Iron metabolism regulation in females and males exposed to simulated microgravity: results from the randomized trial Artificial Gravity Bed Rest-European Space Agency (AGBRESA).
disuse
inflammation
metals
spaceflight
trace elements
Journal
The American journal of clinical nutrition
ISSN: 1938-3207
Titre abrégé: Am J Clin Nutr
Pays: United States
ID NLM: 0376027
Informations de publication
Date de publication:
11 2022
11 2022
Historique:
received:
07
01
2022
revised:
23
03
2022
accepted:
14
08
2022
medline:
24
5
2023
pubmed:
27
8
2022
entrez:
26
8
2022
Statut:
ppublish
Résumé
Iron metabolism imbalance could contribute to physical deconditioning experienced by astronauts due to its essential role in energy metabolism, cellular respiration, and oxygen transport. In this clinical exploratory study, we wanted to determine whether artificial gravity (AG) training modulated iron metabolism, RBC indices, and body lean mass in healthy male and female participants exposed to head-down tilt (HDT) bed rest, the reference ground-based model of microgravity. We recruited 8 healthy female and 16 healthy male participants who were all exposed to HDT bed rest for 60 d. In addition, they were assigned to 3 experimental groups (n = 8/each): controls, continuous AG training in a short-arm centrifuge (1 × 30 min/d), and intermittent AG training (6 × 5 min/d). The iron metabolism responses to simulated microgravity of the AG training groups did not differ significantly from the responses of controls. Independently from AG, we found that both serum iron concentrations (+31.3%, P = 0.027) and transferrin saturation levels (+28.4%, P = 0.009) increased in males after 6 d of HDT bed rest, as well as serum hepcidin concentrations (+36.9%, P = 0.005). The increase of transferrin saturation levels persisted after 57 d of HDT bed rest (+13.5%, P = 0.026), suggesting that long-term exposure to microgravity sustainably increases serum iron availability in males, and consequently the risk of iron excess or misdistribution. In females, 6 and 57 d of HDT bed rest did not significantly change serum iron, transferrin saturation, or hepcidin levels. The data from this exploratory study suggest that 1) AG training does not influence the iron metabolism responses to microgravity; and 2) iron metabolism parameters, especially iron availability for cells, are significantly increased in males, but not in females, exposed to long-term simulated microgravity. Because of the small sample size of females, we nevertheless must be cautious before concluding that iron metabolism could differently respond to microgravity in females. This trial was registered at https://www.drks.de as DRKS00015677.
Sections du résumé
BACKGROUND
Iron metabolism imbalance could contribute to physical deconditioning experienced by astronauts due to its essential role in energy metabolism, cellular respiration, and oxygen transport.
OBJECTIVES
In this clinical exploratory study, we wanted to determine whether artificial gravity (AG) training modulated iron metabolism, RBC indices, and body lean mass in healthy male and female participants exposed to head-down tilt (HDT) bed rest, the reference ground-based model of microgravity.
METHODS
We recruited 8 healthy female and 16 healthy male participants who were all exposed to HDT bed rest for 60 d. In addition, they were assigned to 3 experimental groups (n = 8/each): controls, continuous AG training in a short-arm centrifuge (1 × 30 min/d), and intermittent AG training (6 × 5 min/d).
RESULTS
The iron metabolism responses to simulated microgravity of the AG training groups did not differ significantly from the responses of controls. Independently from AG, we found that both serum iron concentrations (+31.3%, P = 0.027) and transferrin saturation levels (+28.4%, P = 0.009) increased in males after 6 d of HDT bed rest, as well as serum hepcidin concentrations (+36.9%, P = 0.005). The increase of transferrin saturation levels persisted after 57 d of HDT bed rest (+13.5%, P = 0.026), suggesting that long-term exposure to microgravity sustainably increases serum iron availability in males, and consequently the risk of iron excess or misdistribution. In females, 6 and 57 d of HDT bed rest did not significantly change serum iron, transferrin saturation, or hepcidin levels.
CONCLUSIONS
The data from this exploratory study suggest that 1) AG training does not influence the iron metabolism responses to microgravity; and 2) iron metabolism parameters, especially iron availability for cells, are significantly increased in males, but not in females, exposed to long-term simulated microgravity. Because of the small sample size of females, we nevertheless must be cautious before concluding that iron metabolism could differently respond to microgravity in females. This trial was registered at https://www.drks.de as DRKS00015677.
Identifiants
pubmed: 36026525
pii: S0002-9165(23)03667-5
doi: 10.1093/ajcn/nqac205
pii:
doi:
Substances chimiques
Hepcidins
0
Iron
E1UOL152H7
Transferrins
0
Types de publication
Randomized Controlled Trial
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
1430-1440Commentaires et corrections
Type : ErratumIn
Informations de copyright
Copyright © 2022 American Society for Nutrition.