Serum and urinary activities of beta-N-acetylglucosaminidase and beta-glucuronidase in diabetic patients.

Serum and urinary activities of two acid glycohydrolases, beta-n-acetyl-glucosaminidase and beta-glucuronidase, were significantly higher in a group of diabetic patients when compared to a control group. No significant differences were found between patients without vascular complications and those with retinopathy and/or large vessel disease, while the highest enzyme levels were present in diabetics in poor metabolic control. In diabetics with nephropathy, urinary excretion of both enzymes was further increased, so that the serum/urine activity ratio (greater than 1 in normal subjects and in diabetics without nephropathy) was inverted (less than 1). These data seem to show that the high activity of these enzymes, commonly observed in diabetes mellitus, is related to the illness rather than to its vascular complications, being higher in patients in poor metabolic control. Furthermore serum/urine activity ratio may be a useful indicator in the monitoring of diabetic nephropathy.