The overlaps of asthma or COPD with OSA: A focused review

Asthma, chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea (OSA) are the most common respiratory disorders worldwide. Given demographic and environmental changes, prevalence for each is likely to increase. Although exact numbers are not known, based on chance alone, many people will be affected by both lower airways obstruction and concomitant upper airway obstruction during sleep. Some recent studies suggest that there is a reciprocal interaction, with chronic lung disease predisposing to OSA, and OSA worsening control and outcomes from chronic lung disease. Thus, the combination of wake and sleep respiratory disorders can create an overlap syndrome with unique pathophysiological, diagnostic and therapeutic concerns. Although much work needs to be done, given the above, Respirologists, Sleep Medicine and Primary Care providers must be vigilant for overlap syndromes. Accurate diagnosis of, for example, OSA as a cause of nocturnal symptoms in a patient with asthma is likely to limit further ineffective titration of medications for asthma. Moreover, prompt treatment of OSA in the overlap syndromes will not only offer symptomatic benefit of OSA, but also improve symptoms and healthcare resource utilization attributable to obstructive lung disease, and in COPD, it may reduce mortality.