title: Vascular endothelial dysfunction in patients with mild obstructive sleep apnea syndrome.
abstract: BACKGROUND
  We investigated endothelial dysfunction, an early manifestation of atherosclerosis, in patients with mild obstructive sleep apnea syndrome (OSAS) (5/h < AHI < 15/h).
  
  
  METHODS
  Endothelium-dependent and -independent vasodilatory function was tested in 10 patients with mild OSAS, 12 healthy controls and 20 subjects with moderate to severe OSAS using the hand vein compliance technique.
  
  
  RESULTS
  Maximum endothelium-dependent vasodilation to bradykinin (Emax) was significantly blunted in patients with mild OSAS (68.6 +/- 30.2 %) compared to healthy controls (94.8 +/- 9.5 %; p < 0.05; moderate to severe OSAS: 57.1 +/- 23.4 %; p = 0.33). Mean endothelium-independent venodilation was not altered. After 160.7 +/- 82.2 nights of CPAP therapy, mean Emax was significantly improved to 90.8 +/- 23.8 % (p < 0.01 vs. baseline; p = 0.7 vs. healthy controls) in 7 patients with mild OSAS.
  
  
  CONCLUSIONS
  Systemic endothelium-dependent venodilation is markedly reduced in subjects with mild OSAS, which may imply adverse cardiovascular consequences. CPAP-treatment leads to a sustained restoration of endothelial dysfunction in these patients and is thus highly recommended.
authors.affiliation: University Hospital Bergmannsheil, Ruhr-University Bochum, Medical Clinic III, Pulmonary Medicine, Allergology, Sleep- and Ventilatory Medicine, Bochum, Germany. hans-werner.duchna@ruhr-uni-bochum.de
authors.forename: Hans-Werner
authors.initials: HW
authors.lastname: Duchna
authors.forename: Riccardo
authors.initials: R
authors.lastname: Stoohs
authors.forename: Christian
authors.initials: C
authors.lastname: Guilleminault
authors.forename: Marie
authors.initials: M
authors.lastname: Christine Anspach
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schultze-Werninghaus
authors.forename: Maritta
authors.initials: M
authors.lastname: Orth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D050197:Atherosclerosis / Q000175:diagnosis* / Q000209:etiology; D015992:Body Mass Index; D001920:Bradykinin / Q000008:administration & dosage; D045422:Continuous Positive Airway Pressure; D003627:Data Interpretation, Statistical; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000503:physiopathology*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage; D018579:Patient Selection; D017286:Polysomnography; D012044:Regression Analysis; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D014664:Vasodilation; D014665:Vasodilator Agents / Q000008:administration & dosage; D014680:Veins / Q000503:physiopathology
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin; D001920:Bradykinin