Lung air trapping lowers respiratory arousal threshold and contributes to sleep apnea pathogenesis in COPD patients with overlap syndrome

Study objectives: Overlap syndrome occurs when obstructive sleep apnea (OSA) and chronic obstructive pulmonary disorder (COPD) coexist in the same patient. Although several studies highlighted the importance of clinical phenotyping in OSA, the trait contribution to OSA pathogenesis in overlap syndrome has not been investigated. With this pilot study, we aimed to measure OSA determinants and their relationship with functional respiratory parameters in a sample of patients with overlap syndrome. In particular, we hypothesize that patients with COPD have in the low arousal threshold a major contributor for the development of OSA. Methods: Ten consecutive non-hypercapnic COPD patients (body mass index