A systemic review recently published in Multiple Sclerosis and Related Disorders revealed that only a small pool of research had examined the effect of routine physical activity on cytokine and adipokine profiles in the pathophysiology of multiple sclerosis (MS). Study researchers also reported that research on cytokines is in its infancy and future studies are essential to clarify the role exercise plays for people with MS.
Given the major role cytokines and adipokines play in the pathophysiology of MS, study investigators designed a comprehensive review of the “effect of regular physical activity on cytokine and adipokine expression in MS.” Researchers examined relevant human studies (randomized controlled trials and clinical trials) published before October 2017. Studies used in the review were obtained through searches of PubMed, the Cochrane Library, EMBASE, and PEDro.
Of the 907 possible studies, reviewers identified 12 that focused on cytokines, adipokines, MS, and physical activity. Most of the studies (10) examined exercise training and cytokines, 1 examined adipokines, and 1 study examined both cytokines and adipokines. Eight of the 12 studies assayed the IL-6 cytokine. There were no significant results associated with changing the IL-6 concentration and the efficacy of exercise training in 7 of the 8 studies. However, 1 study reported a reduction in the IL-6 concentration. Study investigators found that the effect of physical activity and exercise on cytokines is currently inconclusive in populations with MS.
Study limitations include a lack of generalizability due to small sample sizes and heterogeneous sampling. It is also likely that valuable studies were not included due to the use of only 4 databases and excluding data from cross-over design and cohort studies.
The study authors note that “[the] lack of systematic changes in cytokines and adipokines indicates that an anti-inflammatory effect of exercise is not the main underlying mechanism that mediates positive effects of exercise on outcomes such as [expanded disability status scale results], fatigue and other clinical outcomes following a short-term training period (less than 6 months) in persons with MS.” Although research indicates the importance of having an active lifestyle and its role in MS treatment, the study authors note “evidence does not support the notion that the potential disease modifying effect of exercise in MS should be driven by underlying changes in cytokines.”
Negaresh R, Motl RW, Mokhtarzade M, et al. Effects of exercise training on cytokines and adipokines in multiple sclerosis: A systematic review. Mult Scler Relat Disord. 2018; 24:91-100. doi: 10.1016/j.msard.2018.06.008.