Metoprolol combined with moderate-intensity aerobic exercise improves skeletal muscle functional sympathol-ysis and the exercise capacity of mildly hypertensive men / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the effect of metoprolol and metoprolol combined with moderate inten-sity aerobic exercise on the sympathetic vasoconstriction response of skeletal muscle, functional sympatholysis and the exercise capacity of hypertensive men. Methods Thirty men with mild ( stage 1) essential hypertension were divi-ded into a drug group and an observation group. The drug group received only metoprolol while the observation group took metoprolol and performed aerobic exercise (intensity 50-70％ of VO2max, 30-45 min/time, 3-5 times/week) for 12 weeks. Before and after the experiment, the subjects' maximum oxygen uptake (VO2max), peak power (PP) as well as a rating of perceived exertion ( RPE) curve during exercise were determined using the graded exercise test. Forearm vascular conductance ( FVC) induced by the cold pressor test was measured using Doppler ultrasound at rest and during a handgrip exercise. Sympathetic vasoconstriction response was manifested by the rate of change in the conductance (％FVC) before and after the cold pressor test. Functional sympatholysis ( the ability of muscle contrac-tions to inhibit sympathetic vasoconstrictor response) was quantified using the difference in the ％FVC values (△％FVC) between the handgrip exercise and at rest. Results After the treatment,％FVC during the handgrip exercise was lower than at rest in the observation group.△％FVC had increased significantly, as had VO2max and PP. The RPE curve during a graded exercise test shifted to the right in the observation group, but there was no significant change in the other observations. In the drug group, PP had decreased significantly and the RPE curve had shifted to the left. Conclusion Metoprolol can better improve functional sympatholysis and enhance exercise capacity when it is com-bined with moderate intensity aerobic exercise. That will alleviate any exercise intolerance in men with mild hyperten-sion caused by taking metoprolol alone.