Systemic Inflammation, Vascular Function and Endothelial Progenitor Cells after an Exercise Training Intervention in COPD

Abstract Background Exercise training is a cornerstone of the treatment of COPD in all disease stages. Data about the training effects with supplemental oxygen in non-hypoxemic patients remains inconclusive. In this study we set out to investigate the training and oxygen effects on inflammatory markers, vascular function and endothelial progenitor cells in this population of increased cardiovascular risk. Methods In this prospective, randomized, double-blind, crossover study, 29 patients with non-hypoxemic COPD performed combined endurance and strength training three times a week while breathing medical air or supplemental oxygen for the first six-week period, to be then reallocated to the opposite gas for the following six weeks. Exercise capacity, inflammatory biomarkers, endothelial function (Peripheral Arterial Tone analysis) and endothelial progenitor cells were assessed. Data were also analyzed for a subgroup with endothelial dysfunction (Reactive Hyperemia Index (RHI) Results Following 12 weeks of exercise training, patients demonstrated a significant improvement of peak work rate and an associated decrease of blood fibrinogen and leptin. Eosinophils were found significantly reduced after exercise training in patients with endothelial dysfunction. In this subgroup, peripheral arterial tone analysis revealed a significant improvement of RHI. Generally, late endothelial progenitor cells were found significantly reduced after the exercise training intervention. Supplemental oxygen during training positively influenced the effect on exercise capacity without impact on inflammation and endothelial function. Conclusions This is the first randomized controlled trial in patients with COPD to show beneficial effects of exercise training not only on exercise capacity, but also on systemic/eosinophilic inflammation and endothelial dysfunction.