Impact of Continuous Positive Airway Pressure on the Occurrence of Acute Exacerbations of COPD in Patients With COPD-OSA Overlap Syndrome (CO-OS)

Inclusion Criteria: * 40 years of age or older * Grade of 2 or higher on the modified Medical Research Council scale (which ranges from 0 to 4, with higher grades indicating more severe dyspnea) * A post-bronchodilator forced expiratory volume in 1 second (FEV1) of less than 70% of the predicted value, and a postbronchodilator ratio of FEV1 to forced vital capacity (FVC) of less than 0.70. * Documented history of at least one moderate or severe COPD exacerbation during the previous year * Clinical suspicion of OSA (based on a STOP-bang questionnaire \>3), * Have a telephone or a tablet or accept to use one during the study, * Willing and able to comply with all study procedures, * Subjects covered by or having the rights to medical care assurance. * An apnea-hypopnea index \[AHI\], ≥15 per hour based on a full night polysomnography and no significant central apneas (\<5 central apneas per hour of sleep Exclusion Criteria: * Severe daytime sleepiness (Epworth sleepiness Scale \>14/24 and/or frequent sleepiness while driving or patient escaping a sleep-onset accident within the last 12 months), * Severe unstable cardiovascular disease (heart failure with FEVG≤45%, recurrent cardiac arrhythmia, instable coronary heart disease or stroke), * Patient on long-term oxygen therapy or non-invasive ventilation * Previously documented severe hypercapnia (PaCO2 ≥ 50mm Hg) * Previously diagnosed and treated OSA * Any rehabilitation program or any lung volume reduction procedure planned in the oncoming year * Pregnancy, breastfeeding * Bad understanding of the French language, * Other protected person according to articles L1121.7 and L1121.8 of the French Public Health Act