Oral antioxidant supplementation does not prevent acute mountain sickness: double blind, randomized placebo-controlled trial.
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.


OBJECTIVE
To assess the effectiveness of antioxidant supplementation for the prevention of acute mountain sickness (AMS).


METHODS
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 alpha-tocopherol acetate and 600 mg of alpha-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.


CONCLUSIONS
This trial found no evidence of benefit from antioxidant supplementation at high altitude.


BACKGROUND
NCT00664001.
Baillie
J K
JK
Department of Anaesthesia, Critical Care and Pain Medicine, University of Edinburgh, Royal Infirmary of Edinburgh, Edinburgh, UK. j.k.baillie@altitude.org
Thompson
A A R
AA
Irving
J B
JB
Bates
M G D
MG
Sutherland
A I
AI
Macnee
W
W
Maxwell
S R J
SR
Webb
D J
DJ
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000532:Altitude Sickness / Q000517:prevention & control*; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D009051:Mountaineering; D013223:Statistics as Topic; D008063:Thioctic Acid / Q000008:administration & dosage*; D055815:Young Adult; D024502:alpha-Tocopherol / Q000008:administration & dosage*
D000975:Antioxidants; D008063:Thioctic Acid; D024502:alpha-Tocopherol; D001205:Ascorbic Acid