The Overlap Syndrome of Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease: A Systematic Review

Abstract

Review question / Objective: To provide the essential findings in the field of overlap syndrome of chronic obstructive pulmonary disease and obstructive sleep apnea, including prevalence, possible predictors, association with clinical outcomes, and severity compared to both chronic obstructive pulmonary disease and obstructive sleep apnea patients. Condition being studied: OSA is characterized by complete cessation (apnea) or significant decrease (hy-popnea) in airflow during sleep and recurrent episodes of upper airway collapse cause it during sleep leading to nocturnal oxyhemoglobin desaturations and arousals from rest. The recurrent arousals which occur in OSA lead to neurocognitive consequences, daytime sleepiness, and reduced quality of life. Because of apneas and hypopneas, patients are experiencing hypoxemia and hypercapnia, which result in increasing levels of catecholamine, oxidative stress, and low-grade inflammation that lead to the appearance of cardio-metabolic consequences of OSA. COPD is a chronic inflammatory lung disease defined by persistent, usually pro-gressive AFL (airflow limitation). Changes in lung mechanics lead to the main clini-cal manifestations of dyspnea, cough, and chronic expectoration. Furthermore, patients with COPD often suffer from anxiety and depression also, the risk of OSA and insomnia is higher than those hospitalized for other reasons. Although COPD is twice as rare as asthma but is the cause of death eight times more often.