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Champigneulle B, Brugniaux JV, Stauffer E, Doutreleau S, Furian M, Perger E, Pina A, Baillieul S, Deschamps B, Hancco I, Connes P, Robach P, Pichon A, Verges S. Expedition 5300: limits of human adaptations in the highest city in the world. J Physiol 2023. [PMID: 38146929 DOI: 10.1113/jp284550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 12/06/2023] [Indexed: 12/27/2023] Open
Abstract
Exposure to chronic hypobaric hypoxia imposes a significant physiological burden to more than 80 million humans living above 2500 m throughout the world. Among them, 50 000 live in the world's highest city, La Rinconada, located at 5000-5300 m in southern Peru. Expedition 5300 is the first scientific and medical programme led in La Rinconada to investigate the physiological adaptations and altitude-related health issues in this unique population. Dwellers from La Rinconada have very high haemoglobin concentration (20.3 ± 2.4 g/dL; n = 57) and those with chronic mountain sickness (CMS) exhibit even higher concentrations (23.1 ± 1.7 g/dL; n = 150). These values are associated with large total haemoglobin mass and blood volume, without an associated iron deficit. These changes in intravascular volumes lead to a substantial increase in blood viscosity, which is even larger in CMS patients. Despite these large haematological changes, 24 h blood pressure monitoring is essentially normal in La Rinconada, but some results suggest impaired vascular reactivity. Echocardiography revealed large right heart dilatation and high pulmonary arterial pressure as well as left ventricle concentric remodelling and grade I diastolic dysfunction. These changes in heart dimension and function tend to be more severe in highlanders with CMS. Polygraphy evaluations revealed a large reduction in nocturnal pulse oxygen saturation (median SpO2 = 79%), which is even more severe in CMS patients who also tended to show a higher oxygen desaturation index. The population of La Rinconada offers a unique opportunity to investigate the human responses to chronic severe hypoxia, at an altitude that is probably close to the maximum altitude human beings can permanently tolerate without presenting major health issues.
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Affiliation(s)
- Benoit Champigneulle
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
| | - Julien V Brugniaux
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
| | - Emeric Stauffer
- Interuniversity Laboratory of Human Movement Biology (LIBM, EA7424), "Red Blood cell and Vascular Biology" Team, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France
| | - Stéphane Doutreleau
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
| | - Michael Furian
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
| | - Elisa Perger
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy
| | - Alessandra Pina
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy
| | - Sébastien Baillieul
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
| | - Blandine Deschamps
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
| | - Ivan Hancco
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
| | - Philippe Connes
- Interuniversity Laboratory of Human Movement Biology (LIBM, EA7424), "Red Blood cell and Vascular Biology" Team, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France
| | - Paul Robach
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
- National School for Mountain Sports, Site of the National School for Skiing and Mountaineering (ENSA), Chamonix, France
| | - Aurélien Pichon
- Laboratory Mobility, Aging & Exercise (MOVE, EA6314), Faculty of Sport Sciences, University of Poitiers, Poitiers, France
| | - Samuel Verges
- Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, HP2 laboratory, Grenoble, France
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