Traditional Chinese Medicine Constitution Characteristics and Influencing Factors for Acute Mountain Sickness Susceptibility in Rapidly Ascending High-Altitude Populations: A Cross-Sectional Survey

Background: Acute Mountain Sickness(AMS) is a significant health concern for individuals rapidly ascending to high altitudes. In severe cases, the condition can develop into high-altitude pulmonary edema and high-altitude cerebral edema, which can have a significant impact on the quality of life of individuals entering Tibet and even pose a threat to their lives. The occurrence of AMS is closely related to factors such as altitude, the time of year of entry into Tibet, and individual activities. However, individual differences in the manifestation of AMS and the subsequent physiological responses are evident, with these responses varying among individuals of differing body types within the same environmental context. The Traditional Chinese Medical Constitution (TCMC) is a significant indicator of health status and may be associated with an increased propensity for plateau reactions. However, owing to a combination of environmental influences, subject demographics, and other factors, the current body of research related to AMS and TCMC is relativelylimited. Objective: To investigate AMS-susceptible TCMC types and key influencing factors in populations rapidly ascending to Tibet, providing evidence for TCM-based prevention and individualized AMS management. Methods: Thiscross-sectional study enrolled 1,482 eligible participants (healthy males aged 18--40 years who werenewly ascended to high altitude). Data collection included the following: 1) questionnaires(demographics, lifestyle, anxiety, insomnia); 2) physicalexaminations (vital signs: respiration, heart rate, SpO₂, blood pressure) and body mass index (BMI); 3) TCMC assessment viathe Classification and Determination of TCMC standard; and 4) AMS diagnosis and severity grading via the Lake Louise Score (LLS). Spearman correlation was used to analyze therelationships between variables. Multivariate logistic regression (backward stepwise, entry P<0.25) identified independent AMS risk factors. Results: The overall incidence of AMS was 32.9% (488 out of 1482 cases). The prevalence of unbalanced constitutions was markedly greaterin the AMS group than in the non-AMS group (32.6% vs. 7.6%; χ² =161.8, P<0.001). Amongpatients with AMS and an unbalanced constitutions, Qi-deficiency was the most prevalent, accounting for 78.0% of the cases. The incidence of AMS was observed to vary significantly according to different constitutions, with rates of 72.9% for Qi-deficiency and26.3%for a Balanced constitution. Univariate analysis revealed significant correlations (all P<0.001): SpO₂ was negatively correlated with AMS (r=-0.231); Insomnia (r=0.272), Anxiety (r=0.297), Unbalanced constitution tendency (r = 0.333), Season (winter=1; r = 0.122), Altitude (r=0.157), and BMI (r=0.127) were positively correlated. Multivariate analysis revealed the following independent risk factors: Anxiety (aOR=1.16, 95% CI: 1.08–1.25, P<0.001), Insomnia(aOR=1.09, 95% CI: 1.03–1.16, P=0.003), Unbalancedconstitution tendency (aOR=1.06, 95% CI: 1.02–1.10, P=0.002), and SpO₂ (aOR=0.91, 95% CI: 0.87–0.95, P<0.001). BMI showed a weak positive association (aOR=1.02, 95% CI: 1.00–1.04;P=0.041). Season, altitude, and blood pressure lost significance after adjustment (P>0.05). Conclusion: Qi-deficiency is the most common AMS-susceptible TCMC. Key modifiable risk factors include insomnia, anxiety, and low SpO₂. The influencesof season and altitude are mediated through physiological, psychological, and constitutional factors. These findings advocate for TCMC-differentiated prevention strategies for AMS. These strategies encompass preemptive qi-tonifying interventions for susceptible individuals, psychological support, and sleep optimization.