High altitude medicine & biology最新文献

{"title":"Physiopathology of High-Altitude Pulmonary Edema.","authors":"Giuseppe Miserocchi","doi":"10.1089/ham.2024.0037","DOIUrl":"10.1089/ham.2024.0037","url":null,"abstract":"<p><p>Miserocchi, Giuseppe. Physiopathology of high-altitude pulmonary edema. <i>High Alt Med Biol.</i> 26:1-12, 2025.-The air-blood barrier is well designed to accomplish the matching of gas diffusion with blood flow. This function is achieved by maintaining its thickness at ∼0.5 µm, a feature implying to keep extravascular lung water to the minimum. Exposure to hypobaric hypoxia, especially when associated with exercise, is a condition potentially leading to the development of the so-called high-altitude pulmonary edema (HAPE). This article presents a view of the physiopathology of HAPE by merging available data in humans exposed to high altitude with data from animal experimental approaches. A model is also presented to characterize HAPE nonsusceptible versus susceptible individuals based on the efficiency of alveolar-capillary oxygen uptake and estimated morphology of the air-blood barrier.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"1-12"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142345584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Naltrexone on Sleep Quality and Periodic Breathing at High Altitude.","authors":"Katharine Foster, James D Anholm, Gary Foster, Suman Thapamagar, Prajan Subedi","doi":"10.1089/ham.2024.0023","DOIUrl":"10.1089/ham.2024.0023","url":null,"abstract":"<p><p>Foster, Katharine, James D. Anholm, Gary Foster, Suman Thapamagar, and Prajan Subedi. Effects of naltrexone on sleep quality and periodic breathing at high altitude. <i>High Alt Med Biol.</i> 26:13-19, 2025. <b><i>Objective:</i></b> This study examined the effects of naltrexone on breathing and sleep at high altitude. Mu-opioid receptor (MOR) agonists have a depressive effect on respiration. Naltrexone is known to block the MOR. We hypothesized that MOR blockade with naltrexone would result in higher nocturnal oxygen saturations, fewer apneas, and improved sleep at high altitude. <b><i>Methods:</i></b> This double-blind, placebo-controlled, crossover study included nine healthy volunteers (four females, five males) aged 27.9 (4.6) (mean [standard deviation]) years. Two overnight trips spaced at least 2 weeks apart took participants from Loma Linda, CA (355 m) to the Barcroft Laboratory, CA (3,810 m) for each arm. Participants ingested either 50 mg naltrexone or matching placebo at bedtime. Sleep metrics were recorded using an ambulatory physiological sleep monitor (APSM). Subjective data were measured with the Groningen Sleep Quality Scale, Stanford Sleepiness Scale, and the 2018 Lake Louise Score (LLS) for acute mountain sickness (AMS). <b><i>Results:</i></b> Mean overnight SpO₂ was lower after taking naltrexone, 81% (6) versus 83% (4) (mean difference 1.9% [2.1, 95% confidence interval or CI = 0.1-3.6, <i>p</i> = 0.040]). The lowest overnight SpO₂ (nadir) was lower on naltrexone 70% (6) versus 74% (4) (dif. 4.6% [4.3], CI = 1.0-8.2, <i>p</i> = 0.020). Total sleep time and total apnea-hypopnea index were unchanged. Subjective sleep quality was significantly worse on naltrexone measured via the Groningen Sleep Quality Scale (<i>p</i> = 0.033) and Stanford Sleepiness Scale (<i>p</i> = 0.038). AMS measured via LLS was significantly worse while taking naltrexone (<i>p</i> = 0.025). <b><i>Conclusion:</i></b> Contrary to our hypothesis, this study demonstrated a significant decrease in nocturnal oxygen saturation, worse sleep quality, and AMS scores. Further characterization of the MOR's effects on sleep and AMS is needed to evaluate potential exacerbating mechanisms for AMS and poor sleep quality at altitude.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"13-19"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141534275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmacokinetics of Midazolam in Plasma and Brain Tissue of Rats after Exposure to Acute and Chronic High Altitude Hypoxia.","authors":"Lu Tian, Guiqin Liu, Qin Zhao, Junjun Han, Yue Lin, Qian Wang, Qiangqiang Jia, Delong Duo, Duan Yabin, Zhu Junbo, Li Xiangyang","doi":"10.1089/ham.2024.0141","DOIUrl":"https://doi.org/10.1089/ham.2024.0141","url":null,"abstract":"<p><p>Tian, Lu, Guiqin Liu, Qin Zhao, Junjun Han, Yue Lin, Wang, Jia, Delong Duo, Duan Yabin, Zhu Junbo, and Li Xiangyang. Pharmacokinetics of midazolam in plasma and brain tissue of rats after exposure to acute and chronic high altitude hypoxia. <i>High Alt Med Biol.</i> 00:00-00, 2025. <i><b>Background:</b></i> Midazolam effectively improves sleep quality under high altitude hypoxia by reducing central nervous system excitability. <i><b>Methods:</b></i> Field modeling and sample collection were performed at an altitude of 4,300 m in a high altitude hypoxic environment with a pressure of inspired oxygen of 107 mmHg. Pharmacokinetic alterations of midazolam in high altitude hypoxic rats are determined by high performance liquid chromatography-mass spectrometry. Quantitative real-time polymerase chain reaction and Western blot were used to confirm the connection with drug metabolism and alterations in hypoxia <i>CYP3A4</i> and P-glycoprotein (<i>P-gp</i>) expression. <i><b>Results:</b></i> This study demonstrated that high altitude hypoxia increased blood-brain barrier permeability in rats, caused brain tissue damage, and altered the expression of inflammatory cytokines in the brain. In the acute high altitude group and the chronic high altitude group, the area under the curve and T_max of plasma midazolam revealed substantial increases of 88.6% and 283% and 28.6% and 85.3%, respectively. The clearance rate reduced by 47.3% and 90.0%, while the brain-blood drug concentration ratio (C_brain/C_plasma) diminished by 11.4% and 82.1%, respectively. The relative expression of <i>CYP3A1</i> mRNA in the brain tissue of high altitude rats decreased by 42.4% and 66.8%, respectively, and the protein expression was downregulated, while the relative expression of <i>P-gp</i> mRNA increased by 61.3% and 91.2%, respectively (<i>p</i> < 0.05 for all parameters), and the protein expression was upregulated. High altitude hypoxia altered <i>CYP3A1</i> and <i>P-gp</i> expression and activity, causing alterations in midazolam metabolism. <i><b>Conclusions:</b></i> This research provided a new reference for the rational use of midazolam in highland areas.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Moderate-Intensity Cyclic Normobaric Hypoxic Training on Cardiovascular Disease Risk Factors of Patients Recovered from COVID-19: The AEROBICOVID Randomized Controlled Trial.","authors":"Javier Brazo-Sayavera, Alba Camacho-Cardenosa, Talita Morais Fernandes, Jamille Guedes Malta Argolo, Ana Paula Morais Fernandes, Carlos Arterio Sorgi, Elisângela Aparecida da Silva Lizzi, Átila Alexandre Trapé","doi":"10.1089/ham.2024.0125","DOIUrl":"https://doi.org/10.1089/ham.2024.0125","url":null,"abstract":"<p><p>Brazo-Sayavera, Javier, Alba Camacho-Cardenosa, Talita Morais Fernandes, Jamille Guedes Malta Argolo, Ana Paula Morais Fernandes, Carlos Arterio Sorgi, Elisângela Aparecida da Silva Lizzi, and Átila Alexandre Trapé. Effects of moderate-intensity cyclic normobaric hypoxic training on cardiovascular disease risk factors of patients recovered from COVID-19: The AEROBICOVID randomized controlled trial. <i>High Alt Med Biol.</i> 00:00-00, 2025. <b><i>Objectives:</i></b> The aim was to analyze the effects of a training program under hypoxic conditions compared with a control and normoxia training program on cardiovascular disease risk factors in patients recovered from COVID-19. <b><i>Methods:</i></b> A total of 67 patients were randomly assigned to the control group, training and recovery with hypoxia (T_H:R_H), training in normoxia (T_N) and recovery with hypoxia (R_H), and T_N and recovery in normoxia (R_N). Anthropometric, body composition, respiratory, and cardiometabolic risk factors were analyzed before and after intervention. <b><i>Results:</i></b> All intervention groups had positive effects on various health outcomes in patients recovered from COVID-19. The reduction in waist, hip, and waist/hip ratio, glycaemia, total cholesterol, and low-density lipoprotein-cholesterol indicates improvements in cardiovascular health. The increase in the forced expiratory volume in 1 second suggests improvements in respiratory health. In addition, the decrease in cardiovascular disease risk score indicates a reduction in overall cardiovascular disease risk. <b><i>Conclusions:</i></b> The study provides evidence to support the clinical benefits of moderate-intensity intermittent hypoxic training as a part of the treatment of patients recovered from COVID-19. It may also provide evidence on the efficacy and safety of intermittent hypoxic training in different health conditions. The study was registered at the Brazilian Clinical Trials Registry (RBR-5d7hkv).</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143390606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hypobaric Hypoxia Increased Autophagy and Apoptosis in PC12 Rat Pheochromocytoma Cells More Than Normobaric Hypoxia.","authors":"Jiaojiao Yin, Yuhang Wang, Bing Li, Xiaoyan Hu, Yao Ma, Chong Zhang, Xiaoqin Ha, Linyan Wang, Yaozhu Pan","doi":"10.1089/ham.2024.0041","DOIUrl":"https://doi.org/10.1089/ham.2024.0041","url":null,"abstract":"<p><p>Jiaojiao Yin, Yuhang Wang, Bing Li, Xiaoyan Hu, Yao Ma, Chong Zhang, Xiaoqin Ha, Linyan Wang, and Yaozhu Pan. Hypobaric hypoxia increased autophagy and apoptosis in PC12 rat pheochromocytoma cells more than normobaric hypoxia. <i>High Alt Med Biol.</i> 00:00-00, 2025. <b><i>Purpose:</i></b> Currently, <i>in vitro</i> studies have focused on hypoxia injury in acute mountain sickness (AMS), but little effort has been made to assess the effects of hypobaric hypoxia. AMS is a neurological disorder, and rat pheochromocytoma (PC12) cells are a model to study neuronal survival and apoptosis. Here, we developed a novel cell culture method that mimics hypobaric hypoxia at high attitude and compared the effects of hypobaric hypoxia and normobaric hypoxia on autophagy and apoptosis of PC12 cells. <b><i>Methods:</i></b> PC12 cells were cultured under normal conditions, normobaric hypoxia, and hypobaric hypoxia. Autophagy was observed by transmission electron microscopy and immunofluorescence microscopy. The hypoxia-inducible factor1-α (HIF1-α), LC3, caspase-3, and cleaved caspase-3 expression levels were determined by Western blot. <b><i>Results:</i></b> The cell culture chamber mimicking hypobaric hypoxia at high attitude perfectly maintained the air pressure at 41.1 kPa and the oxygen density at 1% (PO₂ around 3.08 mmHg). Hypobaric hypoxic treatment of PC12 cells at 0, 4, 8, 16, 24, and 48 hours resulted in an increase in HIF1-α and LC3Ⅱ protein levels, and the ratio of HIF1-α/actin and LC3Ⅱ/actin both peaked at 16 hours (<i>p</i> < 0. 01) when the cell viability was 88.02%. There was a 1.5-fold increase in LC3Ⅱ expression, a 2-fold increase in LC3B-positive spots, and an increase in autophagosome accumulation at hypobaric hypoxia compared to PC12 cells at normobaric hypoxia for 16 hours (<i>p</i> < 0.001). Interestingly, the promotion of autophagy (coculture with rapamycin or 3-MA) in PC12 cells under normobaric hypoxia reduced cleaved caspase-3 expression (the ratio of cleaved caspase-3/caspase-3 decreased, <i>p</i> < 0.01). However, under hypobaric hypoxia, the promotion of autophagy inversely increased cleaved caspase-3 (the ratio of cleaved caspase-3/caspase-3 increased, <i>p</i> < 0.01), and the inhibition of autophagy (hydroxychloroquine [HCQ] coculture) decreased cleaved caspase-3 (the ratio of cleaved caspase-3/caspase-3 decreased, <i>p</i> < 0.01). <b><i>Conclusions:</i></b> Compared with normobaric hypoxia cells, hypobaric hypoxia cells cultured <i>in vitro</i> exhibited increased autophagy and apoptosis.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143390609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Medical Problems of Chronic Hypoxia in Highlanders Living on the Tibetan Plateau.","authors":"Ri-Li Ge","doi":"10.1089/ham.2024.0107","DOIUrl":"https://doi.org/10.1089/ham.2024.0107","url":null,"abstract":"<p><p>Ri-Li Ge. Medical problems of chronic hypoxia in highlanders living on the tibetan plateau. <i>High Alt Med Biol.</i> 00:00-00, 2024.-Health issues at high altitudes arise due to the lower atmospheric pressure and subsequent reduction in the partial pressure of oxygen in ambient air. While much research has been published on health problems of lowlanders who move to high altitudes, less is known about the medical challenges faced by long-term and permanent high-altitude residents, especially in the Qinghai-Tibetan plateau. In this review, we briefly summarized the chronic hypoxia-related health issues in highlanders, focusing on the specific population of the Qinghai-Tibetan plateau. It deals with important health problems for highlanders, including the main disease categories, from chronic mountain sicknesses and pulmonary hypertension (PH) to kidney, neurocognitive impairments, perinatal problems, and congenital heart defect. However, the most hallmark of disorders is excessive erythrocytosis associated with specific symptoms and signs, and high-altitude heart disease is characterized by excessive PH, right ventricular hypertrophy, and right heart failure. We also provide information on potential treatment strategies, including some traditional Tibetan medical practices and also a combination of Western medicine and traditional Chinese medicine to prevent and treat these conditions effectively. This mini-review is heavily based on a couple of decades of research carried out by Chinese high-altitude medical research groups at the Qinghai-Tibetan Plateau. We believe that this review will provide valuable perspective to researchers whose study interest and base lie in high altitude.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143004506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical Conundrum: Climbing at the Extremes of High Elevation with Nonischemic Cardiomyopathy.","authors":"William Cornwell, Aaron L Baggish, Christoph Dehnert, Benjamin D Levine, Andrew M Luks","doi":"10.1089/ham.2024.0143","DOIUrl":"https://doi.org/10.1089/ham.2024.0143","url":null,"abstract":"<p><p>Cornwell, William, Aaron L Baggish, Christoph Dehnert, Benjamin D Levine, and Andrew M Luks. Clinical Conundrum: Climbing at the Extremes of High Elevation with Nonischemic Cardiomyopathy. <i>High Alt Med Biol.</i> 00:00-00, 2024.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142947815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex-Specific Difference in Health-Related Altitude-Effects and Their Prevention by Acetazolamide. Data from a Randomized Controlled Trial.","authors":"Alina Häfliger, Aline Buergin, Laura C Mayer, Maamed Mademilov, Mona Lichtblau, Talantbek Sooronbaev, Silvia Ulrich, Konrad E Bloch, Michael Furian","doi":"10.1089/ham.2024.0011","DOIUrl":"https://doi.org/10.1089/ham.2024.0011","url":null,"abstract":"<p><p>Häfliger, Alina, Aline Buergin, Laura C. Mayer, Maamed Mademilov, Mona Lichtblau, Talantbek Sooronbaev, Silvia Ulrich, Konrad E. Bloch, and Michael Furian. Sex-specific difference in health-related altitude-effects and their prevention by acetazolamide. Data from a randomized controlled trial. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> Women are underrepresented in studies on acute mountain sickness (AMS), altitude-induced sleep-disordered breathing and preventive acetazolamide use. <b><i>Methods:</i></b> We analyzed sex-specific altitude-effects in participants of a randomized, placebo-controlled, double-blind trial in healthy lowlanders >40 years. Participants took 375 mg/day acetazolamide or placebo starting 24 hours before ascent to and while staying 2 days at 3,100 m. Main outcomes of this analysis were sex-specific incidence of AMS (Lake Louise score ≥3), nocturnal pulse oximetry (SpO₂) and apnea-hypopnea index (AHI) at 3,100 m. <b><i>Results:</i></b> With placebo, 30 of 119 (25%) women and 4 of 51 (8%) men developed AMS (<i>p</i> = 0.009 between sexes) at 3,100 m. Among women assigned to placebo, SpO₂ (mean ± SE 84 ± 0%) and AHI (16.9 ± 1.3/h) in night 1 at 3,100 m were lower compared to men (SpO₂ 86 ± 0%; AHI 28.3 ± 1.9/h), despite similar baseline values at 760 m. Mean between-sex difference in altitude-effects (women-men) in SpO₂ was -1.4% (95% CI, -2.4 to -0.3%); AHI -10.7/h (95% CI, -15.7 to -5.7/h). The impact of acetazolamide on AMS was not significant for either sex but acetazolamide improved AHI in men (difference men-women, -9.8/h [95% CI, -16.8 to -2.7/h]). <b><i>Conclusion:</i></b> This study suggests sex-specific differences in altitude-induced hypoxemia, periodic breathing, AMS incidence, and in the response to preventive acetazolamide treatment.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142947818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling High Altitude-Induced Thromboembolic Disorders: Polycythemia or Complex Mechanisms?","authors":"Nikunj Kumar Kansara, Anurag Timothy, Rijesh Unnithan, Manas Chatterjee","doi":"10.1089/ham.2023.0121","DOIUrl":"https://doi.org/10.1089/ham.2023.0121","url":null,"abstract":"<p><p>Kansara, Nikunj Kumar, Anurag Timothy, Rijesh Unnithan, and Manas Chatterjee. Unraveling high altitude-induced thromboembolic disorders: polycythemia or complex mechanisms?. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> Thromboembolic disorders (TEDs) occurring at high altitudes due to exposure to hypoxic environments pose a significant challenge for clinicians in high-altitude area. Hypobaric hypoxia often leads to acquired erythrocytosis, which is believed to increase the incidence of thrombosis. This study aims to examine the relationship between thromboembolic events and erythrocytosis. <b><i>Methodology:</i></b> A prospective study was conducted, including all the patients admitted to Siachen hospital for TEDs from January 01, 2022, to December 31, 2022. Data on height, duration of the stay, hemoglobin (Hb), and packed cell volume levels at the time of admission were recorded. <b><i>Results:</i></b> A total of 35 cases were enrolled during the study period. The average age of the patients was 29.10 years (standard deviation: 6.06). The mean deployment height was 17,300 ft, with a range of 12,000 ft-21,600 ft. The average duration of stay was 73 days, ranging from 7 to 162 days. The mean Hb level was 18 g/dl (SD: 2.64), with a range of 12.4 g/dl-22.4 g/dl. Twenty-five cases of thrombotic events (71.4%) occurred with normal Hb levels (<17.5 mg/dl), compared with 10 cases (28.6%) with Hb levels >17.5 mg/dl. <b><i>Conclusion:</i></b> Prolonged stays at high altitudes and exposure to hypobaric hypoxia are major stressors. The study suggests that it is not elevated Hb levels, but rather the body's lack of an appropriate physiological response, that contributes to the development of thromboembolic events.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142931598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acclimatized Lowlanders Exhibit a Hypocoagulable Profile after a Passive Ascent at High Altitude.","authors":"Emeric Stauffer, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, Benoit Champigneulle","doi":"10.1089/ham.2024.0128","DOIUrl":"https://doi.org/10.1089/ham.2024.0128","url":null,"abstract":"<p><p>Stauffer, Emeric, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, and Benoit Champigneulle.Acclimatized lowlanders exhibit a hypocoagulable profile after a passive ascent at high altitude. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> Discordant results have been previously reported regarding the impact of high-altitude (HA) exposure on coagulation. We aimed to investigate changes in coagulation parameters in lowlanders exposed to HA for 14 days using a combination of dynamic coagulation assays and conventional <i>in vitro</i> tests. <b><i>Material and Methods:</i></b> We assessed coagulation in 10 lowlanders using whole-blood rotational thromboelastometry (ROTEM), thrombin generation assay (TGA) on poor-platelet plasma, and conventional coagulation tests. Tests were performed at low altitude (LA, 210 m) and at the end of a 14-day sojourn at HA, including passive ascents to 3,800 m for 6 days and then to 5,100 m for 8 days. <b><i>Results:</i></b> Conventional tests revealed significant changes in coagulation factors and inhibitors after HA exposure, although these changes remained within normal ranges. ROTEM assays demonstrated a delayed clot initiation in EXTEM/FIBTEM, without any alteration in clot firmness, in HA versus LA (<i>p</i> < 0.01). TGA changes showed an increase in time to peak (<i>p</i> < 0.01), a decrease in endogenous thrombin potential (<i>p</i> < 0.05), and a decrease in thrombin peak (<i>p</i> < 0.001). <b><i>Conclusions:</i></b> We found no evidence of hypercoagulability in lowlanders after a 14-day sojourn at HA. In contrast, dynamic coagulation assays (ROTEM and TGA) revealed a hypocoagulable pattern.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142846516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}