title: Inflammation and sleep in healthy individuals.
abstract: OBJECTIVE
  Inflammation is relatively common in individuals with a sleep disorder and is associated with quality of sleep. The purpose of this study was to examine whether inflammation is associated with quality of sleep in healthy individuals.
  
  
  METHODS
  Observational study in a General Clinical Research Center.
  
  
  METHODS
  This study characterized inflammation and polysomno-graphically verified sleep in 124 African American and Caucasian American women and men without a sleep disorder.
  
  
  RESULTS
  Circulating levels of 3 markers and/or mediators of inflammation known to be elevated in sleep disorders and in cardiovascular disease were determined (interleukin-6 [IL-6] endothelin-1 [ET-1], soluble intercellular adhesion molecule-1 [sICAM-1]). Sleep was characterized by polysomnography. Multiple linear regression analyses showed that increasing age, male sex, and African American ethnicity were independently associated with poorer sleep. After controlling for these variables, higher levels of ET-1 were independently associated with greater sleep latency (P < or = 0.01), greater rapid eye movement (REM) latency (P < or = 0.01), more slow wave sleep (P < or = 0.05), and less stage 1 sleep (P < or = 0.01). Higher IL-6 levels were independently associated with greater REM latency (P < or = 0.05).
  
  
  CONCLUSIONS
  The findings suggest that, in individuals without a known sleep disorder, ET-1, a potent vasoconstrictor and mediator of inflammation, is associated with more deep sleep, whereas both ET-1 and IL-6 are associated with increased latency of sleep and of REM. The findings underscore the complex relationships between peripheral markers of inflammation and sleep.
authors.affiliation: Department of Psychiatry, University of California San Diego, School of Medicine, La Jolla, CA, USA. pmills@ucsd.edu
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Mills
authors.forename: Roland
authors.initials: R
authors.lastname: von Känel
authors.forename: Daniel
authors.initials: D
authors.lastname: Norman
authors.forename: Loki
authors.initials: L
authors.lastname: Natarajan
authors.forename: Michael G
authors.initials: MG
authors.lastname: Ziegler
authors.forename: Joel E
authors.initials: JE
authors.lastname: Dimsdale
mesh_terms: D000328:Adult; D015415:Biomarkers; D003327:Coronary Disease / Q000276:immunology*; D019332:Endothelin-1 / Q000276:immunology*; D005260:Female; D006304:Health Status; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology*; D015850:Interleukin-6 / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012890:Sleep / Q000502:physiology*
chemical_list: D015415:Biomarkers; D019332:Endothelin-1; D015850:Interleukin-6; D018799:Intercellular Adhesion Molecule-1