Effects of beta-blockade on exercise performance at high altitude: a randomized, placebo-controlled trial comparing the efficacy of nebivolol versus carvedilol in healthy subjects
Cardiovascular Therapeutics, 05/02/2012Valentini M et al.
Exercise performance is better preserved with nebivolol than with carvedilol under acute exposure to high altitude (HA) hypoxia in healthy subjects.
In this double–blind, placebo–controlled trial.
27 healthy untrained sea–level (SL) residents (15 males, age 38.3 ± 12.8 years) were randomized to placebo (n = 9), carvedilol 25 mg b.i.d. (n = 9), or nebivolol 5 mg o.d. (n = 9).
Primary endpoints were measures of exercise performance evaluated by cardiopulmonary exercise testing at sea level without treatment, and after at least 3 weeks of treatment, both at SL and shortly after arrival at HA (4559 m).
HA hypoxia significantly decreased resting and peak oxygen saturation, peak workload, VO2, and heart rate (HR) (P < 0.01).
Changes from SL (no treatment) differed among treatments: (1) peak VO2 was better preserved with nebivolol (–22.5%) than with carvedilol (–37.6%) (P < 0.01); (2) peak HR decreased with carvedilol (–43.9 ± 11.9 beats/min) more than with nebivolol (–24.8 ± 13.6 beats/min) (P < 0.05); (3) peak minute ventilation (VE) decreased with carvedilol (–9.3%) and increased with nebivolol (+15.2%) (P= 0.053).
Only peak VE changes independently predicted changes in peak VO2 at multivariate analysis (R= 0.62, P < 0.01).
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