title: Endothelial dysfunction in patients with obstructive sleep apnoea independent of metabolic syndrome.
abstract: BACKGROUND
  Obstructive sleep apnoea syndrome (OSAS), characterised by intermittent hypoxia/re-oxygenation, has been identified as an independent risk factor for cardiovascular diseases and endothelial dysfunction. Our aim was to investigate flow-mediated dilatation (FMD) in patients with obstructive sleep apnoea with and without metabolic syndrome.
  
  
  METHODS
  Fifty-two subjects with OSAS diagnosed by polysomnography were classified into 2 groups according to the presence and absence of the metabolic syndrome and also according to the severity: mild to moderate OSAS group and severe OSAS group. Endothelial function of the brachial artery was evaluated by using high-resolution vascular ultrasound. Endothelial-dependent dilatation (EDD) was assessed by establishing reactive hyperaemia and endothelial-independent dilatation (EID) was determined by using sublingual isosorbide dinitrate. Spearman correlation and regression analysis were performed.
  
  
  RESULTS
  EDD was not significantly different in patients with OSAS and metabolic syndrome as compared with OSAS without metabolic syndrome (4.62 +/- 0.69 versus 4.49 +/- 0.93, P >0.05).
  
  
  CONCLUSIONS
  Endothelial dysfunction in OSA may be independent of metabolic syndrome.
authors.affiliation: Isfahan University of Medical Sciences, Sheikh Mofid St 8164763831, Isfahan, Iran. amra@med.mui.ac.ir
authors.forename: Babak
authors.initials: B
authors.lastname: Amra
authors.forename: Elaheh
authors.initials: E
authors.lastname: Karbasi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Hashemi
authors.forename: Birgit
authors.initials: B
authors.lastname: Hoffmann-Castendiek
authors.forename: Mohammad
authors.initials: M
authors.lastname: Golshan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome; D008875:Middle Aged; D020181:Sleep Apnea, Obstructive / Q000150:complications*; D014463:Ultrasonography; D055815:Young Adult