title: Napping reverses the salivary interleukin-6 and urinary norepinephrine changes induced by sleep restriction.
abstract: BACKGROUND
  Neuroendocrine and immune stresses imposed by chronic sleep restriction are known to be involved in the harmful cardiovascular effects associated with poor sleep.
  
  
  OBJECTIVE
  Despite a well-known beneficial effect of napping on alertness, its effects on neuroendocrine stress and immune responses after sleep restriction are largely unknown.
  
  
  METHODS
  This study was a strictly controlled (sleep-wake status, light environment, caloric intake), crossover, randomized design in continuously polysomnography-monitored subjects.
  
  
  METHODS
  The study was conducted in a laboratory-based study.
  
  
  METHODS
  The subjects were 11 healthy young men.
  
  
  METHODS
  We investigated the effects on neuroendocrine and immune biomarkers of a night of sleep restricted to 2 h followed by a day without naps or with 30 minute morning and afternoon naps, both conditions followed by an ad libitum recovery night starting at 20:00.
  
  
  METHODS
  Salivary interleukin-6 and urinary catecholamines were assessed throughout the daytime study periods.
  
  
  RESULTS
  The increase in norepinephrine values seen at the end of the afternoon after the sleep-restricted night was not present when the subjects had the opportunity to take naps. Interleukin-6 changes observed after sleep deprivation were also normalized after napping. During the recovery day in the no-nap condition, there were increased levels of afternoon epinephrine and dopamine, which was not the case in the nap condition. A recovery night after napping was associated with a reduced amount of slow-wave sleep compared to after the no-nap condition.
  
  
  CONCLUSIONS
  Our data suggest that napping has stress-releasing and immune effects. Napping could be easily applied in real settings as a countermeasure to the detrimental health consequences of sleep debt.
authors: Université Paris Descartes-Sorbonne Paris Cité, APHP, Hôtel Dieu de Paris, Centre du Sommeil et de la Vigilance (B.F., C.D., M.E., F.S., D.L.), EA 7330 VIFASOM, Paris, France; Université Paris Descartes-Sorbonne Paris Cité, APHP, Hôtel Dieu de Paris, Laboratoire de Chimie Clinique et Laboratoire de Biologie de la Nutrition (S.N., J-P.D.), EA 4466, Centre de Recherche Pharmaceutique de Paris, France; IRBA (Institut de Recherche Biomédicale des Armées) (C.D., F.S.), Unité Fatique Vigilance, Paris, France.
authors: Brice
authors: B
authors: Faraut
authors: Samir
authors: S
authors: Nakib
authors: Catherine
authors: C
authors: Drogou
authors: Maxime
authors: M
authors: Elbaz
authors: Fabien
authors: F
authors: Sauvet
authors: Jean-Pascal
authors: JP
authors: De Bandt
authors: Damien
authors: D
authors: Léger
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods; D009638:Norepinephrine / Q000652:urine*; D017286:Polysomnography; D012463:Saliva / Q000378:metabolism*; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000378:metabolism* / Q000652:urine*; D014851:Wakefulness / Q000502:physiology
chemical_list: D015850:Interleukin-6; D009638:Norepinephrine