Ferritin status impact on hepcidin response to endurance exercise in physically active women along different phases of the menstrual cycle

Abstract

Serum ferritin has been proposed as a predictor of hepcidin concentrations in response to exercise. However, this fact has not been studied in physically-active women. Therefore, the main objective of this study was to analyse the hepcidin response at different ferritin status before and after running exercise in physically active females. Fifteen eumenorrheic women performed a 40-min running protocol at 75% of VO2peak speed in different menstrual cycle phases (early-follicular phase, mid-follicular phase and luteal phase). Blood samples were collected pre-exercise, 0h post-exercise and 3h post-exercise. For statistics, participants were divided into two groups according to their pre-exercise ferritin levels (<20 and ≥20 μg/L). Through menstrual cycle, hepcidin was lower in both early follicular phase (p=0.024; 64.81±22.48 ng/ml) and mid-follicular phase (p=0.007; 64.68±23.91 ng/ml) for <20 μg/L ferritin group, in comparison with ≥20 μg/L group (81.17±27.89 and 79.54±22.72 ng/ml, respectively). Hepcidin showed no differences between both ferritin groups in either pre-exercise, 0h post-exercise and 3h post-exercise. Additionally, no association between pre-exercise ferritin and hepcidin levels 3h post-exercise (r=-0.091; p=0.554) was found. Menstrual cycle phase appears to influence hepcidin levels depending on ferritin reserves. In particular, physically-active females with depleted ferritin reserves seems to present lower hepcidin levels during the early-follicular phase and mid-follicular phase. However, no association between ferritin and hepcidin levels was found in this study. Hence, ferritin levels alone may not be a good predictor of hepcidin response to exercise in this population. Multiple factors such as sexual hormones, training loads and menstrual bleeding must be taken into account.