Nausea, vomiting, headaches: altitude sickness affects one in two people. To better understand it, 56 French people go to Mount Manaslu for 5 weeks of experiments.
Himalayan objective for Inserm! The Institute for Health and Medical Research is participating in an international experiment that will take place on the Roof of the World. Six researchers and 50 French volunteers will study the impact of high altitude on the body. Departure is scheduled for March 21.
Studying mountain sickness
The “Manaslu 2015” expedition brings together 5 teams of researchers from all over the world. For 5 weeks, the impact of altitude on the heart, brain and sleep will be studied in detail. It is Inserm unit 1042 in Grenoble (“Hypoxia and cardiovascular and respiratory pathophysiology”) which will represent France. Five groups of 10 people will leave Kathmandu on March 21 and settle in a base camp on Mount Manaslu (8,156 m). Participants, who have gone through an entire sea level assessment program, will undergo a battery of tests for 5 weeks.
“The development of leisure activities, the increase in stays at medium and high altitude for people who are sometimes inexperienced raises the question of altitude intolerance,” explains Inserm. in a press release. These adaptation difficulties result from physiopathological mechanisms associated with the decrease in oxygen availability as one rises in altitude. Mountain sickness is the most well-known symptom of this difficult adaptation. It affects one in two people above 4000 m, and three quarters of those who venture beyond 5000 m. More serious forms can occur, such as high altitude pulmonary edema or high altitude cerebral edema.
Effects on the heart and brain
The Inserm team, led by Samuel Vergès, will study in detail the adaptation of the organism to high altitude. Ultrasound, Doppler and other spectroscopies will explain this phenomenon. Indeed, studies on Mont Blanc have shown that in a situation of hypoxia, cerebral disturbances appear: the anatomy of the brain is altered, as well as its oxygenation and the function of motor neurons. The heart is also affected: the altitude alters the relaxation capacities of the myocardium and the contraction of the right ventricle.
The researchers hope to eventually develop means to limit the deleterious effects of altitude. In particular, they will assess the impact of a positive expiratory pressure (PEP) mask, which should increase intra-pulmonary pressure, and oxygenation of the blood and muscles.
Last axis, and not the least: understanding how altitude affects sleep. Because studies have shown it: hypoxia lengthens the time it takes to fall asleep, decreases the duration of deep sleep phases and promotes waking up within sleep, while promoting sleep apnea.
The expedition will last until April 26 and can be followed on social media. Inserm Facebook page offers to follow researchers live, just like the account @insermlive.
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