title: Microvascular endothelial function in obstructive sleep apnea: Impact of continuous positive airway pressure and mandibular advancement.
abstract: OBJECTIVE
  Endothelial dysfunction has been proposed as a potential mechanism implicated in the pathogenesis of cardiovascular complications of obstructive sleep apnea syndrome (OSAS). This study aimed to evaluate the microvascular endothelial function (MVEV) in OSAS and the impact on MVEF of 2 months of treatment with continuous positive airway pressure (CPAP) and mandibular advancement device (MAD).
  
  
  METHODS
  Microvascular reactivity was assessed using laser Doppler flowmetry combined with acetylcholine (Ach) and sodium nitroprusside (SNP) iontophoresis in 24 OSAS patients and 9 control patients. In 12 of the 24 OSAS patients, microvascular reactivity was reassessed after 2 months of CPAP and MAD using a randomized cross-over design.
  
  
  RESULTS
  Ach-induced vasodilation was significantly lower in OSAS patients than in matched controls and correlated negatively with apnea hypopnea index (r=-0.49, p<0.025) and nocturnal oxygen desaturations (r=-0.63, p<0.002). Ach-induced vasodilation increased significantly with both CPAP and MAD. The increase in Ach-induced vasodilation under OSAS treatment correlated with the decrease in nocturnal oxygen desaturations (r=0.48, p=0.016).
  
  
  CONCLUSIONS
  Our study shows an impairment of MVEF in OSAS related to OSAS severity. Both CPAP and MAD treatments were associated with an improvement in MVEF that could contribute to improve cardiovascular outcome in OSAS patients.
authors.affiliation: Département de Pneumologie, CHU, 4 Rue Larrey, 49033 Angers Cedex, France.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Trzepizur
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gagnadoux
authors.forename: Pierre
authors.initials: P
authors.lastname: Abraham
authors.forename: Pascal
authors.initials: P
authors.lastname: Rousseau
authors.forename: Nicole
authors.initials: N
authors.lastname: Meslier
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Saumet
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Racineux
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D018592:Cross-Over Studies; D004730:Endothelium, Vascular / Q000503:physiopathology*; D006801:Humans; D008297:Male; D019186:Mandibular Advancement / Q000379:methods*; D055806:Microvessels / Q000502:physiology*; D008875:Middle Aged; D017286:Polysomnography; D012212:Rheology; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D014664:Vasodilation; D055815:Young Adult