title: [Effect of acute hypoxia and hypercapnia on arterial stiffness and blood pressure in patients with obstructive sleep apnea hypopnea syndrome].
abstract: OBJECTIVE
  To investigate the effect of acute hypoxia and/or hypercapnia on cardio-ankle vascular index (CAVI) and blood pressure (BP) in patients with obstructive sleep apnea hypopnea syndrome (OSAHS).
  
  
  METHODS
  CAVI and blood pressure were measured before and after isocapnic hypoxic, hyperoxia hypercapnic, and hypoxic and hypercapnic challenge in 28 non-hypertensive patients with OSAHS (AHI > 10/h) and 26 healthy controls (AHI < 5/h), respectively. They were matched for age and sex. Hypoxia and hypercapnia were induced by re-breathing technique.
  
  
  RESULTS
  The 2 groups had no differences in regard to systolic (SBP) and diastolic BP(DBP) and CAVI. After hypercapnic challenge, SBP increased significantly in both groups. CAVI decreased significantly in controls, but not in OSAHS. Hypoxia induced significant increase of CAVI, but not in OSAHS. SBP and DBP maintained to the pre-challenge levels in both group. Hypercapnia and hypoxia together caused increase of SBP in both groups, and CAVI increased significantly in controls, but not in OSAHS.
  
  
  CONCLUSIONS
  Acute hypoxia and hypercapnia exposure caused change of arterial stiffness and BP in both control and patients with sleep apnea hypopnea syndrome. However, CAVI responses to hypoxic and/or hypercapnic challenge were blunted in patients with OSAHS.
authors.affiliation: Department of Pulmonary Medicine, First People's Hospital of Yunnan Province, Kunming 650032, China.
authors.forename: Yun-Hui
authors.initials: YH
authors.lastname: Lü
authors.forename: Zhong-Ming
authors.initials: ZM
authors.lastname: He
authors.forename: Xiao-Song
authors.initials: XS
authors.lastname: Dong
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Xu
authors.initials: X
authors.lastname: Han
authors.forename: Pei
authors.initials: P
authors.lastname: An
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Quan-Ying
authors.initials: QY
authors.lastname: He
authors.forename: Fang
authors.initials: F
authors.lastname: Han
mesh_terms: D000328:Adult; D001158:Arteries / Q000503:physiopathology*; D001794:Blood Pressure; D016022:Case-Control Studies; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D006935:Hypercapnia; D000860:Hypoxia; D008297:Male; D008875:Middle Aged; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D014655:Vascular Resistance