Effect of 2‐h hypoxic exposure on resting hepcidin levels in young adults

We evaluated the effects of acute hypoxic exposure on serum hepcidin levels. In a crossover design, 11 healthy individuals (9 men and 2 women) completed a 2‐h period of seated rest in a hypoxic (HYP; fraction of inspired oxygen [FiO 2 ]: 12.5%) or normoxic control (CON; FiO 2 : 20.9%) environment in the morning. Following the environmental exposure, participants rested in a CON environment for 6 h. Venous blood samples were collected at baseline, immediately post‐exposure, and at 2‐, 4‐, and 6‐h post‐exposure. Serum erythropoietin (EPO) levels increased significantly over time in both conditions ( p < 0.05). At 2‐h post‐exposure, the EPO response was significantly greater in HYP than in CON ( p < 0.05). Serum erythroferrone (ERFE) levels did not differ significantly between the HYP and CON trials at any time point. Serum hepcidin levels increased significantly at 4‐ and 6‐h post‐exposure in both trials compared to baseline ( p < 0.05). However, no significant differences in serum hepcidin levels were observed between the HYP and CON trials at any time point. These findings suggest that a 2‐h hypoxic exposure enhances the erythropoietic response in young adults but does not suppress diurnal serum hepcidin or elevate ERFE levels.