Effects of short-term PAP treatment on endurance exercise performance in obstructive sleep apnea patients

Objective: To measure the effects of 4 weeks of nasal positive airway pressure therapy (PAP) on exercise performance in obstructive sleep apnea patients (OSA). Background: Little published research is available which describes the effects of OSA on exercise tolerance or upon the potential of exercise testing to evaluate the outcomes of PAP therapy. Methods: Exercise testing was performed on an electronic cycle ergometer with continuous ramping to allow collection of numerous data points for each subject, up to a vigorous terminal intensity. Linear regression established each subject's pre-treatment scores for the dependent variables at 60% of estimated peak power ( W 60%). Responses at the pre-treatment W 60% test were used to quantify and compare to responses at the same power output after treatment. Results: OSA by nocturnal polysomnography was moderately severe in this group; the respiratory distress index was 48±22 (mean±SD; n=9). Exercise heart rates after PAP therapy averaged 10.2 bt/min less at W 60% ( P