title: Effects of a 7-day military training exercise on inflammatory biomarkers, serum hepcidin, and iron status.
abstract: BACKGROUND
  Hepcidin, a peptide that is released into the blood in response to inflammation, prevents cellular iron export and results in declines in iron status. Elevated serum and urinary levels of hepcidin have been observed in athletes following exercise, and declines in iron status have been reported following prolonged periods of training. The objective of this observational study was to characterize the effects of an occupational task, military training, on iron status, inflammation, and serum hepcidin.
  
  
  RESULTS
  Volunteers (n = 21 males) included Norwegian Soldiers participating in a 7-day winter training exercise that culminated in a 3-day, 54 km ski march. Fasted blood samples were collected at baseline, on day 4 (PRE, prior to the ski march), and again on day 7 (POST, following the ski march). Samples were analyzed for hemoglobin, serum ferritin, soluble transferrin receptor (sTfR), interleukin-6 (IL-6), and serum hepcidin. Military training affected inflammation and serum hepcidin levels, as IL-6 and hepcidin concentrations increased (P < 0.05) from the baseline to POST (mean ± SD, 9.1 ± 4.9 vs. 14.5 ± 8.4 pg/mL and 6.5 ± 3.5 vs. 10.2 ± 6.9 ng/mL, respectively). Iron status was not affected by the training exercise, as sTfR levels did not change over the course of the 7-day study.
  
  
  CONCLUSIONS
  Military training resulted in significant elevations in IL-6 and serum hepcidin. Future studies should strive to identify the role of hepcidin in the adaptive response to exercise, as well as countermeasures for the prevention of chronic or repeated elevations in serum hepcidin due to exercise or sustained occupational tasks which may result in longer term decrements in iron status.
authors.forename: James P
authors.initials: JP
authors.lastname: McClung
authors.forename: Svein
authors.initials: S
authors.lastname: Martini
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Murphy
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Montain
authors.forename: Lee M
authors.initials: LM
authors.lastname: Margolis
authors.forename: Ingjerd
authors.initials: I
authors.lastname: Thrane
authors.forename: Marissa G
authors.initials: MG
authors.lastname: Spitz
authors.forename: Janet-Martha
authors.initials: JM
authors.lastname: Blatny
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Young
authors.forename: Yngvar
authors.initials: Y
authors.lastname: Gundersen
authors.affiliation: Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA. stefan.pasiakos@us.army.mil.
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Pasiakos
mesh_terms: D015415:Biomarkers / Q000097:blood*; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002149:Energy Intake; D015444:Exercise / Q000502:physiology*; D005293:Ferritins / Q000097:blood; D006454:Hemoglobins / Q000378:metabolism; D064451:Hepcidins / Q000097:blood*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D019266:Iron, Dietary / Q000097:blood*; D008297:Male; D008889:Military Personnel; D009664:Norway; D011990:Receptors, Transferrin / Q000097:blood; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D064451:Hepcidins; D015850:Interleukin-6; D019266:Iron, Dietary; D011990:Receptors, Transferrin; D005293:Ferritins