Acute mountain sickness (AMS) strikes people who travel too quickly to high altitude, outstripping their ability to acclimatize. AMS is characterized as headache plus loss of appetite, nausea and vomiting, insomnia, or dizziness and fatigue. The incidence of AMS increases with altitude elevation, hypoxia is the primary cause of AMS, inadequately treated AMS may develop into life-threatening cerebral edema, and individual susceptibility remains unpredictable. Understanding the mechanisms underlying AMS is important for clinical prevention and therapy. Here we report that hypobaric hypoxia altered corticotrophin-releasing hormone (CRH) metabolism, triggered cerebral apoptosis, and increased stress hormone levels in plasma in rats. In humans, exercise at low altitude increased CRH and cortisol levels in both plasma and saliva. Lowlanders with high plasma and salivary CRH at low altitude developed AMS after rapid ascent to the Tibetan plateau and high AMS scores were associated with high plasma and salivary CRH levels. Our results suggest that CRH plasma or salivary levels can predict and assess AMS.
This work was supported by the Ministry of Science and Technology of China, National Basic Research Program “973” of China (2012CB518200 and 2006CB504100) and the National Natural Science Foundation of China (31171145 and 30871221) for funding this study.