Is acute mountain sickness related to trait anxiety? A normobaric chamber study.

Introduction: Some mountaineers are more prone to the occurrence of acute mountain sickness (AMS) than others. State anxiety during altitude exposure might be associated with AMS development. We hypothesized that trait anxiety might be higher in AMS cases compared to non-AMS cases. The aim of the present study was to study the relationship between AMS development and trait anxiety.

Methods: In an observational study design, AMS incidence during a 12-hour exposure to normobaric hypoxia (FO=12.6%, equivalent to 4500m) was determined by the Lake Louise Scoring System. Trait anxiety (State Trait Anxiety Inventory) and confounding variables were assessed in a follow-up questionnaire (37months after hypoxic exposure).

Results: Twenty nine participants returned the follow-up questionnaire. AMS incidence was 38%. Both unadjusted and adjusted logistic regression analyses did not reveal trait anxiety as a significant variable in relation to AMS.

Discussion: Based on the findings of this preliminary study, there is no evidence that AMS development under normobaric conditions is related to trait anxiety. Differences to previous studies might be explained by the type of hypoxia, by different sample characteristics and by considering sleep disturbances in the calculation of the AMS score. However, future studies with larger sample sizes may help to clear the relationship between AMS development and the personality factor anxiety.