This randomized cross-over trial evaluates the hypothesis that patients with chronic obstructive pulmonary disease experience nocturnal hypoxemia, periodic breathing and sleep disturbances when staying at moderate altitude. Sleep studies and clinical evaluations will be performed during 2 days in Zurich (490 m, low altitude baseline) and during 2 days at Davos Clavadel (1650 m), and 2 days at Davos Jakobshorn (2590 m).
The purpose of this study is to evaluate whether nocturnal breathing and sleep of patients with chronic obstructive pulmonary disease (COPD) are disturbed during a stay at moderate altitude.