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Gatterer H, Villafuerte FC, Ulrich S, Bhandari SS, Keyes LE, Burtscher M. Altitude illnesses. Nat Rev Dis Primers 2024; 10:43. [PMID: 38902312 DOI: 10.1038/s41572-024-00526-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/02/2024] [Indexed: 06/22/2024]
Abstract
Millions of people visit high-altitude regions annually and more than 80 million live permanently above 2,500 m. Acute high-altitude exposure can trigger high-altitude illnesses (HAIs), including acute mountain sickness (AMS), high-altitude cerebral oedema (HACE) and high-altitude pulmonary oedema (HAPE). Chronic mountain sickness (CMS) can affect high-altitude resident populations worldwide. The prevalence of acute HAIs varies according to acclimatization status, rate of ascent and individual susceptibility. AMS, characterized by headache, nausea, dizziness and fatigue, is usually benign and self-limiting, and has been linked to hypoxia-induced cerebral blood volume increases, inflammation and related trigeminovascular system activation. Disruption of the blood-brain barrier leads to HACE, characterized by altered mental status and ataxia, and increased pulmonary capillary pressure, and related stress failure induces HAPE, characterized by dyspnoea, cough and exercise intolerance. Both conditions are progressive and life-threatening, requiring immediate medical intervention. Treatment includes supplemental oxygen and descent with appropriate pharmacological therapy. Preventive measures include slow ascent, pre-acclimatization and, in some instances, medications. CMS is characterized by excessive erythrocytosis and related clinical symptoms. In severe CMS, temporary or permanent relocation to low altitude is recommended. Future research should focus on more objective diagnostic tools to enable prompt treatment, improved identification of individual susceptibilities and effective acclimatization and prevention options.
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Affiliation(s)
- Hannes Gatterer
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy.
- Institute for Sports Medicine, Alpine Medicine and Health Tourism (ISAG), UMIT TIROL-Private University for Health Sciences and Health Technology, Hall in Tirol, Austria.
| | - Francisco C Villafuerte
- Laboratorio de Fisiología del Transporte de Oxígeno y Adaptación a la Altura - LID, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias e Ingeniería, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Sanjeeb S Bhandari
- Mountain Medicine Society of Nepal, Kathmandu, Nepal
- Emergency Department, UPMC Western Maryland Health, Cumberland, MD, USA
| | - Linda E Keyes
- Department of Emergency Medicine, University of Colorado, Aurora, CO, USA
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
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2
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Zhang X, Zhang Y, Si Y, Gao N, Zhang H, Yang H. A high altitude respiration and SpO2 dataset for assessing the human response to hypoxia. Sci Data 2024; 11:248. [PMID: 38413602 PMCID: PMC10899206 DOI: 10.1038/s41597-024-03065-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 02/13/2024] [Indexed: 02/29/2024] Open
Abstract
This report presents the Harespod dataset, an open dataset for high altitude hypoxia research, which includes respiration and SpO2 data. The dataset was collected from 15 college students aged 23-31 in a hypobaric oxygen chamber, during simulated altitude changes and induced hypoxia. Real-time physiological data, such as oxygen saturation waveforms, oxygen saturation, respiratory waveforms, heart rate, and pulse rate, were obtained at 100 Hz. Approximately 12 hours of valid data were collected from all participants. Researchers can easily identify the altitude corresponding to physiological signals based on their inherent patterns. Time markers were also recorded during altitude changes to facilitate realistic annotation of physiological signals and analysis of time-difference-of-arrival between various physiological signals for the same altitude change event. In high altitude scenarios, this dataset can be used to enhance the detection of human hypoxia states, predict respiratory waveforms, and develop related hardware devices. It will serve as a valuable and standardized resource for researchers in the field of high altitude hypoxia research, enabling comprehensive analysis and comparison.
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Affiliation(s)
- Xi Zhang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, China
- Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Yu Zhang
- School of Computer Science, Northwestern Polytechnical University, Xi'an, 710129, China.
| | - Yingjun Si
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, China
- Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Nan Gao
- Department of Computer Science and Technology, Tsinghua University, Beijing, 100084, China
| | - Honghao Zhang
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Hui Yang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.
- Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, Northwestern Polytechnical University, Xi'an, 710072, China.
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3
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Richalet JP, Hermand E, Lhuissier FJ. Cardiovascular physiology and pathophysiology at high altitude. Nat Rev Cardiol 2024; 21:75-88. [PMID: 37783743 DOI: 10.1038/s41569-023-00924-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/16/2023] [Indexed: 10/04/2023]
Abstract
Oxygen is vital for cellular metabolism; therefore, the hypoxic conditions encountered at high altitude affect all physiological functions. Acute hypoxia activates the adrenergic system and induces tachycardia, whereas hypoxic pulmonary vasoconstriction increases pulmonary artery pressure. After a few days of exposure to low oxygen concentrations, the autonomic nervous system adapts and tachycardia decreases, thereby protecting the myocardium against high energy consumption. Permanent exposure to high altitude induces erythropoiesis, which if excessive can be deleterious and lead to chronic mountain sickness, often associated with pulmonary hypertension and heart failure. Genetic factors might account for the variable prevalence of chronic mountain sickness, depending on the population and geographical region. Cardiovascular adaptations to hypoxia provide a remarkable model of the regulation of oxygen availability at the cellular and systemic levels. Rapid exposure to high altitude can have adverse effects in patients with cardiovascular diseases. However, intermittent, moderate hypoxia might be useful in the management of some cardiovascular disorders, such as coronary heart disease and heart failure. The aim of this Review is to help physicians to understand the cardiovascular responses to hypoxia and to outline some recommendations that they can give to patients with cardiovascular disease who wish to travel to high-altitude destinations.
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Affiliation(s)
- Jean-Paul Richalet
- Hypoxie et Poumon, Université Sorbonne Paris Nord, INSERM U1272, Paris, France.
| | - Eric Hermand
- Unité de Recherche Pluridisciplinaire Sport Santé Société, ULR 7369-URePSSS, Université Littoral Côte d'Opale, Université Artois, Université Lille, CHU Lille, Dunkirk, France
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4
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Zhou S, Yan J, Song K, Ge RL. High-Altitude Hypoxia Induces Excessive Erythrocytosis in Mice via Upregulation of the Intestinal HIF2a/Iron-Metabolism Pathway. Biomedicines 2023; 11:2992. [PMID: 38001992 PMCID: PMC10669251 DOI: 10.3390/biomedicines11112992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
Excessive erythrocytosis (EE) is a preclinical form of chronic mountain sickness (CMS). The dysregulation of iron metabolism in high-altitude hypoxia may induce EE. The intestinal hypoxia-inducible factor 2 alpha (HIF2a) regulates the genes involved in iron metabolism. Considering these findings, we aimed to investigate the function and mechanism of intestinal HIF2α and the iron metabolism pathway in high-altitude EE mice. C57BL/6J mice were randomized into four groups: the low-altitude group, the high-altitude group, the high-altitude + HIF2α inhibitor group, and the high-altitude + vehicle group. In-vitro experiments were performed using the human intestinal cell line HCT116 cultured under hypoxic conditions for 24 h. Results showed that high-altitude hypoxia significantly increased the expression of intestinal HIF2α and iron metabolism-related genes, including Dmt1, Dcytb, Fpn, Tfrc, and Fth in EE mice. Genetic blockade of the intestinal HIF2α-iron metabolism pathway decreased iron availability in HCT116 cells during hypoxia. The HIF2α inhibitor PT2385 suppressed intestinal HIF2α expression, decreased iron hypermetabolism, and reduced excessive erythrocytosis in mice. These data support the hypothesis that exposure to high-altitude hypoxia can lead to iron hypermetabolism by activating intestinal HIF2α transcriptional regulation, and reduced iron availability improves EE by inhibiting intestinal HIF2α signaling.
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Affiliation(s)
- Sisi Zhou
- Research Center for High Altitude Medicine, Qinghai University, Xining 810001, China; (S.Z.); (J.Y.); (K.S.)
- Key Laboratory of High-Altitude Medicine, Ministry of Education, Xining 810001, China
- Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province, Xining 810001, China
| | - Jun Yan
- Research Center for High Altitude Medicine, Qinghai University, Xining 810001, China; (S.Z.); (J.Y.); (K.S.)
- Key Laboratory of High-Altitude Medicine, Ministry of Education, Xining 810001, China
- Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province, Xining 810001, China
| | - Kang Song
- Research Center for High Altitude Medicine, Qinghai University, Xining 810001, China; (S.Z.); (J.Y.); (K.S.)
- Key Laboratory of High-Altitude Medicine, Ministry of Education, Xining 810001, China
- Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province, Xining 810001, China
| | - Ri-Li Ge
- Research Center for High Altitude Medicine, Qinghai University, Xining 810001, China; (S.Z.); (J.Y.); (K.S.)
- Key Laboratory of High-Altitude Medicine, Ministry of Education, Xining 810001, China
- Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province, Xining 810001, China
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Liu J, Ge Z, Jiang X, Zhang J, Sun J, Mao X. A comprehensive review of natural products with anti-hypoxic activity. Chin J Nat Med 2023; 21:499-515. [PMID: 37517818 DOI: 10.1016/s1875-5364(23)60410-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Indexed: 08/01/2023]
Abstract
Natural products exhibit substantial impacts in the field of anti-hypoxic traetment. Hypoxia can cause altitude sickness and other negative effect on the body. Headache, coma, exhaustion, vomiting and, in severe cases, death are some of the clinical signs. Currently, hypoxia is no longer just a concern in plateau regions; it is also one of the issues that can not be ignored by urban residents. This review covered polysaccharides, alkaloids, saponins, flavonoids, peptides and traditional Chinese compound prescriptions as natural products to protect against hypoxia. The active ingredients, effectiveness and mechanisms were discussed. The related anti-hypoxic mechanisms involve increasing the hemoglobin (HB) content, glycogen content and adenosine triphosphate (ATP) content, removing excessive reactive oxygen species (ROS), reducing lipid peroxidation, regulating the levels of related enzymes in cells, protecting the structural and functional integrity of the mitochondria and regulating the expression of apoptosis-related genes. These comprehensive summaries are beneficial to anti-hypoxic research and provide useful information for the development of anti-hypoxic products.
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Affiliation(s)
- Juncai Liu
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Zhen Ge
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Xiao Jiang
- Medical College, Qingdao Binhai University, Qingdao 266555, China
| | - Jingjing Zhang
- Medical College, Qingdao Binhai University, Qingdao 266555, China
| | - Jianan Sun
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
| | - Xiangzhao Mao
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
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Perger E, Baillieul S, Esteve F, Pichon A, Bilo G, Soranna D, Doutreleau S, Savina Y, Ulliel-Roche M, Brugniaux JV, Stauffer E, Oberholzer L, Howe C, Hannco I, Lombardi C, Tamisier R, Pepin JL, Verges S, Parati G. Nocturnal hypoxemia, blood pressure, vascular status and chronic mountain sickness in the highest city in the world. Ann Med 2022; 54:1884-1893. [PMID: 35786084 PMCID: PMC9258438 DOI: 10.1080/07853890.2022.2091791] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
INTRODUCTION Chronic mountain sickness (CMS) is a condition characterized by excessive erythrocytosis in response to chronic hypobaric hypoxia. CMS frequently triggers cardiorespiratory diseases such as pulmonary hypertension and right or left heart failure. Ambient hypoxia might be further amplified night-time by intermittent hypoxia related to sleep-disordered breathing (SDB) so that sleep disturbance may be an important feature of CMS. Our aim was to characterize in a cross-sectional study nocturnal hypoxaemia, SDB, blood pressure (BP), arterial stiffness and carotid intima-media thickness (CIMT) in highlanders living at extreme altitude. METHODS Men aged 18 to 55 years were prospectively recruited. Home sleep apnoea test, questionnaires (short-form health survey; Montreal cognitive assessment; Pittsburgh Sleep Questionnaire Index and the Insomnia severity index), 24-h ambulatory BP monitoring, CIMT and arterial stiffness were evaluated in 3 groups: i) Andean lowlanders (sea-level); ii) highlanders living at 3,800 m and iii) highlanders living at 5,100 m. Analyses were conducted in sub-groups according to 1) CMS severity 2) healthy subjects living at the three different altitude. RESULTS Ninety-two males were evaluated at their living altitudes. Among the 54 highlanders living at 5,100 m, subjects with CMS showed lower mean nocturnal oxygen saturation (SpO2), SpO2 nadir, lower pulse wave velocity and higher nocturnal BP variability than those with no-CMS. Lower nocturnal SpO2 nadir was associated with higher CMS severity (ß= -0.14, p=.009). Among the 55 healthy subjects, healthy highlanders at 5,100 m were characterized by lower scores on quality of life and sleep quality scales and lower mean SpO2 compared to lowlanders. CONCLUSIONS Lower nocturnal SpO2 and higher nocturnal BP variability are associated with CMS severity in individuals living permanently at high altitude. The role of lower SpO2 and higher nocturnal BP variability in the cardiovascular progression of CMS and in the overall prognosis of the disease need to be evaluated in further studies.
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Affiliation(s)
- Elisa Perger
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Biostatistic Unit, University of Milano-Bicocca, Milan, Italy
| | - Sébastien Baillieul
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - François Esteve
- Inserm UA7, Rayonnement Synchrotron pour la Recherche Biomédicale, Grenoble, France
| | - Aurélien Pichon
- Faculty of Sport Sciences, Université de Poitiers, Laboratory Mobility, aging & exercise (MOVE, EA6314), Poitiers, France
| | - Gzregorz Bilo
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Biostatistic Unit, University of Milano-Bicocca, Milan, Italy
| | - Davide Soranna
- Istituto Auxologico Italiano, IRCCS, Biostatistics unit, Milan, Italy
| | - Stéphane Doutreleau
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Yann Savina
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Mathilde Ulliel-Roche
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Julien V Brugniaux
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, 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
| | - Laura Oberholzer
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Connor Howe
- Centre for Heart, Lung, and Vascular Health, University of British Columbia, Kelowna, Canada
| | - Ivan Hannco
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Carolina Lombardi
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Biostatistic Unit, University of Milano-Bicocca, Milan, Italy
| | - Renaud Tamisier
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Jean-Louis Pepin
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Samuel Verges
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Gianfranco Parati
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Biostatistic Unit, University of Milano-Bicocca, Milan, Italy
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Li Z, Hu Q, Ji W, Fan Q. Prevalence of stroke and associated risk factors: a population-based cross-sectional study from the Qinghai-Tibet Plateau of China. BMJ Open 2022; 12:e065605. [PMID: 36414281 PMCID: PMC9685268 DOI: 10.1136/bmjopen-2022-065605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The epidemiology of stroke at high altitudes has not been extensively studied, especially at heights of 4000 m and above. Thus, stroke prevention and treatment at high altitudes are challenging. We conducted a cross-sectional study to estimate the prevalence of stroke, the detection rate of individuals at high risk of stroke and the risk factors for stroke in the Qinghai-Tibet Plateau in China, a high altitude plateau that inhabits approximately 15 million people. DESIGN A population-based cross-sectional study in the Qinghai-Tibet Plateau. SETTING Data were collected from participants through face-to-face screening using a primary screening table. The table relied on the China National Stroke Screening and Prevention Project. PARTICIPANTS A total of 10 700 residents aged ≥40 years and living on the Qinghai-Tibet Plateau for more than 6 months participated from January 2019 to December 2021. MAIN OUTCOME MEASURES The primary screening table included basic demographic information, medical history information, personal lifestyle habits and physical examination information. RESULTS A total of 10 056 people were included in the analysis. The prevalence of stroke was 2.3% (95% CI 2.0% to 2.6%), and the detection rate of individuals at high risk of stroke was 26.2% (95% CI 25.3% to 27.0%). The prevalence of stroke and the detection rate of individuals at high risk of stroke increased with altitude (p<0.01), and the prevalence of stroke at high altitudes was almost 2.2 times that at mid-altitudes (p<0.01). After full adjustments, age, residence, hypertension, family history of stroke and smoking were significantly associated with stroke (p<0.05). CONCLUSIONS The prevalence of stroke, the related risk factors and the detection rate of high-risk individuals were clarified. The prevalence rates of hypertension, overweight or obesity and diabetes in the Qinghai-Tibet Plateau were all higher than the Chinese average. Higher-altitude exposure may be an independent risk factor for stroke.
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Affiliation(s)
| | - QuanZhong Hu
- Qinghai Provincial People's Hospital, Xining, China
| | - WeiZhong Ji
- Qinghai Provincial People's Hospital, Xining, China
| | - QingLi Fan
- Qinghai Provincial People's Hospital, Xining, China
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Yu JJ, Non AL, Heinrich EC, Gu W, Alcock J, Moya EA, Lawrence ES, Tift MS, O'Brien KA, Storz JF, Signore AV, Khudyakov JI, Milsom WK, Wilson SM, Beall CM, Villafuerte FC, Stobdan T, Julian CG, Moore LG, Fuster MM, Stokes JA, Milner R, West JB, Zhang J, Shyy JY, Childebayeva A, Vázquez-Medina JP, Pham LV, Mesarwi OA, Hall JE, Cheviron ZA, Sieker J, Blood AB, Yuan JX, Scott GR, Rana BK, Ponganis PJ, Malhotra A, Powell FL, Simonson TS. Time Domains of Hypoxia Responses and -Omics Insights. Front Physiol 2022; 13:885295. [PMID: 36035495 PMCID: PMC9400701 DOI: 10.3389/fphys.2022.885295] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023] Open
Abstract
The ability to respond rapidly to changes in oxygen tension is critical for many forms of life. Challenges to oxygen homeostasis, specifically in the contexts of evolutionary biology and biomedicine, provide important insights into mechanisms of hypoxia adaptation and tolerance. Here we synthesize findings across varying time domains of hypoxia in terms of oxygen delivery, ranging from early animal to modern human evolution and examine the potential impacts of environmental and clinical challenges through emerging multi-omics approaches. We discuss how diverse animal species have adapted to hypoxic environments, how humans vary in their responses to hypoxia (i.e., in the context of high-altitude exposure, cardiopulmonary disease, and sleep apnea), and how findings from each of these fields inform the other and lead to promising new directions in basic and clinical hypoxia research.
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Affiliation(s)
- James J. Yu
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Amy L. Non
- Department of Anthropology, Division of Social Sciences, University of California, San Diego, La Jolla, CA, United States,*Correspondence: Amy L. Non, Tatum S. Simonson,
| | - Erica C. Heinrich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, United States
| | - Wanjun Gu
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,Herbert Wertheim School of Public Health and Longevity Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Joe Alcock
- Department of Emergency Medicine, University of New Mexico, Albuquerque, MX, United States
| | - Esteban A. Moya
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Elijah S. Lawrence
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Michael S. Tift
- Department of Biology and Marine Biology, College of Arts and Sciences, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Katie A. O'Brien
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,Department of Physiology, Development and Neuroscience, Faculty of Biology, School of Biological Sciences, University of Cambridge, Cambridge, ENG, United Kingdom
| | - Jay F. Storz
- School of Biological Sciences, College of Arts and Sciences, University of Nebraska-Lincoln, Lincoln, IL, United States
| | - Anthony V. Signore
- School of Biological Sciences, College of Arts and Sciences, University of Nebraska-Lincoln, Lincoln, IL, United States
| | - Jane I. Khudyakov
- Department of Biological Sciences, University of the Pacific, Stockton, CA, United States
| | | | - Sean M. Wilson
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda, CA, United States
| | | | | | | | - Colleen G. Julian
- School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Lorna G. Moore
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, Aurora, CO, United States
| | - Mark M. Fuster
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Jennifer A. Stokes
- Department of Kinesiology, Southwestern University, Georgetown, TX, United States
| | - Richard Milner
- San Diego Biomedical Research Institute, San Diego, CA, United States
| | - John B. West
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Jiao Zhang
- Department of Medicine, UC San Diego School of Medicine, San Diego, CA, United States
| | - John Y. Shyy
- Department of Medicine, UC San Diego School of Medicine, San Diego, CA, United States
| | - Ainash Childebayeva
- Department of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - José Pablo Vázquez-Medina
- Department of Integrative Biology, College of Letters and Science, University of California, Berkeley, Berkeley, CA, United States
| | - Luu V. Pham
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, Johns Hopkins Medicine, Baltimore, MD, United States
| | - Omar A. Mesarwi
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - James E. Hall
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Zachary A. Cheviron
- Division of Biological Sciences, College of Humanities and Sciences, University of Montana, Missoula, MT, United States
| | - Jeremy Sieker
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Arlin B. Blood
- Department of Pediatrics Division of Neonatology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Jason X. Yuan
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Graham R. Scott
- Department of Pediatrics Division of Neonatology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Brinda K. Rana
- Moores Cancer Center, UC San Diego, La Jolla, CA, United States,Department of Psychiatry, UC San Diego, La Jolla, CA, United States
| | - Paul J. Ponganis
- Center for Marine Biotechnology and Biomedicine, La Jolla, CA, United States
| | - Atul Malhotra
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Frank L. Powell
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Tatum S. Simonson
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,*Correspondence: Amy L. Non, Tatum S. Simonson,
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9
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Villafuerte FC, Simonson TS, Bermudez D, León-Velarde F. High-Altitude Erythrocytosis: Mechanisms of Adaptive and Maladaptive Responses. Physiology (Bethesda) 2022; 37:0. [PMID: 35001654 PMCID: PMC9191173 DOI: 10.1152/physiol.00029.2021] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Erythrocytosis, or increased production of red blood cells, is one of the most well-documented physiological traits that varies within and among in high-altitude populations. Although a modest increase in blood O2-carrying capacity may be beneficial for life in highland environments, erythrocytosis can also become excessive and lead to maladaptive syndromes such as chronic mountain sickness (CMS).
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Affiliation(s)
- Francisco C. Villafuerte
- 1Laboratorio de Fisiología Comparada/Laboratorio de Fisiología del Transporte de Oxígeno, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Tatum S. Simonson
- 2Division of Pulmonary, Critical Care, and Sleep Medicine, School of Medicine, University of California, San Diego, La Jolla, California
| | - Daniela Bermudez
- 1Laboratorio de Fisiología Comparada/Laboratorio de Fisiología del Transporte de Oxígeno, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Fabiola León-Velarde
- 1Laboratorio de Fisiología Comparada/Laboratorio de Fisiología del Transporte de Oxígeno, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
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10
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Schmidt WFJ, Wachsmuth N, Jimenez J, Soria R. Hemoglobin Mass and Blood Volume in Patients With Altitude-Related Polycythemia. Front Physiol 2022; 13:867108. [PMID: 35574463 PMCID: PMC9096560 DOI: 10.3389/fphys.2022.867108] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
Patients with chronic mountain sickness (CMS) have a high hemoglobin concentration [Hb] due to increased hemoglobin mass (Hbmass) and possibly reduced plasma volume (PV). The values of Hbmass, PV and blood volume (BV) have been described differently, and the relationships between [Hb] and Hbmass or PV are poorly understood. This study obtained representative Hbmass, PV and BV data from healthy, high-altitude residents and CMS patients and quantified the dependency of [Hb] on Hbmass and PV. METHODS Eighty-seven subjects born at high altitude (∼3,900 m) were enrolled. Thirty-four had CMS (CMS), 11 had polycythemia without CMS (intermediate, IM), 20 were healthy highlanders (HH), and 22 living near sea level (SL, 420 m) served as the sea level (SL) control group. Hbmass, PV and BV were determined using a CO-rebreathing method modified for assessing polycythemia patients. Furthermore, [Hb], hematocrit (Hct), plasma erythropoietin concentration [EPO] and blood gas and acid-base status were determined. RESULTS In the HH group, Hbmass was 27% higher (940 ± 105 g) than in the SL group (740 ± 112 g) and 72% (1,617 ± 265 g) lower than in the CMS group. The PV in the HH group was similar to that in the SL group (-6%) and 15% higher than that in the CMS group (p < 0.001). In the HH group, the BV (5,936 ± 673 ml) did not differ from that in the SL group and was 28% lower than in the CMS group (7,606 ± 1075 ml, p < 0.001). Log [EPO] was slightly increased in the CMS group relative to the HH group (p < 0.01). All values in the IM group were between those in the HH and CMS groups. Hbmass and BV were positively correlated, and PV was negatively correlated with peripheral O2 saturation. Increased Hbmass and decreased PV contributed approximately 65 and 35%, respectively, to the difference in [Hb] between the HH (17.1 ± 0.8 g/dl) and CMS (22.1 ± 1.0 g/dl) groups. CONCLUSIONS In CMS patients, the decrease in PV only partially compensated for the substantial increase in Hbmass, but it did not prevent an increase in BV; the decrease in PV contributed to an excessively high [Hb].
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Affiliation(s)
- Walter F J Schmidt
- Department of Sports Medicine and Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - Nadine Wachsmuth
- Department of Sports Medicine and Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - Jesus Jimenez
- Instituto Boliviano de Biologia de Altura, Universidad Mayor de San Andres, La Paz, Bolivia
| | - Rudy Soria
- Instituto Boliviano de Biologia de Altura, Universidad Mayor de San Andres, La Paz, Bolivia
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11
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Hansen AB, Amin SB, Hofstätter F, Mugele H, Simpson LL, Gasho C, Dawkins TG, Tymko MM, Ainslie PN, Villafuerte FC, Hearon CM, Lawley JS, Moralez G. Global Reach 2018: sympathetic neural and hemodynamic responses to submaximal exercise in Andeans with and without chronic mountain sickness. Am J Physiol Heart Circ Physiol 2022; 322:H844-H856. [PMID: 35333117 PMCID: PMC9018046 DOI: 10.1152/ajpheart.00555.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 03/14/2022] [Accepted: 03/14/2022] [Indexed: 11/22/2022]
Abstract
Andeans with chronic mountain sickness (CMS) and polycythemia have similar maximal oxygen uptakes to healthy Andeans. Therefore, this study aimed to explore potential adaptations in convective oxygen transport, with a specific focus on sympathetically mediated vasoconstriction of nonactive skeletal muscle. In Andeans with (CMS+, n = 7) and without (CMS-, n = 9) CMS, we measured components of convective oxygen delivery, hemodynamic (arterial blood pressure via intra-arterial catheter), and autonomic responses [muscle sympathetic nerve activity (MSNA)] at rest and during steady-state submaximal cycling exercise [30% and 60% peak power output (PPO) for 5 min each]. Cycling caused similar increases in heart rate, cardiac output, and oxygen delivery at both workloads between both Andean groups. However, at 60% PPO, CMS+ had a blunted reduction in Δtotal peripheral resistance (CMS-, -10.7 ± 3.8 vs. CMS+, -4.9 ± 4.1 mmHg·L-1·min-1; P = 0.012; d = 1.5) that coincided with a greater Δforearm vasoconstriction (CMS-, -0.2 ± 0.6 vs. CMS+, 1.5 ± 1.3 mmHg·mL-1·min-1; P = 0.008; d = 1.7) and a rise in Δdiastolic blood pressure (CMS-, 14.2 ± 7.2 vs. CMS+, 21.6 ± 4.2 mmHg; P = 0.023; d = 1.2) compared with CMS-. Interestingly, although MSNA burst frequency did not change at 30% or 60% of PPO in either group, at 60% Δburst incidence was attenuated in CMS+ (P = 0.028; d = 1.4). These findings indicate that in Andeans with polycythemia, light intensity exercise elicited similar cardiovascular and autonomic responses compared with CMS-. Furthermore, convective oxygen delivery is maintained during moderate-intensity exercise despite higher peripheral resistance. In addition, the elevated peripheral resistance during exercise was not mediated by greater sympathetic neural outflow, thus other neural and/or nonneural factors are perhaps involved.NEW & NOTEWORTHY During submaximal exercise, convective oxygen transport is maintained in Andeans suffering from polycythemia. Light intensity exercise elicited similar cardiovascular and autonomic responses compared with healthy Andeans. However, during moderate-intensity exercise, we observed a blunted reduction in total peripheral resistance, which cannot be ascribed to an exaggerated increase in muscle sympathetic nerve activity, indicating possible contributions from other neural and/or nonneural mechanisms.
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Affiliation(s)
- Alexander B Hansen
- Division of Performance, Physiology and Prevention, Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Sachin B Amin
- Division of Performance, Physiology and Prevention, Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Florian Hofstätter
- Division of Performance, Physiology and Prevention, Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Hendrik Mugele
- Division of Performance, Physiology and Prevention, Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Lydia L Simpson
- Division of Performance, Physiology and Prevention, Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Christopher Gasho
- Division of Pulmonary and Critical Care, Department of Medicine, University of Loma Linda, Loma Linda, California
| | - Tony G Dawkins
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom
| | - Michael M Tymko
- Physical Activity and Diabetes Laboratory, Faculty of Kinesiology and Recreation, University of Alberta, Edmonton, Alberta, Canada
- Centre of Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Philip N Ainslie
- Centre of Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Francisco C Villafuerte
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígeno Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Christopher M Hearon
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, Texas
| | - Justin S Lawley
- Division of Performance, Physiology and Prevention, Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Gilbert Moralez
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
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12
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Ortiz-Prado E, Cordovez SP, Vasconez E, Viscor G, Roderick P. Chronic high-altitude exposure and the epidemiology of ischaemic stroke: a systematic review. BMJ Open 2022; 12:e051777. [PMID: 35487749 PMCID: PMC9058702 DOI: 10.1136/bmjopen-2021-051777] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION About 5.7% of the world population resides above 1500 m. It has been hypothesised that acute exposure to high-altitude locations can increase stroke risk, while chronic hypoxia can reduce stroke-related mortality. OBJECTIVE This review aims to provide an overview of the available evidence on the association between long-term high-altitude exposure and ischaemic stroke. DESIGN A systematic review was performed from 1 January 1960 to 1 December 2021 to assess the possible link between high-altitude exposure and ischaemic stroke. The AMED, EMBASE, Cochrane Library, PubMed, MEDLINE, the Europe PubMed Central and the Latin-American bibliographic database Scielo were accessed using the University of Southampton library tool Delphis. In this review, we included population and individual-based observational studies, including cross-sectional and longitudinal studies except for those merely descriptive individual-based case reports. Studies were limited to humans living or visiting high-altitude locations for at least 28 days as a cut-off point for chronic exposure. RESULTS We reviewed a total of 1890 abstracts retrieved during the first step of the literature review process. The authors acquired in full text as potentially relevant 204 studies. Only 17 documents met the inclusion criteria and were finally included. Ten studies clearly suggest that living at high altitudes may be associated with an increased risk of stroke; however, five studies suggest that altitude may act as a protective factor for the development of stroke, while two studies report ambiguous results. CONCLUSIONS This review suggests that the most robust studies are more likely to find that prolonged living at higher altitudes reduces the risk of developing stroke or dying from it. Increased irrigation due to angiogenesis and increased vascular perfusion might be the reason behind improved survival profiles among those living within this altitude range. In contrast, residing above 3500 m seems to be associated with an apparent increased risk of developing stroke, probably linked to the presence of polycythaemia and other associated factors such as increased blood viscosity.
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Affiliation(s)
- Esteban Ortiz-Prado
- One Health Research Group, Universidad de Las Américas, Quito, Ecuador
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
| | - Simone Pierina Cordovez
- One Health Research Group, Universidad de Las Américas, Quito, Ecuador
- Facultad de Medicina, Universidad San Gregorio de Portoviejo, Portoviejo, Manabi, Ecuador
| | - Eduardo Vasconez
- One Health Research Group, Universidad de Las Américas, Quito, Ecuador
| | - Ginés Viscor
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
| | - Paul Roderick
- Faculty of Medicine, University of Southampton, Southampton, UK
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13
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Venkat D, Dhillon K, Rowley JA. Effects of High Altitude on Sleep and Respiratory System. CURRENT PULMONOLOGY REPORTS 2021. [DOI: 10.1007/s13665-021-00276-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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14
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Richalet JP. [Adaption to chronic hypoxaemia by populations living at high altitude]. Rev Mal Respir 2021; 38:395-403. [PMID: 33541755 DOI: 10.1016/j.rmr.2020.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 10/13/2020] [Indexed: 12/14/2022]
Abstract
Permanent life at high altitude induces important physiological stresses linked to the exposure to chronic hypoxia. Various strategies have been adopted by diverse populations living in the Andes, Tibet or East Africa. The main mechanism is an increase in red blood cell production, more marked in Andeans than in Tibetans or Ethiopians. Other changes are observed in the cardiovascular or respiratory systems, as well as in the utero-placental circulation. Sometimes, a de-adaptation process to hypoxia develops, when erythrocytosis becomes excessive and leads to haematological, vascular and cerebral complications (Monge's disease or chronic mountain sickness). Pulmonary hypertension may also appear. Therapeutic options are available but not sufficiently used. Genetic studies have recently been undertaken to try to better understand the evolution of the human genome in populations living in various high altitude regions of the world, as well as the genetic risk factors for chronic diseases. A new model has appeared, intermittent chronic hypoxia, due to the development of economic activities (mainly mining) in desert regions of the Altiplano.
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Affiliation(s)
- J-P Richalet
- Laboratoire « Hypoxie & Poumon », UMR Inserm U1272, Université Sorbonne Paris Nord 13, 74, rue Marcel-Cachin, 93017 Bobigny cedex, France.
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15
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Shao X, Dong X, Cai J, Tang C, Xie K, Yan Z, Luo E, Jing D. Oxygen Enrichment Ameliorates Cardiorespiratory Alterations Induced by Chronic High-Altitude Hypoxia in Rats. Front Physiol 2021; 11:616145. [PMID: 33488404 PMCID: PMC7817980 DOI: 10.3389/fphys.2020.616145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 12/07/2020] [Indexed: 12/23/2022] Open
Abstract
Chronic high-altitude hypoxia (HAH) results in compensatory pathological adaptations, especially in the cardiorespiratory system. The oxygen enrichment technology can provide long-lasting oxygen supply and minimize oxygen toxicity, which has proven to be effective to increase oxygen saturation, decrease heart rate, and improve human exercise performance after ascending to high altitudes. Nevertheless, it remains unknown whether oxygen enrichment can resist chronic HAH-induced cardiorespiratory alterations. Thirty-six male rats were equally assigned to the normal control (NC), HAH, and HAH with oxygen enrichment (HAHO) groups. The HAH and HAHO rats were housed in a hypobaric hypoxia chamber equivalent to 5,000 m for 4 weeks. The HAHO rats were exposed to oxygen-enriched air for 8 h/day. We found that oxygen enrichment mitigated the augmented skin blood flow and improved the locomotor activity of HAH-exposed rats. Oxygen enrichment inhibited HAH-induced increase in the production of red blood cells (RBCs). The hemodynamic results showed that oxygen enrichment decreased right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) in HAH-exposed rats. HAH-associated right ventricular hypertrophy and cardiomyocyte enlargement were ameliorated by oxygen enrichment. Oxygen enrichment inhibited HAH-induced excessive expression of cytokines associated with cardiac hypertrophy and myocardial fibrosis [angiotensin-converting enzyme (ACE)/angiotensin-converting enzyme 2 (ACE2), angiotensin II (Ang II), collagen type I alpha 1 (Col1α1), collagen type III alpha 1 (Col3α1), and hydroxyproline] in the right ventricle (RV). Oxygen enrichment inhibited medial thickening, stenosis and fibrosis of pulmonary arterioles, and cytokine expression related with fibrosis (Col1α1, Col3α1, and hydroxyproline) and pulmonary vasoconstriction [endothelin-1(ET-1)] in HAH-exposed rats. This study represents the first effort testing the efficacy of the oxygen enrichment technique on cardiopulmonary structure and function in chronic HAH animals, and we found oxygen enrichment has the capability of ameliorating chronic HAH-induced cardiopulmonary alterations.
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Affiliation(s)
- Xi Shao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Xu Dong
- Recuperation Management Office, Department of Medical Management and Training, Qingdao Special Service Recuperation Center of PLA Navy, Qingdao, China
| | - Jing Cai
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,College of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Chi Tang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Kangning Xie
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Zedong Yan
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Da Jing
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
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16
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Novel insights into plasma biomarker candidates in patients with chronic mountain sickness based on proteomics. Biosci Rep 2021; 41:227462. [PMID: 33393624 PMCID: PMC7816071 DOI: 10.1042/bsr20202219] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 12/16/2022] Open
Abstract
Chronic mountain sickness (CMS) is a progressive incapacitating syndrome induced by lifelong exposure to hypoxia. In the present study, proteomic analysis was used to identify the differentially expressed proteins (DEPs) and then evaluate the potential plasma biomarkers between CMS and non-CMS groups. A total of 145 DEPs were detected in CMS Han Chinese people who live in the plateau (CMS-HPu), among which 89 were significantly up-regulated and 56 were significantly down-regulated. GO enrichment analysis showed that various biological processes were enriched, including the hydrogen peroxide metabolic/catabolic process, reactive oxygen species (ROS) metabolic, and acute inflammatory response. Protein–protein interaction analysis showed that antioxidant activity, the hydrogen peroxide catabolic process and peroxidase activity were primarily mapped in interaction proteins. Nine modules showed significantly clustering based on WGCNA analysis, with two being the most significant, and GO analysis showed that proteins of both modules were primarily enriched in oxidative stress-related biological processes. Four DEPs increased in CMS patients were evaluated as the candidate biomarkers, and three showed significant AUC: hemoglobin β chain (HB-β), thioredoxin-1 (TRX1), and phosphoglycerate kinase 1 (PGK1). The present study provides insights into the pathogenesis of CMS and further evaluates the potentially biomarkers for its prevention and treatment of it.
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17
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Stauffer E, Loyrion E, Hancco I, Waltz X, Ulliel‐Roche M, Oberholzer L, Robach P, Pichon A, Brugniaux JV, Bouzat P, Doutreleau S, Connes P, Verges S. Blood viscosity and its determinants in the highest city in the world. J Physiol 2020; 598:4121-4130. [DOI: 10.1113/jp279694] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 05/07/2020] [Indexed: 12/14/2022] Open
Affiliation(s)
- Emeric Stauffer
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424 Team ‘Biologie vasculaire et du globule rouge’ Université Claude Bernard Lyon 1 Université de Lyon France
- Laboratoire d'Excellence du Globule Rouge (Labex GR‐Ex) PRES Sorbonne Paris France
- Centre de Médecine du Sommeil et des Maladies Respiratoires Hospices Civils de Lyon Hôpital Croix Rousse Lyon France
| | - Emmanuelle Loyrion
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Ivan Hancco
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Xavier Waltz
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Mathilde Ulliel‐Roche
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Laura Oberholzer
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research Rigshospitalet University of Copenhagen Copenhagen Denmark
| | - Paul Robach
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
- National School for Mountain Sports Site of the National School for Skiing and Mountaineering (ENSA) Chamonix France
| | | | - Julien V. Brugniaux
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Pierre Bouzat
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Stéphane Doutreleau
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Philippe Connes
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424 Team ‘Biologie vasculaire et du globule rouge’ Université Claude Bernard Lyon 1 Université de Lyon France
- Laboratoire d'Excellence du Globule Rouge (Labex GR‐Ex) PRES Sorbonne Paris France
- Institut Universitaire de France Paris France
| | - Samuel Verges
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
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18
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Simpson LL, Meah VL, Steele AR, Gasho C, Howe CA, Dawkins TG, Busch SA, Oliver SJ, Moralez G, Lawley JS, Tymko MM, Vizcardo-Galindo GA, Figueroa-Mujíca RJ, Villafuerte FC, Ainslie PN, Stembridge M, Steinback CD, Moore JP. Global REACH 2018: Andean highlanders, chronic mountain sickness and the integrative regulation of resting blood pressure. Exp Physiol 2020; 106:104-116. [PMID: 32271969 DOI: 10.1113/ep088473] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/06/2020] [Indexed: 12/17/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does chronic mountain sickness (CMS) alter sympathetic neural control and arterial baroreflex regulation of blood pressure in Andean (Quechua) highlanders? What is the main finding and its importance? Compared to healthy Andean highlanders, basal sympathetic vasomotor outflow is lower, baroreflex control of muscle sympathetic nerve activity is similar, supine heart rate is lower and cardiovagal baroreflex gain is greater in mild CMS. Taken together, these findings reflect flexibility in integrative regulation of blood pressure that may be important when blood viscosity and blood volume are elevated in CMS. ABSTRACT The high-altitude maladaptation syndrome chronic mountain sickness (CMS) is characterized by excessive erythrocytosis and frequently accompanied by accentuated arterial hypoxaemia. Whether altered autonomic cardiovascular regulation is apparent in CMS is unclear. Therefore, during the 2018 Global REACH expedition to Cerro de Pasco, Peru (4383 m), we assessed integrative control of blood pressure (BP) and determined basal sympathetic vasomotor outflow and arterial baroreflex function in eight Andean natives with CMS ([Hb] 22.6 ± 0.9 g·dL-1 ) and seven healthy highlanders ([Hb] 19.3 ± 0.8 g·dL-1 ). R-R interval (RRI, electrocardiogram), beat-by-beat BP (photoplethysmography) and muscle sympathetic nerve activity (MSNA; microneurography) were recorded at rest and during pharmacologically induced changes in BP (modified Oxford test). Although [Hb] and blood viscosity (7.8 ± 0.7 vs. 6.6 ± 0.7 cP; d = 1.7, P = 0.01) were elevated in CMS compared to healthy highlanders, cardiac output, total peripheral resistance and mean BP were similar between groups. The vascular sympathetic baroreflex MSNA set-point (i.e. MSNA burst incidence) and reflex gain (i.e. responsiveness) were also similar between groups (MSNA set-point, d = 0.75, P = 0.16; gain, d = 0.2, P = 0.69). In contrast, in CMS the cardiovagal baroreflex operated around a longer RRI (960 ± 159 vs. 817 ± 50 ms; d = 1.4, P = 0.04) with a greater reflex gain (17.2 ± 6.8 vs. 8.8 ± 2.6 ms·mmHg-1 ; d = 1.8, P = 0.01) versus healthy highlanders. Basal sympathetic vasomotor activity was also lower compared to healthy highlanders (33 ± 11 vs. 45 ± 13 bursts·min-1 ; d = 1.0, P = 0.08). In conclusion, our findings indicate adaptive differences in basal sympathetic vasomotor activity and heart rate compensate for the haemodynamic consequences of excessive erythrocyte volume and contribute to integrative blood pressure regulation in Andean highlanders with mild CMS.
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Affiliation(s)
- Lydia L Simpson
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK
| | - Victoria L Meah
- Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Canada
| | - Andrew R Steele
- Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Canada
| | - Christopher Gasho
- Division of Pulmonary and Critical Care, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Connor A Howe
- Centre for Heart, Lung, and Vascular Health, University of British Columbia Okanagan, Kelowna, Canada
| | - Tony G Dawkins
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Stephen A Busch
- Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Canada
| | - Samuel J Oliver
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK
| | - Gilberto Moralez
- Department of Applied Clinical Research, University of Texas Southwestern Medical Centre, Dallas, TX, USA
| | - Justin S Lawley
- Department of Sport Science, Division of Physiology, University of Innsbruck, Innsbruck, Austria
| | - Michael M Tymko
- Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Canada
| | | | - Rómulo J Figueroa-Mujíca
- Department of Biological and Physiological Sciences, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Francisco C Villafuerte
- Department of Biological and Physiological Sciences, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Phillip N Ainslie
- Centre for Heart, Lung, and Vascular Health, University of British Columbia Okanagan, Kelowna, Canada
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Craig D Steinback
- Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Canada
| | - Jonathan P Moore
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK
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19
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Gupta A, Gupta R, Kumar V, Samarany S. Blue Toes at High Altitude: Peripheral Cyanosis. Am J Med 2020; 133:573-575. [PMID: 31668899 DOI: 10.1016/j.amjmed.2019.08.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 08/20/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Amol Gupta
- Heart, Vascular, and Leg Center, Bakersfield, Calif
| | - Ravi Gupta
- Heart, Vascular, and Leg Center, Bakersfield, Calif
| | - Vinod Kumar
- Heart, Vascular, and Leg Center, Bakersfield, Calif.
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Bermudez D, Azad P, Figueroa-Mujíca R, Vizcardo-Galindo G, Corante N, Guerra-Giraldez C, Haddad GG, Villafuerte FC. Increased hypoxic proliferative response and gene expression in erythroid progenitor cells of Andean highlanders with chronic mountain sickness. Am J Physiol Regul Integr Comp Physiol 2020; 318:R49-R56. [PMID: 31617751 PMCID: PMC6985794 DOI: 10.1152/ajpregu.00250.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 12/20/2022]
Abstract
Excessive erythrocytosis (EE) is the main sign of chronic mountain sickness (CMS), a maladaptive clinical syndrome prevalent in Andean and other high-altitude populations worldwide. The pathophysiological mechanism of EE is still controversial, as physiological variability of systemic respiratory, cardiovascular, and hormonal responses to chronic hypoxemia complicates the identification of underlying causes. Induced pluripotent stem cells derived from CMS highlanders showed increased expression of genes relevant to the regulation of erythropoiesis, angiogenesis, cardiovascular, and steroid-hormone function that appear to explain the exaggerated erythropoietic response. However, the cellular response to hypoxia in native CMS cells is yet unknown. This study had three related aims: to determine the hypoxic proliferation of native erythroid progenitor burst-forming unit-erythroid (BFU-E) cells derived from CMS and non-CMS peripheral blood mononuclear cells; to examine their sentrin-specific protease 1 (SENP1), GATA-binding factor 1 (GATA1), erythropoietin (EPO), and EPO receptor (EPOR) expression; and to investigate the functional upstream role of SENP1 in native progenitor differentiation into erythroid precursors. Native CMS BFU-E colonies showed increased proliferation under hypoxic conditions compared with non-CMS cells, together with an upregulated expression of SENP1, GATA1, EPOR; and no difference in EPO expression. Knock-down of the SENP1 gene abolished the augmented proliferative response. Thus, we demonstrate that native CMS progenitor cells produce a larger proportion of erythroid precursors under hypoxia and that SENP1 is essential for proliferation. Our findings suggest a significant intrinsic component for developing EE in CMS highlanders at the cellular and gene expression level that could be further enhanced by systemic factors such as alterations in respiratory control, or differential hormonal patterns.
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Affiliation(s)
- Daniela Bermudez
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Priti Azad
- Division of Respiratory Medicine, Department of Pediatrics, University of California, San Diego, La Jolla, California
| | - Rómulo Figueroa-Mujíca
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Gustavo Vizcardo-Galindo
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Noemí Corante
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Cristina Guerra-Giraldez
- Laboratorio de Inflamación Cerebral, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Gabriel G Haddad
- Division of Respiratory Medicine, Department of Pediatrics, University of California, San Diego, La Jolla, California
- Department of Neurosciences, University of California San Diego, La Jolla, California
- Rady Children's Hospital, San Diego, La Jolla, California
| | - Francisco C Villafuerte
- Laboratorio de Fisiología Comparada, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Instituto de Investigaciones de la Altura (IIA), Universidad Peruana Cayetano Heredia, Lima, Peru
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Wachsmuth N, Soria R, Jimenez J, Schmidt W. Modification of the CO‐rebreathing method to determine haemoglobin mass and blood volume in patients suffering from chronic mountain sickness. Exp Physiol 2019; 104:1819-1828. [DOI: 10.1113/ep087870] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/26/2019] [Indexed: 01/19/2023]
Affiliation(s)
- Nadine Wachsmuth
- Department of Sports Medicine & Sports PhysiologyUniversity of Bayreuth Bayreuth Germany
| | - Rudy Soria
- Instituto Boliviano de Biologia de AlturaUniversidad Mayor de San Andres La Paz Bolivia
| | - Jesus Jimenez
- Instituto Boliviano de Biologia de AlturaUniversidad Mayor de San Andres La Paz Bolivia
| | - Walter Schmidt
- Department of Sports Medicine & Sports PhysiologyUniversity of Bayreuth Bayreuth Germany
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Naeije R. Pulmonary hypertension at high altitude. Eur Respir J 2019; 53:53/6/1900985. [DOI: 10.1183/13993003.00985-2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 05/16/2019] [Indexed: 11/05/2022]
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Daily Chronic Intermittent Hypobaric Hypoxia Does Not Induce Chronic Increase in Pulmonary Arterial Pressure Assessed by Echocardiography. Can Respir J 2018; 2018:9649716. [PMID: 29808103 PMCID: PMC5902055 DOI: 10.1155/2018/9649716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/25/2018] [Indexed: 11/17/2022] Open
Abstract
Chronic hypoxia causes pulmonary vascular remodeling resulting in persistently increased pulmonary arterial pressures (PAP) even after return to normoxia. Recently, interest in chronic intermittent hypobaric hypoxia (CIHH) was raised because it occurs in subjects working at high altitude (HA) but living in lowland. However, effects of daily CIHH on PAP are unknown. In this pilot study, we included 8 healthy subjects working at (2650 m) each workday for 8-9 h while living and sleeping at LA and 8 matched control subjects living and working at LA. Cardiorespiratory measurements including echocardiography at rest and during exercise were performed at LA (Munich, 530 m) and HA (Zugspitze, 2650 m). Hemoglobin was higher in CIHH subjects. LA echocardiography showed normal right and left cardiac dimensions and function in all subjects. Systolic PAP (sPAP) and tricuspid annular plane systolic excursion (TAPSE) at rest were similar in both groups. Resting blood gas analysis (BGA) at HA revealed decreased pCO2 in CIHH compared to controls (HA: 28.4 versus 31.7 mmHg, p=0.01). During exercise, sPAP was lower in CIHH subjects compared to controls (LA: 28.7 versus 35.3 mmHg, p=0.02; HA: 26.3 versus 33.6 mmHg, p=0.04) and peripheral oxygen saturation (SpO2) was higher. In sum, subjects exposed to CIHH showed no signs of pulmonary vascular remodeling.
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Laouafa S, Elliot-Portal E, Revollo S, Schneider Gasser EM, Joseph V, Voituron N, Gassmann M, Soliz J. Hypercapnic ventilatory response is decreased in a mouse model of excessive erythrocytosis. Am J Physiol Regul Integr Comp Physiol 2016; 311:R940-R947. [PMID: 27605561 DOI: 10.1152/ajpregu.00226.2016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/10/2016] [Indexed: 11/22/2022]
Abstract
The impact of cerebral erythropoietin (Epo) in the regulation of the hypercapnic ventilatory response (HcVR) is controversial. While we reported that cerebral Epo does not affect the central chemosensitivity in C57Bl6 mice receiving an intracisternal injection of sEpoR (the endogenous antagonist of Epo), a recent study in transgenic mice with constitutive high levels of human Epo in brain and circulation (Tg6) and in brain only (Tg21), showed that Epo blunts the HcVR, maybe by interacting with central and peripheral chemoreceptors. High Epo serum levels in Tg6 mice lead to excessive erythrocytosis (hematocrit ~80-90%), the main symptom of chronic mountain sickness (CMS). These latter results support the hypothesis that reduced central chemosensitivity accounts for the hypoventilation observed in CMS patients. To solve this intriguing divergence, we reevaluate HcVR in Tg6 and Tg21 mouse lines, by assessing the metabolic rate [O consumption (V̇) and CO production (V̇)], a key factor modulating ventilation, the effect of which was not considered in the previous study. Our results showed that the decreased HcVR observed in Tg6 mice (~70% reduction; < 0.01) was due to a significant decrease in the metabolism (~40%; < 0.0001) rather than Epo's effect on CO chemosensitivity. Additional analysis in Tg21 mice did not reveal differences of HcVR or metabolism. We concluded that cerebral Epo does not modulate the central chemosensitivity system, and that a metabolic effect upon CO inhalation is responsible for decreased HcVR observed in Tg6 animals. As CMS patients also show decreased HcVR, our findings might help to better understand respiratory disorders at high altitude.
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Affiliation(s)
- Sofien Laouafa
- Centre de Recherche du CHU de Québec, Pavillon St François d'Assise, Département de Pédiatrie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Elizabeth Elliot-Portal
- Centre de Recherche du CHU de Québec, Pavillon St François d'Assise, Département de Pédiatrie, Faculté de Médecine, Université Laval, Québec, QC, Canada.,Molecular biology and Biotechnology Institute, Universidad Mayor de San Andres, La Paz, Bolivia
| | - Susana Revollo
- Centre de Recherche du CHU de Québec, Pavillon St François d'Assise, Département de Pédiatrie, Faculté de Médecine, Université Laval, Québec, QC, Canada.,Molecular biology and Biotechnology Institute, Universidad Mayor de San Andres, La Paz, Bolivia
| | - Edith M Schneider Gasser
- Institute of Veterinary Physiology, Vetsuisse Faculty, and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland; and
| | - Vincent Joseph
- Centre de Recherche du CHU de Québec, Pavillon St François d'Assise, Département de Pédiatrie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Nicolas Voituron
- Université Paris 13, Sorbonne Paris Cité, UFR SMBH, Laboratoire "Hypoxie et poumons," Bobigny, France
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland; and.,Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru
| | - Jorge Soliz
- Centre de Recherche du CHU de Québec, Pavillon St François d'Assise, Département de Pédiatrie, Faculté de Médecine, Université Laval, Québec, QC, Canada;
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Villafuerte FC, Corante N. Chronic Mountain Sickness: Clinical Aspects, Etiology, Management, and Treatment. High Alt Med Biol 2016; 17:61-9. [PMID: 27218284 PMCID: PMC4913504 DOI: 10.1089/ham.2016.0031] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Villafuerte, Francisco C., and Noemí Corante. Chronic mountain sickness: clinical aspects, etiology, management, and treatment. High Alt Med Biol. 17:61–69, 2016.—Millions of people worldwide live at a high altitude, and a significant number are at risk of developing Chronic Mountain Sickness (CMS), a progressive incapacitating syndrome caused by lifelong exposure to hypoxia. CMS is characterized by severe symptomatic excessive erythrocytosis (EE; Hb ≥19 g/dL for women and Hb ≥21 g/dL for men) and accentuated hypoxemia, which are frequently associated with pulmonary hypertension. In advanced cases, the condition may evolve to cor pulmonale and congestive heart failure. Current knowledge indicates a genetic predisposition to develop CMS. However, there are important risk factors and comorbidities that may trigger and aggravate the condition. Thus, appropriate medical information on CMS is necessary to provide adequate diagnosis and healthcare to high-altitude inhabitants. After reviewing basic clinical aspects of CMS, including its definition, diagnosis, and common clinical findings, we discuss aspects of its etiology, and address its epidemiology, risk factors, and treatment.
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Affiliation(s)
- Francisco C Villafuerte
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia , Lima, Perú
| | - Noemí Corante
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia , Lima, Perú
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Menuet C, Khemiri H, de la Poëze d'Harambure T, Gestreau C. Polycythemia and high levels of erythropoietin in blood and brain blunt the hypercapnic ventilatory response in adult mice. Am J Physiol Regul Integr Comp Physiol 2016; 310:R979-91. [PMID: 26936784 DOI: 10.1152/ajpregu.00474.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/26/2016] [Indexed: 11/22/2022]
Abstract
Changes in arterial Po2, Pco2, and pH are the strongest stimuli sensed by peripheral and central chemoreceptors to adjust ventilation to the metabolic demand. Erythropoietin (Epo), the main regulator of red blood cell production, increases the hypoxic ventilatory response, an effect attributed to the presence of Epo receptors in both carotid bodies and key brainstem structures involved in integration of peripheral inputs and control of breathing. However, it is not known whether Epo also has an effect on the hypercapnic chemoreflex. In a first attempt to answer this question, we tested the hypothesis that Epo alters the ventilatory response to increased CO2 levels. Basal ventilation and hypercapnic ventilatory response (HCVR) were recorded from control mice and from two transgenic mouse lines constitutively expressing high levels of human Epo in brain only (Tg21) or in brain and plasma (Tg6), the latter leading to polycythemia. To tease apart the potential effects of polycythemia and levels of plasma Epo in the HCVR, control animals were injected with an Epo analog (Aranesp), and Tg6 mice were treated with the hemolytic agent phenylhydrazine after splenectomy. Ventilatory parameters measured by plethysmography in conscious mice were consistent with data from electrophysiological recordings in anesthetized animals and revealed a blunted HCVR in Tg6 mice. Polycythemia alone and increased levels of plasma Epo blunt the HCVR. In addition, Tg21 mice with an augmented level of cerebral Epo also had a decreased HCVR. We discuss the potential implications of these findings in several physiopathological conditions.
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27
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Pathophysiology of central sleep apneas. Sleep Breath 2016; 20:467-82. [DOI: 10.1007/s11325-015-1290-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 11/10/2015] [Accepted: 11/23/2015] [Indexed: 11/26/2022]
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Rimoldi SF, Rexhaj E, Villena M, Salmon CS, Allemann Y, Scherrer U, Sartori C. Novel Insights into Cardiovascular Regulation in Patients with Chronic Mountain Sickness. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 903:83-100. [PMID: 27343090 DOI: 10.1007/978-1-4899-7678-9_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Studies of high-altitude populations, and in particular of maladapted subgroups, may provide important insight into underlying mechanisms involved in the pathogenesis of hypoxemia-related disease in general. Chronic mountain sickness (CMS) is a major public health problem in mountainous regions of the world affecting many millions of high-altitude dwellers. It is characterized by exaggerated chronic hypoxemia, erythrocytosis, and mild pulmonary hypertension. In later stages these patients often present with right heart failure and are predisposed to systemic cardiovascular disease, but the underlying mechanisms are poorly understood. Here, we present recent new data providing insight into underlying mechanisms that may cause these complications.
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Affiliation(s)
- Stefano F Rimoldi
- Department of Cardiology, Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland.
- Department of Internal Medicine, Botnar Center for Extreme Medicine, University Hospital, Lausanne, CHUV, Switzerland.
| | - Emrush Rexhaj
- Department of Cardiology, Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland
- Department of Internal Medicine, Botnar Center for Extreme Medicine, University Hospital, Lausanne, CHUV, Switzerland
| | | | | | - Yves Allemann
- Department of Cardiology, Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland
| | - Urs Scherrer
- Department of Cardiology, Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland
- Department of Internal Medicine, Botnar Center for Extreme Medicine, University Hospital, Lausanne, CHUV, Switzerland
- Departamento de Biología, Facultad de Ciencias, Universidad de Tarapacá, Arica, Chile
| | - Claudio Sartori
- Department of Internal Medicine, Botnar Center for Extreme Medicine, University Hospital, Lausanne, CHUV, Switzerland
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Abstract
Hypoxia induces several responses at cardiovascular, pulmonary and reproductive levels, which may lead to chronic diseases. This is relevant in human populations exposed to high altitude (HA), in either chronic continuous (permanent inhabitants) or intermittent fashion (HA workers, tourists and mountaineers). In Chile, it is estimated that 1.000.000 people live at highlands and more than 55.000 work in HA shifts. Initial responses to hypoxia are compensatory and induce activation of cardioprotective mechanisms, such as those seen under intermittent hypobaric (IH) hypoxia, events that could mediate preconditioning. However, whenever hypoxia is prolonged, the chronic activation of cellular responses induces long-lasting modifications that may result in acclimatization or produce maladaptive changes with increase in cardiovascular risk. HA exposure during pregnancy induces hypoxia and oxidative stress, which in turn may promote cellular responses and epigenetic modifications resulting in severe impairment in growth and development. Sadly, this condition is accompanied with an increased fetal and neonatal morbi-mortality. Further, developmental hypoxia may program cardio-pulmonary circulations later in postnatal life, ending in vascular structural and functional alterations with augmented risk on pulmonary and cardiovascular failure. Additionally, permanent HA inhabitants have augmented risk and prevalence of chronic hypoxic pulmonary hypertension, right ventricular hypertrophy and cardiopulmonary remodeling. Similar responses are seen in adults that are intermittently exposed to chronic hypoxia (CH) such as shift workers in HA areas. The mechanisms involved determining the immediate, short and long-lasting effects are still unclear. For several years, the study of the responses to hypoxic insults and pharmacological targets has been the motivation of our group. This review describes some of the mechanisms underlying hypoxic responses and potential therapeutic approaches with antioxidants such as melatonin, ascorbate, omega 3 (Ω3) or compounds that increase the nitric oxide (NO) bioavailability.
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León-Velarde F, Villafuerte FC. Con: All dwellers at high altitude are persons of impaired physical and mental powers: the view from the Andes. High Alt Med Biol 2014; 14:212-3. [PMID: 24067177 DOI: 10.1089/ham.2013.1039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Fabiola León-Velarde
- Universidad Peruana Cayetano Heredia, Facultad de Ciencias y Filosofía, Departmento de Ciencias Biológicas y Fisiológicas , Lima, Perú
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31
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Abstract
Carbonic anhydrase (CA) inhibitors, particularly acetazolamide, have been used at high altitude for decades to prevent or reduce acute mountain sickness (AMS), a syndrome of symptomatic intolerance to altitude characterized by headache, nausea, fatigue, anorexia and poor sleep. Principally CA inhibitors act to further augment ventilation over and above that stimulated by the hypoxia of high altitude by virtue of renal and endothelial cell CA inhibition which oppose the hypocapnic alkalosis resulting from the hypoxic ventilatory response (HVR), which acts to limit the full expression of the HVR. The result is even greater arterial oxygenation than that driven by hypoxia alone and greater altitude tolerance. The severity of several additional diseases of high attitude may also be reduced by acetazolamide, including high altitude cerebral edema (HACE), high altitude pulmonary edema (HAPE) and chronic mountain sickness (CMS), both by its CA-inhibiting action as described above, but also by more recently discovered non-CA inhibiting actions, that seem almost unique to this prototypical CA inhibitor and are of most relevance to HAPE. This chapter will relate the history of CA inhibitor use at high altitude, discuss what tissues and organs containing carbonic anhydrase play a role in adaptation and maladaptation to high altitude, explore the role of the enzyme and its inhibition at those sites for the prevention and/or treatment of the four major forms of illness at high altitude.
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Affiliation(s)
- Erik R Swenson
- VA Puget Sound Health Care System and Department of Medicine, University of Washington, Seattle, WA, USA,
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Ainslie PN, Lucas SJ, Burgess KR. Breathing and sleep at high altitude. Respir Physiol Neurobiol 2013; 188:233-56. [DOI: 10.1016/j.resp.2013.05.020] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 05/04/2013] [Accepted: 05/16/2013] [Indexed: 10/26/2022]
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Naeije R, Vanderpool R. Pulmonary Hypertension and Chronic Mountain Sickness. High Alt Med Biol 2013; 14:117-25. [DOI: 10.1089/ham.2012.1124] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Robert Naeije
- Department of Pathophysiology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Rebecca Vanderpool
- Department of Pathophysiology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
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Maestri R, Bruschi C, Pinna GD. A computerized integrated system for the assessment of central and peripheral chemoreflex sensitivity. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2013; 110:58-65. [PMID: 23046682 DOI: 10.1016/j.cmpb.2012.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 09/15/2012] [Indexed: 06/01/2023]
Abstract
The assessment of chemoreflex sensitivity (CRS) is of major importance in studies investigating the adaptation of ventilation to the needs of human body. Increased sensitivity of chemoreceptors to both hypoxia and hypercapnia has recently been shown to be a powerful and independent prognosticator in heart failure (HF) patients, thus highlighting the importance of the assessment of CRS also in the clinical setting. In spite of this, the measurement of CRS is currently limited to the research setting. One possible reason might be the lack of suitable commercial equipments. On the basis of these considerations, we designed a system to carry out a comprehensive assessment of CRS, including both central and peripheral chemoreceptors. The system is based on the integration of different commercial devices and is entirely managed by a custom software written in Matlab language. The main features of our system are: (1) the implementation of standard methods (the Read's rebreathing test, the CO2 single breath test and the transient hypoxia test) suitable for both pathological and healthy subjects, (2) data quality assurance and reduction of subjective judgment in the analysis through advanced analysis procedures and statistical outliers rejection, and (3) full interactive control of every step of the recording and analysis procedures. The system is currently used in our Institution in the assessment of CRS in HF patients, chronic obstructive pulmonary disease patients and healthy subjects. It has proven to be very effective and easy to use even by clinical personnel without a specific background in respiratory function assessment.
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Affiliation(s)
- Roberto Maestri
- Department of Biomedical Engineering, S. Maugeri Foundation--IRCCS, Scientific Institute of Montescano, Montescano (PV), Italy.
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36
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Julian CG, Vargas E, Gonzales M, Dávila RD, Ladenburger A, Reardon L, Schoo C, Powers RW, Lee-Chiong T, Moore LG. Sleep-disordered breathing and oxidative stress in preclinical chronic mountain sickness (excessive erythrocytosis). Respir Physiol Neurobiol 2013; 186:188-96. [PMID: 23380170 DOI: 10.1016/j.resp.2013.01.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 01/21/2013] [Accepted: 01/22/2013] [Indexed: 11/26/2022]
Abstract
Chronic mountain sickness (CMS) is considered to be a loss of ventilatory acclimatization to high altitude (>2500m) resulting in marked arterial hypoxemia and polycythemia. This case-control study explores the possibility that sleep-disordered breathing (SDB) and associated oxidative stress contribute to the etiology of CMS. Nocturnal respiratory and [Formula: see text] patterns were measured using standard polysomnography techniques and compared between male high-altitude residents (aged 18-25) with preclinical CMS (excessive erythrocytosis (EE), n=20) and controls (n=19). Measures of oxidative stress and antioxidant status included isoprostanes (8-iso-PGF2alpha), superoxide dismutase and ascorbic acid. EE cases had a greater apnea-hypopnea index, a higher frequency of apneas (central and obstructive) and hypopneas during REM sleep, and lower nocturnal [Formula: see text] compared to controls. 8-iso-PGF2alpha was greater in EE than controls, negatively associated with nocturnal [Formula: see text] , and positively associated with hemoglobin concentration. Mild sleep-disordered breathing and oxidative stress are evident in preclinical CMS, suggesting that the resolution of nocturnal hypoxemia or antioxidant treatment may prevent disease progression.
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Affiliation(s)
- Colleen Glyde Julian
- Altitude Research Center, Department of Emergency Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA.
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Ge RL, Mo VY, Januzzi JL, Jin G, Yang Y, Han S, Wood MJ, Levine BD. B-type natriuretic peptide, vascular endothelial growth factor, endothelin-1, and nitric oxide synthase in chronic mountain sickness. Am J Physiol Heart Circ Physiol 2011; 300:H1427-33. [PMID: 21217075 DOI: 10.1152/ajpheart.00366.2010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The pathogenesis of chronic mountain sickness (CMS) may involve vasoactive peptides. The aim of this study was to investigate associations between CMS and levels of B-type natriuretic peptide (BNP), vascular endothelial growth factor (VEGF), endothelin-1 (ET-1), and endothelial nitric oxide synthase (eNOS). A total of 24 patients with CMS and 50 control subjects residing at 4,300 m participated in this study. Mean pulmonary arterial pressure (mPAP) was measured by echocardiography. Serum BNP, VEGF, ET-1, and eNOS were measured. Receiver operator characteristic curves to assess the balance of sensitivity and specificity for CMS were constructed. As a result, patients with CMS had significantly greater mPAP compared with controls and had lower arterial O(2) saturation (Sa(O(2))). Both BNP and ET-1 correlated positively with mPAP and negatively with Sa(O(2)), whereas serum VEGF levels were inversely correlated with Sa(O(2)); eNOS correlated negatively with mPAP and positively with Sa(O(2)). Median concentrations of BNP were greater in patients with CMS compared with those without CMS: 369 pg/ml [interquartile range (IQR) = 336-431] vs. 243 pg/ml (IQR = 216-279); P < 0.001. Similarly, concentrations of VEGF [543 pg/ml (IQR = 446-546) vs. 243 pg/ml (IQR = 216-279); P < 0.001] and ET-1 [14.7 pg/ml (IQR = 12.5-17.9) vs. 11.1 pg/ml (IQR = 8.7-13.9); P = 0.05] were higher in those with CMS compared with those without, whereas eNOS levels were lower in those with CMS [8.90 pg/ml (IQR 7.59-10.8) vs. 11.2 pg/ml (9.13-13.1); P < 0.001]. The areas under the receiver operator characteristic curves for diagnosis of CMS were 0.91, 0.93, 0.77, and 0.74 for BNP, VEGF, ET-1, and eNOS, respectively. In age- and biomarker-adjusted logistic regression, BNP and VEGF were positively predictive of CMS, whereas eNOS was inversely predictive. In conclusion, severe chronic hypoxemia and consequent pulmonary hypertension in patients with CMS may stimulate release of natriuretic peptides and angiogenic cytokines. These vasoactive peptides may play an important role in the pathogenesis and clinical expression of CMS and may indicate potential prognostic factors in CMS that could serve as targets for therapeutic trials or clinical decision making.
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Affiliation(s)
- Ri-Li Ge
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.
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38
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Abstract
Chronic Mountain Sickness (CMS) is an important high-altitude (HA) pathology in most mountainous regions of the world. Although its most characteristic sign is excessive erytrocytosis (EE), in the more severe stages of the disease, high-altitude pulmonary hypertension (HAPH), with remodeling of pulmonary arterioles and right ventricular enlargement is commonly found. The degree of ventricular hypertrophy depends on the vasoconstrictor pulmonary response, the intensity of vascular resistance and the level of altitude, and therefore on the degree of hypoxemia. This chapter briefly summarizes the existing data regarding the clinical and pathophysiological features of the cardiopulmonary system in CMS, with emphasis in findings from research in the Andes. The literature shows variability in cardiac output values in CMS, which might be related to the degree of EE. Recent findings have shown that cardiac output (l/min) is lower in CMS when compared with sea-level (SL) dwellers. Mean pulmonary acceleration time (ms) is significantly lower in CMS subjects than in SL and HA natives, and pulmonary vascular resistance index (Wood units) is higher in CMS and HA natives when compared with SL dwellers. Systemic blood pressure has similar values in CMS patients and healthy HA natives, but some differences arise in its control mechanisms. Although CMS individuals have a less effective vasoconstrictor reflex, their tolerance to orthostatic stress is similar to that of healthy HA natives which might be explained in terms of the larger blood volume present in CMS subjects. At present research is directed to design strategies on pharmacological intervention for CMS treatment. Recently, a clinical trial with acetazolamide, in patients with CMS has proven to be effective in increasing mean pulmonary acceleration time and decreasing pulmonary vascular resistance index, which might be indirectly due the reduction of hematocrit.
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Slessarev M, Prisman E, Ito S, Watson RR, Jensen D, Preiss D, Greene R, Norboo T, Stobdan T, Diskit D, Norboo A, Kunzang M, Appenzeller O, Duffin J, Fisher JA. Differences in the control of breathing between Himalayan and sea-level residents. J Physiol 2010; 588:1591-606. [PMID: 20194122 DOI: 10.1113/jphysiol.2009.185504] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We compared the control of breathing of 12 male Himalayan highlanders with that of 21 male sea-level Caucasian lowlanders using isoxic hyperoxic ( = 150 mmHg) and hypoxic ( = 50 mmHg) Duffin's rebreathing tests. Highlanders had lower mean +/- s.e.m. ventilatory sensitivities to CO(2) than lowlanders at both isoxic tensions (hyperoxic: 2.3 +/- 0.3 vs. 4.2 +/- 0.3 l min(1) mmHg(1), P = 0.021; hypoxic: 2.8 +/- 0.3 vs. 7.1 +/- 0.6 l min(1) mmHg(1), P < 0.001), and the usual increase in ventilatory sensitivity to CO(2) induced by hypoxia in lowlanders was absent in highlanders (P = 0.361). Furthermore, the ventilatory recruitment threshold (VRT) CO(2) tensions in highlanders were lower than in lowlanders (hyperoxic: 33.8 +/- 0.9 vs. 48.9 +/- 0.7 mmHg, P < 0.001; hypoxic: 31.2 +/- 1.1 vs. 44.7 +/- 0.7 mmHg, P < 0.001). Both groups had reduced ventilatory recruitment thresholds with hypoxia (P < 0.001) and there were no differences in the sub-threshold ventilations (non-chemoreflex drives to breathe) between lowlanders and highlanders at both isoxic tensions (P = 0.982), with a trend for higher basal ventilation during hypoxia (P = 0.052). We conclude that control of breathing in Himalayan highlanders is distinctly different from that of sea-level lowlanders. Specifically, Himalayan highlanders have decreased central and absent peripheral sensitivities to CO(2). Their response to hypoxia was heterogeneous, with the majority decreasing their VRT indicating either a CO(2)-independent increase in activity of peripheral chemoreceptor or hypoxia-induced increase in [H(+)] at the central chemoreceptor. In some highlanders, the decrease in VRT was accompanied by an increase in sensitivity to CO(2), while in others VRT remained unchanged and their sub-threshold ventilations increased, although these were not statistically significant.
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Affiliation(s)
- M Slessarev
- Department of Anesthesia, University Health Network, University of Toronto, Toronto, Canada
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40
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Gestreau C, Heitzmann D, Thomas J, Dubreuil V, Bandulik S, Reichold M, Bendahhou S, Pierson P, Sterner C, Peyronnet-Roux J, Benfriha C, Tegtmeier I, Ehnes H, Georgieff M, Lesage F, Brunet JF, Goridis C, Warth R, Barhanin J. Task2 potassium channels set central respiratory CO2 and O2 sensitivity. Proc Natl Acad Sci U S A 2010; 107:2325-30. [PMID: 20133877 PMCID: PMC2836670 DOI: 10.1073/pnas.0910059107] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Task2 K(+) channel expression in the central nervous system is surprisingly restricted to a few brainstem nuclei, including the retrotrapezoid (RTN) region. All Task2-positive RTN neurons were lost in mice bearing a Phox2b mutation that causes the human congenital central hypoventilation syndrome. In plethysmography, Task2(-/-) mice showed disturbed chemosensory function with hypersensitivity to low CO(2) concentrations, leading to hyperventilation. Task2 probably is needed to stabilize the membrane potential of chemoreceptive cells. In addition, Task2(-/-) mice lost the long-term hypoxia-induced respiratory decrease whereas the acute carotid-body-mediated increase was maintained. The lack of anoxia-induced respiratory depression in the isolated brainstem-spinal cord preparation suggested a central origin of the phenotype. Task2 activation by reactive oxygen species generated during hypoxia could silence RTN neurons, thus contributing to respiratory depression. These data identify Task2 as a determinant of central O(2) chemoreception and demonstrate that this phenomenon is due to the activity of a small number of neurons located at the ventral medullary surface.
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MESH Headings
- Animals
- Animals, Newborn
- Brain Stem/pathology
- Brain Stem/physiology
- Brain Stem/physiopathology
- Carbon Dioxide/physiology
- Chemoreceptor Cells/pathology
- Chemoreceptor Cells/physiology
- Disease Models, Animal
- Female
- Homeodomain Proteins/genetics
- Homeodomain Proteins/physiology
- Humans
- Hypercapnia/physiopathology
- Hypoxia/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Mutant Strains
- Oxygen/physiology
- Plethysmography, Whole Body
- Potassium Channels, Tandem Pore Domain/deficiency
- Potassium Channels, Tandem Pore Domain/genetics
- Potassium Channels, Tandem Pore Domain/physiology
- Pregnancy
- Respiratory Center/physiology
- Respiratory Physiological Phenomena
- Sleep Apnea, Central/etiology
- Sleep Apnea, Central/genetics
- Sleep Apnea, Central/physiopathology
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/physiology
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Affiliation(s)
- Christian Gestreau
- Department of Neurovegetative Physiology, Centre National de la Recherche Scientifique, Université Paul Cézanne, 13397 Marseille, France;
| | - Dirk Heitzmann
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany;
- Department of Internal Medicine, Nephrologyand Rheumatology, University of Muenster, 48149 Muenster, Germany;
| | - Joerg Thomas
- Department of Anaesthesiology, University of Ulm, 89075 Ulm, Germany;
| | - Véronique Dubreuil
- Département de Biologie, Ecole Normale Supérieure, Centre National de la Recherche Scientifique, 75005 Paris, France; and
| | - Sascha Bandulik
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany;
| | - Markus Reichold
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany;
| | - Saïd Bendahhou
- Transport Ionique Aspects Normaux et Pathologiques, Centre National de la Recherche Scientifique, and Faculté des Sciences, Université de Nice Sophia Antipolis, 06108 Nice Cedex, France
| | - Patricia Pierson
- Transport Ionique Aspects Normaux et Pathologiques, Centre National de la Recherche Scientifique, and Faculté des Sciences, Université de Nice Sophia Antipolis, 06108 Nice Cedex, France
| | - Christina Sterner
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany;
| | - Julie Peyronnet-Roux
- Department of Neurovegetative Physiology, Centre National de la Recherche Scientifique, Université Paul Cézanne, 13397 Marseille, France;
| | - Chérif Benfriha
- Department of Neurovegetative Physiology, Centre National de la Recherche Scientifique, Université Paul Cézanne, 13397 Marseille, France;
| | - Ines Tegtmeier
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany;
| | - Hannah Ehnes
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany;
| | - Michael Georgieff
- Department of Anaesthesiology, University of Ulm, 89075 Ulm, Germany;
| | - Florian Lesage
- Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, and Université de Nice Sophia Antipolis, 06560 Valbonne, France;
| | - Jean-Francois Brunet
- Département de Biologie, Ecole Normale Supérieure, Centre National de la Recherche Scientifique, 75005 Paris, France; and
| | - Christo Goridis
- Département de Biologie, Ecole Normale Supérieure, Centre National de la Recherche Scientifique, 75005 Paris, France; and
| | - Richard Warth
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany;
| | - Jacques Barhanin
- Transport Ionique Aspects Normaux et Pathologiques, Centre National de la Recherche Scientifique, and Faculté des Sciences, Université de Nice Sophia Antipolis, 06108 Nice Cedex, France
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Stuber T, Sartori C, Schwab M, Jayet PY, Rimoldi SF, Garcin S, Thalmann S, Spielvogel H, Salmòn CS, Villena M, Scherrer U, Allemann Y. Exaggerated pulmonary hypertension during mild exercise in chronic mountain sickness. Chest 2009; 137:388-92. [PMID: 19783668 DOI: 10.1378/chest.09-1355] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Chronic mountain sickness (CMS) is an important public health problem and is characterized by exaggerated hypoxemia, erythrocytosis, and pulmonary hypertension. While pulmonary hypertension is a leading cause of morbidity and mortality in patients with CMS, it is relatively mild and its underlying mechanisms are not known. We speculated that during mild exercise associated with daily activities, pulmonary hypertension in CMS is much more pronounced. METHODS We estimated pulmonary artery pressure by using echocardiography at rest and during mild bicycle exercise at 50 W in 30 male patients with CMS and 32 age-matched, healthy control subjects who were born and living at an altitude of 3,600 m. RESULTS The modest, albeit significant difference of the systolic right-ventricular-to-right-atrial pressure gradient between patients with CMS and controls at rest (30.3 +/- 8.0 vs 25.4 +/- 4.5 mm Hg, P 5 .002) became more than three times larger during mild bicycle exercise (56.4 +/- 19.0 vs 39.8 +/- 8.0 mm Hg, P < .001). CONCLUSIONS Measurements of pulmonary artery pressure at rest greatly underestimate pulmonary artery pressure during daily activity in patients with CMS. The marked pulmonary hypertension during mild exercise associated with daily activity may explain why this problem is a leading cause of morbidity and mortality in patients with CMS.
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Affiliation(s)
- Thomas Stuber
- University Hospital of Bern, Cardiology, Bern, Switzerland
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Maignan M, Rivera-Ch M, Privat C, Leòn-Velarde F, Richalet JP, Pham I. Pulmonary Pressure and Cardiac Function in Chronic Mountain Sickness Patients. Chest 2009; 135:499-504. [DOI: 10.1378/chest.08-1094] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Richalet JP, Rivera-Ch M, Maignan M, Privat C, Pham I, Macarlupu JL, Petitjean O, León-Velarde F. Acetazolamide for Monge's Disease. Am J Respir Crit Care Med 2008; 177:1370-6. [DOI: 10.1164/rccm.200802-196oc] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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44
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Moore LG, Niermeyer S, Vargas E. Does chronic mountain sickness (CMS) have perinatal origins? Respir Physiol Neurobiol 2007; 158:180-9. [PMID: 17706469 DOI: 10.1016/j.resp.2007.06.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 06/08/2007] [Accepted: 06/29/2007] [Indexed: 11/30/2022]
Abstract
Chronic mountain sickness (CMS) occurs in approximately 10% of male high-altitude residents. It is characterized by hypoventilation and hypoxemia but its underlying cause remains unknown. We hypothesized that CMS' origins reside in exaggerated perinatal hypoxia that serves, in turn, to impair the development of pulmonary structure and/or respiratory control. As a preliminary test, we asked if birth weights were low and other signs of perinatal hypoxia were present in 12 young men with excessive erythrocytosis (EE, Hb>or=18.3g/dL), a condition thought to be a preclinical phase of CMS. Their birth weights were uniformly low (2571+/-243g) and all but one demonstrated perinatal hypoxia as manifested either by being small for their gestational age (SGA, 8%), preterm (67%), born to a preeclamptic (PE) mother (50%), or diagnosed with neonatal hypoxia (83%). Impaired growth in utero has been shown to raise susceptibility to adult disease; these are the first data to demonstrate a possible influence of reduced fetal growth and/or exaggerated perinatal hypoxia on increasing the susceptibility to CMS. Future studies, with more detailed testing in larger samples of control as well as EE subjects, with longitudinal follow-up, are required to determine the role of perinatal hypoxia in the development of CMS.
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Affiliation(s)
- Lorna G Moore
- Altitude Research Center, Department of Surgery/Emergency Medicine, University of Colorado at Denver and Health Sciences Center, Denver, CO 80262, USA.
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45
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Powell FL. The influence of chronic hypoxia upon chemoreception. Respir Physiol Neurobiol 2007; 157:154-61. [PMID: 17291837 PMCID: PMC1964780 DOI: 10.1016/j.resp.2007.01.009] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 01/15/2007] [Accepted: 01/15/2007] [Indexed: 01/07/2023]
Abstract
Carotid body chemoreceptors are essential for time-dependent changes in ventilatory control during chronic hypoxia. Early theories of ventilatory acclimatization to hypoxia focused on time-dependent changes in known ventilatory stimuli, such as small changes in arterial pH that may play a significant role in some species. However, plasticity in the cellular and molecular mechanisms of carotid body chemoreception play a major role in ventilatory acclimatization to hypoxia in all species studied. Chronic hypoxia causes changes in (a) ion channels (potassium, sodium, calcium) to increase glomus cell excitability, and (b) neurotransmitters (dopamine, acetylcholine, ATP) and neuromodulators (endothelin-1) to increase carotid body afferent activity for a given PO(2) and optimize O(2)-sensitivity. O(2)-sensing heme-containing molecules in the carotid body have not been studied in chronic hypoxia. Plasticity in medullary respiratory centers processing carotid body afferent input also contributes to ventilatory acclimatization to hypoxia. It is not known if the same mechanisms occur in patients with chronic hypoxemia from lung disease or high altitude natives.
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Affiliation(s)
- Frank L Powell
- Department of Medicine and White Mountain Research Station, University of California, San Diego, La Jolla, CA 92093-0623, USA.
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