QJM Advance Access originally published online on March 9, 2009
QJM 2009 102(5):341-348; doi:10.1093/qjmed/hcp026
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Oral antioxidant supplementation does not prevent acute mountain sickness: double blind, randomized placebo-controlled trial
From the 1Department of Anaesthesia, Critical Care and Pain Medicine, University of Edinburgh, Edinburgh, 2Academic Unit of Respiratory Medicine, Royal Hallamshire Hospital, Sheffield, 3Department of Cardiology, Royal Infirmary of Edinburgh, Edinburgh, 4Department of Cardiology, University Hospital of North Durham, County Durham, 5Nuffield Department of Surgery, John Radcliffe Hospital, Oxford, 6ELEGI, COLT Research, MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, and 7Clinical Pharmacology Unit, Queen's Medical Research Institute, University of Edinburgh, Edinburgh
Address correspondence to Dr J.K. Baillie, Clinical Lecturer, Department of Anaesthesia, Critical Care and Pain Medicine, University of Edinburgh, Royal Infirmary of Edinburgh, 51 Little France Drive, Edinburgh EH16 5SA, UK. email: j.k.baillie{at}altitude.org
Received 11 November 2008 and in revised form 15 February 2009
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Abstract |
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Background: Acute mountain sickness may be caused by cerebrovascular fluid leakage due to oxidative damage to the endothelium. This may be reduced by oral antioxidant supplementation.
Aim: To assess the effectiveness of antioxidant supplementation for the prevention of acute mountain sickness (AMS).
Design: A parallel-group double blind, randomized placebo-controlled trial.
Methods: The study was conducted in a university clinical research facility and a high altitude research laboratory. Eighty-three healthy lowland volunteers ascended to 5200 m on the Apex 2 high altitude research expedition. The treatment group received a daily dose of 1 g L-ascorbic acid, 400 IU of 
-tocopherol acetate and 600 mg of -lipoic acid (Cultech Ltd., Wales, UK) in four divided doses. Prevalence of AMS was measured using the Lake Louise Consensus score sheet (LLS). Secondary outcomes were AMS severity measured using a novel visual analogue scale, arterial oxygen saturation and pulmonary artery systolic pressure (PASP).
Results: Forty-one subjects were allocated to the antioxidant group, and 42 to the placebo group. There was no difference in AMS incidence or severity between the antioxidant and placebo groups using the LLS at any time at high altitude. At the pre-determined comparison point at Day 2 at 5200 m, 69% of the antioxidant group (25/36) and 66% of the placebo group (23/35) had AMS using the LLS criteria (P = 0.74). No differences were observed between the groups for PASP, oxygen saturation, presence of a pericardial effusion or AMS assessed by VAS.
Conclusion: This trial found no evidence of benefit from antioxidant supplementation at high altitude.
Trial registration number: NCT00664001 [ClinicalTrials.gov]