Daily regulation of serum and urinary hepcidin is not influenced by submaximal cycling exercise in humans with normal iron metabolism

Abstract

Hepcidin and hemojuvelin (HJV) are two critical regulators of iron metabolism as indicated by the development of major iron overload associated to mutations in hepcidin and HJV genes. Hepcidin and HJV are highly expressed in liver and muscles, respectively. Intensive muscular exercise has been reported to modify serum iron parameters and to increase hepcidinuria. The present study aimed at evaluating the potential impact of low intensity muscle exercise on iron metabolism and on hepcidin, its key regulator. Fourteen normal volunteers underwent submaximal cycling-based exercise in a crossover design and various iron parameters, including serum and urinary hepcidin, were serially studied. The results demonstrated that submaximal ergocycle endurance exercise did not modulate hepcidin. This study also indicated that hepcidinuria did not show any daily variation whereas serum hepcidin did. The findings, by demonstrating that hepcidin concentrations are not influenced by submaximal cycling exercise, may have implications for hepcidin sampling in medical practice.

Joint Model of Iron and Hepcidin During the Menstrual Cycle in Healthy Women

“…Hepdicin has attracted interest as a major player in the regulation of iron metabolism, and since the development of an analytical method to measure its serum concentration, it is being introduced in the array of diagnostic tools for iron disorders (7). Little is known however about the withinsubject variations to be expected, in particular in women: significant diurnal variations of hepcidin have been reported (29), and gender, as well as age, has been shown to impact the values of hepcidin concentrations in normal subjects (10,30,31). In addition, the evolution of martial settings including serum iron shows significant variations during the menstrual cycle (9).…”

Exercise as a mediator of hepcidin activity in athletes

“…Additionally, recent research has also shown that cycling (a nonweight-bearing activity) may not have the same impact on the hepcidin response as has been seen in the aforementioned running investigations (Troadec et al 2009). In this study, Troadec et al had 14 untrained male participants, aged 18-40 years, with a healthy iron status complete two experimental trials in a randomized, crossover fashion.…”

“…However, Fischer (2006 suggests that eccentric exercise is not associated with a more marked increase in plasma IL-6 levels when compared with concentric muscle contractions, and that it is the combination of exercise intensity and duration that determines the magnitude of the increase in plasma IL-6. As such, it may be that the intensity and duration of exercise chosen by Troadec et al (2009) was not of sufficient magnitude to produce a significant inflammatory and subsequent hepcidin response.…”

“…A degradation of the Fpn transporters can result in decreased dietary iron absorption from the small intestine and a reduction in the ability to recycle iron from the macrophage (Ganz 2003). Due to the nature of this inflammatory regulation, recent research (Table 1) has focused on the influence of exercise on the activity of this hormone, with the aim of exploring a new mechanism to explain athletics-induced iron deficiency (Peeling et al 2009a, b, c;Roecker et al 2005;Troadec et al 2009). …”

“…The potential of this mechanism to explain such a nutritional disorder commonly suffered by athletes has sparked new research attempting to explore the post-exercise kinetics of hepcidin and its impact on iron metabolism (Peeling et al 2009a, b, c;Roecker et al 2005;Troadec et al 2009). The general outcomes of this research have shown that hepcidin levels appear elevated during 24 h after exercise, subsequent to significant acute elevations in serum iron and inflammation.…”