Comparison of peak oxygen consumption in patients with idiopathic hypertension treated with beta-blockers and other antihypertensives

ObjectiveTo investigate whether the use of beta-blockers (β-blockers) in patients with idiopathic hypertension compromises exercise performance.Materials and MethodsRetrospectively, patients with well-controlled hypertension, who had received cardiopulmonary exercise testing (CPET) and pulmonary function testing, were consecutively enrolled. Their medical histories were reviewed. They were grouped into those receiving β-blockers and those receiving other antihypertensives. The heart rate (HR), blood pressure, oxygen consumption (V˙O2), oxygen pulse, ventilatory anaerobic threshold, and respiratory exchange ratio were measured during CPET. The forced vital capacity and forced expiratory volume in 1 second were also collected from pulmonary function testing. Peak values of the CPET indices were compared between the two groups for each index separately by the Mann-Whitney U test. A p value less than 0.05 was considered statistically significant.ResultsNo significant differences were observed in basic characteristics, such as age (59 ± 9 years vs. 62 ± 9 years), and peak oxygen pulse (11 ± 3 vs. 11 ± 4), between the groups receiving β-blockers and other antihypertensives, respectively. Their resting systolic pressures were well controlled under antihypertensive medication (114 ± 13 mmHg vs. 118 ± 19 mmHg). A significantly lower maximal HR and maximal systolic blood pressure during peak exercise was observed in the β-blocker group compared with those in the other group (129.5 ± 17.0 beats/min vs. 146.1 ± 18.3 beats/min, p = 0.008, and 159.0 ± 22.2 mmHg vs. 172.6 ± 29.8 mmHg, p = 0.028, respectively). The exercise capacity of the β-blocker group was reduced, as shown by a lower measured peak V˙O2/predicted peak V˙O2 (V˙O2%) (84.2% ± 9.6% vs. 96.2% ± 14.6%, p = 0.003) and a higher exercise heart rate reserve percentage (19.8% ± 10.3% vs. 7.8 ± 10.3%, p = 0.001).ConclusionsThe maximal HR, systolic blood pressure during peak exercise, and V˙O2% were lower, whereas the exercise heart rate reserve percentage was greater in patients treated with β-blockers than in those taking other antihypertensives.