Blood pressure variability and plasma catecholamines in man effect of propranolol therapy

Blood pressure variability and plasma catecholamine concentrations were monitored during a 60-min period in the supine position and 15-min period in the standing position in 13 normotensive and 20 age-matched hypertensive subjects. The standard deviation of 30 and 7 blood pressure measurements in the supine and standing positions, respectively, was taken as the index of pressure variability. In the hypertensive patients measurements were repeated while on propranolol therapy for 6 to 8 weeks. Blood pressure variability was correlated to the levels of blood pressure and was significantly greater in the hypertensive than the normotensive group. Plasma epinephrine concentration was correlated with blood pressure variability in both positions in the normotensive and hypertensive subjects, whereas plasma norepinephrine concentration was correlated with variability of blood pressure in the hypertensive group only. Quiet standing was associated with an increase in both blood pressure variability and plasma catecholamine concentration. The administration of propranolol at a daily dosage of 160 to 320 mg slightly decreased blood pressure and did not affect variability significantly, although both epinephrine and norepinephrine increased significantly during propranolol therapy.