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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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Titz A, Schneider S, Mueller J, Mayer L, Lichtblau M, Ulrich S. Symposium review: high altitude travel with pulmonary vascular disease. J Physiol 2024. [PMID: 38780974 DOI: 10.1113/jp284585] [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: 06/18/2023] [Accepted: 04/26/2024] [Indexed: 05/25/2024] Open
Abstract
Pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension are the main precapillary forms of pulmonary hypertension (PH) summarized as pulmonary vascular diseases (PVD). PVDs are characterized by exertional dyspnoea and oxygen desaturation, and reduced quality of life and survival. Medical therapies improve life expectancy and physical performance of PVD patients, of whom many wish to participate in professional work and recreational activities including traveling to high altitude. The exposure to the hypobaric hypoxic environment of mountain regions incurs the risk of high altitude adverse events (AEHA) due to severe hypoxaemia exacerbating symptoms and further increase in pulmonary artery pressure, which may lead to right heart decompensation. Recent prospective and randomized trials show that altitude-induced hypoxaemia, pulmonary haemodynamic changes and impairment of exercise performance in PVD patients are in the range found in healthy people. The vast majority of optimally treated stable PVD patients who do not require long-term oxygen therapy at low altitude can tolerate short-term exposure to moderate altitudes up to 2500 m. PVD patients that reveal persistent severe resting hypoxaemia (S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ <80% for >30 min) at 2500 m respond well to supplemental oxygen therapy. Although there are no accurate predictors for AEHA, PVD patients with unfavourable risk profiles at low altitude, such as higher WHO functional class, lower exercise capacity with more pronounced exercise-induced desaturation and more severely impaired haemodynamics, are at increased risk of AEHA. Therefore, doctors with experience in PVD and high-altitude medicine should counsel PVD patients before any high-altitude sojourn. This review aims to summarize recent literature and clinical recommendations about PVD patients travelling to high altitude.
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Affiliation(s)
- Anna Titz
- University Hospital of Zurich, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
| | | | | | - Laura Mayer
- University Hospital of Zurich, Zurich, Switzerland
| | | | - Silvia Ulrich
- University Hospital of Zurich, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
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Santos EW, Khatoon S, Di Mise A, Zheng YM, Wang YX. Mitochondrial Dynamics in Pulmonary Hypertension. Biomedicines 2023; 12:53. [PMID: 38255160 PMCID: PMC10813473 DOI: 10.3390/biomedicines12010053] [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: 11/20/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 01/24/2024] Open
Abstract
Mitochondria are essential organelles for energy production, calcium homeostasis, redox signaling, and other cellular responses involved in pulmonary vascular biology and disease processes. Mitochondrial homeostasis depends on a balance in mitochondrial fusion and fission (dynamics). Mitochondrial dynamics are regulated by a viable circadian clock. Hypoxia and nicotine exposure can cause dysfunctions in mitochondrial dynamics, increases in mitochondrial reactive oxygen species generation and calcium concentration, and decreases in ATP production. These mitochondrial changes contribute significantly to pulmonary vascular oxidative stress, inflammatory responses, contractile dysfunction, pathologic remodeling, and eventually pulmonary hypertension. In this review article, therefore, we primarily summarize recent advances in basic, translational, and clinical studies of circadian roles in mitochondrial metabolism in the pulmonary vasculature. This knowledge may not only be crucial to fully understanding the development of pulmonary hypertension, but also greatly help to create new therapeutic strategies for treating this devastating disease and other related pulmonary disorders.
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Affiliation(s)
- Ed Wilson Santos
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA; (E.W.S.); (S.K.); (A.D.M.)
| | - Subika Khatoon
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA; (E.W.S.); (S.K.); (A.D.M.)
| | - Annarita Di Mise
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA; (E.W.S.); (S.K.); (A.D.M.)
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona, 4, 70125 Bari, Italy
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA; (E.W.S.); (S.K.); (A.D.M.)
| | - Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA; (E.W.S.); (S.K.); (A.D.M.)
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Chen X, Zhang J, Lin Y, Li Y, Wang H, Wang Z, Liu H, Hu Y, Liu L. Mechanism, prevention and treatment of cognitive impairment caused by high altitude exposure. Front Physiol 2023; 14:1191058. [PMID: 37731540 PMCID: PMC10507266 DOI: 10.3389/fphys.2023.1191058] [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: 03/21/2023] [Accepted: 06/05/2023] [Indexed: 09/22/2023] Open
Abstract
Hypobaric hypoxia (HH) characteristics induce impaired cognitive function, reduced concentration, and memory. In recent years, an increasing number of people have migrated to high-altitude areas for work and study. Headache, sleep disturbance, and cognitive impairment from HH, severely challenges the physical and mental health and affects their quality of life and work efficiency. This review summarizes the manifestations, mechanisms, and preventive and therapeutic methods of HH environment affecting cognitive function and provides theoretical references for exploring and treating high altitude-induced cognitive impairment.
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Affiliation(s)
- Xin Chen
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Jiexin Zhang
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
- Faculty of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, Hubei, China
| | - Yuan Lin
- Sichuan Xincheng Biological Co., LTD., Chengdu, Sichuan, China
| | - Yan Li
- Department of General Surgery, The 77th Army Hospital, Leshan, Sichuan, China
| | - Han Wang
- Department of Cardiology, Affiliated Hospital of Southwest Jiaotong University, The Third People’s Hospital of Chengdu, Chengdu, Sichuan, China
| | - Zhanhao Wang
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Huawei Liu
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Yonghe Hu
- Faculty of Medicine, Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Lei Liu
- Medical Research Center, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
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Burtscher J, Hohenauer E, Burtscher M, Millet GP, Egg M. Environmental and behavioral regulation of HIF-mitochondria crosstalk. Free Radic Biol Med 2023; 206:63-73. [PMID: 37385566 DOI: 10.1016/j.freeradbiomed.2023.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/05/2023] [Accepted: 06/19/2023] [Indexed: 07/01/2023]
Abstract
Reduced oxygen availability (hypoxia) can lead to cell and organ damage. Therefore, aerobic species depend on efficient mechanisms to counteract detrimental consequences of hypoxia. Hypoxia inducible factors (HIFs) and mitochondria are integral components of the cellular response to hypoxia and coordinate both distinct and highly intertwined adaptations. This leads to reduced dependence on oxygen, improved oxygen supply, maintained energy provision by metabolic remodeling and tapping into alternative pathways and increased resilience to hypoxic injuries. On one hand, many pathologies are associated with hypoxia and hypoxia can drive disease progression, for example in many cancer and neurological diseases. But on the other hand, controlled induction of hypoxia responses via HIFs and mitochondria can elicit profound health benefits and increase resilience. To tackle pathological hypoxia conditions or to apply health-promoting hypoxia exposures efficiently, cellular and systemic responses to hypoxia need to be well understood. Here we first summarize the well-established link between HIFs and mitochondria in orchestrating hypoxia-induced adaptations and then outline major environmental and behavioral modulators of their interaction that remain poorly understood.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
| | - Erich Hohenauer
- Rehabilitation and Exercise Science Laboratory (RES Lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland; International University of Applied Sciences THIM, Landquart, Switzerland; Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland; Department of Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Margit Egg
- Institute of Zoology, University of Innsbruck, Innsbruck, Austria
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Liu Y, Feng X, Tang Y, Sun Y, Pu X, Feng X. Clinical characteristics of venous thromboembolism onset from severe high altitude pulmonary edema in plateau regions. Thromb J 2023; 21:22. [PMID: 36855176 PMCID: PMC9973235 DOI: 10.1186/s12959-023-00469-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 02/20/2023] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND To investigate venous thromboembolism (VTE) in hospitalized patients with severe high altitude pulmonary edema (HAPE), we performed a single center retrospective study to evaluate its clinical characteristics, prognosis, and potential thromboprophylaxis strategies in a large referral and treatment center in plateau regions. METHODS We studied a total of 18 patients with severe HAPE from January 1, 2012 to December 31, 2021. Demographic and clinical data, laboratory data, including ultrasound scans of the lower extremities and cardiac ultrasound, and computed tomographic pulmonary angiography (CTPA) variables were obtained, and comparisons were made between groups with and without VTE. RESULTS Of the 18 patients hospitalized with severe HAPE (age 43 (range, 34-54) years, 14 [77.8%] men), 7 patients developed VTE (38.9%), including 5 with deep vein thrombosis (DVT) and pulmonary embolism (PE), 2 of whom had DVT only. Eighteen patients are all firstly rapid ascent to high altitudes which the mean altitude was 3700 m (3656-4050 m). Compared with patients who did not have VTE, patients with VTE had a longer time in hospital (13 [11, 19] versus 9 [7, 12]; P = 0.027), respiratory failure (6 [85.7%] versus 2 [18.2%]; P = 0.013), the shortened APTT (21.50 [19.00, 27.50] versus 26.30 [24.80, 30.10]; P = 0.044) and the higher level of D-dimer (7.81 [4.62, 9.60] versus 2.90 [1.75, 3.37]; P = 0.003). The proportion of thromboprophylaxis is too low in our cohort which 2 of 18 (11.1%) patients were given VTE prophylaxis. There was no statistically significant difference between the VTE and non-VTE groups (0 [0.0%] versus 2 [18.2%]; P = 0.497). CONCLUSIONS The prevalence of VTE is high in hospitalized patients with severe high altitude pulmonary edema (HAPE). Prophylaxis for venous thromboembolism may be protective in severe HAPE patients after admission. Our data seem to suggest that VTE is probably an additional prognostic factors in patients with severe HAPE.
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Affiliation(s)
- Yanmin Liu
- grid.469564.cDepartment of Cardiology, Qinghai Provincial People’s Hospital, 2 Gonghe Road, Chengdong District, Xining, Qinghai Province 810007 China ,grid.263761.70000 0001 0198 0694Suzhou Medical College of Soochow University, 199 RenAi Road, Suzhou Industrial Park, Suzhou, Jiangsu Province 215123 China
| | - Xinwei Feng
- grid.262246.60000 0004 1765 430XCollege of Medicine, Qinghai University, 16 Kunlun Road, Chengxi District, Xining, Qinghai Province 810001 China
| | - Yongxue Tang
- grid.262246.60000 0004 1765 430XCollege of Medicine, Qinghai University, 16 Kunlun Road, Chengxi District, Xining, Qinghai Province 810001 China
| | - Yanqiu Sun
- The Department of Radiology, Qinghai Provincial People's Hospital, 2 Gonghe Road, Chengdong District, Xining, Qinghai Province, 810007, China.
| | - Xiaoyan Pu
- College of Medicine, Qinghai University, 16 Kunlun Road, Chengxi District, Xining, Qinghai Province, 810001, China.
| | - Xiaokai Feng
- Department of Respiratory and Critical Care Medicine, Qinghai Provincial People's Hospital, 2 Gonghe Road, Chengdong District, Xining, Qinghai Province, 810007, China. .,Department of Respiratory and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, No. 8, Gongti South Road, Chaoyang District, Beijing, 100020, China.
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Chanana N, Palmo T, Sharma K, Kumar R, Shah B, Mahajan S, Palleda GM, Gupta MD, Kukreti R, Faruq M, Thinlas T, Graham BB, Pasha Q. Sexual Dimorphism of Dexamethasone as a Prophylactic Treatment in Pathologies Associated With Acute Hypobaric Hypoxia Exposure. Front Pharmacol 2022; 13:873867. [PMID: 35668947 PMCID: PMC9163683 DOI: 10.3389/fphar.2022.873867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 04/05/2022] [Indexed: 11/21/2022] Open
Abstract
Dexamethasone can be taken prophylactically to prevent hypobaric hypoxia-associated disorders of high-altitude. While dexamethasone-mediated protection against high-altitude disorders has been clinically evaluated, detailed sex-based mechanistic insights have not been explored. As part of our India-Leh-Dexamethasone-expedition-2020 (INDEX 2020) programme, we examined the phenotype of control (n = 14) and dexamethasone (n = 13) groups, which were airlifted from Delhi (∼225 m elevation) to Leh, Ladakh (∼3,500 m), India, for 3 days. Dexamethasone 4 mg twice daily significantly attenuated the rise in blood pressure, heart rate, pulmonary pressure, and drop in SaO2 resulting from high-altitude exposure compared to control-treated subjects. Of note, the effect of dexamethasone was substantially greater in women than in men, in whom the drug had relatively little effect. Thus, for the first time, this study shows a sex-biased regulation by dexamethasone of physiologic parameters resulting from the hypoxic environment of high-altitude, which impacts the development of high-altitude pulmonary hypertension and acute mountain sickness. Future studies of cellular contributions toward sex-specific regulation may provide further insights and preventive measures in managing sex-specific, high-altitude–related disorders.
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Affiliation(s)
- Neha Chanana
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
| | - Tsering Palmo
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
| | - Kavita Sharma
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
| | - Rahul Kumar
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Bhushan Shah
- Department of Cardiology, GB Pant Institute of Post Graduate Medical Education and Research, New Delhi, India
| | - Sudhanshu Mahajan
- Department of Cardiology, GB Pant Institute of Post Graduate Medical Education and Research, New Delhi, India
| | - Girish M. Palleda
- Department of Cardiology, GB Pant Institute of Post Graduate Medical Education and Research, New Delhi, India
| | - Mohit D. Gupta
- Department of Cardiology, GB Pant Institute of Post Graduate Medical Education and Research, New Delhi, India
| | - Ritushree Kukreti
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
| | - Mohammad Faruq
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
| | - Tashi Thinlas
- Department of Medicine, Sonam Norboo Memorial Hospital, Leh, Ladakh, India
| | - Brian B. Graham
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Qadar Pasha
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Institute of Hypoxia Research, New Delhi, India
- *Correspondence: Qadar Pasha,
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Butt AK, Patel J, Shirwany H, Mirza Q, Hoover J, Khouzam RN. Beneficial Extracardiac Effects of Cardiovascular Medications. Curr Cardiol Rev 2022; 18:e151021197270. [PMID: 34779371 PMCID: PMC9413730 DOI: 10.2174/1573403x17666211015145132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 08/10/2021] [Accepted: 08/25/2021] [Indexed: 11/22/2022] Open
Abstract
Cardiovascular diseases are the most common cause of death worldwide, with cardiovascular medications being amongst the most common medications prescribed. These medications have diverse effects on the heart, vascular system, as well as other tissues and organ systems. The extra cardiovascular effects have been found to be of use in the treatment of non-cardiovascular diseases and pathologies. Minoxidil is used to manage systemic hypertension with its well-known side effect of hirsutism used to treat alopecia and baldness. Sildenafil was originally investigated as a treatment option for systemic hypertension; however, its side effect of penile erection led to it being widely used for erectile dysfunction. Alpha-1 blockers such as terazosin are indicated to treat systemic hypertension but are more commonly used for benign prostatic hyperplasia and post-traumatic stress disorder. Beta blockers are the mainstay treatment for congestive heart failure and systemic hypertension but have been found useful to help in patients with intention tremors as well as prophylaxis of migraines. Similarly, calcium channel blockers are indicated in medical expulsion therapy for ureteric calculi in addition to their cardiovascular indications. Thiazides are commonly used for treating systemic hypertension and as diuretics. Thiazides can cause hypocalciuria and hypercalcemia. This side effect has led to thiazides being used to treat idiopathic hypercalciuria and associated nephrolithiasis. Spironolactone is commonly utilized in treating heart failure and as a diuretic for edema. It's well described anti-androgen side effects have been used for acne vulgaris and hirsutism in polycystic ovarian syndrome. This review article discusses how the various extracardiovascular effects of commonly used cardiovascular medications are put to use in managing non-cardiovascular conditions.
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Affiliation(s)
- Asra K Butt
- Department of Internal Medicine, Veteran Affairs Medical Center, Memphis, TN 38104, USA
| | - Jay Patel
- Department of Internal Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Hamid Shirwany
- University of Tennessee Health Science Center, College of Medicine, Memphis, TN 38163, USA
| | - Qasim Mirza
- Department of Medicine, Division of Pulmonary, Critical Care & Sleep Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Jonathan Hoover
- Department of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Rami N Khouzam
- Department of Medicine, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Zubieta-Calleja G, Zubieta-DeUrioste N. Acute Mountain Sickness, High Altitude Pulmonary Edema, and High Altitude Cerebral Edema: A view from the High Andes. Respir Physiol Neurobiol 2021; 287:103628. [PMID: 33545376 DOI: 10.1016/j.resp.2021.103628] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 01/27/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND Travelling to high altitude for entertainment or work is sometimes associated with acute high altitude pathologies. In the past, scientific literature from the lowlanders' point of view was mostly based on mountain climbing. Nowadays, descent is not mandatory in populated highland cities. METHODS We present how to diagnose and treat acute high altitude pathologies (hypobaric hypoxic diseases) based on 50 years of experience in both: high altitude physiology research and medical practice as clinicians, in La Paz, Bolivia (3,600 m; 11,811 ft), at the High Altitude Pulmonary and Pathology Institute (HAPPI - IPPA). RESULTS Acute Mountain Sickness, High Altitude Pulmonary Edema, and High Altitude Cerebral Edema are medical conditions faced by some travelers. These can occasionally present after flights to high altitude cities, both in lowlanders or in high altitude residents during re-entry, having spent more than 20 days at sea level. CONCLUSIONS Traveling to high altitude should not be feared as it has many benefits; Acute high altitude ascent diseases can be adequately diagnosed and treated without descent.
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Affiliation(s)
- Gustavo Zubieta-Calleja
- High Altitude Pulmonary and Pathology Institute (HAPPI-IPPA), Av. Copacabana - Prolongación # 55, La Paz, Bolivia; Department of Physiology, Shri B.M.Patil Medical College, Hospital and Research Centre, BLDE (Deemed to be University), Vijayapur, 586103, Karnataka, India.
| | - Natalia Zubieta-DeUrioste
- High Altitude Pulmonary and Pathology Institute (HAPPI-IPPA), Av. Copacabana - Prolongación # 55, La Paz, Bolivia
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Millet GP, Debevec T, Brocherie F, Burtscher M, Burtscher J. Altitude and COVID-19: Friend or foe? A narrative review. Physiol Rep 2021; 8:e14615. [PMID: 33340275 PMCID: PMC7749581 DOI: 10.14814/phy2.14615] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 12/11/2022] Open
Abstract
Recent reports suggest that high-altitude residence may be beneficial in the novel coronavirus disease (COVID-19) implicating that traveling to high places or using hypoxic conditioning thus could be favorable as well. Physiological high-altitude characteristics and symptoms of altitude illnesses furthermore seem similar to several pathologies associated with COVID-19. As a consequence, high altitude and hypoxia research and related clinical practices are discussed for potential applications in COVID-19 prevention and treatment. We summarize the currently available evidence on the relationship between altitude/hypoxia conditions and COVID-19 epidemiology and pathophysiology. The potential for treatment strategies used for altitude illnesses is evaluated. Symptomatic overlaps in the pathophysiology of COVID-19 induced ARDS and high altitude illnesses (i.e., hypoxemia, dyspnea…) have been reported but are also common to other pathologies (i.e., heart failure, pulmonary embolism, COPD…). Most treatments of altitude illnesses have limited value and may even be detrimental in COVID-19. Some may be efficient, potentially the corticosteroid dexamethasone. Physiological adaptations to altitude/hypoxia can exert diverse effects, depending on the constitution of the target individual and the hypoxic dose. In healthy individuals, they may optimize oxygen supply and increase mitochondrial, antioxidant, and immune system function. It is highly debated if these physiological responses to hypoxia overlap in many instances with SARS-CoV-2 infection and may exert preventive effects under very specific conditions. The temporal overlap of SARS-CoV-2 infection and exposure to altitude/hypoxia may be detrimental. No evidence-based knowledge is presently available on whether and how altitude/hypoxia may prevent, treat or aggravate COVID-19. The reported lower incidence and mortality of COVID-19 in high-altitude places remain to be confirmed. High-altitude illnesses and COVID-19 pathologies exhibit clear pathophysiological differences. While potentially effective as a prophylactic measure, altitude/hypoxia is likely associated with elevated risks for patients with COVID-19. Altogether, the different points discussed in this review are of possibly some relevance for individuals who aim to reach high-altitude areas. However, due to the ever-changing state of understanding of COVID-19, all points discussed in this review may be out of date at the time of its publication.
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Affiliation(s)
| | - Tadej Debevec
- Faculty of SportUniversity of LjubljanaLjubljanaSlovenia
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He X, Bai M, Guan X, Zheng J, He Y, Yuan D, Jin T, Wang L. Association between CYP2C19 gene polymorphisms and susceptibility to high-altitude pulmonary edema. THE CLINICAL RESPIRATORY JOURNAL 2020; 14:973-979. [PMID: 32621542 DOI: 10.1111/crj.13232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 05/23/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
INTRODUCTION High-altitude pulmonary edema (HAPE) is caused by the interaction of both genetic and environmental risk factors. OBJECTIVES In this study, we aimed to explore whether three single nucleotide polymorphisms (SNPs) in CYP2C19 gene influenced the HAPE susceptibility in the Chinese Han population. METHODS We recruited 238 cases and 230 controls between January 2018 and October 2018 from the Affiliated Hospital of Xizang Minzu University. The relationship between CYP2C19 gene polymorphisms and HAPE was studied by association analysis. Genotyping was performed using the Agena MassARRAY platform and the statistical analysis was performed using Chi-squared test, independent sample t test, genetic model analysis and haplotype analysis. RESULTS The main finding of our study showed that rs4494250 in CYP2C19 gene was associated with an increased risk of HAPE at age >32 years in the log-additive model (OR = 1.80, 95% CI = 1.05-3.09, P = 0.033). Also, it was observed to be associated with a reduced risk of HAPE at age ≤2 years in the dominant model (A/G-A/A vs G/G, OR = 0.55, 95% CI = 0.31-0.97, P = 0.038) and in the log-additive model (OR = 0.58, 95% CI = 0.35-0.96, P = 0.033). CONCLUSION Our findings demonstrated that CYP2C19 genetic variants were associated with risk of developing HAPE in Han Chinese population.
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Affiliation(s)
- Xue He
- Department of Medicine, Xizang Minzu University, Xianyang, China
| | - Mei Bai
- Department of Medicine, Xizang Minzu University, Xianyang, China
| | - Xiwen Guan
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Jianwen Zheng
- Department of Internal Medicine, The Affiliated Hospital of Xizang Minzu University, Xianyang, China
| | - Yongjun He
- Department of Medicine, Xizang Minzu University, Xianyang, China
| | - Dongya Yuan
- Department of Medicine, Xizang Minzu University, Xianyang, China
| | - Tianbo Jin
- Department of Medicine, Xizang Minzu University, Xianyang, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. School of Medicine, Northwest University, Xi'an, China
| | - Li Wang
- Department of Medicine, Xizang Minzu University, Xianyang, China
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Gojkovic M, Darmasaputra GS, Veliça P, Rundqvist H, Johnson RS. Deregulated hypoxic response in myeloid cells: A model for high-altitude pulmonary oedema (HAPE). Acta Physiol (Oxf) 2020; 229:e13461. [PMID: 32129933 PMCID: PMC8638671 DOI: 10.1111/apha.13461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/06/2020] [Accepted: 02/25/2020] [Indexed: 12/11/2022]
Abstract
AIM High-altitude pulmonary oedema (HAPE) is a non-cardiogenic pulmonary oedema that can occur during rapid ascent to a high-altitude environment. Classically, HAPE has been described as a condition resulting from a combination of pulmonary vasoconstriction and hypertension. Inflammation has been described as important in HAPE, although as a side effect of pulmonary oedema rather than as a causative factor. In this study, we aim to understand the role of hypoxic response in myeloid cells and its involvement in pathogenesis of HAPE. METHODS We have generated a conditional deletion in mice of the von Hippel-Lindau factor (VHL) in myeloid cells to determine the effect of a deregulated hypoxic response in pulmonary oedema. RESULTS The deletion of VHL in pulmonary myeloid cells gave rise to pulmonary oedema, increased pulmonary vascular permeability and reduced performance during exertion. These changes were accompanied by reduced stroke volume in the left ventricle. CONCLUSION In this model, we show that a deregulated myeloid cell hypoxic response can trigger some of the most important symptoms of HAPE, and thus mice with a deletion of VHL in the myeloid lineage can function as a model of HAPE.
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Affiliation(s)
- Milos Gojkovic
- Department of Cell and Molecular Biology Karolinska Institute Stockholm Sweden
| | | | - Pedro Veliça
- Department of Cell and Molecular Biology Karolinska Institute Stockholm Sweden
| | - Helene Rundqvist
- Department of Physiology and Pharmacology Karolinska Institute Stockholm Sweden
| | - Randall S. Johnson
- Department of Cell and Molecular Biology Karolinska Institute Stockholm Sweden
- Department of Physiology Development and Neuroscience University of Cambridge Cambridge UK
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Solaimanzadeh I. Acetazolamide, Nifedipine and Phosphodiesterase Inhibitors: Rationale for Their Utilization as Adjunctive Countermeasures in the Treatment of Coronavirus Disease 2019 (COVID-19). Cureus 2020; 12:e7343. [PMID: 32226695 PMCID: PMC7096066 DOI: 10.7759/cureus.7343] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Effective treatments for Coronavirus Disease 2019 (COVID-19) outbreak are urgently needed. While anti-viral approaches and vaccines are being considered immediate countermeasures are unavailable. The aim of this article is to outline a perspective on the pathophysiology of COVID-19 in the context of the currently available clinical data published in the literature. This article appreciates clinical data published on COVID-19 in the context of another respiratory illness - high altitude pulmonary edema (HAPE). Both conditions have significant similarities that portend pathophysiologic trajectories. Following this potential treatment options emerge. Both COVID-19 and HAPE exhibit a decreased ratio of arterial oxygen partial pressure to fractional inspired oxygen with concomitant hypoxia and tachypnea. There also appears to be a tendency for low carbon dioxide levels in both as well. Radiologic findings of ground glass opacities are present in up to 86% of patients with COVID-19 in addition to patchy infiltrates. Patients with HAPE also exhibit patchy infiltrates throughout the pulmonary fields, often in an asymmetric pattern and CT findings reveal increased lung markings and ground glass-like changes as well. Widespread ground-glass opacities are most commonly a manifestation of hydrostatic pulmonary edema. Similarly, elevated fibrinogen levels in both conditions are likely an epiphenomenon of edema formation rather than coagulation activation. Autopsy results of a COVID-19 fatality revealed bilateral diffuse alveolar damage associated with pulmonary edema, pro-inflammatory concentrates, and indications of early-phase acute respiratory distress syndrome (ARDS). HAPE itself is initially caused by an increase in pulmonary capillary pressure and induces altered alveolar-capillary permeability via high pulmonary artery hydrostatic pressures that lead to a protein-rich and mildly hemorrhagic edema. It appears that COVID-19 and HAPE both discretely converge on ARDS. In light of this, a countermeasure that has been shown to be effective in the analogous condition of HAPE is Acetazolamide. Acetazolamide has a myriad of effects on different organ systems, potently reduces hypoxic pulmonary vasoconstriction, improves minute ventilation and expired vital capacity. Other therapeutics to consider that are also directed towards decreased pulmonary pressure include Nifedipine and Phosphodiesterase inhibitors. This review describes COVID-19 in parallel to HAPE. Deranged respiratory parameters that are present in both conditions are highlighted. The utilization of medications found to be effective in HAPE, for the treatment of COVID-19, is proposed. Given the medical emergency of a growing contagion and the thousands of lives at stake, expedient attempts to improve survival are needed. Acetazolamide, Nifedipine and Phosphodiesterase inhibitors may be potential countermeasures.
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Aksel G, Çorbacıoğlu ŞK, Özen C. High-altitude illness: Management approach. Turk J Emerg Med 2019; 19:121-126. [PMID: 31687609 PMCID: PMC6819752 DOI: 10.1016/j.tjem.2019.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 09/15/2019] [Accepted: 09/15/2019] [Indexed: 11/30/2022] Open
Abstract
In high altitudes, usually above 2500 m, travelers are faced with decreased partial pressure of oxygen along with decreased barometric pressure. High-altitude illness, a syndrome of acute mountain sickness, high-altitude cerebral edema and high-altitude pulmonary edema, occurs due to the hypobaric hypoxia when there is inadequate acclimatization. This review provides detailed information about pathophysiology, clinical features, prevention and treatment strategies for high-altitude illness according to the current literature.
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Affiliation(s)
- Gökhan Aksel
- University of Health Sciences, Ümraniye Training and Research Hospital, Emergency Medicine Clinic, İstanbul, Turkey
| | - Şeref Kerem Çorbacıoğlu
- University of Health Sciences, Keçiören Training and Research Hospital, Emergency Medicine Clinic, Ankara, Turkey
| | - Can Özen
- Emergency Department, King's College Hospital, London, UK
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15
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Tsai SH, Huang PH, Tsai HY, Hsu YJ, Chen YW, Wang JC, Chen YH, Lin SJ. Roles of the hypoximir microRNA-424/322 in acute hypoxia and hypoxia-induced pulmonary vascular leakage. FASEB J 2019; 33:12565-12575. [PMID: 31461385 DOI: 10.1096/fj.201900564rr] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Acute mountain sickness (AMS) occurs in up to 25% of unacclimatized persons who ascend to 3000 m and can result in high-altitude pulmonary edema (HAPE). MicroRNAs (miRs) can regulate gene expression at the post-transcriptional level. Hypoxia selectively disrupts endothelial tight junction complexes through a hypoxia-inducible factor-1α (HIF-1α)-dependent mechanism. Though increased HIF-1α expression is associated with adaptation and protection from AMS development in the early stage of hypoxia, a downstream effector of HIF-1α, VEGF, can induce overzealous endothelial barrier dysfunction, increase vascular permeability, and ultimately result in HAPE and high-altitude cerebral edema. We hypothesized that the fine-tuning of downstream effectors by miRs is paramount for the preservation of endothelial barrier integrity and the prevention of vascular leakage. We found that several miRs were up-regulated in healthy volunteers who were subjected to a 3100-m height. By reviewing the literature and using online bioinformatics prediction software, we specifically selected miR-424 for further investigation because it can modulate both HIF-1α and VEGF. Hypoxia-induced miR-424 overexpression is HIF-1α dependent, and miR-424 stabilized HIF-1α, decreased VEGF expression, and promoted vascular endothelial cadherin phosphorylation. In addition, hypoxia resulted in endothelial barrier dysfunction with increased permeability; miR-424 thus attenuated hypoxia-induced endothelial cell senescence and apoptosis. miR-322 knockout mice were susceptible to hypoxia-induced pulmonary vascular leakage. miR-322 mimics improved hypoxia-induced pulmonary vascular leakage in vivo. We conclude that several miRs were up-regulated in healthy adult volunteers subjected to hypobaric hypoxemia. miR-424/322 could modulate the HIF-1α-VEGF axis and prevent hypoxia-induced pulmonary vascular leakage under hypoxic conditions.-Tsai, S.-H., Huang, P.-H., Tsai, H.-Y., Hsu, Y.-J., Chen, Y.-W., Wang, J.-C., Chen, Y.-H., Lin, S.-J. Roles of the hypoximir microRNA-424/322 in acute hypoxia and hypoxia-induced pulmonary vascular leakage.
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Affiliation(s)
- Shih-Hung Tsai
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.,Department of Physiology and Biophysics, Graduate Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | - Po-Hsun Huang
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Cardiology, Department of Internal Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,Department of Critical Care Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Hsiao-Ya Tsai
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Juei Hsu
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yen-Wen Chen
- Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jen-Chun Wang
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ying-Hsin Chen
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Shing-Jong Lin
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Cardiology, Department of Internal Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,Healthcare and Services Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Taipei Heart Institute, Taipei Medical University, Taipei, Taiwan
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Molano Franco D, Nieto Estrada VH, Gonzalez Garay AG, Martí‐Carvajal AJ, Arevalo‐Rodriguez I. Interventions for preventing high altitude illness: Part 3. Miscellaneous and non-pharmacological interventions. Cochrane Database Syst Rev 2019; 4:CD013315. [PMID: 31012483 PMCID: PMC6477878 DOI: 10.1002/14651858.cd013315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND High altitude illness (HAI) is a term used to describe a group of mainly cerebral and pulmonary syndromes that can occur during travel to elevations above 2500 metres (˜ 8200 feet). Acute mountain sickness (AMS), high altitude cerebral oedema (HACE), and high altitude pulmonary oedema (HAPE) are reported as potential medical problems associated with high altitude ascent. In this, the third of a series of three reviews about preventive strategies for HAI, we assessed the effectiveness of miscellaneous and non-pharmacological interventions. OBJECTIVES To assess the clinical effectiveness and adverse events of miscellaneous and non-pharmacological interventions for preventing acute HAI in people who are at risk of developing high altitude illness in any setting. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) in January 2019. We adapted the MEDLINE strategy for searching the other databases. We used a combination of thesaurus-based and free-text search terms. We scanned the reference lists and citations of included trials and any relevant systematic reviews that we identified for further references to additional trials. SELECTION CRITERIA We included randomized controlled trials conducted in any setting where non-pharmacological and miscellaneous interventions were employed to prevent acute HAI, including preacclimatization measures and the administration of non-pharmacological supplements. We included trials involving participants who are at risk of developing high altitude illness (AMS or HACE, or HAPE, or both). We included participants with, and without, a history of high altitude illness. We applied no age or gender restrictions. We included trials where the relevant intervention was administered before the beginning of ascent. DATA COLLECTION AND ANALYSIS We used the standard methodological procedures employed by Cochrane. MAIN RESULTS We included 20 studies (1406 participants, 21 references) in this review. Thirty studies (14 ongoing, and 16 pending classification (awaiting)) will be considered in future versions of this suite of three reviews as appropriate. We report the results for the primary outcome of this review (risk of AMS) by each group of assessed interventions.Group 1. Preacclimatization and other measures based on pressureUse of simulated altitude or remote ischaemic preconditioning (RIPC) might not improve the risk of AMS on subsequent exposure to altitude, but this effect is uncertain (simulated altitude: risk ratio (RR) 1.18, 95% confidence interval (CI) 0.82 to 1.71; I² = 0%; 3 trials, 140 participants; low-quality evidence. RIPC: RR 3.0, 95% CI 0.69 to 13.12; 1 trial, 40 participants; low-quality evidence). We found evidence of improvement of this risk using positive end-expiratory pressure (PEEP), but this information was derived from a cross-over trial with a limited number of participants (OR 3.67, 95% CI 1.38 to 9.76; 1 trial, 8 participants; low-quality evidence). We found scarcity of evidence about the risk of adverse events for these interventions.Group 2. Supplements and vitaminsSupplementation of antioxidants, medroxyprogesterone, iron or Rhodiola crenulata might not improve the risk of AMS on exposure to high altitude, but this effect is uncertain (antioxidants: RR 0.58, 95% CI 0.32 to 1.03; 1 trial, 18 participants; low-quality evidence. Medroxyprogesterone: RR 0.71, 95% CI 0.48 to 1.05; I² = 0%; 2 trials, 32 participants; low-quality evidence. Iron: RR 0.65, 95% CI 0.38 to 1.11; I² = 0%; 2 trials, 65 participants; low-quality evidence. R crenulata: RR 1.00, 95% CI 0.78 to 1.29; 1 trial, 125 participants; low-quality evidence). We found evidence of improvement of this risk with the administration of erythropoietin, but this information was extracted from a trial with issues related to risk of bias and imprecision (RR 0.41, 95% CI 0.20 to 0.84; 1 trial, 39 participants; very low-quality evidence). Regarding administration of ginkgo biloba, we did not perform a pooled estimation of RR for AMS due to considerable heterogeneity between the included studies (I² = 65%). RR estimates from the individual studies were conflicting (from 0.05 to 1.03; low-quality evidence). We found scarcity of evidence about the risk of adverse events for these interventions.Group 3. Other comparisonsWe found heterogeneous evidence regarding the risk of AMS when ginkgo biloba was compared with acetazolamide (I² = 63%). RR estimates from the individual studies were conflicting (estimations from 0.11 (95% CI 0.01 to 1.86) to 2.97 (95% CI 1.70 to 5.21); low-quality evidence). We found evidence of improvement when ginkgo biloba was administered along with acetazolamide, but this information was derived from a single trial with issues associated to risk of bias (compared to ginkgo biloba alone: RR 0.43, 95% CI 0.26 to 0.71; 1 trial, 311 participants; low-quality evidence). Administration of medroxyprogesterone plus acetazolamide did not improve the risk of AMS when compared to administration of medroxyprogesterone or acetazolamide alone (RR 1.33, 95% CI 0.50 to 3.55; 1 trial, 12 participants; low-quality evidence). We found scarcity of evidence about the risk of adverse events for these interventions. AUTHORS' CONCLUSIONS This Cochrane Review is the final in a series of three providing relevant information to clinicians, and other interested parties, on how to prevent high altitude illness. The assessment of non-pharmacological and miscellaneous interventions suggests that there is heterogeneous and even contradictory evidence related to the effectiveness of these prophylactic strategies. Safety of these interventions remains as an unclear issue due to lack of assessment. Overall, the evidence is limited due to its quality (low to very low), the relative paucity of that evidence and the number of studies pending classification for the three reviews belonging to this series (30 studies either awaiting classification or ongoing). Additional studies, especially those comparing with pharmacological alternatives (such as acetazolamide) are required, in order to establish or refute the strategies evaluated in this review.
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Affiliation(s)
- Daniel Molano Franco
- Fundacion Universitaria de Ciencias de la Salud, Hospital de San JoséDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | - Víctor H Nieto Estrada
- Los Cobos Medical Centre. Grupo Investigacion GRIBOSDepartment of Critical CareBogotaBogotaColombia
| | | | | | - Ingrid Arevalo‐Rodriguez
- Hospital Universitario Ramón y Cajal (IRYCIS), CIBER Epidemiology and Public Health (CIBERESP)Clinical Biostatistics UnitCtra. Colmenar Km. 9,100MadridSpain28034
- Cochrane Associate Centre of MadridMadridSpain
- Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio Espejo, Universidad Tecnológica EquinoccialCochrane EcuadorQuitoEcuador
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Li Y, Zhang Y, Zhang Y. Research advances in pathogenesis and prophylactic measures of acute high altitude illness. Respir Med 2018; 145:145-152. [DOI: 10.1016/j.rmed.2018.11.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 09/14/2018] [Accepted: 11/06/2018] [Indexed: 12/30/2022]
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Li Y, Han J, Chen Y, Chen C, Chu B, Zhang Y. p-Coumaric acid as a prophylactic measure against normobaric hypoxia induced pulmonary edema in mice. Life Sci 2018; 211:215-223. [PMID: 30248349 DOI: 10.1016/j.lfs.2018.09.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/14/2018] [Accepted: 09/21/2018] [Indexed: 01/07/2023]
Abstract
AIMS Previous studies indicate that the anti-hypoxia effects of Tibetan Turnip (Brassica rapa ssp. rapa) were closely related to its characteristic components being p-coumaric acid (CA) and p-coumaric acid‑β‑d‑glucopyranoside (CAG). Since CAG would be converted to CA in vivo, this study aims to further examine the efficacy and mechanism of CA against pulmonary edema induced by normobaric hypoxia. MAIN METHODS Male ICR mice were assigned to the normoxia group and several hypoxia groups, given sterile water, CA or dexamethasone orally, once daily for four consecutive days. One hour after the final gavage, mice in the above hypoxia groups were put into the normobaric hypoxia chamber (9.5% O2) for 24 h while mice in normoxia group remained outside the chamber. After hypoxia exposure, lung water content (LWC), pulmonary vascular permeability, the protein content of bronchoalveolar lavage fluid (BALF), plasma total nitrate/nitrite (NOx) and endothelin-1 (ET-1) content, histological and ultra-microstructure analyses were performed. Expression of occludin was assayed by immunohistochemistry. KEY FINDINGS In a hypoxic environment of 9.5% O2, mice treated with 100 mg/kg body wt CA had significantly lower LWC and BALF protein content than mice in the hypoxia vehicle group. Meanwhile, mice in CA group showed intact lung blood-gas-barrier, increased levels of plasma total NO, decreased levels of plasma ET-1 and upregulation of occludin expression. SIGNIFICANCE CA exerts preventive effects against normobaric hypoxic pulmonary edema in mice, its mechanisms involved improving the integrity of the lung barrier, inhibiting oxidative stress and inflammation.
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Affiliation(s)
- Yunhong Li
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Jianxin Han
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Yufeng Chen
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Chun Chen
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Bingquan Chu
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China; School of Biological and Chemical Engineering, Zhejiang Provincial Key Lab for Chem & Bio Processing Technology of Farm Product, Zhejiang University of Science & Technology, Hangzhou 310023, Zhejiang, China
| | - Ying Zhang
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China.
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Simancas‐Racines D, Arevalo‐Rodriguez I, Osorio D, Franco JVA, Xu Y, Hidalgo R. Interventions for treating acute high altitude illness. Cochrane Database Syst Rev 2018; 6:CD009567. [PMID: 29959871 PMCID: PMC6513207 DOI: 10.1002/14651858.cd009567.pub2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Acute high altitude illness is defined as a group of cerebral and pulmonary syndromes that can occur during travel to high altitudes. It is more common above 2500 metres, but can be seen at lower elevations, especially in susceptible people. Acute high altitude illness includes a wide spectrum of syndromes defined under the terms 'acute mountain sickness' (AMS), 'high altitude cerebral oedema' and 'high altitude pulmonary oedema'. There are several interventions available to treat this condition, both pharmacological and non-pharmacological; however, there is a great uncertainty regarding their benefits and harms. OBJECTIVES To assess the clinical effectiveness, and safety of interventions (non-pharmacological and pharmacological), as monotherapy or in any combination, for treating acute high altitude illness. SEARCH METHODS We searched CENTRAL, MEDLINE, Embase, LILACS, ISI Web of Science, CINAHL, Wanfang database and the World Health Organization International Clinical Trials Registry Platform for ongoing studies on 10 August 2017. We did not apply any language restriction. SELECTION CRITERIA We included randomized controlled trials evaluating the effects of pharmacological and non-pharmacological interventions for individuals suffering from acute high altitude illness: acute mountain sickness, high altitude pulmonary oedema or high altitude cerebral oedema. DATA COLLECTION AND ANALYSIS Two review authors independently assessed the eligibility of study reports, the risk of bias for each and performed the data extraction. We resolved disagreements through discussion with a third author. We assessed the quality of evidence with GRADE. MAIN RESULTS We included 13 studies enrolling a total of 468 participants. We identified two ongoing studies. All studies included adults, and two studies included both teenagers and adults. The 13 studies took place in high altitude areas, mostly in the European Alps. Twelve studies included participants with acute mountain sickness, and one study included participants with high altitude pulmonary oedema. Follow-up was usually less than one day. We downgraded the quality of the evidence in most cases due to risk of bias and imprecision. We report results for the main comparisons as follows.Non-pharmacological interventions (3 studies, 124 participants)All-cause mortality and complete relief of AMS symptoms were not reported in the three included trials. One study in 64 participants found that a simulated descent of 193 millibars versus 20 millibars may reduce the average of symptoms to 2.5 vs 3.1 units after 12 hours of treatment (clinical score ranged from 0 to 11 ‒ worse; reduction of 0.6 points on average with the intervention; low quality of evidence). In addition, no complications were found with use of hyperbaric chambers versus supplementary oxygen (one study; 29 participants; low-quality evidence).Pharmacological interventions (11 trials, 375 participants)All-cause mortality was not reported in the 11 included trials. One trial found a greater proportion of participants with complete relief of AMS symptoms after 12 and 16 hours when dexamethasone was administered in comparison with placebo (47.1% versus 0%, respectively; one study; 35 participants; low quality of evidence). Likewise, when acetazolamide was compared with placebo, the effects on symptom severity was uncertain (standardized mean difference (SMD) -1.15, 95% CI -2.56 to 0.27; 2 studies, 25 participants; low-quality evidence). One trial of dexamethasone in comparison with placebo in 35 participants found a reduction in symptom severity (difference on change in the AMS score: 3.7 units reported by authors; moderate quality of evidence). The effects from two additional trials comparing gabapentin with placebo and magnesium with placebo on symptom severity at the end of treatment were uncertain. For gabapentin versus placebo: mean visual analogue scale (VAS) score of 2.92 versus 4.75, respectively; 24 participants; low quality of evidence. For magnesium versus placebo: mean scores of 9 and 10.3 units, respectively; 25 participants; low quality of evidence). The trials did not find adverse events from either treatment (low quality of evidence). One trial comparing magnesium sulphate versus placebo found that flushing was a frequent event in the magnesium sulphate arm (percentage of flushing: 75% versus 7.7%, respectively; one study; 25 participants; low quality of evidence). AUTHORS' CONCLUSIONS There is limited available evidence to determine the effects of non-pharmacological and pharmacological interventions in treating acute high altitude illness. Low-quality evidence suggests that dexamethasone and acetazolamide might reduce AMS score compared to placebo. However, the clinical benefits and harms related to these potential interventions remain unclear. Overall, the evidence is of limited practical significance in the clinical field. High-quality research in this field is needed, since most trials were poorly conducted and reported.
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Affiliation(s)
- Daniel Simancas‐Racines
- Universidad Tecnológica EquinoccialCochrane Ecuador. Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio EspejoQuitoEcuador
| | - Ingrid Arevalo‐Rodriguez
- Universidad Tecnológica EquinoccialCochrane Ecuador. Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio EspejoQuitoEcuador
- Hospital Universitario Ramon y Cajal (IRYCIS)Clinical Biostatistics UnitMadridSpain
- CIBER Epidemiology and Public Health (CIBERESP)MadridSpain
| | - Dimelza Osorio
- Universidad Tecnológica EquinoccialCochrane Ecuador. Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio EspejoQuitoEcuador
| | - Juan VA Franco
- Instituto Universitario Hospital ItalianoArgentine Cochrane CentrePotosí 4234Buenos AiresBuenos AiresArgentinaC1199ACL
| | - Yihan Xu
- Nanyang Technological UniversityWee Kim Wee School of Communication and InformationRoom 702, Building 5, #1277 Changning RoadSingapore CitySingapore637718
| | - Ricardo Hidalgo
- Universidad Tecnológica EquinoccialCochrane Ecuador. Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio EspejoQuitoEcuador
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Genome-wide association study of high-altitude pulmonary edema in a Han Chinese population. Oncotarget 2018; 8:31568-31580. [PMID: 28415562 PMCID: PMC5458230 DOI: 10.18632/oncotarget.16362] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 02/27/2017] [Indexed: 12/28/2022] Open
Abstract
A two-stage genome-wide association study (GWAS) was performed to identify and analyze genes and single nucleotide polymorphisms (SNPs) associated with high-altitude pulmonary edema (HAPE) in a Han Chinese patient population. In the first stage, DNA samples from 68 patients with recurrent HAPE were scanned using Affymetrix SNP Array 6.0 Chips, and allele frequencies were compared to those of 84 HapMap CHB samples to identify candidate SNPs. In the second stage, the 77 identified candidate SNPs were examined in an independent cohort of samples from 199 HAPE patients and 304 controls. Associations between SNPs and HAPE risk were tested using various genetic models. Of the 77 original SNPs, 7 were found to be associated with HAPE susceptibility in the second stage of the study. GO and pathway enrichment analysis of the 7 SNPs revealed 5 adjacent genes involved in various processes, including regulation of nucleoside diphosphate metabolism, thyroid hormone catabolism, and low-density lipoprotein receptor activity. These results suggest the identified SNPs and genes may contribute to the physiopathology of HAPE.
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Gonzalez Garay AG, Molano Franco D, Nieto Estrada VH, Martí‐Carvajal AJ, Arevalo‐Rodriguez I. Interventions for preventing high altitude illness: Part 2. Less commonly-used drugs. Cochrane Database Syst Rev 2018; 2018:CD012983. [PMID: 29529715 PMCID: PMC6494375 DOI: 10.1002/14651858.cd012983] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND High altitude illness (HAI) is a term used to describe a group of mainly cerebral and pulmonary syndromes that can occur during travel to elevations above 2500 metres (˜ 8200 feet). Acute mountain sickness (AMS), high altitude cerebral oedema (HACE) and high altitude pulmonary oedema (HAPE) are reported as potential medical problems associated with high altitude ascent. In this second review, in a series of three about preventive strategies for HAI, we assessed the effectiveness of five of the less commonly used classes of pharmacological interventions. OBJECTIVES To assess the clinical effectiveness and adverse events of five of the less commonly used pharmacological interventions for preventing acute HAI in participants who are at risk of developing high altitude illness in any setting. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) in May 2017. We adapted the MEDLINE strategy for searching the other databases. We used a combination of thesaurus-based and free-text search terms. We scanned the reference lists and citations of included trials and any relevant systematic reviews that we identified for further references to additional trials. SELECTION CRITERIA We included randomized controlled trials conducted in any setting where one of five classes of drugs was employed to prevent acute HAI: selective 5-hydroxytryptamine(1) receptor agonists; N-methyl-D-aspartate (NMDA) antagonist; endothelin-1 antagonist; anticonvulsant drugs; and spironolactone. We included trials involving participants who are at risk of developing high altitude illness (AMS or HACE, or HAPE, or both). We included participants with and without a history of high altitude illness. We applied no age or gender restrictions. We included trials where the relevant medication was administered before the beginning of ascent. We excluded trials using these drugs during ascent or after ascent. DATA COLLECTION AND ANALYSIS We used the standard methodological procedures employed by Cochrane. MAIN RESULTS We included eight studies (334 participants, 9 references) in this review. Twelve studies are ongoing and will be considered in future versions of this review as appropriate. We have been unable to obtain full-text versions of a further 12 studies and have designated them as 'awaiting classification'. Four studies were at a low risk of bias for randomization; two at a low risk of bias for allocation concealment. Four studies were at a low risk of bias for blinding of participants and personnel. We considered three studies at a low risk of bias for blinding of outcome assessors. We considered most studies at a high risk of selective reporting bias.We report results for the following four main comparisons.Sumatriptan versus placebo (1 parallel study; 102 participants)Data on sumatriptan showed a reduction of the risk of AMS when compared with a placebo (risk ratio (RR) = 0.43, CI 95% 0.21 to 0.84; 1 study, 102 participants; low quality of evidence). The one included study did not report events of HAPE, HACE or adverse events related to administrations of sumatriptan.Magnesium citrate versus placebo (1 parallel study; 70 participants)The estimated RR for AMS, comparing magnesium citrate tablets versus placebo, was 1.09 (95% CI 0.55 to 2.13; 1 study; 70 participants; low quality of evidence). In addition, the estimated RR for loose stools was 3.25 (95% CI 1.17 to 8.99; 1 study; 70 participants; low quality of evidence). The one included study did not report events of HAPE or HACE.Spironolactone versus placebo (2 parallel studies; 205 participants)Pooled estimation of RR for AMS was not performed due to considerable heterogeneity between the included studies (I² = 72%). RR from individual studies was 0.40 (95% CI 0.12 to 1.31) and 1.44 (95% CI 0.79 to 2.01; very low quality of evidence). No events of HAPE or HACE were reported. Adverse events were not evaluated.Acetazolamide versus spironolactone (1 parallel study; 232 participants)Data on acetazolamide compared with spironolactone showed a reduction of the risk of AMS with the administration of acetazolamide (RR = 0.36, 95% CI 0.18 to 0.70; 232 participants; low quality of evidence). No events of HAPE or HACE were reported. Adverse events were not evaluated. AUTHORS' CONCLUSIONS This Cochrane Review is the second in a series of three providing relevant information to clinicians and other interested parties on how to prevent high altitude illness. The assessment of five of the less commonly used classes of drugs suggests that there is a scarcity of evidence related to these interventions. Clinical benefits and harms related to potential interventions such as sumatriptan are still unclear. Overall, the evidence is limited due to the low number of studies identified (for most of the comparison only one study was identified); limitations in the quality of the evidence (moderate to low); and the number of studies pending classification (24 studies awaiting classification or ongoing). We lack the large and methodologically sound studies required to establish or refute the efficacy and safety of most of the pharmacological agents evaluated in this review.
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Affiliation(s)
- Alejandro G Gonzalez Garay
- National Institute of PediatricsMethodology Research UnitInsurgentes Sur 3700 ‐ CCol. Insurgentes Cuicuilco, CoyoacanMexico CityDistrito FederalMexico04530
| | - Daniel Molano Franco
- Fundacion Universitaria de Ciencias de la Salud, Hospital de San JoséDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | - Víctor H Nieto Estrada
- Fundacion Universitaria Sanitas, Colombia ClinicDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | | | - Ingrid Arevalo‐Rodriguez
- Universidad Tecnológica EquinoccialCochrane Ecuador. Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio EspejoAv. Mariscal Sucre s/n y Av. Mariana de JesúsQuitoEcuador
- Hospital Universitario Ramon y Cajal (IRYCIS)Clinical Biostatistics UnitMadridSpain
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STAT3-RXR-Nrf2 activates systemic redox and energy homeostasis upon steep decline in pO 2 gradient. Redox Biol 2017; 14:423-438. [PMID: 29078168 PMCID: PMC5680518 DOI: 10.1016/j.redox.2017.10.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 08/30/2017] [Accepted: 10/15/2017] [Indexed: 01/04/2023] Open
Abstract
Hypobaric hypoxia elicits several patho-physiological manifestations, some of which are known to be lethal. Among various molecular mechanisms proposed so far, perturbation in redox state due to imbalance between radical generation and antioxidant defence is promising. These molecular events are also related to hypoxic status of cancer cells and therefore its understanding has extended clinical advantage beyond high altitude hypoxia. In present study, however, the focus was to understand and propose a model for rapid acclimatization of high altitude visitors to enhance their performance based on molecular changes. We considered using simulated hypobaric hypoxia at some established thresholds of high altitude stratification based on known physiological effects. Previous studies have focused on the temporal aspect while overlooking the effects of varying pO2 levels during exposure to hypobaric hypoxia. The pO2 levels, indicative of altitude, are crucial to redox homeostasis and can be the limiting factor during acclimatization to hypobaric hypoxia. In this study we present the effects of acute (24h) exposure to high (3049m; pO2: 71kPa), very high (4573m; pO2: 59kPa) and extreme altitude (7620m; pO2: 40kPa) zones on lung and plasma using semi-quantitative redox specific transcripts and quantitative proteo-bioinformatics workflow in conjunction with redox stress assays. It was observed that direct exposure to extreme altitude caused 100% mortality, which turned into high survival rate after pre-exposure to 59kPa, for which molecular explanation were also found. The pO2 of 59kPa (very high altitude zone) elicits systemic energy and redox homeostatic processes by modulating the STAT3-RXR-Nrf2 trio. Finally we posit the various processes downstream of STAT3-RXR-Nrf2 and the plasma proteins that can be used to ascertain the redox status of an individual.
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Schroeder T, Piantadosi CA, Natoli MJ, Autmizguine J, Cohen-Wolkowieczs M, Hamilton KL, Bell C, Klawitter J, Christians U, Irwin DC, Noveck RJ. Safety and Ergogenic Properties of Combined Aminophylline and Ambrisentan in Hypoxia. Clin Pharmacol Ther 2017; 103:888-898. [PMID: 28857147 PMCID: PMC5947522 DOI: 10.1002/cpt.860] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 01/24/2023]
Abstract
We hypothesized that concomitant pharmacological inhibition of the endothelin and adenosine pathway is safe and improves exercise performance in hypoxic humans, via a mechanism that does not involve augmentation of blood oxygenation. To test this hypothesis, we established safety and drug interactions for aminophylline (500 mg) plus ambrisentan (5 mg) in normoxic volunteers. Subsequently, a placebo-controlled study was employed to test the combination in healthy resting and exercising volunteers at simulated altitude (4,267 m). No serious adverse events occurred. Drug interaction was minimal or absent. Aminophylline alleviated hypoxia-induced headaches. Aminophylline, ambrisentan, and their combination all significantly (P < 0.05 vs. placebo) improved submaximal hypoxic exercise performance (19.5, 20.6, and 19.1% >placebo). Single-dose ambrisentan increased blood oxygenation in resting, hypoxic subjects. We conclude that combined aminophylline and ambrisentan offer promise to safely increase exercise capacity in hypoxemic humans without relying on increasing blood oxygen availability.
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Affiliation(s)
| | - Claude A Piantadosi
- Hyperbaric Center, Duke University Medical Center, Durham, North Carolina, USA
| | - Michael J Natoli
- Hyperbaric Center, Duke University Medical Center, Durham, North Carolina, USA
| | - Julie Autmizguine
- Department of Pharmacology, University of Montreal, Montreal, Quebec, Canada
| | - Michael Cohen-Wolkowieczs
- Duke Early Phase Clinical Research Unit, Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Karyn L Hamilton
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado, USA
| | - Christopher Bell
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado, USA
| | - Jelena Klawitter
- iC42 Integrated Solutions in Clinical Research and Development, University of Colorado, Bioscience East, Aurora, Colorado, USA
| | - Uwe Christians
- iC42 Integrated Solutions in Clinical Research and Development, University of Colorado, Bioscience East, Aurora, Colorado, USA
| | - David C Irwin
- Department of Medicine, University of Colorado Denver Anschutz Campus, Aurora, Colorado, USA
| | - Robert J Noveck
- Hyperbaric Center, Duke University Medical Center, Durham, North Carolina, USA
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Nieto Estrada VH, Molano Franco D, Medina RD, Gonzalez Garay AG, Martí‐Carvajal AJ, Arevalo‐Rodriguez I. Interventions for preventing high altitude illness: Part 1. Commonly-used classes of drugs. Cochrane Database Syst Rev 2017; 6:CD009761. [PMID: 28653390 PMCID: PMC6481751 DOI: 10.1002/14651858.cd009761.pub2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND High altitude illness (HAI) is a term used to describe a group of cerebral and pulmonary syndromes that can occur during travel to elevations above 2500 metres (8202 feet). Acute hypoxia, acute mountain sickness (AMS), high altitude cerebral oedema (HACE) and high altitude pulmonary oedema (HAPE) are reported as potential medical problems associated with high altitude. In this review, the first in a series of three about preventive strategies for HAI, we assess the effectiveness of six of the most recommended classes of pharmacological interventions. OBJECTIVES To assess the clinical effectiveness and adverse events of commonly-used pharmacological interventions for preventing acute HAI. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OVID), Embase (OVID), LILACS and trial registries in January 2017. We adapted the MEDLINE strategy for searching the other databases. We used a combination of thesaurus-based and free-text terms to search. SELECTION CRITERIA We included randomized-controlled and cross-over trials conducted in any setting where commonly-used classes of drugs were used to prevent acute HAI. DATA COLLECTION AND ANALYSIS We used standard methodological procedures as expected by Cochrane. MAIN RESULTS We included 64 studies (78 references) and 4547 participants in this review, and classified 12 additional studies as ongoing. A further 12 studies await classification, as we were unable to obtain the full texts. Most of the studies were conducted in high altitude mountain areas, while the rest used low pressure (hypobaric) chambers to simulate altitude exposure. Twenty-four trials provided the intervention between three and five days prior to the ascent, and 23 trials, between one and two days beforehand. Most of the included studies reached a final altitude of between 4001 and 5000 metres above sea level. Risks of bias were unclear for several domains, and a considerable number of studies did not report adverse events of the evaluated interventions. We found 26 comparisons, 15 of them comparing commonly-used drugs versus placebo. We report results for the three most important comparisons: Acetazolamide versus placebo (28 parallel studies; 2345 participants)The risk of AMS was reduced with acetazolamide (risk ratio (RR) 0.47, 95% confidence interval (CI) 0.39 to 0.56; I2 = 0%; 16 studies; 2301 participants; moderate quality of evidence). No events of HAPE were reported and only one event of HACE (RR 0.32, 95% CI 0.01 to 7.48; 6 parallel studies; 1126 participants; moderate quality of evidence). Few studies reported side effects for this comparison, and they showed an increase in the risk of paraesthesia with the intake of acetazolamide (RR 5.53, 95% CI 2.81 to 10.88, I2 = 60%; 5 studies, 789 participants; low quality of evidence). Budenoside versus placebo (2 parallel studies; 132 participants)Data on budenoside showed a reduction in the incidence of AMS compared with placebo (RR 0.37, 95% CI 0.23 to 0.61; I2 = 0%; 2 studies, 132 participants; low quality of evidence). Studies included did not report events of HAPE or HACE, and they did not find side effects (low quality of evidence). Dexamethasone versus placebo (7 parallel studies; 205 participants)For dexamethasone, the data did not show benefits at any dosage (RR 0.60, 95% CI 0.36 to 1.00; I2 = 39%; 4 trials, 176 participants; low quality of evidence). Included studies did not report events of HAPE or HACE, and we rated the evidence about adverse events as of very low quality. AUTHORS' CONCLUSIONS Our assessment of the most commonly-used pharmacological interventions suggests that acetazolamide is an effective pharmacological agent to prevent acute HAI in dosages of 250 to 750 mg/day. This information is based on evidence of moderate quality. Acetazolamide is associated with an increased risk of paraesthesia, although there are few reports about other adverse events from the available evidence. The clinical benefits and harms of other pharmacological interventions such as ibuprofen, budenoside and dexamethasone are unclear. Large multicentre studies are needed for most of the pharmacological agents evaluated in this review, to evaluate their effectiveness and safety.
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Affiliation(s)
- Víctor H Nieto Estrada
- Fundacion Universitaria Sanitas, Colombia ClinicDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | - Daniel Molano Franco
- Fundacion Universitaria de Ciencias de la Salud, Hospital de San JoséDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | - Roger David Medina
- Fundación Universitaria de Ciencias de la SaludDivision of ResearchCarrera 19 # 8‐32Bogotá D.C.Colombia
| | - Alejandro G Gonzalez Garay
- National Institute of PediatricsMethodology Research UnitInsurgentes Sur 3700 ‐ CCol. Insurgentes Cuicuilco, CoyoacanMexico CityDistrito FederalMexico04530
| | | | - Ingrid Arevalo‐Rodriguez
- Universidad Tecnológica EquinoccialCochrane Ecuador. Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio EspejoAv. Mariscal Sucre s/n y Av. Mariana de JesúsQuitoEcuador
- Hospital Universitario Ramon y Cajal (IRYCIS)Clinical Biostatistics UnitMadridSpain
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Strand TE, Khiabani HZ, Boico A, Radiloff D, Zhao Y, Hamilton KL, Christians U, Klawitter J, Noveck RJ, Piantadosi CA, Bell C, Irwin D, Schroeder T. The novel combination of theophylline and bambuterol as a potential treatment of hypoxemia in humans. Can J Physiol Pharmacol 2017; 95:1009-1018. [PMID: 28467859 DOI: 10.1139/cjpp-2016-0635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hypoxemia can be life-threatening, both acutely and chronically. Because hypoxemia causes vascular dysregulation that further restricts oxygen availability to tissue, it can be pharmacologically addressed. We hypothesized that theophylline can be safely combined with the β2-adrenergic vasodilator bambuterol to improve oxygen availability in hypoxemic patients. Ergogenicity and hemodynamic effects of bambuterol and theophylline were measured in rats under hypobaric and normobaric hypoxia (12% O2). Feasibility in humans was assessed using randomized, double-blind testing of the influence of combined slow-release theophylline (300 mg) and bambuterol (20 mg) on adverse events (AEs), plasma K+, pulse, blood pressure, and drug interaction. Both drugs and their combination significantly improved hypoxic endurance in rats. In humans, common AEs were low K+ (<3.5 mmol/L; bambuterol: 12, theophylline: 4, combination: 13 episodes) and tremors (10, 0, 14 episodes). No exacerbation or serious AE occurred when drugs were combined. A drop in plasma K+ coincided with peak bambuterol plasma concentrations. Bambuterol increased heart rate by approximately 13 bpm. Drug interaction was present but small. We report promise, feasibility, and relative safety of combined theophylline and bambuterol as a treatment of hypoxemia in humans. Cardiac safety and blood K+ will be important safety endpoints when testing these drugs in hypoxemic subjects.
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Affiliation(s)
- Trond-Eirik Strand
- a Norwegian Armed Forces Medical Services, Institute of Aviation Medicine, 0313 Oslo, Norway
| | - Hasse Z Khiabani
- b Department of Pharmacology, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
| | - Alina Boico
- c Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Yulin Zhao
- c Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Karyn L Hamilton
- e Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523, USA
| | - Uwe Christians
- f iC42 Integrated Solutions in Clinical Research and Development, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jelena Klawitter
- f iC42 Integrated Solutions in Clinical Research and Development, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Robert J Noveck
- g Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Christopher Bell
- e Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523, USA
| | - David Irwin
- i Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Thies Schroeder
- i Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA.,j Department of Biochemistry and Pharmacology, University of Mainz, 55128 Mainz, Germany
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Marabotti C, Cialoni D, Pingitore A. Environment-induced pulmonary oedema in healthy individuals. THE LANCET RESPIRATORY MEDICINE 2017; 5:374-376. [PMID: 28238713 DOI: 10.1016/s2213-2600(17)30077-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 01/19/2017] [Indexed: 10/20/2022]
Affiliation(s)
- Claudio Marabotti
- National Research Council Institute of Clinical Physiology, Pisa, Italy; Unità Operativa Cardiovascolare, Unità di Terapia Intensiva Cardiologica, Ospedale della Bassa val di Cecina, Livorno 57023, Italy.
| | - Danilo Cialoni
- Divers Alert Network Europe, Roseto degli Abruzzi, Italy
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Pandey P, Lohani B, Murphy H. Pulmonary Embolism Masquerading as High Altitude Pulmonary Edema at High Altitude. High Alt Med Biol 2016; 17:353-358. [PMID: 27768392 PMCID: PMC5175419 DOI: 10.1089/ham.2016.0008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Pandey, Prativa, Benu Lohani, and Holly Murphy. Pulmonary embolism masquerading as high altitude pulmonary edema at high altitude. High Alt Med Biol. 17:353-358, 2016.-Pulmonary embolism (PE) at high altitude is a rare entity that can masquerade as or occur in conjunction with high altitude pulmonary edema (HAPE) and can complicate the diagnosis and management. When HAPE cases do not improve rapidly with descent, other diagnoses, including PE, ought to be considered. From 2013 to 2015, we identified eight cases of PE among 303 patients with initial diagnosis of HAPE. Upon further evaluation, five had deep vein thrombosis (DVT). One woman had a contraceptive ring and seven patients had no known thrombotic risks. PE can coexist with or mimic HAPE and should be considered in patients presenting with shortness of breath from high altitude regardless of thrombotic risk.
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Affiliation(s)
| | - Benu Lohani
- 2 Tribhuvan University Teaching Hospital , Kathmandu, Nepal
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Donegani E, Paal P, Küpper T, Hefti U, Basnyat B, Carceller A, Bouzat P, van der Spek R, Hillebrandt D. Drug Use and Misuse in the Mountains: A UIAA MedCom Consensus Guide for Medical Professionals. High Alt Med Biol 2016; 17:157-184. [PMID: 27583821 DOI: 10.1089/ham.2016.0080] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Donegani, Enrico, Peter Paal, Thomas Küpper, Urs Hefti, Buddha Basnyat, Anna Carceller, Pierre Bouzat, Rianne van der Spek, and David Hillebrandt. Drug use and misuse in the mountains: a UIAA MedCom consensus guide for medical professionals. High Alt Med Biol. 17:157-184, 2016.-Aims: The aim of this review is to inform mountaineers about drugs commonly used in mountains. For many years, drugs have been used to enhance performance in mountaineering. It is the UIAA (International Climbing and Mountaineering Federation-Union International des Associations d'Alpinisme) Medcom's duty to protect mountaineers from possible harm caused by uninformed drug use. The UIAA Medcom assessed relevant articles in scientific literature and peer-reviewed studies, trials, observational studies, and case series to provide information for physicians on drugs commonly used in the mountain environment. Recommendations were graded according to criteria set by the American College of Chest Physicians. RESULTS Prophylactic, therapeutic, and recreational uses of drugs relevant to mountaineering are presented with an assessment of their risks and benefits. CONCLUSIONS If using drugs not regulated by the World Anti-Doping Agency (WADA), individuals have to determine their own personal standards for enjoyment, challenge, acceptable risk, and ethics. No system of drug testing could ever, or should ever, be policed for recreational climbers. Sponsored climbers or those who climb for status need to carefully consider both the medical and ethical implications if using drugs to aid performance. In some countries (e.g., Switzerland and Germany), administrative systems for mountaineering or medication control dictate a specific stance, but for most recreational mountaineers, any rules would be unenforceable and have to be a personal decision, but should take into account the current best evidence for risk, benefit, and sporting ethics.
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Affiliation(s)
- Enrico Donegani
- 1 Department of Cardiovascular Surgery, Sabah Al-Ahmed Cardiac Center , Al-Amiri Hospital, Kuwait, State of Kuwait
| | - Peter Paal
- 2 Department of Anaesthesiology and Critical Care Medicine, Innsbruck University Hospital , Innsbruck, Austria .,3 Department of Perioperative Medicine, Barts Heart Centre, St. Bartholomew's Hospital, Barts Health NHS Trust, Queen Mary University of London, London, United Kingdom .,4 Perioperative Medicine, St. Bartholomew's Hospital , London, United Kingdom
| | - Thomas Küpper
- 5 Institute of Occupational and Social Medicine, RWTH Aachen University , Aachen, Germany
| | - Urs Hefti
- 6 Department of Orthopedic and Trauma Surgery, Swiss Sportclinic , Bern, Switzerland
| | - Buddha Basnyat
- 7 Oxford University Clinical Research Unit-Nepal , Nepal International Clinic, and Himalayan Rescue, Kathmandu, Nepal
| | - Anna Carceller
- 8 Sports Medicine School, Instituto de Medicina de Montaña y del Deporte (IMMED), Federació d'Entitats Excursionistes (FEEC), University of Barcelona , Barcelona, Spain
| | - Pierre Bouzat
- 9 Department of Anesthesiology and Critical Care, University Hospital, INSERM U1236, Neuroscience Institute, Alps University, Grenoble, France
| | - Rianne van der Spek
- 10 Department of Endocrinology and Metabolism, Academic Medical Center Amsterdam, University of Amsterdam , Amsterdam, The Netherlands
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Semen K, Yelisyeyeva O, Jarocka-Karpowicz I, Kaminskyy D, Solovey L, Skrzydlewska E, Yavorskyi O. Sildenafil reduces signs of oxidative stress in pulmonary arterial hypertension: Evaluation by fatty acid composition, level of hydroxynonenal and heart rate variability. Redox Biol 2015; 7:48-57. [PMID: 26654977 PMCID: PMC4683386 DOI: 10.1016/j.redox.2015.11.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/03/2015] [Accepted: 11/19/2015] [Indexed: 12/26/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a rare multifactorial disease with an unfavorable prognosis. Sildenafil therapy can improve functional capacity and pulmonary hemodynamics in PAH patients. Nowadays, it is increasingly recognized that the effects of sildenafil are pleiotropic and may also involve changes of the pro-/antioxidant balance, lipid peroxidation and autonomic control. In present study we aimed to assess the effects of sildenafil on the fatty acids (FAs) status, level of hydroxynonenal (HNE) and heart rate variability (HRV) in PAH patients. Patients with PAH were characterized by an increase in HNE and changes in the FAs composition with elevation of linoleic, oleic, docosahexanoic acids in phospholipids as well as reduced HRV with sympathetic predominance. Sildenafil therapy improved exercise capacity and pulmonary hemodynamics and reduced NT-proBNP level in PAH. Antioxidant and anti-inflammatory effects of sildenafil were noted from the significant lowering of HNE level and reduction of the phopholipid derived oleic, linoleic, docosahexanoic, docosapentanoic FAs. That was also associated with some improvement of HRV on account of the activation of the neurohumoral regulatory component. Incomplete recovery of the functional metabolic disorders in PAH patients may be assumed from the persistent increase in free FAs, reduced HRV with the sympathetic predominance in the spectral structure after treatment comparing to control group. The possibilities to improve PAH treatment efficacy through mild stimulation of free radical reactions and formation of hormetic reaction in the context of improved NO signaling are discussed. Sildenafil showed antioxidant and anti-inflammatory effects in pulmonary hypertension. Sildenafil reduced hydroxynonenal level and improved fatty acid profile in serum. Improvement of heart rate variability and functional capacity was noted after therapy. Mild prooxidant activity is suggested as the mechanism to improve sildenafil efficacy.
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Affiliation(s)
- Khrystyna Semen
- Department of Propedeutics of Internal Medicine #2, Danylo Halytsky Lviv National Medical University, Pekarska 69, 79010 Lviv, Ukraine.
| | - Olha Yelisyeyeva
- Department of Histology, Cytology and Embryology, Danylo Halytsky Lviv National Medical University, Pekarska 69, 79010 Lviv, Ukraine.
| | - Iwona Jarocka-Karpowicz
- Department of Analytical Chemistry, Medical University of Bialystok, Jana Kilinskego 1, 15089 Bialystok, Poland
| | - Danylo Kaminskyy
- Department of Pharmaceutical, Organic, and Bioorganic Chemistry, Danylo Halytsky Lviv National Medical University, Pekarska 69, 79010 Lviv, Ukraine
| | - Lyubomyr Solovey
- Lviv Regional Clinical Hospital, Chernigivska 7, 79010 Lviv, Ukraine
| | - Elzbieta Skrzydlewska
- Department of Analytical Chemistry, Medical University of Bialystok, Jana Kilinskego 1, 15089 Bialystok, Poland
| | - Ostap Yavorskyi
- Department of Propedeutics of Internal Medicine #2, Danylo Halytsky Lviv National Medical University, Pekarska 69, 79010 Lviv, Ukraine
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Abman SH, Hansmann G, Archer SL, Ivy DD, Adatia I, Chung WK, Hanna BD, Rosenzweig EB, Raj JU, Cornfield D, Stenmark KR, Steinhorn R, Thébaud B, Fineman JR, Kuehne T, Feinstein JA, Friedberg MK, Earing M, Barst RJ, Keller RL, Kinsella JP, Mullen M, Deterding R, Kulik T, Mallory G, Humpl T, Wessel DL. Pediatric Pulmonary Hypertension: Guidelines From the American Heart Association and American Thoracic Society. Circulation 2015; 132:2037-99. [PMID: 26534956 DOI: 10.1161/cir.0000000000000329] [Citation(s) in RCA: 676] [Impact Index Per Article: 75.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Pulmonary hypertension is associated with diverse cardiac, pulmonary, and systemic diseases in neonates, infants, and older children and contributes to significant morbidity and mortality. However, current approaches to caring for pediatric patients with pulmonary hypertension have been limited by the lack of consensus guidelines from experts in the field. In a joint effort from the American Heart Association and American Thoracic Society, a panel of experienced clinicians and clinician-scientists was assembled to review the current literature and to make recommendations on the diagnosis, evaluation, and treatment of pediatric pulmonary hypertension. This publication presents the results of extensive literature reviews, discussions, and formal scoring of recommendations for the care of children with pulmonary hypertension.
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MESH Headings
- Cardiovascular Agents/therapeutic use
- Child
- Child, Preschool
- Combined Modality Therapy
- Diagnostic Imaging/methods
- Disease Management
- Extracorporeal Membrane Oxygenation
- Genetic Counseling
- Heart Defects, Congenital/complications
- Heart Defects, Congenital/therapy
- Hernias, Diaphragmatic, Congenital/complications
- Hernias, Diaphragmatic, Congenital/therapy
- Humans
- Hypertension, Pulmonary/diagnosis
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/genetics
- Hypertension, Pulmonary/therapy
- Infant
- Infant, Newborn
- Lung/embryology
- Lung Transplantation
- Nitric Oxide/administration & dosage
- Nitric Oxide/therapeutic use
- Oxygen Inhalation Therapy
- Persistent Fetal Circulation Syndrome/diagnosis
- Persistent Fetal Circulation Syndrome/therapy
- Postoperative Complications/therapy
- Respiration, Artificial/adverse effects
- Respiration, Artificial/methods
- Ventilator-Induced Lung Injury/prevention & control
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Abstract
Acute high-altitude illness is an encompassing term for the range of pathology that the unacclimatised individual can develop at increased altitude. This includes acute mountain sickness, high-altitude cerebral oedema and high-altitude pulmonary oedema. These conditions represent an increasing clinical problem as more individuals are exposed to the hypobaric hypoxic environment of high altitude for both work and leisure. In this review of acute high-altitude illness, the epidemiology, risk factors and pathophysiology are explored, before their prevention and treatment are discussed. Appropriate ascent rate remains the most effective acute high-altitude illness prevention, with pharmacological prophylaxis indicated in selected individuals. Descent is the definitive treatment for acute high-altitude illness, with the adjuncts of oxygen and specific drug therapies.
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Affiliation(s)
- Tom Smedley
- UCL Centre for Altitude, Space and Extreme Environment Medicine, Portex Unit, Institute of Child Health, London, UK ; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Michael Pw Grocott
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, University Hospital Southampton NHS Foundation Trust, Southampton, UK ; Anaesthesia and Critical Care Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK ; NIHR Southampton Respiratory Biomedical Research Unit, Southampton, UK
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Mishra A, Mohammad G, Norboo T, Newman JH, Pasha MAQ. Lungs at high-altitude: genomic insights into hypoxic responses. J Appl Physiol (1985) 2015; 119:1-15. [DOI: 10.1152/japplphysiol.00513.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 04/20/2015] [Indexed: 11/22/2022] Open
Abstract
Hypobaric hypoxia at high altitude (HA) results in reduced blood arterial oxygen saturation, perfusion of organs with hypoxemic blood, and direct hypoxia of lung tissues. The pulmonary complications in the cells of the pulmonary arterioles due to hypobaric hypoxia are the basis of the pathophysiological mechanisms of high-altitude pulmonary edema (HAPE). Some populations that have dwelled at HA for thousands of years have evolutionarily adapted to this environmental stress; unadapted populations may react with excessive physiological responses that impair health. Individual variations in response to hypoxia and the mechanisms of HA adaptation provide insight into physiological responses. Adaptive and maladaptive responses include alterations in pathways such as oxygen sensing, hypoxia signaling, K+- and Ca2+-gated channels, redox balance, and the renin-angiotensin-aldosterone system. Physiological imbalances are linked with genetic susceptibilities, and nonhomeostatic responses in gene regulation that occur by small RNAs, histone modification, and DNA methylation predispose susceptible humans to these HA illnesses. Elucidation of the interaction of these factors will lead to a more comprehensive understanding of HA adaptations and maladaptations and will lead to new therapeutics for HA disorders related to hypoxic lungs.
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Affiliation(s)
- Aastha Mishra
- Department of Genomics and Molecular Medicine, Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Department of Biotechnology, University of Pune, Pune, India
| | - Ghulam Mohammad
- Department of Medicine, SNM Hospital, Leh, Ladakh, J&K, India
| | - Tsering Norboo
- Ladakh Institute of Prevention, Leh, Ladakh, J&K, India; and
| | - John H. Newman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - M. A. Qadar Pasha
- Department of Genomics and Molecular Medicine, Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
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Leichtfried V, Basic D, Burtscher M, Gothe RM, Siebert U, Schobersberger W. Diagnosis and prediction of the occurrence of acute mountain sickness measuring oxygen saturation--independent of absolute altitude? Sleep Breath 2015; 20:435-42. [PMID: 26032284 DOI: 10.1007/s11325-015-1195-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 04/29/2015] [Accepted: 05/03/2015] [Indexed: 11/29/2022]
Abstract
PURPOSE Commercialization of trekking tourism enables untrained persons to participate in trekking tours. Because hypoxia is one of the main purported triggers for acute mountain sickness (AMS), pulse oximetry, which measures arterial oxygen saturation (SPO2), is discussed to be a possible and useful tool for the diagnosis of AMS. The purpose of this study was to evaluate possible associations between SPO2 values and the occurrence of AMS. METHODS In 204 trekkers, SPO2 values (pulse oximetry) were measured and the Lake Louise Self-assessment Score (LLS) was administered over the first 7 days of their trekking tours. RESULTS During treks at altitudes of 2500-5500 m in Nepal, India, Africa, and South America, 100 participants suffered from mild AMS, 3 participants suffered from severe AMS, and 9 participants reported both mild and severe AMS. The lowest mean SPO2 was 85.5 (95 % confidence interval (CI), 83.9-86.1 %) on day 5. SPO2 and LLS exhibited a weak to moderate negative correlation for all days of the study (ρ ranging from -0.142 to -0.370). Calculation of time-shifted associations of 24 and 48 h resulted in the disappearance of most associations. Susceptibility to headaches (odds ratio (OR) 2.9-7.2) and a history of AMS (OR 2.2-3.1) were determined to be potential risk factors for the development of AMS. CONCLUSION Since there is no strong altitude-independent association between AMS and SPO2 during the first week of high-altitude adaptation, the implementation of pulse oximetry during trekking in order to detect and predict AMS remains questionable.
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Affiliation(s)
- Veronika Leichtfried
- Institute for Sports Medicine, Alpine Medicine and Health Tourism, UMIT-University for Health Sciences, Medical Informatics and Technology and TILAK Innsbruck, Eduard Wallnöfer Zentrum 1, 6060, Hall in Tirol, Austria.
| | - Daniel Basic
- Department of Internal Medicine III, University Hospital Innsbruck, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Martin Burtscher
- Department of Sport Science, Medical Section, University of Innsbruck, 6020, Innsbruck, Austria
| | - Raffaella Matteucci Gothe
- Institute of Public Health, Medical Decision Making and HTA, UMIT-University for Health Sciences, Medical Informatics and Technology, 6060, Hall in Tirol, Austria
| | - Uwe Siebert
- Institute of Public Health, Medical Decision Making and HTA, UMIT-University for Health Sciences, Medical Informatics and Technology, 6060, Hall in Tirol, Austria
| | - Wolfgang Schobersberger
- Institute for Sports Medicine, Alpine Medicine and Health Tourism, UMIT-University for Health Sciences, Medical Informatics and Technology and TILAK Innsbruck, Eduard Wallnöfer Zentrum 1, 6060, Hall in Tirol, Austria
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Ryan J, Dasgupta A, Huston J, Chen KH, Archer SL. Mitochondrial dynamics in pulmonary arterial hypertension. J Mol Med (Berl) 2015; 93:229-42. [PMID: 25672499 DOI: 10.1007/s00109-015-1263-5] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/27/2015] [Accepted: 02/02/2015] [Indexed: 12/31/2022]
Abstract
Pulmonary arterial hypertension (PAH) is an idiopathic cardiopulmonary disease characterized by obstruction of small pulmonary arteries. Vascular obstruction is the consequence of excessive proliferation and apoptosis resistance of vascular cells, as well as inflammation, thrombosis, and vasoconstriction. Vascular obstruction increases the afterload faced by the right ventricle (RV), leading to RV failure. The proliferative, obstructive vasculopathy of PAH shares several mitochondrial abnormalities with cancer, notably a shift to aerobic glycolysis and mitochondrial fragmentation. Mitochondria in the pulmonary artery smooth muscle cell (PASMC) normally serve as oxygen sensors. In PAH, acquired mitochondrial abnormalities, including epigenetic silencing of superoxide dismutase (SOD2), disrupt oxygen sensing creating a pseudo-hypoxic environment characterized by normoxic activation of hypoxia-inducible factor-1α (HIF-1α). The resulting metabolic shift to aerobic glycolysis (the Warburg phenomenon) reflects inhibition of pyruvate dehydrogenase by pyruvate dehydrogenase kinases. In addition, altered mitochondrial dynamics result in mitochondrial fragmentation. The molecular basis of this structural change includes upregulation and activation of fission mediators, notably dynamin-related protein 1 (DRP-1), and downregulation of fusion mediators, especially mitofusin-2 (MFN2). These pathogenic mitochondrial abnormalities offer new therapeutic targets. Inhibition of mitotic fission or enhancement of fusion in PAH PASMC slows cell proliferation, causes cell cycle arrest, and induces apoptosis. DRP-1 inhibition or MFN2 gene therapy can regress PAH in experimental models of PAH. This review focuses on the etiology of mitochondrial fragmentation in PAH and explores the therapeutic implications of mitochondrial dynamics in the pulmonary vasculature and RV.
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Affiliation(s)
- John Ryan
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah, Salt Lake City, UT, USA
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Olschewski A, Papp R, Nagaraj C, Olschewski H. Ion channels and transporters as therapeutic targets in the pulmonary circulation. Pharmacol Ther 2014; 144:349-68. [PMID: 25108211 DOI: 10.1016/j.pharmthera.2014.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 07/22/2014] [Indexed: 10/24/2022]
Abstract
Pulmonary circulation is a low pressure, low resistance, high flow system. The low resting vascular tone is maintained by the concerted action of ion channels, exchangers and pumps. Under physiological as well as pathophysiological conditions, they are targets of locally secreted or circulating vasodilators and/or vasoconstrictors, leading to changes in expression or to posttranslational modifications. Both structural changes in the pulmonary arteries and a sustained increase in pulmonary vascular tone result in pulmonary vascular remodeling contributing to morbidity and mortality in pediatric and adult patients. There is increasing evidence demonstrating the pivotal role of ion channels such as K(+) and Cl(-) or transient receptor potential channels in different cell types which are thought to play a key role in vasoconstrictive remodeling. This review focuses on ion channels, exchangers and pumps in the pulmonary circulation and summarizes their putative pathophysiological as well as therapeutic role in pulmonary vascular remodeling. A better understanding of the mechanisms of their actions may allow for the development of new options for attenuating acute and chronic pulmonary vasoconstriction and remodeling treating the devastating disease pulmonary hypertension.
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Affiliation(s)
- Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Experimental Anesthesiology, Department of Anesthesia and Intensive Care Medicine, Medical University of Graz, Austria.
| | - Rita Papp
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Horst Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Austria
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Radiloff D, Zhao Y, Boico A, Blueschke G, Palmer G, Fontanella A, Dewhirst M, Piantadosi CA, Noveck R, Irwin D, Hamilton K, Klitzman B, Schroeder T. Anti-hypotensive treatment and endothelin blockade synergistically antagonize exercise fatigue in rats under simulated high altitude. PLoS One 2014; 9:e99309. [PMID: 24960187 PMCID: PMC4068990 DOI: 10.1371/journal.pone.0099309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 05/12/2014] [Indexed: 02/04/2023] Open
Abstract
Rapid ascent to high altitude causes illness and fatigue, and there is a demand for effective acute treatments to alleviate such effects. We hypothesized that increased oxygen delivery to the tissue using a combination of a hypertensive agent and an endothelin receptor A antagonist drugs would limit exercise-induced fatigue at simulated high altitude. Our data showed that the combination of 0.1 mg/kg ambrisentan with either 20 mg/kg ephedrine or 10 mg/kg methylphenidate significantly improved exercise duration in rats at simulated altitude of 4,267 m, whereas the individual compounds did not. In normoxic, anesthetized rats, ephedrine alone and in combination with ambrisentan increased heart rate, peripheral blood flow, carotid and pulmonary arterial pressures, breathing rate, and vastus lateralis muscle oxygenation, but under inspired hypoxia, only the combination treatment significantly enhanced muscle oxygenation. Our results suggest that sympathomimetic agents combined with endothelin-A receptor blockers offset altitude-induced fatigue in rats by synergistically increasing the delivery rate of oxygen to hypoxic muscle by concomitantly augmenting perfusion pressure and improving capillary conductance in the skeletal muscle. Our findings might therefore serve as a basis to develop an effective treatment to prevent high-altitude illness and fatigue in humans.
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Affiliation(s)
- Daniel Radiloff
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Yulin Zhao
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Alina Boico
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Gert Blueschke
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Gregory Palmer
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Andrew Fontanella
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Mark Dewhirst
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Claude A. Piantadosi
- Department of Medicine-Pulmonary, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Robert Noveck
- Department of Medicine-Clinical Pharmacology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - David Irwin
- Department of Cardiology, University of Colorado Denver, Aurora, Colorado, United States of America
| | - Karyn Hamilton
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado, United States of America
| | - Bruce Klitzman
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Thies Schroeder
- Department of Physical Chemistry, University of Mainz, Mainz, Germany
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Tang E, Chen Y, Luo Y. Dexamethasone for the prevention of acute mountain sickness: Systematic review and meta-analysis. Int J Cardiol 2014; 173:133-8. [DOI: 10.1016/j.ijcard.2014.03.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 03/01/2014] [Accepted: 03/09/2014] [Indexed: 01/28/2023]
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Abstract
Many sports incorporate training at altitude as a key component of their athlete training plan. Furthermore, many sports are required to compete at high altitude venues. Exercise at high altitude provides unique challenges to the athlete and to the sport medicine clinician working with these athletes. These challenges include altitude illness, alterations in training intensity and performance, nutritional and hydration difficulties, and challenges related to the austerity of the environment. Furthermore, many of the strategies that are typically utilized by visitors to altitude may have implications from an anti-doping point of view.This position statement was commissioned and approved by the Canadian Academy of Sport and Exercise Medicine. The purpose of this statement was to provide an evidence-based, best practices summary to assist clinicians with the preparation and management of athletes and individuals travelling to altitude for both competition and training.
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Goldfarb-Rumyantzev AS, Alper SL. Short-term responses of the kidney to high altitude in mountain climbers. Nephrol Dial Transplant 2014; 29:497-506. [PMID: 23525530 PMCID: PMC3938295 DOI: 10.1093/ndt/gft051] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 01/24/2013] [Indexed: 01/07/2023] Open
Abstract
In high-altitude climbers, the kidneys play a crucial role in acclimatization and in mountain sickness syndromes [acute mountain sickness (AMS), high-altitude cerebral edema, high-altitude pulmonary edema] through their roles in regulating body fluids, electrolyte and acid-base homeostasis. Here, we discuss renal responses to several high-altitude-related stresses, including changes in systemic volume status, renal plasma flow and clearance, and altered acid-base and electrolyte status. Volume regulation is considered central both to high-altitude adaptation and to maladaptive development of mountain sickness. The rapid and powerful diuretic response to the hypobaric hypoxic stimulus of altitude integrates decreased circulating concentrations of antidiuretic hormone, renin and aldosterone, increased levels of natriuretic hormones, plasma and urinary epinephrine, norepinephrine, endothelin and urinary adrenomedullin, with increased insensible fluid losses and reduced fluid intake. The ventilatory and hormonal responses to hypoxia may predict susceptibility to AMS, also likely influenced by multiple genetic factors. The timing of altitude increases and adaptation also modifies the body's physiologic responses to altitude. While hypovolemia develops as part of the diuretic response to altitude, coincident vascular leak and extravascular fluid accumulation lead to syndromes of high-altitude sickness. Pharmacological interventions, such as diuretics, calcium blockers, steroids, phosphodiesterase inhibitors and β-agonists, may potentially be helpful in preventing or attenuating these syndromes.
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Affiliation(s)
- Alexander S. Goldfarb-Rumyantzev
- Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
- Transplant Institute, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Seth L. Alper
- Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
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Abstract
BACKGROUND Human activity in wilderness areas has increased globally in recent decades, leading to increased risk of injury and illness. Wilderness medicine has developed in response to both need and interest. METHODS The field of wilderness medicine encompasses many areas of interest. Some focus on special circumstances (such as avalanches) while others have a broader scope (such as trauma care). Several core areas of key interest within wilderness medicine are discussed in this study. RESULTS Wilderness medicine is characterized by remote and improvised care of patients with routine or exotic illnesses or trauma, limited resources and manpower, and delayed evacuation to definitive care. Wilderness medicine is developing rapidly and draws from the breadth of medical and surgical subspecialties as well as the technical fields of mountaineering, climbing, and diving. Research, epidemiology, and evidence-based guidelines are evolving. A hallmark of this field is injury prevention and risk mitigation. The range of topics encompasses high-altitude cerebral edema, decompression sickness, snake envenomation, lightning injury, extremity trauma, and gastroenteritis. Several professional societies, academic fellowships, and training organizations offer education and resources for laypeople and health care professionals. CONCLUSIONS THE FUTURE OF WILDERNESS MEDICINE IS UNFOLDING ON MULTIPLE FRONTS: education, research, training, technology, communications, and environment. Although wilderness medicine research is technically difficult to perform, it is essential to deepening our understanding of the contribution of specific techniques in achieving improvements in clinical outcomes.
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Affiliation(s)
- Douglas G. Sward
- Department of Emergency Medicine, University of Maryland School of Medicine, Hyperbaric Medicine, Shock Trauma Center, Baltimore, Maryland, USA
| | - Brad L. Bennett
- Military & Emergency Medicine Department, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
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She J, Bi J, Tong L, Song Y, Bai C. New insights of aquaporin 5 in the pathogenesis of high altitude pulmonary edema. Diagn Pathol 2013; 8:193. [PMID: 24274330 PMCID: PMC3937216 DOI: 10.1186/1746-1596-8-193] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 10/26/2013] [Indexed: 11/28/2022] Open
Abstract
Background High altitude pulmonary edema (HAPE) affects individuals and is characterized by alveolar flooding with protein-rich edema as a consequence of blood-gas barrier disruption. In this study, we hypothesized that aquaporin 5 (AQP5) which is one kind of water channels may play a role in preservation of alveolar epithelial barrier integrity in high altitude pulmonary edema (HAPE). Methods Therefore, we established a model in Wildtype mice and AQP5 −/− mice were assingned to normoxic rest (NR), hypoxic rest (HR) and hypoxic exercise (HE) group. Mice were produced by training to walk at treadmill for exercising and chamber pressure was reduced to simulate climbing an altitude of 5000 m for 48 hours. Studies using BAL in HAPE mice to demonstrated that edema is caused leakage of albumin proteins and red cells across the alveolarcapillary barrier in the absence of any evidence of inflammation. Results In this study, the Lung wet/dry weight ratio and broncholalveolar lavage protein concentrations were slightly increased in HE AQP5 −/− mice compared to wildtype mice. And histologic evidence of hemorrhagic pulmonary edema was distinctly shown in HE group. The lung Evan’s blue permeability of HE group was showed slightly increased compare to the wildtype groups, and HR group was showed a medium situation from normal to HAPE development compared with NR and HE group. Conclusions Deletion of AQP5 slightly increased lung edema and lung injury compared to wildtype mice during HAPE development, which suggested that the AQP5 plays an important role in HAPE formation induced by high altitude simulation.
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Affiliation(s)
| | | | | | | | - Chunxue Bai
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, NO,180 Fenglin Road, Shanghai 200032, China.
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Shen G, Wu X, Tang C, Yan Y, Liu J, Guo W, Jing D, Lei T, Tian Y, Xie K, Luo E, Zhang J. An oxygen enrichment device for lowlanders ascending to high altitude. Biomed Eng Online 2013; 12:100. [PMID: 24103365 PMCID: PMC4124732 DOI: 10.1186/1475-925x-12-100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 09/24/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND When ascending to the high altitude, people living in low altitude areas will suffer from acute mountain sickness. The aim of this study is to test the hypothesis that whether an oxygen concentration membrane can be made and used to construct a new portable oxygen enrichment device for individuals in acute exposure to the high altitude. METHODS The membrane was fabricated using vinylsiloxane rubber, polyphenylene oxide hydrogen silicone polymers, chloroplatinic acid and isopropyl alcohol. The membrane was assembled in a frame and the performance was tested in terms of concentration of oxygen, flow rate of oxygen enriched air, pressure ratio across the membrane and ambient temperature. Furthermore, the oxygen concentration device was constructed using the membrane, a DC fan, vacuum pump and gas buffer. A nonrandomized preliminary field test was conducted, in which eight healthy male subjects were flown to Tibet (Lhasa, 3,700 m). First, subjects wore the oxygen enrichment device and performed an incremental exercise on cycle ergometer. The test included heart rate (HR), saturation of peripheral oxygen (SpO2) and physical work capacity (PWC). Then, after a rest period of 4 hours, the experimental protocol was repeated without oxygen enrichment device. RESULTS The testing showed that the membrane could increase the oxygen concentration by up to 30%. Simulation test indicated that although the performance of the oxygen enrichment device decreased with altitudes, the oxygen concentration could still maintain 28% with flow rate of enriched air 110 cm3/s at 5000 m. The field test showed that higher SpO2, lower HR, and better PWC (measured by the PWC-170) were observed from all the subjects using oxygen enrichment device compared with non-using (P < 0.01). CONCLUSIONS We concluded that the new portable oxygen enrichment device would be effective in improving exercise performance when ascending to the high altitude.
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Affiliation(s)
- Guanghao Shen
- School of Biomedical Engineering, Fourth Military Medical University, Xi'an, Shaanxi 710032, People's Republic of China.
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Lisk C, McCord J, Bose S, Sullivan T, Loomis Z, Nozik-Grayck E, Schroeder T, Hamilton K, Irwin DC. Nrf2 activation: a potential strategy for the prevention of acute mountain sickness. Free Radic Biol Med 2013; 63:264-73. [PMID: 23722164 PMCID: PMC4130652 DOI: 10.1016/j.freeradbiomed.2013.05.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 04/09/2013] [Accepted: 05/16/2013] [Indexed: 02/08/2023]
Abstract
Reactive oxygen species (ROS) formed during acute high altitude exposure contribute to cerebral vascular leak and development of acute mountain sickness (AMS). Nuclear factor (erythroid-derived 2)-related factor 2 (Nrf2) is a transcription factor that regulates expression of greater than 90% of antioxidant genes, but prophylactic treatment with Nrf2 activators has not yet been tested as an AMS therapy. We hypothesized that prophylactic activation of the antioxidant genome with Nrf2 activators would attenuate high-altitude-induced ROS formation and cerebral vascular leak and that some drugs currently used to treat AMS symptoms have an additional trait of Nrf2 activation. Drugs commonly used to treat AMS were screened with a luciferase reporter cell system for their effectiveness to activate Nrf2, as well as being tested for their ability to decrease high altitude cerebral vascular leak in vivo. Compounds that showed favorable results for Nrf2 activation from our screen and attenuated high altitude cerebral vascular leak in vivo were further tested in brain microvascular endothelial cells (BMECs) to determine if they attenuated hypoxia-induced ROS production and monolayer permeability. Of nine drugs tested, with the exception of dexamethasone, only drugs that showed the ability to activate Nrf2 (Protandim, methazolamide, nifedipine, amlodipine, ambrisentan, and sitaxentan) decreased high-altitude-induced cerebral vascular leak in vivo. In vitro, Nrf2 activation in BMECs before 24h hypoxia exposure attenuated hypoxic-induced hydrogen peroxide production and permeability. Prophylactic Nrf2 activation is effective at reducing brain vascular leak from acute high altitude exposures. Compared to acetazolamide, methazolamide may offer better protection against AMS. Nifedipine, in addition to its known vasodilatory activities in the lung and protection against high altitude pulmonary edema, may provide protection against brain vascular leak as well.
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Affiliation(s)
- Christina Lisk
- Cardiovascular Pulmonary Research Group, Division of Cardiology, School of Medicine, University Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Joe McCord
- Pulmonary Division, University of Colorado Anschutz Medial Campus, Aurora, Colorado
| | - Swapan Bose
- Pulmonary Division, University of Colorado Anschutz Medial Campus, Aurora, Colorado
| | - Tim Sullivan
- Pulmonary Division, University of Colorado Anschutz Medial Campus, Aurora, Colorado
| | - Zoe Loomis
- Cardiovascular Pulmonary Research Group, Division of Cardiology, School of Medicine, University Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Eva Nozik-Grayck
- Cardiovascular Pulmonary Research Group, Pediatrics, School of Medicine, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Thies Schroeder
- Radiation, Oncology, Duke University, Durham, North Carolina
| | - Karyn Hamilton
- Exercise and Sports Science, Colorado State University, Fort Collins, Colorado
| | - David C. Irwin
- Cardiovascular Pulmonary Research Group, Division of Cardiology, School of Medicine, University Colorado Denver Anschutz Medical Campus, Aurora, Colorado
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Abstract
Altitude physiology began with Paul Bert in 1878. Chronic mountain sickness (CMS) was defined by Carlos Monge in the 1940s in the Peruvian Andes as consisting of excess polycythemia. Hurtado et al performed studies in the Peruvian Andes in the 1950s to 1960s which defined acclimatization in healthy altitude natives, including polycythemia, moderate pulmonary hypertension, and low systemic blood pressure (BP). Electrocardiographic changes of right ventricular hypertrophy (RVH) were noted. Acclimatization of newcomers to altitude involves hyperventilation stimulated by hypoxia and is usually benign. Acute mountain sickness (AMS) in travelers to altitude is characterized by hypoxia-induced anorexia, dyspnea, headache, insomnia, and nausea. The extremes of AMS are high-altitude cerebral edema and high-altitude pulmonary edema. The susceptible high-altitude resident can lose their tolerance to altitude and develop CMS, also referred to as Monge disease. The CMS includes extreme polycythemia, severe RVH, excess pulmonary hypertension, low systemic BP, arterial oxygen desaturation, and hypoventilation.
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Affiliation(s)
- Thomas F Whayne
- Division of Cardiovascular Medicine, Gill Heart Institute, University of Kentucky, Lexington, KY, USA
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46
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Scherrer U, Allemann Y, Rexhaj E, Rimoldi SF, Sartori C. Mechanisms and Drug Therapy of Pulmonary Hypertension at High Altitude. High Alt Med Biol 2013; 14:126-33. [DOI: 10.1089/ham.2013.1006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Urs Scherrer
- Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland
- Facultad de Ciencias, Departamento de Biología, Universidad de Tarapacá, Arica, Chile
| | - Yves Allemann
- Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland
| | - Emrush Rexhaj
- Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland
| | - Stefano F. Rimoldi
- Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland
| | - Claudio Sartori
- Department of Internal Medicine, CHUV, Lausanne, Switzerland
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Aeberli I, Erb A, Spliethoff K, Meier D, Götze O, Frühauf H, Fox M, Finlayson GS, Gassmann M, Berneis K, Maggiorini M, Langhans W, Lutz TA. Disturbed eating at high altitude: influence of food preferences, acute mountain sickness and satiation hormones. Eur J Nutr 2012; 52:625-35. [DOI: 10.1007/s00394-012-0366-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 04/24/2012] [Indexed: 12/21/2022]
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48
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Martí-Carvajal AJ, Simancas-Racines D, Hidalgo R. Interventions for treating high altitude illness. Hippokratia 2012. [DOI: 10.1002/14651858.cd009567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Arturo J Martí-Carvajal
- Universidad Tecnológica Equinoccial; Facultad de Ciencias de la Salud Eugenio Espejo; Quito Ecuador
| | - Daniel Simancas-Racines
- Universidad Tecnológica Equinoccial; Facultad de Ciencias de la Salud Eugenio Espejo; Quito Ecuador
| | - Ricardo Hidalgo
- Universidad Tecnológica Equinoccial; Facultad de Ciencias de la Salud Eugenio Espejo; Quito Ecuador
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49
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Miura G, Kato K, Shimizu T, Shiga D, Shirasawa T. Heme oxygenase-1 (HO-1) is constitutively up-regulated in top alpinists. Biochem Biophys Res Commun 2012; 417:104-8. [PMID: 22138245 DOI: 10.1016/j.bbrc.2011.11.064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 11/14/2011] [Indexed: 11/16/2022]
Abstract
Alpinists who challenge Mt. Everest need adaptation to hypoxia before the attack of Mt. Everest. Although this adaptation is important for the success of climbing Mt. Everest, the molecular mechanism on the adaptation to hypoxia is not well understood. In order to clarify this mechanism, we investigated hypoxia-induced gene expressions specific for top alpinists using microarray analyses. We report here that heme oxygenase-1 (HO-1) is significantly higher in the blood of top alpinist compared with non-alpinists. Although HO-1 expression of non-alpinists is also up-regulated in response to hypoxia, HO-1 level of the top alpinists are constitutively higher than that of non-alpinists. Serial examinations of HO-1 in one top alpinist revealed that the higher expression of HO-1 is maintained in high-level several months after the attack of top mountains. Taken together with the biochemical function of HO-1 that catalyzes heme into CO and bilirubin, HO-1 expression may improve the circulation and compensate with oxidative tissue damages induced by hypoxia. These data also suggest that peripheral blood has the memory on hypoxia independent of antigens by maintaining the high-level of HO-1 expression in top alpinists, which merits the rapid adaptation to hypoxia for 8000m climbing.
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Affiliation(s)
- Gota Miura
- Department of Aging Control Medicine, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, Japan
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50
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Latshang TD, Bloch KE. How to Treat Patients with Obstructive Sleep Apnea Syndrome during an Altitude Sojourn. High Alt Med Biol 2011; 12:303-7. [DOI: 10.1089/ham.2011.1055] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Tsogyal D. Latshang
- Sleep Disorders Center, Pulmonary Division, University Hospital of Zurich and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Konrad E. Bloch
- Sleep Disorders Center, Pulmonary Division, University Hospital of Zurich and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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