Urinary hepcidin, inflammation, and iron metabolism were examined during the 24 hr after exercise. Eight moderately trained athletes (6 men, 2 women) completed a 60-min running trial (15-min warm-up at 75–80% HRpeak + 45 min at 85–90% HRpeak) and a 60-min trial of seated rest in a randomized, crossover design. Venous blood and urine samples were collected pretrial, immediately posttrial, and at 3, 6, and 24 hr posttrial. Samples were analyzed for interleukin-6 (IL-6), C-reactive protein (CRP), serum iron, serum ferritin, and urinary hepcidin. The immediate postrun levels of IL-6 and 24-hr postrun levels of CRP were significantly increased from baseline (6.9 and 2.6 times greater, respectively) and when compared with the rest trial (p ≤ .05). Hepcidin levels in the run trial after 3, 6, and 24 hr of recovery were significantly greater (1.7–3.1 times) than the pre- and immediate postrun levels (p ≤ .05). This outcome was consistent in all participants, despite marked variation in the magnitude of rise. In addition, the 3-hr postrun levels of hepcidin were significantly greater than at 3 hr in the rest trial (3.0 times greater, p ≤ .05). Hepcidin levels continued to increase at 6 hr postrun but failed to significantly differ from the rest trial (p = .071), possibly because of diurnal influence. Finally, serum iron levels were significantly increased immediately postrun (1.3 times, p ≤ .05). The authors concluded that high-intensity exercise was responsible for a significant increase in hepcidin levels subsequent to a significant increase in IL-6 and serum iron.
Peter Peeling, Brian Dawson, Carmel Goodman, Grant Landers, Erwin T. Wiegerinck, Dorine W. Swinkels and Debbie Trinder
Mia K. Newlin, Sara Williams, Tim McNamara, Harold Tjalsma, Dorine W. Swinkels and Emily M. Haymes
To investigate the effects of acute exercise on serum hepcidin and iron (sFe) in active women. Changes in interleukin-6 (IL-6), hepcidin, ferritin, and sFe in response to 2 different exercise durations were compared.
Twelve women age 19–32 yr performed 2 treadmill runs (60 and 120 min) at 65% of VO2max. Blood samples were obtained before, immediately after, and 3, 6, 9, and 24 hr after exercise. Two-way repeatedmeasures ANOVA was conducted to examine changes in measured variables. Significance was accepted at p < .05.
Significant effects for trial were observed for hepcidin (60 min: 1.15 ± 0.48 nmol/L; 120 min: 2.28 ± 1.44 nmol/L) and for time, with hepcidin significantly increased 3 hr postexercise in both trials (60 min: 3 hr – 1.99 ± 2.00 nmol/L; 120 min: 3 hr – 4.60 ± 4.61 nmol/L). Significant main effects for time occurred for sFe, ferritin, and IL-6. sFe was significantly decreased 9 hr postexercise compared with 3 and 24 hr postexercise. IL-6 was significantly increased immediately postexercise.
Both runs resulted in significant increases in hepcidin 3 hr after exercise. Increases in hepcidin were preceded by significant increases in IL-6 immediately postexercise and followed by significant decreases in sFe 9 hr postexercise. It was concluded that endurance exercise increases the production of hepcidin, which affects sFe. The 2-hr exercise bout stimulated greater changes in serum hepcidin than the 1-hr bout.
Marc Sim, Brian Dawson, Grant Landers, Dorine W. Swinkels, Harold Tjalsma, Debbie Trinder and Peter Peeling
The effect of exercise modality and intensity on Interleukin-6 (IL-6), iron status, and hepcidin levels was investigated. Ten trained male triathletes performed 4 exercise trials including low-intensity continuous running (L-R), low-intensity continuous cycling (L-C), high-intensity interval running (H-R), and high-intensity interval cycling (H-C). Both L-R and L-C consisted of 40 min continuous exercise performed at 65% of peak running velocity (vVO2peak) and cycling power output (pVO2peak), while H-R and H-C consisted of 8 × 3-min intervals performed at 85% vVO2peak and pVO2peak. Venous blood samples were drawn pre-, post-, and 3 hr postexercise. Significant increases in postexercise IL-6 were seen within each trial (p < .05) and were significantly greater in H-R than L-R (p < .05). Hepcidin levels were significantly elevated at 3 hr postexercise within each trial (p < .05). Serum iron levels were significantly elevated (p < .05) immediately postexercise in all trials except L-C. These results suggest that, regardless of exercise mode or intensity, postexercise increases in IL-6 may be expected, likely influencing a subsequent elevation in hepcidin. Regardless, the lack of change in postexercise serum iron levels in L-C may indicate that reduced hemolysis occurs during weight-supported, low-intensity activity.