Reduced ambulatory heart rate response to physical work and complaints of fatigue among hypertensive males treated with beta-blockers.

Treatment with beta-blockers affects oxygen metabolism and lipolysis during physical exertion. Together with possible central nervous system effects, this may impair the work capacity of treated hypertensive subjects. In a study of 1619 male employees, aged 45-64 years, mean resting and ambulatory heart rate (HR) and complaints of fatigue were compared between hypertensive workers treated with beta-blockers and untreated hypertensives and normotensives under low and high workload conditions. Treated hypertensives had lower mean resting HRs compared with normotensives and untreated hypertensives. Their change from resting to ambulatory HR during low and high workload was also lower than normotensives and untreated hypertensives, and they had higher fatigue scores than their untreated counterparts at both workload levels. The highest fatigue score was reported by treated subjects under high workload. These findings demonstrate a reduced HR response to physical work accompanied by more symptoms of fatigue during treatment with beta-blockers. When hypertensives are engaged in physically demanding work, other classes of antihypertensive therapy should be considered.