[Influence of glycemic blood glucose control and incipient diabetic nephropathy on the urinary excretion of N-acetyl-glucosaminidase (NAG) in diabetes mellitus].

Plasma glucose, glycated hemoglobin lc (HbAlc), urinary albumin excretion rate (AER) and urinary N-acetyl-glucosaminidase (NAG): creatinine ratio were studied in 100 normotensive diabetic patients with no evidence of overt renal disease and in 45 controls, to find out whether the glycaemic control and incipient nephropathy may influence the urinary excretion of NAG. Twenty-three of the diabetics had microalbuminuria (group II). Group I comprised the 77 diabetics without microalbuminuria. The groups I and II of diabetics were divided into two according to plasma glucose were greater o smaller to 140 mg/dl. The group I of diabetics had greater NAG: creatinine ratio than controls, too (0.41 +/- 0.24 and 0.16 +/- 0.08 mu/mmol creatinine, p < 0.0005); in this group urinary NAG was found to positively correlate with plasma glucose and creatinine (p < 0.0005, r = 0.45). Multiple regression analysis was performed in the whole of diabetics and significant association were identified between urinary NAG excretion and plasma glucose, AER and plasma creatinine (p < 0.0005, r = 0.42). The diabetics with plasma glucose lower to 140 mg/dl had more important correlation NAG: creatinine ratio-AER (p < 0.0001, r = 0.70). It is concluded that measurement of urinary NAG may be of value in the detection of diabetic nephropathy at a potentially reversible stage if the plasma glucose is take into account.