The Study On Arousal During Sleep In Patients With Obstructive Sleep Apnea Hypopnea Syndrome

Objective: (l)To clarity the relationship and complementarity between breathing disorder related arousal index (B-ArI) and apnea plus hypopnea index (AHI). (2) To investigate the mechanism of arousal preliminarily. (3) To explore the relationship between arousal and apnea termination, daytime sleepiness, noctural heart rate variability (HRV), and state the clinical significance of arousal. (4)To expound the therapeutic effect of nCPAP on arousal.Methods: According to overnight polysomnography (PSG), 62 OSAHS (mild 17, moderate 22, severe 23) patients and 12 simple snorers were enrolled, except cardiopulmonary disorders or nervous system diseases. For all patients, EP, sleep latency (SL), AHI, minimum SaO2 (minSa02), number of oxygen desaturation>4% per hour (ODL4), percentage of time when oxygen saturation lower than 90% (SLT90%) and B-Arl were recorded, then correlation and multiple regression analysis were performed on B-Arl and other indices. To clarity the relation between arousal and noctural HRV, choose an hour continuous PSG record in non-rapid eye movement (NREM) in 27 patients with moderate to severe OSAHS. Compare the mean HR within 10 seconds before onset of each arousal with the peak HR within 10 seconds after onset of arousal during this hour. At the same time, calculate B-Arl and PRRI, then make correlation analysis. Furthermore, compare the A HR at apnea termination between 10 events with and without EEG arousal (matched according to minSa02) in NREM in 18 patientswith moderate to severe OSAHS. Finally, compare the improvement of all indices after nCPAP in 12 patients with OSAHS.Results: (l)B-ArI increased significantly in patients with OSAHS. B-Arl and AHI were positively correlated (r=0.94, P<0.001). When AHK20, B-Arl was higher than AHI, but when AHI50, B-Arl was lower than AHI significantly. (2) B-Arl was positively related to ODI4 (rs=0.84, P<0.05) and SLT90% (rs=0.82, P<0.05), but no relationship with minSa02 (P>.05). (3)B-ArI and EP were positively correlated (r=0.71, P<0.001), B-Arl and SL were negatively correlated (rs=0.66, P<0.001). (4)The peak HR within 10 seconds after onset of arousal was higher compared with the mean HR within 10 seconds before onset of arousal, B-Arl was positively related to PRRI (r=0.97, P<0.001). The A HR of those events with EEG arousal at apnea termination was higher than those without EEG arousal. (5)B-ArI decreased significantly after nCPAP treatment (P<0.001).Conclusions: (DB-Arl increases along with the severity of OSAHS. When AHK20, B-Arl is more sensitive than AHI. B-Arl is complementary to AHI and may be one of the useful indices for the evaluation of sleep breathing disorder. (2) B-Arl is related to hypoxemia, indicates a possible role for hypoxemia in the mechanism of arousal. (3)when AHISO, B-Arl is lower than AHI, suggests arousal may be not needed to apnea termination. (4)B-ArI can predict the degree of subject and object daytime sleepiness. (5)B-ArI and noctural HRV are correlated, shows arousal can influence cardiovascular regulation. Frequent arousal is one of the main reasons that cause cardiovascular consequences in patients with OSAHS. (6)NCPAP is effective to decrease B-Arl.