years (25). Spot midstream urine samples were collected into sterile containers, and blood samples were collected into plain tubes. All the analyses were done spectrophotometrically. Creatinine clearance was calculated using the Cockcroft-Gault Equation. There was a significant increase (P < 0.01) in NAG values of 2-5 years and above 5 years and control. The urinary microalbumin concentration of controls was significantly different (P < 0.05) only with those who have had DM for <2 years. Urinary creatinine concentration of control was significantly higher (P < 0.05) than values of all the diabetic groups. There was a significant increase (P < 0.01) in creatinine clearance of control group and those who have had DM for <2 years. It is thus concluded that urinary NAG can be used as an early marker in the diagnosis of diabetic nephropathy since urinary NAG increases first before the other markers analyzed in this current study begins to increase.