Physical Training Increases Erythroferrone Levels in Men

SIMPLE SUMMARY: Intense physical activity contributes to an increased consumption of oxygen transported by red blood cells. The red blood cells’ differentiation and proliferation process is mainly stimulated by erythropoietin (EPO) and erythroferrone (ERFE), which are novel markers of erythroid activity. The purpose of this study was to assess the level of concentration of these hormones in athletes’ blood. Seventy-three clinically healthy men took part in this study. Participants were divided into groups according to their physical activity, as assessed by the questionnaire survey. The first group included 39 athletes, the second group included 18 men with moderate physical activity, and the third—16 men with a sedentary lifestyle. Men with a high level of weekly physical activity had significantly different concentrations of ERFE and EPO than men with insufficient weekly physical activity. Higher endogenic ERFE and EPO levels are indicators of increased erythropoiesis in the period of intensified physical activity. The results obtained suggest the important role of endogenic EPO in the process of adaptation to intense physical activity. ABSTRACT: Intense physical activity contributes to an increased demand for red blood cells, which transport oxygen to working muscles. The purpose of this study was to assess the concentration of erythroferrone (ERFE), the novel marker of erythroid activity in athletes, during the beginning of their training season. The study group consisted of 39 athletes aged 23.24 ± 3.77 years. The study was carried out during the athletes’ preparatory period of the training cycle. The control group consisted of 34 healthy men aged 22.33 ± 2.77 years. The erythropoietic activity was evaluated by determining athletes’ concentrations of erythropoietin (EPO) and erythroferrone (ERFE). The level of physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). In the athletes’ group, we observed higher concentrations of EPO (Me = 12.65 mIU/mL) and ERFE (40.00 pg/mL) compared to the control group (EPO: Me = 5.74 mIU/ml, p = 0.001; ERFE: Me = 25.50 pg/mL, p = 0.0034). The average intensity of physical exercise significantly differentiated the participants as far as EPO and ERFE concentrations. These results suggest that intense physical activity, at least at the beginning of the training season, may stimulate EPO production, which increases ERFE release. This seems to be an adaptative mechanism that provides adequate iron for enhanced erythropoiesis.