Is The Inflammatory Responses During And After 7-day Marathon A Good Model For Sepsis Mechanism?

Abstract

Purposes: To evaluate changes of the immune system in athletes during and after 7- day marathon and to correlate these changes with mechanism of clinical sepsis. METHODS: The subjects were nine healthy athletes (5 males and 4 females, age 52.4±2.5 yr; means±SEM) in 7-day race of the 2008 Athens ultra-marathon festival. Blood samples were collected before, during and after the competition. The concentrations of plasma cortisol, neutrophil degranulation (total elastase release), and total white blood cell (WBC) and differential WBC counts including lymphocytes, neutrophils and monoocytes were measured. RESULTS: (1) Comparing to pre-race, total WBC counts, lymphocyte counts and monocyte counts of subjects significantly decreased (-6.7%∼-33.6%, -61.7%∼-72.7%, -3.1%∼-63% respectively, P<.05) during the race. Contrarily, neutrophil counts, total elastase release and the concentration of plasma cortisol significantly increased (-3.1%∼43.5%, 21.7%∼119.8%, 288.3%∼387.3% respectively, P<.05) (2) Total WBC counts, neutrophil counts and total elastase release during the race were less than post-race (P<.05) while lymphocyte counts slightly recovered after the race. (3) Total WBC counts, neutrophil counts, lymphocyte counts and monocyte counts during post-race were less than pre-race (P<.05) while the concentration of plasma cortisol was still higher than pre-race concentration (P<.05). CONCLUSIONS: The main findings of this study were (1) acute inflammatory response in runners occurred in the first day of 7-day race, including increased neutrophil counts and total elastase release, which may be due to heavy stress of ultra-marathon; (2) immunosuppression induced by prolong exercise and presented as the decrement of total and differential white blood cell counts, may not fully recover during 2 days post-race; (3) the inflammatory responses pattern of the immune system in the 7-day marathon runners is similar to the developing of sepsis.