magazine_ Article

To K2!

A project by Eurac Research is investigating the physiology of eight female mountaineers on their way to climb the second highest mountain on Earth


Mountaineer Silvia Loreggian undergoes one of the medical tests aimed at examining her physiological response to high altitude.

© Eurac Research | Andrea De Giovanni

Andrea De Giovanni
by Andrea De Giovanni

Seventy years after its first summiting, an equally divided cohort of eight female mountaineers from Italy and Pakistan, will attempt to climb the world's second highest peak: K2. The initiative, sponsored by the Italian Alpine Club, involves Eurac Research’s Institute for Mountain Emergency Medicine. The mountaineers underwent a series of preliminary tests at our extreme environment simulator – terraXcube. Once their adventure is over, they will return to undergo more tests in the unique infrastructure. The research mission: study female physiology before and after exposure to high altitude.

With the exception of some populations, humans are not adapted to live above a certain altitude. The reduction in air pressure that takes place as altitude increases makes it increasingly difficult to oxygenate the blood and, consequently, other body tissues.

High altitude and hypoxia

The air above us exerts a certain level of atmospheric pressure on every surface it contacts. As we rise in altitude, the amount of air bearing down on us decreases, and with it, atmospheric pressure also decreases, as does the pressure exerted by each of the gases in the air itself. Among these gases is oxygen. At the summit of Mont Blanc – 4,807 m.a.s.l, the partial pressure of oxygen is little more than half that found at sea level. Above 8,000 m.a.s.l, one enters the so-called “death zone” where the partial pressure of oxygen is so low that it would be impossible to survive for more than a few hours. The lower the oxygen pressure in the air, in fact, the more difficult it will be to pass into the blood from the lungs. Poor oxygenation of the blood results in poor oxygenation of other tissues, a condition known as hypoxia.

Oxygen deficiency triggers several physiological responses, including increased heart and respiratory rates, dilation of cerebral and muscular blood vessels, and constriction of pulmonary blood vessels. While these physiological changes temporarily make up for the lack of oxygen in the tissues, they also underlie the symptoms of acute mountain sickness. Being at high altitude without having acclimatized first, that is, without having given the body time to adapt to hypoxia, can result in headaches, nausea, insomnia, sleep apnea, even, in severe cases, hallucinations, and pulmonary and cerebral edema.

Much of what is known about the effects of high altitude on the human body comes from studies conducted on male subjects.

Much of what is known about the effects of high altitude on the human body comes from studies conducted on male subjects. The paucity of data on female physiology at high altitudes is not only surprising, considering that women have been climbing mountains since the advent of modern mountaineering, but also dangerous: having such little data means that ad hoc medical recommendations for female mountaineers are likely to be unreliable. In light of this, the women’s ascent of K2, organized by the Italian Alpine Club on the 70th anniversary of the summit’s conquest, presents a golden opportunity.

The women’s ascent of K2 presents a golden opportunity.

Apart from being the second highest peak in the world, K2 is considered the most difficult mountain to climb. The reason lies in its 8,611-meter height, combined with the extreme steepness of its slopes.
alt© Eurac Research | Andrea De Giovanni
Anna Torretta being interviewed immediately after the press conference held at the terraXcube to present the research project on women’s physiology at extreme altitudes. The mountaineer is one of eight women who will climb K2 in July.

Before their expedition, the eight Italian and Pakistani mountaineers stopped by terraXcube where, under the guidance of researchers from Eurac Research’s Institute for Mountain Emergency Medicine, CeRiSM – the Sport, Mountain and Health Research Center in Rovereto –, Italian Alpine Club and Institute of Clinical Physiology, the group underwent a series of tests. These were carried out both at Bolzano’s altitude and at the simulated altitude of 5,000 m.a.s.l: the same altitude at which the K2 base camp is located. Among the examinations performed, various blood samples, tests and analyses designed to assess cardiovascular and respiratory function both at rest and during exercise, such as ultrasound scans and spirometry, and brain function, as well as computer-based cognitive tests were carried out on the female subjects. The latter took into account reaction speed, short-term memory, and the ability to process visual-spatial information.

alt© Eurac Research | Andrea De Giovanni
The eight mountaineers who will climb K2 in July underwent a series of examinations and tests, performed both at the same altitude in Bolzano and at the simulated altitude of 5,000 m.a.s.l. In this photo, Cristina Piolini undergoes an objective examination aimed at assessing her overall health status.
alt© Eurac Research | Andrea De Giovanni
Ultrasound of neck blood vessels, performed on Silvia Loreggian, to quantify blood flow reaching the brain. In hypoxia, cerebral blood flow increases, compensating for the lack of oxygen. However, at the same time, this causes the brain to swell slightly. It is this phenomenon that is responsible for the headache typical of mountain sickness.
alt© Eurac Research | Andrea De Giovanni
Ultrasound of blood vessels performed on Federica Mingolla. Using the ultrasound scanner, it is possible to estimate the velocity of the blood and the diameter of the blood vessels. Using these two parameters, it is possible to calculate how much direct blood flow to the brain there is.
alt© Eurac Research | Andrea De Giovanni
Measurement of cerebral blood flow at the level of arteries located inside the skull.
alt© Eurac Research | Andrea De Giovanni
By resting the ultrasound probe on the eyeball, the diameter of the optic nerve, an indicator of intracranial pressure can be measured: the more the brain is swollen with blood and fluid, the greater the pressure it exerts on the skull and, the greater the diameter of the optic nerve.
alt© Eurac Research | Andrea De Giovanni
Lung ultrasound performed to detect the possible presence of pulmonary edema. In hypoxia, the capillaries of the pulmonary arteries narrow. This physiological response, present in humans from fetal life, reduces blood flow to areas of the lung that are poorly oxygenated, directing it to those that are more so. At the same time, however, narrowing of the pulmonary blood vessels causes an increase in the blood pressure within them. This increase in blood pressure in turn causes blood plasma to leak from the capillaries. Edema is when the plasma accumulates in the spaces between cells or in the pulmonary alveoli. Edema reduces lung function further and, in severe cases, can lead to death.
alt© Eurac Research | Andrea De Giovanni
A strain gauge records microscopic deformations of the skull caused by blood flow to the brain. Whenever the pressure wave generated by a heartbeat reaches the brain, the blood causes slight expansions of the skull, which this innovative instrument detects.
alt© Eurac Research | Andrea De Giovanni
Like a kind of seismograph, this mechanical strain gauge detects the deformations produced by blood pressure on the cranial box. From the magnitude and appearance of these deformations, intracranial pressure can be estimated.
alt© Eurac Research | Andrea De Giovanni
Silvia Loreggian undergoes a test to evaluate cardiorespiratory responses whilst on a cycle ergometer. During this test, the heart’s activity is monitored using heart rate and blood pressure and with an electrocardiogram. At the same time, the face mask is connected to a turbine that quantifies the volume of inhaled and exhaled air. The mask is also connected to sensor that measures the percentage of carbon dioxide and oxygen . By comparing the percentage of oxygen inhaled with that exhaled, the amount of oxygen that reaches the muscles and is consumed is traced back. Finally, oxygenation of the muscles is measured through an infrared sensor placed on the muscles of the lower limbs.
alt© Eurac Research | Andrea De Giovanni
The women mountaineers performed these cardiorespiratory stress tests on the cycle ergometer both at the Bolzano’s altitude and at the simulated altitude of 5,000 m.a.s.l. The test will be repeated once the K2 expedition is completed. The goal is to understand how acclimatization – the process of physiological adaptation to high altitude, affects the functioning of the respiratory, cardiovascular and muscular systems.

In June, the mountaineers will fly to Pakistan and, once acclimatization is achieved, attempt the summit in the second half of July. Having concluded their adventure, they will return to the terraXcube to repeat the tests carried out before their departure, and more. When they return, in fact, their acclimatization level will be such that they can be safely exposed to simulated altitudes above 8,000 m.a.s.l. Comparing the results of the experiments carried out before their departure with those obtained on this second occasion will shed light on how the female organism functions at extreme altitudes. An important contribution to the resolution of gender disparities in the biomedical field.

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