Propranolol or hydrochlorothiazide alone for the initial treatment of hypertension. IV. Effect on plasma glucose and glucose tolerance. Veterans Administration Cooperative Study Group on Antihypertensive Agents.

To evaluate the short-term and long-term effectiveness of propranolol and hydrochlorothiazide monotherapy for hypertension, 683 hypertensive men were randomized to treatment with either propranolol or hydrochlorothiazide. Both drugs increased the average fasting plasma glucose level by approximately 5 mg/dl after 10 weeks (p less than 0.001) and 1 year (p less than 0.001) of treatment, but the elevation persisted only in the propranolol-treated group 1 month after discontinuing the year-long treatment (p less than 0.01). A subset of 191 patients had 2-hour glucose tolerance tests. Hydrochlorothiazide increased the average 2-hour oral glucose tolerance test result by 18.0 mg/dl after 10 weeks (p less than 0.001), an increase significantly higher than that induced by propranolol (p less than 0.012). After 1 year of treatment, however, propranolol also increased the average 2-hour oral glucose tolerance test result (p less than 0.05) and there was no significant difference between drugs. The hyperglycemic effects were dose-related, which suggests that both drugs should be administered at their lowest effective dosage. The clinical importance of the persistent fasting plasma glucose elevation in propranolol-treated patients 1 month after discontinuing treatment is unknown.