Hypoxia or Oxygen deficiency, contributes significantly to the pathophysiology of many human diseases. High altitude is one such kind of environment where hypoxia is a major stress. The changes in the physiology at high altitude, whether short term or long term, help the successful survival of people from thousands of years. This suggests their adaptation to the adverse environment of high alti...

High altitude exposure results in decreased oxygen pressure and an increased formation of reactive oxygen and nitrogen species (RONS), which is often associated with increases in oxidative damage to lipids, proteins and DNA. Exposure to high altitude appears to decrease the activity and effectiveness of antioxidant enzymes system. Moreover, during high altitude exposure several RONS generating ...

Hypoxia is the main responsible factor initiating the symptoms of acute mountain sickness (AMS) in susceptible individuals. Measures that improve oxygenation and/or hasten acclimatization like pre-treatment with acetazolamide will prevent the development of AMS. We hypothesized that pre-treatment with acetazolamide the day before arrival at high altitude would elicit improved oxygenation compar...

Background: It is well recognized that a hypercoagulable state exists when a person is exposed to high altitude environment. This may manifest as early thromboembolic episodes, which result in acute pulmonary embolism. On further exposure to high-altitude environment, the ongoing thrombogenesis has been implicated in the causation of subacute mountain sickness. Only anecdotal reports of deep ve...

Running economy (RE) and VO2max are important predictors of endurance performance for elite and semi-elite endurance athletes, with RE being an appropriate predictor in a homogenous running population. Altitude training has been observed to change RE (mL.kg-1.min-1), and VO2max due to alterations resulting from acclimatization. This study tracked changes in RE and VO2max before and after a 10-d...

BACKGROUND Pulmonary hypertension is a hallmark of high-altitude pulmonary edema and may contribute to its pathogenesis. When administered by inhalation, nitric oxide, an endothelium-derived relaxing factor, attenuates the pulmonary vasoconstriction produced by short-term hypoxia. METHODS We studied the effects of inhaled nitric oxide on pulmonary-artery pressure and arterial oxygenation in 1...

To prepare for extremes of heat, cold or low partial pressures of oxygen (O2), humans can undertake a period of acclimation or acclimatization to induce environment-specific adaptations, e.g. heat acclimation (HA), cold acclimation (CA), or altitude training. While these strategies are effective, they are not always feasible due to logistical impracticalities. Cross-adaptation is a term used to...

Hypoxia inducible factors, including HIF1A and HIF2A, play central roles in response to high-altitude hypoxia and genetic variants of HIF1A or HIF2A were associated with high-altitude sickness or adaptation. However, it remains to determine whether they are associated with tolerance to different levels of high-altitude selection pressure among native Tibetans. We recruited 189 Tibetan subjects ...

Hypoxia impairs metabolic functions by decreasing activity and expression of ATP-consuming processes. To separate hypoxia from systemic effects, we tested whether hypoxia at high altitude affects basal and PMA-stimulated leukocyte metabolism and how this compares to acute (15 min) and 24 h of in vitro hypoxia. Leukocytes were prepared at low altitude and ∼24 h after arrival at 4559 m. Mitochond...

BACKGROUND Altitude exposure causes acute sleep disruption in non-athletes, but little is known about its effects in elite athletes. The aim of this study was to examine the effects of altitude on two groups of elite athletes, that is, sea-level natives and high-altitude natives. METHODS Sea-level natives were members of the Australian under-17 soccer team (n=14). High-altitude natives were m...