Effect of beta 1-selective and nonselective beta blockade on blood pressure relative to physical performance in men with systemic hypertension

Abstract

Eleven physically active men with systemic hypertension were studied after 5 weeks of treatment with placebo, atenolol or propranolol. A double-blind, crossover randomized design was used. Blood pressure (BP), heart rate (HR), physical performance capacity, rate of perceived exertion and blood lactate concentrations were measured during rest, exercise to exhaustion and postexercise, at 8 and 24 hours after intake of the last dose. Blood pressure at rest and during exercise was similarly decreased with both drugs (8 and 24 hours), and there was no difference between 8 and 24 hours with any of the treatments. Heart rate (8 hours) was decreased similarly by both drugs, but after 24 hours, HR at increased workloads (above 120 watts) was higher with atenolol compared with propranolol. Maximal HR was lower with propranolol than atenolol at both 8 and 24 hours. Maximal exercise loads (8 and 24 hours) were 231 and 232 watts with placebo, 211 and 212 with propranolol and 228 and 227 with atenolol. That is, maximal workload was decreased with propranolol compared with placebo and atenolol at both 8 and 24 hours. No difference was found between placebo and atenolol at either 8 or 24 hours. The rate of perceived exertion values were higher with propranolol than atenolol. Blood lactate concentrations did not differ according to treatments. The results indicate that atenolol, when given in a dose that decreases resting and exercise BP to the same extent as propranolol, limits physical performance less than propranolol.