RESUMEN
BACKGROUND: Acute mountain sickness (AMS) often occurs in individuals who rapidly travel above 2,500 m. As the convenience of traveling and the development of mountain sports increase, AMS will become an increasingly important public health problem. However, no method to effectively predict AMS before it occurs is currently available. METHODS: This post hoc study investigated whether the 3-Minute Step Test (3MST), which evaluates physical fitness, is predictive of AMS development. The data collected in "Rhodiola crenulata extract for prevention of AMS: a randomized, double-blind, placebo-controlled, crossover trial" was used in the analysis. This study collected 204 observations of 102 participants who made two ascents of Hehuan Mountain (3,100 m) by bus within a 3-month period. Participants completed the 3MST at 250 m (before ascent) and 3,100 m (on Hehuan Mountain). The presence of AMS was accessed using the Lake Louise scoring system. RESULTS: AMS was identified in 124 observations (60.78%). In the univariate analysis, the pre-departure 3MST score (at 250 m) was not significantly associated with AMS (p = 0.498), but the 3MST score measured at 3,100 m, ascent number, pulse rate at 3,100 m, and saturation of peripheral oxygen (SpO2) measured at 3,100 m were significantly correlated with the occurrence of AMS (p = 0.002, 0.039, 0.005, < 0.001, respectively). In a further multivariate analysis, only SpO2 measured at 3,100 m had a significant association with AMS (p = 0.016 and 0.006, respectively). The trend analysis showed that for every 1-point increase in the 3MST score at 3,100 m, the AMS decreased by 4% (adjusted odds ratio [AOR] = 0.96, 95% confidence interval [CI] = 0.92-1.01). CONCLUSION: The 3MST score cannot be a predictor of AMS, but it may have a potential role in predicting ascent safety in high-altitude areas.
RESUMEN
BACKGROUND: Rhodiola crenulata (R. crenulata) is widely used to prevent acute mountain sickness in the Himalayan areas and in Tibet, but no scientific studies have previously examined its effectiveness. We conducted a randomized, double-blind, placebo-controlled crossover study to investigate its efficacy in acute mountain sickness prevention. METHODS: Healthy adult volunteers were randomized to 2 treatment sequences, receiving either 800 mg R. crenulata extract or placebo daily for 7 days before ascent and 2 days during mountaineering, before crossing over to the alternate treatment after a 3-month wash-out period. Participants ascended rapidly from 250 m to 3421 m on two separate occasions: December 2010 and April 2011. The primary outcome measure was the incidence of acute mountain sickness, as defined by a Lake Louise score ≥ 3, with headache and at least one of the symptoms of nausea or vomiting, fatigue, dizziness, or difficulty sleeping. RESULTS: One hundred and two participants completed the trial. There were no demographic differences between individuals taking Rhodiola-placebo and those taking placebo-Rhodiola. No significant differences in the incidence of acute mountain sickness were found between R. crenulata extract and placebo groups (all 60.8%; adjusted odds ratio (AOR) = 1.02, 95% confidence interval (CI) = 0.69-1.52). The incidence of severe acute mountain sickness in Rhodiola extract vs. placebo groups was 35.3% vs. 29.4% (AOR = 1.42, 95% CI = 0.90-2.25). CONCLUSIONS: R. crenulata extract was not effective in reducing the incidence or severity of acute mountain sickness as compared to placebo. TRIAL REGISTRATION: ClinicalTrials.gov NCT01536288.
