Physiological Variables Associated with the Development of Acute Mountain Sickness

Objective To identify the physiological variables associated with the development of acute mountain sickness (AMS). Methods Eighty four young Chinese men residing at low altitude were taken to an altitude of 4000 m within 40 hours. At sea level and at high altitude, we measured the heart rate, blood pressure, and peripheral oxygen saturation (SpO 2 ) respectively. We also collect blood samples from each participants before and after the altitude elevation. The blood routine and biochemical examinations were performed for all blood samples. The revised Lake Louise Criteria was adopted to diagnose AMS after the subjects arrived at the target high altitude. The association between the presence of AMS and subjects' physiological variables were analysed statistically. Results Of 84 participants, 34 (40.5%) developed AMS. Compared with non AMS group, in the AMS group, the percentage of neutrophils was significantly higher (64.5%±11.2% vs. 58.1%±8.8%, P =0.014), while the level of SpO 2 was significantly lower (79.4%±5.4% vs. 82.7%±5.6, P=0.008). Binary logistic regression analyses emphasized the association of neutrophils (OR: 1.06, 95% CI: 1.01-1.12, P=0.034) and SpO 2 level (OR: 0.87, 95% CI : 0.79-0.95, P=0.004) with the development of AMS. Conclusion The ability to sustain SpO 2 after altitude elevation and the increase of neutrophils were associated with the development of AMS in young males.