Plasma glycohydrolase levels in patients with type 1 diabetes at onset andin subjects undergoing an intravenous glucose tolerance test

The effect of hyperglycemia and insulin deficiency on the plasma level of l ysosomal glycohydrolases, namely N-acetyl-beta-D-glucosaminidase, beta-D-gl ucuronidase, alpha-D-galactosidase, and alpha-D-glucosidase, was investigat ed. Two patient groups were assessed: (1) 28 children with type 1 diabetes at onset (fasting blood glucose, 444 +/- 154 mg/100 mt; hemoglobin Al,, 11. 9% +/- 2.4%; symptom duration, 15.9 +/- 8 days; and absence of complication s), (2) 14 adult subjects undergoing an intravenous glucose tolerance test (IVGTT), consisting of 8 non-obese subjects (body mass index, 26 +/- 0.04 k g/m(2); fasting blood glucose, 82 +/- 13 mg/100 mi.; blood insulin, 6 +/- 0 .04 mU/L) and 6 obese subjects (fasting blood glucose, 97 +/-. 3.5 mg/100 m t; blood insulin, 27 +/- 6 mU/L, with normal oral glucose tolerance test). Enzyme activity was determined with the fluorimetric method. The mean level of all evaluated enzymes was significantly increased in patients with type 1 diabetes at diagnosis compared with normal controls. Increased enzyme le vels were also detected in the group of adults undergoing an IVGTT in whom hyperglycemia was accompanied by insulin resistance tie, obese subjects). G lycohydrolase abnormalities appear to be related to insulin deficiency rath er than hyperglycemia. Lysosomal apparatus abnormalities seem to be an inhe rent feature of diabetes that is present at disease onset. The possible rol e of insulin in the regulation of plasma glycohydrolase levels is discussed . Copyright (C) 2000 by W.B. Saunders Company.