AUTHOR=Gao Chun , Qi Guo-Dong , Wang Dan , Zhang Zhao-Hui , Liu Zhong-Xing , Ge Rui-Dong , Yong Zong , Yan Li-E 

TITLE=Incidence and risk factors of severe acute high-altitude illness in healthy adults first entering the northern Tibetan Plateau of over 5,000 m

JOURNAL=Frontiers in Public Health

VOLUME=Volume 12 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1400236

DOI=10.3389/fpubh.2024.1400236

ISSN=2296-2565

ABSTRACT=Background: Our study was designed to determine the incidence and risk factors of severe acute high-altitude illness (AHAI) in healthy adults first entering the northern Tibetan Plateau of over 5000 m. Methods: In our prospective observational study, 500 people were enrolled and they were scheduled for assignment fast ascending to the Plateau. Primary outcome variable is adopted, and severe AHAI is defined as that people have serious symptoms which cannot be ameliorated by general treatment and they must be evacuated to lower altitudes. According to the inclusion and exclusion criteria, a cohort of 383 healthy people entered the statistical analysis. The incidence of severe AHAI was calculated, the risk factors were determined, and the differences of most severe symptoms were compared. Results: Sixty-eight people were diagnosed with severe AHAI and the incidence was 17.8%. Compared with the people without severe AHAI, the people with severe AHAI had higher percentages of age over 40, the Chinese Han nationality and living at the altitude of < 1500 m, a lower percentage of the Yi nationality, a lower altitude of permanent residence, and decreased levels of lymphocyte count and hemoglobin concentration. Multivariable logistic regression showed that the mean altitude of permanent residence (per kilometer, AOR=0.464; 95% CI, 0.304-0.708; P<0.001) and lymphocyte count (AOR=0.606; 95% CI, 0.378-0.970; P=0.037) were the independent risk factors. Headache and dyspnea ranked in the top two of the most severe symptoms for people with severe AHAI. Conclusion:Living at lower altitudes and having a decreased lymphocyte level were the risk factors of severe AHAI in healthy adults first entering the Plateau of over 5000 m.