Cardiotrophin-1 and TNF-alpha circulating levels at rest and during cardiopulmonary exercise test in athletes and healthy individuals

Background: There is a growing body of evidence that physical training exerts its potential benefits on the individual health status by modulating the immune system and the whole body metabolism. A better knowledge of the physiologic immune response to exercise may help to understand the benefits of physical exercise in healthy individuals and elite athletes. Aims: This study aims to analyse cardiotrophin-1 (CT-1) and Tumor Necrosis Factor-α (TNF-α) plasma levels at rest and during exercise in elite athletes and healthy controls. Methods: We studied 20 triathletes (TA) and 20 matched controls (CG). Chambers dimensions, left ventricular mass and left ventricular mass index were analysed by echocardiography. VO2 peak and VE/VCO2 were calculated by metabolic stress test. Blood samples were collected before the exercise session, at the exercise peak, and after the end of exercise. ELISA assays were used to measure CT-1 and TNF-α plasma levels. Results:Among TA and CG, no significant differences were found for CT-1 (0.25 ± 0.14 vs 0.20 ± 0.14 fm/l; p= 0.29) and TNF-α (10.8 ± 2.7 vs 9.7 ± 4.0 pm/l; p= 0.29) basal levels. In the TA, plasma levels of CT-1 were significantly different at rest and during exercise (basal 0.25 ± 0.13. pm/l; peak 1.07 ± 1.5. pm/l; post-exercise 0.67 ± 0.77. pm/l; p=0.04). Conversely, no significant differences were found between basal, peak and post-exercise plasma values of TNF-α (basal 10.8 ± 2.7. pm/l; peak 11.7 ± 2.1. pm/l; post-exercise 11.4 ± 2.5. pm/l; p=0.78) in TA. Conclusions: This study gives novel insights on the behavior of inflammatory cytokines during physical exercise in athletes and healthy individuals.