Objective: To investigate interleukin (IL)-6 and other inflammation markers in athletes with spinal cord injury (SCI) during a wheelchair marathon race.
Design: Nonrandomized study in an actual race.
Setting: The 28th Oita International Wheelchair Marathon Race, Japan.
Participants: Twenty-eight men with SCI between T7 and L2 (16 full-marathon racers, full-group; and 12 half-marathon racers, half-group).
Main outcome measures: Plasma IL-6, tumor necrosis factor (TNF)-α, and high-sensitivity C-reactive protein (hsCRP) were measured the day before, immediately after the race, and 2 hours after the race.
Results: Plasma IL-6 concentrations increased by 18.4-fold and by 9.4-fold (P < 0.05) in the full- and half-groups immediately after the race (P < 0.05), respectively, but returned to baseline at 2 hours of recovery. In contrast, plasma TNF-α and hsCRP did not change throughout the race in both groups. The fold change in plasma IL-6 immediately after the race relative to the prerace was significantly higher in the full-group than the half-group (P < 0.05). In both groups, plasma IL-6 immediately after the race did not correlate with the average wheelchair speed. Interestingly, plasma IL-6 and hsCRP before the race in the full-group, but not in half-group, correlated negatively with the average wheelchair speed (P < 0.05).
Conclusions: The study demonstrated that half- and full-marathon wheelchair races increased plasma IL-6, but not TNF-α and hsCRP. Furthermore, the top athletes of the full-group had low plasma IL-6 and hsCRP at baseline. Wheelchair marathon competition, especially full-marathon, and daily training seem to have beneficial effects on SCI through the plasma IL-6 response.