title: Obstructive sleep apnea, obesity, and the risk of incident atrial fibrillation.
abstract: OBJECTIVE
  This study sought to identify whether obesity and obstructive sleep apnea (OSA) independently predict incident atrial fibrillation/flutter (AF).
  
  
  BACKGROUND
  Obesity is a risk factor for AF, and OSA is highly prevalent in obesity. Obstructive sleep apnea is associated with AF, but it is unknown whether OSA predicts new-onset AF independently of obesity.
  
  
  METHODS
  We conducted a retrospective cohort study of 3,542 Olmsted County adults without past or current AF who were referred for an initial diagnostic polysomnogram from 1987 to 2003. New-onset AF was assessed and confirmed by electrocardiography during a mean follow-up of 4.7 years.
  
  
  RESULTS
  Incident AF occurred in 133 subjects (cumulative probability 14%, 95% confidence interval [CI] 9% to 19%). Univariate predictors of AF were age, male gender, hypertension, coronary artery disease, heart failure, smoking, body mass index, OSA (hazard ratio 2.18, 95% CI 1.34 to 3.54) and multiple measures of OSA severity. In subjects <65 years old, independent predictors of incident AF were age, male gender, coronary artery disease, body mass index (per 1 kg/m2, hazard ratio 1.07, 95% CI 1.05 to 1.10), and the decrease in nocturnal oxygen saturation (per 0.5 U log change, hazard ratio 3.29, 95% CI 1.35 to 8.04). Heart failure, but neither obesity nor OSA, predicted incident AF in subjects > or =65 years of age.
  
  
  CONCLUSIONS
  Obesity and the magnitude of nocturnal oxygen desaturation, which is an important pathophysiological consequence of OSA, are independent risk factors for incident AF in individuals <65 years of age.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Apoor S
authors.initials: AS
authors.lastname: Gami
authors.forename: Dave O
authors.initials: DO
authors.lastname: Hodge
authors.forename: Regina M
authors.initials: RM
authors.lastname: Herges
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Olson
authors.forename: Jiri
authors.initials: J
authors.lastname: Nykodym
authors.forename: Tomas
authors.initials: T
authors.lastname: Kara
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications*