Impact of Positive Airway Pressure Therapy on Clinical Outcomes in Older Veterans With Chronic Obstructive Pulmonary Disease and Comorbid Obstructive Sleep Apnea (Overlap Syndrome)

Who May Qualify: - OSA with moderate-to-severe disease, AHI 20 per hour by in-lab polysomnography with concomitant moderate-severe COPD based on pulmonary function tests (PFTS) and with past significant history (\>10 pack-years) of smoking - Male or female gender - Age greater than or equal to 60 years - Stable treatment regimen for COPD Who Should NOT Join This Trial: - Current or prior treatment with PAP or oral appliance - Central sleep apnea defined as central apnea index \>5 per hour and comprising 50% of AHI - Known primary neuromuscular diseases - Disorders that may impact cognitive function including: - neurodegenerative disorders - traumatic brain injury - untreated PTSD and/or history of learning disability - Medicines that may cause or alter sleepiness: sedative hypnotics, or stimulants as these may alter the results - Patient is actively suicidal due to depression, unstable mental health condition - Epworth sleepiness score \>16 (severe sleepiness) or a near-miss or prior automobile accident due to sleepiness within the past 12 months - Narcolepsy is the primary sleep disorder, with requirement of stimulant medications - Employed as a commercial driver or operating heavy machinery - On long-term oxygen therapy prior to start of study, more than 12 hr/day - Patients is unable to use either a nasal or face mask (e.g., facial trauma, claustrophobia) - Consumption of \>3 alcoholic beverages per day or current use of some illicit drugs, as these may contribute to cognitive deficits - Patients who cannot give willing to sign a consent form - Patients receiving hospice care - Pregnant women due to unknown risks Always talk to your doctor about whether this trial is right for you.