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 first-ever 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-α and IL-1β 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 (β = 0.585, 95% CI = 0.164–1.006, p = 0.0073), IL-8 (β = 0.160, 95% CI = 0.004–0.317, p = 0.0447), and TNF-α (β = 0.0845, 95% CI = 0.0137–0.1553, p = 0.0206). The SC group also showed greater increases in CRP (β = 0.250, 95% CI = −0.407, 0.906, p = 0.4499) and IL-10 (β = 0.251, 95% CI = −0.024, 0.527, p = 0.0729) but group differences were not significant. IL-1β levels remained stable and differences between groups were not significant (β = −0.008, 95% CI = −0.058, 0.042, p = 0.7618). Conclusions: When introduced in the early subacute phase of stroke recovery, moderate-to-vigorous 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 long-term recovery and stroke recurrence needs to be determined.