Cytokine Response at High Altitude: Effects of Exercise and Antioxidants at 4300 m

Todd A. Hagobian, Veterans Afrairs Palo Alto Health Care System, Palo Alto, CA
Kevin A. Jacobs, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA
Andrew W. Subudhi, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA
Jill A. Fattor, University of California - Berkeley
Paul B. Rock, Oklahoma State University Center for Health Sciences
Stephen R. Muza, US Army Research Institute of Environmental Medicine, Natick, MA
Charles S. Fulco, US Army Research Institute of Environmental Medicine, Natick, MA
Barry Braun, University of Massachusetts - Amherst
Ann Grediagin, US Army Research Institute of Environmental Medicine, Natick, MA
Robert S. Mazzeo, University of Colorado at Boulder
Allen Cymerman, US Army Research Institute of Environmental Medicine, Natick, MA
Anne L. Friedlander, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA

Article comments

Copyright © 2006 American College of Sports Medicine. This is a non-final version of an article published in final form in Medicine and Science in Sports and Exercise. The definitive version is available at http://dx.doi.org/10.1249/01.mss.0000188577.63910.51.

NOTE: At the time of publication, the author Todd Hagobian was not yet affiliated with Cal Poly.

Abstract

Purpose: This study tested the hypothesis that antioxidant supplementation would attenuate plasma cytokine (IL-6, tumor necrosis factor (TNF)-α), and C-reactive protein (CRP) concentrations at rest and in response to exercise at 4300-m elevation.
Methods: A total of 17 recreationally trained men were matched and assigned to an antioxidant (N = 9) or placebo (N = 8) group in a double-blinded fashion. At sea level (SL), energy expenditure was controlled and subjects were weight stable. Then, 3 wk before and throughout high altitude (HA), an antioxidant supplement (10,000 IU β-carotene, 200 IU α-tocopherol acetate, 250 mg ascorbic acid, 50 2g selenium, 15 mg zinc) or placebo was given twice daily. At HA, energy expenditure increased approximately 750 kcald^-1 and energy intake decreased approximately 550 kcald^-1, resulting in a caloric deficit of approximately 1200–1500 kcald^-1. At SL and HA day 1 (HA1) and day HA13, subjects exercised at 55% of VO_2peak until they expended approximately 1500 kcal. Blood samples were taken at rest, end of exercise, and 2, 4, and 20 h after exercise.
Results: No differences were seen between groups in plasma IL-6, CRP, or TNF-! at rest or in response to exercise. For both groups, plasma IL-6 concentration was significantly higher at the end of exercise, 2, 4, and 20 h after exercise at HA1 compared with SL and HA13. Plasma CRP concentration was significantly elevated 20 h postexercise for both groups on HA1 compared to SL and HA13. TNF-α did not differ at rest or in response to exercise.
Conclusion: Plasma IL-6 and CRP concentrations were elevated following exercise at high altitude on day 1, and antioxidant supplementation did not attenuate the rise in plasma IL-6 and CRP concentrations associated with hypoxia, exercise, and caloric deficit.