Effect of Long-Term Physical Activity and Acute Exercise on Markers of Systemic Inflammation in Persons With Chronic Spinal Cord Injury: A Systematic Review

Abstract

ObjectiveTo evaluate the effect of long-term physical activity (PA) and acute exercise on markers of systemic inflammation in persons with chronic spinal cord injury (SCI). Data SourcesWe searched PubMed (MEDLINE), EMBASE, Central Register of Controlled Trials, CINAHL, and PEDro, involving variations of the Medical Subject Headings: SCI, PA, exercise, and inflammation. No time or language restrictions were applied. Study SelectionExcept for case reports, we included any type of study, both sexes, all ages, with SCI, resulting in the inclusion of 11 studies. PA included leisure or work activity, including exercise. Data ExtractionTwo authors independently scanned titles and abstracts and read the articles included. One author extracted and the second double-checked the data. The methodological quality and evidence were rated by using the Cochrane Risk of Bias tool or the Newcastle-Ottawa Scale and the Grading of Recommendations Assessment, Development and Evaluation approach. Data SynthesisThe included studies had a high risk of bias and “very low” levels of evidence. Meta-analyses were performed (random-effects model or generic inverse variance method). The acute interleukin-6 (IL-6) response to exercise was the same for individuals with SCI and able-bodied individuals (P=.91); however, responses were higher in those with paraplegia than in those with tetraplegia (weighted mean difference, 1.19, P<.0001, and 0.25, P=.003, respectively). Compared with physically inactive people with SCI, physically active people with SCI had lower plasma C-reactive protein (CRP) levels (weighted mean difference, −0.38; P=.009). CRP concentrations were lower after the exercise intervention than before the exercise intervention (weighted mean difference, −2.76; P=.0001). ConclusionsPA and exercise may improve systemic markers of low-grade inflammation in those with SCI, particularly IL-6 and CRP. The change in IL-6 and CRP levels seems to be greater in those with paraplegia than in those with tetraplegia.