57 Rhodiola Crenulata Extract Prophylaxis for Acute Mountain Sickness: A Randomized, Double Blind, Placebo Controlled, Crossover Trial

Abstract

Study Objectives: Acute mountain sickness occurs in unacclimatized individuals rapidly ascending to high altitude. Rhodiola crenulata is widely used to prevent cerebrospinal fluid in Himalayan areas and in Lhasa in Tibet, but no studies have examined its effectiveness in humans. We conducted a randomized, double blind, placebo controlled, and crossover study to investigate the efficacy of Rhodiola crenulata in cerebrospinal fluid prevention.Methods: We randomized unacclimatized adults to receive Rhodiola crenulata extract or placebo, initially taking 800 mg daily for 7 days before ascent and 2 days during mountaineering, separated by a 3-month washout period. Participants had rapid ascent from 250 m above the sea to a training camp (3100 m) and the East Peak (3421 m) of Hehuan Mountain in Taiwan, on 2 separate occasions: once in December 2010 and once in April 2011. The primary outcome measure was incidence of acute mountain sickness defined by Lake Louise acute mountain sickness score ≥ 3 with headache and one other symptom. Secondary outcome measures included blood oxygen content, severity of the syndrome (Lake Louise score ≥ 5), incidence of headache, and severity of headache.Results: One hundred and twenty-five subjects (102 completed the trial) were assigned to 2 sequences separately. Rhodiola crenulata extract was not significantly different from placebo for any outcome. The incidence of acute mountain sickness was the same among participants who received either Rhodiola extract or placebo (all 60.8%). After adjusting for period effects, the risk of cerebrospinal fluid in participants taking Rhodiola was 1.02 times that of participants taking placebo (P=0.90). Severe acute mountain sickness occurred in 35.3% of participants taking Rhodiola crenulata and 29.4% taking placebo (P=0.13). The SpO2 was similar in those taking Rhodiola and in those taking placebo (88.6±3.9% versus 88.6±4.3%; P=0.74).Conclusion: Rhodiola crenulata extract is not effective in reducing the incidence or severity of acute mountain sickness when compared with placebo, and has no protective benefit for any outcome measure. Study Objectives: Acute mountain sickness occurs in unacclimatized individuals rapidly ascending to high altitude. Rhodiola crenulata is widely used to prevent cerebrospinal fluid in Himalayan areas and in Lhasa in Tibet, but no studies have examined its effectiveness in humans. We conducted a randomized, double blind, placebo controlled, and crossover study to investigate the efficacy of Rhodiola crenulata in cerebrospinal fluid prevention. Methods: We randomized unacclimatized adults to receive Rhodiola crenulata extract or placebo, initially taking 800 mg daily for 7 days before ascent and 2 days during mountaineering, separated by a 3-month washout period. Participants had rapid ascent from 250 m above the sea to a training camp (3100 m) and the East Peak (3421 m) of Hehuan Mountain in Taiwan, on 2 separate occasions: once in December 2010 and once in April 2011. The primary outcome measure was incidence of acute mountain sickness defined by Lake Louise acute mountain sickness score ≥ 3 with headache and one other symptom. Secondary outcome measures included blood oxygen content, severity of the syndrome (Lake Louise score ≥ 5), incidence of headache, and severity of headache. Results: One hundred and twenty-five subjects (102 completed the trial) were assigned to 2 sequences separately. Rhodiola crenulata extract was not significantly different from placebo for any outcome. The incidence of acute mountain sickness was the same among participants who received either Rhodiola extract or placebo (all 60.8%). After adjusting for period effects, the risk of cerebrospinal fluid in participants taking Rhodiola was 1.02 times that of participants taking placebo (P=0.90). Severe acute mountain sickness occurred in 35.3% of participants taking Rhodiola crenulata and 29.4% taking placebo (P=0.13). The SpO2 was similar in those taking Rhodiola and in those taking placebo (88.6±3.9% versus 88.6±4.3%; P=0.74). Conclusion: Rhodiola crenulata extract is not effective in reducing the incidence or severity of acute mountain sickness when compared with placebo, and has no protective benefit for any outcome measure.