title: Patients with obstructive sleep apnea exhibit impaired endothelial function after myocardial infarction.
abstract: BACKGROUND
  Impaired brachial flow-mediated dilation (FMD) is associated with risk for subsequent cardiovascular events in patients after myocardial infarction (MI). These patients often have obstructive sleep apnea (OSA). We tested the hypothesis that patients with OSA post MI will exhibit more severe impairment in FMD.
  
  
  METHODS
  We studied 64 patients with MI admitted to our hospital. OSA was determined using polysomnography. FMD was measured using high-resolution ultrasonography, with researchers blind to the OSA diagnosis.
  
  
  RESULTS
  The mean age was 60 ± 11 years, and the mean BMI was 29 (26, 32 kg/m(2)), 84% of patients were men, 39% had moderate to severe OSA (apnea-hypopnea index [AHI] > 15), and 31% of the patients had mild OSA (5 ≤ AHI < 15). FMD was severely impaired in patients with moderate to severe OSA (0.8% ± 0.7%) as compared with patients without OSA (4.7% ± 0.8%, P = .001) and with mild OSA (3.9% ± 0.8%, P = .015). Linear regression showed that FMD was associated with log nocturnal nadir oxygen saturation (minSaO(2)) (β = 31.17, P = .0001), age (β = -0.11, P = .006). MinSaO(2) was an independent predictor of FMD after adjustment for possible confounders (β = 26.15, P = .001).
  
  
  CONCLUSIONS
  FMD is severely impaired in patients with moderate to severe OSA post MI, which may be partially related to nocturnal hypoxemia. Patients with OSA may, therefore, be at higher risk for subsequent cardiovascular events after an MI. Identifying and treating OSA may have important implications in the long-term prognosis of patients post MI. Further studies are necessary to determine if the presence of OSA would affect the long-term occurrence of cardiovascular events after an MI.
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: Fatima H
authors.initials: FH
authors.lastname: Sert Kuniyoshi
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: Prachi
authors.initials: P
authors.lastname: Singh
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: Apoor S
authors.initials: AS
authors.lastname: Gami
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: Arturo
authors.initials: A
authors.lastname: Garcia-Touchard
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: Christelle
authors.initials: C
authors.lastname: van der Walt
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: Snigdha
authors.initials: S
authors.lastname: Pusalavidyasagar
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Wright
authors.affiliation: Federal University of Espirito Santo, Vitoria, Brazil.
authors.forename: Elisardo Corral
authors.initials: EC
authors.lastname: Vasquez
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: Francisco
authors.initials: F
authors.lastname: Lopez-Jimenez
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN. Electronic address: somers.virend@mayo.edu.
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
mesh_terms: D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D010101:Oxygen Consumption; D017286:Polysomnography; D011379:Prognosis; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D014463:Ultrasonography; D014664:Vasodilation / Q000502:physiology*