0069 Spectral analyses of slow wave sleep and rapid eye movement sleep are associated with changes in continuous nocturnal blood pressure

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Department of Kinesiology and Integrative Physiology



Slow wave (SWS) and rapid eye movement (REM) sleep are both associated with dynamic changes in nocturnal blood pressure (BP). Specifically, SWS is often associated with the greatest reductions of nocturnal BP, while episodic increases of BP are a hallmark of REM sleep. While it is widely assumed that the respective intensities of SWS and REM impact nocturnal BP, definitive studies examining these intensities via spectral analysis during continuously recorded BP are lacking. Moreover, while increases of alpha frequencies (i.e., alpha intrusion) during REM are reported in some pathological conditions, the relation between alpha intrusion and REM BP is unknown.


Thirteen participants (6 female, 22±1 years, 28±1 kg/m2) were equipped with overnight finger plethysmography (NOVA, Finapres) and standard 10-lead polysomnography. Central and occipital leads were analyzed using a short-term Fourier transform function to quantify 1) delta density using delta frequencies (0.5-4 Hz) in the first and second SWS cycles and 2) alpha intrusion using alpha frequencies (8-12 Hz) in the final REM episode. Continuous systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and heart rate (HR) were recorded during wake and sleep.


BP was significantly reduced during the first (SAP, 114±4 to 99±4 mmHg; DAP, 68±3 to 57±3 mmHg; p0.05), cycle of SWS when compared to wake. Changes in delta density across the SWS stages were significantly correlated with changes in SAP (r =-0.69, p=0.03) and DAP (r=-0.71, p=0.02). During REM, acute episodes of alpha intrusion were associated with increases of SAP (119±5 mmHg to 123±5 mmHg; p=0.039) and DAP (69±5 mmHg to 72±5 mmHg; p=0.043), but not HR.


Our findings suggest that the intensity of SWS is associated with greater reductions in nocturnal BP, and that episodes of alpha intrusion increase REM BP. These findings support growing evidence that both SWS and REM are important to cardiovascular health.

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