Effects of acute exercise on inflammatory and metabolic biomarkers in women: a randomized controlled trial

Mechanisms linking exercise to reduced breast cancer risk are poorly understood. 103 healthy women, 18-75, were randomized to 45-minutes of acute exercise at 60% VO₂max (N = 54, intervention), or 45-minutes of rest (N = 49, control). Blood samples were collected at baseline, 45- and 105-minutes, analytes measured by immunoassay, and mean changes from baseline to 45- and 105-minutes modelled using generalized estimating equations, adjusted for confounders. Mean percent changes levels (Δ%) increased in exercisers vs. controls for monocyte chemoattractant protein (MCP)-1 Δ^{45 min} + 17.1% (P < 0.0001), Δ^{105 min} + 12.0% (P = 0.005); interleukin(IL)-6, Δ^{45 min} + 103.5%, Δ^{105 min} + 92.3%; and at 45-minutes for glucose Δ^{45 min} + 8.8%; insulin Δ^{45 min} + 82.4% (all P < 0.0001). Differences between arms for vascular endothelial growth factor (VEGF) Δ^{45 min} + 9.8%; c-reactive protein Δ^{45 min}-6.6%; irisin Δ^{45 min}-5.1%; or plasminogen activator inhibitor (PAI)-1, Δ^{45 min}-3.6% were non-statistically significant, with similar results at 105-minutes. Results suggest that acute exercise has specific effects on circulating metabolic and inflammatory biomarkers, implicated in breast cancer etiology, which differ from weight-loss-induced changes. Trial registration: Clincialtrials.gov identifier NCT03779867.