Influence of normobaric hypoxic exercise on endothelial progenitor cell senescence by in vitro cultivation with conditioned media

Objective: Circulating endothelial progenitor cells (EPCs) were shown to be affected in cardiovascular and metabolic diseases. As interventional strategies, hypoxia and exercise are both known to increase the number and enhance the function of EPCs, potentially by extending their lifespan induced by a reduced senescence. Therefore, this pilot study investigated the effect of exercise under normobaric hypoxia on the senescence of EPCs by in vitro cultivation with autologous human serum (AHS). Methods: Four healthy trained young males (23 {+/-} 2 years) performed an incremental cycling step test until exhaustion in a normobaric hypoxic-chamber with an average altitude of 4,000 m (O2 12.3%). Blood serum was taken at pre, 10 min post and 4 h post, which was later used for in vitro cultivation of EPCs. Senescence was investigated by {beta}-galactosidase staining. Results: The participants spent 30-40 min in normobaric hypoxia. The EPC senescence rate was reduced 10 min (0.72 {+/-} 0.57%) and 4 hours (0.67 {+/-} 0.52%) after exercise compared to pre (1.89 {+/-} 0.37%). Conclusion: This pilot study indicates that intense exercise under normobaric hypoxia may enhance EPC function by slowing down their senescence.