Acute Mountain Sickness Is Associated With a High Ratio of Endogenous Testosterone to Estradiol After High-Altitude Exposure at 3,700 m in Young Chinese Men

Abstract

Background: A large proportion of populations suffer from acute mountain sickness (AMS) after exposure at high altitude. AMS is closely related with age and gender implying that the sex hormones may play critical roles in AMS. Our observational study aimed to identify the association between the endogenous testosterone (T), estradiol (E2) and AMS.Methods: A total of 113 subjects were recruited in 2012. The participants were evaluated at 500 m and after acute (1 day) and short-term (7 days) high-altitude exposure at 3,700 m. The subjects also completed a case report form questionnaire and underwent blood pressure measurements and an echocardiography examination. The red blood cell (RBC) count, Hb concentration ([Hb]), hematocrit (HCT), E2, T, and erythropoietin (EPO) were measured.Results: Upon acute high-altitude exposure, E2 and EPO were significantly lower in AMS+ group, and T/E2 and stroke volume were higher. On the 1st day, AMS score correlated positively with the T/E2 ratio while it negatively correlated with E2. After 7 days at 3,700 m, the AMS+ subjects had higher erythropoietic parameters: EPO, T, and T/E2 were significantly higher in the AMS+ group. [Hb], RBC count, HCT, EPO, T and T/E2 were also correlated with AMS score. EPO, HCT, and the RBC count were also correlated with T/E2. Regression analyses indicated that T/E2 significantly correlated to AMS score and T/E2 on the 1st day was an independent predictor for AMS on the 7th day.Conclusion: AMS was correlated with T/E2 ratio and EPO. After short-term exposure, higher T/E2 may contribute to AMS together with EPO via erythropoiesis. Furthermore, T/E2 level at high altitude in the early stage was an independent predictor for AMS in the latter stage.

Association between physiological responses after exercise at low altitude and acute mountain sickness upon ascent is sex-dependent

“…Higher incidence of AMS in women may be explained by the effects of hormones. First, testosterone possess potent erythropoiesis action [29]. High serum testosterone and hemoglobin levels are conducive to improvements in oxygen transport, normal cellular function and thus lower susceptibility to AMS.…”

Sex-based differences in the prevalence of acute mountain sickness: a meta-analysis

“…The perspective in the existing literature is that the differences between men and women are mainly determined by the physical differences and the different hormone levels [13, 14]. Some investigators believe that the differences in the prevalence of AMS between men and women is also affected by hormones or other factors associated with hormones [15]. However, that is only hypothesis, and the pathophysiological mechanism of AMS is still not entirely clear.…”

Intermittent Hypoxia Exposure Helps to Restore the Reduced Hemoglobin Concentration During Intense Exercise Training in Trained Swimmers

“…For instance, the levels of serum T of 52 male soldiers decreased significantly after a 5,380 m altitude exposure for half a year, while increased significantly after another half a year ( He et al, 2015 ). However, Ding et al, found that although 113 male subjects showed a significant increase in the serum T level one day after a 3,700 altitude exposure, their serum T levels fell below their baselines seven days later ( Ding et al, 2018 ). These divergent results may be attributed to divergent physical characteristics of subjects and different duration of hypoxia exposure.…”