Exercise and inflammation in coronary artery disease: A systematic review and meta-analysis of randomised trials

Current evidence suggests that chronic inflammation contributes to the development of coronary artery disease (CAD). Interestingly, exercise may constitute a method of reducing inflammation in this patient population. As such, this systematic review and meta-analysis examined the evidence generated by randomised studies that investigated the effect of exercise on inflammatory biomarkers in CAD. Literature was sought from various sources. Outcomes were pooled in a random-effects model to calculate standardised mean differences (SMD) with 95% confidence intervals (CI). Twenty-five studies were reviewed; post-intervention C-reactive protein (SMD: -0.55 (95% CI: -0.93, -0.16), P = 0.005), fibrinogen (SMD: -0.52 (95% CI: -0.74, -0.29, P = <0.00001)), and von Willebrand factor (SMD: -1.57 (95% CI: -2.23, -0.92), P = <0.00001) values were significantly lower in exercise groups compared to controls. In addition, qualitative analyses identified evidence that supports a beneficial effect of exercise on these acute-phase reactants. However, the impact of exercise on anti-inflammatory cytokines, adhesion molecules, and chemokines is equivocal, which may be attributed to a paucity of research. Nevertheless, the findings of this review suggest that exercise induces an anti-inflammatory effect in CAD patients. Although, the quality of evidence needs to be improved by further randomised studies with high methodological qualities and large sample sizes.