title: Acute Changes in Inflammatory Biomarker Levels in Recreational Runners Participating in a Marathon or Half-Marathon.
abstract: BACKGROUND
  Strenuous physical activity activates the participant's immune responses; however, few studies exist, observing exercise-induced simultaneous changes in mediators of inflammation.
  
  
  METHODS
  We examined individual responses in soluble urokinase-type plasminogen activator receptor (suPAR), a marker of immune activation, soluble endocytic receptor for haptoglobin-hemoglobin complexes (CD163), a marker of monocyte-macrophage activation, C-reactive protein (CRP), and pro- and anti-inflammatory cytokines from blood samples drawn at baseline, at 3- and 48-h post-races from recreational runners who successfully completed the marathon (199 ± 8 min, n = 4) or half-marathon (132 ± 4 min, n = 4) run. For comparisons, biomarkers reflecting muscle, heart, kidney, and liver functions were measured.
  
  
  RESULTS
  Significant 3-h post-race increases occurred in levels of suPAR (p < 0.01), CD163 (p < 0.05), white blood cells (p < 0.001), pro-inflammatory cytokines, interleukin-6 (IL-6) (p < 0.001), IL-8 (p < 0.05), and anti-inflammatory cytokine IL-10 (p < 0.05), whereas tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) remained relatively stable. Full-marathon running lead to more pronounced increases in suPAR, CD163, IL-8, and IL-10 than half-marathon running. In addition, 3-h post-race increases of all these parameters correlated significantly with changes in serum TNF-α and cortisol. The 48-h levels of serum suPAR and both pro- and anti-inflammatory cytokines had decreased to baseline levels, whereas CRP, a marker of acute phase response, increased in those with the most prominent IL-6 and IL-10 elevations in their preceding samples. The highest suPAR, CRP, IL-6, TNF-α, IL-10, and cortisol levels were noted in the individual with the most severe post-race fatigue.
  
  
  CONCLUSIONS
  Prolonged running increases mediators of inflammation in an exercise-dose-dependent manner which should be considered in the assessment of health status of physically active individuals after recent acute bouts of strenuous exercise.
authors.affiliation: Department of Surgery, Oulu University Hospital, P.O. Box 21, 90029 OYS, Oulu, Finland.
authors.forename: Markus
authors.initials: M
authors.lastname: Niemelä
authors.affiliation: Department of Laboratory Medicine and Medical Research Unit, Seinäjoki Central Hospital and University of Tampere, Hanneksenrinne 7, 60220, Seinäjoki, Finland.
authors.forename: Päivikki
authors.initials: P
authors.lastname: Kangastupa
authors.affiliation: Department of Laboratory Medicine and Medical Research Unit, Seinäjoki Central Hospital and University of Tampere, Hanneksenrinne 7, 60220, Seinäjoki, Finland. onni.niemela@epshp.fi.
authors.forename: Onni
authors.initials: O
authors.lastname: Niemelä
authors.affiliation: Medical Informatics and Statistics Research Group, University of Oulu, Oulu, Finland.
authors.forename: Risto
authors.initials: R
authors.lastname: Bloigu
authors.affiliation: Department of Surgery, Oulu University Hospital, P.O. Box 21, 90029 OYS, Oulu, Finland.
authors.forename: Tatu
authors.initials: T
authors.lastname: Juvonen