The Influence Of Sleep Stage To RR Intervals Of Patients With Obstructive Sleep Apnea Syndrome

Objective: To investigate changing of the autonomic nervous system (ANS)activity induced by obstructive sleep apnea (OA) during different sleep stages byanalyzing the changes of RR intervals in Electrocardiogram (ECG) monitoring byPolysomnography (PSG).Methods:30male patients with diagnosed obstructive sleep apnea syndrome(OSAS) by PSG were enrolled in the study. The RR intervals, sleep stages andrelative data were extracted during the OA (Event), as well as a15-second periodbefore and after the OA (Pre-and Post-) and1minute respiratory stable period(Stable). Then, the heart rate variability (HRV) parameters were calculated. Toinvestigate the influence of sleep stage to ANS, the HRV parameters during sleepstage1and2(S1-2) and rapid eye movement stage (REM) was classified andcompared.Results:(1) There were significant differences among the three intervals duringOA (all P<0.001). Except the overall trend of ΔRR-Mean was: Pre-<Post-<Event.The overall trend of other HRV parameters (such as RR-Mean, RR-SD) was: Event<Pre-<Post-. Both in S1-2and in REM sleep, RR-Mean and RR-SD shifted to lowestduring OA, while the trends shifted back again after OA.(2) During Pre-and Event,RR-Mean in REM was lower than in S1-2(P<0.01; P<0.001); however, there was nosignificant difference between REM and S1-2during Post-.(3) No matter in S1-2orREM, RR-Mean during Event was significant lower than Stable (P<0.001; P<0.01).(4) Both in S1-2and REM, correlation analysis showed that RR-Mean in the threeintervals was positive correlated to apnea-hypopnea index (AHI); moreover, in REMRR-SD also showed positive correlation to AHI during Event and Post-. In S1-2,RR-Mean and RR-SD in the three intervals were negative correlated to age; however,in REM RR-Mean and RR-SD were negative correlated to age only during Pre-.Conclusions:(1) Both in S1-2and REM, OA induced a faster heart rate with lower vibration. The sympathetic nervous system (SNS) activity showed a dominatedlevel when OA occurred. However, there was a compensatory revert after OA.(2)During Pre-and Event, the SNS activity dominated in REM.(3) Both in S1-2andREM, the SNS activity was higher during OA than Stable.(4) Both in S1-2and REM,the SNS activity was negative correlated to AHI in the three intervals, and thisrelation was more remarkable in REM. However, age showed positive correlations tothe SNS activity in the three intervals, and this relation was more remarkable in S1-2.