Respiratory control in obstructive sleep apnea hypopnea syndrome
Wang, W.; Kang, J.; Jin, G.-m.; Wang, Q.-y.; Hou, X.-m.; Yu, R.-j.
Zhonghua Nei Ke Za Zhi 43(9): 647-650
2004
ISSN/ISBN: 0578-1426 PMID: 15500773 Document Number: 569298
To evaluate the role of ventilatory control in obstructive sleep apnea hypopnea syndrome (OSAHS). 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). (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). 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.