man rock_climbingUse of a combination therapy in individuals with obstructive sleep apnea (OSA) traveling to higher altitudes resulted in improvement in symptoms and better control of sleep apnea, according to a study conducted by Tsogyal D. Latshang, MD, of the University of Zurich, Switzerland.

Researchers conducted the study to evaluate whether taking of the drug acetazolamide (a respiratory stimulant used to treat acute mountain sickness and high-altitude periodic breathing) combined with auto-adjusted continuous positive airway pressure would provide better oxygenation and control of sleep-related breathing disturbances than autoCPAP alone in patients with OSA spending a few days at moderate altitude.

The randomized trial included 51 patients with OSA living below an altitude of 800 meters (2,625 feet) and receiving CPAP therapy who underwent studies at a university hospital at 490 meters (1,608 feet) and resorts in Swiss mountain villages at 1,630 meters (5,348 feet) and 2,590 meters (8,497 feet) in the summer of 2009. Patients were studied during two stays of 3 days each in the mountain villages. At altitude, patients took either acetazolamide (750 mg/d) or placebo in addition to autoCPAP.

Researchers found that at 1,630 meters and 2,590 meters, combined acetazolamide and autoCPAP treatment was associated with higher oxygen saturation and a lower apnea/hypopnea index (AHI) compared with placebo and autoCPAP.

“Our study provides important information for patients with OSA planning a stay at altitude because they can continue using their CPAP in autoadjusting mode during altitude travel and enhance this treatment with acetazolamide if they want to spend less time awake at night, to achieve a higher arterial oxygen saturation and an optimal control of sleep apnea,” according to the study authors.

The study appears in the December 12 issue of JAMA.