High Altitude Mountaineering Research Articles

Hypoxia impairs adaptation of skeletal muscle protein turnover- and AMPK signaling during fasting-induced muscle atrophy

BackgroundHypoxemia in humans may occur during high altitude mountaineering and in patients suffering from ventilatory insufficiencies such as cardiovascular- or respiratory disease including Chronic Obstructive Pulmonary Disease (COPD). In these conditions, hypoxemia has been correlated to reduced appetite and decreased food intake. Since hypoxemia and reduced food intake intersect in various physiological and pathological conditions and both induce loss of muscle mass, we investigated whether hypoxia aggravates fasting-induced skeletal muscle atrophy and evaluated underlying protein turnover signaling.MethodsMice were kept under hypoxic (8% oxygen) or normoxic conditions (21% oxygen), or were pair-fed to the hypoxia group for 12 days. Following an additional 24 hours of fasting, muscle weight and protein turnover signaling were assessed in the gastrocnemius muscle by RT-qPCR and Western blotting.ResultsLoss of gastrocnemius muscle mass in response to fasting in the hypoxic group was increased compared to the normoxic group, but not to the pair-fed normoxic control group. Conversely, the fasting-induced increase in poly-ubiquitin conjugation, and expression of the ubiquitin 26S-proteasome E3 ligases, autophagy-lysosomal degradation-related mRNA transcripts and proteins, and markers of the integrated stress response (ISR), were attenuated in the hypoxia group compared to the pair-fed group. Mammalian target of rapamycin complex 1 (mTORC1) downstream signaling was reduced by fasting under normoxic conditions, but sustained under hypoxic conditions. Activation of AMP-activated protein kinase (AMPK) / tuberous sclerosis complex 2 (TSC2) signaling by fasting was absent, in line with retained mTORC1 activity under hypoxic conditions. Similarly, hypoxia suppressed AMPK-mediated glucocorticoid receptor (GR) signaling following fasting, which corresponded with blunted proteolytic signaling responses.ConclusionsHypoxia aggravates fasting-induced muscle wasting, and suppresses AMPK and ISR activation. Altered AMPK-mediated regulation of mTORC1 and GR may underlie aberrant protein turnover signaling and affect muscle atrophy responses in hypoxic skeletal muscle.

Grenzen im Aufstieg. Berge als Transgressionsräume von Geschlechtergrenzen

ASCENTS WITH LIMITS: MOUNTAINS AS SPACES FOR GENDER TRANSGRESSIONMountains and Alpine spaces are historical places where determined national, economic and cultural norms as well as practices were and still are negotiated. The article focuses on the question of gender in the mountains as a social space, which the author explores, drawing on the example of the history of climbing expeditions to the highest mountains in the world, the Himalayas. Against this background she presents, from the point of view of gender history, the so-called female expeditions, i.e. mountain expeditions initiated, organised and conducted from the mid-1950s by all-female teams. They serve as analytical lenses to look into gender relations in mountaineering and their transformations in 1955–2014. Drawing on four social spaces the author raises questions about crossing gender boundaries due to socially-constructed gender norms as well as strategies for overcoming them.The first part of the article is devoted to female expeditions undertaken in 1955–1962 by British female climbers. These enterprises expanded the areas in which female mountaineers operated, without, however, questioning social gender stereotypes. The organisers of the expeditions deliberately presented themselves in accordance with social gender norms, and by choosing reasonable mountain goals, didn’t join the competition associated with the Himalayan eight-thousanders. The importance of gender based boundaries in high altitude mountaineering in the late 1950s is revealed in part two of the article when for the first time a female team set a famous eight-thousander as a goal for themselves. Press reports from before and after the expedition reflect prejudice and scepticism, presenting the female climbers in a manner that affronted them as overambitious and incompetent. It was not until the 1970s that a younger generation of female climbers openly and critically spoke against sexism and discrimination of women in high mountain climbing, as the author describes in part three. Female expeditions allowed women to avoid exclusion from male teams and attempt to climb the highest peaks on their own. The article ends with a presentation of the significance of female expeditions in the Himalayan state of Nepal, where since the 1990s such expeditions have provided Nepalese women with opportunities to made their mark on the tourist trade. On the other hand, female expeditions have been used by tourist and political institutions as an instrument of raising public awareness of issues like equality policy, climate protection or promotion of tourism.

Granice we wspinaniu. Góry jako przestrzenie transgresji granic płci

ASCENTS WITH LIMITS: MOUNTAINS AS SPACES FOR GENDER TRANSGRESSIONMountains and Alpine spaces are historical places where determined national, economic and cultural norms as well as practices were and still are negotiated. The article focuses on the question of gender in the mountains as a social space, which the author explores, drawing on the example of the history of climbing expeditions to the highest mountains in the world, the Himalayas. Against this background she presents, from the point of view of gender history, the so-called female expeditions, i.e. mountain expeditions initiated, organised and conducted from the mid-1950s by all-female teams. They serve as analytical lenses to look into gender relations in mountaineering and their transformations in 1955–2014. Drawing on four social spaces the author raises questions about crossing gender boundaries due to socially-constructed gender norms as well as strategies for overcoming them.The first part of the article is devoted to female expeditions undertaken in 1955–1962 by British female climbers. These enterprises expanded the areas in which female mountaineers operated, without, however, questioning social gender stereotypes. The organisers of the expeditions deliberately presented themselves in accordance with social gender norms, and by choosing reasonable mountain goals, didn’t join the competition associated with the Himalayan eight-thousanders. The importance of gender based boundaries in high altitude mountaineering in the late 1950s is revealed in part two of the article when for the first time a female team set a famous eight-thousander as a goal for themselves. Press reports from before and after the expedition reflect prejudice and scepticism, presenting the female climbers in a manner that affronted them as overambitious and incompetent. It was not until the 1970s that a younger generation of female climbers openly and critically spoke against sexism and discrimination of women in high mountain climbing, as the author describes in part three. Female expeditions allowed women to avoid exclusion from male teams and attempt to climb the highest peaks on their own. The article ends with a presentation of the significance of female expeditions in the Himalayan state of Nepal, where since the 1990s such expeditions have provided Nepalese women with opportunities to made their mark on the tourist trade. On the other hand, female expeditions have been used by tourist and political institutions as an instrument of raising public awareness of issues like equality policy, climate protection or promotion of tourism.

High-Altitude Illness Death Investigation.

High altitude illness (HAI) is the current accepted clinical term for a group of disorders including acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE), which occur in travelers visiting high-altitude locations. High-altitude illness is due to hypobaric hypoxia, is not associated with age or physical conditioning, and mild forms are easily treated. High-altitude cerebral edema and HAPE are medical emergencies that are fatal if not promptly treated and fortunately are uncommon. The cause of most high-altitude fatalities is not related to HAI and can be easily distinguished from HACE and HAPE; however, other causes of death may have symptoms and physical findings that overlap with HAI, making postmortem diagnosis challenging. Fatalities due to HAPE and HACE are diagnoses of exclusion. Medical examiners and coroners who work in jurisdictions with high-altitude locations should be aware of the risk factors, physiology, pathology, differential diagnosis, and classification of HAI to accurately recognize HAI as a cause of death. Medical examiners who do not work in jurisdictions with high-altitude locations may be asked to evaluate deaths that occur overseas associated with high-altitude trekking and mountaineering activities.

‘Endurance Work’: Embodiment and the Mind–Body Nexus in the Physical Culture of High-Altitude Mountaineering

The 2015 Nepal earthquake and avalanche on Mount Everest generated one of the deadliest mountaineering disasters in modern times, bringing to media attention the physical-cultural world of high-altitude climbing. Contributing to the current sociological concern with embodiment, here we investigate the lived experience and social ‘production’ of endurance in this sociologically under-researched physical-cultural world. Via a phenomenological-sociological framework, we analyse endurance as cognitively, corporeally and interactionally lived and communicated, in the form of ‘endurance work’. Data emanate from in-depth interviews with 18 high-altitude mountaineers, 10 of whom experienced the 2015 avalanche. The article responds to Shilling’s call to address an important lacuna identified in sociological work: the need to investigate the embodied importance of cognition in the incorporation of culture. The concept of endurance work provides a powerful exemplar of this cognitive–corporeal nexus at work as a physical-culturally shaped, embodied practice and mode-of-thinking in the social world of high-altitude climbing.

Circle (CO2 reabsorbing) breathing systems: Human applications.

Artificial breathing systems to help humans survive extreme environments are used over a range of ambient pressures, using various gases of different volumetric concentrations. These activities include anaesthesia and intensive care activity, high-altitude mountaineering, firefighting, aerospace extravehicular space activity and underwater diving operations. A circle breathing system is one in which the exhaled carbon dioxide is absorbed by an alkali substance and the remaining unused gases are recirculated, usually for the sake of economy and environment. This allows the flow of the fresh gas to be considerably reduced, thereby saving on fresh-gas supply. Circle systems are often used in the circumstances cited above, although not always at low fresh-gas flows. The circle system used in anaesthesia and intensive care has the least engineering demands made on it, although it is used on patients who are highly vulnerable; it usually provides a mixture of air and oxygen, and perhaps a breathable anaesthetic gas, all at sea-level pressure. Mountaineering and firefighting applications involve an extreme earthbound environment, with the user undergoing extreme physical work. The astronaut's spacesuit and life support system contains a high-flow circle system, the breathing gases themselves pressurising the suit as well as providing respiratory life support and thermal comfort; the gas provided is pure oxygen at about a third of sea-level atmosphere. There are numerous varieties of breathing systems for diving, including a circle system, often for clandestine naval activity; the gases used are a combination of oxygen, nitrogen and helium, to minimise the possibility of decompression sickness, nitrogen narcosis and oxygen toxicity and must be provided at a varying pressure and concentration appropriate to depth.

Hydration Status as a Predictor of High-altitude Mountaineering Performance

Background: Hydration status is a controversial determinant of athletic performance. This relationship has not been examined with mountaineering performance.Methods: This was a prospective observational study of mountaineers who attempted to climb Denali in Alaska. Participants’ urine specific gravity (SG), and ultrasound measurements of the inferior vena cava size and collapsibility index (IVC-CI) were measured at rest prior to ascent. Upon descent, climbers reported maximum elevation gained for determination of summit success.Results: One hundred twenty-one participants enrolled in the study. Data were collected on 111 participants (92% response rate); of those, 105 (87%) had complete hydration data. Fifty-seven percent of study participants were found to be dehydrated by IVC-CI on ultrasound, and 55% by urine SG. No significant association was found with summit success and quantitative measurements of hydration: IVC-CI (50.4% +/- 15.6 vs. 52.9% +/- 15.4, p = 0.91), IVC size (0.96 cm +/- 0.3 vs. 0.99 cm +/- 0.3, p = 0.81), and average SG (1.02 +/- 0.008 vs. 1.02 +/- 0.008, p = 0.87). Categorical measurements of urine SG found 24% more successful summiters were hydrated at 14 Camp, but this was not found to be statistically significant (p = 0.56). Summit success was associated with greater water-carrying capacity on univariate analysis only: 2.3 L, 95% confidence interval (2.1 – 2.5) vs. 2.1 L, 95% confidence interval (2 – 2.2); p < 0.01.Conclusions: Intravascular dehydration was found in approximately half of technical high-altitude mountaineers. Hydration status was not significantly associated with summit success, but increased water-carrying capacity may be an easy and inexpensive educational intervention to improve performance.

Toward a Structural Model of Challenge Experience in Adventure Recreation

Perceiving challenge is an important aspect of adventure recreation. Yet few studies have considered the potential outcome of challenge perception among participants in adventure recreation. This study seeks to address this by establishing a comprehensive model of challenge perception in adventure recreation that additionally models the relationship between challenge and its outcome. A self-administered questionnaire is designed to collect empirical data from recreationists who engaged in scuba diving, high-altitude mountaineering, or white-water rafting in Taiwan. Using a structural equation modeling approach, the findings indicate that perception of challenge among recreationists has a positive impact on flow experience and, by extension, on satisfaction, and psychological well-being.

Human Factors in High-Altitude Mountaineering

We describe the human performance and cognitive challenges of high altitude mountaineering. The physical (environmental) and internal (health) stresses are first described, followed by the motivational factors that lead people to climb. The statistics of mountaineering accidents in the Himalayas and Alaska are then described. We then present a detailed discussion of the role of decision-making biases in mountaineering mishaps. We conclude by discussing interpersonal factors, adaptation, and training issues.

Climbing Beyond the Summits: Social and Global Aspects of Women's Expeditions in the Himalayas

This article investigates the conditions and circumstances that led to the emergence of Nepalese women's mountaineering. It draws a comparison and shows parallels with the development of Western female mountaineering. The special focus here is on so-called ‘women's expeditions’ in the Himalayas. In the last 20 years, these expeditions have played an important role for Nepalese women in gaining access to high-altitude climbing. An overview of the historical developments from the 1950s to the present illustrates the transnational and global involvement of high-altitude mountaineering in Nepal, as well as the impact of political and social programmes to foster gender equality and diversity.

High-altitude mountaineering made safer

Mountains all over the world are attracting a steadily growing number of visitors due to the increasing number of cheap flights; the construction of new roads, railways, and cable cars; and commercial offers of trekking tours and expeditions to attempt even the world's highest peaks. However, one must not forget that mountains are typically inhospitable areas characterised by cold and hypoxic environments and rapidly changing weather and track conditions associated with a relatively high risk of accidents and emergencies. Beside the objective hazards, subjective hazards, for example physical fitness and health status, mountaineering skills, and equipment, contribute substantially to the risk. Whereas in some regions, for example the Alps, rescue operations and medical emergency interventions can be performed rapidly and effectively, this is absolutely not the case in most of the very remote areas and on very high mountains. Therefore, the understanding of the risk associated with the various modes of mountaineering as well as knowledge about how to optimise prevention is of the utmost importance. Ultimately, it is the informed mountaineer who has to decide whether the risks are acceptable or not. Continuing joint efforts of scientists, medical and alpine institutions, expedition organisers, and mountaineers will help to make high-altitude mountaineering safer.

Intrinsic motivation, vitality, and high altitude mountaineering: Analysis of seven case studies

For outdoor leaders, understanding psycho-physiological factors can provide insight into college students' performance while on a mountaineering expedition involving exposure to high altitude (5640 m). This paper focuses on each participant's level of intrinsic motivation (IM), subjective vitality (SV), select physiological markers, and the presences of acute mountain sickness (AMS) based on the specified mountaineering context and altitude, through Cognitive Evaluation Theory, a sub-theory of Self-determination Theory. A multiple case study design (N=7) was employed; data were collected at select times during the expedition. Case's results reflect a sharp decline in SV level before descending, and similarly for IM with noted exceptions. IM and SV scores may have been a function of the physiological changes that occurred during high altitude exposure. Employing a deliberate participant data observation system in the field can improve leaders' understanding of participant's psycho-physiological status.

高所登山は「死と隣り合わせ」か：高所登山家のリスクの捉えとリスク対処方略を明らかにする

Perception and management of risk by high altitude mountain climbers were investigated by qualitative analysis. Reports of high altitude mountain climbing collected from 3 books and 15 articles from mountaineering magazines were analyzed by the KJ method and transcripts derived from semi-structured interview of 6 distinguished Japanese expert mountain climbers were analyzed by M-GTA. The results indicated the following trends: 1) The desire for more fascinating high altitude mountain climbing routes inevitably leads climbers to face difficult and uncertain situations. 2) Such climbers are highly aware of the uncertainty derived from the high altitude environment and the exertion of climbing. 3) Because they are aware of this uncertainty, their decisions always waver between challenge and safety, and they always attempt to reduce the degree of risk. 4) Such efforts consist of two phases: risk reduction prior to the climb, and on-site avoidance of risk, each being characterized by mental simulation, avoidance of uncontrollable situations, and endeavours to salvage a positive result. 5) After the climb, ambivalent cognition between reflection on their optimism and achievement also emerges. Among all, mental simulation primed by on-site signs of risk, and risk evaluation from the viewpoint of controllability were regarded as keys to staying alive in high risk situations during high altitude mountaineering. Through this risk perception and management process, high altitude climbers possess a contradictory sense of “controllable risk” that enables them to engage in high risk activity. Overall, the characteristics of risk perception and management were similar among the materials obtained from books/magazine articles and interview transcripts. The characteristics of climbers' perception and risk management were rationalized by the characteristics of the natural environment in which they were climbing, and also from the viewpoint of the situated action. The possible application of these findings to risk management in outdoor sports was also discussed.

Fatalities in High Altitude Mountaineering: A Review of Quantitative Risk Estimates

Quantitative estimates for mortality in high altitude mountaineering are reviewed. Special emphasis is placed on the heterogeneity of the risk estimates and on confounding. Crude estimates for mortality are on the order of 1/1000 to 40/1000 persons above base camp, for both expedition members and high altitude porters. High altitude porters have mostly a lower risk than expedition members (risk ratio for all Nepalese peaks requiring an expedition permit: 0.73; 95 % confidence interval 0.59-0.89). The summit bid is generally the most dangerous part of an expedition for members, whereas most high altitude porters die during route preparation. On 8000 m peaks, the mortality during descent from summit varies between 4/1000 and 134/1000 summiteers (members plus porters). The risk estimates are confounded by human and environmental factors. Information on confounding by gender and age is contradictory and requires further work. There are indications for safety segregation of men and women, with women being more risk averse than men. Citizenship appears to be a significant confounder. Prior high altitude mountaineering experience in Nepal has no protective effect. Commercial expeditions in the Nepalese Himalayas have a lower mortality than traditional expeditions, though after controlling for confounding, the difference is not statistically significant. The overall mortality is increasing with increasing peak altitude for expedition members but not for high altitude porters. In the Nepalese Himalayas and in Alaska, a significant decrease of mortality with calendar year was observed. A few suggestions for further work are made at the end of the article.

Mountaineering Fatalities on Aconcagua: 2001–2012

High altitude mountaineering is a dangerous endeavor due to the hypoxic hypobaric environment, extreme weather, and technical skills required. One of the seven summits, Aconcagua (6962 m) is the highest mountain outside of Asia. Its most popular route is nontechnical, attracting >3000 mountaineers annually. Utilizing data from the Servicio Médico Aconcagua (park medical service), we performed a retrospective descriptive analysis with the primary objective of deriving a fatality rate on Aconcagua from 2001 to 2012. The fatality rate on Aconcagua was then compared to other popular mountains. For climbers who died, we report all available demographic data, mechanisms of death, and circumstances surrounding the death. Between 2001 and 2012, 42,731 mountaineers attempted to summit Aconcagua. There were 33 fatalities. The fatality rate was 0.77 per 1000, or 0.077%. The fatality rate on Aconcagua is lower than that on Everest or Denali but higher than that on Rainier.

Intrinsic motivation, vitality, and high altitude mountaineering: An analysis of seven case studies

College adventure leadership programs may involve training students through multi-day expeditions to remote locations to test their physical and psychological performance. In the context of a group-oriented, mountaineering course in a high altitude environment participant's performance level might be a function of motivation level, vitality level, and/or may be influenced by physiological changes occurring during the ascent. The theoretical framework selected for the study was Cognitive Evaluation Theory (CET) (Deci &amp; Ryan, 1985b), a sub-theory of Selfdetermination Theory (SDT) (Deci &amp; Ryan, 1985a). CET suggests that an intrinsically motivated activity, if internalized, could be a representation of a participant's inclination to be physically active and to expand his or her capacities and abilities. For mountaineers participating on an expedition, those with higher levels of intrinsic motivation might somewhat influence performance, the level of challenge accepted, or willingness to push through adversity toward achievement of an internalized external goal.

The Dark Side of Adventure: Exploring the Stress-Coping Strategies of Mountaineers’ Significant Others Regarding High Altitude Mountaineering Expeditions

Since their inception in the 1920s, high altitude mountaineering expeditions (HAMEs) have been the center of many adventure stories. Despite the high risk of HAMEs, mountaineers have often been portrayed as heroes by mass media and literature. The thrill-seeking behaviors of mountaineers usually result in positive psychological benefits, and few arguments have suggested that such action can harm the mountaineers involved or negatively affect others. However, no empirical study has examined the direct impact on the significant others of mountaineers when they participate in HAMEs. This study addresses this imbalance by examining the stresses caused by a Taiwanese HAME and how the significant others of mountaineers cope with HAME-related stressors. This paper explores this overlooked experience by interviewing three significant others of mountaineers of a particular expedition. The findings indicate that the significant others of mountaineers experience various levels of stressors, such as emotional burdens associated with long separation and fear of bereavement, which are often found among military deployment families. In addition, the results suggest that a range of internal and external stress-coping strategies such as denial, religion, self-care, and technology are used to overcome these hurdles successfully. Numerous suggestions for improved adaptation by the significant others of HAME mountaineers are also identified. This research advocates more effective support for the quality of life of these significant others and suggests that mountaineers work alongside their loved ones as they pursue HAMEs. Finally, potential avenues for future research on this topic are considered.

Endeavour, altitude and risk: reflections on a lifetime of mountaineering and exploration

In July 2012 thousands of competitors from many nations arrive for the London Olympics, each striving to be a champion. Oh, the drive, resolve, heartache and pain. Our capital will be taken over, the press will both celebrate and criticize events; sponsorship deals will soon dominate the results. The men and women who are competing will have trained for many months or years, striven nationally and internationally, fighting hard for places in their teams. What drives them? This short paper is a personal perspective, unashamedly anecdotal, looking at some of the driving forces behind my own endeavours. I have spent a lifetime climbing mountains, with a focus on the exploration of remote regions. I also deal here with the physiological and medical challenges that high altitude mountaineering poses, and discuss its risks.

Health risk for athletes at moderate altitude and normobaric hypoxia

Altitudes at which athletes compete or train do usually not exceed 2000–2500 m. At these moderate altitudes acute mountain sickness (AMS) is mild, transient and affects at the most 25%...

Targeting Hypoxia-induced Inflammation

In the current issue of Anesthesiology, a paper by Kim et al. from the research laboratory of Dr. H. Thomas Lee investigates strategies to dampen ischemia-driven inflammation of the kidneys and subsequent multi-organ failure utilizing experimental models of acute kidney injury (AKI).1 In fact, one of the leading causes of morbidity and mortality in surgical patients is perioperative organ failure, such as occurs in the context of acute kidney injury, liver failure, intestinal or myocardial ischemia, stroke or acute lung injury. A common feature of these perioperative diseases is the presence of hypoxia-induced inflammation.2,3 The relationship between hypoxia and inflammation under these conditions is inter-dependent. For example, exposure to ambient hypoxia - as seen during high-altitude mountaineering - is associated with edema of the lungs or the brain, and systemic inflammatory responses in humans.4,5 Similarly, acute exposure of mice to ambient hypoxia (e.g. 8% of oxygen over 4–8h) leads to increased inflammatory cytokine levels and pulmonary edema.6 Moreover, prolonged donor organ exposure to ischemia during organ transplantation is known to enhance graft inflammation and early graft failure.7,8 For example, the endotoxin-receptor TLR4 is expressed in the donor kidney during kidney transplantation, and TLR4 expression levels increase with prolonged ischemia time. Donor kidneys with a loss-of-function mutation of the TLR4 receptor show attenuated kidney inflammation, and an increased rate of immediate graft function.7 Together, these studies indicate that hypoxia represents an inflammatory stimulus (Figure 1) and suggest that targeting hypoxia-elicited inflammation could represent an important therapeutic approach in perioperative medicine.