Correlation between chronic obstructive pulmonary disease and obstructive sleep apnea syndrome in a general population in Iran

Background: the aim of this study was to evaluate epidemiological relationship between chronic obstructive pulmonary disease and sleep apnea syndrome in a sample of persian population. methods: as a part of a population-based cross-sectional study, 3900 randomly selected individuals aged 15 years or older were invited to take part in the survey; 3770 individuals (96.6%) agreed to fill out the respiratory and sleep questionnaire. those subjects suspected to have either chronic obstructive pulmonary disease and/or obstructive sleep apnea underwent spirometry and polysomnography test if indicated. spirometric measurements were performed on 420 invited responders. polysomnography measurements were performed on 25 of the responders. results: prevalence rates for sleep apnea, chronic obstructive pulmonary disease and current asthma were 4.98%, 5.7% and 3.1%, respectively. logistic regression showed independent associations between sleep apnea and chronic obstructive pulmonary disease. there was no significant independent association between sleep apnea symptoms and current asthma and wheeze ever. conclusions: these observations indicated relationship between chronic obstructive pulmonary disease and obstructive sleep apnea. these observations indicated the necessity of further studies to explain the possible common patho- genic mechanisms involved in two disease entities.