Relationship between inflammatory cytokines and indices of cardiac dysfunction following intense endurance exercise

La Gerche, Andre; Inder, Warrick J.; Roberts, Timothy J.; Brosnan, Maria J.; Heidbuchel, Hein; Prior, David L.

doi:10.1371/JOURNAL.PONE.0130031

Title

Relationship between inflammatory cytokines and indices of cardiac dysfunction following intense endurance exercise

Author

La Gerche, Andre

Inder, Warrick J.

Roberts, Timothy J.

Brosnan, Maria J.

Heidbuchel, Hein

Prior, David L.

Abstract

Objectives Pro-inflammatory cytokines have been noted to increase following exercise but their relationship to exercise-induced cardiac dysfunction has not previously been investigated. We sought to evaluate whether exercise-induced cardiac dysfunction was associated with increases in cytokines, particularly the pro-inflammatory cytokines IL-1 beta, IL-12p70 and TNF alpha, which have been most implicated in cardiac pathology. Methods 40 well-trained endurance athletes underwent evaluation prior to and immediately following one of four endurance sporting events ranging from 3 to 11 hours duration. Cytokines (IL-1 beta, IL-6, IL-8, IL-10, IL-12p70 and TNF alpha) were analyzed by flow cytometry from serum samples collected within 50 minutes of race completion. Cardiac troponin (cTnI) and B-type natriuretic peptide were combined with an echocardiographic assessment of cardiac function, and a composite of cTnI > 0.04 mu g/L, BNP increase > 10 ng/L and a decrease in right ventricular ejection (RVEF) > 10% were prospectively defined as evidence of myocardial dysfunction. Results Relative to baseline, IL-6 IL-8 and IL-10 increased 8.5-, 2.9-, and 7.1-fold, respectively, P<0.0001. Thirty-one (78%), 19 (48%) and 18 (45%) of the athletes met the pre-specified criteria for significant cTnI, BNP and RVEF changes, respectively. TNF alpha, IL-12p70 were univariate predictors of Delta RVEF and Delta BNP whilst none of the anti-inflammatory cytokines were significantly associated with these measures. Ten athletes (25%, all athletes competing in the endurance event of longest duration) met criteria for exercise-induced myocardial dysfunction. In these 10 athletes with myocardial dysfunction, as compared to those without, there was significantly greater post-race expression of the pro-inflammatory cytokines IL-12p70 (8.1 +/- 3.8pg/ml vs. 2.5 +/- 2.6pg/ml, P<0.0001) and TNF alpha (6.5 +/- 3.1pg/ml vs. 2.0 +/- 2.5pg/ml, P<0.0001). Conclusion Cardiac dysfunction following intense endurance exercise was associated with increased expression of pro-inflammatory cytokines. This does not prove a causal relationship but provides rationale for further investigations into whether inflammation mediates exercise-induced myocardial dysfunction.

Language

English

Source (journal)

PLoS ONE

Publication

2015

ISSN

1932-6203

DOI

10.1371/JOURNAL.PONE.0130031

Volume/pages

10 :6 (2015) , 15 p.