Effects of Positive Airway Pressure Therapy on Cognitive Function in Patients with Obstructive Sleep Apnea: A Prospective Observational Study Protocol

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is increasingly recognized as a contributor to cognitive decline and a potential risk factor for neurodegeneration. Previous studies have also identified various associated comorbidities such as vascular dysfunction, metabolic alterations, and neuroinflammatory changes. Positive airway pressure (PAP) therapy has been associated with cognitive improvement in some studies, but its long-term effects on cognitive function remain uncertain. This study employs a prospective, observational, longitudinal cohort design to examine longitudinal associations between disease severity, PAP therapy and cognition. Additionally, we aim to examine the relationships between cognitive dysfunction, brain structure and associated OSA-related risk factors. A total of 100 eligible participants with mild to severe OSA will be recruited. All participants will undergo comprehensive assessments at baseline and after 12 months, including neurological, pulmonary, and ear, nose and throat clinical examinations, polysomnography, neuropsychological testing, brain magnetic resonance imaging with volumetry, anthropometric measurements, blood and saliva sampling for the assessment of the selected laboratory parameters, gut microbiome analysis, and evaluation of endothelial function and baroreflex sensitivity. This study may improve understanding of how PAP therapy and OSA-related pathophysiological processes influence cognitive outcomes.