Effects of a week's beta-adrenoceptor blockade with atenolol and metoprolol CR/ZOK on the response to exercise in healthy women aged 50 to 70 years.
12 healthy women with a mean age of 60 years (range 50-70 years) were treated with 50 mg atenolol or 100 mg metoprolol CR/ZOK or placebo for 1 week in a double-blind, randomized, cross-over study. Laboratory measurements of the cardiovascular responses to exercise were made 2-4 hours after and again 24 hours after the last tablet. Blood pressure and heart rate at rest were reduced equally by the two beta-adrenoceptor antagonists. The reductions in blood pressure and heart rate during graded exercise and then during prolonged steady treadmill exercise 3-4 hours after the tablet were greater for atenolol than metoprolol CR/ZOK. The reductions in cardiac output showed a similar pattern. Lactate concentrations and ratings of perceived exertion tended to be highest on metoprolol CR/ZOK, but these differences were inconsistent. We conclude that despite the changes in the cardiovascular system in these 50-70 year-old women, exercise tolerance was not greatly affected by beta-adrenoceptor blockade.
Patrick
J
J
Department of Physiology and Pharmacology, University of Nottingham Medical School, UK.
Bassey
J
J
Morrant
J
J
Macdonald
I
I
D000368:Aged; D001262:Atenolol / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004562:Electrocardiography; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008790:Metoprolol / Q000008:administration & dosage / Q000494:pharmacology*; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects; D011897:Random Allocation; D012129:Respiratory Function Tests
D003692:Delayed-Action Preparations; D001262:Atenolol; D008790:Metoprolol