Epidemiology of Acute Mountain Sickness on Jade Mountain, Taiwan: An Annual Prospective Observational Study

Abstract

Acute mountain sickness (AMS) is a pathophysiological symptom complex that occurs in high altitude areas. The AMS prevalence is reportedly 28% on Jade Mountain, the highest mountain (3952 m) in Taiwan. We conducted this study owing to the lack of annual epidemiological data on AMS in Taiwan. Between April 2007 and March 2008, 1066 questionnaires were completed by trekkers visiting Paiyun Lodge on Jade Mountain. Information in the questionnaire included demographic data, mountaineering experience, AMS history, and trekking schedule. Weather data were obtained from the Central Weather Bureau of Taiwan. The Lake Louise AMS score was used to record symptoms and diagnose AMS. The chi-square test or the Student t test was used to evaluate associations between variables and AMS. In our study, the AMS prevalence was 36%. It increased significantly at different rates at different locations on the Jade Mountain trail and varied significantly in different months. Rainy weather tended to slightly increase the incidence of AMS. A lower incidence of AMS was correlated with hig-altitude trekking experience or preexposure (p < 0.05), whereas a higher incidence of AMS was correlated with a prior history of AMS (p < 0.05). The trekkers with AMS were significantly younger, ascended faster from their residence to the entrance or to Paiyun Lodge, and ascended slower from the entrance to the Paiyun Lodge (p < 0.05), but the differences lacked clinical significance. No differences in the incidence of AMS based on blood type, gender, or obesity were observed. The most common symptom among all trekkers was headache, followed by difficulty sleeping, fatigue or weakness, gastrointestinal (GI) symptoms, and dizziness or lightheadedness. In conclusion, the AMS prevalence on Jade Mountain was 36%, varied by month, and correlated with trekking experience, preexposure, and a prior history of AMS. The overall presentation of AMS was similar to that on other major world mountains.

Impact of Sleeping Altitude on Symptoms of Acute Mountain Sickness on Mt. Fuji

“…Numerous previous studies showed reduced effects of sex (Hackett et al, 1976;Maggiorini et al, 1990;Schneider et al, 2002;Vardy et al, 2006;Wang et al, 2010) and age (Schneider et al, 2002;Vardy et al, 2005;Wang et al, 2010) on AMS, but some studies found a higher risk of AMS in women (Honigman et al, 1993) or men ( Johnson and Rock, 1988), and in younger adults (Hackett et al, 1976;Honigman et al, 1993) or the elderly (Maggiorini et al, 1990). Our results suggest that sex and age differences are of little importance in terms of the prevalence and severity of AMS among climbers of Mt.…”

“…Although future studies may be necessary, we could not completely rule out any statistical errors, such as type I errors. Moreover, as most of these studies were conducted for different ethnic groups, further explanation is difficult; however, a previous study demonstrated that sex and age differences did not affect the prevalence of AMS among Taiwanese (Asian ethnicity) climbers of Jude Mountain (Wang et al, 2010). Therefore, although future studies are required, sex and age differences Total staying time means the total time from the start of ascending at the fifth station to the start of descending from the summit.…”

Incidence of acute mountain sickness in young adults at 3200 meters: comparison of the Lake Louise Scoring and Chinese Scoring Systems

“…Vardy et al (2006) found that the incidence of AMS was 0 at 2500-3000 m and was 10% at 3000-4000 m. Karinen et al (2010) reported an incidence of 10% at 3500 m and 21% at 4300 m, whereas Newcomb et al (2011) found that 21% of Caucasian hikers suffered from AMS at 4470 m. Using subjects with the same ethnic background as those of our study, researchers from Taiwan found that the incidence of AMS at Jade mountain (3950 m) was approximately 36% (Wang et al, 2010), a value significantly higher than that observed in the present study (17.11% at 3200 m). There are several possible explanations for the discrepancy between our data and those of Wang et al First, the altitude in the latter study was higher than that in ours (3950 vs 3200 m).…”

Association of Arterial Oxygen Saturation and Acute Mountain Sickness Susceptibility: A Meta-analysis

“…Previous studies have shown that body mass index (BMI) is inversely related to AMS susceptibility [15,16]. Other predictors for AMS that have been reported include the velocity of ascent and experience of climbing at high altitude [17]. S O 2 [Please use ''SO2'' or ''SaO2'' consistently throughout the manuscript.]…”