Assessment of Acute Mountain Sickness Using 1993 and 2018 Versions of the Lake Louise Score in a Large Chinese Cohort

Chen, Renzheng, Yong Wang, Chen Zhang, Xiaolin Luo, Jie Yang, Chuan Liu, and Lan Huang. Assessment of acute mountain sickness using 1993 and 2018 versions of the Lake Louise Score in a large Chinese cohort. High Alt Med Biol. 22:362-368, 2021. Background: This study uses Lake Louise Score (LLS) in its original (LLS1993) and new (LLS2018) versions to assess acute mountain sickness (AMS) and aims to provide more clinical information about the AMS scoring system. Methods: We enrolled 1,026 male Chinese soldiers who traveled from an altitude of 500 to 3,700 m by airplane in 2.5 hours. We observed each subject's symptoms after arrival at 3,700 m in 24 and 48 hours. Each item was dropped from LLS1993 to evaluate its sensitivity and effect on AMS diagnosis. The relationship between each symptom and AMS was assessed by correlation analysis. Exploratory and confirmatory factor analyses evaluated the factor structure of LLS, while the ordinal alpha coefficient was calculated to determine its internal consistency. Results: Four hundred fifty-nine subjects were not followed up on day 2. We defined two observed cohorts (cohort 1, n = 1,026 and cohort 2, n = 567). Headache was the most common symptom in 24 hours, while sleep disturbance was the fourth-most common symptom at 24 hours and the most common symptom at 48 hours. When we dropped gastrointestinal symptoms, the drop rate was lowest in each situation (1.0% in cohort 1, 1.3% in cohort 2 at 24 hours, and 5.7% in cohort 2 at 48 hours, respectively). The incidence of AMS decreased from 18.4% at 24 hours to 36.4% at 48 hours when lost sleep disturbance in cohort 2. Moreover, the statistical method of Mantel/Haenszel square test was used for correlation analysis and the results showed a correlation between sleep disturbance and AMS. Besides, both LLS1993 and LLS2018 had acceptable internal consistencies, and all items had good loading coefficients in LLS1993. Conclusions: We have demonstrated that there could be an association between sleep disturbance and AMS diagnosis. Both LLS1993 and LLS2018 applied to young Chinese men.