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Alvarez-Araos P, Jiménez S, Salazar-Ardiles C, Núñez-Espinosa C, Paez V, Rodriguez-Fernandez M, Raberin A, Millet GP, Iturriaga R, Andrade DC. Baroreflex and chemoreflex interaction in high-altitude exposure: possible role on exercise performance. Front Physiol 2024; 15:1422927. [PMID: 38895516 PMCID: PMC11184637 DOI: 10.3389/fphys.2024.1422927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 05/15/2024] [Indexed: 06/21/2024] Open
Abstract
The hypoxic chemoreflex and the arterial baroreflex are implicated in the ventilatory response to exercise. It is well known that long-term exercise training increases parasympathetic and decreases sympathetic tone, both processes influenced by the arterial baroreflex and hypoxic chemoreflex function. Hypobaric hypoxia (i.e., high altitude [HA]) markedly reduces exercise capacity associated with autonomic reflexes. Indeed, a reduced exercise capacity has been found, paralleled by a baroreflex-related parasympathetic withdrawal and a pronounced chemoreflex potentiation. Additionally, it is well known that the baroreflex and chemoreflex interact, and during activation by hypoxia, the chemoreflex is predominant over the baroreflex. Thus, the baroreflex function impairment may likely facilitate the exercise deterioration through the reduction of parasympathetic tone following acute HA exposure, secondary to the chemoreflex activation. Therefore, the main goal of this review is to describe the main physiological mechanisms controlling baro- and chemoreflex function and their role in exercise capacity during HA exposure.
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Affiliation(s)
- Pablo Alvarez-Araos
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
- Departamento de Kinesiología, Facultad de Ciencias de la Salud, Universidad de Atacama, Copiapó, Chile
| | - Sergio Jiménez
- Departamento de Kinesiología, Facultad de Ciencias de la Salud, Universidad de Atacama, Copiapó, Chile
| | - Camila Salazar-Ardiles
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Cristian Núñez-Espinosa
- Escuela de Medicina de la Universidad de Magallanes, Punta Arenas, Chile
- Centro Asistencial de Docencia e Investigación (CADI-UMAG), Santiago, Chile
| | - Valeria Paez
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Maria Rodriguez-Fernandez
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Antoine Raberin
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Gregoire P. Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Rodrigo Iturriaga
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - David C. Andrade
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
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Ramchandani R, Florica IT, Zhou Z, Alemi A, Baranchuk A. Review of Athletic Guidelines for High-Altitude Training and Acclimatization. High Alt Med Biol 2024; 25:113-121. [PMID: 38207236 DOI: 10.1089/ham.2023.0042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024] Open
Abstract
Ramchandani, Rashi, Ioana Tereza Florica, Zier Zhou, Aziz Alemi, and Adrian Baranchuk. Review of athletic guidelines for high-altitude training and acclimatization. High Alt Med Biol. 00:000-000, 2024. Introduction: Exposure to high altitude results in hypobaric hypoxia with physiological acclimatization changes that are thought to influence athletic performance. This review summarizes existing literature regarding implications of high-altitude training and altitude-related guidelines from major governing bodies of sports. Methods: A nonsystematic review was performed using PubMed and OVID Medline to identify articles regarding altitude training and guidelines from international governing bodies of various sports. Sports inherently involving training or competing at high altitude were excluded. Results: Important physiological compensatory mechanisms to high-altitude environments include elevations in blood pressure, heart rate, red blood cell mass, tidal volume, and respiratory rate. These responses can have varying effects on athletic performance. Governing sport bodies have limited and differing regulations for training and competition at high altitudes with recommended acclimatization periods ranging from 3 days to 3 weeks. Discussion: Physiological changes in response to high terrestrial altitude exposure can have substantial impacts on athletic performance. Major sport governing bodies have limited regulations and recommendations regarding altitude training and competition. Existing guidelines are variable and lack substantial evidence to support recommendations. Additional studies are needed to clarify the implications of high-altitude exposure on athletic ability to optimize training and competition.
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Affiliation(s)
- Rashi Ramchandani
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Ioana Tereza Florica
- Department of Medicine, Kingston Health Science Center, Queen's University, Kingston, Ontario, Canada
| | - Zier Zhou
- Atherosclerosis, Genomics and Vascular Biology Division, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Aziz Alemi
- Department of Cardiology, Kingston Health Science Center, Queen's University, Kingston, Ontario, Canada
| | - Adrian Baranchuk
- Department of Medicine, Kingston Health Science Center, Queen's University, Kingston, Ontario, Canada
- Department of Cardiology, Kingston Health Science Center, Queen's University, Kingston, Ontario, Canada
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Feng X, Chen Y, Yan T, Lu H, Wang C, Zhao L. Effects of various living-low and training-high modes with distinct training prescriptions on sea-level performance: A network meta-analysis. PLoS One 2024; 19:e0297007. [PMID: 38635743 PMCID: PMC11025749 DOI: 10.1371/journal.pone.0297007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 12/22/2023] [Indexed: 04/20/2024] Open
Abstract
This study aimed to separately compare and rank the effect of various living-low and training-high (LLTH) modes on aerobic and anaerobic performances in athletes, focusing on training intensity, modality, and volume, through network meta-analysis. We systematically searched PubMed, Web of Science, Embase, EBSCO, and Cochrane from their inception date to June 30, 2023. Based on the hypoxic training modality and the intensity and duration of work intervals, LLTH was divided into intermittent hypoxic exposure, continuous hypoxic training, repeated sprint training in hypoxia (RSH; work interval: 5-10 s and rest interval: approximately 30 s), interval sprint training in hypoxia (ISH; work interval: 15-30 s), short-duration high-intensity interval training (s-IHT; short work interval: 1-2 min), long-duration high-intensity interval training (l-IHT; long work interval: > 5 min), and continuous and interval training under hypoxia. A meta-analysis was conducted to determine the standardized mean differences (SMDs) among the effects of various hypoxic interventions on aerobic and anaerobic performances. From 2,072 originally identified titles, 56 studies were included in the analysis. The pooled data from 53 studies showed that only l-IHT (SMDs: 0.78 [95% credible interval; CrI, 0.52-1.05]) and RSH (SMDs: 0.30 [95% CrI, 0.10-0.50]) compared with normoxic training effectively improved athletes' aerobic performance. Furthermore, the pooled data from 29 studies revealed that active intermittent hypoxic training compared with normoxic training can effectively improve anaerobic performance, with SMDs ranging from 0.97 (95% CrI, 0.12-1.81) for l-IHT to 0.32 (95% CrI, 0.05-0.59) for RSH. When adopting a program for LLTH, sufficient duration and work intensity intervals are key to achieving optimal improvements in athletes' overall performance, regardless of the potential improvement in aerobic or anaerobic performance. Nevertheless, it is essential to acknowledge that this study incorporated merely one study on the improvement of anaerobic performance by l-IHT, undermining the credibility of the results. Accordingly, more related studies are needed in the future to provide evidence-based support. It seems difficult to achieve beneficial adaptive changes in performance with intermittent passive hypoxic exposure and continuous low-intensity hypoxic training.
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Affiliation(s)
- Xinmiao Feng
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Yonghui Chen
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Teishuai Yan
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Hongyuan Lu
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Chuangang Wang
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
| | - Linin Zhao
- Sports Coaching College, Beijing Sport University, Haidian, Beijing, China
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Toktogulova N, Breidert M, Eschbach J, Kudaibergenova I, Omurzakova U, Uvaidillaeva F, Tagaeva B, Sultanalieva R, Eftekhari P. Energy Metabolism in Residents in the Low- and Moderate Altitude Regions of Central Asia with MAFLD and Type 2 Diabetes Mellitus. Horm Metab Res 2024; 56:294-299. [PMID: 38373717 DOI: 10.1055/a-2256-6358] [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] [Indexed: 02/21/2024]
Abstract
The knowledge about the features of energy metabolism in MAFLD in the population living at different climatic and geographic heights is lacking. The goal of this study is to explore the biochemical parameters of blood and erythrocyte energy consumption in patients with MAFLD with and without DM2 living in the low- and moderate-altitude regions of Central Asia. Our study was carried out on patients living in low-altitude mountains: Bishkek, altitude=750-800 m; n=67 (MAFLD with DM 2: n=24; MAFLD without DM2: n=25; control: n=18), and At-Bashy District, Naryn Region, altitude=2046-2300 m; n=58 (MAFLD with DM2: n=28; MAFLD without DM2: n=18; control: n=12). Non-alcoholic fatty liver disease was diagnosed according to history, laboratory tests, liver ultrasound, and exclusion of other liver diseases. The level of liver fibrosis was determined using the FIB-4 score. Blood adenosine 5'-triphosphate (ATP) was determined using the CellTiter-Glo method. Healthy residents living in moderate altitudes have significantly higher levels of cytosolic ATP in their blood (p+≤+0.05) than residents living in low mountains. MAFLD is characterized by an increase in the level of ATP concentration in their blood. ATP concentration decreased significantly in patients with MAFLD with DM2 living in moderate-altitude in comparison to those living in low-altitude mountains. The results suggest that chronic altitude hypoxia leads to a breakdown in adaptive mechanisms of energy metabolism of ATP in patients with MAFLD with type 2 DM.
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Affiliation(s)
- Nurgul Toktogulova
- Hospital Therapy, IK Akhunbaev Kyrgyz State Medical Academy Faculty of General Medicine, Bishkek, Kyrgyzstan
| | | | - Judith Eschbach
- Inoviem Scientific Research, Inoviem Scientific SAS, Illkirch, France
| | - Indira Kudaibergenova
- Kyrgyz State Medical Institute of Post-Graduate Training and Advanced Training named after S B Daniyarov, Bishkek, Kyrgyzstan
| | - Uulkan Omurzakova
- Hospital Therapy, IK Akhunbaev Kyrgyz State Medical Academy Faculty of General Medicine, Bishkek, Kyrgyzstan
| | - Feruzakhan Uvaidillaeva
- Hospital Therapy, IK Akhunbaev Kyrgyz State Medical Academy Faculty of General Medicine, Bishkek, Kyrgyzstan
| | - Bermet Tagaeva
- Hospital Therapy, IK Akhunbaev Kyrgyz State Medical Academy Faculty of General Medicine, Bishkek, Kyrgyzstan
| | - Roza Sultanalieva
- Therapy1, Kyrgyz-Russian Slavic University named after B N Yeltsin, Bishkek, Kyrgyzstan
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Burtscher J, Raberin A, Brocherie F, Malatesta D, Manferdelli G, Citherlet T, Krumm B, Bourdillon N, Antero J, Rasica L, Burtscher M, Millet GP. Recommendations for Women in Mountain Sports and Hypoxia Training/Conditioning. Sports Med 2024; 54:795-811. [PMID: 38082199 PMCID: PMC11052836 DOI: 10.1007/s40279-023-01970-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2023] [Indexed: 04/28/2024]
Abstract
The (patho-)physiological responses to hypoxia are highly heterogeneous between individuals. In this review, we focused on the roles of sex differences, which emerge as important factors in the regulation of the body's reaction to hypoxia. Several aspects should be considered for future research on hypoxia-related sex differences, particularly altitude training and clinical applications of hypoxia, as these will affect the selection of the optimal dose regarding safety and efficiency. There are several implications, but there are no practical recommendations if/how women should behave differently from men to optimise the benefits or minimise the risks of these hypoxia-related practices. Here, we evaluate the scarce scientific evidence of distinct (patho)physiological responses and adaptations to high altitude/hypoxia, biomechanical/anatomical differences in uphill/downhill locomotion, which is highly relevant for exercising in mountainous environments, and potentially differential effects of altitude training in women. Based on these factors, we derive sex-specific recommendations for mountain sports and intermittent hypoxia conditioning: (1) Although higher vulnerabilities of women to acute mountain sickness have not been unambiguously shown, sex-dependent physiological reactions to hypoxia may contribute to an increased acute mountain sickness vulnerability in some women. Adequate acclimatisation, slow ascent speed and/or preventive medication (e.g. acetazolamide) are solutions. (2) Targeted training of the respiratory musculature could be a valuable preparation for altitude training in women. (3) Sex hormones influence hypoxia responses and hormonal-cycle and/or menstrual-cycle phases therefore may be factors in acclimatisation to altitude and efficiency of altitude training. As many of the recommendations or observations of the present work remain partly speculative, we join previous calls for further quality research on female athletes in sports to be extended to the field of altitude and hypoxia.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Antoine Raberin
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport, Paris, France
| | - Davide Malatesta
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Giorgio Manferdelli
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Tom Citherlet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Bastien Krumm
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Nicolas Bourdillon
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Juliana Antero
- Institut de Recherche Bio-Médicale Et d'Épidémiologie du Sport (EA 7329), French Institute of Sport, Paris, France
| | - Letizia Rasica
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland.
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Weis G, Schlichtiger J, Lackermair K, Hamm W, Schüttler D, Brunner S, Strüven A. Effect of Acute Altitude Exposure on Anaerobic Threshold Assessed by a Novel Electrocardiogram-Based Method. High Alt Med Biol 2024; 25:94-99. [PMID: 38294882 DOI: 10.1089/ham.2023.0073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024] Open
Abstract
Background: Acute altitude has a relevant impact on exercise physiology and performance. Therefore, the positive impact on the performance level is utilized as a training strategy in professional as well as recreational athletes. However, ventilatory thresholds (VTs) and lactate thresholds (LTs), as established performance measures, cannot be easily assessed at high altitudes. Therefore, a noninvasive, reliable, and cost-effective method is needed to facilitate and monitor training management at high altitudes. High Alt Med Biol. 25:94-99, 2024. Methods: In a cross-sectional setting, a total of 14 healthy recreational athletes performed a graded cycling exercise test at sea level (Munich, Germany: 512 m/949 mbar) and high altitude (Zugspitze: 2,650 m/715 mbar). Anaerobic thresholds (ATs) were assessed using a novel method based on beat-to-beat repolarization instability (dT) detected by Frank-lead electrocardiogram (ECG) monitoring. The ECG-based ATs (ATdT°) were compared to routine LTs assessed according to Dickhuth and Mader. Results: After acute altitude exposure, a decrease in AT was detected using a novel ECG-based method (ATdT°: 159.80 ± 52.21 W vs. 134.66 ± 34.91 W). AtdT° levels correlated significantly with LTDickhuth and LTMader, at baseline (rDickhuth/AtdT° = 0.979; p < 0.001) (rMader/AtdT° = 0.943; p < 0.001), and at high altitude (rDickhuth/AtdT° = 0.969; p < 0.001) (rMader/AtdT° = 0.942; p < 0.001). Conclusion: Assessment of ATdT is a reliable method to detect performance alterations at altitude. This novel method may facilitate the training management of athletes at high altitudes.
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Affiliation(s)
- Georges Weis
- Department of Medicine I, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
- Centre for Sports Medicine, Sports Cardiology, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
| | - Jenny Schlichtiger
- Department of Medicine I, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
- Centre for Sports Medicine, Sports Cardiology, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
| | - Korbinian Lackermair
- Department of Medicine I, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
- Centre for Sports Medicine, Sports Cardiology, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
| | - Wolfgang Hamm
- Department of Medicine I, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
- Centre for Sports Medicine, Sports Cardiology, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
| | - Dominik Schüttler
- Department of Medicine I, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
- Centre for Sports Medicine, Sports Cardiology, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
| | - Stefan Brunner
- Department of Medicine I, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
- Centre for Sports Medicine, Sports Cardiology, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
| | - Anna Strüven
- Department of Medicine I, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
- Centre for Sports Medicine, Sports Cardiology, LMU Hospital Munich, Ludwig Maximilian University, Munich, Germany
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Zhang X, Zhang Y, Si Y, Gao N, Zhang H, Yang H. A high altitude respiration and SpO2 dataset for assessing the human response to hypoxia. Sci Data 2024; 11:248. [PMID: 38413602 PMCID: PMC10899206 DOI: 10.1038/s41597-024-03065-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 02/13/2024] [Indexed: 02/29/2024] Open
Abstract
This report presents the Harespod dataset, an open dataset for high altitude hypoxia research, which includes respiration and SpO2 data. The dataset was collected from 15 college students aged 23-31 in a hypobaric oxygen chamber, during simulated altitude changes and induced hypoxia. Real-time physiological data, such as oxygen saturation waveforms, oxygen saturation, respiratory waveforms, heart rate, and pulse rate, were obtained at 100 Hz. Approximately 12 hours of valid data were collected from all participants. Researchers can easily identify the altitude corresponding to physiological signals based on their inherent patterns. Time markers were also recorded during altitude changes to facilitate realistic annotation of physiological signals and analysis of time-difference-of-arrival between various physiological signals for the same altitude change event. In high altitude scenarios, this dataset can be used to enhance the detection of human hypoxia states, predict respiratory waveforms, and develop related hardware devices. It will serve as a valuable and standardized resource for researchers in the field of high altitude hypoxia research, enabling comprehensive analysis and comparison.
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Affiliation(s)
- Xi Zhang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, China
- Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Yu Zhang
- School of Computer Science, Northwestern Polytechnical University, Xi'an, 710129, China.
| | - Yingjun Si
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, China
- Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Nan Gao
- Department of Computer Science and Technology, Tsinghua University, Beijing, 100084, China
| | - Honghao Zhang
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Hui Yang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.
- Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, Northwestern Polytechnical University, Xi'an, 710072, China.
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Raberin A, Burtscher J, Citherlet T, Manferdelli G, Krumm B, Bourdillon N, Antero J, Rasica L, Malatesta D, Brocherie F, Burtscher M, Millet GP. Women at Altitude: Sex-Related Physiological Responses to Exercise in Hypoxia. Sports Med 2024; 54:271-287. [PMID: 37902936 PMCID: PMC10933174 DOI: 10.1007/s40279-023-01954-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2023] [Indexed: 11/01/2023]
Abstract
Sex differences in physiological responses to various stressors, including exercise, have been well documented. However, the specific impact of these differences on exposure to hypoxia, both at rest and during exercise, has remained underexplored. Many studies on the physiological responses to hypoxia have either excluded women or included only a limited number without analyzing sex-related differences. To address this gap, this comprehensive review conducted an extensive literature search to examine changes in physiological functions related to oxygen transport and consumption in hypoxic conditions. The review encompasses various aspects, including ventilatory responses, cardiovascular adjustments, hematological alterations, muscle metabolism shifts, and autonomic function modifications. Furthermore, it delves into the influence of sex hormones, which evolve throughout life, encompassing considerations related to the menstrual cycle and menopause. Among these physiological functions, the ventilatory response to exercise emerges as one of the most sex-sensitive factors that may modify reactions to hypoxia. While no significant sex-based differences were observed in cardiac hemodynamic changes during hypoxia, there is evidence of greater vascular reactivity in women, particularly at rest or when combined with exercise. Consequently, a diffusive mechanism appears to be implicated in sex-related variations in responses to hypoxia. Despite well-established sex disparities in hematological parameters, both acute and chronic hematological responses to hypoxia do not seem to differ significantly between sexes. However, it is important to note that these responses are sensitive to fluctuations in sex hormones, and further investigation is needed to elucidate the impact of the menstrual cycle and menopause on physiological responses to hypoxia.
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Affiliation(s)
- Antoine Raberin
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Johannes Burtscher
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Tom Citherlet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Giorgio Manferdelli
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Bastien Krumm
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Nicolas Bourdillon
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Juliana Antero
- Institut de Recherche Bio-Médicale Et d'Épidémiologie du Sport (EA 7329), French Institute of Sport, Paris, France
| | - Letizia Rasica
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - Davide Malatesta
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport, Paris, France
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
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Tan L, Li Y, Chen H, Lanzi G, Hu X. Sleep at high altitude: A bibliometric study and visualization analysis from 1992 to 2022. Heliyon 2024; 10:e23041. [PMID: 38163230 PMCID: PMC10755286 DOI: 10.1016/j.heliyon.2023.e23041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/20/2023] [Accepted: 11/24/2023] [Indexed: 01/03/2024] Open
Abstract
Background As an important monitoring index for adaptation to hypoxia, sleep may reflect the adaptive state of the body at high altitudes. The literature has shown a link between altitude and sleep problems, and sleep changes have become a common problem for individuals at high altitudes, negatively impacting their physical and mental health. As research on high-altitude sleep has gained attention in recent years, the publishing volume has increased worldwide, necessitating a more comprehensive understanding of this field. This manuscript evaluates the key themes and emerging trends in high-altitude sleep over the past few decades and predicts future research directions. Methods Articles related to high-altitude sleep published from 1992 to 2022 were retrieved from the Web of Science Core Collection, and the relevant literature characteristics were extracted after the screening. Then, bibliometric analyses and visualizations were performed using Microsoft Excel, CiteSpace, VOSviewer, and an online analysis platform (http://bibliometric.com). Results A total of 1151 articles were retrieved, of which 368 were included in the analysis, indicating a gradually increasing trend. The United States, Switzerland, and China have made significant contributions in this field. Bloch KE from the University of Zurich was determined to be the most productive and academically influential author in this field. The highest-yielding journal was High Altitude Medicine & Biology. Initially, altitude training was the primary research topic. Currently, research focuses on sleep disorders and sleep apnea. In the coming years, keywords such as "sleep quality," "prevalence," and "obstructive sleep apnea" will attract more attention. Conclusion Our findings will assist scholars to better understand the intellectual structure and emerging trends in this field. Future developments in high-altitude sleep research are highly anticipated, particularly in terms of sleep quality at high altitudes and its associated prevalence. This research is also crucial for the improvement and treatment of symptoms during nocturnal sleep in patients with chronic hypoxia due to cardiopulmonary diseases at high altitudes.
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Affiliation(s)
- Lixia Tan
- Innovation Center of Nursing Research and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
- Medical College, Tibet University, Lhasa, China
| | - Yong Li
- Innovation Center of Nursing Research and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
| | - Hongxiu Chen
- Innovation Center of Nursing Research and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
| | | | - Xiuying Hu
- Innovation Center of Nursing Research and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
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Ducharme JB, McKenna ZJ, Specht JW, Fennel ZJ, Berkemeier QN, Deyhle MR. Divergent mechanisms regulate TLR4 expression on peripheral blood mononuclear cells following workload-matched exercise in normoxic and hypoxic environments. J Appl Physiol (1985) 2024; 136:33-42. [PMID: 37994415 DOI: 10.1152/japplphysiol.00626.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/06/2023] [Accepted: 11/19/2023] [Indexed: 11/24/2023] Open
Abstract
Exercise in hypoxia increases immune responses compared with normoxic exercise, and while Toll-like receptor 4 (TLR4) is implicated in these responses, its regulation remains undefined. The purpose of this study was to 1) investigate TLR4 regulation during workload-matched endurance exercise in normoxic and hypoxic conditions in vivo and 2) determine the independent effects of hypoxia and muscle contractions on TLR4 expression in vitro. Eight recreationally active men cycled for 1 h at 65% of their V̇o2max in normoxia (630 mmHg) and in hypobaric hypoxia (440 mmHg). Exercise in normoxia decreased TLR4 expressed on peripheral blood mononuclear cells (PBMCs), had no effect on the expression of inhibitor of κBα (IκBα), and increased the concentration of soluble TLR4 (sTLR4) in circulation. In contrast, exercise in hypoxia decreased the expression of TLR4 and IκBα in PBMCs, and sTLR4 in circulation. Markers of physiological stress were higher during exercise in hypoxia, correlating with markers of intestinal barrier damage, circulating lipopolysaccharides (LPS), and a concurrent decrease in circulating sTLR4, suggesting heightened TLR4 activation, internalization, and degradation in response to escalating physiological strain. In vitro, both hypoxia and myotube contractions independently, and in combination, reduced TLR4 expressed on C2C12 myotubes, and these effects were dependent on hypoxia-inducible factor 1 (HIF-1). In summary, the regulation of TLR4 varies depending on the physiological stress during exercise. To our knowledge, our study provides the first evidence of exercise-induced effects on sTLR4 in vivo and highlights the essential role of HIF-1 in the reduction of TLR4 during contraction and hypoxia in vitro.NEW & NOTEWORTHY We provide the first evidence of exercise affecting soluble Toll-like receptor 4 (sTLR4), a TLR4 ligand decoy receptor. We found that the degree of exercise-induced physiological stress influences TLR4 regulation on peripheral blood mononuclear cells (PBMCs). Moderate-intensity exercise reduces PBMC TLR4 and increases circulating sTLR4. Conversely, workload-matched exercise in hypoxia induces greater physiological stress, intestinal barrier damage, circulating lipopolysaccharides, and reduces both TLR4 and sTLR4, suggesting heightened TLR4 activation, internalization, and degradation under increased strain.
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Affiliation(s)
- Jeremy B Ducharme
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Zachary J McKenna
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
- Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Jonathan W Specht
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Zachary J Fennel
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States
| | - Quint N Berkemeier
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Michael R Deyhle
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, New Mexico, United States
- Department of Cell Biology and Physiology, School of Medicine, University of New Mexico, Albuquerque, New Mexico, United States
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Kalva-Filho CA, Faria MH, Papoti M, Barbieri FA. Acute and cumulative effects of hypoxia exposure in people with Parkinson's disease: A scoping review and evidence map. Parkinsonism Relat Disord 2024; 118:105885. [PMID: 37872033 DOI: 10.1016/j.parkreldis.2023.105885] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 09/29/2023] [Accepted: 10/01/2023] [Indexed: 10/25/2023]
Abstract
Hypoxia exposure may promote neuroprotection for people with Parkinson's disease (PwPD). However, to implement hypoxia in practical settings and direct future research, it is necessary to organize the current knowledge about hypoxia responses/effects in PwPD. Thus, the present scoping review elucidates the evidence about hypoxia exposure applied to PwPD. Following the PRISMA Extension for Scoping Reviews, papers were searched in PubMed/NCBI, Web of Science, and Scopus (descriptors: Parkinson and hypoxia, mountain, or altitude). We included original articles published in English until August 12, 2023. Eight studies enrolled participants with early to moderate stages of disease. Acute responses demonstrated that PwPD exposed to normobaric hypoxia presented lower hypoxia ventilatory responses (HVR), perceptions of dyspnea, and sympathetic activations. Cumulative exposure to hypobaric hypoxia (living high; 7 days; altitude not reported) induced positive effects on motor symptoms (hypokinesia) and perceptions of PwPD (quality of life and living with illness). Normobaric hypoxia (isocapnic rebreathe, 14 days, three times/day of 5-7 min at 8-10 % of O2) improved HVR. The included studies reported no harmful effects. Although these results demonstrate the effectiveness and safety of hypoxia exposure applied to PwPD, we also discuss the methodological limitations of the selected experimental design (no randomized controlled trials), the characterization of the hypoxia doses, and the range of symptoms investigated. Thus, despite the safety of both normobaric hypoxia and hypobaric hypoxia for early to moderate levels of disease, the current literature is still incipient, limiting the use of hypoxia exposure in practical settings.
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Affiliation(s)
- Carlos A Kalva-Filho
- Human Movement Research Laboratory (MOVI-LAB), Department of Physical Education, School of Sciences, São Paulo State University (UNESP), Bauru, SP, Brazil.
| | - Murilo Henrique Faria
- Human Movement Research Laboratory (MOVI-LAB), Department of Physical Education, School of Sciences, São Paulo State University (UNESP), Bauru, SP, Brazil
| | - Marcelo Papoti
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Fabio Augusto Barbieri
- Human Movement Research Laboratory (MOVI-LAB), Department of Physical Education, School of Sciences, São Paulo State University (UNESP), Bauru, SP, Brazil
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Gupta D, Wal P, Mishra M, Wal A, Rathore S, Shanker Pandey S, Saraswat N, Saxena B. Recent Progress in the Understanding and Management of Acute Mountain Sickness: A Narrative Review. Curr Rev Clin Exp Pharmacol 2024; 19:213-224. [PMID: 37888823 DOI: 10.2174/0127724328237059230919093818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 08/14/2023] [Accepted: 08/30/2023] [Indexed: 10/28/2023]
Abstract
BACKGROUND Individuals at higher altitudes may experience a decrease in blood oxygen levels, which can result in a variety of clinical illnesses, such as high-altitude pulmonary edema, high-altitude cerebral edema, and milder but more common acute mountain sickness (AMS). OBJECTIVE This study aims to review the current state of knowledge related to motion sickness, the risk of AMS, and pharmacological and non-pharmacological treatments for AMS. METHODS Several databases, including PubMed, Bentham Science, Elsevier, Springer, and Research Gate, were used to compile the data for the article following a thorough analysis of the various research findings connected to acute mountain sickness and motion sickness, along with treatments and prevention. RESULTS This article covers the research on mountain sickness as well as every imaginable form of conventional and alternative medicine. It contains ten medicinal plants that are useful in treating mountain sickness and various other remedies. Additionally, case studies are provided. CONCLUSION Therefore, the information in the paper will help travel medicine specialists better personalize their appropriate care for patients who travel to high-altitude locations. Additionally, all available antiemetic medications, serotonin agonists, nonsteroidal anti-inflammatory drugs, and herbal treatments for motion sickness were discussed. The prevention and consequences of acute mountain sickness are also covered in this study.
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Affiliation(s)
- Divyanshi Gupta
- Department of Pharmacy, Pranveer Singh Institute of Technology (Pharmacy), Kanpur, India
| | - Pranay Wal
- Department of Pharmacy, Pranveer Singh Institute of Technology (Pharmacy), Kanpur, India
| | - Mudita Mishra
- Department of Pharmacy, Quantum School of Health Sciences, Roorkee, Uttarakhand, India
| | - Ankita Wal
- Department of Pharmacy, Pranveer Singh Institute of Technology (Pharmacy), Kanpur, India
| | | | | | - Nikita Saraswat
- Dr. D.Y Patil College of Pharmacy, Akurdi, Pune, Maharashtra, India
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Bonato G, Goodman S, Tjh L. Physiological and performance effects of live high train low altitude training for elite endurance athletes: A narrative review. Curr Res Physiol 2023; 6:100113. [PMID: 38107789 PMCID: PMC10724230 DOI: 10.1016/j.crphys.2023.100113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 11/10/2023] [Accepted: 11/21/2023] [Indexed: 12/19/2023] Open
Abstract
Altitude training has become an important training application for athletes due its potential for altering physiology and enhancing performance. This practice is commonly used by athletes, with a popular choice being the live high - train low approach. This model recommends that athletes live at high altitude (1250-3000 m), but train at low altitude or sea-level (0-1200 m). Exposure to altitude often leads to hypoxic stress and in turn stimulates changes in total haemoglobin mass, erythropoietin, and soluble transferrin receptors, which alter further underlying physiology. Through enhanced physiology, improved exercise performance may arise through enhancement of the oxygen transport system which is important for endurance events. Previous investigations into the effects of altitude training on exercise performance have been completed in a range of contexts, including running, cycling, swimming, and triathlon. Often following a LHTL altitude intervention, athletes realise improvements in maximal oxygen consumption capacity, time trial performance and peak power outputs. Although heterogeneity exists among LHTL methodologies, i.e., exposure durations and altitude ranges, we synthesised this data into kilometre hours, and found that the most common hypoxic doses used in LHTL interventions ranged from ∼578-687 km h. As this narrative review demonstrates, there are potential advantages to using altitude training to enhance physiology and improve performance for endurance athletes.
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Affiliation(s)
- G. Bonato
- Exercise and Sports Science, School of Science and Technology, The University of New England, Armidale, 2350, Australia
- College of Arts, Society and Education, James Cook University, Townsville, 4811, Australia
| | - S.P.J Goodman
- Exercise and Sports Science, School of Science and Technology, The University of New England, Armidale, 2350, Australia
| | - Lathlean Tjh
- Exercise and Sports Science, School of Science and Technology, The University of New England, Armidale, 2350, Australia
- The Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, 5000, Australia
- South Australian Health and Medical Research Institute (SAHMRI), Adelaide, 5000, Australia
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春花, 白玛康卓. [Establishment and Evaluation of a Mice Model of High-Altitude Cerebral Edema]. SICHUAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF SICHUAN UNIVERSITY. MEDICAL SCIENCE EDITION 2023; 54:1269-1275. [PMID: 38162056 PMCID: PMC10752796 DOI: 10.12182/20231160604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Indexed: 01/03/2024]
Abstract
Objective To establish an animal model of high-altitude cerebral edema (HACE), to explore the altitude and oxygen partial pressure conditions that can lead to obvious clinical manifestations of HACE, and to lay the foundation for further research of the pathogenic mechanisms and intervention strategies of HACE. Methods Male BALB/c mice of 8 weeks old were randomly assigned to Control and HACE groups. The Control group (n=10) was treated with normobaric and normoxic conditions, while the HACE groups were placed in hypobaric hypoxic (HH) chambers for the durations of 6 h, 12 h, 24 h, 48 h and 72 h, respectively, receiving treatments of simulated HH conditions at the altitudes of 4000 m (n=10 for each group receiving different durations of HH treatment), 5000 m (n=10 for each group receiving different durations of HH treatment), and 6000 m (n=10 for each group receiving different durations of HH treatment). HE staining was performed to observe the morphological changes of the brain tissue and the appropriate simulated altitude conditions were selected accordingly for the construction and evaluation of the best HACE model. The HACE model was evaluated in the following ways, the mouse brain was weighed and the cerebral edema was measured accordingly, Evans blue (EB) was injected to determine the permeability of the blood-brain barrier (BBB), and the cell apoptosis was determined by immunofluorescence staining. Results There were no deaths in the groups treated with the HH conditions of the altitudes of 4000 m and 5000 m, while the mortality in the 6000 m altitude treatment groups was 12.2%. HE staining showed no significant changes in brain morphology or structure in the group receiving HH treatment for the altitude of 4000 m. A small amount of brain cell edema was observed in the groups receiving 48 h and 72 h of HH treatment for the altitude of 5000 m. The groups receiving HH treatment for the altitude of 6000 m demonstrated the most prominent modeling effect. HE staining showed increased volume and swelling of brain cells in all the 6000 m groups, especially in the 24 h, 48 h and 72 h treatment groups. In all the 6000 m groups, cell arrangement disorder, gap enlargement, and nuclear contraction were observed. Evaluation of the modeling effect demonstrated that, in the HACE mice model constructed with the HH conditions for the altitude of 6000 m, cerebral edema and EB permeability increased after 12 h HH treatment and there was no obvious apoptosis in the modeling groups receiving different durations of treatment. Conclusion The HACE model can be established effectively by simulating conditions at the altitude of 6000 m (the atmospheric pressure being 47.19 kPa and the oxygen partial pressure being 9.73 kPa) with a HH chamber.
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Affiliation(s)
- 春花
- 西藏大学医学院 (拉萨 850000)Medical College of Tibet University, Lhasa 850000, China
| | - 白玛康卓
- 西藏大学医学院 (拉萨 850000)Medical College of Tibet University, Lhasa 850000, China
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Narang BJ, Manferdelli G, Bourdillon N, Millet GP, Debevec T. Ventilatory responses to independent and combined hypoxia, hypercapnia and hypobaria in healthy pre-term-born adults. J Physiol 2023. [PMID: 37796451 DOI: 10.1113/jp285300] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/18/2023] [Indexed: 10/06/2023] Open
Abstract
Pre-term birth is associated with physiological sequelae that persist into adulthood. In particular, modulated ventilatory responsiveness to hypoxia and hypercapnia has been observed in this population. Whether pre-term birth per se causes these effects remains unclear. Therefore, we aimed to assess pulmonary ventilation and blood gases under various environmental conditions, comparing 17 healthy prematurely born individuals (mean ± SD; gestational age, 28 ± 2 weeks; age, 21 ± 4 years; peak oxygen uptake, 48.1 ± 11.2 ml kg-1 min-1 ) with 16 well-matched adults born at term (gestational age, 40 ± 1 weeks; age, 22 ± 2 years; peak oxygen uptake, 51.2 ± 7.7 ml kg-1 min-1 ). Participants were exposed to seven combinations of hypoxia/hypobaria (equivalent to ∼3375 m) and/or hypercapnia (3% CO2 ), at rest for 6 min. Pulmonary ventilation, pulse oxygen saturation and the arterial partial pressures of O2 and CO2 were similar in pre-term and full-term individuals under all conditions. Higher ventilation in hypoxia compared to normoxia was only observed at terrestrial altitude, despite an equivalent (normobaric) hypoxic stimulus administered at sea level (0.138F i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ). Assessment of oscillations in key variables revealed that combined hypoxic hypercapnia induced greater underlying fluctuations in ventilation in pre-term individuals only. In general, higher pulse oxygen saturation fluctuations were observed with hypoxia, and lower fluctuations in end-tidal CO2 with hypercapnia, despite similar ventilatory oscillations observed between conditions. These findings suggest that healthy prematurely born adults display similar overall ventilation to their term-born counterparts under various environmental stressors, but that combined ventilatory stimuli could induce an irregular underlying ventilatory pattern. Moreover, barometric pressure may be an important factor when assessing ventilatory responsiveness to moderate hypoxic stimuli. KEY POINTS: Evidence exists for unique pulmonary and respiratory function under hypoxic conditions in adult survivors of pre-term birth. Whether pre-term birth per se causes these differences requires a comparison of conventionally healthy prematurely born adults with an appropriately matched sample of term-born individuals. According to the present data, there is no difference between healthy pre-term and well-matched term-born individuals in the magnitude of pulmonary ventilation or arterial blood gases during independent and combined hypobaria, hypoxia and hypercapnia. Terrestrial altitude (hypobaria) was necessary to induce differences in ventilation between normoxia and a hypoxic stimulus equivalent to ∼3375 m of altitude. Furthermore, peak power in pulse oxygen saturation was similar between hypobaric normoxia and normobaric hypoxia. The observed similarities between groups suggest that ventilatory regulation under various environmental stimuli is not impaired by pre-term birth per se. Instead, an integrated combination of neonatal treatment strategies and cardiorespiratory fitness/disease status might underlie previously observed chemosensitivity impairments.
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Affiliation(s)
- Benjamin J Narang
- Department of Automatics, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | | | - Nicolas Bourdillon
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Tadej Debevec
- Department of Automatics, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
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Davie A, Beavers R, Hargitaiová K, Denham J. The Emerging Role of Hypoxic Training for the Equine Athlete. Animals (Basel) 2023; 13:2799. [PMID: 37685063 PMCID: PMC10486977 DOI: 10.3390/ani13172799] [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: 07/19/2023] [Revised: 08/21/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
This paper provides a comprehensive discussion on the physiological impacts of hypoxic training, its benefits to endurance performance, and a rationale for utilizing it to improve performance in the equine athlete. All exercise-induced training adaptations are governed by genetics. Exercise prescriptions can be tailored to elicit the desired physiological adaptations. Although the application of hypoxic stimuli on its own is not ideal to promote favorable molecular responses, exercise training under hypoxic conditions provides an optimal environment for maximizing physiological adaptations to enhance endurance performance. The combination of exercise training and hypoxia increases the activity of the hypoxia-inducible factor (HIF) pathway compared to training under normoxic conditions. Hypoxia-inducible factor-1 alpha (HIF-1α) is known as a master regulator of the expression of genes since over 100 genes are responsive to HIF-1α. For instance, HIF-1-inducible genes include those critical to erythropoiesis, angiogenesis, glucose metabolism, mitochondrial biogenesis, and glucose transport, all of which are intergral in physiological adaptations for endurance performance. Further, hypoxic training could conceivably have a role in equine rehabilitation when high-impact training is contraindicated but a quality training stimulus is desired. This is achievable through purpose-built equine motorized treadmills inside commercial hypoxic chambers.
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Affiliation(s)
- Allan Davie
- Australian Equine Racing and Research Centre, Ballina, NSW 2478, Australia
| | - Rosalind Beavers
- Faculty of Health, Southern Cross University, Lismore, NSW 2480, Australia;
| | - Kristýna Hargitaiová
- Department of Clinical Sciences, Cornell University, 930 Campus Rd, Ithaca, NY 14850, USA;
| | - Joshua Denham
- School of Health and Medical Sciences, University of Southern Queensland, Toowoomba, QLD 4305, Australia;
- Centre for Health Research, Toowoomba, QLD 4350, Australia
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Li L, Lin L, Wen B, Zhao PC, Liu DS, Pang GM, Wang ZR, Tan Y, Lu C. Promising Natural Medicines for the Treatment of High-Altitude Illness. High Alt Med Biol 2023; 24:175-185. [PMID: 37504973 PMCID: PMC10516238 DOI: 10.1089/ham.2022.0139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 06/27/2023] [Indexed: 07/29/2023] Open
Abstract
Li Li, Lin Lin, Bo Wen, Peng-cheng Zhao, Da-sheng Liu, Guo-ming Pang, Zi-rong Wang, Yong Tan, and Cheng Lu. Promising natural medicines for the treatment of high-altitude illness. High Alt Med Biol. 24:175-185, 2023.-High-altitude illness (HAI) is a dangerous disease characterized by oxidative stress, inflammatory damage and hemodynamic changes in the body that can lead to severe damage to the lungs, heart, and brain. Natural medicines are widely known for their multiple active ingredients and pharmacological effects, which may be important in the treatment of HAI. In this review, we outline the specific types of HAI and the underlying pathological mechanisms and summarize the currently documented natural medicines applied in the treatment of acute mountain sickness and high-altitude cerebral edema, high-altitude pulmonary edema, chronic mountain sickness, and high-altitude pulmonary hypertension. Their sources, types, and medicinal sites are summarized, and their active ingredients, pharmacological effects, related mechanisms, and potential toxicity are discussed. In conclusion, natural medicines, as an acceptable complementary and alternative strategy with fewer side effects and more long-term application, can provide a reference for developing more natural antialtitude sickness medicines in the future and have good application prospects in HAI treatment.
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Affiliation(s)
- Li Li
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Lin Lin
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Bo Wen
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Peng-cheng Zhao
- School of Life Science, Northwestern Polytechnical University, Xi'an, China
| | - Da-sheng Liu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Guo-ming Pang
- Kaifeng Traditional Chinese Medicine Hospital, Kaifeng, China
| | - Zi-rong Wang
- Logistics Support Division, National Immigration Administration, Beijing, China
| | - Yong Tan
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Cheng Lu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
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Sharma P, Mohanty S, Ahmad Y. A study of survival strategies for improving acclimatization of lowlanders at high-altitude. Heliyon 2023; 9:e14929. [PMID: 37025911 PMCID: PMC10070159 DOI: 10.1016/j.heliyon.2023.e14929] [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: 12/26/2022] [Revised: 03/14/2023] [Accepted: 03/22/2023] [Indexed: 03/30/2023] Open
Abstract
Human Acclimatization and therapeutic approaches are the core components for conquering the physiological variations at high altitude (≥2500 m) exposure. The declined atmospheric pressure and reduced partial pressure of oxygen at high altitudes tend to decrease the temperature by several folds. Hypobaric hypoxia is a major threat to humanity at high altitudes, and its potential effects include altitude mountain sickness. On severity, it may lead to the development of conditions like high-altitude cerebral edema (HACE) or high-altitude pulmonary edema (HAPE) and cause unexpected physiological changes in the healthy population of travelers, athletes, soldiers, and low landers while sojourning at high altitude. Previous investigations have been done on long-drawn-out acclimatization strategies such as the staging method to prevent the damage caused by high-altitude hypobaric Hypoxia. Inherent Limitations of this strategy hamper the daily lifestyle and time consuming for people. It is not suitable for the rapid mobilization of people at high altitudes. There is a need to recalibrate acclimatization strategies for improving health protection and adapting to the environmental variations at high altitudes. This narrative review details the geographical changes and physiological changes at high altitudes and presents a framework of acclimatization, pre-acclimatization, and pharmacological aspects of high-altitude survival to enhance the government efficacy and capacity for the strategic planning of acclimatization, use of therapeutics, and safe de-induction from high altitude for minimizing the life loss. It's simply too ambitious for the importance of the present review to reduce life loss, and it can be proved as the most essential aspect of the preparatory phase of high-altitude acclimatization in plateau regions without hampering the daily lifestyle. The application of pre-acclimatization techniques can be a boon for people serving at high altitudes, and it can be a short bridge for the rapid translocation of people at high altitudes by minimizing the acclimatization time.
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Affiliation(s)
- Poornima Sharma
- Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi, 110054, India
| | - Swaraj Mohanty
- Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi, 110054, India
| | - Yasmin Ahmad
- Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi, 110054, India
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Nourkami-Tutdibi N, Küllmer J, Dietrich S, Monz D, Zemlin M, Tutdibi E. Serum vascular endothelial growth factor is a potential biomarker for acute mountain sickness. Front Physiol 2023; 14:1083808. [PMID: 37064896 PMCID: PMC10098311 DOI: 10.3389/fphys.2023.1083808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Background: Acute mountain sickness (AMS) is the most common disease caused by hypobaric hypoxia (HH) in high-altitude (HA) associated with high mortality when progressing to high-altitude pulmonary edema (HAPE) and/or high-altitude cerebral edema (HACE). There is evidence for a role of pro- and anti-inflammatory cytokines in development of AMS, but biological pathways and molecular mechanisms underlying AMS remain elusive. We aimed to measure changes in blood cytokine levels and their possible association with the development of AMS.Method: 15 healthy mountaineers were included into this prospective clinical trial. All participants underwent baseline normoxic testing with venous EDTA blood sampling at the Bangor University in United Kingdom (69 m). The participants started from Beni at an altitude of 869 m and trekked same routes in four groups the Dhaulagiri circuit in the Nepali Himalaya. Trekking a 14-day route, the mountaineers reached the final HA of 5,050 m at the Hidden Valley Base Camp (HVBC). Venous EDTA blood sampling was performed after active ascent to HA the following morning after arrival at 5,050 m (HVBC). A panel of 21 cytokines, chemokines and growth factors were assessed using Luminex system (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-1ra, sIL-2Rα, IFN-γ, TNF-α, MCP-1, MIP-1α, MIP-1β, IP-10, G-CSF, GM-CSF, EGF, FGF-2, VEGF, and TGF-β1).Results: There was a significant main effect for the gradual ascent from sea-level (SL) to HA on nearly all cytokines. Serum levels for TNF-α, sIL-2Rα, G-CSF, VEGF, EGF, TGF-β1, IL-8, MCP-1, MIP-1β, and IP-10 were significantly increased at HA compared to SL, whereas levels for IFN-γ and MIP-1α were significantly decreased. Serum VEGF was higher in AMS susceptible versus AMS resistant subjects (p < 0.027, main effect of AMS) and increased after ascent to HA in both AMS groups (p < 0.011, main effect of HA). Serum VEGF increased more from SL values in the AMS susceptible group than in the AMS resistant group (p < 0.049, interaction effect).Conclusion: Cytokine concentrations are significantly altered in HA. Within short interval after ascent, cytokine concentrations in HH normalize to values at SL. VEGF is significantly increased in mountaineers suffering from AMS, indicating its potential role as a biomarker for AMS.
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Seiler T, Nakas CT, Brill AK, Hefti U, Hilty MP, Perret-Hoigné E, Sailer J, Kabitz HJ, Merz TM, Pichler Hefti J. Do cardiopulmonary exercise tests predict summit success and acute mountain sickness? A prospective observational field study at extreme altitude. Br J Sports Med 2023:bjsports-2022-106211. [PMID: 36898769 DOI: 10.1136/bjsports-2022-106211] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2023] [Indexed: 03/12/2023]
Abstract
OBJECTIVE During a high-altitude expedition, the association of cardiopulmonary exercise testing (CPET) parameters with the risk of developing acute mountain sickness (AMS) and the chance of reaching the summit were investigated. METHODS Thirty-nine subjects underwent maximal CPET at lowlands and during ascent to Mount Himlung Himal (7126 m) at 4844 m, before and after 12 days of acclimatisation, and at 6022 m. Daily records of Lake-Louise-Score (LLS) determined AMS. Participants were categorised as AMS+ if moderate to severe AMS occurred. RESULTS Maximal oxygen uptake (V̇O2max) decreased by 40.5%±13.7% at 6022 m and improved after acclimatisation (all p<0.001). Ventilation at maximal exercise (VEmax) was reduced at 6022 m, but higher VEmax was related to summit success (p=0.031). In the 23 AMS+ subjects (mean LLS 7.4±2.4), a pronounced exercise-induced oxygen desaturation (ΔSpO2exercise) was found after arrival at 4844 m (p=0.005). ΔSpO2exercise >-14.0% identified 74% of participants correctly with a sensitivity of 70% and specificity of 81% for predicting moderate to severe AMS. All 15 summiteers showed higher V̇O2max (p<0.001), and a higher risk of AMS in non-summiteers was suggested but did not reach statistical significance (OR: 3.64 (95% CI: 0.78 to 17.58), p=0.057). V̇O2max ≥49.0 mL/min/kg at lowlands and ≥35.0 mL/min/kg at 4844 m predicted summit success with a sensitivity of 46.7% and 53.3%, and specificity of 83.3% and 91.3%, respectively. CONCLUSION Summiteers were able to sustain higher VEmax throughout the expedition. Baseline V̇O2max below 49.0 mL/min/kg was associated with a high chance of 83.3% for summit failure, when climbing without supplemental oxygen. A pronounced drop of SpO2exercise at 4844 m may identify climbers at higher risk of AMS.
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Affiliation(s)
- Thomas Seiler
- Department of Pulmonary Medicine, Inselspital,Bern University Hospital, University of Bern, Bern, Switzerland
| | - Christos T Nakas
- Institute of Clinical Chemistry, Inselspital University Hospital, University of Bern, Bern, Switzerland.,Laboratory of Biometry, University of Thessaly, Volos, Greece
| | - Anne-Kathrin Brill
- Department of Pulmonary Medicine, Inselspital,Bern University Hospital, University of Bern, Bern, Switzerland
| | - Urs Hefti
- Swiss Sportclinic, Bern, Switzerland
| | - Matthias Peter Hilty
- Department of Intensive Care Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Eveline Perret-Hoigné
- Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Jannis Sailer
- Swiss Sportclinic, Bern, Switzerland.,Orthopedics and Traumatology, Hospital Nidwalden, Stans, Switzerland
| | - Hans-Joachim Kabitz
- Department of Internal Medicine II Pneumology Cardiology Intensive Care Medicine, Klinikum Konstanz, Konstanz, Germany
| | - Tobias M Merz
- Cardiovascular Intensive Care Unit, Auckland City Hospital, Auckland, New Zealand.,Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, University of Bern, Bern, Switzerland
| | - Jacqueline Pichler Hefti
- Department of Pulmonary Medicine, Inselspital,Bern University Hospital, University of Bern, Bern, Switzerland .,Swiss Sportclinic, Bern, Switzerland
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21
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Bellovary BN, Wells AD, Fennel ZJ, Ducharme JB, Houck JM, Mayschak TJ, Gibson AL, Drum SN, Mermier CM. Could Orthostatic Stress Responses Predict Acute Mountain Sickness Susceptibility Prior to High Altitude Travel? A Pilot Study. High Alt Med Biol 2023; 24:19-26. [PMID: 36473199 DOI: 10.1089/ham.2021.0177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Bellovary, Bryanne N., Andrew D. Wells, Zachary J. Fennel, Jeremy B. Ducharme, Jonathan M. Houck, Trevor J. Mayschak, Ann L. Gibson, Scott N. Drum, and Christine M. Mermier. Could orthostatic stress responses predict acute mountain sickness susceptibility before high altitude travel? A pilot study. High Alt Med Biol. 24:19-26, 2023. Purpose: This study assessed head-up tilt (HUT) responses in relation to acute mountain sickness (AMS)-susceptibility during hypoxic exposure. Materials and Methods: Fifteen participants completed three lab visits: (1) protocol familiarization and cycle maximal oxygen consumption (VO2max) test; (2) HUT test consisting of supine rest for 20 minutes followed by 70° tilting for ≤40 minutes; and (3) 6 hours of hypobaric hypoxic exposure (4,572 m) where participants performed two 30-minute cycling bouts separated by 1 hour at a 50% VO2max workload within the first 3 hours and rested when not exercising. During HUT, systolic blood pressure (SBP), diastolic blood pressure, heart rate (HR), and variability (blood pressure variability [BPV] and HR variability [HRV]) were measured continuously. The AMS scores were determined after 6 hours of exposure. Correlations determined relationships between HUT cardiovascular responses and AMS scores. Repeated-measures analysis of variance (ANOVA) assessed differences between those with and without AMS symptoms during HUT. Results: Higher AMS scores correlated with greater change in SBP variability (r = 0.52, p = 0.048) and blunted changes in HRV (root mean square of successive differences between normal heartbeats r = 0.81, p = 0.001, percentage of adjacent normal sinus intervals that differ by more than 50 milliseconds [pNN50] r = 0.87, p < 0.001) during HUT. A pNN50 interaction (p = 0.02) suggested elevated cardiac sympathetic activity at baseline and a blunted increase in cardiac sympathetic influence throughout HUT in those with AMS (pNN50 baseline: AMS = 26.2% ± 15.3%, no AMS = 51.0% ± 13.5%; first 3 minutes into HUT: AMS = 17.2% ± 19.1%, no AMS = 17.1% ± 10.9%; end of HUT: AMS = 6.2% ± 9.1%, no AMS 11.0% ± 10.0%). Conclusions: The results suggest autonomic responses via HUT differ in AMS-susceptible individuals. Changes in HRV and BPV during HUT may be a promising predictive measurement for AMS-susceptibility, but further research is needed for confirmation.
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Affiliation(s)
- Bryanne N Bellovary
- Kinesiology Department, State University of New York at Cortland, Cortland, New York, USA
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA
| | - Andrew D Wells
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA
- Department of Health and Exercise Science, Wake Forest University, Winston-Salem, North Carolina, USA
| | - Zachary J Fennel
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA
| | - Jeremy B Ducharme
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA
| | - Jonathan M Houck
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA
- Department of Science, Husson University, Bangor, Maine, USA
| | - Trevor J Mayschak
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA
- Department of Emergency Medicine, University of New Mexico, Albuquerque, New Mexico, USA
| | - Ann L Gibson
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA
| | - Scott N Drum
- Department of Health Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Christine M Mermier
- Department of Health, Exercise, and Sport Sciences, University of New Mexico, Albuquerque, New Mexico, USA
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22
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Viscor G, Corominas J, Carceller A. Nutrition and Hydration for High-Altitude Alpinism: A Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:3186. [PMID: 36833880 PMCID: PMC9965509 DOI: 10.3390/ijerph20043186] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/03/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
This report aims to summarise the scientific knowledge around hydration, nutrition, and metabolism at high altitudes and to transfer it into the practical context of extreme altitude alpinism, which, as far as we know, has never been considered before in the literature. Maintaining energy balance during alpine expeditions is difficult for several reasons and requires a deep understanding of human physiology and the biological basis for altitude acclimation. However, in these harsh conditions it is difficult to reconcile our current scientific knowledge in sports nutrition or even for mountaineering to high-altitude alpinism: extreme hypoxia, cold, and the logistical difficulties intrinsic to these kinds of expeditions are not considered in the current literature. Requirements for the different stages of an expedition vary dramatically with increasing altitude, so recommendations must differentiate whether the alpinist is at base camp, at high-altitude camps, or attempting the summit. This paper highlights nutritional recommendations regarding prioritising carbohydrates as a source of energy and trying to maintain a protein balance with a practical contextualisation in the extreme altitude environment in the different stages of an alpine expedition. More research is needed regarding specific macro and micronutrient requirements as well as the adequacy of nutritional supplementations at high altitudes.
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Affiliation(s)
- Ginés Viscor
- Secció de Fisiologia, Departament de Biologia Cel·Lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Jordi Corominas
- International Federation of Mountain Guide Associations (UIAGM/IFMGA), CH-1920 Bern, Switzerland
| | - Anna Carceller
- Secció de Fisiologia, Departament de Biologia Cel·Lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain
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23
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A systematic review of electrocardiographic changes in populations temporarily ascending to high altitudes. Curr Probl Cardiol 2023; 48:101630. [PMID: 36731688 DOI: 10.1016/j.cpcardiol.2023.101630] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 01/23/2023] [Indexed: 02/01/2023]
Abstract
High altitudes can cause hypobaric hypoxia, altering human physiology and the corresponding electrocardiogram (ECG). As part of the Altitude Nondifferentiated ECG Study (ANDES), this paper reviews ECG changes in subjects ascending to high altitudes. This review was conducted following PRISMA guidelines. PubMed, EMBASE, OVID Medline, and Web of Science were searched. 19 studies were ultimately included. Notable ECG changes at high altitudes include T wave inversion in the precordial leads and rightward QRS axis deviation in leads I, II and aVF. Less common findings were increases in P wave amplitude, QRS amplitude, and QTc interval. These ECG deviations typically self-resolved within 2-6 weeks following return to sea level. Consideration must be taken when interpreting ECG changes in individuals during ascent to, at, or upon return from high altitudes. Further large-scale studies are needed to elucidate temporal and altitude-dependent ECG patterns and establish reference standards for clinicians.
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24
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Eisenberger L, Mayr B, Beck M, Venek V, Kranzinger C, Menzl A, Jahn I, Sareban M, Oberhoffer-Fritz R, Niebauer J, Böhm B. Assessment of Exercise Intensity for Uphill Walking in Healthy Adults Performed Indoors and Outdoors. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:16662. [PMID: 36554543 PMCID: PMC9779799 DOI: 10.3390/ijerph192416662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/02/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Borg's rating of perceived exertion (BRPE) scale is a simple, but subjective tool to grade physical strain during exercise. As a result, it is widely used for the prescription of exercise intensity, especially for cardiovascular disease prevention. The purpose of this study was to assess and compare relationships between BRPE and physiological measures of exercise intensity during uphill walking indoors and outdoors. METHODS 134 healthy participants [median age: 56 years (IQR 52-63)] completed a maximal graded walking test indoors on a treadmill using the modified Bruce protocol, and a submaximal 1 km outdoor uphill cardio-trekking test (1 km CTT). Heart rate (HR) and oxygen consumption (V̇O2) were continuously measured throughout both tests. BRPE was simultaneously assessed at the end of each increment on the treadmill, while the maximal BRPE value was noted at the end of the 1 km CTT. RESULTS On the treadmill, BRPE correlated very high with relative HR (%HRmax) (ρ = 0.88, p < 0.001) and V̇O2 (%V̇O2max) (ρ = 0.89, p < 0.001). During the 1 km CTT, a small correlation between BRPE and %HRmax (ρ = 0.24, p < 0.05), respectively %V̇O2max was found (ρ = 0.24, p < 0.05). CONCLUSIONS Criterion validity of BRPE during uphill walking depends on the environment and is higher during a treadmill test compared to a natural environment. Adding sensor-based, objective exercise-intensity parameters such as HR holds promise to improve intensity prescription and health safety during uphill walking in a natural environment.
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Affiliation(s)
- Laura Eisenberger
- Institute of Preventive Pediatrics, Faculty of Sport and Health Sciences, Technical University of Munich, 80992 Munich, Germany
| | - Barbara Mayr
- Institute of Sports Medicine, Prevention and Rehabilitation and Research Institute of Molecular Sports Medicine and Rehabilitation, Paracelsus Medical University, 5020 Salzburg, Austria
- Ludwig Boltzmann Institute for Digital Health and Prevention, 5020 Salzburg, Austria
| | - Maximilian Beck
- Ludwig Boltzmann Institute for Digital Health and Prevention, 5020 Salzburg, Austria
| | - Verena Venek
- Salzburg Research Forschungsgesellschaft mbH, 5020 Salzburg, Austria
- Department of Medical Engineering, Carinthia University of Applied Sciences, 9524 Villach, Austria
| | | | - Andrea Menzl
- St. Irmingard Klinik Prien, Clinic for Cardiology, 83209 Prien am Chiemsee, Germany
| | - Inga Jahn
- St. Irmingard Klinik Prien, Clinic for Cardiology, 83209 Prien am Chiemsee, Germany
| | - Mahdi Sareban
- Institute of Sports Medicine, Prevention and Rehabilitation and Research Institute of Molecular Sports Medicine and Rehabilitation, Paracelsus Medical University, 5020 Salzburg, Austria
- Ludwig Boltzmann Institute for Digital Health and Prevention, 5020 Salzburg, Austria
| | - Renate Oberhoffer-Fritz
- Institute of Preventive Pediatrics, Faculty of Sport and Health Sciences, Technical University of Munich, 80992 Munich, Germany
| | - Josef Niebauer
- Institute of Sports Medicine, Prevention and Rehabilitation and Research Institute of Molecular Sports Medicine and Rehabilitation, Paracelsus Medical University, 5020 Salzburg, Austria
- Ludwig Boltzmann Institute for Digital Health and Prevention, 5020 Salzburg, Austria
| | - Birgit Böhm
- Institute of Preventive Pediatrics, Faculty of Sport and Health Sciences, Technical University of Munich, 80992 Munich, Germany
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25
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Furian M, Tannheimer M, Burtscher M. Effects of Acute Exposure and Acclimatization to High-Altitude on Oxygen Saturation and Related Cardiorespiratory Fitness in Health and Disease. J Clin Med 2022; 11:jcm11226699. [PMID: 36431176 PMCID: PMC9697047 DOI: 10.3390/jcm11226699] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Maximal values of aerobic power (VO2max) and peripheral oxygen saturation (SpO2max) decline in parallel with gain in altitude. Whereas this relationship has been well investigated when acutely exposed to high altitude, potential benefits of acclimatization on SpO2 and related VO2max in healthy and diseased individuals have been much less considered. Therefore, this narrative review was primarily aimed to identify relevant literature reporting altitude-dependent changes in determinants, in particular SpO2, of VO2max and effects of acclimatization in athletes, healthy non-athletes, and patients suffering from cardiovascular, respiratory and/or metabolic diseases. Moreover, focus was set on potential differences with regard to baseline exercise performance, age and sex. Main findings of this review emphasize the close association between individual SpO2 and VO2max, and demonstrate similar altitude effects (acute and during acclimatization) in healthy people and those suffering from cardiovascular and metabolic diseases. However, in patients with ventilatory constrains, i.e., chronic obstructive pulmonary disease, steep decline in SpO2 and V̇O2max and reduced potential to acclimatize stress the already low exercise performance. Finally, implications for prevention and therapy are briefly discussed.
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Affiliation(s)
- Michael Furian
- Pulmonary Division, University Hospital Zurich, 8092 Zurich, Switzerland
- Research Department, Swiss University of Traditional Chinese Medicine, 5330 Bad Zurzach, Switzerland
| | - Markus Tannheimer
- Department of Sport and Rehabilitation Medicine, University of Ulm, 89075 Ulm, Germany
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, 6020 Innsbruck, Austria
- Correspondence:
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26
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Cerda-Kohler H, Haichelis D, Reuquén P, Miarka B, Homer M, Zapata-Gómez D, Aedo-Muñoz E. Training at moderate altitude improves submaximal but not maximal performance-related parameters in elite rowers. Front Physiol 2022; 13:931325. [PMID: 36311238 PMCID: PMC9614325 DOI: 10.3389/fphys.2022.931325] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 09/30/2022] [Indexed: 11/13/2022] Open
Abstract
Maximal oxygen consumption (V̇O2max), physiological thresholds, and hemoglobin mass are strong predictors of endurance performance. High values of V̇O2max, maximal aerobic power (MAP), and power output at anaerobic thresholds are key variables in elite rowers. Endurance athletes often use altitude training as a strategy to improve performance. However, no clear evidence exists that training at natural altitude enhances sea-level performance in elite rowers. This study aimed to evaluate the effect of altitude training on rowing-performance parameters at sea level. The study was conducted on eleven rowers (Six females, five males) from the Chilean National Team during a 3-week moderate altitude training (∼2,900 m. a.s.l.) under the live high-train high (LHTH) model. It included a rowing ergometer maximal incremental test and blood analysis (pre and post-altitude). Gas exchange analysis was performed to measure V̇O2max, ventilatory thresholds (VTs) and rowing economy/efficiency (ECR/GE%). LHTL training improves performance-related variables at sea level (V̇Emax: 3.3% (95% CI, 1.2–5.5); hemoglobin concentration ([Hb]): 4.3% (95% CI, 1.7–6.9); hematocrit (%): 4.5% (95% CI, 0.9–8.2); RBC (red blood cells) count: 5.3% (95% CI, 2.3–8.2); power at VT2: 6.9% (95% CI, 1.7–12.1), V̇EVT2: 6.4% (95% CI, 0.4–12.4); power at VT1: 7.3% (95% CI, 1.3–13.3), V̇EVT1: 8.7% (95% CI, 1.6–15.8)) and economy/efficiency-related variables (ECRVT2: 5.3% (95% CI, −0.6 to −10.0); GE(%): 5.8% (95% CI, 0.8–10.7)). The LHTH training decreased breathing economy at MAP (−2.8% (95% CI, 0.1–5.6)), pVT2 (−9.3% (95% CI, −5.9 to −12.7)), and pVT1 (−9.3% (95% CI, −4.1 to −14.4)). Non-significant changes were found for V̇O2max and MAP. This study describes the effects of a 3-week moderate altitude (LHTH training) on performance and economy/efficiency-related variables in elite rowers, suggesting that it is an excellent option to induce positive adaptations related to endurance performance.
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Affiliation(s)
- Hugo Cerda-Kohler
- Escuela de Ciencias del Deporte y Actividad Física, Facultad de Salud, Universidad Santo Tomás, Santiago, Chile
- Departamento de Educación Física, eporte y Recreación, Facultad de Artes y Educación Física, Universidad Metropolitana de Ciencias de la Educación, Santiago, Chile
- Laboratory of Psychophysiology and Performance in Sports and Combats, Postgraduate Program in Physical Education, School of Physical Education and Sport, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Unidad de Fisiología del Ejercicio, Centro de Innovación, Clínica MEDS, Santiago, Chile
| | - Danni Haichelis
- Unidad de Fisiología del Ejercicio, Centro de Innovación, Clínica MEDS, Santiago, Chile
- Unidad de Ciencias Aplicadas al Deporte, Instituto Nacional de Deportes, Santiago, Chile
| | - Patricia Reuquén
- Unidad de Ciencias Aplicadas al Deporte, Instituto Nacional de Deportes, Santiago, Chile
- Escuela de Ciencias de la Actividad Física, el Deporte y la Salud, Universidad de Santiago de Chile, Santiago, Chile
- Laboratorio de Ciencias de la Actividad Física, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Bianca Miarka
- Laboratory of Psychophysiology and Performance in Sports and Combats, Postgraduate Program in Physical Education, School of Physical Education and Sport, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mark Homer
- School of Human and Social Sciences, Buckinghamshire New University, Buckinghamshire, United Kingdom
| | - Daniel Zapata-Gómez
- Unidad de Ciencias Aplicadas al Deporte, Instituto Nacional de Deportes, Santiago, Chile
| | - Esteban Aedo-Muñoz
- Laboratory of Psychophysiology and Performance in Sports and Combats, Postgraduate Program in Physical Education, School of Physical Education and Sport, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Unidad de Ciencias Aplicadas al Deporte, Instituto Nacional de Deportes, Santiago, Chile
- Escuela de Ciencias de la Actividad Física, el Deporte y la Salud, Universidad de Santiago de Chile, Santiago, Chile
- *Correspondence: Esteban Aedo-Muñoz,
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27
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Usaj A, Kapus J, Štrumbelj B, Debevec T, Vodičar J. Effects of Moderate Altitude Training Combined with Moderate or High-altitude Residence. Int J Sports Med 2022; 43:1129-1136. [PMID: 35926513 DOI: 10.1055/a-1885-4053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
We aimed to identify potential physiological and performance differences of trained cross-country skiers (V˙o2max=60±4 ml ∙ kg-1 ∙ min-1) following two, 3-week long altitude modalities: 1) training at moderate altitudes (600-1700 m) and living at 1500 m (LMTM;N=8); and 2) training at moderate altitudes (600-1700 m) and living at 1500 m with additional nocturnal normobaric hypoxic exposures (FiO2 =0.17;LHTM; N=8). All participants conducted the same training throughout the altitude training phase and underwent maximal roller ski trials and submaximal cyclo-ergometery before, during and one week after the training camps. No exercise performance or hematological differences were observed between the two modalities. The average roller ski velocities were increased one week after the training camps following both LMTM (p=0.03) and LHTM (p=0.04) with no difference between the two (p=0.68). During the submaximal test, LMTM increased the Tissue Oxygenation Index (11.5±6.5 to 1.0±8.5%; p=0.04), decreased the total hemoglobin concentration (15.1±6.5 to 1.7±12.9 a.u.;p=0.02), and increased blood pH (7.36±0.03 to 7.39±0.03;p=0.03). On the other hand, LHTM augmented minute ventilation (76±14 to 88±10 l·min-1;p=0.04) and systemic blood oxygen saturation by 2±1%; (p=0.02) with no such differences observed following the LMTM. Collectively, despite minor physiological differences observed between the two tested altitude training modalities both induced comparable exercise performance modulation.
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Affiliation(s)
- Anton Usaj
- Laboratory of Biodynamics, Faculty of Sport, University of Ljubljana, Slovenia
| | - Jernej Kapus
- Laboratory of Biodynamics, Faculty of Sport, University of Ljubljana, Slovenia
| | - Boro Štrumbelj
- Laboratory of Biodynamics, Faculty of Sport, University of Ljubljana, Slovenia
| | - Tadej Debevec
- Laboratory of Biodynamics, Faculty of Sport, University of Ljubljana, Slovenia.,Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Janez Vodičar
- Institute of Sport, Faculty of Sport, University of Ljubljana, Slovenia
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28
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Hohenauer E, Freitag L, Herten M, Siallagan J, Pollock E, Taube W, Clijsen R. The Methodological Quality of Studies Investigating the Acute Effects of Exercise During Hypoxia Over the Past 40 years: A Systematic Review. Front Physiol 2022; 13:919359. [PMID: 35784889 PMCID: PMC9243659 DOI: 10.3389/fphys.2022.919359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/09/2022] [Indexed: 11/25/2022] Open
Abstract
Exercise under hypoxia and the physiological impact compared to normoxia or hypoxia has gained attention in the last decades. However, methodological quality assessment of articles in this area is lacking in the literature. Therefore, this article aimed to evaluate the methodologic quality of trials studying exercise under hypoxia. An electronic search was conducted until December 2021. The search was conducted in PubMed, CENTRAL, and PEDro using the PICO model. (P) Participants had to be healthy, (I) exercise under normobaric or hypobaric hypoxia had to be (C) compared to exercise in normoxia or hypoxia on (O) any physiological outcome. The 11-item PEDro scale was used to assess the methodological quality (internal validity) of the studies. A linear regression model was used to evaluate the evolution of trials in this area, using the total PEDro score of the rated trials. A total of n = 81 studies met the inclusion criteria and were processed in this study. With a mean score of 5.1 ± 0.9 between the years 1982 and 2021, the mean methodological quality can be described as “fair.” Only one study reached the highest score of 8/10, and n = 2 studies reached the lowest observed value of 3/10. The linear regression showed an increase of the PEDro score of 0.1 points per decade. A positive and small tendency toward increased methodologic quality was observed. The current results demonstrate that a positive and small tendency can be seen for the increase in the methodological quality in the field of exercise science under hypoxia. A “good” methodological quality, reaching a PEDro score of 6 points can be expected in the year 2063, using a linear regression model analysis. To accelerate this process, future research should ensure that methodological quality criteria are already included during the planning phase of a study.
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Affiliation(s)
- 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
- *Correspondence: Erich Hohenauer,
| | - Livia Freitag
- 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
| | - Miriam Herten
- 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
| | - Julia Siallagan
- 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
| | - Elke Pollock
- Department of Physiotherapy, Zurich University of Applied Sciences, Zurich, Switzerland
| | - Wolfgang Taube
- Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland
| | - Ron Clijsen
- 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 Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium
- Department of Health, Bern University of Applied Sciences, Berne, Switzerland
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Chen P, Liu Y, Liu W, Wang Y, Liu Z, Rong M. Impact of High-Altitude Hypoxia on Bone Defect Repair: A Review of Molecular Mechanisms and Therapeutic Implications. Front Med (Lausanne) 2022; 9:842800. [PMID: 35620712 PMCID: PMC9127390 DOI: 10.3389/fmed.2022.842800] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 04/15/2022] [Indexed: 11/23/2022] Open
Abstract
Reaching areas at altitudes over 2,500–3,000 m above sea level has become increasingly common due to commerce, military deployment, tourism, and entertainment. The high-altitude environment exerts systemic effects on humans that represent a series of compensatory reactions and affects the activity of bone cells. Cellular structures closely related to oxygen-sensing produce corresponding functional changes, resulting in decreased tissue vascularization, declined repair ability of bone defects, and longer healing time. This review focuses on the impact of high-altitude hypoxia on bone defect repair and discusses the possible mechanisms related to ion channels, reactive oxygen species production, mitochondrial function, autophagy, and epigenetics. Based on the key pathogenic mechanisms, potential therapeutic strategies have also been suggested. This review contributes novel insights into the mechanisms of abnormal bone defect repair in hypoxic environments, along with therapeutic applications. We aim to provide a foundation for future targeted, personalized, and precise bone regeneration therapies according to the adaptation of patients to high altitudes.
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Affiliation(s)
- Pei Chen
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Yushan Liu
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Wenjing Liu
- Department of Prosthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Yarong Wang
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Ziyi Liu
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Mingdeng Rong
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
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30
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Narang BJ, Manferdelli G, Millet GP, Debevec T. Respiratory responses to hypoxia during rest and exercise in individuals born pre-term: a state-of-the-art review. Eur J Appl Physiol 2022; 122:1991-2003. [PMID: 35589858 DOI: 10.1007/s00421-022-04965-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 04/28/2022] [Indexed: 11/28/2022]
Abstract
The pre-term birth survival rate has increased considerably in recent decades, and research investigating the long-term effects of premature birth is growing. Moreover, altitude sojourns are increasing in popularity and are often accompanied by various levels of physical activity. Individuals born pre-term appear to exhibit altered acute ventilatory responses to hypoxia, potentially predisposing them to high-altitude illness. These impairments are likely due to the use of perinatal hyperoxia stunting the maturation of carotid body chemoreceptors, but may also be attributed to limited lung diffusion capacity and/or gas exchange inefficiency. Aerobic exercise capacity also appears to be reduced in this population. This may relate to the aforementioned respiratory impairments, or could be due to physiological limitations in pulmonary blood flow or at the exercising muscle (e.g. mitochondrial efficiency). However, surprisingly, the debilitative effects of exercise when performed at altitude do not seem to be exacerbated by premature birth. In fact, it is reasonable to speculate that pre-term birth could protect against the consequences of exercise combined with hypoxia. The mechanisms that underlie this assertion might relate to differences in oxidative stress responses or in cardiopulmonary morphology in pre-term individuals, compared to their full-term counterparts. Further research is required to elucidate the independent effects of neonatal treatment, sex differences and chronic lung disease, and to establish causality in some of the proposed mechanisms that could underlie the differences discussed throughout this review. A more in-depth understanding of the acclimatisation responses to chronic altitude exposures would also help to inform appropriate interventions in this clinical population.
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Affiliation(s)
- Benjamin J Narang
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Jamova Cesta 39, 1000, Ljubljana, Slovenia. .,Faculty for Sport, University of Ljubljana, Ljubljana, Slovenia.
| | | | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Jamova Cesta 39, 1000, Ljubljana, Slovenia.,Faculty for Sport, University of Ljubljana, Ljubljana, Slovenia
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31
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Hypoxia and hemorheological properties in older individuals. Ageing Res Rev 2022; 79:101650. [PMID: 35597435 DOI: 10.1016/j.arr.2022.101650] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/20/2022] [Accepted: 05/13/2022] [Indexed: 12/17/2022]
Abstract
Hypoxia is caused by insufficient oxygen availability for the organism leading to reduced oxygen delivery to tissues and cells. It has been regarded as a severe threat to human health and it is indeed implicated in pathophysiological mechanisms involved in the development and progression of many diseases. Nevertheless, the potential of controlled hypoxia interventions (i.e. hypoxia conditioning) for improving cardio-vascular health is gaining increased attention. However, blood rheology is often a forgotten factor for vascular health while aging and hypoxia exposure are both suspected to alter hemorheological properties. These changes in blood rheology may influence the benefits-risks balance of hypoxia exposure in older individuals. The benefits of hypoxia exposure for vascular health are mainly reported for healthy populations and the combined impact of aging and hypoxia on blood rheology could therefore be deleterious in older individuals. This review discusses evidence of hypoxia-related and aging-related changes in blood viscosity and its determinants. It draws upon an extensive literature search on the effects of hypoxia/altitude and aging on blood rheology. Aging increases blood viscosity mainly through a rise in plasma viscosity, red blood cell (RBC) aggregation and a decrease in RBC deformability. Hypoxia also causes an increase in RBC aggregation and plasma viscosity. In addition, hypoxia exposure may increase hematocrit and modulate RBC deformability, depending on the hypoxic dose, i.e, beneficial effect of intermittent hypoxia with moderate dose vs deleterious effect of chronic continuous or intermittent hypoxia or if the hypoxic dose is too high. Special attention is directed toward the risks vs. benefits of hemorheological changes during hypoxia exposure in older individuals, and its clinical relevance for vascular disorders.
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Karlsson Ø, Laaksonen MS, McGawley K. Monitoring Acclimatization and Training Responses Over 17–21 Days at 1,800 m in Elite Cross-Country Skiers and Biathletes. Front Sports Act Living 2022; 4:852108. [PMID: 35647539 PMCID: PMC9130592 DOI: 10.3389/fspor.2022.852108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/11/2022] [Indexed: 11/17/2022] Open
Abstract
Objective To monitor the daily variations and time course of changes in selected variables during a 17–21-day altitude training camp at 1,800 m in a group of elite cross-country skiers (9 women, 12 men) and biathletes (7 women, 4 men). Methods Among other variables, resting peripheral oxygen saturation (SpO2rest), resting heart rate (HRrest) and urine specific gravity (USG) were monitored daily at altitude, while illness symptoms were monitored weekly. Before and after the camp, body composition (i.e., lean and fat mass) and body mass were assessed in all athletes, while roller-skiing speed at a blood lactate concentration of 4 mmol·L−1 (Speed@4mmol) was assessed in the biathletes only. Results Neither SpO2rest, HRrest nor USG changed systematically during the camp (p > 0.05), although some daily time points differed from day one for the latter two variables (p < 0.05). In addition, body composition and body mass were unchanged from before to after the camp (p > 0.05). Eleven out of 15 illness episodes were reported within 4 days of the outbound or homebound flight. The five biathletes who remained free of illness increased their Speed@4mmol by ~ 4% from before to after the camp (p = 0.031). Conclusions The present results show that measures typically recommended to monitor acclimatization and responses to altitude in athletes (e.g., SpO2rest and HRrest) did not change systematically over time. Further research is needed to explore the utility of these and other measures in elite endurance athletes at altitudes typical of competition environments.
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Spinella G, Tidu L, Grassato L, Musella V, Matarazzo M, Valentini S. Military Working Dogs Operating in Afghanistan Theater: Comparison between Pre- and Post-Mission Blood Analyses to Monitor Physical Fitness and Training. Animals (Basel) 2022; 12:ani12050617. [PMID: 35268187 PMCID: PMC8909791 DOI: 10.3390/ani12050617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 11/21/2022] Open
Abstract
Simple Summary In modern conflicts, one of the greatest risks for military personnel is represented by explosive devices. For this reason, specifically trained dogs able to detect explosives have been more and more intensively used in humanitarian military operations. However, at present, literature regarding working problems reported by these animals is very limited. The a of this study was to evaluate the health status of military dogs participating in humanitarian missions to Afghanistan, comparing their pre- and post-mission blood work. Dogs were first considered together as a group and then divided in groups by age, sex, breed and mission length. The results of the study show that there are no particular differences between their blood work before and after the missions. This indicates that the recorded dogs were physically well prepared to face their tasks. Abstract The intergovernmental organization known as the United Nations (UN) was born “to maintain international peace and security” through different operations and tasks, including “mine action” and “explosive detection”. Explosives are the most frequent cause of injuries in military personnel and an enormous danger for civilians. The role of explosive detection dogs (EDDs) and mine detection dogs has gained great consideration over time, leading to their intense use in military operations. Literature regarding working injuries reported by EDDs during missions is limited. The aim of the present study is to investigate the hematological changes that occurred between pre- and post-mission blood analyses in military working dogs deployed to Afghanistan in order to evaluate signs of health problems or physical adjustments. Examining the clinical records, only three dogs reported a medical issue, one with gastric dilatation-volvulus (GDV), and two with lameness episodes. Lack of health issues occurring during the missions was reflected by the absence of significant differences between pre- and post-mission blood analyses. Blood results were also examined by dividing the EDDs into groups considering age at departure, sex, breed and mission length. A few categories demonstrated significant changes in some parameters; however, the mean values were always included in the ranges of normality, indicating that their physical fitness and training were adequate for the required tasks.
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Affiliation(s)
- Giuseppe Spinella
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano dell’Emilia, BO, Italy;
| | - Lorenzo Tidu
- “Vittorio Veneto” Division Florence-NATO Multinational Division South, 50136 Firenze, FI, Italy;
| | - Lisa Grassato
- Veterinary Clinic “Il Podere”, 31038 Postioma, TV, Italy
- Correspondence: (L.G.); (S.V.)
| | - Vincenzo Musella
- Department of Health Sciences, University of Catanzaro, 88100 Germaneto, CZ, Italy;
| | | | - Simona Valentini
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano dell’Emilia, BO, Italy;
- Correspondence: (L.G.); (S.V.)
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Fieten KB, Drijver‐Messelink MT, Cogo A, Charpin D, Sokolowska M, Agache I, Taborda‐Barata LM, Eguiluz‐Gracia I, Braunstahl GJ, Seys SF, den Berge M, Bloch KE, Ulrich S, Cardoso‐Vigueros C, Kappen JH, Brinke AT, Koch M, Traidl‐Hoffmann C, da Mata P, Prins DJ, Pasmans SGMA, Bendien S, Rukhadze M, Shamji MH, Couto M, Oude Elberink H, Peroni DG, Piacentini G, Weersink EJM, Bonini M, Rijssenbeek‐Nouwens LHM, Akdis CA. Alpine altitude climate treatment for severe and uncontrolled asthma: An EAACI position paper. Allergy 2022; 77:1991-2024. [PMID: 35113452 PMCID: PMC9305916 DOI: 10.1111/all.15242] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/14/2022] [Accepted: 01/30/2022] [Indexed: 12/30/2022]
Abstract
Currently available European Alpine Altitude Climate Treatment (AACT) programs combine the physical characteristics of altitude with the avoidance of environmental triggers in the alpine climate and a personalized multidisciplinary pulmonary rehabilitation approach. The reduced barometric pressure, oxygen pressure, and air density, the relatively low temperature and humidity, and the increased UV radiation at moderate altitude induce several physiological and immunological adaptation responses. The environmental characteristics of the alpine climate include reduced aeroallergens such as house dust mites (HDM), pollen, fungi, and less air pollution. These combined factors seem to have immunomodulatory effects controlling pathogenic inflammatory responses and favoring less neuro‐immune stress in patients with different asthma phenotypes. The extensive multidisciplinary treatment program may further contribute to the observed clinical improvement by AACT in asthma control and quality of life, fewer exacerbations and hospitalizations, reduced need for oral corticosteroids (OCS), improved lung function, decreased airway hyperresponsiveness (AHR), improved exercise tolerance, and improved sinonasal outcomes. Based on observational studies and expert opinion, AACT represents a valuable therapy for those patients irrespective of their asthma phenotype, who cannot achieve optimal control of their complex condition despite all the advances in medical science and treatment according to guidelines, and therefore run the risk of falling into a downward spiral of loss of physical and mental health. In the light of the observed rapid decrease in inflammation and immunomodulatory effects, AACT can be considered as a natural treatment that targets biological pathways.
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Webb KL, Dominelli PB, Baker SE, Klassen SA, Joyner MJ, Senefeld JW, Wiggins CC. Influence of High Hemoglobin-Oxygen Affinity on Humans During Hypoxia. Front Physiol 2022; 12:763933. [PMID: 35095551 PMCID: PMC8795792 DOI: 10.3389/fphys.2021.763933] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/22/2021] [Indexed: 01/11/2023] Open
Abstract
Humans elicit a robust series of physiological responses to maintain adequate oxygen delivery during hypoxia, including a transient reduction in hemoglobin-oxygen (Hb-O2) affinity. However, high Hb-O2 affinity has been identified as a beneficial adaptation in several species that have been exposed to high altitude for generations. The observed differences in Hb-O2 affinity between humans and species adapted to high altitude pose a central question: is higher or lower Hb-O2 affinity in humans more advantageous when O2 availability is limited? Humans with genetic mutations in hemoglobin structure resulting in high Hb-O2 affinity have shown attenuated cardiorespiratory adjustments during hypoxia both at rest and during exercise, providing unique insight into this central question. Therefore, the purpose of this review is to examine the influence of high Hb-O2 affinity during hypoxia through comparison of cardiovascular and respiratory adjustments elicited by humans with high Hb-O2 affinity compared to those with normal Hb-O2 affinity.
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Affiliation(s)
- Kevin L. Webb
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
| | | | - Sarah E. Baker
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
| | - Stephen A. Klassen
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
| | - Michael J. Joyner
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
| | - Jonathon W. Senefeld
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
| | - Chad C. Wiggins
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States
- *Correspondence: Chad C. Wiggins,
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36
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Dautova A, Khazhieva E, Isaeva E, Khabibulinna I, Shamratova V. Influence of motor activity and polymorphism I/D of ACE on the affinity of oxygen for hemoglobin. BIO WEB OF CONFERENCES 2022. [DOI: 10.1051/bioconf/20224801020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The influence of rs4646994 polymorphism of the ACE gene on the affinity of oxygen for hemoglobin among young men with different levels of physical activity has been studied. 245 young men aged 20-22 years were included in the study. All young men were divided into three groups depending on their motor activity: low (LMA), average (AMA) and high (HMA). SatO2, pO2, pCO2, p50 and HbO2 were analyzed in capillary blood of all examined young men. It was found out that I/I genotype of the ACE gene is associated with a decrease in the affinity of oxygen for hemoglobin both in LMA (p=0.022) and in HMA (p=0.000096). The intensification of physical activity among I/D and D/D genotypes is accompanied by an increase in the level of hemoglobin oxygenation in blood, while the I/I genotype with part of HbO2 does not change depending on motor activity. These features can be explained by the shift of the oxygen dissociation curve to the left among young men with the *D allele genotype, with an increase in physical activity. On the contrary, the I/I genotype of the ACE gene have efficient oxygen extraction to tissues, regardless of the level of motor activity compared to the D/D genotype.
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Alcantara-Zapata DE, Llanos AJ, Nazzal C. High altitude exposure affects male reproductive parameters: Could it also affect the prostate?†. Biol Reprod 2021; 106:385-396. [PMID: 34725677 DOI: 10.1093/biolre/ioab205] [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: 08/16/2021] [Revised: 10/26/2021] [Indexed: 11/14/2022] Open
Abstract
Living at high altitudes and living with prostatic illness are two different conditions closely related to a hypoxic environment. People at high altitudes exposed to acute, chronic, or intermittent hypobaric hypoxia turn on several mechanisms at the system, cellular and molecular level to cope with oxygen atmosphere scarcity maintaining the oxygen homeostasis. This exposure affects the whole organism and function of many systems, such as cardiovascular, respiratory, and reproductive. On the other hand, malignant prostate is related to the scarcity of oxygen in the tissue microenvironment due to its low availability and high consumption due to the swift cell proliferation rates. Based on the literature, this similarity in the oxygen scarcity suggests that hypobaric hypoxia, and other common factors between these two conditions, could be involved in the aggravation of the pathological prostatic status. However, there is still a lack of evidence in the association of this disease in males at high altitudes. This review aims to examine the possible mechanisms that hypobaric hypoxia might negatively add to the pathological prostate function in males who live and work at high altitudes. More profound investigations of hypobaric hypoxia's direct action on the prostate could help understand this exposure's effect and prevent worse prostate illness impact in males at high altitudes.
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Affiliation(s)
| | - Aníbal J Llanos
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Centro Internacional de Estudios Andinos (INCAS), Universidad de Chile, Santiago, Chile
| | - Carolina Nazzal
- Department of Epidemiology. School of Public Health. Faculty of Medicine. University of Chile
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Calleja-Romero A, Vicente-Rodríguez G, Garatachea N. Acute effects of long-distance races on heart rate variability and arterial stiffness: A systematic review and meta-analysis. J Sports Sci 2021; 40:248-270. [PMID: 34720045 DOI: 10.1080/02640414.2021.1986276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
This study systematically reviewed and quantified the effects of running a long-distance race (LDR) on heart rate variability (HRV) and arterial stiffness (AS). All types of races of a distance equal to or greater than a marathon (≥42.2 km) were included. A total of 2,220 articles were identified, 52 were included in the qualitative analysis, and 48 were meta-analysed. The standardised mean difference pre- and post-race of various time-domain and frequency-domain indices of HRV, mean arterial blood pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP) and carotid-femoral pulse wave velocity (cfPWV) was calculated. Regarding HRV, there was a significant decrease in most of the variables considered as markers of parasympathetic activity, indicating a shift of autonomic balance towards a reduced vagal tone. Regarding vascular variables, there was a significant drop in blood pressure and reduced AS. In conclusion, running an LDR seems to have a considerable acute effect on the autonomic nervous system, haemodynamics, and vascular properties. The observed effects could be categorised within the expected acute responses to long-lasting, strenuous exercise.
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Affiliation(s)
- Alberto Calleja-Romero
- Faculty of Health and Sport Science (Fcsd, Ronda Misericordia 5, 22001-Huesca, Spain), Department of Physiatry and Nursing, University of Zaragoza, Huesca, Spain
| | - Germán Vicente-Rodríguez
- Faculty of Health and Sport Science (Fcsd, Ronda Misericordia 5, 22001-Huesca, Spain), Department of Physiatry and Nursing, University of Zaragoza, Huesca, Spain.,Growth, Exercise, Nutrition and Development Group and IIS-Aragon, Spain.,Centro De Investigación Biomédica En Red De Fisiopatología De La Obesidad Y Nutrición (Ciber-obn), Madrid, Spain.,Instituto Agroalimentario De Aragón -ia2- (Cita-universidad De Zaragoza), Zaragoza, Spain
| | - Nuria Garatachea
- Faculty of Health and Sport Science (Fcsd, Ronda Misericordia 5, 22001-Huesca, Spain), Department of Physiatry and Nursing, University of Zaragoza, Huesca, Spain.,Growth, Exercise, Nutrition and Development Group and IIS-Aragon, Spain.,Centro De Investigación Biomédica En Red De Fisiopatología De La Obesidad Y Nutrición (Ciber-obn), Madrid, Spain.,Instituto Agroalimentario De Aragón -ia2- (Cita-universidad De Zaragoza), Zaragoza, Spain
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Paris HL, Sinai EC, Shei RJ, Keller AM, Mickleborough TD. The influence of carbohydrate ingestion on peripheral and central fatigue during exercise in hypoxia: A narrative review. Eur J Sport Sci 2021; 21:1423-1435. [PMID: 33106121 PMCID: PMC8140067 DOI: 10.1080/17461391.2020.1842512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Hypoxia impairs aerobic performance by accelerating fatiguing processes. These processes may originate from sites either distal (peripheral) or proximal (central) to the neuromuscular junction, though these are not mutually exclusive. Peripheral mechanisms include decrements in muscle glycogen or fluctuations in intramuscular metabolites, whereas central responses commonly refer to reductions in central motor drive elicited by alterations in blood glucose and neurotransmitter concentrations as well as arterial hypoxemia. Hypoxia may accelerate both peripheral and central pathways of fatigue, with the level of hypoxia strongly dictating the degree and primary locus of impairment. As more people journey to hypoxic settings for work and recreation, developing strategies to improve work capacity in these environments becomes increasingly relevant. Given that sea level performance improves with nutritional interventions such as carbohydrate (CHO) ingestion, a similar strategy may prove effective in delaying fatigue in hypoxia, particularly considering how the metabolic pathways enhanced with CHO supplementation overlap the fatiguing pathways upregulated in hypoxia. Many questions regarding the relationship between CHO, hypoxia, and fatigue remain unanswered, including specifics on when to ingest, what to ingest, and how varying altitudes influence supplementation effectiveness. Therefore, the purpose of this narrative review is to examine the peripheral and central mechanisms contributing to fatigue during aerobic exercise at varying degrees of hypoxia and to assess the role of CHO ingestion in attenuating fatigue onset.
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Affiliation(s)
- Hunter L Paris
- Department of Sports Medicine, Pepperdine University, Malibu, CA, USA
| | - Erin C Sinai
- Department of Sports Medicine, Pepperdine University, Malibu, CA, USA
| | - Ren-Jay Shei
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, and Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Timothy D Mickleborough
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN, USA
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Spatenkova V, Bednar R, Oravcova G, Melichova A, Kuriscak E. Yogic breathing in hypobaric environment: breathing exercising and its effect on hypobaric hypoxemia and heart rate at 3,650-m elevation. J Exerc Rehabil 2021; 17:270-278. [PMID: 34527639 PMCID: PMC8413908 DOI: 10.12965/jer.2142324.162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/01/2021] [Indexed: 11/22/2022] Open
Abstract
High altitude sojourn is a risk factor for hypobaric hypoxemia and subsequent altitude sickness. The aim of this study was to analyze the effect of new type of yogic breathing—Maheshwarananda’s new Modified Bhujangini Pranayama performed by active yoga practitioners—on the arterial haemoglobin saturation of oxygen (measured by the pulse oximetry - SpO2) and the heart rate compared to normal spontaneous resting breathing. A pilot prospective study was conducted in the Himalayas at an altitude of 3,650 m. We monitored SpO2 and pulse rate in 34 experienced yoga practitioners. Within the 3 measurement days at the altitude of 3,650 m, the mean value of SpO2 increased from 89.11± 4.78 to 93.26±4.44 (P<0.001) after the yogic breathing exercise. No significant changes were observed in pulse rate (P<0.230) measured before and after yogic breathing. The new Yogic breathing—Maheshwarananda’s Modified Bhujangini Pranayama—is increasing the arterial haemoglobin saturation compared to normal resting spontaneous breathing. The heart rate was not affected by this type of yogic breathing.
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Affiliation(s)
- Vera Spatenkova
- Faculty of Health Studies, Technical University of Liberec, Liberec, Czech Republic.,Neurointensive Care Unit, Neurocenter, Regional Hospital, Liberec, Czech Republic.,Institute of Physiology, First Medical Faculty, Charles University in Prague, Praha, Czech Republic
| | - Roman Bednar
- Department of Physiotherapy Balneology and Medical Rehabilitation, University Hospital with Polyclinic of F. D. Roosevelt, Banska Bystrica, Slovakia Republic
| | - Gabriela Oravcova
- Clinic of Pneumology and Phtiseology, Martin University Hospital, Martin, Slovakia Republic
| | - Anna Melichova
- Faculty of Health Care, Banska Bystrica, Slovak Medical University, Banska Bystrica, Slovakia Republic
| | - Eduard Kuriscak
- Institute of Physiology, First Medical Faculty, Charles University in Prague, Praha, Czech Republic
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41
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Kelly LP, Basset FA, McCarthy J, Ploughman M. Normobaric Hypoxia Exposure During Treadmill Aerobic Exercise After Stroke: A Safety and Feasibility Study. Front Physiol 2021; 12:702439. [PMID: 34483958 PMCID: PMC8415265 DOI: 10.3389/fphys.2021.702439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/30/2021] [Indexed: 11/23/2022] Open
Abstract
Objective To evaluate the safety and feasibility of performing treadmill aerobic exercise in moderate normobaric hypoxia among chronic hemiparetic stroke survivors. Design Observational study using convenience sampling. Setting Research laboratory in a tertiary rehabilitation hospital. Participants Chronic hemiparetic stroke survivors who could walk at least 10-m with or without assistance and had no absolute contraindications to exercise testing. Intervention Participants (three male and four female) were asked to complete three normobaric hypoxia exposure protocols within a single session. First, they were passively exposed to normobaric hypoxia through gradual reductions in the fraction of inspired oxygen (FIO2 = 20.9, 17.0, and 15.0%) while seated (5-min at each level of FIO2). Participants were then exposed to the same reductions in FIO2 during constant-load exercise performed on a treadmill at 40% of heart rate reserve. Finally, participants completed 20-min of exercise while intermittently exposed to moderate normobaric hypoxia (5 × 2-min at FIO2 = 15.0%) interspaced with 2-min normoxia intervals (FIO2 = 20.9%). Outcome Measures The primary outcome was occurrence of adverse events, which included standardized criteria for terminating exercise testing, blood oxygen saturation (SpO2) <80%, or acute mountain sickness score >2. The increased cardiovascular strain imposed by normobaric hypoxia exposure at rest and during exercise was evaluated by changes in SpO2, heart rate (HR), blood pressure, and rating of perceived exertion (RPE). Results One participant reported mild symptoms of nausea during exercise in normobaric hypoxia and discontinued participation. No other adverse events were recorded. Intermittent normobaric hypoxia exposure was associated with reduced SpO2 (MD = −7.4%, CI: −9.8 to −5.0) and increased HR (MD = 8.2, CI: 4.6 to 11.7) compared to intervals while breathing typical room air throughout the 20-min constant-load exercise period. The increase in HR was associated with a 10% increase in relative effort. However, reducing FIO2 had little effect on blood pressure and RPE measurements. Conclusion Moderate normobaric hypoxia appeared to be a safe and feasible method to increase the cardiovascular strain of submaximal exercise in chronic hemiparetic stroke survivors. Future studies evaluating the effects of pairing normobaric hypoxia exposure with existing therapies on secondary prevention and functional recovery are warranted.
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Affiliation(s)
- Liam P Kelly
- Recovery and Performance Laboratory, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada.,School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Fabien Andre Basset
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Jason McCarthy
- Recovery and Performance Laboratory, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Michelle Ploughman
- Recovery and Performance Laboratory, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
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Breenfeldt Andersen A, Bonne TC, Bejder J, Jung G, Ganz T, Nemeth E, Olsen NV, Huertas JR, Nordsborg NB. Effects of altitude and recombinant human erythropoietin on iron metabolism: a randomized controlled trial. Am J Physiol Regul Integr Comp Physiol 2021; 321:R152-R161. [PMID: 34160288 DOI: 10.1152/ajpregu.00070.2021] [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] [Indexed: 11/22/2022]
Abstract
Current markers of iron deficiency (ID), such as ferritin and hemoglobin, have shortcomings, and hepcidin and erythroferrone (ERFE) could be of clinical relevance in relation to early assessment of ID. Here, we evaluate whether exposure to altitude-induced hypoxia (2,320 m) alone, or in combination with recombinant human erythropoietin (rHuEPO) treatment, affects hepcidin and ERFE levels before alterations in routine ID biomarkers and stress erythropoiesis manifest. Two interventions were completed, each comprising a 4-wk baseline, a 4-wk intervention at either sea level or altitude, and a 4-wk follow-up. Participants (n = 39) were randomly assigned to 20 IU·kg body wt-1 rHuEPO or placebo injections every second day for 3 wk during the two intervention periods. Venous blood was collected weekly. Altitude increased ERFE (P ≤ 0.001) with no changes in hepcidin or routine iron biomarkers, making ERFE of clinical relevance as an early marker of moderate hypoxia. rHuEPO treatment at sea level induced a similar pattern of changes in ERFE (P < 0.05) and hepcidin levels (P < 0.05), demonstrating the impact of accelerated erythropoiesis and not of other hypoxia-induced mechanisms. Compared with altitude alone, concurrent rHuEPO treatment and altitude exposure induced additive changes in hepcidin (P < 0.05) and ERFE (P ≤ 0.001) parallel with increases in hematocrit (P < 0.001), demonstrating a relevant range of both hepcidin and ERFE. A poor but significant correlation between hepcidin and ERFE was found (R2 = 0.13, P < 0.001). The findings demonstrate that hepcidin and ERFE are more rapid biomarkers of changes in iron demands than routine iron markers. Finally, ERFE and hepcidin may be sensitive markers in an antidoping context.
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Affiliation(s)
| | - Thomas C Bonne
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Bejder
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Grace Jung
- Department of Medicine and Pathology, Center for Iron Disorders, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Tomas Ganz
- Department of Medicine and Pathology, Center for Iron Disorders, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Elizabeta Nemeth
- Department of Medicine and Pathology, Center for Iron Disorders, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Niels Vidiendal Olsen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Jesús Rodríguez Huertas
- Department of Physiology, Faculty of Sport Sciences, Institute of Nutrition and Food Technology, Biomedical Research Centre, University of Granada, Armilla, Spain
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Schüttler D, Weckbach LT, Hamm W, Maier F, Kassem S, Schier J, Lackermair K, Brunner S. Effect of acute altitude exposure on ventilatory thresholds in recreational athletes. Respir Physiol Neurobiol 2021; 293:103723. [PMID: 34171484 DOI: 10.1016/j.resp.2021.103723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 06/01/2021] [Accepted: 06/18/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE High altitude (HA) training is frequently used in endurance sports and recreational athletes increasingly participate in cross mountain competitions. At high altitude aerobic physiology changes profoundly. Ventilatory thresholds (VTs) are measures for endurance performance but the impact of exposure to acute altitude (AA) on VTs in recreational athletes has been insufficiently explored to date and most studies investigated effects under normobaric hypoxia. METHODS In this cross-sectional study we investigated the effects of AA exposure at 2650 m/715 mbar on anerobic threshold (VT1) and respiratory compensation point (VT2) in a graded cycling test in 14 recreational athletes (4 female, 10 male) compared to baseline levels (521 m, 949 mbar). RESULTS At VT1, a decline in power output (PO) from median 115.5 W to 105.0 W (median -12.3 %, p = 0.032; Wilcoxon test) during exposure to HA was observed. VO2/body weight and VO2/heart rate decreased markedly (- 9.5 %, p = 0.016; -10.5 %, p = 0.012). At VT2 we found a significant decline of PO from 184.5-170.5 W (-13.1 %, p = 0.0014), of VO2/body weight and of VO2/heart rate (-10.1 %, p = 0.0015; -8.7 %, p = 0.002) compared to baseline values. Absolute VO2 decreased (-9.5 %, p = 0.0014 and -10.1 %, p = 0.0002) while minute ventilation and heart rates remained unchanged at both thresholds. CONCLUSION Our data allows a quantification of performance loss at HA in recreational athletes and demonstrates that VT-guided training intensities and workloads need to be adapted for training at HA.
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Affiliation(s)
- Dominik Schüttler
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany; Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Ludwig T Weckbach
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany; Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Munich, Germany; Institute of Cardiovascular Physiology and Pathophysiology, Biomedical Center, LMU Munich, Planegg-Martinsried, Germany
| | - Wolfgang Hamm
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Florian Maier
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Sari Kassem
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Johannes Schier
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Korbinian Lackermair
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Stefan Brunner
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany.
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Martini D, Dussex N, Robertson BC, Gemmell NJ, Knapp M. Evolution of the "world's only alpine parrot": Genomic adaptation or phenotypic plasticity, behaviour and ecology? Mol Ecol 2021; 30:6370-6386. [PMID: 33973288 DOI: 10.1111/mec.15978] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 04/19/2021] [Accepted: 04/28/2021] [Indexed: 02/06/2023]
Abstract
Climate warming, in particular in island environments, where opportunities for species to disperse are limited, may become a serious threat to cold adapted alpine species. In order to understand how alpine species may respond to a warming world, we need to understand the drivers that have shaped their habitat specialisation and the evolutionary adaptations that allow them to utilize alpine habitats. The endemic, endangered New Zealand kea (Nestor notabilis) is considered the only alpine parrot in the world. As a species commonly found in the alpine zone it may be highly susceptible to climate warming. But is it a true alpine specialist? Is its evolution driven by adaptation to the alpine zone, or is the kea an open habitat generalist that simply uses the alpine zone to, for example, avoid lower lying anthropogenic landscapes? We use whole genome data of the kea and its close, forest adapted sister species, the kākā (Nestor meridionalis) to reconstruct the evolutionary history of both species and identify the functional genomic differences that underlie their habitat specialisations. Our analyses do not identify major functional genomic differences between kea and kākā in pathways associated with high-altitude. Rather, we found evidence that selective pressures on adaptations commonly found in alpine species are present in both Nestor species, suggesting that selection for alpine adaptations has not driven their divergence. Strongly divergent demographic responses to past climate warming between the species nevertheless highlight potential future threats to kea survival in a warming world.
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Affiliation(s)
- Denise Martini
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Nicolas Dussex
- Centre for Palaeogenetics, Stockholm, Sweden.,Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden.,Department of Zoology, Stockholm University, Stockholm, Sweden
| | | | - Neil J Gemmell
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Michael Knapp
- Department of Anatomy, University of Otago, Dunedin, New Zealand
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Roi GS. Fatal Events Related to Running Competitions in the Mountains. Wilderness Environ Med 2021; 32:176-180. [PMID: 33744107 DOI: 10.1016/j.wem.2020.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 11/08/2020] [Accepted: 12/08/2020] [Indexed: 11/16/2022]
Abstract
INTRODUCTION The few epidemiologic studies published previously about different forms of mountain running (ie, fell running, sky running, and ultratrail running) have not reported on fatal events. This report aims to contribute to the literature on mountain running fatalities, recording and classifying fatal events related to mountain running competitions found in online literature searches over a 12-y period. METHODS From 2008 to 2019, searches on mountain sport, mountain races, and newspaper websites were periodically performed, looking for fatal events related to running competitions in the mountains. Data are presented as mean±SD or percentage, as appropriate. RESULTS Fifty-one fatal events, involving 45 men (88%) and 6 women (12%), aged 50±11 and 46±6 y, respectively, were recorded in the 2008 to 2019 period in Western Europe. These events occurred during races (n=35; 69%), during training (n=13; 25%), and after races (n=3; 6%); 43% were sudden cardiac death, 32% due to falls (blunt trauma), 16% due to hypothermia, 4% due to both blunt trauma and hypothermia, 4% due to lightning strike injuries, and 2% due to animal attack (injuries from deer). CONCLUSIONS Understanding all of the causes of fatal events is necessary to institute preventative efforts and to organize rescues. Preventative efforts should be implemented by race organizers and by athletes themselves, and rescue teams can be trained and equipped to address all of these possible events. The relatively high percentage of sudden cardiac deaths stresses the need for preparticipation cardiovascular screenings. Further longitudinal studies are necessary to better understand the real impact of fatal events on the mountain running population.
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Affiliation(s)
- Giulio Sergio Roi
- Education and Research Department, Isokinetic Medical Group, Bologna, Italy; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
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Lodin-Sundström A, Holmström P, Ekstam M, Söderberg D, Schagatay E. Splenic contraction is enhanced by exercise at simulated high altitude. Eur J Appl Physiol 2021; 121:1725-1732. [PMID: 33683439 PMCID: PMC8144132 DOI: 10.1007/s00421-021-04637-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 02/09/2021] [Indexed: 11/30/2022]
Abstract
Purpose Splenic contraction increases circulating hemoglobin (Hb) with advantages during hypoxia. As both hypoxia and exercise have been shown to be important separate triggers of splenic contraction we aimed to investigate if the spleen response to simulated high altitude (HA) is enhanced by superimposing exercise. Method Fourteen healthy volunteers (seven females) performed the following protocol in a normobaric environment sitting on an ergometer cycle: 20 min rest in normoxia; 20 min rest while breathing hypoxic gas simulating an altitude of 3500 m; 10 min exercise at an individually set intensity while breathing the hypoxic gas; 20 min rest in hypoxia; and finally 20 min rest in normoxia. Spleen measurements were collected by ultrasonic imaging and venous Hb measured at the end of each intervention. Result Mean ± SD baseline spleen volume during normoxic rest was 280 ± 107 mL, the volume was reduced by 22% during rest in hypoxia to 217 ± 92 mL (p < 0.001) and by 33% during exercise in hypoxia (189 mL; p < 0.001). Hb was 140.7 ± 7.0 g/L during normoxic rest and 141.3 ± 7.4 g/L during hypoxic rest (NS), but increased by 5.3% during hypoxic exercise (148.6 ± 6.3 g/L; p < 0.001). Spleen volume and Hb were stepwise changed back to baseline at cessation of exercise and return to normoxia. Conclusion Splenic contraction is induced by hypoxia and further enhanced by superimposing exercise, and reduced when exercise ceases, in a step-wise manner, showing that the tonic but partial contraction observed in long-term field expeditions to HA may occur also in the short term. This “graded response” may be beneficial during acclimatization to HA, to cope with moderate chronic hypoxia during rest while allowing additional enhancement of oxygen carrying capacity to overcome short bouts of extreme hypoxia caused by exercise.
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Affiliation(s)
- Angelica Lodin-Sundström
- Department of Health Sciences, Mid Sweden University, Östersund, Sweden. .,Environmental Physiology Group, Department of Nursing Science, Mid Sweden University, Holmgatan 10, 85170, Sundsvall, Sweden.
| | - Pontus Holmström
- Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | - Marcus Ekstam
- Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | - Daniel Söderberg
- Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | - Erika Schagatay
- Department of Health Sciences, Mid Sweden University, Östersund, Sweden.,Swedish Winter Sports Research Centre, Östersund, Sweden
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Verma RK, Kalyakulina A, Giuliani C, Shinde P, Kachhvah AD, Ivanchenko M, Jalan S. Analysis of human mitochondrial genome co-occurrence networks of Asian population at varying altitudes. Sci Rep 2021; 11:133. [PMID: 33420243 PMCID: PMC7794584 DOI: 10.1038/s41598-020-80271-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 12/16/2020] [Indexed: 12/13/2022] Open
Abstract
Networks have been established as an extremely powerful framework to understand and predict the behavior of many large-scale complex systems. We studied network motifs, the basic structural elements of networks, to describe the possible role of co-occurrence of genomic variations behind high altitude adaptation in the Asian human population. Mitochondrial DNA (mtDNA) variations have been acclaimed as one of the key players in understanding the biological mechanisms behind adaptation to extreme conditions. To explore the cumulative effects of variations in the mitochondrial genome with the variation in the altitude, we investigated human mt-DNA sequences from the NCBI database at different altitudes under the co-occurrence motifs framework. Analysis of the co-occurrence motifs using similarity clustering revealed a clear distinction between lower and higher altitude regions. In addition, the previously known high altitude markers 3394 and 7697 (which are definitive sites of haplogroup M9a1a1c1b) were found to co-occur within their own gene complexes indicating the impact of intra-genic constraint on co-evolution of nucleotides. Furthermore, an ancestral 'RSRS50' variant 10,398 was found to co-occur only at higher altitudes supporting the fact that a separate route of colonization at these altitudes might have taken place. Overall, our analysis revealed the presence of co-occurrence interactions specific to high altitude at a whole mitochondrial genome level. This study, combined with the classical haplogroups analysis is useful in understanding the role of co-occurrence of mitochondrial variations in high altitude adaptation.
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Affiliation(s)
- Rahul K Verma
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore, 453552, India
| | - Alena Kalyakulina
- Department of Applied Mathematics and Centre of Bioinformatics, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Cristina Giuliani
- Laboratory of Molecular Anthropology & Center for Genome Biology, Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Pramod Shinde
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, 92037, USA
| | - Ajay Deep Kachhvah
- Complex Systems Lab, Department of Physics, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore, 453552, India
| | - Mikhail Ivanchenko
- Department of Applied Mathematics and Centre of Bioinformatics, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.,Laboratory of Systems Medicine of Healthy Aging and Department of Applied Mathematics, Lobachevsky University, Nizhny Novgorod, Russia
| | - Sarika Jalan
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore, 453552, India. .,Complex Systems Lab, Department of Physics, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore, 453552, India. .,Laboratory of Systems Medicine of Healthy Aging and Department of Applied Mathematics, Lobachevsky University, Nizhny Novgorod, Russia. .,Center for Theoretical Physics of Complex Systems, Institute for Basic Science (IBS), Daejeon, 34126, Republic of Korea.
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Koivisto-Mørk AE, Paur I, Paulsen G, Garthe I, Raastad T, Bastani NE, Blomhoff R, Bøhn SK. Dietary Adjustments to Altitude Training in Elite Endurance Athletes; Impact of a Randomized Clinical Trial With Antioxidant-Rich Foods. Front Sports Act Living 2020; 2:106. [PMID: 33345095 PMCID: PMC7739752 DOI: 10.3389/fspor.2020.00106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/14/2020] [Indexed: 11/13/2022] Open
Abstract
Background: Altitude training stresses several physiological and metabolic processes and alters the dietary needs of the athletes. International Olympic Committee (IOC)'s Nutrition Expert Group suggests that athletes should increase intake of energy, carbohydrate, iron, fluid, and antioxidant-rich foods while training at altitude. Objective: We investigated whether athletes adjust their dietary intake according to the IOC's altitude-specific dietary recommendations, and whether an in-between meal intervention with antioxidant-rich foods altered the athletes' dietary composition and nutrition-related blood parameters (mineral, vitamin, carotenoid, and hormone concentrations). Design: The dietary adjustments to altitude training (3 weeks at 2,320 m) were determined for 31 elite endurance athletes (23 ± 5 years, 23 males, 8 females) by six interviewer-administered 24-h dietary recalls on non-consecutive days; three before and during the altitude camp. The additional effect of in -between meal intervention with eucaloric antioxidant-rich or control snacks (1,000 kcal/day) was tested in a randomized controlled trial with parallel design. Results: At altitude the athletes increased their energy intake by 35% (1,430 ± 630 kcal/day, p < 0.001), the provided snacks accounting for 70% of this increase. Carbohydrate intake increased from 6.5 ± 1.8 g/kg body weight (BW) (50 E%) to 9.3 ± 2.1 g/kg BW (53 E%) (p < 0.001), with no difference between the antioxidant and control group. Dietary iron, fluid, and antioxidant-rich food intake increased by 37, 38, and 104%, respectively, in the whole cohort. The intervention group had larger increases in polyunsaturated fatty acids (PUFA), ω3 PUFA (n-3 fatty acids), ω6 PUFA (n-6 fatty acids), fiber, vitamin C, folic acid, and copper intake, while protein intake increased more among the controls, reflecting the nutritional content of the snacks. Changes in the measured blood minerals, vitamins, and hormones were not differentially affected by the intervention except for the carotenoid; zeaxanthin, which increased more in the intervention group (p < 0.001). Conclusions: Experienced elite endurance athletes increased their daily energy, carbohydrate, iron, fluid, and antioxidant-rich food intake during a 3-week training camp at moderate altitude meeting most of the altitude-specific dietary recommendations. The intervention with antioxidant-rich snacks improved the composition of the athletes' diets but had minimal impact on the measured nutrition-related blood parameters. Clinical Trial Registry Number: NCT03088891 (www.clinicaltrials.gov), Norwegian registry number: 626539 (https://rekportalen.no/).
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Affiliation(s)
- Anu E Koivisto-Mørk
- Norwegian Olympic Sports Centre, Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway
| | - Ingvild Paur
- Norwegian National Advisory Unit on Disease-Related Undernutrition, Oslo University Hospital, Oslo, Norway
| | - Gøran Paulsen
- Norwegian Olympic Sports Centre, Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway.,Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Ina Garthe
- Norwegian Olympic Sports Centre, Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway
| | - Truls Raastad
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Nasser E Bastani
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Rune Blomhoff
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Division of Cancer Medicine, Oslo University Hospital, Oslo, Norway
| | - Siv K Bøhn
- Faculty of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences, Ås, Norway
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Schlittler M, Gatterer H, Turner R, Regli IB, Woyke S, Strapazzon G, Rasmussen P, Kob M, Mueller T, Goetze JP, Maillard M, van Hall G, Feraille E, Siebenmann C. Regulation of plasma volume in male lowlanders during 4 days of exposure to hypobaric hypoxia equivalent to 3500 m altitude. J Physiol 2020; 599:1083-1096. [PMID: 33124686 PMCID: PMC7894546 DOI: 10.1113/jp280601] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/27/2020] [Indexed: 12/16/2022] Open
Abstract
Key points Acclimatization to hypoxia leads to a reduction in plasma volume (PV) that restores arterial O2 content. Findings from studies investigating the mechanisms underlying this PV contraction have been controversial, possibly as experimental conditions were inadequately controlled. We examined the mechanisms underlying the PV contraction evoked by 4 days of exposure to hypobaric hypoxia (HH) in 11 healthy lowlanders, while strictly controlling water intake, diet, temperature and physical activity. Exposure to HH‐induced an ∼10% PV contraction that was accompanied by a reduction in total circulating protein mass, whereas diuretic fluid loss and total body water remained unchanged. Our data support an oncotically driven fluid redistribution from the intra‐ to the extravascular space, rather than fluid loss, as the mechanism underlying HH‐induced PV contraction.
Abstract Extended hypoxic exposure reduces plasma volume (PV). The mechanisms underlying this effect are controversial, possibly as previous studies have been confounded by inconsistent experimental conditions. Here, we investigated the effect of hypobaric hypoxia (HH) on PV in a cross‐over study that strictly controlled for diet, water intake, physical activity and temperature. Eleven males completed two 4‐day sojourns in a hypobaric chamber, one in normoxia (NX) and one in HH equivalent to 3500 m altitude. PV, urine output, volume‐regulating hormones and plasma protein concentration were determined daily. Total body water (TBW) was determined at the end of both sojourns by deuterium dilution. Although PV was 8.1 ± 5.8% lower in HH than in NX after 24 h and remained ∼10% lower thereafter (all P < 0.002), no differences were detected in TBW (P = 0.17) or in 24 h urine volumes (all P > 0.23). Plasma renin activity and circulating aldosterone were suppressed in HH during the first half of the sojourn (all P < 0.05) but thereafter similar to NX, whereas no differences were detected for copeptin between sojourns (all P > 0.05). Markers for atrial natriuretic peptide were higher in HH than NX after 30 min (P = 0.001) but lower during the last 2 days (P < 0.001). While plasma protein concentration was similar between sojourns, total circulating protein mass (TCP) was reduced in HH at the same time points as PV (all P < 0.03). Despite transient hormonal changes favouring increased diuresis, HH did not enhance urine output. Instead, the maintained TBW and reduced TCP support an oncotically driven fluid redistribution into the extravascular compartment as the mechanism underlying PV contraction. Acclimatization to hypoxia leads to a reduction in plasma volume (PV) that restores arterial O2 content. Findings from studies investigating the mechanisms underlying this PV contraction have been controversial, possibly as experimental conditions were inadequately controlled. We examined the mechanisms underlying the PV contraction evoked by 4 days of exposure to hypobaric hypoxia (HH) in 11 healthy lowlanders, while strictly controlling water intake, diet, temperature and physical activity. Exposure to HH‐induced an ∼10% PV contraction that was accompanied by a reduction in total circulating protein mass, whereas diuretic fluid loss and total body water remained unchanged. Our data support an oncotically driven fluid redistribution from the intra‐ to the extravascular space, rather than fluid loss, as the mechanism underlying HH‐induced PV contraction.
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Affiliation(s)
- Maja Schlittler
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Hannes Gatterer
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Rachel Turner
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Ivo B Regli
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy.,Department of Anesthesia and Intensive Care Medicine, 'F. Tappeiner' Hospital, Merano, Italy
| | - Simon Woyke
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy.,Department of Anaesthesiology and Intensive Care Medicine, Medical University of Innsbruck, Austria
| | - Giacomo Strapazzon
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | | | - Michael Kob
- Division of Clinical Nutrition, Bolzano Regional Hospital, Bolzano, Italy
| | - Thomas Mueller
- Department of Clinical Pathology, Hospital of Bolzano, Bolzano, Italy
| | - Jens P Goetze
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Marc Maillard
- Service of Nephrology, University Hospital of Lausanne, Lausanne, Switzerland
| | - Gerrit van Hall
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Clinical Metabolomics Core Facility, Rigshospitalet, University of Copenhagen, Denmark
| | - Eric Feraille
- National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland.,Department of Cellular Physiology and Metabolism, University of Geneva University Medical Center, Geneva, Switzerland
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50
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Holmström PK, Bird JD, Thrall SF, Kalker A, Herrington BA, Soriano JE, Mann LM, Rampuri ZH, Brutsaert TD, Karlsson Ø, Sherpa MT, Schagatay EKA, Day TA. The effects of high altitude ascent on splenic contraction and the diving response during voluntary apnoea. Exp Physiol 2020; 106:160-174. [DOI: 10.1113/ep088571] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 09/03/2020] [Indexed: 12/30/2022]
Affiliation(s)
| | - Jordan D. Bird
- Department of Biology Faculty of Science and Technology Mount Royal University Calgary Alberta Canada
| | - Scott F. Thrall
- Department of Biology Faculty of Science and Technology Mount Royal University Calgary Alberta Canada
| | - Ann Kalker
- Department of Biology Faculty of Science and Technology Mount Royal University Calgary Alberta Canada
- Radboud University Nijmegen Netherlands
| | - Brittney A. Herrington
- Department of Biology Faculty of Science and Technology Mount Royal University Calgary Alberta Canada
| | - Jan E. Soriano
- Department of Biology Faculty of Science and Technology Mount Royal University Calgary Alberta Canada
| | - Leah M. Mann
- Department of Biology Faculty of Science and Technology Mount Royal University Calgary Alberta Canada
| | - Zahrah H. Rampuri
- Department of Biology Faculty of Science and Technology Mount Royal University Calgary Alberta Canada
| | - Tom D. Brutsaert
- Department of Exercise Science Syracuse University Syracuse NY USA
| | - Øyvind Karlsson
- Swedish Winter Sports Research Centre Mid Sweden University Östersund Sweden
| | | | - Erika K. A. Schagatay
- Department of Health Sciences Mid Sweden University Östersund Sweden
- Swedish Winter Sports Research Centre Mid Sweden University Östersund Sweden
| | - Trevor A. Day
- Department of Biology Faculty of Science and Technology Mount Royal University Calgary Alberta Canada
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