[Levels of free fatty acids in plasma, tissue utilization coefficient of glucose K and insulin secretion following intravenous glucose load in hyperthyroid patients treated with propranolol or acebutolol].

The study aimed at determining relationship between plasma free fatty acid (FFA) and impaired glucose tolerance in hyperthyroid patients prior to and after the treatment with propranolol or acebutolol, i.e. following lipolytic blockade leading to a decrease in plasma FFA levels. The study included 31 untreated hyperthyroid patients and 12 normal subjects serving as a matched control group. IVGTT was performed in all subjects. Venous blood specimens were collected at 0, 3, 5, 15, 30, 60, and 120 minutes following intravenous glucose load (0.33 g/kg body weight during 3 minutes). Nineteen patients with normal K values were randomized to groups treated either with propranolol in the daily dose of 120 mg (10 patients) or 400 mg acebutolol (9 patients). Twelve patients with low K values were randomized to groups treated with either propranolol (5 patients) or acebutolol (7 patients). The second IVGTT was performed after 7 days of therapy. Glucose, FFA and insulin levels were determined in all blood samples whereas T3 and T4 were determined in samples taken at 0 minute. Plasma T3, T4 and insulin levels were assayed with radioimmunological technique, glucose--with glucose oxidase, and FFA--colorimetrically. Significantly higher plasma FFA levels were found in patients with low K values in comparison with control group. There were no differences in plasma FFA levels in both hyperthyroid patients and normal subjects. Acebutolol but not propranolol normalized K value whereas propranolol (but not acebutolol) significantly decreased acute phase of insulin secretion. Plasma glucose and insulin levels as well as K value were not altered during propranolol acebutolol therapy in patients with normal K value.(ABSTRACT TRUNCATED AT 250 WORDS)