title: Obstructive sleep apnea in patients with abdominal aortic aneurysms: highly prevalent and associated with aneurysm expansion.
abstract: BACKGROUND
  Abdominal aortic aneurysms (AAA) are associated with life-threatening complications. The likelihood that an AAA will rupture is influenced by the aneurysm diameter and its expansion rate; reasons for rapid expansion are largely unknown.
  
  
  OBJECTIVE
  To determine the prevalence of obstructive sleep apnea (OSA) in patients with AAA, and investigate a possible association between OSA and rate of AAA expansion.
  
  
  METHODS
  A total of 127 patients (11 females), included in an AAA surveillance program, agreed to participate and underwent a sleep study. Annual AAA expansion was determined retrospectively from available ultrasound measurements. OSA was characterized using both oxygen desaturation index (ODI) and apnea-hypopnea index (AHI). Univariate and multivariate analysis was performed to assess the effect of OSA severity on AAA expansion.
  
  
  RESULTS
  Mean age was 67.9 (SD, 6) years. Median interval between the first and last AAA measurements was 18 (range, 2-113) months. An ODI or AHI of greater than 10 was found in 40.5% and 41.5% of the patients, respectively. Patients with an ODI greater than 30 (n = 12) had a significantly faster median yearly AAA expansion rate (2.9; quartiles 2/5.7 mm/y) than patients with an ODI 0-5 (n = 47; 1.2; quartiles 0/3.1 mm/y) or 6-15 (n = 43; 1.3; quartiles 0/2.7 mm/y) (P < 0.05). In multivariate regression analysis, controlling for cardiovascular risk factors and medications, ODI greater than 30 remained an independent risk factor for AAA expansion.
  
  
  CONCLUSIONS
  In patients with AAA, OSA is highly prevalent. Severe OSA may be a causal factor for faster AAA expansion, but this needs to be proved in a randomized controlled intervention trial.
authors.affiliation: Oxford Centre for Respiratory Medicine, Churchill Hospital, United Kingdom. Rebecca.Mason@orh.nhs.uk
authors.forename: Rebecca H
authors.initials: RH
authors.lastname: Mason
authors.forename: Gion
authors.initials: G
authors.lastname: Ruegg
authors.forename: Jeremy
authors.initials: J
authors.lastname: Perkins
authors.forename: Maxine
authors.initials: M
authors.lastname: Hardinge
authors.forename: Beatrice
authors.initials: B
authors.lastname: Amann-Vesti
authors.forename: Oliver
authors.initials: O
authors.lastname: Senn
authors.forename: John R
authors.initials: JR
authors.lastname: Stradling
authors.forename: Malcolm
authors.initials: M
authors.lastname: Kohler
mesh_terms: D000328:Adult; D000368:Aged; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000453:epidemiology*; D001837:Body Weights and Measures / Q000379:methods; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology*; D013557:Switzerland / Q000453:epidemiology; D014463:Ultrasonography; D006113:United Kingdom / Q000453:epidemiology