- 作者：Robert Joseph Thomas ; Joseph E. Mietus ; Chung-Kang Peng ; Dan Guo ; David Gozal ; Hawley Montgomery-Downs ; Daniel J. Gottlieb ; Cheng-Yen Wang ; Ary L. Goldberger
- 关键词：Delta power ; Sleep spectrogram ; High frequency coupling ; Correlation ; Sleep effectiveness ; NREM slow oscillation
- 刊名：Sleep Medicine
- 出版年：January, 2014
- 年：2014
- 卷：15
- 期：1
- 页码：125-131
- 全文大小：944 K
Objectives
The physiologic relationship between slow-wave activity (SWA) (0-4 Hz) on the electroencephalogram (EEG) and high-frequency (0.1-0.4 Hz) cardiopulmonary coupling (CPC) derived from electrocardiogram (ECG) sleep spectrograms is not known. Because high-frequency CPC appears to be a biomarker of stable sleep, we tested the hypothesis that that slow-wave EEG power would show a relatively fixed-time relationship to periods of high-frequency CPC. Furthermore, we speculated that this correlation would be independent of conventional nonrapid eye movement (NREM) sleep stages.Methods
We analyzed selected datasets from an archived polysomnography (PSG) database, the Sleep Heart Health Study I (SHHS-I). We employed the cross-correlation technique to measure the degree of which 2 signals are correlated as a function of a time lag between them. Correlation analyses between high-frequency CPC and delta power (computed both as absolute and normalized values) from 3150 subjects with an apnea-hypopnea index (AHI) of 猢? events per hour of sleep were performed.
Results
The overall correlation (r) between delta power and high-frequency coupling (HFC) power was 0.40 卤 0.18 (P = .001). Normalized delta power provided improved correlation relative to absolute delta power. Correlations were somewhat reduced in the second half relative to the first half of the night (r = 0.45 卤 0.20 vs r = 0.34 卤 0.23). Correlations were only affected by age in the eighth decade. There were no sex differences and only small racial or ethnic differences were noted.
Conclusions
These results support a tight temporal relationship between slow wave power, both within and outside conventional slow wave sleep periods, and high frequency cardiopulmonary coupling, an ECG-derived biomarker of 鈥渟table鈥?sleep. These findings raise mechanistic questions regarding the cross-system integration of neural and cardiopulmonary control during sleep.