Elevation of interleukin-6 and attenuation of tumor necrosis factor-α during wheelchair half marathon in athletes with cervical spinal cord injuries

Study design: Nonrandomized study. Objectives: The purpose of this study was to determine the effects of long and intensive exercise on interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in athletes with cervical spinal cord injuries (CSCI). Setting: The 30th Oita International Wheelchair Marathon Race. Methods: Blood samples from six athletes with CSCI and eight athletes with thoracic and lumber spinal cord injuries (SCI) participating in wheelchair half marathon race were collected before the race, immediately after the race and 2 h after the race. IL-6, TNF-alpha, adrenaline and blood cell counts were measured. Results: Monocyte count remained stable throughout the study in the CSCI group but was significantly high at 2 h after the race in the SCI group. Plasma IL-6 concentrations were significantly elevated immediately after the race in both groups, although the levels in CSCI were significantly lower than in the SCI group. Plasma adrenaline was significantly elevated immediately after the race in the SCI group but recovered at 2 h after the race. In contrast, plasma adrenaline did not change in the CSCI group throughout the study and was significantly lower than in the SCI group. Plasma TNF-alpha did not change throughout the study in the SCI group compared with a significant decrease at 2 h after the race in the CSCI group. Conclusion: Long and intensive exercise increased IL-6 in the CSCI group despite the small muscle mass and lack of sympathetic nervous system. The post-race fall in plasma TNF-alpha in the CSCI group could be related to the inhibitory effect of rising IL-6 in the presence of normal monocyte count and stable adrenaline level.