Valentini M et al. – Exercise performance is better preserved with nebivolol than with carvedilol under acute exposure to high altitude (HA) hypoxia in healthy subjects.Methods
- 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).