title: Blunted IL-6 and IL-10 response to maximal aerobic exercise in patients with traumatic brain injury.
abstract: BACKGROUND
  In healthy individuals, strenuous exercise typically results in a transient increase in the inflammatory cytokine, interleukin-6 (IL-6). This increase in IL-6 is reported to have pleiotropic effects including increased glucose uptake, increased fat oxidation, and anti-inflammatory actions.
  
  
  OBJECTIVE
  The purpose of this study was to determine if patients with a traumatic brain injury (TBI) have a differential cytokine response to exercise compared to healthy control subjects (CON).
  
  
  METHODS
  Eight patients with a TBI and eight age- and sex-matched controls completed an exercise test to volitional exhaustion. Metabolic data were collected continuously, and blood was collected at baseline, immediately post-exercise, and every 10 min for an hour post-exercise. Serum was analyzed for IL-6, tumor necrosis factor-alpha, interleukin-10 (IL-10), and cortisol.
  
  
  RESULTS
  Peak oxygen consumption (CON 33 ± 2 ml kg(-1) min(-1); TBI 29 ± 2 ml kg(-1) min(-1)) and respiratory exchange ratio during exercise were equivalent between groups. There were no baseline differences between groups for cytokine or cortisol concentrations. Exercise did not increase IL-6 in TBI, whereas IL-6 was elevated from baseline in CON at 0, 40, and 50 min post-exercise (p < 0.05). IL-10 and cortisol increased from baseline in CON at 40 min post-exercise (p < 0.05).
  
  
  CONCLUSIONS
  These data indicate that patients recovering from TBI have blunted IL-6, IL-10, and cortisol responses following a peak exercise test compared to non-TBI controls. This lack of an exercise response may represent impaired hypothalamic-pituitary-adrenal axis function.
authors.affiliation: Miami University, Oxford, OH, USA, timmerkl@miamioh.edu.
authors.forename: Kyle L
authors.initials: KL
authors.lastname: Timmerman
authors.forename: William E
authors.initials: WE
authors.lastname: Amonette
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Markofski
authors.forename: Hayden A
authors.initials: HA
authors.lastname: Ansinelli
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Gleason
authors.forename: Blake B
authors.initials: BB
authors.lastname: Rasmussen
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Mossberg
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000378:metabolism*; D016022:Case-Control Studies; D015444:Exercise; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D016753:Interleukin-10 / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D006854:Hydrocortisone