A Prospective Epidemiological Study of Acute Mountain Sickness in Nepalese Pilgrims Ascending to High Altitude (4380 m)

<div><p>Background</p><p>Each year, thousands of pilgrims travel to the Janai Purnima festival in Gosainkunda, Nepal (4380 m), ascending rapidly and often without the aid of pharmaceutical prophylaxis.</p><p>Methods</p><p>During the 2012 Janai Purnima festival, 538 subjects were recruited in Dhunche (1950 m) before ascending to Gosainkunda. Through interviews, subjects provided demographic information, ratings of AMS symptoms (Lake Louise Scores; LLS), ascent profiles, and strategies for prophylaxis.</p><p>Results</p><p>In the 491 subjects (91% follow-up rate) who were assessed upon arrival at Gosainkunda, the incidence of AMS was 34.0%. AMS was more common in females than in males (RR = 1.57; 95% CI = 1.23, 2.00), and the AMS incidence was greater in subjects >35 years compared to subjects ≤35 years (RR = 1.63; 95% CI = 1.36, 1.95). There was a greater incidence of AMS in subjects who chose to use garlic as a prophylactic compared to those who did not (RR = 1.69; 95% CI = 1.26, 2.28). Although the LLS of brothers had a moderate correlation (intraclass correlation = 0.40, p = 0.023), sibling AMS status was a weak predictor of AMS.</p><p>Conclusions</p><p>The incidence of AMS upon reaching 4380 m was 34% in a large population of Nepalese pilgrims. Sex, age, and ascent rate were significant factors in the development of AMS, and traditional Nepalese remedies were ineffective in the prevention of AMS.</p></div

The results of multiple binary logistic regression for the individual predictors of AMS in Nepalese pilgrims upon arrival to Gosainkunda (4380 m).

†<p>Males, subjects ≤35 years, and the 2-day ascent group were used as the reference categories for the calculation of odds ratios.</p>*<p>This result is significant (<i>i.e.</i>, p<0.05).</p

Characteristics of Nepalese pilgrims assessed upon arrival to Gosainkunda (4380 m).

<p>Data are presented as mean (standard deviation) or as a percent.</p

Statistical relationships between dichotomous variables and the incidence of acute mountain sickness (AMS) in Nepalese pilgrims upon arrival to Gosainkunda (4380 m).

†<p>The age indicator was missing 3 values due to incomplete data forms.</p>‡<p>The 3-day ascent group was removed from the analysis of ascent rate data (see text).</p>*<p>This result is statistically significant (<i>i.e.</i>, p<0.05).</p

The frequency of Lake Louise Scores in Nepalese pilgrims (n = 491) upon arrival to Gosainkunda (4380 m).

<p>The frequency of Lake Louise Scores in Nepalese pilgrims (n = 491) upon arrival to Gosainkunda (4380 m).</p

The ascent profile from Dhunche (1950 m) to Gosainkunda (4380 m).

<p>All subjects ascended to Gosainkunda via this route in 1, 2, or 3 days. The average grade of the ascent was approximately 12%.</p

Statistical relationships between the use of pharmaceutical and dietary prophylaxis and the incidence of acute mountain sickness (AMS) in Nepalese pilgrims upon arrival to Gosainkunda (4380 m).

*<p>This result is statistically significant (<i>i.e.</i>, p<0.05).</p