Prevalence and clinical feature of the “overlap syndrome”, obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD), in OSA population

Purpose The association of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA), defined overlap syndrome by Flenley, is frequent. Aims of the present study were to assess the frequency of overlap syndrome in 168 consecutive OSA patients, and to evaluate the functional pulmonary hemodynamic, and polysomnographic consequences of this association by comparing Overlap patients with OSA patients.