Table 1.
Subject characteristicsd.
Fig 1.
Overall incidence and daily prevalence of AMS in children trekking on Xue Mountain (3,886 m).
McNemar’s test was used for between-day comparisons. P-values < 0.05 were considered statistically significant. * p < 0.001. AMS, acute mountain sickness.
Table 2.
Overall prevalence (%) of AMS-associated symptoms on different daysc.
Fig 2.
Prevalence of AMS-associated symptoms in males and females.
The prevalence of headache and fatigue was significantly higher among males than females. More than half (67.7%) of the male subjects experienced headache compared to 45.4% of females. The prevalence of fatigue was also higher among males (54%) than females (34.9%). The chi-squared test was used to detect differences in prevalence between male and female subjects. P-values < 0.05 were considered statistically significant. * p < 0.05. AMS, acute mountain sickness; GI symptoms, gastrointestinal symptoms (nausea, vomiting, poor appetite).
Fig 3.
Daily prevalence of AMS-associated symptoms in the AMS and non-AMS groups.
A—Day 1 (Qika Hut, 2,460 m): 26% of the subjects in the AMS group experienced headache and dizziness. Fewer than 7% of the non-AMS group experienced AMS symptoms, and none experienced GI symptoms at this altitude. B—Day 2 (Sanliujiu Hut, 3,100 m): headache was the most prevalent symptom (82.5%) in the AMS group, followed by sleep disturbance. In the non-AMS group, the main symptom was sleep disturbance (46%) followed by dizziness, headache, and fatigue (prevalence < 30% for all). C—Day 3 (Sanliujiu Hut, 3,100 m, after reaching the summit of Xue Mountain, 3,886 m): more than 50% of the AMS group experienced headache, dizziness, fatigue, and sleep disturbances. Sleep disturbance was the most prevalent symptom in both groups. All AMS symptoms were significantly more prevalent in the AMS than the non-AMS group on all 3 days. The sleep disturbance score reflected the sleep quality during the night before evaluation, but the sleep disturbance score on Day 1 was not considered in the analysis because all subjects slept at home (near sea level) on the night before trekking. McNemar’s test was used for within-group comparisons of prevalence, and the chi-squared test was used for between-group comparisons. P-values < 0.05 were considered statistically significant. * p < 0.05. AMS, acute mountain sickness; GI symptoms, gastrointestinal symptoms (nausea, vomiting, poor appetite).
Fig 4.
LLS for each symptom according to group on days 1–3.
A—Day 1 (Qika Hut, 2,460 m): the gastrointestinal (GI) symptom score was lowest in the AMS group. No subject in the non-AMS group experienced GI symptoms at this altitude. B—Day 2 (Sanliujiu Hut, 3,100 m): the sleep disturbance score was the highest LLS in both groups (AMS: 1.29 ± 0.92, non-AMS: 0.68 ± 0.83). In the AMS group, headache and dizziness were the most severe symptoms after sleep disturbance. C—Day 3 (Sanliujiu Hut, 3,100m, after reaching the Xue Mountain summit, 3,886 m): similar to previous days, the sleep disturbance symptoms were the most severe, and GI symptoms the least severe, in both groups. On all 3 days, all of the LLS were significantly higher for the AMS group than for the non-AMS group. The sleep disturbance score reflected the sleep quality during the night before evaluation, but the sleep disturbance score of Day 1 was not considered in the analysis because all subjects slept at home (near sea level) on the night before trekking. The Wilcoxon signed rank test was used to detect within-group differences in the LLS for each symptom, and the Mann-Whitney rank sum test was used to compare LLS for each symptom between groups. P-values < 0.05 were considered statistically significant. * p < 0.05. LLS, Lake Louise Score; AMS, acute mountain sickness; GI symptoms, gastrointestinal symptoms (nausea, vomiting, poor appetite).