Severity of oxygen desaturation in OSA–COPD overlap syndrome compared to OSA alone: an observational cohort study

Abstract

Abstract Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea (OSA) syndrome (OSAS) are both common conditions. Their comorbid association – overlap syndrome (OVS) – can result in clinically important nocturnal oxygen desaturation. We sought to compare demographic and anthropometric characteristics, associated comorbidities and oxygen saturation in patients with OVS versus OSA alone. Methods We included consecutive patients diagnosed with OSA in our sleep laboratory. Overnight sleep studies were performed, and data regarding demographic and anthropometric characteristics, prevalence of comorbidities and somnographic parameters were compared for patients with OVS versus OSA alone. A P value of <0.05 was considered significant. Results A total of 2173 OSA patients were assessed, of whom 381 (17.5%) had OVS. Significant differences were found between the OVS and OSA groups regarding all evaluated demographic and anthropometric characteristics, prevalence of comorbidities and somnographic parameters. Conclusions OVS patients were older, were predominantly male, had a higher prevalence of common cardiovascular and metabolic comorbidities, and had worse apnoea–hypopnoea index (AHI) and oxygen saturation parameters.