The effects of acute aerobic exercise on mood and inflammation in individuals with multiple sclerosis and incomplete spinal cord injury

BACKGROUND: Spinal cord injury (SCI) and multiple sclerosis (MS) are associated with increased risks of depression. Acute exercise may improve mood in these populations via its affect on inflammation. OBJECTIVE: To determine if acute exercise can positively affect mood in individuals with SCI and MS, and whether exercise-induced changes in inflammation contribute to such improvements. METHODS: Thirteen participants completed 30 minutes of moderate-intensity exercise. Mood data (POMS questionnaire) and blood samples were taken before and after exercise, and blood was analyzed for inflammatory mediators and kynurenine pathway metabolites. RESULTS: There was a significant reduction in total mood disturbance (TMD) pre to post-exercise, and pre to one-hour post-exercise. There was a significant decrease in TNF-alpha from pre to post-exercise, with further reductions one-hour post-exercise. There were no correlations between changes in TMD and changes in inflammation. However, changes in certain cytokines showed significant or trending correlations with changes in subsets of the POMS. Likewise, there was a trend for a correlation between exercise-induced changes in KYN/TRP and depression (p = 0.096). CONCLUSIONS: Acute exercise can positively affect mood after SCI and MS, and this change may be partially accounted for by exercise-induced changes in inflammation. This relationship may be, in part, kynurenine pathway-dependent.