The relationship between baseline exhaled nitric oxide levels and acute mountain sickness

Acute mountain sickness (AMS) is a common disabling condition observed in people ascending to high altitudes. However, a simple predictive test for AMS is not known. The aim of this study was to assess the relationship between baseline exhaled nitric oxide (FENO) and AMS occurrence.

Eighty healthy lowland Chinese adults were recruited for this study. FENO was measured at baseline, as well as 6 and 24 hours after arrival in Tibet. The standard Lake Louise Score (LLS) consensus symptoms questionnaire was used to assess the incidence and severity of AMS.

Individuals with a high LLS (> 3) had higher FENO levels at baseline and after arrival in Tibet than people with a low LLS (≤ 3) (baseline: 22.9 ± 11.9 versus 16.7 ± 6.4; 6 hours: 26.2 ± 16.7 versus 17.9 ± 5.7; 24 hours: 24.9 ± 13.1 versus 16.3 ± 1.7; all P < 0.01). Evaluation of risk factors revealed that female gender, diabetes and not smoking were associated with a high AMS score (all P < 0.05), but that hypertension showed no association (P > 0.05).

This prospective observational study suggests that baseline FENO levels may be positively correlated with AMS in healthy Chinese lowlanders.