Hypoxia at high altitudes is often assumed to constrain exercise capacity, but there have been few high- versus low-altitude comparisons of species native to a wide range of altitudes. Such studies are ecologically realistic, as wild-caught animals tested at their native altitude are presumably maximally acclimated (via phenotypic plasticity) or adapted (by evolutionary change) to that altitude...

BACKGROUND This study aimed to quantify structural and functional changes at the macula during acute exposure to high altitude and to assess their structure/function relationship. This work is related to the Tuebingen High Altitude Ophthalmology (THAO) study. METHODOLOGY/PRINCIPAL FINDINGS Spectral domain optical coherence tomography and microperimetry were used to quantify changes of central...

The authors analyzed refractive results of patients who underwent radial keratotomy (RK) at sea level and high altitude and evaluated the effects of the altitude. A total of 102 eyes undergoing RK procedures performed in two clinical centers having different altitude were analyzed. The results compared between subjects who had undergone RK at sea level (Istanbul/Turkey) and at an altitude of 57...

BACKGROUND Due to increasing numbers of people with diabetes taking part in extreme sports (e.g., high-altitude trekking), reliable handheld blood glucose meters (BGMs) are necessary. Accurate blood glucose measurement under extreme conditions is paramount for safe recreation at altitude. Prior studies reported bias in blood glucose measurements using different BGMs at high altitude. We hypothe...

BACKGROUND Previous studies on ventilators used for air transport showed significant effects of altitude, in particular with regard to accuracy of the tidal volume (VT) and breathing frequency. The aim of the study was to evaluate transport ventilators under hypobaric conditions. METHODS We conducted a bench study of 6 transport ventilators in a Comex hypobaric chamber to simulate mild altitu...

We have previously documented the importance of the sympathetic nervous system in acclimatizing to high altitude in men. The purpose of this investigation was to determine the extent to which alpha-adrenergic blockade affects the sympathoadrenal responses to exercise during acute high-altitude exposure in women. Twelve eumenorrheic women (24.7 +/- 1.3 yr, 70.6 +/- 2.6 kg) were studied at sea le...

BACKGROUND High altitude disease (HAD) can reduce combat effectiveness and damage the health of soldiers at high altitudes. The objective of this hypothesis study is to build a four-period prevention model for high altitude disease that can be applied at high altitudes of over 3000 m. PRESENTATION OF THE HYPOTHESIS We divided the time at high altitude into nine periods, with three stages from...

Background: Chronic asthma is a common, obstructive lung disease, affecting 300 million people worldwide. In the past 30 years prevalence has increased. Control of asthma is currently achieved with pharmacotherapeutic interventions such as inhaled sympathicomimetics and glucocorticocoids. High altitude climate therapy is an alternative method to pharmacological treatment. In the age before anti...

BACKGROUND Altitude illness is a relevant threat to the life and health of participants in mountaineering expeditions. AIM To determine if impedance cardiography (ICG) can be used in noninvasive monitoring of haemodynamic disturbances at high altitude. METHODS The study was performed in a group of 13 participants of two mountaineering expeditions in the Himalayas. The ICG examination was pe...

introduction: chronic mountain sickness (cms) represents a syndrome of secondary polycythemia along with thrombocytopenia, altered hemorheology, pulmonary and systemic hypertension, and congestive heart failure, occurring due to hypobaric hypoxia-anoxia-induced erythropoiesis reported in both native mountain residents and new climbers after prolonged stays at high and extreme altitudes.case pre...