title: [Respiratory control in obstructive sleep apnea hypopnea syndrome].
abstract: OBJECTIVE
  To evaluate the role of ventilatory control in obstructive sleep apnea hypopnea syndrome (OSAHS).
  
  
  METHODS
  Thirty-five patients with OSAHS were compared with 15 obese controls in pulmonary function, hypoxic ventilatory response (HVR), hypercapnic ventilatory response (HCVR) and polysomnography (PSG).
  
  
  RESULTS
  (1) There were no differences in HVR and HCVR between patients with OSAHS and the control (t = 1.28, 0.57; P > 0.05). In OSAHS patients, HVR was correlated with nadir nocturnal oxygen saturation (MmS(P)O(2)) (r = -0.54, P < 0.01) and HCVR (r = 0.57, P < 0.01). (2) Patients with mild and moderate OSAHS had higher HVR than those with severe OSAHS (t = 2.74, P < 0.01). When 5 < or = apnea and hypopnea index (AHI) < 40, HVR was negatively correlated to forced expiratory volume in one second (FEV(1))/peak expiratory flow (PEF) (r = -0.42, P < 0.05) and AHI (r = -0.68, P < 0.01). For those whose AHI > or = 40, HVR was negatively correlated with MmSpO(2) (r = -0.58, P < 0.05) and positively correlated with HCVR (r = 0.59, P < 0.05).
  
  
  CONCLUSIONS
  In OSAHS patients, HCVR did not show significant change, but HVR showed two phasic change-increase first and then decrease-following the elevation of AHI, which was also related to MmSpO(2) and HCVR.
authors.affiliation: Institute of Respiratory Disease, the First Affiliated Hospital of China Medical University, Shenyang 110001, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Kang
authors.forename: Guang-ming
authors.initials: GM
authors.lastname: Jin
authors.forename: Qiu-yue
authors.initials: QY
authors.lastname: Wang
authors.forename: Xian-ming
authors.initials: XM
authors.lastname: Hou
authors.forename: Run-jiang
authors.initials: RJ
authors.lastname: Yu
mesh_terms: D000328:Adult; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology; D017286:Polysomnography; D012123:Pulmonary Ventilation / Q000502:physiology; D012119:Respiration; D012129:Respiratory Function Tests; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*