Under acute exposure to high altitude hypobaric hypoxia, nebivolol better than carvedilol
FRIDAY, July 13 (HealthDay News) -- Under high altitude (HA) hypoxemia conditions, exercise performance seems to be better preserved with nebivolol than carvedilol, according to a study published in the August issue of Cardiovascular Therapeutics.
Mariaconsuelo Valentini, M.D., from Luca Hospital in Milan, Italy, and colleagues conducted a double-blind, placebo-controlled trial in which 27 healthy untrained, sea-level residents (15 males, age 38.3 ± 12.8 years) were randomized to receive placebo, carvedilol, or nebivolol in a 1:1:1 ratio. The impact of the β-blockers on exercise capacity was compared on acute exposure to HA hypobaric hypoxia.
The researchers found that acute exposure to HA hypoxia correlated with significant decreases in resting and peak oxygen saturation, peak workload, peak oxygen consumption (VO2), and heart rate. Performance changes differed among the groups, with peak VO2 significantly better preserved with nebivolol than with carvedilol (−22.5 versus −37.6 percent); peak heart rate decreased significantly more with carvedilol than with nebivolol (−43.9 ± 11.9 versus −24.8 ± 13.6 beats/minute) and peak minute ventilation decreased with carvedilol but increased with nebivolol (−9.3 versus +15.2 percent; P = 0.053). The only significant independent predictor of changes in peak VO2 in multivariate analysis was peak ventilation changes.
"Exercise performance is better preserved with nebivolol than with carvedilol under acute exposure to HA hypoxia in healthy subjects," the authors write.
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