title: Association of obstructive sleep apnea with homocystein, nitric oxide and total antioxidant capacity levels in patients with or without coronary artery disease.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity and mortality. Deficiency of nitric oxide (NO) and plasma levels of homocystein have been implicated in the pathogenesis of cardiovascular disease. OSA results in oxygen desaturation and arousal from sleep. Free oxygen radicals can be produced by hypoxia-reoxygenation. To test for the hypothesis that OSA is associated with cardiovascular morbidity, we investigated levels of homocystein, NO and total antioxidant capacity in OSA patients with and without coronary artery disease (CAD) in comparison with normal subjects and patients with CAD without OSA.
  
  
  METHODS
  Polysomnography was performed in 27 patients who had a myocardial infarction and in 25 patients without evidence of CAD. Patients were grouped according their polysomnography results as OSA with CAD (group 1), OSA without CAD (group 2), CAD (group 3), and normal (group 4) . Levels of homocystein, NO and total antioxidant capacity were determined after an overnight fasting. Data were analysed with parametric and non parametric statistical tests.
  
  
  RESULTS
  According to apnea-hypopnea index (AHI) 44.4% of CAD patients were OSA. After polysomnographic evaluation, the patients were re-distributed as follows: OSA with CAD (n= 12), OSA without CAD (n= 14), CAD (n= 15), and normal (n= 11). Homocystein levels were higher in 3 groups compared to controls. AHI, MDI and desaturation time was higher in three -vessel disease compared to one and two- vessel diseases (p< 0.05). NO levels were correlated with the period of oxygen desaturation (r: -0.45, p= 0.031). The antioxidant capacity did not differ between OSA and healthy groups.
  
  
  CONCLUSIONS
  OSA is frequent in CAD. AHI, MDI and desaturation time are higher in patients with severe CAD. It is important to evaluate OSA patients for CAD.
authors.affiliation: Department of Internal Medicine, Unit of Intensive Care, Faculty of Medicine, Hacettepe University, Ankara, Turkey. ebru.ortac@hacettepe.edu.tr.
authors.forename: Ebru
authors.initials: E
authors.lastname: Ortaç Ersoy
authors.forename: Hikmet
authors.initials: H
authors.lastname: Fırat
authors.forename: Sevgi
authors.initials: S
authors.lastname: Akaydın
authors.forename: Yeşim
authors.initials: Y
authors.lastname: Özkan
authors.forename: Mine
authors.initials: M
authors.lastname: Durusu
authors.forename: Gülbahar
authors.initials: G
authors.lastname: Darılmaz Yüce
authors.forename: Recai
authors.initials: R
authors.lastname: Ergün
authors.forename: Arzu
authors.initials: A
authors.lastname: Topeli
authors.forename: Sadık
authors.initials: S
authors.lastname: Ardıç
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D003324:Coronary Artery Disease; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000097:blood*
chemical_list: D000975:Antioxidants; D006710:Homocysteine; D009569:Nitric Oxide