title: Obstructive sleep apnea is a risk factor for death in patients with stroke: a 10-year follow-up.
abstract: BACKGROUND
  Sleep apnea occurs frequently among patients with stroke, but it is still unknown whether a diagnosis of sleep apnea is an independent risk factor for mortality. We aimed to investigate whether obstructive or central sleep apnea was related to reduced long-term survival among patients with stroke.
  
  
  METHODS
  Of 151 patients admitted for in-hospital stroke rehabilitation in the catchment area of Umeå from April 1, 1995, to May 1, 1997, 132 underwent overnight sleep apnea recordings at a mean (SD) of 23 (8) days after the onset of stroke. All patients were followed up prospectively for a mean (SD) of 10.0 (0.6) years, with death as the primary outcome; no one was lost to follow-up. Obstructive sleep apnea was defined when the obstructive apnea-hypopnea index was 15 or greater, and central sleep apnea was defined when the central apnea-hypopnea index was 15 or greater. Patients with obstructive and central apnea-hypopnea indexes of less than 15 served as control subjects.
  
  
  RESULTS
  Of 132 enrolled patients, 116 had died at follow-up. The risk of death was higher among the 23 patients with obstructive sleep apnea than controls (adjusted hazard ratio, 1.76; 95% confidence interval, 1.05-2.95; P = .03), independent of age, sex, body mass index, smoking, hypertension, diabetes mellitus, atrial fibrillation, Mini-Mental State Examination score, and Barthel index of activities of daily living. There was no difference in mortality between the 28 patients with central sleep apnea and controls (adjusted hazard ratio, 1.07; 95% confidence interval, 0.65-1.76; P = .80).
  
  
  CONCLUSIONS
  Patients with stroke and obstructive sleep apnea have an increased risk of early death. Central sleep apnea was not related to early death among the present patients.
authors.affiliation: Department of Respiratory Medicine, Umeå University Hospital, SE-901 85 Umeå, Sweden.
authors.forename: Carin
authors.initials: C
authors.lastname: Sahlin
authors.forename: Olov
authors.initials: O
authors.lastname: Sandberg
authors.forename: Yngve
authors.initials: Y
authors.lastname: Gustafson
authors.forename: Gösta
authors.initials: G
authors.lastname: Bucht
authors.forename: Bo
authors.initials: B
authors.lastname: Carlberg
authors.forename: Hans
authors.initials: H
authors.lastname: Stenlund
authors.forename: Karl A
authors.initials: KA
authors.lastname: Franklin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000209:etiology / Q000401:mortality*; D020521:Stroke / Q000150:complications / Q000401:mortality*; D016019:Survival Analysis