title: Cardiovascular risk in patients with sleep apnoea with or without continuous positive airway pressure therapy: follow-up of 4.5 million Danish adults.
abstract: BACKGROUND
  The prognostic significance of age and continuous positive airway pressure (CPAP) therapy on cardiovascular disease in patients with sleep apnoea has not been assessed previously.
  
  
  METHODS
  Using nationwide databases, the entire Danish population was followed from 2000 until 2011. First-time sleep apnoea diagnoses and use of CPAP therapy were determined. Incidence rate ratios (IRRs) of ischaemic stroke and myocardial infarction (MI) were analysed using Poisson regression models.
  
  
  RESULTS
  Amongst 4.5 million individuals included in the study, 33 274 developed sleep apnoea (mean age 53, 79% men) of whom 44% received persistent CPAP therapy. Median time to initiation of CPAP therapy was 88 days (interquartile range 34-346). Patients with sleep apnoea had more comorbidities compared to the general population. Crude rates of MI and ischaemic stroke were increased for sleep apnoea patients (5.4 and 3.6 events per 1000 person-years compared to 4.0 and 3.0 in the general population, respectively). Relative to the general population, risk of MI [IRR 1.71, 95% confidence interval (CI) 1.57-1.86] and ischaemic stroke (IRR 1.50, 95% CI 1.35-1.66) was significantly increased in patients with sleep apnoea, in particular in patients younger than 50 years (IRR 2.12, 95% CI 1.64-2.74 and IRR 2.34, 95% CI 1.77-3.10, respectively). Subsequent CPAP therapy was not associated with altered prognosis.
  
  
  CONCLUSIONS
  Sleep apnoea is associated with increased risk of ischaemic stroke and MI, particularly in patients younger than 50 years of age. CPAP therapy was not associated with a reduced rate of stroke or MI.
authors.affiliation: Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Lamberts
authors.forename: O W
authors.initials: OW
authors.lastname: Nielsen
authors.forename: G Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: M H
authors.initials: MH
authors.lastname: Ruwald
authors.forename: C B
authors.initials: CB
authors.lastname: Christiansen
authors.forename: S L
authors.initials: SL
authors.lastname: Kristensen
authors.forename: C
authors.initials: C
authors.lastname: Torp-Pedersen
authors.forename: M L
authors.initials: ML
authors.lastname: Hansen
authors.forename: G H
authors.initials: GH
authors.lastname: Gislason
mesh_terms: D000367:Age Factors; D002545:Brain Ischemia / Q000150:complications / Q000453:epidemiology*; D015897:Comorbidity; D045422:Continuous Positive Airway Pressure; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000453:epidemiology*; D016012:Poisson Distribution; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000150:complications / Q000453:epidemiology* / Q000628:therapy*; D020521:Stroke / Q000150:complications / Q000453:epidemiology*
keywords: contionus positive airway pressure; ischemic stroke; myocardial infarction; sleep apnea; thromboembolism