ANTIOXIDANT SUPPLEMENTATION DOES NOT REDUCE INCIDENCE OR SEVERITY OF ACUTE MOUNTAIN SICKNESS AT 4300 M

Abstract

The pathophysiology of acute mountain sickness (AMS) may be related to oxidative stress raising the possibility that antioxidants represent an alternate therapy for AMS. PURPOSE To test the hypothesis that antioxidant supplementation would decrease the incidence and severity of AMS during two weeks of elevated energy expenditure and caloric deficit at 4300 m. METHODS Eighteen trained males (25 ± 1 yr, mean ± SE) completed the Environmental Symptoms Questionnaire III (ESQ) and Lake Louise Questionnaire (LLQ) at sea level (SL) and daily during two weeks at high altitude (HA) (4300 m). During both SL and HA testing subjects were provided with a low antioxidant diet that maintained caloric balance at SL. However, while at HA energy expenditure was increased to achieve a caloric deficit of ∼1500 kcal·d−1. Following SL testing subjects were divided into two groups matched for ventilatory chemosensitivity, VO2peak, body mass, body composition, and age. In double blind fashion the two groups were assigned to either the placebo (PL) or antioxidant (AO) group and began supplementation three weeks prior to going to HA. RESULTS There were no significant differences in AMS incidence or severity between PL and AO on any day. The incidence of AMS as measured by the ESQ AMS- Cerebral factor score (AMS-C) peaked on day 1 of HA with 13 of 18 subjects reaching the criterion score. The AMS-C score was significantly elevated above SL on days 1–4 of HA (SL 0.156 ± 0.051 vs. HA1–4 0.964 ± 0.321, P < 0.05). These results were confirmed with the analysis of the ESQ AMS-Respiratory factor score and LLQ data. CONCLUSIONS Antioxidant supplementation does not reduce the incidence or severity of AMS during two weeks of elevated energy expenditure and caloric deficit at 4300 m. Supported by the Departments of Veterans Affairs and Defense