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Kanaoka T, Tran K, Lee W. Discrepant home sleep apnea tests and discrepant CPAP downloads: a tale of two altitudes. J Clin Sleep Med 2024; 20:323-325. [PMID: 37889161 PMCID: PMC10835770 DOI: 10.5664/jcsm.10894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 10/26/2023] [Accepted: 10/26/2023] [Indexed: 10/28/2023]
Affiliation(s)
| | - Katie Tran
- University of Texas Southwestern, Dallas, Texas
| | - Won Lee
- University of Texas Southwestern, Dallas, Texas
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2
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Niclou A, Sarma M, Levy S, Ocobock C. To the extreme! How biological anthropology can inform exercise physiology in extreme environments. Comp Biochem Physiol A Mol Integr Physiol 2023; 284:111476. [PMID: 37423419 DOI: 10.1016/j.cbpa.2023.111476] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/11/2023]
Abstract
The fields of biological anthropology and exercise physiology are closely related and can provide mutually beneficial insights into human performance. These fields often use similar methods and are both interested in how humans function, perform, and respond in extreme environments. However, these two fields have different perspectives, ask different questions, and work within different theoretical frameworks and timescales. Biological anthropologists and exercise physiologists can greatly benefit from working together when examining human adaptation, acclimatization, and athletic performance in the extremes of heat, cold, and high-altitude. Here we review the adaptations and acclimatizations in these three different extreme environments. We then examine how this work has informed and built upon exercise physiology research on human performance. Finally, we present an agenda for moving forward, hopefully, with these two fields working more closely together to produce innovative research that improves our holistic understanding of human performance capacities informed by evolutionary theory, modern human acclimatization, and the desire to produce immediate and direct benefits.
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Affiliation(s)
- Alexandra Niclou
- Pennington Biomedical Research Center, Baton Rouge, LA, United States of America. https://twitter.com/fiat_luxandra
| | - Mallika Sarma
- Human Space Flight Lab, Johns Hopkins School of Medicine, Baltimore, MD, United States of America. https://twitter.com/skyy_mal
| | - Stephanie Levy
- Department of Anthropology, CUNY Hunter College, New York, NY, United States of America; New York Consortium in Evolutionary Primatology, New York, NY, United States of America. https://twitter.com/slevyscience
| | - Cara Ocobock
- University of Notre Dame Department of Anthropology, Notre Dame, IN, United States of America; Eck Institute for Global Health, Institute for Educational Initiatives, University of Notre Dame, United States of America.
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3
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Rytz CL, Pun M, Mawhinney JA, Mounsey CA, Mura M, Martin A, Pialoux V, Hartmann SE, Furian M, Rawling JM, Lopez I, Soza D, Moraga FA, Lichtblau M, Bader PR, Ulrich S, Bloch KE, Frise MC, Poulin MJ. Differential Effects of High-Altitude Exposure on Markers of Oxidative Stress, Antioxidant Capacity and Iron Profiles. Am J Physiol Regul Integr Comp Physiol 2022; 323:R445-R456. [PMID: 35938686 DOI: 10.1152/ajpregu.00321.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
High altitude (HA) exposure may stimulate significant physiological and molecular changes, resulting in HA-related illnesses. HA may impact oxidative stress, antioxidant capacity and iron homeostasis, yet it is unclear how both repeated exposure and HA acclimatization may modulate such effects. Therefore, we assessed the effects of weeklong repeated daily HA exposure (2,900m to 5,050m) in altitude-naïve individuals (n=21, 13 females, mean ± SD, 25.3 ± 3.7 years) to mirror the working schedule of HA workers (n=19, all males, 40.1 ± 2.1 years) at the Atacama Large Millimeter Array (ALMA) Observatory (San Pedro de Atacama, Chile). Markers of oxidative stress, antioxidant capacity and iron homeostasis were measured in blood plasma. Levels of protein oxidation (p<0.001) and catalase activity (p=0.023) increased and serum iron (p<0.001), serum ferritin (p<0.001) and transferrin saturation (p<0.001) levels decreased with HA exposure in both groups. HA workers had lower levels of oxidative stress, and higher levels of antioxidant capacity, iron supply and hemoglobin concentration as compared to altitude-naïve individuals. Upon a second week of daily HA exposure, changes in levels of protein oxidation, glutathione peroxidase and nitric oxide metabolites were lower as compared to the first week in altitude-naïve individuals. These results indicate that repeated exposure to HA may significantly alter oxidative stress and iron homeostasis, and the degree of such changes may be dependent on if HA is visited naïvely or routinely. Further studies are required to fully elucidate differences in HA-induced changes in oxidative stress and iron homeostasis profiles amongst visitors of HA.
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Affiliation(s)
- Chantal L Rytz
- Libin Cardiovascular Institute, Calgary, Canada.,Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Matiram Pun
- Cumming School of Medicine, University of Calgary, Calgary, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
| | - Jamie A Mawhinney
- Department of Plastic Surgery, Queen Alexandra Hospital, Portsmouth University Hospital NHS Foundation Trust, UK
| | | | - Mathilde Mura
- Univ Lyon, University Lyon 1, Team "Atherosclerosis, Thrombosis and Physical Activity", Lyon, France
| | - Agnès Martin
- Univ Lyon, University Lyon 1, Team "Atherosclerosis, Thrombosis and Physical Activity", Lyon, France
| | - Vincent Pialoux
- Univ Lyon, University Lyon 1, Team "Atherosclerosis, Thrombosis and Physical Activity", Lyon, France
| | - Sara E Hartmann
- Cumming School of Medicine, University of Calgary, Calgary, Canada.,Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
| | - Michael Furian
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Jean M Rawling
- Department of Family Medicine at the University of Calgary, Calgary, Canada
| | - Ivan Lopez
- Safety Group, Atacama Large Millimeter Submillimeter Array, Calama, Chile
| | - Daniel Soza
- Safety Group, Atacama Large Millimeter Submillimeter Array, Calama, Chile
| | - Fernando A Moraga
- Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
| | - Mona Lichtblau
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Patrick R Bader
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Konrad E Bloch
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Matthew C Frise
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK; Intensive Care Unit, Royal Berkshire Hospitals NHS Foundation Trust, Reading, UK
| | - Marc J Poulin
- Libin Cardiovascular Institute, Calgary, Canada.,Cumming School of Medicine, University of Calgary, Calgary, Canada.,Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Canada.,Faculty of Kinesiology, University of Calgary, Calgary, Canada
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4
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Calderon-Jofre R, Moraga D, Moraga FA. The Effect of Chronic Intermittent Hypobaric Hypoxia on Sleep Quality and Melatonin Serum Levels in Chilean Miners. Front Physiol 2022; 12:809360. [PMID: 35222064 PMCID: PMC8864145 DOI: 10.3389/fphys.2021.809360] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 12/22/2021] [Indexed: 11/13/2022] Open
Abstract
High-altitude mining is an important economic resource for Chile. These workers are exposed to chronic intermittent hypobaric hypoxia (CIHH), which reduces their sleep quality and increases the risk of accidents and long-term illnesses. Melatonin, a hormone produced by the pineal gland, is a sleep inducer that regulates the circadian cycle and may be altered in populations subjected to CIHH. This work aimed to assess the relationship between altitude, sleep quality, and plasma melatonin concentrations in miners with CIHH exposure. 288 volunteers were recruited from five altitudes (0, 1,600, 2,500, 3,500, and 4,500 m). All volunteers worked for 7 days at altitude, followed by 7 days of rest at sea level. We performed anthropometric assessments, nocturnal oximetry, sleep quality and sleepiness surveys, and serum melatonin levels upon awakening. Although oxygen saturation progressively decreased and heart rate increased at higher altitudes, subjective perception of sleep quality was not significantly different, and sleepiness increased in all groups compared to population at sea level. Similarly, melatonin levels increased at all assessed altitudes compared to the population at sea level. These data confirm that sleep disturbances associated with CIHH increase morning melatonin levels. Therefore, this hormone and could potentially serve as a biomarker of sleep quality.
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Affiliation(s)
- Rodrigo Calderon-Jofre
- Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
| | - Daniel Moraga
- Departamento de Medicina, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, Chile
| | - Fernando A. Moraga
- Departamento de Medicina, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, Chile
- *Correspondence: Fernando A. Moraga,
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Lopez I, Aravena R, Soza D, Morales A, Riquelme S, Calderon-Jofré R, Moraga FA. Comparison Between Pressure Swing Adsorption and Liquid Oxygen Enrichment Techniques in the Atacama Large Millimeter/Submillimeter Array Facility at the Chajnantor Plateau (5,050 m). Front Physiol 2021; 12:775240. [PMID: 34955888 PMCID: PMC8692831 DOI: 10.3389/fphys.2021.775240] [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: 09/13/2021] [Accepted: 11/08/2021] [Indexed: 11/22/2022] Open
Abstract
The Chilean workforce has over 200,000 people that are intermittently exposed to altitudes over 4,000 m. In 2012, the Ministry of Health provided a technical guide for high-altitude workers that included a series of actions to mitigate the effects of hypoxia. Previous studies have shown the positive effect of oxygen enrichment at high altitudes. The Atacama Large Millimeter/submillimeter Array (ALMA) radiotelescope operates at 5,050 m [Array Operations Site (AOS)] and is the only place in the world where pressure swing adsorption (PSA) and liquid oxygen technologies have been installed at a large scale. These technologies reduce the equivalent altitude by increasing oxygen availability. This study aims to perform a retrospective comparison between the use of both technologies during operation in ALMA at 5,050 m. In each condition, variables such as oxygen (O2), temperature, and humidity were continuously recorded in each AOS rooms, and cardiorespiratory variables were registered. In addition, we compared portable O2 by using continuous or demand flow during outdoor activities at very high altitudes. The outcomes showed no differences between production procedures (PSA or liquid oxygen) in regulating oxygen availability at AOS facilities. As a result, big-scale installations have difficulties reaching the appropriate O2 concentration due to leaks in high mobility areas. In addition, the PSA plant requires adequacy and maintenance to operate at a very high altitude. A continuous flow of 2–3 l/min of portable O2 is recommended at 5,050 m.
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Affiliation(s)
- Ivan Lopez
- Atacama Large Millimeter/Submillimeter Array, San Pedro de Atacama, Chile
| | - Reinaldo Aravena
- Atacama Large Millimeter/Submillimeter Array, San Pedro de Atacama, Chile
| | - Daniel Soza
- Atacama Large Millimeter/Submillimeter Array, San Pedro de Atacama, Chile
| | - Alicia Morales
- Atacama Large Millimeter/Submillimeter Array, San Pedro de Atacama, Chile
| | - Silvia Riquelme
- Departamento de Medicina, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, Chile
| | - Rodrigo Calderon-Jofré
- Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
| | - Fernando A Moraga
- Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
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Cai J, Ruan J, Shao X, Ding Y, Xie K, Tang C, Yan Z, Luo E, Jing D. Oxygen Enrichment Mitigates High-Altitude Hypoxia-Induced Hippocampal Neurodegeneration and Memory Dysfunction Associated with Attenuated Tau Phosphorylation. High Alt Med Biol 2021; 22:274-284. [PMID: 34348049 DOI: 10.1089/ham.2020.0218] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cai, Jing, Junyong Ruan, Xi Shao, Yuanjun Ding, Kangning Xie, Chi Tang, Zedong Yan, Erping Luo, and Da Jing. Oxygen enrichment mitigates high-altitude hypoxia-induced hippocampal neurodegeneration and memory dysfunction associated with attenuated tau phosphorylation. High Alt Med Biol 00:000-000, 2021. Background: Brain is predominantly vulnerable to high-altitude hypoxia (HAH), resulting in neurodegeneration and cognitive impairment. The technology of oxygen enrichment has proven effective to decrease the heart rate and improve the arterial oxygen saturation by reducing the equivalent altitude. However, the efficacy of oxygen enrichment on HAH-induced cognitive impairments remains controversial based on the results of neuropsychological tests, and its role in HAH-induced hippocampal morphological and molecular changes remains unknown. Therefore, this study aims to systematically investigate the effects of oxygen enrichment on the memory dysfunction and hippocampal neurodegeneration caused by HAH. Materials and Methods: Fifty-one male Sprague-Dawley rats were equally assigned to three groups: normal control, HAH, and HAH with oxygen enrichment (HAHO). Rats in the HAH and HAHO groups were exposed to hypoxia for 3 days in a hypobaric hypoxia chamber at a simulated altitude of 6,000 m. Rats in the HAHO group were supplemented with oxygen-enriched air, with 12 hours/day in the hypobaric hypoxia chamber. Results: Our results showed that oxygen enrichment improved the locomotor activity of HAH-exposed rats. The Morris water maze test revealed that oxygen enrichment significantly ameliorated HAH-induced spatial memory deficits. Oxygen enrichment also improved morphological alterations of pyramidal cells and the ultrastructure of neurons in the hippocampal CA1 region in rats exposed to acute HAH. Tau hyperphosphorylation at Ser396, Ser262, Thr231, and Thr181 was also significantly attenuated by oxygen enrichment in HAH-exposed rats. Conclusions: Together, our study reveals that oxygen enrichment can ameliorate HAH-induced cognitive impairments associated with improved hippocampal morphology and molecular expression, and highlights that oxygen enrichment may become a promising alternative treatment against neurodegeneration for humans ascending to the plateau.
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Affiliation(s)
- Jing Cai
- Department of Clinical Diagnostics, College of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang, China.,Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Junyong Ruan
- Medical Engineering Department, Qingdao Special Servicemen Recuperation Center of PLA Navy, Qingdao, China
| | - Xi Shao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Yuanjun Ding
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Kangning Xie
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Chi Tang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Zedong Yan
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Da Jing
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
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Exercising in Hypoxia and Other Stimuli: Heart Rate Variability and Ventilatory Oscillations. Life (Basel) 2021; 11:life11070625. [PMID: 34203350 PMCID: PMC8306822 DOI: 10.3390/life11070625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/22/2021] [Accepted: 06/27/2021] [Indexed: 12/24/2022] Open
Abstract
Periodic breathing is a respiratory phenomenon frequently observed in patients with heart failure and in normal subjects sleeping at high altitude. However, until recently, periodic breathing has not been studied in wakefulness and during exercise. This review relates the latest findings describing this ventilatory disorder when a healthy subject is submitted to simultaneous physiological (exercise) and environmental (hypoxia, hyperoxia, hypercapnia) or pharmacological (acetazolamide) stimuli. Preliminary studies have unveiled fundamental physiological mechanisms related to the genesis of periodic breathing characterized by a shorter period than those observed in patients (11~12 vs. 30~60 s). A mathematical model of the respiratory system functioning under the aforementioned stressors corroborated these data and pointed out other parameters, such as dead space, later confirmed in further research protocols. Finally, a cardiorespiratory interdependence between ventilatory oscillations and heart rate variability in the low frequency band may partly explain the origin of the augmented sympathetic activation at exercise in hypoxia. These nonlinear instabilities highlight the intrinsic "homeodynamic" system that allows any living organism to adapt, to a certain extent, to permanent environmental and internal perturbations.
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8
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Richalet JP. [Adaption to chronic hypoxaemia by populations living at high altitude]. Rev Mal Respir 2021; 38:395-403. [PMID: 33541755 DOI: 10.1016/j.rmr.2020.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 10/13/2020] [Indexed: 12/14/2022]
Abstract
Permanent life at high altitude induces important physiological stresses linked to the exposure to chronic hypoxia. Various strategies have been adopted by diverse populations living in the Andes, Tibet or East Africa. The main mechanism is an increase in red blood cell production, more marked in Andeans than in Tibetans or Ethiopians. Other changes are observed in the cardiovascular or respiratory systems, as well as in the utero-placental circulation. Sometimes, a de-adaptation process to hypoxia develops, when erythrocytosis becomes excessive and leads to haematological, vascular and cerebral complications (Monge's disease or chronic mountain sickness). Pulmonary hypertension may also appear. Therapeutic options are available but not sufficiently used. Genetic studies have recently been undertaken to try to better understand the evolution of the human genome in populations living in various high altitude regions of the world, as well as the genetic risk factors for chronic diseases. A new model has appeared, intermittent chronic hypoxia, due to the development of economic activities (mainly mining) in desert regions of the Altiplano.
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Affiliation(s)
- J-P Richalet
- Laboratoire « Hypoxie & Poumon », UMR Inserm U1272, Université Sorbonne Paris Nord 13, 74, rue Marcel-Cachin, 93017 Bobigny cedex, France.
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Shao X, Dong X, Cai J, Tang C, Xie K, Yan Z, Luo E, Jing D. Oxygen Enrichment Ameliorates Cardiorespiratory Alterations Induced by Chronic High-Altitude Hypoxia in Rats. Front Physiol 2021; 11:616145. [PMID: 33488404 PMCID: PMC7817980 DOI: 10.3389/fphys.2020.616145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 12/07/2020] [Indexed: 12/23/2022] Open
Abstract
Chronic high-altitude hypoxia (HAH) results in compensatory pathological adaptations, especially in the cardiorespiratory system. The oxygen enrichment technology can provide long-lasting oxygen supply and minimize oxygen toxicity, which has proven to be effective to increase oxygen saturation, decrease heart rate, and improve human exercise performance after ascending to high altitudes. Nevertheless, it remains unknown whether oxygen enrichment can resist chronic HAH-induced cardiorespiratory alterations. Thirty-six male rats were equally assigned to the normal control (NC), HAH, and HAH with oxygen enrichment (HAHO) groups. The HAH and HAHO rats were housed in a hypobaric hypoxia chamber equivalent to 5,000 m for 4 weeks. The HAHO rats were exposed to oxygen-enriched air for 8 h/day. We found that oxygen enrichment mitigated the augmented skin blood flow and improved the locomotor activity of HAH-exposed rats. Oxygen enrichment inhibited HAH-induced increase in the production of red blood cells (RBCs). The hemodynamic results showed that oxygen enrichment decreased right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) in HAH-exposed rats. HAH-associated right ventricular hypertrophy and cardiomyocyte enlargement were ameliorated by oxygen enrichment. Oxygen enrichment inhibited HAH-induced excessive expression of cytokines associated with cardiac hypertrophy and myocardial fibrosis [angiotensin-converting enzyme (ACE)/angiotensin-converting enzyme 2 (ACE2), angiotensin II (Ang II), collagen type I alpha 1 (Col1α1), collagen type III alpha 1 (Col3α1), and hydroxyproline] in the right ventricle (RV). Oxygen enrichment inhibited medial thickening, stenosis and fibrosis of pulmonary arterioles, and cytokine expression related with fibrosis (Col1α1, Col3α1, and hydroxyproline) and pulmonary vasoconstriction [endothelin-1(ET-1)] in HAH-exposed rats. This study represents the first effort testing the efficacy of the oxygen enrichment technique on cardiopulmonary structure and function in chronic HAH animals, and we found oxygen enrichment has the capability of ameliorating chronic HAH-induced cardiopulmonary alterations.
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Affiliation(s)
- Xi Shao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Xu Dong
- Recuperation Management Office, Department of Medical Management and Training, Qingdao Special Service Recuperation Center of PLA Navy, Qingdao, China
| | - Jing Cai
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.,College of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Chi Tang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Kangning Xie
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Zedong Yan
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Da Jing
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
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10
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Aebi MR, Bourdillon N, Bron D, Millet GP. Minimal Influence of Hypobaria on Heart Rate Variability in Hypoxia and Normoxia. Front Physiol 2020; 11:1072. [PMID: 32973566 PMCID: PMC7472461 DOI: 10.3389/fphys.2020.01072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 08/04/2020] [Indexed: 11/24/2022] Open
Abstract
Introduction The present study evaluated the putative effect of hypobaria on resting HRV in normoxia and hypoxia. Methods Fifteen young pilot trainees were exposed to five different conditions in a randomized order: normobaric normoxia (NN, PB = 726 ± 5 mmHg, FIO2 = 20.9%), hypobaric normoxia (HN, PB = 380 ± 6 mmHg, FIO2≅40%), normobaric hypoxia (NH, PB = 725 ± 4 mmHg, FIO2≅11%); and hypobaric hypoxia (HH at 3000 and 5500 m, HH3000 and HH5500, PB = 525 ± 6 and 380 ± 8 mmHg, respectively, FIO2 = 20.9%). HRV and pulse arterial oxygen saturation (SpO2) were measured at rest seated during a 6 min period in each condition. HRV parameters were analyzed (Kubios HVR Standard, V 3.0) for time (RMSSD) and frequency (LF, HF, LF/HF ratio, and total power). Gas exchanges were collected at rest for 10 min following HRV recording. Results SpO2 decreased in HH3000 (95 ± 3) and HH5500 (81 ± 5), when compared to NN (99 ± 0). SpO2 was higher in NH (86 ± 4) than HH5500 but similar between HN (98 ± 2) and NN. Participants showed lower RMSSD and total power values in NH and HH5500 when compared to NN. In hypoxia, LF/HF ratio was greater in HH5500 than NH, whereas in normoxia, LF/HF ratio was lower in HN than NN. Minute ventilation was higher in HH5500 than in all other conditions. Discussion The present study reports a slight hypobaric effect either in normoxia or in hypoxia on some HRV parameters. In hypoxia, with a more prominent sympathetic activation, the hypobaric effect is likely due to the greater ventilation stimulus and larger desaturation. In normoxia, the HRV differences may come from the hyperoxic breathing and slight breathing pattern change due to hypobaria in HN.
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Affiliation(s)
- Mathias Roland Aebi
- Swiss Aeromedical Center, Swiss Air Force, Dübendorf, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
- Armasuisse, Wissenschaft and Technologie, Thun, Switzerland
- *Correspondence: Mathias Roland Aebi,
| | - Nicolas Bourdillon
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
- Be.care SA, Renens, Switzerland
| | - Denis Bron
- Swiss Aeromedical Center, Swiss Air Force, Dübendorf, Switzerland
| | - Grégoire P. Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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11
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Reveco R, Velásquez M, Bustos L, Goyenechea M, Bachelet V. Determining the Operating Costs of a Medical Surveillance Program for Copper Miners Exposed to High Altitude-Induced Chronic Intermittent Hypoxia in Chile Using a Combination of Microcosting and Time-Driven Activity-Based Costing. Value Health Reg Issues 2019; 20:115-121. [PMID: 31255923 DOI: 10.1016/j.vhri.2019.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 12/25/2018] [Accepted: 01/15/2019] [Indexed: 01/09/2023]
Abstract
BACKGROUND Copper mining installations in Chile use a large number of workers who do their jobs at high altitudes, exposing them to the conditions of chronic intermittent hypobaric hypoxia. The Chilean Safety Association implements the surveillance program. OBJECTIVE This organization, under the sponsorship of the Chilean Superintendency of Social Security, was interested in determining the costs involved in this program to support its decision-making processes and to improve its performance. METHODS Direct operating costs of the Hypoxia Medical Surveillance Program were determined through on-site surveys applied to the organization's local agencies in charge. The microcosting method was used, quantifying personnel costs, consumables, and equipment and overhead costs. Time-driven activity-based costing was partially adapted for the allocation of personnel and equipment costs. Costs concerning activities, groups of activities and items, and average cost per exposed worker were determined. RESULTS The annual costs of the program were $127 299.58. The highest costs corresponded to the assessment activities, which were $89 192.13, representing 60.06% of the total. The labor factor costs were $77 568.50, which represents 60.93% of the total. The average cost per worker in the program is $21.17. CONCLUSIONS The partial adaptation of the time-driven activity-based costing method in combination with the microcosting method provides a suitable solution to determine the total costs of running a healthcare program of this kind. The information generated by this study will aid in the decision-making and management processes of the Hypoxia Medical Surveillance Program.
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Affiliation(s)
- Roberto Reveco
- Departamento de Administración y Economía, Universidad de La Frontera, Temuco, Chile; Centro de Excelencia "Capacitación, Investigación y Gestión para la Salud basada en Evidencias", Universidad de La Frontera, Temuco, Chile.
| | - Mónica Velásquez
- Centro de Excelencia "Capacitación, Investigación y Gestión para la Salud basada en Evidencias", Universidad de La Frontera, Temuco, Chile; Departamento de Especialidades Médicas, Universidad de La Frontera, Temuco, Chile
| | - Luis Bustos
- Centro de Excelencia "Capacitación, Investigación y Gestión para la Salud basada en Evidencias", Universidad de La Frontera, Temuco, Chile; Departamento de Salud Pública, Universidad de La Frontera, Temuco, Chile
| | | | - Vivienne Bachelet
- Medwave Estudios, Santiago, Chile; Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Santiago, Chile
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Orr JE, Heinrich EC, Djokic M, Gilbertson D, Deyoung PN, Anza-Ramirez C, Villafuerte FC, Powell FL, Malhotra A, Simonson T. Adaptive Servoventilation as Treatment for Central Sleep Apnea Due to High-Altitude Periodic Breathing in Nonacclimatized Healthy Individuals. High Alt Med Biol 2018; 19:178-184. [PMID: 29641294 PMCID: PMC6014053 DOI: 10.1089/ham.2017.0147] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 01/20/2018] [Indexed: 12/17/2022] Open
Abstract
Orr, Jeremy E., Erica C. Heinrich, Matea Djokic, Dillon Gilbertson, Pamela N. Deyoung, Cecilia Anza-Ramirez, Francisco C. Villafuerte, Frank L. Powell, Atul Malhotra, and Tatum Simonson. Adaptive servoventilation as treatment for central sleep apnea due to high-altitude periodic breathing in nonacclimatized healthy individuals. High Alt Med Biol. 19:178-184, 2018. AIMS Central sleep apnea (CSA) is common at high altitude, leading to desaturation and sleep disruption. We hypothesized that noninvasive ventilation using adaptive servoventilation (ASV) would be effective at stabilizing CSA at altitude. Supplemental oxygen was evaluated for comparison. METHODS Healthy subjects were brought from sea level to 3800 m and underwent polysomnography on three consecutive nights. Subjects underwent each condition-No treatment, ASV, and supplemental oxygen-in random order. The primary outcome was the effect of ASV on oxygen desaturation index (ODI). Secondary outcomes included oxygen saturation, arousals, symptoms, and comparison to supplemental oxygen. RESULTS Eighteen subjects underwent at least two treatment conditions. There was a significant difference in ODI across the three treatments. There was no statistical difference in ODI between no treatment and ASV (17.1 ± 4.2 vs. 10.7 ± 2.9 events/hour; p > 0.17) and no difference in saturation or arousal index. Compared with no treatment, oxygen improved the ODI (16.5 ± 4.5 events/hour vs. 0.5 ± 0.2 events/hour; p < 0.003), in addition to saturation and arousal index. CONCLUSIONS We found that ASV was not clearly efficacious at controlling CSA in persons traveling to 3800 m, whereas supplemental oxygen resolved CSA. Adjustment in the ASV algorithm may improve efficacy. ASV may have utility in acclimatized persons or at more modest altitudes.
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Affiliation(s)
- Jeremy E. Orr
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California
| | - Erica C. Heinrich
- Department of Medicine, Division of Physiology, University of California San Diego, La Jolla, California
| | - Matea Djokic
- Department of Medicine, Division of Physiology, University of California San Diego, La Jolla, California
| | - Dillon Gilbertson
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California
| | - Pamela N. Deyoung
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California
| | - Cecilia Anza-Ramirez
- Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Francisco C. Villafuerte
- Departamento de Ciencias Biológicas y Fisiológicas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Frank L. Powell
- Department of Medicine, Division of Physiology, University of California San Diego, La Jolla, California
| | - Atul Malhotra
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California
| | - Tatum Simonson
- Department of Medicine, Division of Physiology, University of California San Diego, La Jolla, California
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Moraga FA, López I, Morales A, Soza D, Noack J. The Effect of Oxygen Enrichment on Cardiorespiratory and Neuropsychological Responses in Workers With Chronic Intermittent Exposure to High Altitude (ALMA, 5,050 m). Front Physiol 2018; 9:187. [PMID: 29628892 PMCID: PMC5876232 DOI: 10.3389/fphys.2018.00187] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/23/2018] [Indexed: 12/17/2022] Open
Abstract
It is estimated that labor activity at high altitudes in Chile will increase from 60,000 to 120,000 workers by the year 2020. Oxygenation of spaces improves the quality of life for workers at high geographic altitudes (<5,000 m). The aim of this study was to determine the effect of a mobile oxygen module system on cardiorespiratory and neuropsychological performance in a population of workers from Atacama Large Millimeter/submillimeter Array (ALMA, 5,050 m) radiotelescope in the Chajnantor Valley, Chile. We evaluated pulse oximetry, systolic and diastolic arterial pressure (SAP/DAP), and performed neuropsychological tests (Mini-Mental State examination, Rey-Osterrieth Complex Figure test) at environmental oxygen conditions (5,050 m), and subsequently in a mobile oxygenation module that increases the fraction of oxygen in order to mimic the higher oxygen partial pressure of lower altitudes (2,900 m). The use of module oxygenation at an altitude of 5,050 m, simulating an altitude of 2,900 m, increased oxygen saturation from 84 ± 0.8 to 91 ± 0.8% (p < 0.00001), decreased heart rate from 90 ± 8 to 77 ± 12 bpm (p < 0.01) and DAP from 96 ± 3 to 87 ± 5 mmHg (p < 0.01). In addition, mental cognitive state of workers (Mini-Mental State Examination) shown an increased from 19 to 31 points (p < 0.02). Furthermore, the Rey-Osterrieth Complex Figure test (memory) shown a significant increase from 35 to 70 (p < 0.0001). The results demonstrate that the use of an oxygen module system at 5,050 m, simulating an altitude equivalent to 2,900 m, by increasing FiO2 at 28%, significantly improves cardiorespiratory response and enhances neuropsychological performance in workers exposed to an altitude of 5,050 m.
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Affiliation(s)
- Fernando A. Moraga
- Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
| | - Iván López
- Safety Group, Atacama Large Millimeter Submillimeter Array, Calama, Chile
| | - Alicia Morales
- Departamento de Ciencias de la Salud, Escuela de Enfermería, Universidad Santo Tomás, Santiago, Chile
| | - Daniel Soza
- Safety Group, Atacama Large Millimeter Submillimeter Array, Calama, Chile
| | - Jessica Noack
- Departamento de Ciencias de la Salud, Escuela de Enfermería, Universidad Santo Tomás, Santiago, Chile
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Moraga FA, Miranda G, López V, Vallejos C, Silva D. Chronic Intermittent Hypobaric Hypoxia (4600 M) Attenuates Pulmonary Vasodilation Induced by Acetylcholine or Sodium Nitroprusside. High Alt Med Biol 2018; 19:149-155. [PMID: 29565678 DOI: 10.1089/ham.2017.0012] [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: 11/13/2022] Open
Abstract
Moraga, Fernando A., Giselle Miranda, Vasthi López, Carmen Vallejos, and Daniel Silva. Chronic intermittent hypobaric hypoxia (4600 M) attenuates pulmonary vasodilation induced by acetylcholine or sodium nitroprusside. High Alt Med Biol. 19:149-155, 2018. BACKGROUND Previous studies performed in rats exposed to chronic intermittent hypobaric hypoxia (CIHH), at a simulated altitude of 4600 m, showed reduced nitric oxide (NO) production, increased arginase activity, and increased oxidative stress. However, studies on vascular function are scarce. Our aim was to measure plasma nitrate and nitrite (NOx) concentration and study pulmonary vascular function in rats exposed to CIHH in the presence of potassium chloride (KCl), acetylcholine (Ach), and sodium nitroprusside (SNP). METHODS Thirty male Wistar rats were divided into two groups: A control group (normoxia (N), n = 10) and a CIHH group (2N × 2H × 30 days, n = 20). CIHH exposure was performed in a hypobaric chamber at 428 Torr (4600 m). Noninvasive systolic blood pressure (SBP), heart rate, and body weight (BW) were measured. Blood samples were obtained to measure NOx levels and hematocrit (Hct). CIHH animals that gained BW and presented a Hct <20% and maintained SBP were classified as tolerant, and animals that lost >30% of their BW, increased Hct and SBP >20% were classified as intolerant. Animals were sacrificed and small pulmonary arteries (SPA) were obtained to perform concentration-response curves to KCl, Ach, and SNP. RESULTS AND CONCLUSIONS Intolerant rats (30%) had decreased NOx levels. SPA had a larger vasocontraction response to KCl and a lower dilation response to SNP in the SPA compared to tolerant and control animals. In addition, SPA had a lower dilatation response to Ach compared with the control. Together, these results show that CIHH alters endothelium-dependent vasodilation.
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Affiliation(s)
- Fernando A Moraga
- Laboratory of Physiology, Hypoxia and Vascular Function, Department of Biomedical Science, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
| | - Giselle Miranda
- Laboratory of Physiology, Hypoxia and Vascular Function, Department of Biomedical Science, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
| | - Vasthi López
- Laboratory of Physiology, Hypoxia and Vascular Function, Department of Biomedical Science, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
| | - Carmen Vallejos
- Laboratory of Physiology, Hypoxia and Vascular Function, Department of Biomedical Science, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
| | - Daniel Silva
- Laboratory of Physiology, Hypoxia and Vascular Function, Department of Biomedical Science, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
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Moraga FA, Osorio J, Calderón-Jofré R, Pedreros A. Hemoconcentration During Maximum Exercise in Miners with Chronic Intermittent Exposure to Hypobaric Hypoxia (3800 m). High Alt Med Biol 2017; 19:15-20. [PMID: 29035586 DOI: 10.1089/ham.2017.0011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Moraga, Fernando A., Jorge Osorio, Rodrigo Calderón-Jofré, and Andrés Pedreros. Hemoconcentration during maximum exercise in miners with chronic intermittent exposure to hypobaric hypoxia (3800 m). High Alt Med Biol. 19:15-20, 2018. OBJECTIVE To evaluate the effect of maximum exercise on hemoconcentration in miners with chronic intermittent hypobaric hypoxia (CIHH) at 3800 m. MATERIALS AND METHODS Sixteen miners with CIHH at high altitude (3800 m) were subjected to maximum exercise levels on a cycle ergometer, increasing exercise load by 50 W every 3 minutes at sea level and high altitude (3800 m). During exercise, arterial oxygen saturation and heart rate were measured. Blood samples were taken at each step to measure hemoglobin concentration and hematocrit. Arterial blood oxygen content was also calculated. RESULTS At sea level, a decrease in arterial oxygen saturation to 92.1% ± 2.5% was observed at 150 W and the hematocrit, hemoglobin concentration and oxygen content were not altered. At high altitude, arterial oxygen saturation decreased, reaching 88.2% ± 4.9% at 50 W and remained constant during the entire exercise protocol. Hemoglobin concentration and hematocrit increased reaching 16.4 ± 0.9 g/dL and 48.8% ± 1.6%, respectively, at 100 W and were maintained until recovery. Arterial oxygen content was constant during exercise and increased in the recovery period. CONCLUSION An increase in hemoglobin concentration during exercise compensates for the decline in arterial oxygen saturation, meanwhile arterial oxygen content remains constant.
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Affiliation(s)
- Fernando A Moraga
- 1 Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte , Coquimbo, Chile
| | - Jorge Osorio
- 2 Instituto de Estudios de la Salud , Universidad Arturo Prat, Iquique, Chile
| | - Rodrigo Calderón-Jofré
- 1 Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte , Coquimbo, Chile
| | - Andrés Pedreros
- 1 Laboratorio de Fisiología, Hipoxia y Función Vascular, Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte , Coquimbo, Chile
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Hermand E, Lhuissier FJ, Larribaut J, Pichon A, Richalet JP. Ventilatory oscillations at exercise: effects of hyperoxia, hypercapnia, and acetazolamide. Physiol Rep 2015; 3:3/6/e12446. [PMID: 26109194 PMCID: PMC4510637 DOI: 10.14814/phy2.12446] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Periodic breathing has been found in patients with heart failure and sleep apneas, and in healthy subjects in hypoxia, during sleep and wakefulness, at rest and, recently, at exercise. To unravel the cardiorespiratory parameters liable to modulate the amplitude and period of ventilatory oscillations, 26 healthy subjects were tested under physiological (exercise) and environmental (hypoxia, hyperoxia, hyperoxic hypercapnia) stresses, and under acetazolamide (ACZ) treatment. A fast Fourier transform spectral analysis of breath-by-breath ventilation evidenced an increase in peak power under hypercapnia (vs. normoxia and hyperoxia, P < 0.001) and a decrease under ACZ (vs. placebo, P < 0.001), whereas it was not modified in hyperoxia. period was shortened by exercise in all conditions (vs. rest, P < 0.01) and by hypercapnia (vs. normoxia, P < 0.05) but remained unchanged under ACZ (vs. placebo). peak power was positively related to cardiac output () and in hyperoxia (P < 0.01), in hypercapnia (P < 0.001) and under ACZ (P < 0.001). period was negatively related to and in hyperoxia (P < 0.01 and P < 0.001, respectively), in hypercapnia (P < 0.05 and P < 0.01, respectively) and under ACZ (P < 0.05 and P < 0.01, respectively). Total respiratory cycle time was the main factor responsible for changes in period. In conclusion, exercise, hypoxia, and hypercapnia increase ventilatory oscillations by increasing and , whereas ACZ decreases ventilatory instability in part by a contrasting action on O2 and CO2 sensing. An intrinsic oscillator might modulate ventilation through a complex system where peripheral chemoreflex would play a key role.
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Affiliation(s)
- Eric Hermand
- Université Paris 13 Sorbonne Paris Cité Laboratoire "Hypoxie et poumon", Bobigny, France
| | - François J Lhuissier
- Université Paris 13 Sorbonne Paris Cité Laboratoire "Hypoxie et poumon", Bobigny, France Assistance Publique-Hôpitaux de Paris, Hôpital Avicenne Service de Physiologie explorations fonctionnelles et médecine du sport, Bobigny, France
| | - Julie Larribaut
- Université Paris 13 Sorbonne Paris Cité Laboratoire "Hypoxie et poumon", Bobigny, France
| | - Aurélien Pichon
- Université Paris 13 Sorbonne Paris Cité Laboratoire "Hypoxie et poumon", Bobigny, France
| | - Jean-Paul Richalet
- Université Paris 13 Sorbonne Paris Cité Laboratoire "Hypoxie et poumon", Bobigny, France Assistance Publique-Hôpitaux de Paris, Hôpital Avicenne Service de Physiologie explorations fonctionnelles et médecine du sport, Bobigny, France
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Kayser B. The International Hypoxia Symposium 2015 in Lake Louise: A Report. High Alt Med Biol 2015; 16:261-6. [PMID: 25955961 DOI: 10.1089/ham.2015.0046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Bengt Kayser
- Institute of Sports Sciences of the University of Lausanne and Department of Physiology of the Faculty of Biology and Medicine , Lausanne, Switzerland
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