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

Background: Acute mountain sickness (AMS) is the mildest form of acute altitude illnesses, and consists of non-specific symptoms when unacclimatized persons ascend to elevation of ≥2500 m. Risk factors of AMS include: the altitude, individual susceptibility, ascending rate and degree of pre-acclimatization. In the current study, we examined whether physiological response at low altitude could predict the development of AMS.

EPAS1 and VEGFA gene variants are related to the symptoms of acute mountain sickness in Chinese Han population: a cross-sectional study.

Background: More people ascend to high altitude (HA) for various activities, and some individuals are susceptible to HA illness after rapidly ascending from plains. Acute mountain sickness (AMS) is a general complaint that affects activities of daily living at HA. Although genomic association analyses suggest that single nucleotide polymorphisms (SNPs) are involved in the genesis of AMS, no major gene variants associated with AMS-related symptoms have been identified.

EDN1 gene potentially involved in the development of acute mountain sickness.

Previous investigations have indicated that environmental and genetic factors collectively contribute to the development of acute mountain sickness (AMS), but whether the EDN1 gene is involved in AMS remains to be elucidated. A total of 356 healthy male soldiers who had not traveled to high altitudes in the previous 12 months were enrolled in our study. All participants were taken by plane from 500 m (Chengdu in Sichuan Province) to a 3700 m highland (Lhasa) within 2 hours.

The onset of sleep disturbances and their associations with anxiety after acute high-altitude exposure at 3700 m.

Sleep disturbances and psychiatric repercussions pose great challenges at high altitude; however, few studies have investigated sleep disturbance and anxiety profiles and their associations after acute exposure in consecutive patients. Thus, we aimed to study the profiles of sleep disturbances in consecutive patients after high-altitude exposure and the association of such disturbances with anxiety. A total of 668 participants were recruited at sea level and 3700 m.

Budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme upon high-altitude exposure.

Introduction: Inhaled budesonide is a novel approach to prevent acute mountain sickness (AMS). However, its mechanism is not completely understood. We aimed to investigate the effects of budesonide and dexamethasone on renin-angiotensin-aldosterone system in AMS prevention.

Inhibition of Store-Operated Calcium Entry Protects Endothelial Progenitor Cells from H2O2-Induced Apoptosis.

Store-operated calcium entry (SOCE), a major mode of extracellular calcium entry, plays roles in a variety of cell activities. Accumulating evidence indicates that the intracellular calcium ion concentration and calcium signaling are critical for the responses induced by oxidative stress. The present study was designed to investigate the potential effect of SOCE inhibition on H2O2-induced apoptosis in endothelial progenitor cells (EPCs), which are the predominant cells involved in endothelial repair.

Physiological and psychological factors associated with onset of high-altitude headache in Chinese men upon acute high-altitude exposure at 3700 m.

Aim We aimed to identify clinical characteristics and risk factors associated with onset of high-altitude headache (HAH) after acute exposure at 3700 m. Method In two hours, 163 individuals ascended by plane to 3700 m. Demographic information, physiological and psychological measurements, cognitive function, physical work capacity tests and profile of mood states within one week prior to the departure and within 24 hours after arrival were examined.

Principal Component Analysis and Risk Factors for Acute Mountain Sickness upon Acute Exposure at 3700 m.

Objective: We aimed to describe the heterogeneity in the clinical presentation of acute mountain sickness (AMS) and to identify its primary risk factors.

Methods: The participants (n = 163) received case report form questionnaires, and their heart rate (HR), oxygen saturation (SpO2), echocardiographic and transcranial Doppler variables, ability to perform mental and physical work, mood and psychological factors were assessed within 18 to 22 hours after arriving at 3700 m from sea level (500 m) by plane. First, we examined the differences in all variables between the AMS-positive and the AMS-negative groups.

A specific objective supplemental factor in evaluating acute mountain sickness: ΔHR in combination with SaO2.

Background: So far, there have been no measurements confirmed useful in diagnosing acute mountain sickness (AMS). The aim of this study was to determine the role of heart rate (HR) difference (ΔHR) and oxygen saturation ( SaO2) as objective risk factors in aiding the diagnosis of AMS.

Methods: A total of 1,019 participants were assigned to either the acute exposure group (AEG): from 500 m to 3,700 m by flight within 2.

Reduction of Store-Operated Ca(2+) Entry Correlates with Endothelial Progenitor Cell Dysfunction in Atherosclerotic Mice.

The dysfunction of endothelial progenitor cells (EPCs) has been shown to prevent endothelial repair during the development of atherosclerosis (AS). Previous studies have revealed that store-operated calcium entry (SOCE) is an important factor in regulating EPC functions. However, whether this is also the mechanism in AS has not been elucidated.

Correlation between blood pressure changes and AMS, sleeping quality and exercise upon high-altitude exposure in young Chinese men.

Background: Excessive elevation of arterial blood pressure (BP) at high altitude can be detrimental to our health due to acute mountain sickness (AMS) or some AMS symptoms. This prospective and observational study aimed to elucidate blood pressure changes induced by exposure to high-altitude hypoxia and the relationships of these changes with AMS prevalence, AMS severity, sleep quality and exercise condition in healthy young men.

Methods: A prospective observational study was performed in 931 male young adults exposed to high altitude at 3,700 m (Lhasa) from low altitude (LA, 500 m).

Relationship between excessive erythrocytosis and acute mountain sickness: a field study.

Background: Alterations in hematology, especially erythroid changes, may be involved in acute mountain sickness (AMS) at high altitude. This study aimed to identify the relationship between excessive erythrocytosis and AMS following different durations of high-altitude exposure.

Methods: A total of 692 healthy young Chinese men were recruited for the study in June and July of 2012 and were divided into the following five groups: I) the 24-h group (24 hours after arrival at Lhasa, 3,700 m, n = 261); II) the 7-d group (exposed at Lhasa, 3,700 m for seven days, n = 99); III) the re-exposure group (re-exposed at Yang Bajing, 4,400 m for seven days after >1 year of acclimation at 3,700 m,n = 94); IV) the acclimated group (>1 year of acclimation at 3,700 m, Lhasa, n = 42); and V) the sea-level control (control group, Chengdu, n = 196).

Smoking is associated with the incidence of AMS: a large-sample cohort study.

Background: In recent years, the number of people visiting high altitudes has increased. After rapidly ascending to a high altitude, some of these individuals, who reside on plains or other areas of low altitude, have suffered from acute mountain sickness (AMS). Smoking interferes with the body's oxygen metabolism, but research about the relationship between smoking and AMS has yielded controversial results.

[The change of left ventricular function upon acute high altitude exposure and its relationship with acute mountain sickness].

Objective: To investigate the changes of the cardiac hemodynamics after acute high altitude exposure in healthy young males and the relationship with acute mountain sickness(AMS).

Methods: Left ventricular function and oxyhemoglobin saturation (SaO2), heart rate (HR), blood pressure (BP) were measured in 218 healthy young males before and after high altitude exposure within 24 h respectively. According to the lake louise score criteria, the subjects were divided into two groups: acute mountain sickness group (AMS group) and non acute mountain sickness group (non-AMS group).

Age as a risk factor for acute mountain sickness upon rapid ascent to 3,700 m among young adult Chinese men.

Background: The aim of this study was to explore the relationship between age and acute mountain sickness (AMS) when subjects are exposed suddenly to high altitude.

Methods: A total of 856 young adult men were recruited. Before and after acute altitude exposure, the Athens Insomnia Scale score (AISS) was used to evaluate the subjective sleep quality of subjects.

Sleep quality changes in insomniacs and non-insomniacs after acute altitude exposure and its relationship with acute mountain sickness.

Objective: We aimed to observe the changes in subjective sleep quality among insomniacs and non-insomniacs after acute ascending to 3,700 m and its possible relationship with acute mountain sickness (AMS).

Methods: A total of 600 adult men were recruited. Subjects' subjective sleep quality was evaluated by the Athens Insomnia Scale.

Cerebral hemodynamic characteristics of acute mountain sickness upon acute high-altitude exposure at 3,700 m in young Chinese men.

Purpose: We aimed at identifying the cerebral hemodynamic characteristics of acute mountain sickness (AMS).

Methods: Transcranial Doppler (TCD) sonography examinations were performed between 18 and 24 h after arrival at 3,700 m via plane from 500 m (n = 454). A subgroup of 151 subjects received TCD examinations at both altitudes.

Risk factors for high-altitude headache upon acute high-altitude exposure at 3700 m in young Chinese men: a cohort study.

Background: This prospective and observational study aimed to identify demographic, physiological and psychological risk factors associated with high-altitude headache (HAH) upon acute high-altitude exposure.

Methods: Eight hundred fifty subjects ascended by plane to 3700 m above Chengdu (500 m) over a period of two hours. Structured Case Report Form (CRF) questionnaires were used to record demographic information, physiological examinations, psychological scale, and symptoms including headache and insomnia a week before ascending and within 24 hours after arrival at 3700 m.

Anxiety correlates with somatic symptoms and sleep status at high altitudes.

High altitude exposure results in many physical and psychological discomforts, with anxiety and sleep disturbances being the most common ones. This cross-sectional study was performed to explore the relationship between anxiety, somatic symptoms, and sleep status at high altitude. A sample of 426 young males between 18 and 24 years old ascended from low-level land to 3600 m, where they acclimated for 40 days, before ascending to 4400 m.