Self-Awakening Prevents Acute Rise in Blood Pressure and Heart Rate at the Time of Awakening in Elderly People

Abstract

Self-awakening, waking up at a designated time decided before sleeping, could prevent failure in the blood circulation vessel system such as heart attack, acute increases in heart rate or blood pressure upon waking. Previous research showed that anticipatory changes occurred in heart rate prior to awakening from a short nap by means of self-awakening for young participants. However, the effects of self-awakening remained unclear for elderly people. The present study examined the effects of self-awakening on heart rate and blood pressure in a short afternoon nap (20 min) among the elderly. Nine participants [74.1 (SD = 5.01) years old] underwent both self-awakening and forced-awakening conditions. In the self-awakening condition, it was revealed that blood pressure gradually increased before the scheduled time of awakening, and that heart rate did not show a rapid increase at arousal. In contrast, forced-awakening induced acute increases in both heart rate and blood pressure. These results suggest that self-awakening facilitates a more smooth transition from sleep to wakefulness via autonomic activation before the time of self-awakening.

Electroencephalogram activity before self-awakening

“…Rapid secretion of ACTH within the last hour before awakening (when participants anticipate waking up at a predetermined time) 4 and blood pressure/heart rate increases before self‐awakening 5,6 both suggest that self‐awakening facilitates natural awakening and diminishes sleep inertia 3,9 . The present study found that sigma band power gradually decreased before awakening on self‐awakening nights.…”

“…However, the psychophysiological mechanism of self‐awakening remains unknown. The findings that adrenocorticotropin (ACTH) increased 1 h before self‐awakening, 4 and blood pressure and heart rate increased several minutes before self‐awakening, 5,6 suggest that electroencephalogram (EEG) activities would also change before awakening on self‐awakening nights. Tassi et al 7 .…”

Self‐awakening improves alertness in the morning and during the day after partial sleep deprivation

“…SA enables people to wake up at a predetermined time successfully and accurately and improves morning alertness by eliminating sleep inertia (Ikeda and Hayashi, ), a transitional state from sleep to wakefulness accompanied by incomplete arousal (Tassi and Muzet, ). SA facilitates the transition from sleep to waking at a predetermined waking time by collaborating with inherent sleep–wake regulation, thus coinciding with various physiological changes in vivo , such as increments in serum adrenocorticotrophic concentrations (Born et al ., ), sympathetic activity (Kaida et al ., ), right prefrontal oxygen metabolism (Aritake et al ., ) and a decrement in sigma‐band electroencephalogram (EEG) power (Ikeda and Hayashi, ) in the pre‐awakening period. Sleep inertia varies according to pre‐awakening sleep states, such as the sleep stage (Cavallero and Versace, ), circadian phase (Scheer et al ., ) and residual homeostatic demands (Dinges et al ., ); therefore, when the previous night's sleep is restricted, sleep inertia increases the following morning (Cavallero and Versace, ).…”