title: Benefits of napping and an extended duration of recovery sleep on alertness and immune cells after acute sleep restriction.
abstract: Understanding the interactions between sleep and the immune system may offer insight into why short sleep duration has been linked to negative health outcomes. We, therefore, investigated the effects of napping and extended recovery sleep after sleep restriction on the immune and inflammatory systems and sleepiness. After a baseline night, healthy young men slept for a 2-h night followed by either a standard 8-h recovery night (n=12), a 30-min nap (at 1 p.m.) in addition to an 8-h recovery night (n=10), or a 10-h extended recovery night (n=9). A control group slept 3 consecutive 8-h nights (n=9). Subjects underwent continuous electroencephalogram polysomnography and blood was sampled every day at 7 a.m. Leukocytes, inflammatory and atherogenesis biomarkers (high-sensitivity C-reactive protein, interleukin-8, myeloperoxidase, fibrinogen and apolipoproteins ApoB/ApoA), sleep patterns and sleepiness were investigated. All parameters remained unchanged in the control group. After sleep restriction, leukocyte and - among leukocyte subsets - neutrophil counts were increased, an effect that persisted after the 8-h recovery sleep, but, in subjects who had a nap or a 10-h recovery sleep, these values returned nearly to baseline. Inflammatory and atherogenesis biomarkers were unchanged except for higher myeloperoxidase levels after sleep restriction. The increased sleepiness after sleep restriction was reversed better in the nap and extended sleep recovery conditions. Saliva cortisol decreased immediately after the nap. Our results indicate that additional recovery sleep after sleep restriction provided by a midday nap prior to recovery sleep or a sleep extended night can improve alertness and return leukocyte counts to baseline values.
authors.affiliation: Sleep Laboratory, (ULB 222 Unit), CHU de Charleroi, A. Vésale Hospital, Université Libre de Bruxelles, Montigny-le-Tilleul, Belgium.
authors.forename: Brice
authors.initials: B
authors.lastname: Faraut
authors.forename: Karim Zouaoui
authors.initials: KZ
authors.lastname: Boudjeltia
authors.forename: Michal
authors.initials: M
authors.lastname: Dyzma
authors.forename: Alexandre
authors.initials: A
authors.lastname: Rousseau
authors.forename: Elodie
authors.initials: E
authors.lastname: David
authors.forename: Patricia
authors.initials: P
authors.lastname: Stenuit
authors.forename: Thierry
authors.initials: T
authors.lastname: Franck
authors.forename: Pierre
authors.initials: P
authors.lastname: Van Antwerpen
authors.forename: Michel
authors.initials: M
authors.lastname: Vanhaeverbeek
authors.forename: Myriam
authors.initials: M
authors.lastname: Kerkhofs
mesh_terms: D000328:Adult; D050197:Atherosclerosis / Q000276:immunology; D001288:Attention / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D007111:Immunity, Cellular / Q000502:physiology*; D007249:Inflammation / Q000276:immunology; D007958:Leukocyte Count; D008297:Male; D009504:Neutrophils / Q000502:physiology; D009195:Peroxidase / Q000378:metabolism; D017286:Polysomnography; D012463:Saliva / Q000378:metabolism; D012890:Sleep / Q000276:immunology*; D012892:Sleep Deprivation / Q000276:immunology*; D012984:Software; D055815:Young Adult
chemical_list: D009195:Peroxidase; D006854:Hydrocortisone