Fluctuations in autonomic cardiovascular regulation during exposure to high altitude may increase the risk of heart attack during waking and sleep. This study compared heart rate variability (HVR) and its components during sleep at low altitude and after 30 41 hours of acclimatization at high altitude (3480 m) in five mountain marathon runners controlled for diet, drugs, light-dark cycle and je...

Acute mountain sickness is the commonest acute high altitude illness occurring at high altitude. Its prevalence is dependent on the ascent rate, altitude achieved, physical effort required to reach the target altitude and pharmacological intervention undertaken by the tourists visiting high altitude areas. This Letter to the Editor is an endeavour to re-emphasise the importance of all these fac...

BACKGROUND AND PURPOSE Andean highlanders, unlike Ethiopians, develop chronic mountain sickness (CMS), a maladaptation to their native land. Ambient hypoxia induces NO-mediated vasodilatation. Fitness for life at altitude might be revealed by cerebrovascular responses to NO. METHODS Nine altitude-native men were examined at 3622 and 794 m in Ethiopia and compared with 9 altitude-native Andean...

Effects of high altitude hypoxia on systolic time intervals were examined in 34 healthy men: 20 sea level residents studied at rest and at the end of 3 minutes steady isometric (handgrip) exercise at sea level and then serially for the first 5 days and on the tenth day, at an altitude of 3658 m, and I4 permanent residents at high altitude studied at high altitude. In the sea level residents the...

OBJECTIVES Inter-individual variations in sea level performance after altitude training have been attributed, at least in part, to an inter-individual variability in hypoxia induced erythropoiesis. The aim of the present study was to examine whether the variability in the increase in total haemoglobin mass after training at moderate altitude could be predicted by the erythropoietin response aft...

High-altitude destinations are visited by increasing numbers of children and adolescents. High-altitude hypoxia triggers pulmonary hypertension that in turn may have adverse effects on cardiac function and may induce life-threatening high-altitude pulmonary edema (HAPE), but there are limited data in this young population. We, therefore, assessed in 118 nonacclimatized healthy children and adol...

Nepal, the home of the highest mountain peaks, is one of the most popular trekking destinations in the world. The Himalaya begins where other mountain ranges leave off. Local farmers have cut small terrace fields on the slopes of colossal gorges which have been carved out by large glacial fed rivers. Everest Base Camp located at an altitude of 5,360 metres (17,590 ft) is 1,000 meters higher tha...

Suicide, the tenth leading cause of death worldwide, is a complex phenomenon. Models aiming to explain the interaction of ambient variables such as socioeconomic factors, lithium content of drinking water and altitude are poorly developed. While controlling for several risk factors, this research bridges two different, but complementary research lines by investigating statistically the relation...

Exposure to high altitude, which is associated with decreased oxygen pressure, could result in oxidative/reductive stress, enhanced generation of reactive oxygen and nitrogen species (RONS), and related oxidative damage to lipids, proteins, and DNA. The severity of oxidative challenge is related to the degree of altitude. A wide range of RONS generating systems are activated during exposure to ...

Methods for measuring the ventilatory response to hypoxia (HVR) are reviewed. The criteria for success as a high altitude mountaineer are defined as freedom from acute mountain sickness (AMS) and ability to perform well at extreme altitude. The evidence for a brisk HVR being protective against AMS and associated with successful high altitude performance is reviewed. The contrary evidence of blu...