Partial sleep deprivation: impact on the architecture and quality of sleep.
OBJECTIVE
The study was aimed at the examination of the acute and cumulative impact of partial sleep deprivation (PSD) on architecture and quality of sleep, on circadian rhythm and on daytime fatigue.


METHODS
Time in bed for 16 healthy male volunteers was reduced from 8 to 5h during four consecutive nights, followed by two recovery nights. This scheme matches the terms of service and sleep rhythms of rescue helicopter pilots in Germany. Polysomnography was recorded during each night, and motor activity and body core temperature were recorded continuously. Subjective sleep quality and alertness were acquired by questionnaires.


RESULTS
In the course of PSD, electroencephalography (EEG) showed a reduction of S1 and S2 (p=0.039), whereas S3, S4 (0.024) and rapid eye movement (REM; p=0.030) sleep increased. Subjective sleep quality improved, while sleep need (p<0.001) and fatigue (p<0.001) deepened. These effects declined rapidly after one recovery night.


CONCLUSIONS
PSD alters sleep and daytime alertness. The results indicate that not only slow wave sleep (SWS) but also REM is important for sleep. Sleep became more effective when wake periods and sleep latencies decreased, thereby improving subjective sleep quality. Sleepiness, sleep need and fatigue increased immediately and accumulated throughout the restricting procedure.
Elmenhorst
Eva-Maria
EM
DLR-Institute of Aerospace Medicine, Cologne, Germany. eva-maria.elmenhorst@dlr.de
Elmenhorst
David
D
Luks
Norbert
N
Maass
Hartmut
H
Vejvoda
Martin
M
Samel
Alexander
A
D000328:Adult; D001143:Arousal / Q000502:physiology; D001359:Aviation / Q000706:statistics & numerical data; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D012720:Severity of Illness Index; D012892:Sleep Deprivation / Q000150:complications* / Q000175:diagnosis*; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000209:etiology*; D012895:Sleep, REM / Q000502:physiology; D055815:Young Adult