Cardiovascular exercise mitigates inflammation in the early subacute phase of stroke recovery: a secondary analysis of a randomized controlled trial

Background: Excessive inflammation in early phases post-ischemic stroke is associated with poor long-term outcome and increased stroke recurrence. Interventions capable of downregulating persistent states of inflammation could improve recovery and prevent secondary stroke. Cardiovascular exercise (CE) has well-established anti-inflammatory effects but its capacity to attenuate the exaggerated inflammatory response triggered by ischemic stroke is unclear. Methods: We investigated the impact of eight weeks of CE on the serum concentration of inflammatory mediators in the early subacute phase post-stroke. Seventy-one patients with firstever ischemic stroke were randomly assigned to moderate-to-vigorous CE (n=45) or standard care (SC) (n=26). Concentrations of CRP, IL-6, IL-8, IL-10, TNF- and IL-1{beta} were measured at baseline and after the interventions. Differences between groups were analyzed with linear mixed models adjusted for age and sex. Results: Compared with the CE group, the SC group showed significant increases in IL-6 ({beta}=0.585, 95% CI=0.164-1.006, p=0.0073), IL-8 ({beta}=0.160, 95% CI=0.004-0.317, p=0.0447), and TNF- ({beta}=0.0845, 95% CI=0.0137-0.1553, p=0.0206). The SC group also showed greater increases in CRP ({beta}=0.250, 95% CI=-0.407, 0.906, p=0.4499) and IL-10 ({beta}=0.251, 95% CI=-0.024, 0.527, p=0.0729) but group differences were not significant. IL-1{beta} levels remained stable and differences between groups were not significant ({beta}=-0.008, 95% CI=-0.058, 0.042, p=0.7618). Conclusions: When introduced in the early subacute phase of stroke recovery, moderate-tovigorous CE mitigates increases in inflammation, but the effect differs across mediators. To what extent reducing the inflammatory response in the early stages post-stroke with CE can impact longterm recovery and stroke recurrence needs to be determined.