title: Relationship between habitual sleep duration, obesity and depressive symptoms in patients with sleep apnoea.
abstract: OBJECTIVE
  Short sleep duration has been linked with obesity in general population, but this issue has not been addressed in patients with obstructive sleep apnoea syndrome (OSAS) separately. Depressive symptoms are frequent in OSAS and may affect sleep and energy balance. Our purpose was to assess the association of habitual sleep duration, psychological distress, depressive symptoms, and excessive daytime sleepiness with measures of obesity in patients with OSAS.
  
  
  METHODS
  210 middle aged consecutive patients (111 men and 99 women) referred for evaluation of suspected OSAS were divided into subgroups based on apnoea-hypopnoea index (AHI) and treatment suggested by a sleep physician.
  
  
  RESULTS
  OSAS (AHI>5/h plus symptoms) was diagnosed in 75.7% of the patients. Their sleep duration correlated negatively with psychological distress (r=-0.22, p=0.043) and depressive symptoms (r=-0.27, p=0.013) in men. No association was found between self-reported habitual sleep duration and measures of obesity or subjective sleepiness. In patients considered for CPAP therapy, sleep duration associated inversely with depressive symptoms both in men (r=-0.28, p=0.024) and women (r=-0.33, p=0.037). After adjusting for age and Epworth Sleepiness Score, the results remained essentially similar.
  
  
  CONCLUSIONS
  Our results suggest that self-reported habitual sleep duration does not associate with obesity in patients with OSAS. Shorter habitual sleep duration seems to associate with higher scores of depressive symptoms and psychological distress.
authors.affiliation: Sleep Research Unit, Department of Physiology, University of Turku, Turku, Finland.
authors.forename: Elena
authors.initials: E
authors.lastname: Gylen
authors.affiliation: Sleep Research Unit, Department of Physiology, University of Turku, Turku, Finland; Division of Medicine, Department of Pulmonary Diseases, Turku University Hospital, Turku, Finland.
authors.forename: Ulla
authors.initials: U
authors.lastname: Anttalainen
authors.affiliation: Sleep Research Unit, Department of Physiology, University of Turku, Turku, Finland; Division of Medicine, Department of Pulmonary Diseases, Turku University Hospital, Turku, Finland. Electronic address: tasaare@utu.fi.
authors.forename: Tarja
authors.initials: T
authors.lastname: Saaresranta
mesh_terms: D000328:Adult; D003863:Depression / Q000209:etiology*; D006970:Disorders of Excessive Somnolence / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D057566:Self Report; D012737:Sex Factors; D012890:Sleep; D012891:Sleep Apnea Syndromes / Q000150:complications; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000628:therapy; D012894:Sleep Stages; D013315:Stress, Psychological / Q000209:etiology*
keywords: Depression; Gender; Obesity; Self-reported sleep duration; Sleep apnoea