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Murphey JT, Temple JL, Hostler D. Taste and Appetite at Altitude: A Comprehensive Review of Sensory and Hunger Modulation in High-Altitude Environments. High Alt Med Biol 2024. [PMID: 39122250 DOI: 10.1089/ham.2024.0018] [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: 08/12/2024] Open
Abstract
Introduction: Individuals living or working at high altitudes typically experience altered taste perceptions and reduced appetite. These changes can lead to nutritional deficiencies, affecting the energy balance and body composition. Methods: We conducted a nonsystematic review of PubMed to explore these phenomena and expound on their findings to offer additional insights. Results: Changes in taste and perception are common and typically lead to loss of mass. There are limited practical solutions to mitigate these challenges. Discussion: Gradual acclimatization and tailored nutritional strategies are required to enhance health and performance in high-altitude environments. This review provides critical insights into the intersection of altitude, nutrition, and health.
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Affiliation(s)
- Joshua T Murphey
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York, USA
| | - Jennifer L Temple
- Nutrition and Health Research Laboratory, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York, USA
| | - David Hostler
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York, USA
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2
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Liu Y, Yuan F, Peng Z, Zhan Y, Lin J, Zhang R, Zhang J. Decrease in Cerebral Blood Flow after Reoxygenation Is Associated with Neurological Syndrome Sequelae and Blood Pressure. Brain Sci 2023; 13:1600. [PMID: 38002559 PMCID: PMC10669967 DOI: 10.3390/brainsci13111600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/30/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Changes in cerebral blood flow (CBF) and regulation of cerebral circulation occur at high altitude (HA). However, the changes in CBF and their associations with neurological syndrome sequelae and blood pressure after subjects return to the lowlands remain unclear. In this study, the subjects were 23 college students who were teaching at an altitude of 4300 m for 30 days. These subjects were studied before reaching the HA (Test 1), one week after returning to the lowlands (Test 2), and three months after returning to the lowlands (Test 3). Symptom scores for de-acclimatization syndrome were evaluated. Changes in CBF were measured using the magnetic resonance imaging arterial spin labeling (ASL) technique. Additionally, the velocity of CBF in the cerebral arteries was measured using a transcranial doppler (TCD). In Test 2 vs. Test 1, the peak systolic velocity and mean velocity in the basilar artery were significantly decreased. CBF exhibited significant decreases in the left putamen/cerebellum crus1/vermis and right thalamus/inferior temporal gyrus, while significant increases were observed in the left postcentral gyrus/precuneus and right middle cingulate gyrus/superior frontal gyrus. In Test 3 vs. Test 1, the basilar artery velocity returned to the baseline level, while CBF continued to decrease. The mean global CBF showed a decreasing trend from Test 1 to Test 3. Furthermore, the mean global CBF had a negative correlation with the systolic pressure, pulse pressure, and mean arterial pressure. The decrease in CBF after reoxygenation may underlie the neurological symptoms in subjects returning to the lowlands. Increased blood pressure could serve as a predictor of a decrease in CBF.
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Affiliation(s)
- Yanqiu Liu
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Fengjuan Yuan
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Zhongwei Peng
- Department of Neurology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Yadong Zhan
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Jianzhong Lin
- Department of Radiology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Ran Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
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3
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Chen X, Zhang J, Lin Y, Li Y, Wang H, Wang Z, Liu H, Hu Y, Liu L. Mechanism, prevention and treatment of cognitive impairment caused by high altitude exposure. Front Physiol 2023; 14:1191058. [PMID: 37731540 PMCID: PMC10507266 DOI: 10.3389/fphys.2023.1191058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/05/2023] [Indexed: 09/22/2023] Open
Abstract
Hypobaric hypoxia (HH) characteristics induce impaired cognitive function, reduced concentration, and memory. In recent years, an increasing number of people have migrated to high-altitude areas for work and study. Headache, sleep disturbance, and cognitive impairment from HH, severely challenges the physical and mental health and affects their quality of life and work efficiency. This review summarizes the manifestations, mechanisms, and preventive and therapeutic methods of HH environment affecting cognitive function and provides theoretical references for exploring and treating high altitude-induced cognitive impairment.
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Affiliation(s)
- Xin Chen
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Jiexin Zhang
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
- Faculty of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, Hubei, China
| | - Yuan Lin
- Sichuan Xincheng Biological Co., LTD., Chengdu, Sichuan, China
| | - Yan Li
- Department of General Surgery, The 77th Army Hospital, Leshan, Sichuan, China
| | - Han Wang
- Department of Cardiology, Affiliated Hospital of Southwest Jiaotong University, The Third People’s Hospital of Chengdu, Chengdu, Sichuan, China
| | - Zhanhao Wang
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Huawei Liu
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Yonghe Hu
- Faculty of Medicine, Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Lei Liu
- Medical Research Center, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
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4
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Aarskog NR, Iuell RS, Dunlop O, Sevre K, Bendz B, Rostrup M. Neuropsychological function is associated with hypocapnia at simulated high altitude. Acta Physiol (Oxf) 2023; 237:e13949. [PMID: 36772955 DOI: 10.1111/apha.13949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023]
Affiliation(s)
- Nikolai Ravn Aarskog
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Acute Medicine, Division of Medicine, Oslo University Hospital, Oslo, Norway
| | | | - Oona Dunlop
- Department of Acute Medicine, Division of Medicine, Oslo University Hospital, Oslo, Norway
| | - Knut Sevre
- Department of Cardiology, Division of Cardiovascular & Pulmonary Diseases, Oslo University Hospital, Oslo, Norway
| | - Bjørn Bendz
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Cardiology, Division of Cardiovascular & Pulmonary Diseases, Oslo University Hospital, Oslo, Norway
| | - Morten Rostrup
- Department of Acute Medicine, Division of Medicine, Oslo University Hospital, Oslo, Norway
- Department of Behavioural Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
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5
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Tamilselvam YK, Jog M, Patel RV. Robot-assisted investigation of sensorimotor control in Parkinson's disease. Sci Rep 2023; 13:4751. [PMID: 36959273 PMCID: PMC10036530 DOI: 10.1038/s41598-023-31299-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 03/09/2023] [Indexed: 03/25/2023] Open
Abstract
Sensorimotor control (SMC) is a complex function that involves sensory, cognitive, and motor systems working together to plan, update and execute voluntary movements. Any abnormality in these systems could lead to deficits in SMC, which would negatively impact an individual's ability to execute goal-directed motions. Recent studies have shown that patients diagnosed with Parkinson's disease (PD) have dysfunctions in sensory, motor, and cognitive systems, which could give rise to SMC deficits. However, SMC deficits in PD and how they affect a patient's upper-limb movements have not been well understood. The objective of the study was to investigate SMC deficits in PD and how they affect the planning and correction of upper-limb motions. This was accomplished using a robotic manipulandum equipped with a virtual-reality system. Twenty age-matched healthy controls and fifty-six PD patients (before and after medication) completed an obstacle avoidance task under dynamic conditions (target and obstacles in moving or stationary form, with and without mechanical perturbations). Kinematic information from the robot was used to extract eighteen features that evaluated the SMC functions of the participants. The findings show that the PD patients before medication were 32% slower, reached 16% fewer targets, hit 41% more obstacles, and were 26% less efficient than the control participants, and the difference in these features was statistically significant under dynamic conditions. In addition to the motor deficits, the PD patients also showed deficits in handling high cognitive loads and interpreting sensory cues. Further, the PD patients after medication exhibited worse sensory and cognitive performance than before medication under complex testing conditions. The PD patients also showed deficits in following the computational models leading to poor motor planning.
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Affiliation(s)
- Yokhesh K Tamilselvam
- Canadian Surgical Technologies and Advanced Robotics (CSTAR), University of Western Ontario (UWO), London, ON, N6A 5B9, Canada.
- Department of Electrical and Computer Engineering, University of Western Ontario (UWO), London, ON, N6A 5B9, Canada.
| | - Mandar Jog
- Department of Electrical and Computer Engineering, University of Western Ontario (UWO), London, ON, N6A 5B9, Canada
- Department of Clinical Neurological Sciences, UWO, and the London Movement Disorders Centre, London, ON, Canada
| | - Rajni V Patel
- Canadian Surgical Technologies and Advanced Robotics (CSTAR), University of Western Ontario (UWO), London, ON, N6A 5B9, Canada
- Department of Electrical and Computer Engineering, University of Western Ontario (UWO), London, ON, N6A 5B9, Canada
- Department of Clinical Neurological Sciences, UWO, London, ON, Canada
- Department of Surgery, UWO, London, ON, Canada
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6
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Li L, Zhou Y, Zou S, Wang Y. The Effects of High-Altitude Mountaineering on Cognitive Function in Mountaineers: A Meta-Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:5101. [PMID: 36982007 PMCID: PMC10049572 DOI: 10.3390/ijerph20065101] [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: 02/18/2023] [Revised: 03/04/2023] [Accepted: 03/09/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Nowadays, with the convenience of international traveling and driven by many individuals' fond dreams of challenging high-altitude exercises, high-altitude mountaineering is becoming increasingly popular worldwide. Therefore, we performed a meta-analysis to determine the effects of high-altitude mountaineering on cognitive functions in mountaineers before and after climbing. METHODS After a thorough electronic literature search and selection, eight studies were included in this meta-analysis, and the conducted test cycles ranged from 8 to 140 days. Eight variables were included in this meta-analysis: the Trail-Making Test (TMB), Digit Span-Forward (DSF), Digit Span-Backward (DSB), Finger Tapping Test-Right (FTR) Finger Tapping Test-Left (FTL), Wechsler Memory Scale Visual (WMSV), the Aphasia Screening Test (Verbal Items) (AST-Ver), and the Aphasia Screening Test (Visual Motor Errors) (AST-Vis). The effect sizes (ES) and forest plots of these eight variables were generated. RESULTS Five variables (TMB, ES = 0.39; DSF, ES = 0.57; FTR, ES = 0.50; FTL, ES = 0.16; WMSV, ES = 0.63) out of eight were significantly improved after high-altitude mountaineering, whereas the ES values of DSB, AST-Ver, and AST-Vis did not show significant improvement after climbing. CONCLUSION Despite two limitations, namely, methodological issues inherent in the meta-analysis and the inability to explain high heterogeneity between studies, this study is the first meta-analysis that has attempted to specify and compare the cognitive functions of mountaineers before and after high-altitude mountaineering. Furthermore, as a short-term plateau exercise, high-altitude mountaineering has no significant negative impacts on the cognitive functions of climbers. Future research is needed for a long period of high-altitude mountaineering.
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Affiliation(s)
- Lun Li
- College of Physical Education, China University of Geosciences (Wuhan), Wuhan 430074, China; (L.L.)
| | - Yun Zhou
- College of Physical Education, China University of Geosciences (Wuhan), Wuhan 430074, China; (L.L.)
| | - Shisi Zou
- College of Physical Education, China University of Geosciences (Wuhan), Wuhan 430074, China; (L.L.)
| | - Yongtai Wang
- College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY 14623, USA
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7
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Cognition and Neuropsychological Changes at Altitude-A Systematic Review of Literature. Brain Sci 2022; 12:brainsci12121736. [PMID: 36552195 PMCID: PMC9775937 DOI: 10.3390/brainsci12121736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/05/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
High-altitude (HA) exposure affects cognitive functions, but studies have found inconsistent results. The aim of this systematic review was to evaluate the effects of HA exposure on cognitive functions in healthy subjects. A structural overview of the applied neuropsychological tests was provided with a classification of superordinate cognitive domains. A literature search was performed using PubMed up to October 2021 according to PRISMA guidelines. Eligibility criteria included a healthy human cohort exposed to altitude in the field (at minimum 2440 m [8000 ft]) or in a hypoxic environment in a laboratory, and an assessment of cognitive domains. The literature search identified 52 studies (29 of these were field studies; altitude range: 2440 m-8848 m [8000-29,029 ft]). Researchers applied 112 different neuropsychological tests. Attentional capacity, concentration, and executive functions were the most frequently studied. In the laboratory, the ratio of altitude-induced impairments (64.7%) was twice as high compared to results showing no change or improved results (35.3%), but altitudes studied were similar in the chamber compared to field studies. In the field, the opposite results were found (66.4 % no change or improvements, 33.6% impairments). Since better acclimatization can be assumed in the field studies, the findings support the hypothesis that sufficient acclimatization has beneficial effects on cognitive functions at HA. However, it also becomes apparent that research in this area would benefit most if a consensus could be reached on a standardized framework of freely available neurocognitive tests.
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Garcia SM, Matheson B, Morales-Loredo JH, Jernigan NL, Kanagy NL, Resta TC, Clark RM, Shekarriz R, Gonzalez Bosc LV. Hydrogen sulfide and miR21 are suitable biomarkers of hypoxic exposure. Am J Physiol Regul Integr Comp Physiol 2022; 323:R900-R909. [PMID: 36250874 PMCID: PMC9678419 DOI: 10.1152/ajpregu.00199.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/12/2022] [Accepted: 10/13/2022] [Indexed: 11/22/2022]
Abstract
Hypoxia is the reduction of alveolar partial pressure of oxygen ([Formula: see text]). Military members and people who practice recreational activities from moderate to high altitudes are at risk for hypoxic exposure. Hypoxemia's signs and symptoms vary from asymptomatic to severe responses, such as excessive hypoxic ventilatory responses and residual neurobehavioral impairment. Therefore, it is essential to identify hypoxia-induced biomarkers to indicate people with exposure to hypoxia. Advances have been made in understanding physiological responses to hypoxia, including elevations in circulating levels of endothelin 1 (ET-1) and microRNA 21 (miR-21) and reduction in circulating levels of hydrogen sulfide (H2S). Although the levels of these factors change upon exposure to hypoxia, it is unclear if these changes are sustained on return to normoxia. We hypothesize that hypoxia-induced ET-1 and miR-21 remain elevated, whereas hypoxia-reduction in H2S sustains after returning to normoxic conditions. To test this hypothesis, we exposed male rats to 6 h of 12% O2 and measured circulating levels of ET-1 and miR-21, pre, during, and posthypoxia. We found that ET-1 plasma levels increased in response to hypoxia but returned to normal levels within 30 min after the restoration of normoxia. miR-21 plasma levels and transdermal H2S emissions decreased in response to hypoxia, remaining decreased on return to normoxia, thus following the biomarker criteria. Therefore, this study supports a unique role for plasma miR21 and transdermal H2S as hypoxia biomarkers that could be used to identify individuals after exposure to hypoxia.
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Affiliation(s)
- Selina M Garcia
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Benjamin Matheson
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Juan H Morales-Loredo
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nancy L Kanagy
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Ross M Clark
- Department of Surgery, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | | | - Laura V Gonzalez Bosc
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
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Chang KS, Chiu YH, Kao WF, Yang CCH, How CK, Lin YK, Hwang YS, Chien DK, Huang MK, Kuo TBJ. The changes of electroencephalography in mountaineers on Mount Jade, Taiwan: An observational study. PLoS One 2022; 17:e0275870. [PMID: 36417369 PMCID: PMC9683632 DOI: 10.1371/journal.pone.0275870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 09/23/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The diagnosis of acute mountain sickness, which lacks a reliable and objective diagnostic tool, still depends on the clinical symptoms and signs and remains a major threat and unpredictable disease affecting millions of mountaineers. OBJECTIVES To record electroencephalography signals with small, convenient, wireless equipment and to test whether electroencephalography parameters, which are more sensitive and reliable markers, could predict the symptoms of acute mountain sickness. METHODS Twenty-five participants were enrolled and separated into two groups to climb Mount Jade in Taiwan. We collected electrocardiography signals and arterial oxygen saturation data at ground, moderate (2,400 m), and high altitude (3,400 m). A spectral analysis of the electrocardiography was performed to assess the study subjects' electroencephalography activity at different frequencies (α, β, θ, δ) and the mean power frequency of electrocardiography. The clinical symptoms and Lake Louise Acute Mountain Sickness scores of the subjects were recorded for comparison. RESULTS A significant change in the δ power of electroencephalography was recorded in subjects ascending from the ground to a high altitude of 3,400 m in a 4-day itinerary. In addition, between the two groups of subjects with and without acute mountain sickness (Lake Louise Acute Mountain Sickness scores < 3 and ≥ 3), the δ power of electroencephalography at the fronto-parietal 1 and parietal 3 electrodes at moderate altitude as well as the changes of δ power and mean power frequency of electrocardiography over parietal 4 at high altitude showed a significant difference. At moderate altitude, the increasing δ power of electroencephalography at the parietal 4 electrode was related to the headache symptom of acute mountain sickness before ascending to high altitude. CONCLUSION At moderate altitude, the δ power increase of electroencephalography at the P4 electrode could be a predictor of acute mountain sickness symptoms before ascending to high altitude. Thus, electroencephalography had the potential to identify the risk of acute mountain sickness.
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Affiliation(s)
- Kuo-Song Chang
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
- MacKay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan
| | - Yu-Hui Chiu
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
- Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Wei-Fong Kao
- Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Department of Emergency and Critical Care Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Cheryl C. H. Yang
- Institute of Brain Science, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Sleep Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Department of Education and Research, Taipei City Hospital, Taipei, Taiwan
| | - Chorng-Kuang How
- Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Emergency Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yen-Kuang Lin
- Graduate Institute of Athletics and Coaching Science, National Taiwan Sport University, Taoyuan, Taiwan
| | - Yuh-Shyan Hwang
- Department of Electronic Engineering, National Taipei University of Technology, Taipei, Taiwan
| | - Ding-Kuo Chien
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Ming-Kun Huang
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
- Department of Electronic Engineering, National Taipei University of Technology, Taipei, Taiwan
- * E-mail: (MKH); (TBJK)
| | - Terry B. J. Kuo
- Institute of Brain Science, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Sleep Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Department of Education and Research, Taipei City Hospital, Taipei, Taiwan
- Clinical Research Center, Taoyuan Psychiatric Center, Ministry of Health and Welfare, Taoyuan, Taiwan
- * E-mail: (MKH); (TBJK)
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10
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Li Y, Wang Y. Effects of Long-Term Exposure to High Altitude Hypoxia on Cognitive Function and Its Mechanism: A Narrative Review. Brain Sci 2022; 12:808. [PMID: 35741693 PMCID: PMC9221409 DOI: 10.3390/brainsci12060808] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/15/2022] [Accepted: 06/17/2022] [Indexed: 01/27/2023] Open
Abstract
Cognitive function is affected by low pressure and hypoxia in high-altitude environments, and is regulated by altitude and exposure time. With the economic development in the Qinghai-Tibet Plateau, the increase in work and study activities, as well as the development of plateau tourism, mountaineering, and other activities, the number of plateau immigrants is increasing daily. Long-term hypoxia challenges human physical and mental health, restricts work efficiency, and thus affects plateau economic development and human wellbeing. Therefore, it is of scientific and social significance to study how long-term exposure to the hypoxic plateau environment affects the physical and mental health of lowlanders as part of the ongoing development of the current plateau region. In this paper, we reviewed the research progress and mechanism of the effects of long-term (≥1 year) high-altitude (>2500 m) hypoxia exposure on the cognitive function of lowlanders, and suggested that the scope and sample size of the research should be expanded in the future, and that follow-up studies should be carried out to explore the time threshold of cognitive impairment and its compensatory or repair mechanism.
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Affiliation(s)
- Yuan Li
- Center on Aging Psychology, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China;
- Plateau Brain Science Research Center, Tibet University/South China Normal University, Lhasa 850012, China
| | - Yan Wang
- Center on Aging Psychology, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China;
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
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11
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Falla M, Giardini G, Angelini C. Recommendations for traveling to altitude with neurological disorders. J Cent Nerv Syst Dis 2021; 13:11795735211053448. [PMID: 34955663 PMCID: PMC8695750 DOI: 10.1177/11795735211053448] [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: 03/16/2021] [Revised: 09/02/2021] [Accepted: 09/28/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Several neurological conditions might worsen with the exposure to high altitude (HA). The aim of this review was to summarize the available knowledge on the neurological HA illnesses and the risk for people with neurological disorders to attend HA locations. METHODS A search of literature was conducted for several neurological disorders in PubMed and other databases since 1970. The neurological conditions searched were migraine, different cerebrovascular disease, intracranial space occupying mass, multiple sclerosis, peripheral neuropathies, neuromuscular disorders, epileptic seizures, delirium, dementia, and Parkinson's disease (PD). RESULTS Attempts were made to classify the risk posed by each condition and to provide recommendations regarding medical evaluation and advice for or against traveling to altitude. Individual cases should be advised after careful examination and risk evaluation performed either in an outpatient mountain medicine service or by a physician with knowledge of HA risks. Preliminary diagnostic methods and anticipation of neurological complications are needed. CONCLUSIONS Our recommendations suggest absolute contraindications to HA exposure for the following neurological conditions: (1) Unstable conditions-such as recent strokes, (2) Diabetic neuropathy, (3) Transient ischemic attack in the last month, (4) Brain tumors, and 5. Neuromuscular disorders with a decrease of forced vital capacity >60%. We consider the following relative contraindications where decision has to be made case by case: (1) Epilepsy based on recurrence of seizure and stabilization with the therapy, (2) PD (± obstructive sleep apnea syndrome-OSAS), (3) Mild Cognitive Impairment (± OSAS), and (4) Patent foramen ovale and migraine have to be considered risk factors for acute mountain sickness.
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Affiliation(s)
- Marika Falla
- Institute of Mountain Emergency
Medicine, Eurac Research, Bolzano, Italy
- Center for Mind/Brain Sciences,
CIMeC, University of Trento, Rovereto, Italy
| | - Guido Giardini
- Mountain Medicine and Neurology
Centre, Valle D’Aosta Regional
Hospital, Aosta, Italy
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12
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Qiu Q, Lv P, Zhongshen Y, Yuan F, Zhang X, Zhou X, Li S, Liu X, Zhang J. Electrophysiological mechanisms underlying hypoxia-induced deficits in visual spatial and non-spatial discrimination. Physiol Rep 2021; 9:e15036. [PMID: 34558212 PMCID: PMC8461214 DOI: 10.14814/phy2.15036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 12/16/2022] Open
Abstract
Impaired visual cognition in residents of hypoxic environment has been widely reported; however, the underlying electrophysiological mechanisms remain unclear. In this study, 23 college students underwent three sessions of a Clock task test before a 30-day high-altitude exposure (Test 1) and 1 week (Test 2) and 3 months (Test 3) after they returned to lowlands. The Clock task consists of a visual spatial angle and a visual non-spatial color discrimination subtask. Simultaneously, electroencephalography (EEG) was recorded during the Clock task. The behavioral results showed that, compared with Test 1, accuracy in Test 2 was significantly decreased in both the Angle and Color tasks, and reaction time (RT) was significantly increased in the Angle task. The event-related potentials results showed that, during both tasks amplitudes of the occipital N1 and P3 components during both tasks were significantly decreased in Test 2, compared with Test 1. Moreover, N1 amplitude was negatively correlated with RT and positively correlated with accuracy. Further time-frequency EEG analysis showed that theta power at occipital sites was significantly decreased in both tasks in Test 2, compared with Test 1, and was negatively correlated with RT in the Angle task. In Test 3, both the behavioral performance and EEG activity recovered to the baseline level in Test 1. These findings suggested that hypoxia impairs both visual spatial and visual non-spatial discriminations, and these impairments can recover after subjects return to lowlands. Inhibition of brain electrophysiological activity in the visual cortex may explain the deficits in visual cognition.
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Affiliation(s)
- Qi Qiu
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Pengpeng Lv
- Department of Clinical MedicineSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Yihao Zhongshen
- Department of Traditional Chinese MedicineSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Fengjuan Yuan
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Xinjuan Zhang
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Xiuzhu Zhou
- Department of Gynecology and ObstetricsThe First Affiliated Hospital of Xiamen UniversityXiamenFujianChina
| | - Shanhua Li
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Xiaonan Liu
- Institute of PsychologySchool of Public PolicyXiamen UniversityXiamenFujianChina
| | - Jiaxing Zhang
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
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13
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Carr JMJR, Caldwell HG, Ainslie PN. Cerebral blood flow, cerebrovascular reactivity and their influence on ventilatory sensitivity. Exp Physiol 2021; 106:1425-1448. [PMID: 33932955 DOI: 10.1113/ep089446] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 04/26/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the topic of this review? Cerebrovascular reactivity to CO2 , which is a principal factor in determining ventilatory responses to CO2 through the role reactivity plays in determining cerebral extra- and intracellular pH. What advances does it highlight? Recent animal evidence suggests central chemoreceptor vasculature may demonstrate regionally heterogeneous cerebrovascular reactivity to CO2 , potentially as a protective mechanism against excessive CO2 washout from the central chemoreceptors, thereby allowing ventilation to reflect the systemic acid-base balance needs (respiratory changes in P aC O 2 ) rather than solely the cerebral needs. Ventilation per se does not influence cerebrovascular reactivity independent of changes in P aC O 2 . ABSTRACT Alveolar ventilation and cerebral blood flow are both predominantly regulated by arterial blood gases, especially arterial P C O 2 , and so are intricately entwined. In this review, the fundamental mechanisms underlying cerebrovascular reactivity and central chemoreceptor control of breathing are covered. We discuss the interaction of cerebral blood flow and its reactivity with the control of ventilation and ventilatory responsiveness to changes in P C O 2 , as well as the lack of influence of ventilation itself on cerebrovascular reactivity. We briefly summarize the effects of arterial hypoxaemia on the relationship between ventilatory and cerebrovascular response to both P C O 2 and P O 2 . We then highlight key methodological considerations regarding the interaction of reactivity and ventilatory sensitivity, including the following: regional heterogeneity of cerebrovascular reactivity; a pharmacological approach for the reduction of cerebral blood flow; reactivity assessment techniques; the influence of mean arterial blood pressure; and sex-related differences. Finally, we discuss ventilatory and cerebrovascular control in the context of high altitude and congestive heart failure. Future research directions and pertinent questions of interest are highlighted throughout.
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Affiliation(s)
- Jay M J R Carr
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
| | - Hannah G Caldwell
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
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14
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Falla M, Papagno C, Dal Cappello T, Vögele A, Hüfner K, Kim J, Weiss EM, Weber B, Palma M, Mrakic-Sposta S, Brugger H, Strapazzon G. A Prospective Evaluation of the Acute Effects of High Altitude on Cognitive and Physiological Functions in Lowlanders. Front Physiol 2021; 12:670278. [PMID: 33995130 PMCID: PMC8113692 DOI: 10.3389/fphys.2021.670278] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
Cognitive function impairment due to high altitude exposure has been reported with some contradictory results regarding the possible selective cognitive domain involvement. We prospectively evaluated in 36 lowlanders, exposed for 3 consecutive days to an altitude of 3,269 m, specific cognitive abilities (attention, processing speed, and decision-making) required to safely explore the mountains, as well as to work at altitude. We simultaneously monitored the physiological parameters. Our study provides evidence of a reduced processing speed in lowlanders when exposed to altitude in the first 24 h. There was a fairly quick recovery since this impairment was no more detectable after 36 h of exposure. There were no clinically relevant effects on decision-making, while psychomotor vigilance was unaffected at altitude except for individuals with poor sleep. Significant changes were seen in physiological parameters (increased heart rate and reduced peripheral oxygen saturation). Our results may have practical implications, suggesting that individuals should practice prudence with higher ascent when performing risky activities in the first 24–36 h, even at altitudes below 3,500 m, due to an impairment of the cognitive performance that could worsen and lead to accidents.
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Affiliation(s)
- Marika Falla
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy.,Center for Mind/Brain Sciences CIMeC, University of Trento, Rovereto, Italy
| | - Costanza Papagno
- Center for Mind/Brain Sciences CIMeC, University of Trento, Rovereto, Italy.,Department of Psychology, University of Milano-Bicocca, Milan, Italy
| | - Tomas Dal Cappello
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Anna Vögele
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Katharina Hüfner
- Department of Psychiatry, Psychotherapy and Psychosomatics, Division of Psychiatry II, Medical University of Innsbruck, Innsbruck, Austria
| | - Jenny Kim
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, United States
| | - Elisabeth M Weiss
- Department of Psychology, University of Innsbruck, Innsbruck, Austria
| | - Bernhard Weber
- Department of Psychology, University of Graz, Graz, Austria
| | - Martin Palma
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | | | - Hermann Brugger
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Giacomo Strapazzon
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
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15
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Li Z, Xue X, Li X, Bao X, Yu S, Wang Z, Liu M, Ma H, Zhang D. Neuropsychological effect of working memory capacity on mental rotation under hypoxia environment. Int J Psychophysiol 2021; 165:18-28. [PMID: 33839196 DOI: 10.1016/j.ijpsycho.2021.03.012] [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: 09/29/2020] [Revised: 03/19/2021] [Accepted: 03/29/2021] [Indexed: 11/30/2022]
Abstract
High-altitude exposure induces the decline of spatial manipulation such as mental rotation which is limited by working memory capacity, but the underlying neuropsychological effect remains to be identified. We evaluated the mental rotation task and the contralateral delay activity (CDA) task under hypoxia environment using the event-related potential. When compared with the controls, the behavior response was slowed on two tasks in the high-altitude group. The declined mental rotation and the decreased working memory capacity were synchronously related to the amplitudes of P50 and CDA, respectively. The P50 during mental rotation was positively correlated to that of rotation-related negativity (RRN) component, so was with the CDA. Time-frequency analysis showed that the beta/alpha power in mental rotation and the theta/alpha/beta power in CDA were enhanced in the high-altitude group. The present study might suggest that the decline of working memory capacity induced poor performance of mental rotation, which may be derived from a bottom-up sensory gating deficit reflected by P50.
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Affiliation(s)
- Zefeng Li
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, China
| | - Xiaojuan Xue
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, China
| | - Xiaoyan Li
- Plateau Brain Science Research Center, South China Normal University/Tibet University, China
| | - Xiaohua Bao
- Plateau Brain Science Research Center, South China Normal University/Tibet University, China
| | - Sifang Yu
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, China
| | - Zengjian Wang
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, China
| | - Ming Liu
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, China; Plateau Brain Science Research Center, South China Normal University/Tibet University, China
| | - Hailin Ma
- Plateau Brain Science Research Center, South China Normal University/Tibet University, China
| | - Delong Zhang
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, China; Plateau Brain Science Research Center, South China Normal University/Tibet University, China.
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16
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Physiology, pathophysiology and (mal)adaptations to chronic apnoeic training: a state-of-the-art review. Eur J Appl Physiol 2021; 121:1543-1566. [PMID: 33791844 PMCID: PMC8144079 DOI: 10.1007/s00421-021-04664-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/04/2021] [Indexed: 02/08/2023]
Abstract
Breath-hold diving is an activity that humans have engaged in since antiquity to forage for resources, provide sustenance and to support military campaigns. In modern times, breath-hold diving continues to gain popularity and recognition as both a competitive and recreational sport. The continued progression of world records is somewhat remarkable, particularly given the extreme hypoxaemic and hypercapnic conditions, and hydrostatic pressures these athletes endure. However, there is abundant literature to suggest a large inter-individual variation in the apnoeic capabilities that is thus far not fully understood. In this review, we explore developments in apnoea physiology and delineate the traits and mechanisms that potentially underpin this variation. In addition, we sought to highlight the physiological (mal)adaptations associated with consistent breath-hold training. Breath-hold divers (BHDs) are evidenced to exhibit a more pronounced diving-response than non-divers, while elite BHDs (EBHDs) also display beneficial adaptations in both blood and skeletal muscle. Importantly, these physiological characteristics are documented to be primarily influenced by training-induced stimuli. BHDs are exposed to unique physiological and environmental stressors, and as such possess an ability to withstand acute cerebrovascular and neuronal strains. Whether these characteristics are also a result of training-induced adaptations or genetic predisposition is less certain. Although the long-term effects of regular breath-hold diving activity are yet to be holistically established, preliminary evidence has posed considerations for cognitive, neurological, renal and bone health in BHDs. These areas should be explored further in longitudinal studies to more confidently ascertain the long-term health implications of extreme breath-holding activity.
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17
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Memantine ameliorates cognitive impairment induced by exposure to chronic hypoxia environment at high altitude by inhibiting excitotoxicity. Life Sci 2021; 270:119012. [PMID: 33422543 DOI: 10.1016/j.lfs.2020.119012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 12/19/2020] [Accepted: 12/25/2020] [Indexed: 01/23/2023]
Abstract
AIMS Memantine is a non-competitive antagonist of glutamatergic NMDA receptor that is mainly used in the treatment of Alzheimer's disease. The excitatory toxicity mediated by glutamate via glutamatergic receptor signals is considered to be one of the mechanisms mediating neuronal injury and cognitive impairment after exposure to a hypoxic environment at a high altitude. Therefore, in this study, we hypothesized that inhibiting glutamate signaling using memantine could alleviate neuronal injury and cognitive impairment in rats exposed to chronic hypoxia. MAIN METHODS we made animal models in the natural environment of the Qinghai-Tibet Plateau at an altitude of 4300 m, and used animal behavior, morphology, molecular biology and other methods to evaluate the impact of chronic hypoxia exposure on cognitive function and the neuroprotective effect of Memantine. KEY FINDINGS Our results showed that the expression of NMDA receptors increased, while the expression of AMPA receptors decreased, after 4 weeks of chronic hypoxia exposure. Concomitantly, apoptotic neuronal cell death in the hippocampus and frontal cortex was significantly increased, along with levels of oxidative stress, whereas innate ability to inhibit free radicals decreased. Moreover, after 8 weeks of hypoxia exposure, learning, memory, and space exploration abilities were significantly decreased. Notably, after treatment with memantine, apoptotic neuronal cell death, oxidative stress, and free radical levels decreased, and the cognitive function of the animals improved. SIGNIFICANCE Present study shows that chronic hypoxia can produce the excitatory toxicity leading to neural injury and cognitive impairment that can be suppressed with memantine treatment by inhibiting excitatory toxicity.
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18
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Lee MH, Yun CH, Min A, Hwang YH, Lee SK, Kim DY, Thomas RJ, Han BS, Shin C. Altered structural brain network resulting from white matter injury in obstructive sleep apnea. Sleep 2020; 42:5526734. [PMID: 31260533 DOI: 10.1093/sleep/zsz120] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/22/2019] [Indexed: 02/06/2023] Open
Abstract
STUDY OBJECTIVES To assess, using fractional anisotropy (FA) analysis, alterations of brain network connectivity in adults with obstructive sleep apnea (OSA). Abnormal networks could mediate clinical functional deficits and reflect brain tissue injury. METHODS Structural brain networks were constructed using diffusion tensor imaging (DTI) from 165 healthy (age 57.99 ± 6.02 years, male 27.9%) and 135 OSA participants (age 59.01 ± 5.91 years, male 28.9%) and global network properties (strength, global efficiency, and local efficiency) and regional efficiency were compared between groups. We examined MRI biomarkers of brain tissue injury using FA analysis and its effect on the network properties. RESULTS Differences between groups of interest were noted in global network properties (p-value < 0.05, corrected), and regional efficiency (p-value < 0.05, corrected) in the left middle cingulate and paracingulate gyri, right posterior cingulate gyrus, and amygdala. In FA analysis, OSA participants showed lower FA values in white matter (WM) of the right transverse temporal, anterior cingulate and paracingulate gyri, and left postcentral, middle frontal and medial frontal gyri, and the putamen. After culling fiber tracts through WM which showed significant differences in FA, we observed no group difference in network properties. CONCLUSIONS Changes in WM integrity and structural connectivity are present in OSA participants. We found that the integrity of WM affected brain network properties. Brain network analysis may improve understanding of neurocognitive deficits in OSA, enable longitudinal tracking, and provides explanations for specific symptoms and recovery kinetics.
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Affiliation(s)
- Min-Hee Lee
- Translational Imaging Laboratory, Children's Hospital of Michigan, Detroit, MI.,Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI
| | - Chang-Ho Yun
- Department of Neurology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Areum Min
- Department of Biomedical Engineering, Yonsei University, Wonju, Republic of Korea
| | - Yoon Ho Hwang
- Department of Biomedical Engineering, Yonsei University, Wonju, Republic of Korea
| | - Seung Ku Lee
- Institute of Human Genomic Study, College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Dong Youn Kim
- Department of Biomedical Engineering, Yonsei University, Wonju, Republic of Korea
| | - Robert J Thomas
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Bong Soo Han
- Department of Radiological Science, Yonsei University, Wonju, Republic of Korea
| | - Chol Shin
- Institute of Human Genomic Study, College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea.,Department of Pulmonary Sleep and Critical Care Medicine Disorder Center, College of Medicine, Korea University, Ansan, Republic of Korea
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19
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Sharma P, Tulsawani R. Ganoderma lucidum aqueous extract prevents hypobaric hypoxia induced memory deficit by modulating neurotransmission, neuroplasticity and maintaining redox homeostasis. Sci Rep 2020; 10:8944. [PMID: 32488040 PMCID: PMC7265456 DOI: 10.1038/s41598-020-65812-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 05/11/2020] [Indexed: 02/04/2023] Open
Abstract
Oxidative stress due to hypobaric hypoxia at extreme altitudes causes severe neuronal damage and irreversible cognitive loss. Owing to contraindications of current drug therapies, the aim of the study was to investigate memory enhancing potential of aqueous extract of Ganoderma lucidum (GLAQ) and underlying neuroprotective mechanism using rat hypobaric hypoxia test model. Rats exposed to hypobaric hypoxia showed deranged spatial memory in morris water maze test with hippocampal damage and vasogenic cerebral edema. All these changes were prevented with GLAQ treatment. Blood and biochemical analysis revealed activation of hypoxic ventilatory response, red blood cells induction, reversal of electrolyte and redox imbalance, and restoration of cellular bioenergetic losses in GLAQ treated animals. Notably, GLAQ treatment ameliorated levels of neurotransmitters (catecholamines, serotonin, glutamate), prevented glucocorticoid and α-synuclein surge, improved neuroplasticity by upregulating CREB/p-CREB/BDNF expression via ERK1/ERK2 induction. Further, restoration of nuclear factor erythroid 2-related factor with stabilization of hypoxia inducible factors and inflammatory markers were evidenced in GLAQ treated rats which was additionally established in gene reporter array using an alternative HT22 cell test model. Conclusively, our studies provide novel insights into systemic to molecular level protective mechanism by GLAQ in combating hypobaric hypoxia induced oxidative stress and memory impairment.
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Affiliation(s)
- Purva Sharma
- Defence Institute of Physiology and Allied Sciences (DIPAS), Lucknow Road, Timarpur, Delhi, 110054, India
| | - Rajkumar Tulsawani
- Defence Institute of Physiology and Allied Sciences (DIPAS), Lucknow Road, Timarpur, Delhi, 110054, India.
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20
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Can High Altitude Exacerbate a Remittent Alcohol Use Disorder in a Patient With a History of Panic Attacks? ADDICTIVE DISORDERS & THEIR TREATMENT 2020. [DOI: 10.1097/adt.0000000000000183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Effects of high altitude mountaineering on body composition: a systematic review. NUTR HOSP 2020; 36:1189-1195. [PMID: 31516006 DOI: 10.20960/nh.02582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Introduction High altitude mountaineering is characterized by high energetic requirements due to the environment in which the activity is developed: negative energy balance, extreme cold, high altitude and the assumption of potential risks can be found during the practice of this sport. High altitude mountaineering, as a result of the previous factors, induces changes in body composition which have never been studied previously in a systematic review. A search within four different databases (PubMed, SportDiscus, Scopus and Medline) was performed using the thesaurus terms "Mountaineering" and "Body composition". A second search was performed using the following terms "Altitude" and "Body composition". The selection criteria included studies with healthy adults which evaluated the effects of at least 14 days of uninterrupted stays at altitudes above 4,000 m. The studies included in the review assessed body composition through different methods such as anthropometry, bioimpedance, dual energy x-ray absorptiometry, hydrostatic weighing and air displacement plethysmography. The search was performed up to and including December 1st 2018. Eleven observational studies met the inclusion criteria. All studies reported weight loss, of which five reported significant reductions in lean mass and six reported reductions in fat mass. Also, three studies reported reductions in both fat mass and lean mass. Current evidence is limited to observational studies with important confounding factors affecting the final conclusions. Longitudinal studies with a better methodological design and control groups are needed in order to verify these results.
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22
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Algaze I, Phillips L, Inglis P, Lathrop G, Gadbois J, Rizzolo K, Harris NS. Incidence of Mild Cognitive Impairment with Ascending Altitude. High Alt Med Biol 2020; 21:184-191. [PMID: 32282276 DOI: 10.1089/ham.2019.0111] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: This study aimed to longitudinally quantify the prevalence of mild cognitive impairment (MCI) in individual trekkers at three different ascending altitudes (Site 1: ∼3500 m, Site 2: ∼4400 m, and Site 3: ∼5100 m). We correlated these findings with the presence of acute mountain sickness (AMS). Materials and Methods: We performed serial assays using the environmental quick mild cognitive impairment (eQMCI) score on 103 English-speaking 18- to 65-year-old volunteers trekking to Everest Base Camp in Nepal during spring 2016. We defined MCI as a score less than 67 (lower scores indicating more cognitive impairment). Additional data collected included the Lake Louise Score, demographics, and other possible confounders. Results: eQMCI scores significantly decreased with ascent from Site 1 to 2 (a score of 78.95 [SD = 7.96] to 74.67 [SD = 8.8] [Site 1-2 p = 0.04]), but then increased on ascent to Site 3 to 83.68 (SD = 8.67) (Site 1-3 p = <0.0001, Site 2-3 p = <0.0001). However, subjects who fulfilled eQMCI criteria for MCI increased despite the overall improvement in score: 6.8% (N = 7) at Site 1, 18.7% (N = 14) at Site 2, and 3.3% (N = 2) at Site 3. Incidence of AMS at Sites 1, 2, and 3 was 22.3% (N = 23), 21.3% (N = 16), and 48.3% (N = 29), respectively. Of those with MCI, 1.94% met criteria for AMS at Site 1 (p = 0.0017), 2.67% at Site 2 (p = 0.6949), and 3.33% at Site 3 (p = <0.0001). Conclusions: There is a significant incidence of MCI at high altitude, even in those without subjective findings of AMS. Interestingly, subjects with a decline in cognitive function show an increasing trend for developing AMS at higher altitude. Future research on the clinical impact of MCI on a subject's health, judgment, and performance remains to be elucidated.
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Affiliation(s)
- Isabel Algaze
- Department of Emergency Medicine, University of California Irvine Medical Center, Orange, California, USA
| | - Lara Phillips
- Department of Emergency Medicine, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA
| | | | - Gabriel Lathrop
- Western University of Health Sciences College of Osteopathic Medicine of the Pacific-Northwest, Lebanon, Oregon, USA
| | - Jaclyn Gadbois
- Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, Minnesota, USA
| | - Katherine Rizzolo
- Department of Internal Medicine, Maine Medical Center, Portland, Maine, USA
| | - N Stuart Harris
- Division of Wilderness Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
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23
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Tavares-Silva E, Donatto FF, Medeiros RMV, Santos SA, Caris AV, Thomatieli-Santos RV. Carbohydrate supplementation and psychophysiological responses during moderate exercise in hypoxia. J Int Soc Sports Nutr 2020; 17:3. [PMID: 31906976 PMCID: PMC6945642 DOI: 10.1186/s12970-019-0331-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 12/12/2019] [Indexed: 12/14/2022] Open
Abstract
Background Rating of Perceived Exertion (RPE) is a subjective scale to monitor overload and fatigue during exercise. Hypoxia may worsen the perception of fatigue, compromising the self-reported perception of effort and increasing RPE. The objective was to evaluate the effects of carbohydrate (CHO) supplementation on RPE during exercise in hypoxia simulating 4200 m. Methods Eight male physically active volunteers performed two exercises at 50% VO2peak and 1% slope: exercise in hypoxia + placebo or exercise in hypoxia + CHO (6% maltodextrin) with supplementation at 20, 40, and 60 min during exercise. Oxygen Saturation (SaO2%) was assessed at baseline and after exercise, while RPE and HR were measured each 10 min during the trial. Results SaO2% decreased after exercise in both conditions of hypoxia compared to rest. The RPE did not differ between groups. However, the RPE increased in hypoxia after 20 min of exercise in relation to 10 min. The Area Under the Curve (AUC) of RPE was lower in hypoxia + CHO compared to hypoxia. The AUC of the HR/RPE ratio in the hypoxia + CHO group was higher in relation to hypoxia. Conclusions Our results indicate that CHO supplementation does not change RPE induced by 60 min of exercise at 50% VO2peak in hypoxia equivalent to 4200 m at the different times analyzed. However, in hypoxia + CHO the (AUC)-60 min of total RPE decreased during exercise, while the heart rate/RPE ratio improved, indicating lower RPE in the hypoxic environment.
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Affiliation(s)
- E Tavares-Silva
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - F F Donatto
- Department of Bioscience, Universidade Federal de São Paulo, Rua Silva Jardim, 136 - Vila Mathias, Santos, SP, 11015-020, Brazil
| | - R M V Medeiros
- Centro Universitário do Rio Grande do Norte (UNI-RN), Natal, Brazil
| | - S A Santos
- Department of Bioscience, Universidade Federal de São Paulo, Rua Silva Jardim, 136 - Vila Mathias, Santos, SP, 11015-020, Brazil
| | - A V Caris
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - R V Thomatieli-Santos
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil. .,Department of Bioscience, Universidade Federal de São Paulo, Rua Silva Jardim, 136 - Vila Mathias, Santos, SP, 11015-020, Brazil.
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24
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Ando S, Komiyama T, Sudo M, Higaki Y, Ishida K, Costello JT, Katayama K. The interactive effects of acute exercise and hypoxia on cognitive performance: A narrative review. Scand J Med Sci Sports 2019; 30:384-398. [PMID: 31605635 DOI: 10.1111/sms.13573] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 09/09/2019] [Accepted: 10/04/2019] [Indexed: 12/13/2022]
Abstract
Acute moderate intensity exercise has been shown to improve cognitive performance. In contrast, hypoxia is believed to impair cognitive performance. The detrimental effects of hypoxia on cognitive performance are primarily dependent on the severity and duration of exposure. In this review, we describe how acute exercise under hypoxia alters cognitive performance, and propose that the combined effects of acute exercise and hypoxia on cognitive performance are mainly determined by interaction among exercise intensity and duration, the severity of hypoxia, and duration of exposure to hypoxia. We discuss the physiological mechanism(s) of the interaction and suggest that alterations in neurotransmitter function, cerebral blood flow, and possibly cerebral metabolism are the primary candidates that determine cognitive performance when acute exercise is combined with hypoxia. Furthermore, acclimatization appears to counteract impaired cognitive performance during prolonged exposure to hypoxia although the precise physiological mechanism(s) responsible for this amelioration remain to be elucidated. This review has implications for sporting, occupational, and recreational activities at terrestrial high altitude where cognitive performance is essential. Further studies are required to understand physiological mechanisms that determine cognitive performance when acute exercise is performed in hypoxia.
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Affiliation(s)
- Soichi Ando
- Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan
| | - Takaaki Komiyama
- Center for Education in Liberal Arts and Sciences, Osaka University, Osaka, Japan
| | - Mizuki Sudo
- Meiji Yasuda Life Foundation of Health and Welfare, Tokyo, Japan
| | - Yasuki Higaki
- Faculty of Sports Science, Fukuoka University, Fukuoka, Japan
| | - Koji Ishida
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan
| | - Joseph T Costello
- Extreme Environments Laboratory, Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Keisho Katayama
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan
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Ray K, Kishore K, Vats P, Bhattacharyya D, Akunov A, Maripov A, Sarybaev A, Singh SB, Kumar B. A Temporal Study on Learning and Memory at High Altitude in Two Ethnic Groups. High Alt Med Biol 2019; 20:236-244. [PMID: 31210541 DOI: 10.1089/ham.2018.0139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Introduction: Cognitive function has been compromised during high-altitude (HA) exposure due to slowing of mental processing. Materials and Methods: A total of 20 Indian and 20 Kyrgyz soldiers were studied at 4111 m to assess cognitive function in two different ethnic groups. Paired associate learning, pattern recognition memory, spatial span (SSP), spatial working memory (SWM), choice reaction time (CRT), and simple reaction time (SRT) were evaluated at sea level and on days 3, 7, 14, and 21 of HA stay and on day 3 of deinduction. Results: All the parameters were significantly affected at HA. Indian soldiers were acclimatized by 7 days but Kyrgyz soldiers required 21 days for acclimatization. A slow impairment in SWM, CRT, and SRT was observed in Kyrgyz soldiers than in Indian soldiers and it continues throughout 21 days of HA stay, but for Indian soldiers the deterioration was maximum on day 7 and improvement in SWM, CRT, and SRT was observed on day 14 and close to baseline value on day 21. After deinduction, although Indian soldiers attained the normal value, Kyrgyz soldiers had higher value than baseline in SSP, SWM, CRT, and SRT. Conclusion: Difference in the cognitive performances of Indian and Kyrgyz soldiers may be due to the ethnogenetic diversity of these two groups.
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Affiliation(s)
- Koushik Ray
- Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Delhi, India
| | - Krishna Kishore
- Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Delhi, India
| | - Praveen Vats
- Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Delhi, India
| | - Debojyoti Bhattacharyya
- Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Delhi, India
| | - Almaz Akunov
- Kyrgyz-Indian Mountain Biomedical Research Centre, Bishkek, Kyrgyzstan
| | | | - Akpay Sarybaev
- Kyrgyz-Indian Mountain Biomedical Research Centre, Bishkek, Kyrgyzstan
| | - Shashi Bala Singh
- Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Delhi, India
| | - Bhuvnesh Kumar
- Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Delhi, India
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26
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Heinrich EC, Djokic MA, Gilbertson D, DeYoung PN, Bosompra NO, Wu L, Anza-Ramirez C, Orr JE, Powell FL, Malhotra A, Simonson TS. Cognitive function and mood at high altitude following acclimatization and use of supplemental oxygen and adaptive servoventilation sleep treatments. PLoS One 2019; 14:e0217089. [PMID: 31188839 PMCID: PMC6561544 DOI: 10.1371/journal.pone.0217089] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 05/03/2019] [Indexed: 11/19/2022] Open
Abstract
Impairments in cognitive function, mood, and sleep quality occur following ascent to high altitude. Low oxygen (hypoxia) and poor sleep quality are both linked to impaired cognitive performance, but their independent contributions at high altitude remain unknown. Adaptive servoventilation (ASV) improves sleep quality by stabilizing breathing and preventing central apneas without supplemental oxygen. We compared the efficacy of ASV and supplemental oxygen sleep treatments for improving daytime cognitive function and mood in high-altitude visitors (N = 18) during acclimatization to 3,800 m. Each night, subjects were randomly provided with ASV, supplemental oxygen (SpO2 > 95%), or no treatment. Each morning subjects completed a series of cognitive function tests and questionnaires to assess mood and multiple aspects of cognitive performance. We found that both ASV and supplemental oxygen (O2) improved daytime feelings of confusion (ASV: p < 0.01; O2: p < 0.05) and fatigue (ASV: p < 0.01; O2: p < 0.01) but did not improve other measures of cognitive performance at high altitude. However, performance improved on the trail making tests (TMT) A and B (p < 0.001), the balloon analog risk test (p < 0.0001), and the psychomotor vigilance test (p < 0.01) over the course of three days at altitude after controlling for effects of sleep treatments. Compared to sea level, subjects reported higher levels of confusion (p < 0.01) and performed worse on the TMT A (p < 0.05) and the emotion recognition test (p < 0.05) on nights when they received no treatment at high altitude. These results suggest that stabilizing breathing (ASV) or increasing oxygenation (supplemental oxygen) during sleep can reduce feelings of fatigue and confusion, but that daytime hypoxia may play a larger role in other cognitive impairments reported at high altitude. Furthermore, this study provides evidence that some aspects of cognition (executive control, risk inhibition, sustained attention) improve with acclimatization.
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Affiliation(s)
- Erica C. Heinrich
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Matea A. Djokic
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Dillon Gilbertson
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Pamela N. DeYoung
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Naa-Oye Bosompra
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Lu Wu
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Cecilia Anza-Ramirez
- Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Jeremy E. Orr
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Frank L. Powell
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Atul Malhotra
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Tatum S. Simonson
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of California San Diego, La Jolla, California, United States of America
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27
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Injury-Related Deaths according to Environmental, Demographic, and Lifestyle Factors. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2019; 2019:6942787. [PMID: 30944571 PMCID: PMC6421738 DOI: 10.1155/2019/6942787] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 01/29/2019] [Indexed: 01/22/2023]
Abstract
Background Environmental, demographic, and lifestyle variables have been associated with injury-related deaths. The current study identifies the simultaneous association of selected environmental, demographic, and lifestyle variables with deaths from homicide, unintentional injuries, and suicide. Materials and Methods Analyses are based on county-level mortality data in the contiguous United States, 2011–15. Basic summary statistics and Poisson regression were used to evaluate the data. Results The selected causes of death were impacted differently by age, sex, and race: for homicide, mortality rates were greater in ages 20–39, males, and blacks; for unintentional injuries, the rates increased with age, most noticeably in the oldest age group, and were highest among males and whites; and for suicide, the rates tended to increase with age and were greater in males and whites. Mortality rates from homicide were positively associated with poverty, cigarette smoking, air temperature, and leisure-time physical inactivity. They were negatively associated with precipitation and sunlight. Mortality rates from unintentional injuries were positively associated with altitude, cigarette smoking, air temperature, poverty, obesity, and precipitation. They were negatively associated with population density. Mortality rates from suicides were positively associated with altitude, cigarette smoking, obesity, air temperature, and precipitation and negatively associated with population density. Conclusion The results confirm and extend previous research in which death from homicide, unintentional injuries, and suicide are distinctly associated with a combination of environmental, demographic, and lifestyle variables. The findings may be useful in developing strategies for reducing injury-related deaths.
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28
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Abstract
Glucose is the long-established, obligatory fuel for brain that fulfills many critical functions, including ATP production, oxidative stress management, and synthesis of neurotransmitters, neuromodulators, and structural components. Neuronal glucose oxidation exceeds that in astrocytes, but both rates increase in direct proportion to excitatory neurotransmission; signaling and metabolism are closely coupled at the local level. Exact details of neuron-astrocyte glutamate-glutamine cycling remain to be established, and the specific roles of glucose and lactate in the cellular energetics of these processes are debated. Glycolysis is preferentially upregulated during brain activation even though oxygen availability is sufficient (aerobic glycolysis). Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in excess of oxygen, and adrenergic regulation of aerobic glycolysis draws attention to astrocytic metabolism, particularly glycogen turnover, which has a high impact on the oxygen-carbohydrate mismatch. Aerobic glycolysis is proposed to be predominant in young children and specific brain regions, but re-evaluation of data is necessary. Shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation, neurotransmission, and memory consolidation are controversial topics for which alternative mechanisms are proposed. Nutritional therapy and vagus nerve stimulation are translational bridges from metabolism to clinical treatment of diverse brain disorders.
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Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences , Little Rock, Arkansas ; and Department of Cell Biology and Physiology, University of New Mexico , Albuquerque, New Mexico
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29
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Bustamante-Sánchez Á, Delgado-Terán M, Clemente-Suárez VJ. Psychophysiological response of different aircrew in normobaric hypoxia training. ERGONOMICS 2019; 62:277-285. [PMID: 30101685 DOI: 10.1080/00140139.2018.1510541] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 07/20/2018] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Hypoxia remains the most important hazard in high altitude flights, but there is still a need for deeper analysis of the effect of hypoxia exposition in the psychophysiological and cognitive functions. The aim of this study was to study the effect of hypoxia training in cortical arousal, autonomic modulation, muscle strength and cognitive function. We analysed 23 male aircrew personnel of the Spanish Army and Air Force (10 Helicopter Pilots, 7 Transport Aircrew, 3 Transport Pilots and 3 F-18 Fighter Pilots) before, during and after a normobaric hypoxia exposition. Hypoxia produced an increase in perceived stress and effort, a higher Heart Rate and a decreased function of breath muscles. Working memory and pattern recognition were impaired after hypoxia exposition. Significant differences were found in cognitive tests performance among aircrew groups, suggesting differences on their previous training. These results can improve specific training for better preparation of pilots and aircrews for hypoxic threats. Practitioner summary: Distinct aircrew preparation produces a different hypoxia exposition effect on psychophysiological response and cognitive functions. Hypoxia produced an increase in Heart Rate, a decreased function of breath muscles, being more negatively affected in Transport Pilots. Cognition abilities were impaired after hypoxia exposition, independently of the aircrew group.
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Affiliation(s)
- Álvaro Bustamante-Sánchez
- a Department of Sport Science, Faculty of Sport Science , European University of Madrid , Madrid , Spain
| | | | - Vicente Javier Clemente-Suárez
- a Department of Sport Science, Faculty of Sport Science , European University of Madrid , Madrid , Spain
- b Study Centre in Applied Combat (CESCA) , Toledo , Spain
- c Grupo de Investigación en Cultura, Educación y Sociedad , Universidad de la Costa. Barranquilla , Colombia
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30
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Caris AV, Santos RVT. Performance and altitude: Ways that nutrition can help. Nutrition 2018; 60:35-40. [PMID: 30529882 DOI: 10.1016/j.nut.2018.09.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/29/2018] [Indexed: 12/18/2022]
Abstract
High altitudes are a challenge for human physiology and for sports enthusiasts. Several reasons lead to deterioration in performance at high altitudes. Hypoxia owing to high altitude causes a breakdown of homeostasis with imbalance in several physiological systems, including the immune system. The reduction in mucosal immunity and inflammation and the predominance of the humoral immune response causes a condition of immunosuppression and an increased likelihood of infection. In addition, it is known that worsening of the immune response is associated with reduced performance. On the other hand, immunonutrition plays an important role in modulating the effects of physical exercise on the immune system. However, to our knowledge, few studies have evaluated the effect of nutrition on the immune system after exercise in hypoxia. Although the association between exercise and hypoxia has been shown to be more severe for the body owing to the sum of stressful agents, supplementation with carbohydrates and glutamine seems to play a relevant role in mitigating immunosuppressive effects. These findings, although limited by the fact that they are the result of very few studies, shed light on a relevant theme for sports physiology and nutrition and suggest that both supplements may be useful for athletes, visitors, and workers in high-altitude regions. The aim of this review was to discuss the effects of high-altitude hypoxia on the human body from the point of view of exercise immunology because it is known that transient immunosuppression after strenuous exercise and competition should be followed by reduction in training overload and worse performance.
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Affiliation(s)
- Aline V Caris
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil
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31
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Pun M, Guadagni V, Bettauer KM, Drogos LL, Aitken J, Hartmann SE, Furian M, Muralt L, Lichtblau M, Bader PR, Rawling JM, Protzner AB, Ulrich S, Bloch KE, Giesbrecht B, Poulin MJ. Effects on Cognitive Functioning of Acute, Subacute and Repeated Exposures to High Altitude. Front Physiol 2018; 9:1131. [PMID: 30246787 PMCID: PMC6111975 DOI: 10.3389/fphys.2018.01131] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/30/2018] [Indexed: 01/12/2023] Open
Abstract
Objective: Neurocognitive functions are affected by high altitude, however the altitude effects of acclimatization and repeated exposures are unclear. We investigated the effects of acute, subacute and repeated exposure to 5,050 m on cognition among altitude-naïve participants compared to control subjects tested at low altitude. Methods: Twenty-one altitude-naïve individuals (25.3 ± 3.8 years, 13 females) were exposed to 5,050 m for 1 week (Cycle 1) and re-exposed after a week of rest at sea-level (Cycle 2). Baseline (BL, 520 m), acute (Day 1, HA1) and acclimatization (Day 6, HA6, 5,050 m) measurements were taken in both cycles. Seventeen control subjects (24.9 ± 2.6 years, 12 females) were tested over a similar period in Calgary, Canada (1,103 m). The Reaction Time (RTI), Attention Switching Task (AST), Rapid Visual Processing (RVP) and One Touch Stockings of Cambridge (OTS) tasks were administered and outcomes were expressed in milliseconds/frequencies. Lake Louise Score (LLS) and blood oxygen saturation (SpO2) were recorded. Results: In both cycles, no significant changes were found with acute exposure on the AST total score, mean latency and SD. Significant changes were found upon acclimatization solely in the altitude group, with improved AST Mean Latency [HA1 (588 ± 92) vs. HA6 (526 ± 91), p < 0.001] and Latency SD [HA1 (189 ± 86) vs. HA6 (135 ± 65), p < 0.001] compared to acute exposure, in Cycle 1. No significant differences were present in the control group. When entering Acute SpO2 (HA1-BL), Acclimatization SpO2 (HA6-BL) and LLS score as covariates for both cycles, the effects of acclimatization on AST outcomes disappeared indicating that the changes were partially explained by SpO2 and LLS. The changes in AST Mean Latency [ΔBL (−61.2 ± 70.2) vs. ΔHA6 (−28.0 ± 58), p = 0.005] and the changes in Latency SD [ΔBL (−28.4 ± 41.2) vs. ΔHA6 (−0.2235 ± 34.8), p = 0.007] across the two cycles were smaller with acclimatization. However, the percent changes did not differ between cycles. These results indicate independent effects of altitude across repeated exposures. Conclusions: Selective and sustained attention are impaired at altitude and improves with acclimatization.The observed changes are associated, in part, with AMS score and SpO2. The gains in cognition with acclimatization during a first exposure are not carried over to repeated exposures.
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Affiliation(s)
- Matiram Pun
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Veronica Guadagni
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,O'Brien Institute for Public Health, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Kaitlyn M Bettauer
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Psychology, Faculty of Science, University of British Columbia, Vancouver, BC, Canada
| | - Lauren L Drogos
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Julie Aitken
- Biomedical Engineering Graduate Program, University of Calgary, Calgary, AB, Canada
| | - Sara E Hartmann
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Michael Furian
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zürich, Zurich, Switzerland
| | - Lara Muralt
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zürich, Zurich, Switzerland
| | - Mona Lichtblau
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zürich, Zurich, Switzerland
| | - Patrick R Bader
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zürich, Zurich, Switzerland
| | - Jean M Rawling
- Department of Family Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Andrea B Protzner
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Psychology, Faculty of Arts, University of Calgary, Calgary, AB, Canada
| | - Silvia Ulrich
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zürich, Zurich, Switzerland
| | - Konrad E Bloch
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zürich, Zurich, Switzerland
| | - Barry Giesbrecht
- Department of Psychological and Brain Sciences, Institute for Collaborative Biotechnologies, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Marc J Poulin
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,O'Brien Institute for Public Health, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
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32
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Stavrou NAM, Debevec T, Eiken O, Mekjavic IB. Hypoxia Worsens Affective Responses and Feeling of Fatigue During Prolonged Bed Rest. Front Psychol 2018; 9:362. [PMID: 29628903 PMCID: PMC5876302 DOI: 10.3389/fpsyg.2018.00362] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/05/2018] [Indexed: 12/14/2022] Open
Abstract
Previous research, although limited, suggests that both hypoxia and bed rest influence psychological responses by exaggerating negative psychological responses and attenuating positive emotions. The present study investigated the effect of a 21-day prolonged exposure to normobaric hypoxia and bed rest on affective responses and fatigue. Eleven healthy participants underwent three 21-day interventions using a cross-over design: (1) normobaric hypoxic ambulatory confinement (HAMB), (2) normobaric hypoxic bed rest (HBR) and (3) normoxic bed rest (NBR). Affective and fatigue responses were investigated using the Activation Deactivation Adjective Check List, and the Multidimensional Fatigue Inventory, which were completed before (Pre), during (Day 7, Day 14, and Day 21) and after (Post) the interventions. The most negative psychological profile appeared during the HBR intervention. Specifically, tiredness, tension, general and physical fatigue significantly increased on days 7, 14, and 21, as well as at Post. After the HBR intervention, general and physical fatigue remained higher compared to Pre values. Additionally, a deterioration of psychological responses was also noted following HAMB and NBR. In particular, both hypoxia and BR per se induced subjective fatigue and negative affective responses. BR seems to exert a moderate negative effect on the sensation of fatigue, whereas exercise attenuates the negative effects of hypoxia as noted during the HAMB condition. In conclusion, our data suggest that the addition of hypoxia to bed rest-induced inactivity significantly worsens affective responses and feeling of fatigue.
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Affiliation(s)
- Nektarios A M Stavrou
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece.,Department of Sport Psychology, Hellenic Sports Research Institute, Olympic Athletic Center of Athens "Spiros Louis", Athens, Greece
| | - Tadej Debevec
- Department for Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of Technology, Stockholm, Sweden
| | - Igor B Mekjavic
- Department for Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
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33
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Stavrou NAM, Debevec T, Eiken O, Mekjavic IB. Hypoxia Exacerbates Negative Emotional State during Inactivity: The Effect of 21 Days Hypoxic Bed Rest and Confinement. Front Physiol 2018; 9:26. [PMID: 29472866 PMCID: PMC5809445 DOI: 10.3389/fphys.2018.00026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/09/2018] [Indexed: 11/13/2022] Open
Abstract
Hypoxia and confinement have both been shown to influence emotional state. It is envisaged that the inhabitants of future planetary habitats will be exposed to concomitant confinement, reduced gravity and hypoxia. We examined the independent and combined effects of a 21-day inactivity/unloading and normobaric hypoxia under confined conditions on various psychological factors. Eleven healthy men participated in three 21-day experimental campaigns designed in a cross-over manner: (1) Normobaric hypoxic ambulatory confinement, (2) Normobaric hypoxic bed rest and (3) Normobaric normoxic bed rest. The Profile of Mood States, and the Positive and Negative Affect Schedule were employed to assess the participants' psychological responses before (Pre), during (Day 7, Day 14, and Day 21) and after (Post) the confinements. The most negative psychological profile appeared on days 14 and 21 of the hypoxic bed rest campaign. A significant increase in depression, tension, and confusion was noted on days 14 and 21 of the hypoxic bed rest condition. Concomitantly, a decrease, albeit not statistically significant, in positive psychological responses was observed. The psychological profile returned to the initial level at Post following all confinements. These data suggest that the combined effect of hypoxia and bed rest induced the most negative effects on an individual's mood. However, significant intra- and inter-individual differences in psychological responses were noted and should be taken into consideration.
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Affiliation(s)
- Nektarios A. M. Stavrou
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
- Sport Psychology Department, Hellenic Sports Research Institute, Olympic Athletic Center of Athens “Spyros Louis”, Athens, Greece
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of Technology, Stockholm, Sweden
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
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34
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Karinen HM, Tuomisto MT. Performance, Mood, and Anxiety During a Climb of Mount Everest. High Alt Med Biol 2017; 18:400-410. [DOI: 10.1089/ham.2017.0033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Heikki M. Karinen
- Unit for Occupational Health, Faculty of Social Sciences, University of Tampere, Tampere, Finland
| | - Martti T. Tuomisto
- Faculty of Social Sciences (Psychology), University of Tampere, Tampere, Finland
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35
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Kang J, Ma X, He S. Evidence of high-altitude adaptation in the glyptosternoid fish, Creteuchiloglanis macropterus from the Nujiang River obtained through transcriptome analysis. BMC Evol Biol 2017; 17:229. [PMID: 29169322 PMCID: PMC5701497 DOI: 10.1186/s12862-017-1074-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 11/15/2017] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Organisms living at high altitudes face low oxygen and temperature conditions; thus, the genetic mechanisms underlying the adaptations in these organisms merit investigation. The glyptosternoid fish, Creteuchiloglanis macropterus mainly inhabits regions with gradual increases in altitudes along the Nujiang River and might serve as an appropriate evolutionary model for detecting adaptation processes in environments with altitude changes. RESULTS We constructed eleven RNA-sequencing (RNA-seq) libraries of C. macropterus collected from five locations at different altitudes to identify the genetic signatures of high-altitude adaptation. The comparative genomic analysis indicated that C. macropterus has an accelerated evolutionary rate compared with that of fishes in the lowland, and fishes at higher altitudes might evolve faster. Functional enrichment analysis of the fast-evolving and positively selected genes, differentially expressed genes and highly expressed genes, showed that these genes were involved in many functions related to energy metabolism and hypoxia. CONCLUSIONS Our study provides evidence of high-altitude adaptation in C. macropterus, and the detected adaptive genes might be a resource for future investigations of adaptations to high-altitude environments in other fishes.
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Affiliation(s)
- Jingliang Kang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Science, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072 China
- University of the Chinese Academy of Science, Beijing, China
| | - Xiuhui Ma
- College of Animal Science, Guizhou University, Guiyang, Guizhou 550025 China
| | - Shunping He
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Science, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072 China
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Willis SJ, Alvarez L, Millet GP, Borrani F. Changes in Muscle and Cerebral Deoxygenation and Perfusion during Repeated Sprints in Hypoxia to Exhaustion. Front Physiol 2017; 8:846. [PMID: 29163193 PMCID: PMC5671463 DOI: 10.3389/fphys.2017.00846] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 10/10/2017] [Indexed: 01/08/2023] Open
Abstract
During supramaximal exercise, exacerbated at exhaustion and in hypoxia, the circulatory system is challenged to facilitate oxygen delivery to working tissues through cerebral autoregulation which influences fatigue development and muscle performance. The aim of the study was to evaluate the effects of different levels of normobaric hypoxia on the changes in peripheral and cerebral oxygenation and performance during repeated sprints to exhaustion. Eleven recreationally active participants (six men and five women; 26.7 ± 4.2 years, 68.0 ± 14.0 kg, 172 ± 12 cm, 14.1 ± 4.7% body fat) completed three randomized testing visits in conditions of simulated altitude near sea-level (~380 m, FIO2 20.9%), ~2000 m (FIO2 16.5 ± 0.4%), and ~3800 m (FIO2 13.3 ± 0.4%). Each session began with a 12-min warm-up followed by two 10-s sprints and the repeated cycling sprint (10-s sprint: 20-s recovery) test to exhaustion. Measurements included power output, vastus lateralis, and prefrontal deoxygenation [near-infrared spectroscopy, delta (Δ) corresponds to the difference between maximal and minimal values], oxygen uptake, femoral artery blood flow (Doppler ultrasound), hemodynamic variables (transthoracic impedance), blood lactate concentration, and rating of perceived exertion. Performance (total work, kJ; −27.1 ± 25.8% at 2000 m, p < 0.01 and −49.4 ± 19.3% at 3800 m, p < 0.001) and pulse oxygen saturation (−7.5 ± 6.0%, p < 0.05 and −18.4 ± 5.3%, p < 0.001, respectively) decreased with hypoxia, when compared to 400 m. Muscle Δ hemoglobin difference ([Hbdiff]) and Δ tissue saturation index (TSI) were lower (p < 0.01) at 3800 m than at 2000 and 400 m, and lower Δ deoxyhemoglobin resulted at 3800 m compared with 2000 m. There were reduced changes in peripheral [Δ[Hbdiff], ΔTSI, Δ total hemoglobin ([tHb])] and greater changes in cerebral (Δ[Hbdiff], Δ[tHb]) oxygenation throughout the test to exhaustion (p < 0.05). Changes in cerebral deoxygenation were greater at 3800 m than at 2000 and 400 m (p < 0.01). This study confirms that performance in hypoxia is limited by continually decreasing oxygen saturation, even though exercise can be sustained despite maximal peripheral deoxygenation. There may be a cerebral autoregulation of increased perfusion accounting for the decreased arterial oxygen content and allowing for task continuation, as shown by the continued cerebral deoxygenation.
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Affiliation(s)
- Sarah J Willis
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Laurent Alvarez
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Grégoire P Millet
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Fabio Borrani
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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Billaut F, Gueit P, Faure S, Costalat G, Lemaître F. Do elite breath-hold divers suffer from mild short-term memory impairments? Appl Physiol Nutr Metab 2017; 43:247-251. [PMID: 29053942 DOI: 10.1139/apnm-2017-0245] [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: 11/22/2022]
Abstract
Repeated apneas are associated with severe hypoxemia that may ultimately lead to loss of consciousness in some breath-hold divers. Despite increasing number of practitioners, the relationship between apnea-induced hypoxia and neurocognitive functions is still poorly understood in the sport of free diving. To shed light onto this phenomenon, we examined the impact of long-term breath-hold diving training on attentional processing, short-term memory, and long-term mnesic and executive functions. Thirty-six men matched for age, height, and weight were separated into the following 3 groups: (i) 12 elite breath-hold divers (EBHD), mean static apnea best time 371 s, 105 months mean apnea experience; (ii) 12 novice breath-hold divers, mean best time 243 s, 8.75 months mean apnea experience; and (iii) 12 physical education students with no breath-hold diving experience; all of these participants performed varied written and computerized neuropsychological tasks. Compared with the 2 other groups, the EBHD group was slower to complete the interference card during a Stroop test (F[1,33] = 4.70, p < 0.05), and presented more errors on the interference card (F[1,33] = 2.96, p < 0.05) and a lower total interference score (F[1,33] = 5.64, p < 0.05). The time to complete the interference card test was positively correlated with maximal static apnea duration (r = 0.73, p < 0.05) and the number of years of breath-hold diving training (r = 0.79, p < 0.001). These findings suggest that breath-hold diving training over several years may cause mild, but persistent, short-term memory impairments.
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Affiliation(s)
- François Billaut
- a Département de kinésiologie, Faculté de Médecine, Université Laval, 2300, rue de la Terrasse, Québec, QC G1V 0A6, Canada
| | - Patrice Gueit
- b Centre d'Etudes des Transformations des Activités Physiques et Sportives, EA n°3832, Faculté des Sciences du Sport et de l'Education Physique de Rouen, Université de Rouen, Mont-Saint-Aignan 76130, France
| | - Sylvane Faure
- c Laboratoire d'Anthropologie et de Psychologie Cognitives et Sociales, EA 7278, Université Nice - Sophia-Antipolis, Nice 06357, France
| | - Guillaume Costalat
- d Laboratoire Adaptations Physiologiques à l'Exercice et Réadaptation à l'effort (APERE), EA n°3300, Université de Picardie Jules Verne, Amiens 80025, France
| | - Frédéric Lemaître
- b Centre d'Etudes des Transformations des Activités Physiques et Sportives, EA n°3832, Faculté des Sciences du Sport et de l'Education Physique de Rouen, Université de Rouen, Mont-Saint-Aignan 76130, France
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Phillips L, Basnyat B, Chang Y, Swenson ER, Harris NS. Findings of Cognitive Impairment at High Altitude: Relationships to Acetazolamide Use and Acute Mountain Sickness. High Alt Med Biol 2017; 18:121-127. [PMID: 28509579 DOI: 10.1089/ham.2016.0001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Phillips, Lara, Buddha Basnyat, Yuchiao Chang, Erik R. Swenson, and N. Stuart Harris. Findings of cognitive impairment at high altitude: relationships to acetazolamide use and acute mountain sickness. High Alt Med Biol. 18:121-127, 2017. OBJECTIVE Acute mountain sickness (AMS) is defined by patient-reported symptoms using the Lake Louise Score (LLS), which provides limited insight into any possible underlying central nervous system (CNS) dysfunction. Some evidence suggests AMS might coexist with altered neural functioning. Cognitive impairment (CI) may go undetected unless a sensitive test is applied. Our hypothesis was that a standardized test for mild CI would provide an objective measure of CNS dysfunction, which may correlate with the symptoms of AMS and so provide a potential new tool to better characterize altitude-related CNS dysfunction. We compared a cognitive screening tool with the LLS to see if it correlated with CNS dysfunction. METHODS Adult native English-speaking subjects visiting Himalayan Rescue Association aid stations in Nepal at 3520 m (11,548 ft) and 4550 m (14,927 ft) were recruited. Subjects were administered the LLS and a slightly modified version of the environmental Quick mild cognitive impairment screen (eQmci). Medication use for altitude illness was recorded. Scores were compared using the Spearman's correlation coefficient. Data also included medication use. RESULTS Seventy-nine subjects were enrolled. A cut-off of three or greater was used for the LLS to diagnose AMS and 67 or less for the eQmci to diagnose CI. There were 22 (28%) subjects who met criteria for AMS and 17 (22%) subjects who met criteria for CI. There was a weak correlation (r2 = 0.06, p = 0.04) between eQmci score and LLS. In matched subjects with identical LLS, recent acetazolamide use was associated with significantly more CI. CONCLUSION Field assessment of CI using a rapid standardized tool demonstrated that a substantial number of subjects were found to have mild CI following rapid ascent to 3520-4550 m (11,548-14,927 ft). The weak correlation between the LLS and eQmci suggests that AMS does not result in CI. Use of acetazolamide appears to be associated with CI at all levels of AMS severity.
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Affiliation(s)
- Lara Phillips
- 1 Division of Wilderness Medicine, Department of Emergency Medicine, Massachusetts General Hospital , Harvard Medical School, Boston, Massachusetts
| | - Buddha Basnyat
- 2 Oxford University Clinical Research Unit - Nepal , Himalayan Rescue Association, Kathmandu, Nepal
| | - Yuchiao Chang
- 1 Division of Wilderness Medicine, Department of Emergency Medicine, Massachusetts General Hospital , Harvard Medical School, Boston, Massachusetts
| | - Erik R Swenson
- 3 Medical Service, Veterans Affairs Puget Sound Health Care System, University of Washington , Seattle, Washington
| | - N Stuart Harris
- 1 Division of Wilderness Medicine, Department of Emergency Medicine, Massachusetts General Hospital , Harvard Medical School, Boston, Massachusetts
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Analysis of High-altitude Syndrome and the Underlying Gene Polymorphisms Associated with Acute Mountain Sickness after a Rapid Ascent to High-altitude. Sci Rep 2016; 6:38323. [PMID: 27982053 PMCID: PMC5159877 DOI: 10.1038/srep38323] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 11/08/2016] [Indexed: 11/08/2022] Open
Abstract
To investigated the objective indicators and potential genotypes for acute mountain sickness (AMS). 176 male subjects were evaluated for symptoms scores and physiological parameters at 3700 m. EPAS1 gene polymorphisms were explored and verified effects of potential genotypes on pulmonary function by inhaled budesonide. The incidence of AMS was 53.98% (95/176). The individuals who suffered from headache with anxiety and greater changes in heart rate (HR), the forced vital capacity (FVC), and mean flow velocity of basilar artery (Vm-BA), all of which were likely to develop AMS. The rs4953348 polymorphism of EPAS1 gene had a significant correlation with the SaO2 level and AMS, and a significant difference in the AG and GG genotype distribution between the AMS and non-AMS groups. The spirometric parameters were significantly lower, but HR (P = 0.036) and Vm-BA (P = 0.042) significantly higher in the AMS subjects with the G allele than those with the A allele. In summary, changes in HR (≥82 beats/min), FVC (≤4.2 Lt) and Vm-BA (≥43 cm/s) levels may serve as predictors for diagnosing AMS accompanied by high-altitude syndrome. The A allele of rs4953348 is a protective factor for AMS through HR and Vm-BA compensation, while the G allele may contribute to hypoxic pulmonary hypertension in AMS.
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Abstract
Scenic view at high altitude is a pleasure to the eyes, but it has some shortcoming effects as well. High altitude can be divided into different categories, i.e., high altitude (3000-5000 ft), very high altitude (5000-8000 ft), and extreme altitude (above 8000 ft). Much of the population resides at high altitude, and others go there for tourism. Military personnel are also posted there to defend boundaries. As we ascent to high altitude, partial pressure of oxygen reduces, whereas concentration remains the same; this reduces the availability of oxygen to different body parts. This pathophysiological condition is known as hypobaric hypoxia (HH) which leads to oxidative stress and further causes cognitive dysfunction in some cases. Hypoxia causes neurodegeneration in different brain regions; however, the hippocampus is found to be more prone in comparison to other brain regions. As the hippocampus is affected most, therefore, spatial memory is impaired most during such condition. This chapter will give a brief review of the damaging effect of high altitude on cognition and also throw light on possible herbal interventions at high altitude, which can improve cognitive performance as well as provide protection against the deteriorating effect of hypobaric hypoxia at high altitude.
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Affiliation(s)
- Vishal Jain
- Vallabhbhai Patel Chest Institute, Delhi University, Delhi, 110007, India.
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Donegani E, Paal P, Küpper T, Hefti U, Basnyat B, Carceller A, Bouzat P, van der Spek R, Hillebrandt D. Drug Use and Misuse in the Mountains: A UIAA MedCom Consensus Guide for Medical Professionals. High Alt Med Biol 2016; 17:157-184. [PMID: 27583821 DOI: 10.1089/ham.2016.0080] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Donegani, Enrico, Peter Paal, Thomas Küpper, Urs Hefti, Buddha Basnyat, Anna Carceller, Pierre Bouzat, Rianne van der Spek, and David Hillebrandt. Drug use and misuse in the mountains: a UIAA MedCom consensus guide for medical professionals. High Alt Med Biol. 17:157-184, 2016.-Aims: The aim of this review is to inform mountaineers about drugs commonly used in mountains. For many years, drugs have been used to enhance performance in mountaineering. It is the UIAA (International Climbing and Mountaineering Federation-Union International des Associations d'Alpinisme) Medcom's duty to protect mountaineers from possible harm caused by uninformed drug use. The UIAA Medcom assessed relevant articles in scientific literature and peer-reviewed studies, trials, observational studies, and case series to provide information for physicians on drugs commonly used in the mountain environment. Recommendations were graded according to criteria set by the American College of Chest Physicians. RESULTS Prophylactic, therapeutic, and recreational uses of drugs relevant to mountaineering are presented with an assessment of their risks and benefits. CONCLUSIONS If using drugs not regulated by the World Anti-Doping Agency (WADA), individuals have to determine their own personal standards for enjoyment, challenge, acceptable risk, and ethics. No system of drug testing could ever, or should ever, be policed for recreational climbers. Sponsored climbers or those who climb for status need to carefully consider both the medical and ethical implications if using drugs to aid performance. In some countries (e.g., Switzerland and Germany), administrative systems for mountaineering or medication control dictate a specific stance, but for most recreational mountaineers, any rules would be unenforceable and have to be a personal decision, but should take into account the current best evidence for risk, benefit, and sporting ethics.
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Affiliation(s)
- Enrico Donegani
- 1 Department of Cardiovascular Surgery, Sabah Al-Ahmed Cardiac Center , Al-Amiri Hospital, Kuwait, State of Kuwait
| | - Peter Paal
- 2 Department of Anaesthesiology and Critical Care Medicine, Innsbruck University Hospital , Innsbruck, Austria .,3 Department of Perioperative Medicine, Barts Heart Centre, St. Bartholomew's Hospital, Barts Health NHS Trust, Queen Mary University of London, London, United Kingdom .,4 Perioperative Medicine, St. Bartholomew's Hospital , London, United Kingdom
| | - Thomas Küpper
- 5 Institute of Occupational and Social Medicine, RWTH Aachen University , Aachen, Germany
| | - Urs Hefti
- 6 Department of Orthopedic and Trauma Surgery, Swiss Sportclinic , Bern, Switzerland
| | - Buddha Basnyat
- 7 Oxford University Clinical Research Unit-Nepal , Nepal International Clinic, and Himalayan Rescue, Kathmandu, Nepal
| | - Anna Carceller
- 8 Sports Medicine School, Instituto de Medicina de Montaña y del Deporte (IMMED), Federació d'Entitats Excursionistes (FEEC), University of Barcelona , Barcelona, Spain
| | - Pierre Bouzat
- 9 Department of Anesthesiology and Critical Care, University Hospital, INSERM U1236, Neuroscience Institute, Alps University, Grenoble, France
| | - Rianne van der Spek
- 10 Department of Endocrinology and Metabolism, Academic Medical Center Amsterdam, University of Amsterdam , Amsterdam, The Netherlands
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Association of Cognitive Performance with Time at Altitude, Sleep Quality, and Acute Mountain Sickness Symptoms. Wilderness Environ Med 2016; 27:371-8. [PMID: 27460198 DOI: 10.1016/j.wem.2016.04.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 04/25/2016] [Accepted: 04/25/2016] [Indexed: 11/21/2022]
Abstract
OBJECTIVE It is well documented that cognitive performance may be altered with ascent to altitude, but the association of various cognitive performance tests with symptoms of acute mountain sickness (AMS) is not well understood. Our objective was to assess and compare cognitive performance during a high-altitude expedition using several tests and to report the association of each test with AMS, headache, and quality of sleep. METHODS During an expedition to Mount Everest, 3 cognitive tests (Stroop, Trail Making, and the real-time cognitive assessment tool, an in-house developed motor accuracy test) were used along with a questionnaire to assess health and AMS. Eight team members were assessed pre-expedition, postexpedition, and at several time points during the expedition. RESULTS There were no significant differences (P >.05) found among scores taken at 3 time points at base camp and the postexpedition scores for all 3 tests. Changes in the Stroop test scores were significantly associated with the odds of AMS (P <.05). The logistic regression results show that the percent change from baseline for Stroop score (β = -5.637; P = .032) and Stroop attempts (β = -5.269; P = .049) are significantly associated with the odds of meeting the criteria for AMS. CONCLUSIONS No significant changes were found in overall cognitive performance at altitude, but a significant relationship was found between symptoms of AMS and performance in certain cognitive tests. This research shows the need for more investigation of objective physiologic assessments to associate with self-perceived metrics of AMS to gauge effect on cognitive performance.
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West JB. Cognitive Impairment of School Children at High Altitude: The Case for Oxygen Conditioning in Schools. High Alt Med Biol 2016; 17:203-207. [PMID: 27355278 DOI: 10.1089/ham.2016.0026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
West, John B. Cognitive impairment of school children at high altitude: the case for oxygen conditioning in schools. High Alt Med Biol. 17:203-207, 2016.-The hypoxia of high altitude frequently affects cognitive function. Recent work has shown that high altitude impairs the neuropsychological function of children of school age when compared with a similar control group of children at low altitude. This implies that the learning process is compromised at high altitude. One option is to bus children down to a lower altitude for schooling, but this is generally impracticable. Recently the new technique of oxygen conditioning has been introduced. The procedure is similar to air conditioning except that instead of altering the temperature of the air, the oxygen concentration is increased, thus raising the PO2 in the inspired air of classrooms. The result is that the children are physiologically at a lower altitude. Just as in very hot or cold climates, it is now unacceptable to have schools that are not air conditioned; in the future the same may apply to schools at high altitude that are not oxygen conditioned.
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Affiliation(s)
- John B West
- Department of Medicine, University of California San Diego , La Jolla, California
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Goldstein G, He J, Ruthven L, Walker J. An introduction to the Ruthven Impairment Assessment (RIA): A stability study. APPLIED NEUROPSYCHOLOGY-ADULT 2016; 23:302-8. [PMID: 26943004 DOI: 10.1080/23279095.2015.1079715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The Ruthven Impairment Assessment (RIA) is introduced as a new neurocognitive test for the evaluation of complex attentional, reasoning, and working-memory abilities. It contains 5 subtests and is administered by computer within 15 min. The subtests include measures of simple and complex attention, working memory, sequential reasoning, and problem-solving abilities. A clock is presented on the computer screen and the participant is instructed to use the space bar or a mouse to respond to the test items. Scores include reaction time and accuracy measures. The present study evaluates the stability of the RIA in healthy, normal individuals by repeating the procedure 3 times and comparing performance with analyses of variance (ANOVAs). The ANOVA results with 1 exception were nonsignificant, indicating that the RIA scores are stable in normal individuals and do not fluctuate significantly across testing.
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Affiliation(s)
- Gerald Goldstein
- a Mental Illness Research, Educational, and Clinical Center , VA Pittsburgh Healthcare System , Pittsburgh , Pennsylvania
| | - Jibo He
- b Department of Psychology , Wichita State University , Wichita , Kansas
| | | | - Jon Walker
- d Research Service, VA Pittsburgh Healthcare System , Pittsburgh , Pennsylvania
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Chen J, Fan C, Li J, Han Q, Lin J, Yang T, Zhang J. Increased Intraregional Synchronized Neural Activity in Adult Brain After Prolonged Adaptation to High-Altitude Hypoxia: A Resting-State fMRI Study. High Alt Med Biol 2016; 17:16-24. [PMID: 26906285 DOI: 10.1089/ham.2015.0104] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The human brain is intrinsically plastic such that its functional architecture can be reorganized in response to environmental pressures and physiological changes. However, it remains unclear whether a compensatory modification of spontaneous neural activity occurs in adult brain during prolonged high-altitude (HA) adaptation. In this study, we obtained resting-state functional magnetic resonance (MR) images in 16 adults who have immigrated to Qinghai-Tibet Plateau (2300-4400 m) for 2 years and in 16 age-matched sea level (SL) controls. A validated regional homogeneity (Reho) method was employed to investigate the local synchronization of resting-state functional magnetic resonance imaging (fMRI) signals. Seed connectivity analysis was carried out subsequently. Cognitive and physiological assessments were made and correlated with the image metrics. Compared with SL controls, global mean Reho was significantly increased in HA immigrants as well as a regional increase in the right inferolateral sensorimotor cortex. Furthermore, mean z-Reho value extracted within the inferolateral sensorimotor area showed trend-level significant inverse correlation with memory search reaction time in HA immigrants. These observations, for the first time, provide evidence of adult brain resilience of spontaneous neural activity after long-term HA exposure without inherited and developmental effects. Resting-state fMRI could yield valuable information for central mechanisms underlying respiratory and cognitive compensations in adults during prolonged environmentally hypoxic adaptation, paving the way for future HA-adaptive training.
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Affiliation(s)
- Ji Chen
- 1 Department of Physiology and Neurobiology, Medical College of Xiamen University , Xiamen, Fujian, China .,2 Department of Medical Imaging Center, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA , Fuzhou, Fujian, China
| | - Cunxiu Fan
- 1 Department of Physiology and Neurobiology, Medical College of Xiamen University , Xiamen, Fujian, China
| | - Jinqiang Li
- 3 Department of Clinical Psychology, Gulangyu Sanatorium of PLA , Xiamen, Fujian, China
| | - Qiaoqing Han
- 3 Department of Clinical Psychology, Gulangyu Sanatorium of PLA , Xiamen, Fujian, China
| | - Jianzhong Lin
- 4 Magnetic Resonance Center, Zhongshan Hospital, Medical College of Xiamen University , Xiamen, Fujian, China
| | - Tianhe Yang
- 4 Magnetic Resonance Center, Zhongshan Hospital, Medical College of Xiamen University , Xiamen, Fujian, China
| | - Jiaxing Zhang
- 1 Department of Physiology and Neurobiology, Medical College of Xiamen University , Xiamen, Fujian, China
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Swenson ER. Hypoxia and Its Acid-Base Consequences: From Mountains to Malignancy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 903:301-23. [PMID: 27343105 DOI: 10.1007/978-1-4899-7678-9_21] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hypoxia, depending upon its magnitude and circumstances, evokes a spectrum of mild to severe acid-base changes ranging from alkalosis to acidosis, which can alter many responses to hypoxia at both non-genomic and genomic levels, in part via altered hypoxia-inducible factor (HIF) metabolism. Healthy people at high altitude and persons hyperventilating to non-hypoxic stimuli can become alkalotic and alkalemic with arterial pH acutely rising as high as 7.7. Hypoxia-mediated respiratory alkalosis reduces sympathetic tone, blunts hypoxic pulmonary vasoconstriction and hypoxic cerebral vasodilation, and increases hemoglobin oxygen affinity. These effects and others can be salutary or counterproductive to tissue oxygen delivery and utilization, based upon magnitude of each effect and summation. With severe hypoxia either in the setting of profound arterial hemoglobin desaturation and reduced O2 content or poor perfusion (ischemia) at the global or local level, metabolic and hypercapnic acidosis develop along with considerable lactate formation and pH falling to below 6.8. Although conventionally considered to be injurious and deleterious to cell function and survival, both acidoses may be cytoprotective by various anti-inflammatory, antioxidant, and anti-apoptotic mechanisms which limit total hypoxic or ischemic-reperfusion injury. Attempts to correct acidosis by giving bicarbonate or other alkaline agents under these circumstances ahead of or concurrent with reoxygenation efforts may be ill advised. Better understanding of this so-called "pH paradox" or permissive acidosis may offer therapeutic possibilities. Rapidly growing cancers often outstrip their vascular supply compromising both oxygen and nutrient delivery and metabolic waste disposal, thus limiting their growth and metastatic potential. However, their excessive glycolysis and lactate formation may not necessarily represent oxygen insufficiency, but rather the Warburg effect-an attempt to provide a large amount of small carbon intermediates to supply the many synthetic pathways of proliferative cell growth. In either case, there is expression and upregulation of many genes involved in acid-base homeostasis, in part by HIF-1 signaling. These include a unique isoform of carbonic anhydrase (CA-IX) and numerous membrane acid-base transporters engaged to maintain an optimal intracellular and extracellular pH for maximal growth. Inhibition of these proteins or gene suppression may have important therapeutic application in cancer chemotherapy.
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Affiliation(s)
- Erik R Swenson
- Pulmonary and Critical Care Medicine, Department of Medicine, University of Washington, Seattle, WA, USA. .,Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA. .,VA Puget Sound Health Care System, University of Washington, Seattle, WA, USA.
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Sakamoto T. Current status of brain protection during surgery for congenital cardiac defect. Gen Thorac Cardiovasc Surg 2015; 64:72-81. [PMID: 26620539 DOI: 10.1007/s11748-015-0606-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Indexed: 10/22/2022]
Abstract
The long-term neurodevelopmental outcome has been a great concern for cardiac surgeons although it is still unclear. There are some risks regarding the neurological and neuropsychological deficits before, during and after cardiovascular surgery. Current status of brain protection during congenital heart surgery could be reported. The incidence of neurologic outcome and the appropriate CPB strategy for brain protection are stated, and the latest data of neurodevelopmental outcome after pediatric cardiac surgery are clarified.
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Affiliation(s)
- Takahiko Sakamoto
- Division of Pediatric Cardiovascular Surgery, Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
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Abstract
Dull and hypoxic brains have been a frequent subject in the medical and mountaineering literature. Deterioration of cognitive and other neurological function occurs at high altitude, with or without high altitude cerebral edema. This historical essay explores a 2014 first-ever English translation of cerebral blood flow studies by nineteenth century physiologist Angelo Mosso. Some of the medical history and physiology of brain function is discussed, but much of the style focuses on quotations from the writings of mountaineers and mountaineering physicians to provide color commentary about dull brains at high altitude.
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50
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Silva-Urra JA, Núñez-Espinosa CA, Niño-Mendez OA, Gaitán-Peñas H, Altavilla C, Toro-Salinas A, Torrella JR, Pagès T, Javierre CF, Behn C, Viscor G. Circadian and Sex Differences After Acute High-Altitude Exposure: Are Early Acclimation Responses Improved by Blue Light? Wilderness Environ Med 2015; 26:459-71. [PMID: 26254125 DOI: 10.1016/j.wem.2015.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 04/30/2015] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE The possible effects of blue light during acute hypoxia and the circadian rhythm on several physiological and cognitive parameters were studied. METHODS Fifty-seven volunteers were randomly assigned to 2 groups: nocturnal (2200-0230 hours) or diurnal (0900-1330 hours) and exposed to acute hypoxia (4000 m simulated altitude) in a hypobaric chamber. The participants were illuminated by blue LEDs or common artificial light on 2 different days. During each session, arterial oxygen saturation (Spo2), blood pressure, heart rate variability, and cognitive parameters were measured at sea level, after reaching the simulated altitude of 4000 m, and after 3 hours at this altitude. RESULTS The circadian rhythm caused significant differences in blood pressure and heart rate variability. A 4% to 9% decrease in waking nocturnal Spo2 under acute hypoxia was observed. Acute hypoxia also induced a significant reduction (4%-8%) in systolic pressure, slightly more marked (up to 13%) under blue lighting. Women had significantly increased systolic (4%) and diastolic (12%) pressures under acute hypoxia at night compared with daytime pressure; this was not observed in men. Some tendencies toward better cognitive performance (d2 attention test) were seen under blue illumination, although when considered together with physiological parameters and reaction time, there was no conclusive favorable effect of blue light on cognitive fatigue suppression after 3 hours of acute hypobaric hypoxia. CONCLUSIONS It remains to be seen whether longer exposure to blue light under hypobaric hypoxic conditions would induce favorable effects against fatigue.
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Affiliation(s)
- Juan A Silva-Urra
- Departamento Biomédico, Universidad de Antofagasta, Antofagasta, Chile
| | | | - Oscar A Niño-Mendez
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, Barcelona, Spain
| | | | | | | | | | | | - Casimiro F Javierre
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, Barcelona, Spain
| | - Claus Behn
- Laboratorio de Ambientes Extremos (ICBM), Universidad de Chile, Santiago de Chile, Chile
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