# Qi deficiency constitution increases risk of acute mountain sickness via reduced aerobic fitness

## TL;DR

People with Qi deficiency in Traditional Chinese Medicine are more likely to get acute mountain sickness due to lower aerobic fitness.

## Contribution

This study identifies Qi deficiency constitution as an independent risk factor for AMS, mediated through reduced aerobic fitness.

## Key findings

- Qi deficiency constitution was independently associated with increased AMS risk (adjusted OR = 1.09).
- Aerobic fitness, measured by 3,000-meter run time, mediated the relationship between Qi deficiency and AMS.
- Assessing TCM constitution could help identify individuals at higher risk for AMS before high-altitude exposure.

## Abstract

Acute mountain sickness (AMS) is a common disorder affecting individuals who are exposed to high-altitude environments, generally defined as an elevation of above 2,500 meters. Identifying risk factors for AMS susceptibility before exposure is essential for prevention. According to current research, different constitution types exhibit varying tolerance to acute hypoxia. Exploring the relationship between Traditional Chinese Medicine (TCM) constitution and AMS may therefore provide novel perspectives for prevention and treatment from a TCM standpoint.

A total of 183 healthy young male participants were enrolled and assessed for TCM constitution, demographic characteristics, clinical indices, and 3,000-meter run performance at low altitude (200 m). After rapid ascent from low altitude to 3,600 m by airplane within 3 h, participants were evaluated for AMS using the Lake Louise Score (LLS). Logistic regression was applied to assess the association between TCM constitution types and AMS, and then linear regression was applied to explore factors associated with Qi deficiency constitution. Structural equation modeling (SEM) was employed to investigate whether aerobic fitness, as reflected by 3,000-meter run performance, mediated the relationship between Qi deficiency constitution and AMS.

The incidence of AMS was 40.4%. Among the nine TCM constitution types, only Qi deficiency was independently associated with an increased risk of AMS (adjusted OR = 1.09, 95% CI: 1.01–1.19, p = 0.03). Qi deficiency was significantly associated with 3,000-meter run time, red blood cell count, hemoglobin level, and alcohol intake status. SEM revealed that 3,000-meter run time significantly mediated the association between Qi deficiency and AMS (indirect effect = 0.071, 95% CI: −0.003 to 0.090, p = 0.004), while the direct effect was not statistically significant.

Qi deficiency constitution is an independent risk factor for AMS, and this association is mediated through reduced aerobic fitness, reflected by 3,000-meter run performance. Assessing TCM constitution could be a new way to identify individuals at higher risk for AMS before high-altitude exposure. Pre-acclimatization strategies aimed at improving Qi deficiency or enhancing aerobic capacity could help prevent AMS in susceptible populations.