title: Excessive daytime sleepiness in asthma: What are the risk factors?
abstract: Previous studies have found that excessive daytime sleepiness (EDS) is a more common problem in asthmatic subjects than in the general population. The aim of this study was to investigate whether the prevalence of EDS is increased in asthmatic subjects and, if so, to analyse the occurrence of potential risk factors for EDS in asthmatics.
  
  
  
  Cross-sectional epidemiological study. In 2008, a postal questionnaire was sent out to a random sample of 45,000 individuals aged 16-75 years in four Swedish cities.
  
  
  
  Of the 25,160 persons who participated, 7.3% were defined as having asthma. The prevalence of EDS was significantly higher in asthmatic subjects (42.1% vs. 28.5%, p < 0.001) compared with non-asthmatic subjects. Asthma was an independent risk factor for EDS (adjusted OR 1.29) and the risk of having EDS increased with asthma severity. Risk factors for EDS in subjects with asthma included insomnia (OR, 3.87; 95% CI, 3.10-4.84); chronic rhinosinusitis (OR, 2.00; 95% CI, 1.53-2.62); current smoking (OR, 1.60; 95% CI, 1.15-2.22) and obesity (OR, 1.53; 95% CI, 1.09-2.13).
  
  
  
  EDS is a common problem among subjects with asthma. Asthma is an independent risk factor for having EDS. Furthermore, subjects with asthma often have other risk factors for EDS, many of them potentially modifiable.
authors.affiliation: a Department of Medical Sciences : Respiratory, Allergy and Sleep Research, Uppsala University , Uppsala , Sweden.
authors.forename: Sandra Andersson
authors.initials: SA
authors.lastname: Kallin
authors.affiliation: a Department of Medical Sciences : Respiratory, Allergy and Sleep Research, Uppsala University , Uppsala , Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Lindberg
authors.affiliation: b Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine , Umeå University , Umeå , Sweden.
authors.forename: Johan Nilsson
authors.initials: JN
authors.lastname: Sommar
authors.affiliation: c Department of Internal Medicine and Clinical Nutrition , Krefting Research Centre, Sahlgrenska Academy, University of Gothenburg , Göteborg , Sweden.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Bossios
authors.affiliation: c Department of Internal Medicine and Clinical Nutrition , Krefting Research Centre, Sahlgrenska Academy, University of Gothenburg , Göteborg , Sweden.
authors.forename: Linda
authors.initials: L
authors.lastname: Ekerljung
authors.affiliation: d Department of Medical Sciences: Clinical Physiology , Uppsala University , Uppsala , Sweden.
authors.forename: Andrei
authors.initials: A
authors.lastname: Malinovschi
authors.affiliation: e The Centre for Allergy Research, Karolinska Institutet , Stockholm , Sweden.|f The Institute of Environmental Medicine, Karolinska Institutet , Stockholm , Sweden.
authors.forename: Roelinde
authors.initials: R
authors.lastname: Middelveld
authors.affiliation: a Department of Medical Sciences : Respiratory, Allergy and Sleep Research, Uppsala University , Uppsala , Sweden.
authors.forename: Christer
authors.initials: C
authors.lastname: Janson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000150:complications* / Q000175:diagnosis; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000453:epidemiology* / Q000209:etiology; D000077260:Sleepiness; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
keywords: Asthma severity; chronic rhinosinusitis; insomnia; physical activity; rhinitis; smoking