Long term effects of PAP therapy on patients with obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) (overlap syndrome)

Background: There are data suggesting that overlap syndrome (OS) is associated with significant morbidity and mortality, mainly due to cardiovascular (CVD) consequences. Aims and Objectives: To investigate the effect of positive airway pressure (PAP) treatment on sleepiness, depressive symptoms, hospitalization rate and mortality in patients with OS. Methods: In this prospective study, 196 COPD consecutive patients referred for OSA evaluation underwent polysomnography. Using an AHI≥ 15 for OSA diagnosis resulted in 193 patients with OS. We examined the effect of PAP therapy on hospitalization rate due to COPD exacerbations and mortality after two years of PAP therapy. The patients also completed the Epworth Sleepiness Scale (ESS) and Beck Depression scale (BDS) before and at the end of the follow up period. Results: At 2-year follow-up 156 patients completed the study. Of them 37 (24%) were hospitalized for COPD exacerbations and 4 died (3%) due to CVD. Patients with ≥6 hours PAP showed better survival (0 vs 4, p =0.03), lower hospitalization rates (12 vs 25, p=0.02), improvement in ESS (9 vs 12, p=0.01) and BDI (11 vs 15, p=0.009) score compared to patients with l6 h use. Multiple regression analysis identified female gender (HR 7.0; 95% CI 0.8–58.9; p = 0.04) and lower hours of PAP use (HR 0.55; 95% CI 0.29–1.0; p =0.04) as predictors of mortality. Conclusions: Our data suggest that effective PAP treatment results in a significant improvement in hospitalization rate, symptoms and mortality in patients with OS.