Impact of aerobic exercise on levels of IL‐4 and IL‐10: results from two randomized intervention trials

摘要

The mechanisms whereby regular exercise reduces chronic inflammation remain unclear. We investigated whether regular aerobic exercise alters basal levels of interleukin (IL)‐10 and IL‐4 in two randomized trials of physical activity. The Alberta Physical Activity and Breast Cancer Prevention Trial (ALPHA, n = 320) and the Breast Cancer and Exercise Trial in Alberta (BETA, n = 400) were two‐center, two‐armed randomized trials in inactive, healthy, postmenopausal women. Both trials included an exercise intervention prescribed five times/week and no dietary changes. In ALPHA, the exercise group was prescribed 225 min/week versus no activity in the controls. BETA examined dose‐response effects comparing 300 (HIGH) versus 150 (MODERATE) min/week. Plasma concentrations of IL‐10 and IL‐4 were measured at baseline, 6, and 12 months. Intention‐to‐treat (ITT) analysis was performed using linear mixed models adjusted for baseline biomarker concentrations. Circulating anti‐inflammatory cytokine levels decreased among all groups, with percent change ranging from −3.4% (controls) to −8.2% (HIGH) for IL‐4 and −1.6% (controls) to −7.5% (HIGH) for IL‐10. No significant group differences were found for IL‐4 (ALPHA P = 0.54; BETA P = 0.32) or style="fixed-case">IL‐10 ( style="fixed-case">ALPHA P = 0.84; style="fixed-case">BETA P = 0.68). Some evidence for moderation of the effect of exercise by baseline characteristics was found for style="fixed-case">IL‐10 but not for style="fixed-case">IL‐4. Results from these two large randomized aerobic exercise intervention trials suggest that aerobic exercise does not alter style="fixed-case">IL‐10 or style="fixed-case">IL‐4 in a manner consistent with chronic disease and cancer prevention.