Short-term reliability of inflammatory mediators and response to exercise in the heat.
Prospective application of serum cytokines, lipopolysaccharide (LPS), and heat shock proteins (eHSPs) requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (7 day) reliability (at rest, n = 12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60-min cycling, 34.5°C and 70% RH, n = 20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin-6 (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and LPS. Test-retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-participant variation were IL-6 (19%, ±20%; CV, ±95% confidence limits (CL)) and LPS (23%, ±13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28-38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ±11%, P = < 0.001) and although CRP had a modest CV (12%, ±7%), it increased substantially post-exercise (P = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation.
a Department of Sport and Exercise Science , James Cook University , Cairns , Australia.|b Faculty of Sport and Health Sciences , University of St Mark and St John , Plymouth , UK.
Joshua H
http://orcid.org/0000-0003-3000-2747
JH
Guy
a Department of Sport and Exercise Science , James Cook University , Cairns , Australia.|b Faculty of Sport and Health Sciences , University of St Mark and St John , Plymouth , UK.
Andrew M
AM
Edwards
c College of Public Health, Medical and Veterinary Sciences , James Cook University , Cairns , Australia.
Catherine M
CM
Miller
a Department of Sport and Exercise Science , James Cook University , Cairns , Australia.
Glen B
GB
Deakin
a Department of Sport and Exercise Science , James Cook University , Cairns , Australia.|d Department of Physiology , Australian Institute of Sport , Canberra , Australia.
David B
DB
Pyne
D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D050884:HSP72 Heat-Shock Proteins / Q000097:blood; D018882:Heat Stress Disorders / Q000097:blood / Q000175:diagnosis*; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D006813:Humidity / Q000009:adverse effects; D007075:Immunoglobulin M / Q000097:blood; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D008070:Lipopolysaccharides / Q000097:blood; D008297:Male; D015203:Reproducibility of Results; D055815:Young Adult
D015415:Biomarkers; D050884:HSP72 Heat-Shock Proteins; D007075:Immunoglobulin M; D018836:Inflammation Mediators; D015850:Interleukin-6; D008070:Lipopolysaccharides; D002097:C-Reactive Protein
Lipopolysaccharide; heat shock proteins; heat tolerance; inflammatory cytokines