title: Sleep characteristics of persons with chronic fatigue syndrome and non-fatigued controls: results from a population-based study.
abstract: BACKGROUND
  The etiology and pathophysiology of chronic fatigue syndrome (CFS) remain inchoate. Attempts to elucidate the pathophysiology must consider sleep physiology, as unrefreshing sleep is the most commonly reported of the 8 case-defining symptoms of CFS. Although published studies have consistently reported inefficient sleep and documented a variable occurrence of previously undiagnosed primary sleep disorders, they have not identified characteristic disturbances in sleep architecture or a distinctive pattern of polysomnographic abnormalities associated with CFS.
  
  
  METHODS
  This study recruited CFS cases and non-fatigued controls from a population based study of CFS in Wichita, Kansas. Participants spent two nights in the research unit of a local hospital and underwent overnight polysomnographic and daytime multiple sleep latency testing in order to characterize sleep architecture.
  
  
  RESULTS
  Approximately 18% of persons with CFS and 7% of asymptomatic controls were diagnosed with severe primary sleep disorders and were excluded from further analysis. These rates were not significantly different. Persons with CFS had a significantly higher mean frequency of obstructive apnea per hour (p = .003); however, the difference was not clinically meaningful. Other characteristics of sleep architecture did not differ between persons with CFS and controls.
  
  
  CONCLUSIONS
  Although disordered breathing during sleep may be associated with CFS, this study generally did not provide evidence that altered sleep architecture is a critical factor in CFS. Future studies should further scrutinize the relationship between subjective sleep quality relative to objective polysomnographic measures.
authors.affiliation: Viral Exanthems & Herpesvirus Branch, Division of Viral & Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control & Prevention, Atlanta, GA, USA. wcr1@cdc.gov
authors.forename: William C
authors.initials: WC
authors.lastname: Reeves
authors.forename: Christine
authors.initials: C
authors.lastname: Heim
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Maloney
authors.forename: Laura Solomon
authors.initials: LS
authors.lastname: Youngblood
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Unger
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Decker
authors.forename: James F
authors.initials: JF
authors.lastname: Jones
authors.forename: David B
authors.initials: DB
authors.lastname: Rye
mesh_terms: D016022:Case-Control Studies; D018672:Community Health Planning; D004569:Electroencephalography / Q000379:methods; D004576:Electromyography / Q000379:methods; D015673:Fatigue Syndrome, Chronic / Q000145:classification / Q000453:epidemiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000503:physiopathology; D017286:Polysomnography / Q000379:methods; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012890:Sleep / Q000502:physiology*; D012891:Sleep Apnea Syndromes / Q000503:physiopathology