Background: Physical activity may lower the risk for coronary artery disease (CAD) by mitigating inflammation, which plays a key role in the pathophysiology of atherosclerosis. The purpose of this study was to determine the effect of aerobic exercise training on levels of pro- and anti-inflammatory cytokines, IL-1, IL-6, IL-10, INF-gamma, and C-reactive protein (CRP), in CAD patients participating in a cardiac rehabilitation program.
Methods and results: Twenty-eight patients, age 64+/-7.1 years, participated in a 12-week aerobic exercise training program at 70-80% of individual maximal heart rate. Training resulted in a significant reduction of all pro-inflammatory cytokines, CRP from 7.5+/-4.2 to 3.9+/-3.5 mg/l, p<0.001, IL-1, 0.33+/-0.23 to 0.51+/-0.12 pg/ml, p=0.014, IL-6, 2.50+/-1.50 to 1.44+/-0.57 pg/ml, p=0.002, INF-gamma, 18.63+/-3.31 to 16.77+/-2.49 pg/ml, p<0.001, as well as a significant increase in the anti-inflammatory, cytokine IL-10, from 1.61+/-1.40 to 2.29+/-2.01 pg/ml, p=0.008. Baseline CRP levels were 36% (p=0.006) higher among diabetes mellitus patients and training was associated with a 40.5% CRP reduction in these patients compared to 19% reduction in non-diabetics, p<0.01. At baseline 72% of patients were in a high risk category (CRP>3 mg/l), 28% in an intermediate (CRP=1-3 mg/l), with none in a low risk category (<1 mg/l). Following exercise training, 11% were in the low risk, 50% in the intermediate and 39% in the high risk category, indicating 46% reduction in the number of subjects in the high risk category.
Conclusions: Aerobic exercise training in CAD patients is an effective mean in inducing reduction in CRP, IL-1, IL-6, INF-gamma levels, and increase in IL-10, thus, possibly improving coronary risk profile.