title: Associations between obstructive lung disease and symptoms of obstructive sleep apnoea in a general population.
abstract: OBJECTIVE
  To examine the prevalence of self-reported symptoms of obstructive sleep apnoea (OSA) in relation to asthma, respiratory symptoms and pulmonary function. A secondary objective was to determine how sex impacted these relationships.
  
  
  METHODS
  A random sample of all adults aged 47-48 and 71-73 years living in Bergen, Norway, were invited. Participants (3506, 69%) underwent spirometry testing and completed a questionnaire on sleep, respiratory symptoms and past medical history. OSA was defined by positive answers to questions on snoring, breathing cessations and daytime sleepiness. Current asthma was defined by ever having received a physician's diagnosis of asthma and current use of anti-asthma medication. Logistic regression analyses, including interaction analyses between sex and the different explanatory variables, were used to examine associations between OSA and current asthma, pre- and post-bronchodilator pulmonary function tests, smoking habits and respiratory symptoms. All models were adjusted for age, sex, waist-hip ratio and smoking.
  
  
  RESULTS
  OSA was more prevalent in the middle-aged compared to the elderly (6.2% vs 3.6%), and in subjects reporting respiratory symptoms. 4.8% had OSA and 6.1% had current asthma. Current asthma and the lowest quartile of post-bronchodilator FVC were significantly associated with OSA with ORs of 2.5 (1.5, 4.2) and 1.7 (1.1, 2.7), respectively. In interaction analyses, women with post-bronchodilator FEV1/FVC < 0.7 had an increased risk of OSA [OR of 4.1 (1.7, 9.7)] compared to women with a FEV1/FVC ≥ 0.7.
  
  
  CONCLUSIONS
  Current asthma was associated with increased risk of OSA. Women with chronic airflow limitation, but not men, had increased risk of OSA.
authors.affiliation: Center for Sleep Medicine, Haukeland University Hospital, Bergen, Norway.|Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Trygve Müller
authors.initials: TM
authors.lastname: Jonassen
authors.affiliation: Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Science, University of Bergen, Bergen, Norway.
authors.forename: Tomas Mikal
authors.initials: TM
authors.lastname: Eagan
authors.affiliation: Center for Sleep Medicine, Haukeland University Hospital, Bergen, Norway.|Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway.|Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: Bjørn
authors.initials: B
authors.lastname: Bjorvatn
authors.affiliation: Center for Sleep Medicine, Haukeland University Hospital, Bergen, Norway.|Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Science, University of Bergen, Bergen, Norway.|Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway.
authors.forename: Sverre
authors.initials: S
authors.lastname: Lehmann
mesh_terms: D017677:Age Distribution; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000453:epidemiology; D012189:Retrospective Studies; D017678:Sex Distribution; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors
keywords: COPD; asthma; epidemiology; gender differences; obstructive sleep apnoea