Chronic inflammation and infection associate with a lower exercise training response in cystic fibrosis adolescents.

Considerable heterogeneity among training-induced effects is observed in patients with cystic fibrosis (CF). We previously showed that longitudinal changes in exercise capacity in adolescents with CF were negatively associated with Pseudomonas aeruginosa (P. aeruginosa) colonization and total immunoglobulin G (IgG) levels, independent of age, pulmonary function and bodyweight. This is the first study investigating whether chronic inflammation and infection also associate with the exercise training response in adolescents with CF. Participants performed a home-based exercise training program for 12 weeks. Pulmonary function, anthropometrics, exercise capacity, markers of inflammation and P. aeruginosa colonization status were measured at baseline. Exercise training-induced changes in pulmonary function and exercise capacity were compared between patients with a low and high inflammation-infection status. Participants with CF with high total IgG levels and P. aeruginosa colonization improved significantly less from the exercise training program, with regard to maximal oxygen consumption. These observations support the hypothesis that chronic systemic inflammation and infection leads to devastating effects on skeletal muscles, hampering skeletal muscle tissue to improve from regular physical exercise. Data further suggest that patients with CF should preferentially be encouraged to engage in regular physical exercise when inflammation and infection status is low (e.g. at a young age).

Effect of long-term voluntary exercise wheel running on susceptibility to bacterial pulmonary infections in a mouse model.

Regular moderate exercise has been suggested to exert anti-inflammatory effects and improve immune effector functions, resulting in reduced disease incidence and viral infection susceptibility. Whether regular exercise also affects bacterial infection susceptibility is unknown. The aim of this study was to investigate whether regular voluntary exercise wheel running prior to a pulmonary infection with bacteria (P. aeruginosa) affects lung bacteriology, sickness severity and phagocyte immune function in mice. Balb/c mice were randomly placed in a cage with or without a running wheel. After 28 days, mice were intranasally infected with P. aeruginosa. Our study showed that regular exercise resulted in a higher sickness severity score and bacterial (P. aeruginosa) loads in the lungs. The phagocytic capacity of monocytes and neutrophils from spleen and lungs was not affected. Although regular moderate exercise has many health benefits, healthy mice showed increased bacterial (P. aeruginosa) load and symptoms, after regular voluntary exercise, with perseverance of the phagocytic capacity of monocytes and neutrophils. Whether patients, suffering from bacterial infectious diseases, should be encouraged to engage in exercise and physical activities with caution requires further research.