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Reiser AE, Furian M, Lichtblau M, Buergin A, Schneider SR, Appenzeller P, Mayer L, Muralt L, Mademilov M, Abdyraeva A, Aidaralieva S, Muratbekova A, Akylbekov A, Sheraliev U, Shabykeeva S, Sooronbaev TM, Ulrich S, Bloch KE. Effect of acetazolamide on visuomotor performance at high altitude in healthy people 40 years of age or older-RCT. PLoS One 2023; 18:e0280585. [PMID: 36662903 PMCID: PMC9858039 DOI: 10.1371/journal.pone.0280585] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/04/2023] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE Altitude travel is increasingly popular also for middle-aged and older tourists and professionals. Due to the sensitivity of the central nervous system to hypoxia, altitude exposure may impair visuomotor performance although this has not been extensively studied. Therefore, we investigated whether a sojourn at moderately high altitude is associated with visuomotor performance impairments in healthy adults, 40y of age or older, and whether this adverse altitude-effect can be prevented by acetazolamide, a drug used to prevent acute mountain sickness. METHODS In this randomized placebo-controlled parallel-design trial, 59 healthy lowlanders, aged 40-75y, were assigned to acetazolamide (375 mg/day, n = 34) or placebo (n = 25), administered one day before ascent and while staying at high altitude (3100m). Visuomotor performance was assessed at 760m and 3100m after arrival and in the next morning (post-sleep) by a computer-assisted test (Motor-Task-Manager). It quantified deviation of a participant-controlled cursor affected by rotation during target tracking. Primary outcome was the directional error during post-sleep recall of adaptation to rotation estimated by multilevel linear regression modeling. Additionally, adaptation, immediate recall, and correct test execution were evaluated. RESULTS Compared to 760m, assessments at 3100m with placebo revealed a mean (95%CI) increase in directional error during adaptation and immediate recall by 1.9° (0.2 to 3.5, p = 0.024) and 1.1° (0.4 to 1.8, p = 0.002), respectively. Post-sleep recall remained unchanged (p = NS), however post-sleep correct test execution was 14% less likely (9 to 19, p<0.001). Acetazolamide improved directional error during post-sleep recall by 5.6° (2.6 to 8.6, p<0.001) and post-sleep probability of correct test execution by 36% (30 to 42, p<0.001) compared to placebo. CONCLUSION In healthy individuals, 40y of age or older, altitude exposure impaired adaptation to and immediate recall and correct execution of a visuomotor task. Preventive acetazolamide treatment improved visuomotor performance after one night at altitude and increased the probability of correct test execution compared to placebo. CLINICALTRIALS.GOV IDENTIFIER ClinicalTrials.gov NCT03536520.
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Affiliation(s)
- Aurelia E. Reiser
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Aline Buergin
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Simon R. Schneider
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Paula Appenzeller
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Laura Mayer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Lara Muralt
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Maamed Mademilov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ainura Abdyraeva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Shoira Aidaralieva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Aibermet Muratbekova
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Azamat Akylbekov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ulan Sheraliev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Saltanat Shabykeeva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Talant M. Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Konrad E. Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
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Shao Q, Liu J, Li G, Gu Y, Guo M, Guan Y, Tian Z, Ma W, Wang C, Ji X. Proteomic Analysis Reveals That Mitochondria Dominate the Hippocampal Hypoxic Response in Mice. Int J Mol Sci 2022; 23:ijms232214094. [PMID: 36430571 PMCID: PMC9697535 DOI: 10.3390/ijms232214094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/10/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022] Open
Abstract
Hypoxic stress occurs in various physiological and pathological states, such as aging, disease, or high-altitude exposure, all of which pose a challenge to many organs in the body, necessitating adaptation. However, the exact mechanisms by which hypoxia affects advanced brain function (learning and memory skills in particular) remain unclear. In this study, we investigated the effects of hypoxic stress on hippocampal function. Specifically, we studied the effects of the dysfunction of mitochondrial oxidative phosphorylation using global proteomics. First, we found that hypoxic stress impaired cognitive and motor abilities, whereas it caused no substantial changes in the brain morphology or structure of mice. Second, bioinformatics analysis indicated that hypoxia affected the expression of 516 proteins, of which 71.1% were upregulated and 28.5% were downregulated. We demonstrated that mitochondrial function was altered and manifested as a decrease in NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4 expression, accompanied by increased reactive oxygen species generation, resulting in further neuronal injury. These results may provide some new insights into how hypoxic stress alters hippocampal function via the dysfunction of mitochondrial oxidative phosphorylation.
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Affiliation(s)
- Qianqian Shao
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
| | - Jia Liu
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
| | - Gaifen Li
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yakun Gu
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
| | - Mengyuan Guo
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
| | - Yuying Guan
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Zhengming Tian
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
| | - Wei Ma
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
| | - Chaoyu Wang
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
| | - Xunming Ji
- Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing 100069, China
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
- Correspondence: ; Tel.: +86-139-1107-7166
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Scheiwiller PM, Furian M, Buergin A, Mayer LC, Schneider SR, Mademilov M, Lichtblau M, Muralt L, Sheraliev U, Sooronbaev TM, Ulrich S, Bloch KE. Visuomotor performance at high altitude in COPD patients. Randomized placebo-controlled trial of acetazolamide. Front Physiol 2022; 13:980755. [PMID: 36160864 PMCID: PMC9493049 DOI: 10.3389/fphys.2022.980755] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction: We evaluated whether exposure to high altitude impairs visuomotor learning in lowlanders with chronic obstructive pulmonary disease (COPD) and whether this can be prevented by acetazolamide treatment.Methods: 45 patients with COPD, living <800 m, FEV1 ≥40 to <80%predicted, were randomized to acetazolamide (375 mg/d) or placebo, administered 24h before and during a 2-day stay in a clinic at 3100 m. Visuomotor performance was evaluated with a validated, computer-assisted test (Motor-Task-Manager) at 760 m above sea level (baseline, before starting the study drug), within 4h after arrival at 3100 m and in the morning after one night at 3100 m. Main outcome was the directional error (DE) of cursor movements controlled by the participant via mouse on a computer screen during a target tracking task. Effects of high altitude and acetazolamide on DE during an adaptation phase, immediate recall and post-sleep recall were evaluated by regression analyses. www.ClinicalTrials.gov NCT03165890.Results: In 22 patients receiving placebo, DE at 3100 m increased during adaptation by mean 2.5°, 95%CI 2.2° to 2.7° (p < 0.001), during immediate recall by 5.3°, 4.6° to 6.1° (p < 0.001), and post-sleep recall by 5.8°, 5.0 to 6.7° (p < 0.001), vs. corresponding values at 760 m. In 23 participants receiving acetazolamide, corresponding DE were reduced by −0.3° (−0.6° to 0.1°, p = 0.120), −2.7° (−3.7° to −1.6°, p < 0.001) and −3.1° (−4.3° to −2.0°, p < 0.001), compared to placebo at 3100 m.Conclusion: Lowlanders with COPD travelling to 3100 m experienced altitude-induced impairments in immediate and post-sleep recall of a visuomotor task. Preventive acetazolamide treatment mitigated these undesirable effects.
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Affiliation(s)
- P. M. Scheiwiller
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - M. Furian
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - A. Buergin
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - L. C. Mayer
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - S. R. Schneider
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - M. Mademilov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Department of Respiratory Medicine, Bishkek, Kyrgyz Republic
| | - M. Lichtblau
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - L. Muralt
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - U. Sheraliev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Department of Respiratory Medicine, Bishkek, Kyrgyz Republic
| | - T. M. Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Department of Respiratory Medicine, Bishkek, Kyrgyz Republic
| | - S. Ulrich
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - K. E. Bloch
- University Hospital of Zurich, Department of Respiratory Medicine, Sleep Disorders Center, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- *Correspondence: K. E. Bloch,
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Li T, Tan L, Furian M, Zhang Y, Luo L, Lei F, Xue X, He J, Tang X. Sex-Specific Difference in the Effect of Altitude on Sleep and Nocturnal Breathing in Young Healthy Volunteers. J Clin Med 2022; 11:jcm11102869. [PMID: 35628996 PMCID: PMC9143383 DOI: 10.3390/jcm11102869] [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: 03/22/2022] [Revised: 05/05/2022] [Accepted: 05/16/2022] [Indexed: 02/05/2023] Open
Abstract
Importance: To date, there is no established evidence of sex-specific differences in altitude-induced sleep-disordered breathing (SDB) during polysomnography-confirmed sleep. Objective: The aim of this study was to investigate whether differences in sex play a pivotal role in incidences of SDB and acute mountain sickness (AMS) when staying overnight at high altitude. Design: This was a prospective cohort study. Setting: Participants underwent overnight polysomnography (PSG) and clinical assessment in a sleep laboratory at 500 m and two consecutive days at 3270 m. Participants: The participants comprised 28 (18 women) healthy, young, low-altitude residents with a median (interquartile range) age of 26.0 (25.0, 28.0) years. Exposures: Altitude exposure. Main outcomes and Measures: The primary outcome was altitude-induced change in the PSG-confirmed apnea−hypopnea index (AHI) at 3270 m compared to 500 m between men and women. Secondary outcomes included sex differences in other parameters related to SDB, sleep structure, AMS, psychomotor vigilance test reaction time and parameters from arterial and venous blood analyses. Results: The median (interquartile range) AHIs at 500 m and 3270 m on night 1 and on night 2 were 6.5/h (3.6, 9.1), 23.7/h (16.2, 42.5) and 15.2/h (11.8, 20.9) in men, respectively, and 2.2/h (1.0, 5.5), 8.0/h (5.3, 17.0) and 7.1/h (4.9, 11.5) in women, respectively (p < 0.05 nights 1 and 2 at 3270 m vs. 500 m in men and women). The median difference (95% CI) of altitude-induced change in AHI (3270 m night 1 compared to 500 m) between men and women was 11.2/h (1.9 to 19.6) (p < 0.05). Over the time course of 2 days at 3270 m, 9 out of 18 (50%) women and 1 out of 10 (10%) men developed AMS (p < 0.05 women versus men). Conclusions and Relevance: This prospective cohort study showed that men were more susceptible to altitude-induced SDB but that they had a lower AMS incidence when staying for 2 days at 3270 m than women. These findings indicate that sex-related prevention and intervention strategies against SDB and AMS are highly warranted. Trial Registration: This trial was registered at the Chinese Clinical Trial Registry; No. ChiCTR1800020155.
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Affiliation(s)
- Taomei Li
- Sleep Medicine Center, Mental Health Center, Department of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; (T.L.); (L.T.); (Y.Z.); (L.L.); (F.L.)
| | - Lu Tan
- Sleep Medicine Center, Mental Health Center, Department of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; (T.L.); (L.T.); (Y.Z.); (L.L.); (F.L.)
| | - Michael Furian
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, 8091 Zurich, Switzerland;
| | - Yanyan Zhang
- Sleep Medicine Center, Mental Health Center, Department of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; (T.L.); (L.T.); (Y.Z.); (L.L.); (F.L.)
| | - Lian Luo
- Sleep Medicine Center, Mental Health Center, Department of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; (T.L.); (L.T.); (Y.Z.); (L.L.); (F.L.)
| | - Fei Lei
- Sleep Medicine Center, Mental Health Center, Department of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; (T.L.); (L.T.); (Y.Z.); (L.L.); (F.L.)
| | - Xiaofang Xue
- Department of Cardiology, Diqing Tibetan Autonomous Prefectural People’s Hospital, Shangri-La 674400, China; (X.X.); (J.H.)
| | - Jiaming He
- Department of Cardiology, Diqing Tibetan Autonomous Prefectural People’s Hospital, Shangri-La 674400, China; (X.X.); (J.H.)
| | - Xiangdong Tang
- Sleep Medicine Center, Mental Health Center, Department of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China; (T.L.); (L.T.); (Y.Z.); (L.L.); (F.L.)
- Correspondence: ; Tel.: +86-28-85422733; Fax: +86-28-85422632
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Burtscher J, Mallet RT, Burtscher M, Millet GP. Hypoxia and brain aging: Neurodegeneration or neuroprotection? Ageing Res Rev 2021; 68:101343. [PMID: 33862277 DOI: 10.1016/j.arr.2021.101343] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 12/12/2022]
Abstract
The absolute reliance of the mammalian brain on oxygen to generate ATP renders it acutely vulnerable to hypoxia, whether at high altitude or in clinical settings of anemia or pulmonary disease. Hypoxia is pivotal to the pathogeneses of myriad neurological disorders, including Alzheimer's, Parkinson's and other age-related neurodegenerative diseases. Conversely, reduced environmental oxygen, e.g. sojourns or residing at high altitudes, may impart favorable effects on aging and mortality. Moreover, controlled hypoxia exposure may represent a treatment strategy for age-related neurological disorders. This review discusses evidence of hypoxia's beneficial vs. detrimental impacts on the aging brain and the molecular mechanisms that mediate these divergent effects. It draws upon an extensive literature search on the effects of hypoxia/altitude on brain aging, and detailed analysis of all identified studies directly comparing brain responses to hypoxia in young vs. aged humans or rodents. Special attention is directed toward the risks vs. benefits of hypoxia exposure to the elderly, and potential therapeutic applications of hypoxia for neurodegenerative diseases. Finally, important questions for future research are discussed.
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Affiliation(s)
- Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland; Institute of Sport Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland.
| | - Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland
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Bloch KE, Buenzli JC, Latshang TD, Ulrich S. Sleep at high altitude: guesses and facts. J Appl Physiol (1985) 2015; 119:1466-80. [PMID: 26229000 DOI: 10.1152/japplphysiol.00448.2015] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 07/13/2015] [Indexed: 11/22/2022] Open
Abstract
Lowlanders commonly report a poor sleep quality during the first few nights after arriving at high altitude. Polysomnographic studies reveal that reductions in slow wave sleep are the most consistent altitude-induced changes in sleep structure identified by visual scoring. Quantitative spectral analyses of the sleep electroencephalogram have confirmed an altitude-related reduction in the low-frequency power (0.8-4.6 Hz). Although some studies suggest an increase in arousals from sleep at high altitude, this is not a consistent finding. Whether sleep instability at high altitude is triggered by periodic breathing or vice versa is still uncertain. Overnight changes in slow wave-derived encephalographic measures of neuronal synchronization in healthy subjects were less pronounced at moderately high (2,590 m) compared with low altitude (490 m), and this was associated with a decline in sleep-related memory consolidation. Correspondingly, exacerbation of breathing and sleep disturbances experienced by lowlanders with obstructive sleep apnea during a stay at 2,590 m was associated with poor performance in driving simulator tests. These findings suggest that altitude-related alterations in sleep may adversely affect daytime performance. Despite recent advances in our understanding of sleep at altitude, further research is required to better establish the role of gender and age in alterations of sleep at different altitudes, to determine the influence of acclimatization and of altitude-related illness, and to uncover the characteristics of sleep in highlanders that may serve as a study paradigm of sleep in patients exposed to chronic hypoxia due to cardiorespiratory disease.
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Affiliation(s)
- Konrad E Bloch
- Sleep Disorders Center, Pulmonary Division, University Hospital of Zurich, Zurich; Switzerland; Zurich Center for Human Integrative Physiology, University of Zurich, Zurich, Switzerland; and Zurich Center for Interdisciplinary Sleep Research, University of Zurich, Zurich, Switzerland
| | - Jana C Buenzli
- Sleep Disorders Center, Pulmonary Division, University Hospital of Zurich, Zurich; Switzerland
| | - Tsogyal D Latshang
- Sleep Disorders Center, Pulmonary Division, University Hospital of Zurich, Zurich; Switzerland; Zurich Center for Interdisciplinary Sleep Research, University of Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Sleep Disorders Center, Pulmonary Division, University Hospital of Zurich, Zurich; Switzerland; Zurich Center for Human Integrative Physiology, University of Zurich, Zurich, Switzerland; and
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