A higher baseline somatization score at sea level as an independent predictor of acute mountain sickness

OBJECTIVE The current study aimed to identify the predictive values of psychological factors that are evaluated by the Symptoms Checklist-90 (SCL-90) for acute mountain sickness (AMS). METHODS The subjects (n=285, non-acclimatized young Chinese men), who were recruited in July 2013, completed a case report questionnaire. In addition, their vital signs (heart rate [HR], blood pressure and pulse oxygen saturation) were measured, and their psychological factors were examined using the SCL-90 at sea level. AMS was diagnosed using the Lake Louise self-assessment scoring system in the morning of the second day after their arrival at 3450m. RESULTS Of the nine factors of the SCL-90, the AMS patients (AMS score≥3) were characterized by significantly higher scores for baseline somatization [14.0 (5.0) vs. 13.0 (3.0), p<0.001], obsession-compulsion, depression, anxiety and hostility compared with the non-AMS group (all p values<0.05). Spearman's correlation analyses revealed associations between AMS scores and somatization (r=0.316, p<0.001), depression, anxiety, obsession-compulsion, interpersonal sensitivity, hostility, phobic anxiety, paranoid ideation and psychoticism scores (all p values<0.001). Although all nine factors were associated with AMS in a univariate regression (all p<0.05), a further adjusted logistic regression analysis indicated that only baseline somatization score (odds ratio=1.129, p=0.001) was an independent predictor of AMS. Furthermore, some non-AMS often-occurred symptoms (paresthesia, shortness of breath, reduced activity and tinnitus) were also found to be associated with the baseline SCL-90 scores. CONCLUSION AMS is correlated with the baseline somatization score at sea level, which was measured using the SCL-90. A higher baseline somatization score is also an independent predictor of AMS.