Τίτλος:
Daytime napping after a night of sleep loss decreases sleepiness,
improves performance, and causes beneficial changes in cortisol and
interleukin-6 secretion
Περίληψη:
Daytime napping after a night of sleep loss decreases sleepiness,
improves performance, and causes beneficial changes in cortisol and
interleukin-6 secretion. Am J Physiol Endocrinol Metab 292:E253-E261,
2007. First published August 29, 2006; doi:10.1152/ajpendo.00651.2005.-
Sleep loss has been associated with increased sleepiness, decreased
performance, elevations in inflammatory cytokines, and insulin
resistance. Daytime napping has been promoted as a countermeasure to
sleep loss. To assess the effects of a 2-h midafternoon nap following a
night of sleep loss on postnap sleepiness, performance, cortisol, and
IL-6, 41 young healthy individuals (20 men, 21 women) participated in a
7-day sleep deprivation experiment (4 consecutive nights followed by a
night of sleep loss and 2 recovery nights). One-half of the subjects
were randomly assigned to take a midafternoon nap (1400-1600) the day
following the night of total sleep loss. Serial 24-h blood sampling,
multiple sleep latency test (MSLT), subjective levels of sleepiness, and
psychomotor vigilance task (PVT) were completed on the fourth
(predeprivation) and sixth days (postdeprivation). During the nap,
subjects had a significant drop in cortisol and IL-6 levels (P < 0.05).
After the nap they experienced significantly less sleepiness (MSLT and
subjective, P < 0.05) and a smaller improvement on the PVT (P < 0.1). At
that time, they had a significant transient increase in their cortisol
levels (P < 0.05). In contrast, the levels of IL-6 tended to remain
decreased for similar to 8 h (P = 0.1). We conclude that a 2-h
midafternoon nap improves alertness, and to a lesser degree performance,
and reverses the effects of one night of sleep loss on cortisol and
IL-6. The redistribution of cortisol secretion and the prolonged
suppression of IL-6 secretion are beneficial, as they improve alertness
and performance.
Συγγραφείς:
Vgontzas, A. N.
Pejovic, S.
Zoumakis, E.
Lin, H. M. and
Bixler, E. O.
Basta, M.
Fang, J.
Sarrigiannidis, A. and
Chrousos, G. P.
