Relationships between symptoms, moods, performance, and acute mountain sickness at 4,700 meters

Ascents above 4,000 m adversely affect symptoms, moods, and performance and cause acute mountain sickness (AMS). It is assumed that individuals afflicted with AMS will be more susceptible to changes in these other parameters; however, previous studies have suggested that their time courses are different. This investigation analyzed the relationships between symptoms, moods, and performance and a measure of altitude sickness, the AMS-cerebral (AMS-C) factor of the environmental Symptoms Questionnaire (ESQ). We evaluated 20 male soldiers on 11 symptom, 13 mood, and 14 cognitive/motor performance measures after exposure to altitudes of 550 and 4,700 m for 5-7 h and a difference score was calculated for each measure. The difference scores for 70% of the symptom, 46.2% of the mood, and 28.6% of the performance measures were significantly correlated with the AMS-C difference score. The difference scores for each measure were then rank ordered (to standardize for differences across measures) and the sum of the ranks was calculated for each subject's symptoms, moods, and performance. The AMS-C factor score correlated significantly 0.90, 0.77, and 0.59 with these composite measures of symptoms, moods, and performance, respectively. Changes in AMS after 5-7 at 4,700 m were correlated best with changes in symptoms, then moods, and finally performance, suggesting that these parameters may be differentially affected at this point in time.