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Antioxidant supplementation does not attenuate oxidative stress at high altitude.
Aviat Space Environ Med. 2004 Oct; 75(10):881-8.AS

Abstract

INTRODUCTION

Hypobaric hypoxia and heightened metabolic rate increase free radical production.

PURPOSE

We tested the hypothesis that antioxidant supplementation would reduce oxidative stress associated with increased energy expenditure (negative energy balance) at high altitude (HA 4300 m).

METHODS

For 12 d at sea level (SL), 18 active men were fed a weight-stabilizing diet. Testing included fasting blood and 24-h urine samples to assess antioxidant status [plasma alpha-tocopherol, beta-carotene, lipid hydroperoxides (LPO), and urinary 8-hydroxydeoxyguanosine (8-OHdG)] and a prolonged submaximal (55% Vo2peak) oxidative stress index test (OSI) to evaluate exercise-induced oxidative stress (plasma LPO, whole blood reduced and oxidized glutathione, glutathione peroxidase, and urinary 8-OHdG). Subjects were then matched and randomly assigned to either a placebo or antioxidant supplement group for a double-blinded trial. Supplementation (20,000 IU of beta-carotene, 400 IU alpha-tocopherol acetate, 500 mg ascorbic acid, 100 microg selenium, and 30 mg zinc, or placebo) was begun 3 wk prior to and throughout a 14-d HA intervention. At HA, subjects' daily energy intake and expenditure were adjusted to achieve a caloric deficit of approximately 1400 kcal. Fasting blood and 24-h urine samples were collected throughout HA and the OSI test was repeated on HA day 1 and day 13.

RESULTS

Resting LPO concentrations increased and urinary 8-OHdG concentrations decreased over HA with no effect of supplementation. Prolonged submaximal exercise was not associated with increased concentrations of oxidative stress markers at SL or HA.

CONCLUSIONS

Antioxidant supplementation did not significantly affect markers of oxidative stress associated with increased energy expenditure at HA.

Authors+Show Affiliations

VA Palo Alto Health Care System, 3801 Miranda Ave., Palo Alto, CA 94304-1290, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Journal Article
Randomized Controlled Trial
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

15497369

Citation

Subudhi, Andrew W., et al. "Antioxidant Supplementation Does Not Attenuate Oxidative Stress at High Altitude." Aviation, Space, and Environmental Medicine, vol. 75, no. 10, 2004, pp. 881-8.
Subudhi AW, Jacobs KA, Hagobian TA, et al. Antioxidant supplementation does not attenuate oxidative stress at high altitude. Aviat Space Environ Med. 2004;75(10):881-8.
Subudhi, A. W., Jacobs, K. A., Hagobian, T. A., Fattor, J. A., Fulco, C. S., Muza, S. R., Rock, P. B., Hoffman, A. R., Cymerman, A., & Friedlander, A. L. (2004). Antioxidant supplementation does not attenuate oxidative stress at high altitude. Aviation, Space, and Environmental Medicine, 75(10), 881-8.
Subudhi AW, et al. Antioxidant Supplementation Does Not Attenuate Oxidative Stress at High Altitude. Aviat Space Environ Med. 2004;75(10):881-8. PubMed PMID: 15497369.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Antioxidant supplementation does not attenuate oxidative stress at high altitude. AU - Subudhi,Andrew W, AU - Jacobs,Kevin A, AU - Hagobian,Todd A, AU - Fattor,Jill A, AU - Fulco,Charles S, AU - Muza,Stephen R, AU - Rock,Paul B, AU - Hoffman,Andrew R, AU - Cymerman,Allen, AU - Friedlander,Anne L, PY - 2004/10/23/pubmed PY - 2004/12/23/medline PY - 2004/10/23/entrez SP - 881 EP - 8 JF - Aviation, space, and environmental medicine JO - Aviat Space Environ Med VL - 75 IS - 10 N2 - INTRODUCTION: Hypobaric hypoxia and heightened metabolic rate increase free radical production. PURPOSE: We tested the hypothesis that antioxidant supplementation would reduce oxidative stress associated with increased energy expenditure (negative energy balance) at high altitude (HA 4300 m). METHODS: For 12 d at sea level (SL), 18 active men were fed a weight-stabilizing diet. Testing included fasting blood and 24-h urine samples to assess antioxidant status [plasma alpha-tocopherol, beta-carotene, lipid hydroperoxides (LPO), and urinary 8-hydroxydeoxyguanosine (8-OHdG)] and a prolonged submaximal (55% Vo2peak) oxidative stress index test (OSI) to evaluate exercise-induced oxidative stress (plasma LPO, whole blood reduced and oxidized glutathione, glutathione peroxidase, and urinary 8-OHdG). Subjects were then matched and randomly assigned to either a placebo or antioxidant supplement group for a double-blinded trial. Supplementation (20,000 IU of beta-carotene, 400 IU alpha-tocopherol acetate, 500 mg ascorbic acid, 100 microg selenium, and 30 mg zinc, or placebo) was begun 3 wk prior to and throughout a 14-d HA intervention. At HA, subjects' daily energy intake and expenditure were adjusted to achieve a caloric deficit of approximately 1400 kcal. Fasting blood and 24-h urine samples were collected throughout HA and the OSI test was repeated on HA day 1 and day 13. RESULTS: Resting LPO concentrations increased and urinary 8-OHdG concentrations decreased over HA with no effect of supplementation. Prolonged submaximal exercise was not associated with increased concentrations of oxidative stress markers at SL or HA. CONCLUSIONS: Antioxidant supplementation did not significantly affect markers of oxidative stress associated with increased energy expenditure at HA. SN - 0095-6562 UR - https://www.unboundmedicine.com/medline/citation/15497369/Antioxidant_supplementation_does_not_attenuate_oxidative_stress_at_high_altitude_ L2 - https://www.ingentaconnect.com/openurl?genre=article&issn=0095-6562&volume=75&issue=10&spage=881&aulast=Subudhi DB - PRIME DP - Unbound Medicine ER -