title: Effect of continuous positive airway pressure therapy on aortic stiffness in patients with obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  The most significant complications seen in patients with obstructive sleep apnea syndrome (OSAS) are associated with the cardiovascular system. The present study assessed aortic stiffness in patients with OSAS and evaluated the effect of continuous positive airway pressure (CPAP) therapy on aortic stiffness.
  
  
  METHODS
  Twenty-four patients with newly diagnosed, previously untreated, moderate or severe OSAS (apnea-hypopnea index > 15) and a control group of 17 healthy patients were included in the study. M-mode recordings of the ascending aorta were taken from the parasternal long axis by echocardiograhy, and systolic and diastolic diameters of the aorta were measured. Aortic elastic parameters, aortic strain, and distensibility were calculated. Measurements were repeated after 6 months of CPAP therapy in patients with OSAS and were compared with baseline values.
  
  
  RESULTS
  In patients with OSAS, compared with the control group, aortic strain (6.7%+/- 2.1% vs. 12.4%+/- 3.1%; P < 0.001) and aortic distensibility (2.8 +/- 0.9 x 10(-6) cm(2) dyn(-1) vs. 5.5 +/- 1.7 x 10(-6) cm(2) dyn(-1); P < 0.001) were evidently lower, and there was a significant correlation between aortic elastic parameters and AHI. After a 6-month course of CPAP therapy, significant increases were observed in aortic strain (6.1%+/- 1.5% vs. 7.3%+/- 1.7%; P < 0.001) and aortic distensibility (2.5 +/- 0.7 x 10(-6) cm(2) dyn(-1) vs. 3.1 +/- 0.9 x 10(-6) cm(2) dyn(-1); P < 0.001) in patients with OSAS.
  
  
  CONCLUSIONS
  Aortic strain and distensibility were lower in patients with OSAS than in control patients, and CPAP treatment provided improvement in aortic elastic parameters.
authors.affiliation: Ataturk Education and Research Hospital, Cardiology Department, Ankara, Turkey.
authors.forename: Telat
authors.initials: T
authors.lastname: Keles
authors.forename: Tahir
authors.initials: T
authors.lastname: Durmaz
authors.forename: Nihal Akar
authors.initials: NA
authors.lastname: Bayram
authors.forename: Bulent
authors.initials: B
authors.lastname: Ciftci
authors.forename: Ekrem
authors.initials: E
authors.lastname: Yeter
authors.forename: Murat
authors.initials: M
authors.lastname: Akcay
authors.forename: Engin
authors.initials: E
authors.lastname: Bozkurt
mesh_terms: D000328:Adult; D001011:Aorta / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D055119:Elastic Modulus; D005260:Female; D006801:Humans; D008297:Male; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D016896:Treatment Outcome; D014463:Ultrasonography