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Sevik A, Gaisl T, Forrer A, Graf L, Ulrich S, Bloch KE, Lichtblau M, Furian M. High altitudes and partial pressure of arterial oxygen in patients with chronic obstructive pulmonary disease - A systematic review and meta-analysis. Pulmonology 2024:S2531-0437(24)00095-3. [PMID: 39030093 DOI: 10.1016/j.pulmoe.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 05/13/2024] [Accepted: 06/04/2024] [Indexed: 07/21/2024] Open
Abstract
IMPORTANCE Prior study in healthy subjects has shown a reduction of partial pressure of arterial oxygen (PaO2) by -1.60 kPa/kilometre of altitude gain. However, the association of altitude-related change in PaO2 and altitude-related adverse health effects (ARAHE) in patients with chronic obstructive pulmonary disease (COPD) remain unknown. OBJECTIVE To provide an effect size estimate for the decline in PaO2 with each kilometre of altitude gain and to identify ARAHE in relation to altitude in patients with COPD. www.crd.york.ac.uk/prospero: CRD42020217938. DATA SOURCES A systematic search of PubMed and Embase was performed from inception to May 30, 2023. STUDY SELECTION Peer-reviewed and prospective studies in patients with COPD staying at altitudes >1500 m providing arterial blood gases within the first 3 days at the target altitude. DATA EXTRACTION AND SYNTHESIS Aggregate data (AD) on study characteristics were extracted, and individual patient data (IPD) were requested. Estimates were pooled using random-effects meta-analysis. MAIN OUTCOME AND MEASURES Relative risk estimates and 95 % confidence intervals for the association between PaO2 and altitude in patients with COPD. RESULTS Thirteen studies were included in the AD analysis, of which 6 studies (222 patients, 45.2 % female) provided IPD, thus were included in the quantitative analysis. The estimated effect size of PaO2 was -0.84 kPa [95 %CI, -0.92 to -0.76] per 1000 m of altitude gain (I2=65.0 %, P < 0.001). In multivariable regression analysis, COPD severity, baseline PaO2, age and time spent at altitude were predictors for PaO2 at altitude. Overall, 37.8 % of COPD patients experienced an ARAHE, whereas older age, female sex, COPD severity, baseline PaO2, and target altitude were predictors for the occurrence of ARAHE (area under ROC curve: 0.9275, P < 0.001). CONCLUSIONS AND RELEVANCE This meta-analysis, providing altitude-related decrease in PaO2 and risk of ARAHE in patients with COPD ascending to altitudes >1500 m, revealed a lower altitude-related decrease in PaO2 in COPD patients compared with healthy. However, these findings might improve patient care and facilitate decisions about initiating preventive measures against hypoxaemia and ARAHE in patients with COPD planning an altitude sojourn or intercontinental flight, i.e. supplemental oxygen or acetazolamide.
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Affiliation(s)
- A Sevik
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - T Gaisl
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - A Forrer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - L Graf
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - S Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Bishkek, Switzerland, Kyrgyz Republic
| | - K E Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Bishkek, Switzerland, Kyrgyz Republic
| | - M Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Bishkek, Switzerland, Kyrgyz Republic
| | - M Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Bishkek, Switzerland, Kyrgyz Republic; Research Department, Swiss University for Traditional Chinese Medicine, Bad Zurzach, Switzerland.
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Trammer RA, Rooney D, Benderoth S, Wittkowski M, Wenzel J, Elmenhorst EM. Effects of moderate alcohol consumption and hypobaric hypoxia: implications for passengers' sleep, oxygen saturation and heart rate on long-haul flights. Thorax 2024:thorax-2023-220998. [PMID: 38830667 DOI: 10.1136/thorax-2023-220998] [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: 09/21/2023] [Accepted: 02/09/2024] [Indexed: 06/05/2024]
Abstract
BACKGROUND Passengers on long-haul flights frequently consume alcohol. Inflight sleep exacerbates the fall in blood oxygen saturation (SpO2) caused by the decreased oxygen partial pressure in the cabin. We investigated the combined influence of alcohol and hypobaric hypoxia on sleep, SpO2 and heart rate. METHODS Two groups of healthy individuals spent either two nights with a 4-hour sleep opportunity (00:00-04:00 hours) in the sleep laboratory (n=23; 53 m above sea level) or in the altitude chamber (n=17; 753 hPa corresponding to 2438 m above sea level, hypobaric condition). Participants consumed alcohol before one of the nights (mean±SE blood alcohol concentration 0.043±0.003%). The order of the nights was counterbalanced. Two 8-hour recovery nights (23:00-07:00 hours) were scheduled between conditions. Polysomnography, SpO2 and heart rate were recorded. RESULTS The combined exposure to alcohol and hypobaric condition decreased SpO2 to a median (25th/75th percentile) of 85.32% (82.86/85.93) and increased heart rate to a median (25th/75th percentile) of 87.73 bpm (85.89/93.86) during sleep compared with 88.07% (86.50/88.49) and 72.90 bpm (70.90/78.17), respectively, in the non-alcohol hypobaric condition, 94.97% (94.59/95.33) and 76.97 bpm (65.17/79.52), respectively, in the alcohol condition and 95.88% (95.72/96.36) and 63.74 bpm (55.55/70.98), respectively, in the non-alcohol condition of the sleep laboratory group (all p<0.0001). Under the combined exposure SpO2 was 201.18 min (188.08/214.42) below the clinical hypoxia threshold of 90% SpO2 compared with 173.28 min (133.25/199.03) in the hypobaric condition and 0 min (0/0) in both sleep laboratory conditions. Deep sleep (N3) was reduced to 46.50 min (39.00/57.00) under the combined exposure compared with both sleep laboratory conditions (alcohol: 84.00 min (62.25/92.75); non-alcohol: 67.50 min (58.50/87.75); both p<0.003). CONCLUSIONS The combination of alcohol and inflight hypobaric hypoxia reduced sleep quality, challenged the cardiovascular system and led to extended duration of hypoxaemia (SpO2 <90%).
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Affiliation(s)
- Rabea Antonia Trammer
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Daniel Rooney
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Sibylle Benderoth
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Martin Wittkowski
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Juergen Wenzel
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Eva-Maria Elmenhorst
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
- Institute of Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Self AA, Mesarwi OA. Intermittent Versus Sustained Hypoxemia from Sleep-disordered Breathing: Outcomes in Patients with Chronic Lung Disease and High Altitude. Sleep Med Clin 2024; 19:327-337. [PMID: 38692756 DOI: 10.1016/j.jsmc.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
In a variety of physiologic and pathologic states, people may experience both chronic sustained hypoxemia and intermittent hypoxemia ("combined" or "overlap" hypoxemia). In general, hypoxemia in such instances predicts a variety of maladaptive outcomes, including excess cardiovascular disease or mortality. However, hypoxemia may be one of the myriad phenotypic effects in such states, making it difficult to ascertain whether adverse outcomes are primarily driven by hypoxemia, and if so, whether these effects are due to intermittent versus sustained hypoxemia.
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Affiliation(s)
- Alyssa A Self
- Division of Pulmonary, Critical Care, and Sleep Medicine and Physiology, University of California, San Diego, 9500 Gilman Drive Mail Code 0623A, La Jolla, CA 92093, USA
| | - Omar A Mesarwi
- Division of Pulmonary, Critical Care, and Sleep Medicine and Physiology, University of California, San Diego, 9500 Gilman Drive Mail Code 0623A, La Jolla, CA 92093, USA.
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Mateikaitė-Pipirienė K, Jean D, Paal P, Horakova L, Kriemler S, Rosier AJ, Andjelkovic M, Beidleman BA, Derstine M, Hefti JP, Hillebrandt D, Keyes LE. Menopause and High Altitude: A Scoping Review-UIAA Medical Commission Recommendations. High Alt Med Biol 2024; 25:1-8. [PMID: 37922458 DOI: 10.1089/ham.2023.0039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2023] Open
Abstract
Mateikaitė-Pipirienė, Kastė, Dominique Jean, Peter Paal, Lenka Horakova, Susi Kriemler, Alison J. Rosier, Marija Andjelkovic, Beth A. Beidleman, Mia Derstine, Jacqueline Pichler Hefti, David Hillebrandt, and Linda E. Keyes for the UIAA MedCom writing group on Women's Health in the Mountains. Menopause and high altitude: A scoping review-UIAA Medical Commission Recommendations. High Alt Med Biol. 25:1-8, 2024. Background: Older people are an important fraction of mountain travelers and climbers, many of them postmenopausal women. The aim of this work was to review health issues that older and postmenopausal women may experience at high altitude, including susceptibility to high-altitude illness. Methods: We performed a scoping review for the UIAA Medical Commission series on Women's Health in the mountains. We searched PubMed and Cochrane libraries and performed an additional manual search. The primary search focused on articles assessing lowland women sojourning at high altitude. Results: We screened 7,165 potential articles. The search revealed three relevant articles, and the manual search another seven articles and one abstract. Seven assessed menopausal low-altitude residents during a high-altitude sojourn or performing hypoxic tests. Four assessed high-altitude residents. We summarize the results of these 11 studies. Conclusions: Data are limited on the effects of high altitude on postmenopausal women. The effects of short-term, high-altitude exposure on menopause symptoms are unknown. Menopause has minimal effect on the physiological responses to hypoxia in physically fit women and does not increase the risk of acute mountain sickness. Postmenopausal women have an increased risk of urinary tract infections, which may be exacerbated during mountain travel. More research is needed on the physiology and performance of older women at high altitude.
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Affiliation(s)
- Kastė Mateikaitė-Pipirienė
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Diaverum Clinics, Elektrėnai Division, Lithuania
| | - Dominique Jean
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Paediatrics, Infectious Diseases and Altitude Medicine, Grenoble, France
| | - Peter Paal
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Department of Anaesthesiology and Intensive Care Medicine, St. John of God Hospital, Paracelesus Medical University, Salzburg, Austria
| | - Lenka Horakova
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Susi Kriemler
- Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland
| | - Alison J Rosier
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
| | - Marija Andjelkovic
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Pharmacy, Singidunum University, Belgrade, Serbia
| | - Beth A Beidleman
- US Army Research Institute of Environmental Medicine, Military Performance Division, Natick MA
| | - Mia Derstine
- Department of Emergency Medicine, University of Colorado, Aurora, Colorado, USA
| | | | - David Hillebrandt
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- General Medical Practitioner, Holsworthy, Devon, United Kingdom
| | - Linda E Keyes
- Department of Emergency Medicine, University of Colorado, Aurora, Colorado, USA
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Ibrahim A, Stefani A, Cesari M, Roche J, Gatterer H, Holzknecht E, Turner R, Vinetti G, Furian M, Heidbreder A, Högl B, Siebenmann C. Effects of periodic breathing on sleep at high altitude: a randomized, placebo-controlled, crossover study using inspiratory CO 2. J Physiol 2024. [PMID: 38408065 DOI: 10.1113/jp285397] [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: 08/23/2023] [Accepted: 01/17/2024] [Indexed: 02/28/2024] Open
Abstract
Hypoxia at high altitude facilitates changes in ventilatory control that can lead to nocturnal periodic breathing (nPB). Here, we introduce a placebo-controlled approach to prevent nPB by increasing inspiratory CO2 and used it to assess whether nPB contributes to the adverse effects of hypoxia on sleep architecture. In a randomized, single-blinded, crossover design, 12 men underwent two sojourns (three days/nights each, separated by 4 weeks) in hypobaric hypoxia corresponding to 4000 m altitude, with polysomnography during the first and third night of each sojourn. During all nights, subjects' heads were encompassed by a canopy retaining exhaled CO2 , and CO2 concentration in the canopy (i.e. inspiratory CO2 concentration) was controlled by adjustment of fresh air inflow. Throughout the placebo sojourn inspiratory CO2 was ≤0.2%, whereas throughout the other sojourn it was increased to 1.76% (IQR, 1.07%-2.44%). During the placebo sojourn, total sleep time (TST) with nPB was 54.3% (37.4%-80.8%) and 45.0% (24.5%-56.5%) during the first and the third night, respectively (P = 0.042). Increased inspiratory CO2 reduced TST with nPB by an absolute 38.1% (28.1%-48.1%), the apnoea-hypopnoea index by 58.1/h (40.1-76.1/h), and oxygen desaturation index ≥3% by 56.0/h (38.9.1-73.2/h) (all P < 0.001), whereas it increased the mean arterial oxygen saturation in TST by 2.0% (0.4%-3.5%, P = 0.035). Increased inspiratory CO2 slightly increased the percentage of N3 sleep during the third night (P = 0.045), without other effects on sleep architecture. Increasing inspiratory CO2 effectively prevented hypoxia-induced nPB without affecting sleep macro-architecture, indicating that nPB does not explain the sleep deterioration commonly observed at high altitudes. KEY POINTS: Periodic breathing is common during sleep at high altitude, and it is unclear how this affects sleep architecture. We developed a placebo-controlled approach to prevent nocturnal periodic breathing (nPB) with inspiratory CO2 administration and used it to assess the effects of nPB on sleep in hypobaric hypoxia. Nocturnal periodic breathing was effectively mitigated by an increased inspiratory CO2 fraction in a blinded manner. Prevention of nPB did not lead to relevant changes in sleep architecture in hypobaric hypoxia. We conclude that nPB does not explain the deterioration in sleep architecture commonly observed at high altitude.
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Affiliation(s)
- Abubaker Ibrahim
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Ambra Stefani
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Matteo Cesari
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Johanna Roche
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Hannes Gatterer
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Evi Holzknecht
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Rachel Turner
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Giovanni Vinetti
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Anna Heidbreder
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Birgit Högl
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
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Kanaoka T, Tran K, Lee W. Discrepant home sleep apnea tests and discrepant CPAP downloads: a tale of two altitudes. J Clin Sleep Med 2024; 20:323-325. [PMID: 37889161 PMCID: PMC10835770 DOI: 10.5664/jcsm.10894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 10/26/2023] [Accepted: 10/26/2023] [Indexed: 10/28/2023]
Affiliation(s)
| | - Katie Tran
- University of Texas Southwestern, Dallas, Texas
| | - Won Lee
- University of Texas Southwestern, Dallas, Texas
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Falla M, Hüfner K, Falk M, Weiss EM, Vögele A, Jan van Veelen M, Weber B, Brandner J, Palma M, Dejaco A, Brugger H, Strapazzon G. Simulated Acute Hypobaric Hypoxia Effects on Cognition in Helicopter Emergency Medical Service Personnel - A Randomized, Controlled, Single-Blind, Crossover Trial. HUMAN FACTORS 2024; 66:404-423. [PMID: 35640630 DOI: 10.1177/00187208221086407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
OBJECTIVE To evaluate, under replicable, blinded and standardised conditions, the effect of acute exposure to hypobaric hypoxia (HH) (equivalent to 200 or 3000 or 5000 m above sea level (asl)) on selected cognitive domains and physiological parameters in personnel of helicopter emergency medical service (HEMS). METHODS We conducted a randomized clinical trial using a single-blind crossover design in an environmental chamber (terraXcube) to induce HH in 48 HEMS personnel. Participants performed cognitive tests (CT) before the ascent, after 5 min at altitude, and after simulated cardiopulmonary resuscitation (SCR). CT evaluated: sustained attention using the psychomotor vigilance test (PVT) that included measurement of reaction time (RT); risky decision making using the balloon analogue risk task (BART), and attention and speed of processing using the digit symbol substitution test (DSST). CT performance was subjectively rated with a visual analogue scale (VAS). Physiological data were recorded with a physiological monitoring system. Data were analysed using a linear mixed model and correlation analysis. RESULTS Mean reaction time was significantly slower (p = 0.002) at HH (5000 m asl), but there were no independent effects of HH on the other parameters of the PVT, BART or DSST. Participants did not detect subjectively the slower RT at altitude since VAS performance results showed a positive correlation with mean RT (p = 0.009). DSST results significantly improved (p = 0.001) after SCR. CONCLUSION Acute exposure of HEMS personnel to HH induced a slower RT but no changes in any other investigated measures of cognition. The reduced RT was not detected subjectively by the participants. Trial number 3489044136, ClinicalTrials.gov trial registration.
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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 (TN), Italy
| | - Katharina Hüfner
- Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry II, Medical University of Innsbruck, Innsbruck, Austria
| | - Markus Falk
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Elisabeth M Weiss
- Department of Psychology, University of Innsbruck, Innsbruck, Austria
| | | | | | - Bernhard Weber
- Department of Psychology, University of Graz, Graz, Austria
| | - Jonas Brandner
- Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry II, Medical University of Innsbruck, Innsbruck, Austria
| | - Martin Palma
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Alexander Dejaco
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Hermann Brugger
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy, International Commission for Alpine Emergency Medicine (ICAR MEDCOM), Kloten, Switzerland
| | - Giacomo Strapazzon
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy, International Commission for Alpine Emergency Medicine (ICAR MEDCOM), Kloten, Switzerland
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Fan H, Meng Y, Zhu L, Fan M, Wang D, Zhao Y. A review of methods for assessment of cognitive function in high-altitude hypoxic environments. Brain Behav 2024; 14:e3418. [PMID: 38409925 PMCID: PMC10897364 DOI: 10.1002/brb3.3418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/03/2024] [Accepted: 01/13/2024] [Indexed: 02/28/2024] Open
Abstract
Hypoxic environments like those present at high altitudes may negatively affect brain function. Varying levels of hypoxia, whether acute or chronic, are previously shown to impair cognitive function in humans. Assessment and prevention of such cognitive impairment require detection of cognitive changes and impairment using specific cognitive function assessment tools. This paper summarizes the findings of previous research, outlines the methods for cognitive function assessment used at a high altitude, elaborates the need to develop standardized and systematic cognitive function assessment tools for high-altitude hypoxia environments.
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Affiliation(s)
- Haojie Fan
- Department of PsychologyZhejiang Sci‐Tech UniversityHangzhouChina
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
| | - Ying Meng
- Department of PsychologyZhejiang Sci‐Tech UniversityHangzhouChina
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
| | - Lingling Zhu
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
| | - Ming Fan
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
- School of Information Sciences & EngineeringLanzhou UniversityLanzhouChina
| | - Du‐Ming Wang
- Department of PsychologyZhejiang Sci‐Tech UniversityHangzhouChina
| | - Yong‐Qi Zhao
- Department of PsychologyZhejiang Sci‐Tech UniversityHangzhouChina
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
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Tan L, Li Y, Chen H, Lanzi G, Hu X. Sleep at high altitude: A bibliometric study and visualization analysis from 1992 to 2022. Heliyon 2024; 10:e23041. [PMID: 38163230 PMCID: PMC10755286 DOI: 10.1016/j.heliyon.2023.e23041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/20/2023] [Accepted: 11/24/2023] [Indexed: 01/03/2024] Open
Abstract
Background As an important monitoring index for adaptation to hypoxia, sleep may reflect the adaptive state of the body at high altitudes. The literature has shown a link between altitude and sleep problems, and sleep changes have become a common problem for individuals at high altitudes, negatively impacting their physical and mental health. As research on high-altitude sleep has gained attention in recent years, the publishing volume has increased worldwide, necessitating a more comprehensive understanding of this field. This manuscript evaluates the key themes and emerging trends in high-altitude sleep over the past few decades and predicts future research directions. Methods Articles related to high-altitude sleep published from 1992 to 2022 were retrieved from the Web of Science Core Collection, and the relevant literature characteristics were extracted after the screening. Then, bibliometric analyses and visualizations were performed using Microsoft Excel, CiteSpace, VOSviewer, and an online analysis platform (http://bibliometric.com). Results A total of 1151 articles were retrieved, of which 368 were included in the analysis, indicating a gradually increasing trend. The United States, Switzerland, and China have made significant contributions in this field. Bloch KE from the University of Zurich was determined to be the most productive and academically influential author in this field. The highest-yielding journal was High Altitude Medicine & Biology. Initially, altitude training was the primary research topic. Currently, research focuses on sleep disorders and sleep apnea. In the coming years, keywords such as "sleep quality," "prevalence," and "obstructive sleep apnea" will attract more attention. Conclusion Our findings will assist scholars to better understand the intellectual structure and emerging trends in this field. Future developments in high-altitude sleep research are highly anticipated, particularly in terms of sleep quality at high altitudes and its associated prevalence. This research is also crucial for the improvement and treatment of symptoms during nocturnal sleep in patients with chronic hypoxia due to cardiopulmonary diseases at high altitudes.
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Affiliation(s)
- Lixia Tan
- Innovation Center of Nursing Research and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
- Medical College, Tibet University, Lhasa, China
| | - Yong Li
- Innovation Center of Nursing Research and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
| | - Hongxiu Chen
- Innovation Center of Nursing Research and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
| | | | - Xiuying Hu
- Innovation Center of Nursing Research and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
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Mutschler T, Furian M, Lichtblau M, Buergin A, Schneider SR, Appenzeller P, Mayer L, Muralt L, Mademilov M, Abdyraeva A, Aidaralieva S, Muratbekova A, Akylbekov A, Shabykeeva S, Sooronbaev TM, Ulrich S, Bloch KE. Effect of altitude and acetazolamide on postural control in healthy lowlanders 40 years of age or older. Randomized, placebo-controlled trial. Front Physiol 2024; 14:1274111. [PMID: 38250659 PMCID: PMC10797772 DOI: 10.3389/fphys.2023.1274111] [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: 08/07/2023] [Accepted: 12/06/2023] [Indexed: 01/23/2024] Open
Abstract
Background: Hypoxia and old age impair postural control and may therefore enhance the risk of accidents. We investigated whether acetazolamide, the recommended drug for prevention of acute mountain sickness, may prevent altitude-induced deterioration of postural control in older persons. Methods: In this parallel-design trial, 95 healthy volunteers, 40 years of age or older, living <1,000 m, were randomized to preventive therapy with acetazolamide (375 mg/d) or placebo starting 24 h before and during a 2-day sojourn at 3,100 m. Instability of postural control was quantified by a balance platform with the center of pressure path length (COPL) as primary outcome while pulse oximetry (SpO2) was monitored. Effects of altitude and treatment on COPL were evaluated by ordered logistic regression. www.ClinicalTrials.gov NCT03536429. Results: In participants taking placebo, ascent from 760 m to 3,100 m increased median COPL from 25.8 cm to 27.6 cm (odds ratio 3.80, 95%CI 2.53-5.70) and decreased SpO2 from 96% to 91% (odds ratio 0.0003, 95%CI 0.0002-0.0007); in participants taking acetazolamide, altitude ascent increased COPL from 24.6 cm to 27.3 cm (odds ratio 2.22, 95%CI 1.57-3.13), while SpO2 decreased from 96% to 93% (odds ratio 0.007, 95%CI 0.004-0.012). Altitude-induced increases in COPL were smaller with acetazolamide vs. placebo (odds ratio 0.58, 95%CI 0.34-0.99) while drops in SpO2 were mitigated (odds ratio 19.2, 95%CI 9.9-37.6). Conclusion: In healthy individuals, 40 years of age or older, postural control was impaired after spending a night at 3,100 m. The altitude-induced deterioration of postural control was mitigated by acetazolamide, most likely due to the associated improvement in oxygenation.
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Affiliation(s)
- Tim Mutschler
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
| | - Aline Buergin
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
| | - Simon R. Schneider
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
| | - Paula Appenzeller
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
| | - Laura Mayer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
| | - Lara Muralt
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
| | - Maamed Mademilov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Ainura Abdyraeva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Shoira Aidaralieva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Aibermet Muratbekova
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Azamat Akylbekov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Saltanat Shabykeeva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Talant M. Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
| | - Konrad E. Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyzstan
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11
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Grimm M, Seglias A, Ziegler L, Mademilov M, Isaeva E, Tynybekov K, Tilebalieva A, Osmonbaeva N, Furian M, Sooronbaev TM, Ulrich S, Bloch KE. Sleep apnea in school-age children living at high altitude. Pulmonology 2023; 29:385-391. [PMID: 36964122 DOI: 10.1016/j.pulmoe.2023.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/01/2023] [Accepted: 02/09/2023] [Indexed: 03/26/2023] Open
Abstract
INTRODUCTION Among adults, sleep apnea is more common in highlanders than in lowlanders. We evaluated the sleep apnea prevalence in children living at high altitude compared to age-matched low-altitude controls. METHODS Healthy children, 7-14 y of age, living at 2500-3800m in the Tien Shan mountains, Kyrgyzstan, were prospectively studied in a health post at 3250m. Healthy controls of similar age living at 700-800m were studied in a University Hospital at 760m in Bishkek. Assessments included respiratory sleep studies scored according to pediatric standards, clinical examination, medical history, and the pediatric sleep questionnaire (PSQ, range 0 to 1 with increasing symptoms). RESULTS In children living at high altitude (n = 37, 17 girls, median [quartiles] age 10.8y [9.6;13.0]), sleep studies revealed: mean nocturnal pulse oximetry 90% (89;91), oxygen desaturation index (ODI, >3% dips in pulse oximetry) 4.3/h (2.5;6.7), apnea/hypopnea index (AHI) total 1.7/h (1.0;3.6), central 1.6/h (1.0;3.3), PSQ 0.27 (0.18;0.45). In low-altitude controls (n=41, 17 girls, age 11.6y [9.5;13.0], between-groups comparison of age P=0.69) sleep studies revealed: pulse oximetry 97% (96;97), ODI 0.7/h (0.2;1.2), AHI total 0.4/h (0.1;1.0), central 0.3/h (0.1;0.7), PSQ 0.18 (0.14;0.31); P<0.05, all corresponding between-group comparisons. CONCLUSIONS In school-age children living at high altitude, nocturnal oxygen saturation was lower, and the total and central AHI were higher compared to children living at low altitude. The greater score of sleep symptoms in children residing at high altitude suggests a potential clinical relevance of the nocturnal hypoxemia and subtle sleep-related breathing disturbances.
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Affiliation(s)
- M Grimm
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - A Seglias
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - L Ziegler
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - M Mademilov
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - E Isaeva
- National Center of Maternity and Childhood Care, Bishkek, Kyrgyz Republic; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - K Tynybekov
- National Center of Maternity and Childhood Care, Bishkek, Kyrgyz Republic; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - A Tilebalieva
- National Center of Maternity and Childhood Care, Bishkek, Kyrgyz Republic; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - N Osmonbaeva
- National Center of Maternity and Childhood Care, Bishkek, Kyrgyz Republic; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - M Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - T M Sooronbaev
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - S Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - K E Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland; Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic.
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12
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Bird JD, Sands SA, Alex RM, Shing CLH, Shafer BM, Jendzjowsky NG, Wilson RJA, Day TA, Foster GE. Sex-related Differences in Loop Gain during High-Altitude Sleep-disordered Breathing. Ann Am Thorac Soc 2023; 20:1192-1200. [PMID: 37000675 PMCID: PMC10405604 DOI: 10.1513/annalsats.202211-918oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 03/31/2023] [Indexed: 04/01/2023] Open
Abstract
Rationale: Central sleep apnea (CSA) is pervasive during sleep at high altitude, disproportionately impacting men and associated with increased peripheral chemosensitivity. Objectives: We aimed to assess whether biological sex affects loop gain (LGn) and CSA severity during sleep over 9-10 days of acclimatization to 3,800 m. We hypothesized that CSA severity would worsen with acclimatization in men but not in women because of greater increases in LGn in men. Methods: Sleep studies were collected from 20 (12 male) healthy participants at low altitude (1,130 m, baseline) and after ascent to (nights 2/3, acute) and residence at high altitude (nights 9/10, prolonged). CSA severity was quantified as the respiratory event index (REI) as a surrogate of the apnea-hypopnea index. LGn, a measure of ventilatory control instability, was quantified using a ventilatory control model fit to nasal flow. Linear mixed models evaluated effects of time at altitude and sex on respiratory event index and LGn. Data are presented as contrast means with 95% confidence intervals. Results: REI was comparable between men and women at acute altitude (4.1 [-9.3, 17.5] events/h; P = 0.54) but significantly greater in men at prolonged altitude (23.7 [10.3, 37.1] events/h; P = 0.0008). Men had greater LGn than did women for acute (0.08 [0.001, 0.15]; P = 0.047) and prolonged (0.17 [0.10, 0.25]; P < 0.0001) altitude. The change in REI per change in LGn was significantly greater in men than in women (107 ± 46 events/h/LGn; P = 0.02). Conclusions: The LGn response to high altitude differed between sexes and contributed to worsening of CSA over time in men but not in women. This sex difference in acclimatization appears to protect females from high altitude-related CSA. These data provide fundamental sex-specific physiological insight into high-altitude acclimatization in healthy individuals and may help to inform sex differences in sleep-disordered breathing pathogenesis in patients with cardiorespiratory disease.
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Affiliation(s)
- Jordan D. Bird
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
- Faculty of Science and Technology, Department of Biology, Mount Royal University, Calgary, Alberta, Canada
| | - Scott A. Sands
- Division of Sleep Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts
| | - Raichel M. Alex
- Division of Sleep Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts
| | - Conan L. H. Shing
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Brooke M. Shafer
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Nicholas G. Jendzjowsky
- Respiratory Medicine and Exercise Physiology, The Lundquist Institute for Biomedical Innovation, Harbor University of California Los Angeles Medical Center, West Carson, California; and
| | - Richard J. A. Wilson
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Trevor A. Day
- Faculty of Science and Technology, Department of Biology, Mount Royal University, Calgary, Alberta, Canada
| | - Glen E. Foster
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
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13
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Forrer A, Gaisl T, Sevik A, Meyer M, Senteler L, Lichtblau M, Bloch KE, Ulrich S, Furian M. Partial Pressure of Arterial Oxygen in Healthy Adults at High Altitudes: A Systematic Review and Meta-Analysis. JAMA Netw Open 2023; 6:e2318036. [PMID: 37326993 PMCID: PMC10276310 DOI: 10.1001/jamanetworkopen.2023.18036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/27/2023] [Indexed: 06/17/2023] Open
Abstract
Importance With increasing altitude, the partial pressure of inspired oxygen decreases and, consequently, the Pao2 decreases. Even though this phenomenon is well known, the extent of the reduction as a function of altitude remains unknown. Objective To calculate an effect size estimate for the decrease in Pao2 with each kilometer of vertical gain among healthy unacclimatized adults and to identify factors associated with Pao2 at high altitude (HA). Data Sources A systematic search of PubMed and Embase was performed from database inception to April 11, 2023. Search terms included arterial blood gases and altitude. Study Selection A total of 53 peer-reviewed prospective studies in healthy adults providing results of arterial blood gas analysis at low altitude (<1500 m) and within the first 3 days at the target altitude (≥1500 m) were analyzed. Data Extraction and Synthesis Primary and secondary outcomes as well as study characteristics were extracted from the included studies, and individual participant data (IPD) were requested. Estimates were pooled using a random-effects DerSimonian-Laird model for the meta-analysis. Main Outcomes and Measures Mean effect size estimates and 95% CIs for reduction in Pao2 at HA and factors associated with Pao2 at HA in healthy adults. Results All of the 53 studies involving 777 adults (mean [SD] age, 36.2 [10.5] years; 510 men [65.6%]) reporting 115 group ascents to altitudes between 1524 m and 8730 m were included in the aggregated data analysis; 13 of those studies involving 305 individuals (mean [SD] age, 39.8 [13.6] years; 185 men [60.7%]) reporting 29 ascents were included in the IPD analysis. The estimated effect size of Pao2 was -1.60 kPa (95% CI, -1.73 to -1.47 kPa) for each 1000 m of altitude gain (τ2 = 0.14; I2 = 86%). The Pao2 estimation model based on IPD data revealed that target altitude (-1.53 kPa per 1000 m; 95% CI, -1.63 to -1.42 kPa per 1000 m), age (-0.01 kPa per year; 95% CI, -0.02 to -0.003 kPa per year), and time spent at an altitude of 1500 m or higher (0.16 kPa per day; 95% CI, 0.11-0.21 kPa per day) were significantly associated with Pao2. Conclusions and Relevance In this systematic review and meta-analysis, the mean decrease in Pao2 was 1.60 kPa per 1000 m of vertical ascent. This effect size estimate may improve the understanding of physiological mechanisms, assist in the clinical interpretation of acute altitude illness in healthy individuals, and serve as a reference for physicians counseling patients with cardiorespiratory disease who are traveling to HA regions.
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Affiliation(s)
- Aglaia Forrer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Thomas Gaisl
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Ahmet Sevik
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Michelle Meyer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Luzi Senteler
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Konrad Ernst Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland
- Research Department, Swiss University for Traditional Chinese Medicine, Bad Zurzach, Switzerland
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14
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Rojas-Córdova S, Torres-Fraga MG, Rodríguez-Reyes YG, Guerrero-Zúñiga S, Vázquez-García JC, Carrillo-Alduenda JL. Altitude and Breathing during Sleep in Healthy Persons and Sleep Disordered Patients: A Systematic Review. Sleep Sci 2023; 16:117-126. [PMID: 37151770 PMCID: PMC10157825 DOI: 10.1055/s-0043-1767745] [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: 10/12/2021] [Accepted: 06/28/2022] [Indexed: 05/09/2023] Open
Abstract
Objetive The aim of this systematic review is to analyze the recent scientific evidence of the clinical effects of altitude on breathing during sleep in healthy persons and sleep disordered patients. Material and Methods A search was carried out in PubMed and Scopus looking for articles published between January 1, 2010 and December 31, 2021, in English and Spanish, with the following search terms: "sleep disorders breathing and altitude". Investigations in adults and carried out at an altitude of 2000 meters above mean sea level (MAMSL) or higher were included. The correlation between altitude, apnea hypopnea index (AHI) and mean SpO2 during sleep was calculated. Results 18 articles of the 112 identified were included. A good correlation was found between altitude and AHI (Rs = 0.66 P = 0.001), at the expense of an increase in the central apnea index. Altitude is inversely proportional to oxygenation during sleep (Rs = -0.93 P = 0.001), and an increase in the desaturation index was observed (3% and 4%). On the treatment of respiratory disorders of sleeping at altitude, oxygen is better than servoventilation to correct oxygenation during sleep in healthy subjects and acetazolamide controlled respiratory events and oxygenation during sleep in patients with obstructive sleep apnea under treatment with CPAP. Conclusions Altitude increases AHI and decreases oxygenation during sleep; oxygen and acetazolamide could be an effective treatment for sleep-disordered breathing at altitude above 2000 MAMSL.
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Affiliation(s)
| | | | | | - Selene Guerrero-Zúñiga
- National Institute of Respiratory Diseases, Sleep Medicine Unit, Mexico City, Mexico City, Mexico
| | | | - José Luis Carrillo-Alduenda
- National Institute of Respiratory Diseases, Sleep Medicine Unit, Mexico City, Mexico City, Mexico
- Address for correspondence José Luis Carrillo-Alduenda
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15
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谭 璐, 唐 向. [Sleep-Disordered Breathing at High Altitude: Its Characteristics and Research Progress in Treatment]. SICHUAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF SICHUAN UNIVERSITY. MEDICAL SCIENCE EDITION 2023; 54:246-251. [PMID: 36949680 PMCID: PMC10409183 DOI: 10.12182/20230360506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Indexed: 03/24/2023]
Abstract
Hypobaric hypoxia in regions of high altitude may increase the risk of having sleep-disordered breathing (SDB). SDB at high altitude mainly refers to the SDB incurred in highlanders and lowlanders at a high altitude. At present, research on SDB at high altitude is mainly focused on these two groups of people. On the one hand, highlanders have SDB at a higher prevalence and greater severity than lowlanders do and highlanders have a prolonged duration of apnea when they travel to low-altitude regions. On the other hand, the severity of SDB increased in lowlanders when they travel to high altitude, represented mainly by an increase in central and hypopnea events. In terms of treatment, a substantial number of studies have shown that medication, including acetazolamide and dexamethasone, and nocturnal oxygen supplementation could improve SDB in lowlanders when they travel to high altitude. However, not much research has been done on the treatment of SDB in highlanders and it has only been reported that nocturnal oxygen supplementation was an available treatment option. Herein, we summarized the latest research findings on SDB at high altitude, providing the basis for further studies about the characteristics and treatments for highlanders with SDB.
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Affiliation(s)
- 璐 谭
- 四川大学华西医院 睡眠医学中心 (成都 610041)Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - 向东 唐
- 四川大学华西医院 睡眠医学中心 (成都 610041)Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu 610041, China
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16
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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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17
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Furian M, Bitos K, Hartmann SE, Muralt L, Lichtblau M, Bader PR, Rawling JM, Ulrich S, Poulin MJ, Bloch KE. Acute high altitude exposure, acclimatization and re-exposure on nocturnal breathing. Front Physiol 2022; 13:965021. [PMID: 36134332 PMCID: PMC9483161 DOI: 10.3389/fphys.2022.965021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/11/2022] [Indexed: 12/02/2022] Open
Abstract
Background: Effects of prolonged and repeated high-altitude exposure on oxygenation and control of breathing remain uncertain. We hypothesized that prolonged and repeated high-altitude exposure will improve altitude-induced deoxygenation and breathing instability. Methods: 21 healthy lowlanders, aged 18-30y, underwent two 7-day sojourns at a high-altitude station in Chile (4–8 hrs/day at 5,050 m, nights at 2,900 m), separated by a 1-week recovery period at 520 m. Respiratory sleep studies recording mean nocturnal pulse oximetry (SpO2), oxygen desaturation index (ODI, >3% dips in SpO2), breathing patterns and subjective sleep quality by visual analog scale (SQ-VAS, 0–100% with increasing quality), were evaluated at 520 m and during nights 1 and 6 at 2,900 m in the 1st and 2nd altitude sojourn. Results: At 520 m, mean ± SD nocturnal SpO2 was 94 ± 1%, ODI 2.2 ± 1.2/h, SQ-VAS 59 ± 20%. Corresponding values at 2,900 m, 1st sojourn, night 1 were: SpO2 86 ± 2%, ODI 23.4 ± 22.8/h, SQ-VAS 39 ± 23%; 1st sojourn, night 6: SpO2 90 ± 1%, ODI 7.3 ± 4.4/h, SQ-VAS 55 ± 20% (p < 0.05, all differences within corresponding variables). Mean differences (Δ, 95%CI) in acute effects (2,900 m, night 1, vs 520 m) between 2nd vs 1st altitude sojourn were: ΔSpO2 0% (-1 to 1), ΔODI -9.2/h (-18.0 to -0.5), ΔSQ-VAS 10% (-6 to 27); differences in acclimatization (changes night 6 vs 1), between 2nd vs 1st sojourn at 2,900 m were: ΔSpO2 -1% (-2 to 0), ΔODI 11.1/h (2.5 to 19.7), ΔSQ-VAS -15% (-31 to 1). Conclusion: Acute high-altitude exposure induced nocturnal hypoxemia, cyclic deoxygenations and impaired sleep quality. Acclimatization mitigated these effects. After recovery at 520 m, repeated exposure diminished high-altitude-induced deoxygenation and breathing instability, suggesting some retention of adaptation induced by the first altitude sojourn while subjective sleep quality remained similarly impaired.
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Affiliation(s)
- Michael Furian
- University Hospital Zurich, Department of Respiratory Medicine, Zurich, Switzerland
| | - Konstantinos Bitos
- University Hospital Zurich, Department of Respiratory Medicine, Zurich, Switzerland
| | - Sara E. Hartmann
- University of Calgary, Cumming School of Medicine, Department of Physiology and Pharmacology and Hotchkiss Brain Institute, Calgary, AB, Canada
| | - Lara Muralt
- University Hospital Zurich, Department of Respiratory Medicine, Zurich, Switzerland
| | - Mona Lichtblau
- University Hospital Zurich, Department of Respiratory Medicine, Zurich, Switzerland
| | - Patrick R. Bader
- University Hospital Zurich, Department of Respiratory Medicine, Zurich, Switzerland
| | - Jean M. Rawling
- University of Calgary, Cumming School of Medicine, Department of Family Medicine, Calgary, AB, Canada
| | - Silvia Ulrich
- University Hospital Zurich, Department of Respiratory Medicine, Zurich, Switzerland
| | - Marc J. Poulin
- University of Calgary, Cumming School of Medicine, Department of Physiology and Pharmacology and Hotchkiss Brain Institute, Calgary, AB, Canada
| | - Konrad E. Bloch
- University Hospital Zurich, Department of Respiratory Medicine, Zurich, Switzerland
- *Correspondence: Konrad E. Bloch,
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Riveros-Rivera A, Penzel T, Gunga HC, Opatz O, Paul F, Klug L, Boschmann M, Mähler A. Hypoxia Differentially Affects Healthy Men and Women During a Daytime Nap With a Dose-Response Relationship: a Randomized, Cross-Over Pilot Study. Front Physiol 2022; 13:899636. [PMID: 35685284 PMCID: PMC9171024 DOI: 10.3389/fphys.2022.899636] [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: 03/18/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022] Open
Abstract
Context: The use of daytime napping as a countermeasure in sleep disturbances has been recommended but its physiological evaluation at high altitude is limited. Objective: To evaluate the neuroendocrine response to hypoxic stress during a daytime nap and its cognitive impact. Design, Subject, and Setting: Randomized, single-blind, three period cross-over pilot study conducted with 15 healthy lowlander subjects (8 women) with a mean (SD) age of 29(6) years (Clinicaltrials identifier: NCT04146857, https://clinicaltrials.gov/ct2/show/NCT04146857?cond=napping&draw=3&rank=12). Interventions: Volunteers underwent a polysomnography, hematological and cognitive evaluation around a 90 min midday nap, being allocated to a randomized sequence of three conditions: normobaric normoxia (NN), normobaric hypoxia at FiO2 14.7% (NH15) and 12.5% (NH13), with a washout period of 1 week between conditions. Results: Primary outcome was the interbeat period measured by the RR interval with electrocardiogram. Compared to normobaric normoxia, RR during napping was shortened by 57 and 206 ms under NH15 and NH13 conditions, respectively (p < 0.001). Sympathetic predominance was evident by heart rate variability analysis and increased epinephrine levels. Concomitantly, there were significant changes in endocrine parameters such as erythropoietin (∼6 UI/L) and cortisol (∼100 nmol/L) (NH13 vs. NN, p < 0.001). Cognitive evaluation revealed changes in the color-word Stroop test. Additionally, although sleep efficiency was preserved, polysomnography showed lesser deep sleep and REM sleep, and periodic breathing, predominantly in men. Conclusion: Although napping in simulated altitude does not appear to significantly affect cognitive performance, sex-dependent changes in cardiac autonomic modulation and respiratory pattern should be considered before napping is prescribed as a countermeasure.
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Affiliation(s)
- Alain Riveros-Rivera
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Physiological Sciences, Faculty of Medicine, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Thomas Penzel
- Interdisciplinary Center of Sleep Medicine, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Hanns-Christian Gunga
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Oliver Opatz
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Friedemann Paul
- Experimental and Clinical Research Center, A Cooperation Between the Max-Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin Berlin, Berlin, Germany
- Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Experimental and Clinical Research Center, Berlin, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Lars Klug
- Experimental and Clinical Research Center, A Cooperation Between the Max-Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin Berlin, Berlin, Germany
- Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Experimental and Clinical Research Center, Berlin, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Michael Boschmann
- Experimental and Clinical Research Center, A Cooperation Between the Max-Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin Berlin, Berlin, Germany
- Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Experimental and Clinical Research Center, Berlin, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Anja Mähler
- Experimental and Clinical Research Center, A Cooperation Between the Max-Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin Berlin, Berlin, Germany
- Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Experimental and Clinical Research Center, Berlin, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
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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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20
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Holthof K, Bridevaux PO, Frésard I. Underlying lung disease and exposure to terrestrial moderate and high altitude: personalised risk assessment. BMC Pulm Med 2022; 22:187. [PMID: 35534855 PMCID: PMC9088024 DOI: 10.1186/s12890-022-01979-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/03/2022] [Indexed: 11/17/2022] Open
Abstract
Once reserved for the fittest, worldwide altitude travel has become increasingly accessible for ageing and less fit people. As a result, more and more individuals with varying degrees of respiratory conditions wish to travel to altitude destinations. Exposure to a hypobaric hypoxic environment at altitude challenges the human body and leads to a series of physiological adaptive mechanisms. These changes, as well as general altitude related risks have been well described in healthy individuals. However, limited data are available on the risks faced by patients with pre-existing lung disease. A comprehensive literature search was conducted. First, we aimed in this review to evaluate health risks of moderate and high terrestrial altitude travel by patients with pre-existing lung disease, including chronic obstructive pulmonary disease, sleep apnoea syndrome, asthma, bullous or cystic lung disease, pulmonary hypertension and interstitial lung disease. Second, we seek to summarise for each underlying lung disease, a personalized pre-travel assessment as well as measures to prevent, monitor and mitigate worsening of underlying respiratory disease during travel.
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Affiliation(s)
- Kirsten Holthof
- Service de pneumologie, Centre Hospitalier du Valais Romand, Avenue du Grand-Champsec 80, 1950, Sion, Switzerland
| | - Pierre-Olivier Bridevaux
- Service de pneumologie, Centre Hospitalier du Valais Romand, Avenue du Grand-Champsec 80, 1950, Sion, Switzerland.,Service de pneumologie, Hôpitaux universitaires de Genève, 1211, Geneva 14, Switzerland.,Geneva Medical School, University of Geneva, Geneva, Switzerland
| | - Isabelle Frésard
- Service de pneumologie, Centre Hospitalier du Valais Romand, Avenue du Grand-Champsec 80, 1950, Sion, Switzerland.
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Elmenhorst EM, Rooney D, Benderoth S, Wittkowski M, Wenzel J, Aeschbach D. Sleep-Induced Hypoxia under Flight Conditions: Implications and Countermeasures for Long-Haul Flight Crews and Passengers. Nat Sci Sleep 2022; 14:193-205. [PMID: 35177944 PMCID: PMC8846622 DOI: 10.2147/nss.s339196] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/22/2021] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Recuperation during sleep on board of commercial long-haul flights is a safety issue of utmost importance for flight crews working extended duty periods. We intended to explore how sleep and blood oxygenation (in wake versus sleep) are affected by the conditions in an airliner at cruising altitude. METHODS Healthy participants' sleep was compared between 4-h sleep opportunities in the sleep laboratory (n = 23; sleep lab, ie, 53 m above sea level) and in an altitude chamber (n = 20; flight level, ie, 753 hPa, corresponding to 2438 m above sea level). A subgroup of 12 participants underwent three additional conditions in the altitude chamber: 1) 4-h sleep at ground level, 2) 4-h sleep at flight level with oxygen partial pressure equivalent to ground level, 3) 4-h monitored wakefulness at flight level. Sleep structure and blood oxygenation were analysed with mixed ANOVAs. RESULTS Total sleep time at flight level compared to in the sleep laboratory was shorter (Δ mean ± standard error -11.1 ± 4.2 min) and included less N3 sleep (Δ -17.6 ± 5.4 min), while blood oxygenation was decreased. Participants spent 69.7% (± 8.3%) of the sleep period time but only 13.2% (± 3.0%) of monitored wakefulness in a hypoxic state (<90% oxygen saturation). Oxygen enrichment of the chamber prevented oxygen desaturation. CONCLUSION Sleep - but not wakefulness - under flight conditions induces hypobaric hypoxia which may contribute to impaired sleep. The results caution against the assumption of equivalent crew recovery in-flight and on the ground but hold promise for oxygen enrichment as a countermeasure. The present results have implications for flight safety and possible long-term consequences for health in crews.
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Affiliation(s)
- Eva-Maria Elmenhorst
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, 51170, Germany
- Institute for Occupational and Social Medicine, Medical Faculty, RWTH Aachen University, Aachen, 52074, Germany
| | - Daniel Rooney
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, 51170, Germany
| | - Sibylle Benderoth
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, 51170, Germany
| | - Martin Wittkowski
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, 51170, Germany
| | - Juergen Wenzel
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, 51170, Germany
| | - Daniel Aeschbach
- Department of Sleep and Human Factors Research, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, 51170, Germany
- Institute of Experimental Epileptology and Cognition Research, University of Bonn Medical Center, Bonn, 53127, Germany
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, 02115, USA
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22
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Figueiredo PS, Sils IV, Staab JE, Fulco CS, Muza SR, Beidleman BA. Acute mountain sickness and sleep disturbances differentially influence cognition and mood during rapid ascent to 3000 and 4050 m. Physiol Rep 2022; 10:e15175. [PMID: 35133088 PMCID: PMC8822873 DOI: 10.14814/phy2.15175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 12/04/2022] Open
Abstract
The impact of acute mountain sickness (AMS) and sleep disturbances on mood and cognition at two altitudes relevant to the working and tourist population is unknown. Twenty unacclimatized lowlanders were exposed to either 3000 m (n = 10; 526 mmHg) or 4050 m (n = 10; 460 mmHg) for 20 h in a hypobaric chamber. AMS prevalence and severity was assessed using the Environmental Symptoms Questionnaire (ESQ) and an AMS‐C score ≥ 0.7 indicated sickness. While sleeping for one night both at sea level (SL) and high altitude (HA), a wrist motion detector was used to measure awakenings (Awak, events/h) and sleep efficiency (Eff, %). If Eff was ≥85%, individuals were considered a good sleeper (Sleep+). Mood and cognition were assessed using the Automated Neuropsychological Assessment Metric and Mood Scale (ANAM‐MS). The ESQ and ANAM‐MS were administered in the morning both at SL and after 20 h at HA. AMS severity (mean ± SE; 1.82 ± 0.27 vs. 0.20 ± 0.27), AMS prevalence (90% vs. 10%), depression (0.63 ± 0.23 vs. 0.00 ± 0.24) Awak (15.6 ± 1.6 vs. 10.1 ± 1.6 events/h), and DeSHr (38.5 ± 6.3 vs. 13.3 ± 6.3 events/h) were greater (p < 0.05) and Eff was lower (69.9 ± 5.3% vs. 87.0 ± 5.3%) at 4050 m compared to 3000 m, respectively. AMS presence did not impact cognition but fatigue (2.17 ± 0.37 vs. 0.58 ± 0.39), anger (0.65 ± 0.25 vs. 0.02 ± 0.26), depression (0.63 ± 0.23 vs. 0.00 ± 0.24) and sleepiness (4.8 ± 0.4 vs. 2.7 ± 0.5) were greater (p < 0.05) in the AMS+ group. The Sleep− group, compared to the Sleep+ group, had lower (p < 0.05) working memory scores (50 ± 7 vs. 78 ± 9) assessed by the Sternberg 6‐letter memory task, and lower reaction time fatigue scores (157 ± 17 vs. 221 ± 22), assessed by the repeated reaction time test. Overall, AMS, depression, DeSHr, and Awak were increased (p < 0.05) at 4050 m compared to 3000 m. In addition, AMS presence impacted mood while poor sleep impacted cognition which may deteriorate teamwork and/or increase errors in judgement at HA.
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Affiliation(s)
- Peter S. Figueiredo
- Biophysics and Biomedical Modeling Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Ingrid V. Sils
- Thermal and Mountain Medicine Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Janet E. Staab
- Military Performance Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Charles S. Fulco
- Thermal and Mountain Medicine Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Stephen R. Muza
- Strategic Science and Development Office U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
| | - Beth A. Beidleman
- Biophysics and Biomedical Modeling Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts USA
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23
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Smith CM, Salmon OF, Jenkins JR. Effect of moderate and Severe Hypoxic exposure coupled with fatigue on psychomotor vigilance testing, muscle tissue oxygenation, and muscular performance. Curr Res Physiol 2021; 4:243-251. [PMID: 34806034 PMCID: PMC8581267 DOI: 10.1016/j.crphys.2021.11.001] [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: 09/17/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 01/10/2023] Open
Abstract
PURPOSE The purpose of this study is to examine the effects of fatigue on muscular performance, oxygenation saturation, and cognition following acute hypoxic exposure at Normoxia, Moderate Hypoxia (MH), and Severe Hypoxia (SH). METHODS Twelve males performed 3 sets of leg extensions to failure under Normoxia (FiO2: 21%), MH (Fi02: 15.4%), and SH (Fi02: 12.9%). Heart rate, peripheral oxygenation saturation, total saturation index, psychomotor vigilance testing reaction time, psychomotor vigilance error rate, maximum strength, and repetitions to failure were measured throughout each visit. RESULTS The primary findings indicated that MH and SH resulted in significant decreases in psychomotor vigilance test performance (MH: 388.25-427.17 ms, 0.41-0.33 error rate; SH: 398.17-445.42 ms reaction time, 0.25-1.00 error rate), absolute muscle tissue oxygen saturation (Abs-StO2) (MH:67.22% compared to SH:57.56%), but similar muscular strength, heart rate, and patterns of muscle tissue oxygen saturation responses (StO2%) during fatigue when compared to Normoxia. There was an acute decrease in the ability to remain vigilant and/or respond correctly to visual stimuli as indicated by the worsened reaction time (PVTRT) during MH (FiO2: 15.4%) and increased PVTRT and error rate (PVTE) during SH (FiO2: 12.9%) conditions. CONCLUSIONS Acute hypoxic exposure in the current study was not a sufficient stimuli to elicit hypoxic-related changes in HR, muscular strength (1-RM), or repetitions to failure. The SpO2 responses were hypoxic-level dependent with increasing levels of hypoxia resulting in greater and more sustained reductions in SpO2. The combined SpO2 and StO2 responses at MH and SH suggested a balance between the muscles metabolic demand remaining lower than the muscle oxygen diffusion capacity. During the SH condition, Abs-StO2 suggested greater metabolic stress than Normoxia and MH conditions during the fatiguing leg extensions. The patterns of responses for StO2% during the three sets of leg press to failure indicated that exercise is a more potent influencer to muscle oxygenation status than hypoxic conditions (FiO2: 15.4 and 12.9%).
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Affiliation(s)
- Cory M. Smith
- Human & Environmental Physiology Laboratory, The University of Texas at El Paso, El Paso, TX, USA
| | - Owen F. Salmon
- Human & Environmental Physiology Laboratory, The University of Texas at El Paso, El Paso, TX, USA
| | - Jasmin R. Jenkins
- Interdisciplinary Health Sciences PhD Program, The University of Texas at El Paso, El Paso, TX, USA
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24
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Staab JE, Muza SR, Fulco CS, Andrew SP, Beidleman BA. Impact of 2 days of staging at 2500-4300 m on sleep quality and quantity following subsequent exposure to 4300 m. Physiol Rep 2021; 9:e15063. [PMID: 34713967 PMCID: PMC8554773 DOI: 10.14814/phy2.15063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/10/2021] [Accepted: 09/12/2021] [Indexed: 12/21/2022] Open
Abstract
The impact of 2 days of staging at 2500-4300 m on sleep quality and quantity following subsequent exposure to 4300 m was determined. Forty-eight unacclimatized men and women were randomly assigned to stage for 2 days at one of four altitudes (2500, 3000, 3500, or 4300 m) prior to assessment on the summit of Pikes Peak (4300 m) for 2 days. Volunteers slept for one night at sea level (SL), two nights at respective staging altitudes, and two nights at Pikes Peak. Each wore a pulse oximeter to measure sleep arterial oxygen saturation (sSpO2 , %) and number of desaturations (DeSHr, events/hr) and a wrist motion detector to estimate sleep awakenings (Awak, awakes/hr) and sleep efficiency (Eff, %). Acute mountain sickness (AMS) was assessed using the Environmental Symptoms Questionnaire and daytime SpO2 was assessed after AMS measurements. The mean of all variables for both staging days (STG) and Pikes Peak days (PP) was calculated. The sSpO2 and daytime SpO2 decreased (p < 0.05) from SL during STG in all groups in a dose-dependent manner. During STG, DeSHr were higher (p < 0.05), Eff was lower (p < 0.05), and AMS symptoms were higher (p < 0.05) in the 3500 and 4300 m groups compared to the 2500 and 3000 m groups while Awak did not differ (p > 0.05) between groups. At PP, the sSpO2 , DeSHr, Awak, and Eff were similar among all groups but the 2500 m group had greater AMS symptoms (p < 0.05) than the other groups. Two days of staging at 2500-4300 m induced a similar degree of sleep acclimatization during subsequent ascent to 4300 m but the 2500 m group was not protected against AMS at 4300 m.
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Affiliation(s)
- Janet E. Staab
- Military Performance DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Stephen R. Muza
- Strategic Scientific Management OfficeU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Charles S. Fulco
- Thermal and Mountain Medicine DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Sean P. Andrew
- Thermal and Mountain Medicine DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Beth A. Beidleman
- Biophysics and Biomedical Modeling DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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25
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Effects of Altitude on Chronic Obstructive Pulmonary Disease Patients: Risks and Care. Life (Basel) 2021; 11:life11080798. [PMID: 34440542 PMCID: PMC8401125 DOI: 10.3390/life11080798] [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: 07/09/2021] [Revised: 07/28/2021] [Accepted: 08/05/2021] [Indexed: 02/02/2023] Open
Abstract
Air travel and altitude stays have become increasingly frequent within the overall population but also in patients suffering from chronic obstructive pulmonary disease (COPD), which is the most common respiratory disease worldwide. While altitude is well tolerated by most individuals, COPD patients are exposed to some serious complications, that could be life-threatening. COPD patients present not only a respiratory illness but also frequent comorbidities. Beyond oxygen desaturation, it also affects respiratory mechanics, and those patients are at high risk to decompensate a cardiac condition, pulmonary hypertension, or a sleep disorder. Recently, there has been considerable progress in the management of this disease. Nocturnal oxygen therapy, inhaled medications, corticosteroids, inspiratory muscle training, and pulmonary rehabilitation are practical tools that must be developed in the comprehensive care of those patients so as to enable them to afford altitude stays.
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Frost S, E Orr J, Oeung B, Puvvula N, Pham K, Brena R, DeYoung P, Jain S, Sun S, Malhotra A, Heinrich EC. Improvements in sleep-disordered breathing during acclimatization to 3800 m and the impact on cognitive function. Physiol Rep 2021; 9:e14827. [PMID: 33991443 PMCID: PMC8123551 DOI: 10.14814/phy2.14827] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/10/2021] [Indexed: 11/25/2022] Open
Abstract
Sojourners to high altitude often experience poor sleep quality due to sleep‐disordered breathing. Additionally, multiple aspects of cognitive function are impaired at high altitude. However, the impact of acclimatization on sleep‐disordered breathing and whether poor sleep is a major contributor to cognitive impairments at high altitude remains uncertain. We conducted nocturnal actigraphy and polygraphy, as well as daytime cognitive function tests, in 15 participants (33% women) at sea level and over 3 days of partial acclimatization to high altitude (3800 m). Our goal was to determine if sleep‐disordered breathing improved over time and if sleep‐disordered breathing was associated with cognitive function. The apnea–hypopnea index and oxygen desaturation index increased on night 1 (adj. p = 0.026 and adj. p = 0.026, respectively), but both improved over the subsequent 2 nights. These measures were matched by poorer self‐reported sleep quality on the Stanford Sleepiness Scale and PROMIS questionnaires following 1 night at high altitude (adj. p = 0.027 and adj. p = 0.022, respectively). The reaction time on the psychomotor vigilance task was slower at high altitude and did not improve (SL: 199 ± 27, ALT1: 224 ± 33, ALT2: 216 ± 41, ALT3: 212 ± 27 ms). The reaction times on the balloon analog risk task decreased at high altitude (SL: 474 ± 235, ALT1: 375 ± 159, ALT2: 291 ± 102, ALT3: 267 ± 90 ms), perhaps indicating increased risk‐taking behavior. Finally, multiple cognitive function measures were associated with sleep‐disordered breathing and measures of subjective sleep quality, rather than low daytime arterial oxygen saturation. These data indicate that sleep‐disordered breathing at moderately high altitude improves with partial acclimatization and that some aspects of cognitive performance in unacclimatized sojourners may be impacted by poor sleep rather than hypoxemia alone.
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Affiliation(s)
- Shyleen Frost
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Jeremy E Orr
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, School of Medicine, University of California, San Diego, CA, USA
| | - Britney Oeung
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Nikhil Puvvula
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Kathy Pham
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Rebbecca Brena
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, School of Medicine, University of California, San Diego, CA, USA
| | - Pamela DeYoung
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, School of Medicine, University of California, San Diego, CA, USA
| | - Sonia Jain
- Biostatistics Research Center, Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, CA, USA
| | - Shelly Sun
- Biostatistics Research Center, Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, CA, USA
| | - Atul Malhotra
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, School of Medicine, University of California, San Diego, CA, USA
| | - Erica C Heinrich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
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Horiuchi M, Watanabe M, Mitsui S, Uno T. Does change in barometric pressure per given time at high altitude influence symptoms of acute mountain sickness on Mount Fuji? A pilot study. J Physiol Anthropol 2021; 40:6. [PMID: 33962688 PMCID: PMC8105930 DOI: 10.1186/s40101-021-00256-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/07/2021] [Indexed: 11/10/2022] Open
Abstract
Background Acute mountain sickness (AMS) is a common, transient condition characterized primarily by headaches, and it can also be associated with fatigue, dizziness, and nausea with vomiting. The symptoms of AMS are most pronounced after the first night spent at a new altitude. At sea level, changes in barometric pressure per given time have been associated with migraine headaches. We sought to investigate whether changes in barometric pressure, subjective sleep quality index, and other candidates contributed to the risk of developing AMS on Mount Fuji in Japan. Method We surveyed 353 trekkers who stayed overnight at a mountain lodge before summitting Mount Fuji. We collected information regarding sex, age, sleeping altitude at the hut, and perceived sleep quality index including sleep time. AMS was assessed with the Lake Louise Scoring system. Barometric pressure and ambient temperature were collected at the 5th station (2305 m) and at the summit (3776 m). Result The overall prevalence of AMS in our cohort was 41.4% (Lake Louise Score ≥ 3 with headache, n=146). Using logistic regression, three factors were combined to generate a robust model for determining the risk of AMS (with or without AMS). These included (1) Δ barometric pressure during ascent per hour, (2) sleepiness on rising, and (3) sleep refreshment assessed by perceived sleep quality index. Conclusion These results suggest that climbers who stay overnight at the lodge should keep a better physical condition of sleep, and would pay attention to information of barometric pressure condition to decrease their risk of AMS at the summit of Mount Fuji. Our observatory data indicated that an overnight staying in half way up to the summit does not necessarily reduce the AMS risk in both sexes and irrespective of age, at least, until 3776 m elevation. Supplementary Information The online version contains supplementary material available at 10.1186/s40101-021-00256-y.
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Affiliation(s)
- Masahiro Horiuchi
- Division of Human Environmental Science, Mount Fuji Research Institute, Kami-yoshida 5597-1, Fujiyoshida, Yamanahsi, 4030005, Japan.
| | - Misato Watanabe
- Division of Human Environmental Science, Mount Fuji Research Institute, Kami-yoshida 5597-1, Fujiyoshida, Yamanahsi, 4030005, Japan
| | - Satomi Mitsui
- Division of Human Environmental Science, Mount Fuji Research Institute, Kami-yoshida 5597-1, Fujiyoshida, Yamanahsi, 4030005, Japan
| | - Tadashi Uno
- Division of Human Environmental Science, Mount Fuji Research Institute, Kami-yoshida 5597-1, Fujiyoshida, Yamanahsi, 4030005, Japan
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Bisang M, Latshang TD, Aeschbacher SS, Huber F, Flueck D, Lichtblau M, Ulrich S, Hasler ED, Scheiwiller PM, Ulrich S, Bloch KE, Furian M. Nocturnal Heart Rate and Cardiac Repolarization in Lowlanders With Chronic Obstructive Pulmonary Disease at High Altitude: Data From a Randomized, Placebo-Controlled Trial of Nocturnal Oxygen Therapy. Front Med (Lausanne) 2021; 8:557369. [PMID: 33732710 PMCID: PMC7956979 DOI: 10.3389/fmed.2021.557369] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 01/25/2021] [Indexed: 01/05/2023] Open
Abstract
Background: Chronic obstructive pulmonary disease (COPD) is associated with cardiovascular disease. We investigated whether sleeping at altitude increases nocturnal heart rate (HR) and other markers of cardiovascular risk or arrhythmias in lowlanders with COPD and whether this can be prevented by nocturnal oxygen therapy (NOT). Methods: Twenty-four COPD patients, with median age of 66 years and forced expiratory volume in 1 s (FEV1) 55% predicted, living <800 m underwent sleep studies at Zurich (490 m) and during 2 sojourns of 2 days each at St. Moritz (2,048 m) separated by 2-week washout at <800 m. During nights at 2,048 m, patients received either NOT (2,048 m NOT) or ambient air (2,048 m placebo) 3 L/min via nasal cannula according to a randomized, placebo-controlled crossover trial. Sleep studies comprised ECG and pulse oximetry to measure HR, rhythm, HR-adjusted QT interval (QTc), and mean oxygen saturation (SpO2). Results: In the first nights at 490 m, 2,048 m placebo, and 2,048 m NOT, medians (quartiles) of SpO2 were 92% (90; 94), 86% (83; 89), and 97% (95; 98) and of HR were 73 (66; 82), 82 (71; 85), and 78 bpm (67; 74) (P < 0.05 all respective comparisons). QTc increased from 417 ms (404; 439) at 490 m to 426 ms (405; 440) at 2,048 m placebo (P < 0.05) and was 420 ms (405; 440) at 2,048 m NOT (P = NS vs. 2,048 m placebo). The number of extrabeats and complex arrhythmias was similar over all conditions. Conclusions: While staying at 2,048 m, lowlanders with COPD experienced nocturnal hypoxemia in association with an increased HR and prolongation of the QTc interval. NOT significantly improved SpO2 and lowered HR, without changing QTc. Whether oxygen therapy would reduce HR and arrhythmia during longer altitude sojourns remains to be elucidated.
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Affiliation(s)
- Maya Bisang
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Tsogyal D Latshang
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Sayaka S Aeschbacher
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Fabienne Huber
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Deborah Flueck
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Mona Lichtblau
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Stefanie Ulrich
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Elisabeth D Hasler
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Philipp M Scheiwiller
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Konrad E Bloch
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Michael Furian
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
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Siebenmann C, Dempsey JA. Hypoxic Training Is Not Beneficial in Elite Athletes. Med Sci Sports Exerc 2020; 52:519-522. [PMID: 31939915 DOI: 10.1249/mss.0000000000002141] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
| | - Jerome A Dempsey
- Department Population Health Sciences, University of Wisconsin-Madison, Madison, WI
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Lichtblau M, Saxer S, Latshang TD, Aeschbacher SS, Huber F, Scheiwiller PM, Herzig JJ, Schneider SR, Hasler ED, Furian M, Bloch KE, Ulrich S. Altitude Travel in Patients With Pulmonary Hypertension: Randomized Pilot-Trial Evaluating Nocturnal Oxygen Therapy. Front Med (Lausanne) 2020; 7:502. [PMID: 32984379 PMCID: PMC7492536 DOI: 10.3389/fmed.2020.00502] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/21/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction: Stable patients with pulmonary arterial or chronic thromboembolic pulmonary hypertension (PH) wish to undergo altitude sojourns or air travel but fear disease worsening. This pilot study investigates health effects of altitude sojourns and potential benefits of nocturnal oxygen therapy (NOT) in PH patients. Methods: Nine stable PH patients, age 65 (47; 71) years, 5 women, in NYHA class II, on optimized medication, were investigated at 490 m and during two sojourns of 2 days/nights at 2,048 m, once using NOT, once placebo (ambient air), 3 L/min per nasal cannula, according to a randomized crossover design with 2 weeks washout at <800 m. Assessments included safety, nocturnal pulse oximetry (SpO2), 6-min walk distance (6 MWD), and echocardiography. Results: At 2,048 m, two of nine patients required medical intervention, one for exercise-induced syncope, one for excessive nocturnal hypoxemia (SpO2 < 75% for >30 min). Both recovered immediately with oxygen therapy. Two patients suffered from acute mountain sickness. In 6 patients with complete data, nocturnal mean SpO2 and cyclic SpO2 dips reflecting sleep apnea significantly differed from 490 to 2,048 m with placebo, and 2,048 m with NOT (medians, quartiles): SpO2 93 (91; 95)%, 89 (85; 90)%, 97 (95; 97)%; SpO2 dips 10.4/h (3.1; 26.9), 34.0/h (5.3; 81.3), 0.3/h (0.1; 2.3). 6 MWD at 490, 2,048 m without and with NOT was 620 m (563; 720), 583 m (467; 696), and 561 m (501; 688). Echocardiographic indices of heart function and PH were unchanged at 2,048 m with/without NOT vs. 490 m. Conclusions: 7/9 PH patients stayed safely at 2,048 m but revealed hypoxemia, sleep apnea, and reduced 6 MWD. Hemodynamic changes were trivial. NOT improved oxygenation and sleep apnea. The current pilot trial is important for designing further studies on altitude tolerance of PH patients.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Silvia Ulrich
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
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31
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Tan L, Latshang TD, Aeschbacher SS, Huber F, Flueck D, Lichtblau M, Ulrich S, Hasler ED, Scheiwiller PM, Ulrich S, Bloch KE, Furian M. Effect of Nocturnal Oxygen Therapy on Nocturnal Hypoxemia and Sleep Apnea Among Patients With Chronic Obstructive Pulmonary Disease Traveling to 2048 Meters: A Randomized Clinical Trial. JAMA Netw Open 2020; 3:e207940. [PMID: 32568400 PMCID: PMC7309443 DOI: 10.1001/jamanetworkopen.2020.7940] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
IMPORTANCE There are no established measures to prevent nocturnal breathing disturbances and other altitude-related adverse health effects (ARAHEs) among lowlanders with chronic obstructive pulmonary disease (COPD) traveling to high altitude. OBJECTIVE To evaluate whether nocturnal oxygen therapy (NOT) prevents nocturnal hypoxemia and breathing disturbances during the first night of a stay at 2048 m and reduces the incidence of ARAHEs. DESIGN, SETTING, AND PARTICIPANTS This randomized, placebo-controlled crossover trial was performed from January to October 2014 with 32 patients with COPD living below 800 m with forced expiratory volume in the first second of expiration (FEV1) between 30% and 80% predicted, pulse oximetry of at least 92%, not requiring oxygen therapy, and without history of sleep apnea. Evaluations were performed at the University Hospital Zurich (490 m, baseline) and during 2 stays of 2 days and nights each in a Swiss Alpine hotel at 2048 m while NOT or placebo treatment was administered in a randomized order. Between altitude sojourns, patients spent at least 2 weeks below 800 m. Data analysis was performed from January 1, 2015, to December 31, 2018. INTERVENTION During nights at 2048 m, NOT or placebo (room air) was administered at 3 L/min by nasal cannula. MAIN OUTCOMES AND MEASURES Coprimary outcomes were differences between NOT and placebo intervention in altitude-induced change in mean nocturnal oxygen saturation (SpO2) as measured by pulse oximetry and apnea-hypopnea index (AHI) measured by polysomnography during night 1 at 2048 m and analyzed according to the intention-to-treat principle. Further outcomes were the incidence of predefined ARAHE, other variables from polysomnography results and respiratory sleep studies in the 2 nights at 2048 m, clinical findings, and symptoms. RESULTS Of the 32 patients included, 17 (53%) were women, with a mean (SD) age of 65.6 (5.6) years and a mean (SD) FEV1 of 53.1% (13.2%) predicted. At 490 m, mean (SD) SpO2 was 92% (2%) and mean (SD) AHI was 21.6/h (22.2/h). At 2048 m with placebo, mean (SD) SpO2 was 86% (3%) and mean (SD) AHI was 34.9/h (20.7/h) (P < .001 for both comparisons). Compared with placebo, NOT increased SpO2 by a mean of 9 percentage points (95% CI, 8-11 percentage points; P < .001), decreased AHI by 19.7/h (95% CI, 11.4/h-27.9/h; P < .001), and improved subjective sleep quality measured on a visual analog scale by 9 percentage points (95% CI, 0-17 percentage points; P = .04). During visits to 2048 m or within 24 hours after descent, 8 patients (26%) using placebo and 1 (4%) using NOT experienced ARAHEs (P < .001). CONCLUSIONS AND RELEVANCE Lowlanders with COPD experienced hypoxemia, sleep apnea, and impaired well-being when staying at 2048 m. Because NOT significantly mitigated these undesirable effects, patients with moderate to severe COPD may benefit from preventive NOT during high altitude travel. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02150590.
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Affiliation(s)
- Lu Tan
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Tsogyal D. Latshang
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Sayaka S. Aeschbacher
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Fabienne Huber
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Deborah Flueck
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Mona Lichtblau
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Stefanie Ulrich
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Elisabeth D. Hasler
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Philipp M. Scheiwiller
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Konrad E. Bloch
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Michael Furian
- Sleep Disorders Center, Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
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Torlasco C, Bilo G, Giuliano A, Soranna D, Ravaro S, Oliverio G, Faini A, Zambon A, Lombardi C, Parati G. Effects of acute exposure to moderate altitude on blood pressure and sleep breathing patterns. Int J Cardiol 2020; 301:173-179. [DOI: 10.1016/j.ijcard.2019.09.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 08/11/2019] [Accepted: 09/16/2019] [Indexed: 11/16/2022]
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Tan L, Li T, Lei F, Li X, Zhou J, Zhang Y, Ren R, Yang L, Tang X. Longer apnea duration at low altitude in Tibetan and Han highlanders compared with Han lowlanders: A retrospective study. J Sleep Res 2019; 29:e12934. [PMID: 31642144 DOI: 10.1111/jsr.12934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/25/2019] [Accepted: 09/25/2019] [Indexed: 02/05/2023]
Abstract
Prolonged duration of obstructive apnea (OA) has been observed in highlanders after descending to low altitude. It is proposed that due to adaptation to a hypoxic high-altitude environment, Tibetan highlanders (TH) and Han highlanders (HH) would manifest different OA durations at low altitude as compared to Han lowlanders (HL). Data collection on consecutive obstructive sleep apnea patients (167 TH, 210 HH and 233 HL) was performed over a period of 8 years in Chengdu (altitude 500 m). The analyses were performed with non-matched groups and with body mass index and apnea-hypopnea index-matched groups. Significance rankings for mean duration of OA (s) in non-matched groups and matched groups were TH (27.7; 28.6) = HH (25.7; 26.0) > HL (21.7; 21.3), respectively. For the longest OA duration, the significance rankings across three groups with regard to the percentage of patients having a duration longer than 2 min (%) and mean values (s) were TH (26.9; 82) > HH (10.0; 67) > HL (1.3; 50). In terms of nadir and mean oxygen saturation, significant differences were found between TH and HH or HL. In addition, longest and mean OA duration were positively correlated with blood pressure and heart rate, whereas nadir and mean oxygen saturation were negatively correlated with these measures in both non-matched and matched groups, and the correlation was more robust in TH. These findings raise important clinical questions regarding whether such significant prolongation of OA duration and a more severe hypoxic burden among highlanders, especially in TH, may lead to adverse clinical consequences when at low altitude.
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Affiliation(s)
- Lu Tan
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Taomei Li
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Fei Lei
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xiao Li
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Junying Zhou
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ye Zhang
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Rong Ren
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Linghui Yang
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xiangdong Tang
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine,Translational Neuroscience Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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The onset of sleep disturbances and their associations with anxiety after acute high-altitude exposure at 3700 m. Transl Psychiatry 2019; 9:175. [PMID: 31332159 PMCID: PMC6646382 DOI: 10.1038/s41398-019-0510-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 04/30/2019] [Accepted: 05/31/2019] [Indexed: 11/22/2022] Open
Abstract
Sleep disturbances and psychiatric repercussions pose great challenges at high altitude; however, few studies have investigated sleep disturbance and anxiety profiles and their associations after acute exposure in consecutive patients. Thus, we aimed to study the profiles of sleep disturbances in consecutive patients after high-altitude exposure and the association of such disturbances with anxiety. A total of 668 participants were recruited at sea level and 3700 m. The trials were performed at sea level (1 week prior to a 2-h flight to a high-altitude destination) and at 3700 m (24, 72, and 168 h). Sleep disturbances were assessed by self-reported sleep patterns and scores on the Athens Insomnia Scale (AIS). State anxiety was assessed using the Self-Rating Anxiety Scale (SAS). In our study, the incidence of sleep disturbances increased significantly after acute high-altitude exposure (65.3%, 434/668) and then gradually decreased after 72 h (50%, 141/282) and 168 h (44%, 124/282). The sleep assessments AIS [2.0 (4.0) vs. 4.0 (5.0)] and ESS [4.0 (4.0) vs. 5.0 (5.0)] increased significantly (p < 0.05). Also, the SAS increased significantly from 26.25 (3.75) to 28.75 (7.5). The SAS was significantly high in sleep disturbance group [31.25 (7.5) vs. 27.5 (5), p < 0.001] than in the non-sleep- disturbance group. The baseline SAS and AIS scores were significantly higher in participants with sleep disturbances than in those without (p < 0.01). Age, baseline insomnia, sleepiness, fatigue, and higher SAS were predictors of sleep disturbances in univariate regression (all p values < 0.05). However, only an older age (p = 0.045) and a higher baseline SAS (p = 0.018) remained independent predictors of sleep disturbances. Our findings indicated that acute high-altitude exposure triggers the onset of sleep disturbances, which are closely associated with anxiety. Furthermore, baseline state anxiety and age are independent predictors of sleep disturbances at high altitude.
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Kentiba E, George M, Mondal S, Mathi Vanan D. Effects of altitude on chronotype orientations in relation to cardiorespiratory and hematological quantities of college students in Ethiopia. PLoS One 2019; 14:e0219836. [PMID: 31314762 PMCID: PMC6636757 DOI: 10.1371/journal.pone.0219836] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 07/02/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The mechanism by which Ethiopians adapt to altitude is quite unique compared to other Highlanders with respect to increased oxygen saturation of hemoglobin. Although the effects of altitude on cardiorespiratory and hematological quantities on athletics performances are well known, but there is little information about its underlying effect on chronotype orientations. METHODS In this cross-sectional study 60 male college students with mean age 20±1.3 years from high and low altitude regions living in a tropical setting in Ethiopia were included. The participants' chronotype was determined using the self-administered Horne and Ostberg Morningness-Eveningness Questionnaires (MEQ). Measurements and estimations of hematological and cardiorespiratory parameters were performed from 7:00-9:00 AM, East African time zone, in order to minimize any variations that might occur in the course of the day. A multivariate binary logistic regression model was fitted to analyze the underlying chronotype predictors. RESULTS 28 (93.9%) of participants from high altitude were mainly intermediate type (I-type) dominant with (MEQ = 42-58). While, 16 (55.2%) of participants from low altitudes were morning type (M-type) dominant chronotype with (MEQ = 59-69). Our main finding confirmed that altitude is an independent predictor of chronotype orientations of the participants (p<0.015). Thus, the results of the multivariate analysis seem to indicate that, participants from low and high altitudes may be uniquely oriented towards either M-type or I-type chronotype respectively (adjusted odds ratio [AOR] 4.772, 95% CI = 3.748-4618458). However, no significant difference on cardiorespiratory and hematological quantities between I-type and M-type chronotype of students from low altitude living in the same setting was reported (p > 0.05). CONCLUSION Our finding, reported for the first time that, the human chronotype varies according to the altitude, with no underlying effect of cardiorespiratory and hematological quantities.
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Affiliation(s)
- Efrem Kentiba
- Department of Sports Science, Arba Minch College of Teachers’ Education, Arba Minch, Ethiopia
- Department of Sports Science, Mekelle University College of Natural and Computational Sciences, Mekelle, Ethiopia
| | - Mala George
- Department of Biochemistry, School of Medicine, Division of Biomedical Sciences, Mekelle University, Mekelle, Ethiopia
| | - Soumitra Mondal
- Department of Sports Science, Mekelle University College of Natural and Computational Sciences, Mekelle, Ethiopia
| | - D. Mathi Vanan
- Department of Sports Science, Mekelle University College of Natural and Computational Sciences, Mekelle, Ethiopia
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Sleep Disordered Breathing at High Altitude in Adults and Its Interaction with Cardiovascular Homeostasis. CURRENT SLEEP MEDICINE REPORTS 2019. [DOI: 10.1007/s40675-019-00138-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Schwarz EI, Latshang TD, Furian M, Flück D, Segitz S, Müller-Mottet S, Ulrich S, Bloch KE, Kohler M. Blood pressure response to exposure to moderate altitude in patients with COPD. Int J Chron Obstruct Pulmon Dis 2019; 14:659-666. [PMID: 30936690 PMCID: PMC6421900 DOI: 10.2147/copd.s194426] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose Patients with COPD might be particularly susceptible to hypoxia-induced autonomic dysregulation. Decreased baroreflex sensitivity (BRS) and increased blood pressure (BP) variability (BPV) are markers of impaired cardiovascular autonomic regulation and there is evidence for an association between decreased BRS/increased BPV and high cardiovascular risk. The aim of this study was to evaluate the effect of short-term exposure to moderate altitude on BP and measures of cardiovascular autonomic regulation in COPD patients. Materials and methods Continuous morning beat-to-beat BP was noninvasively measured with a Finometer® device for 10 minutes at low altitude (490 m, Zurich, Switzerland) and for 2 days at moderate altitude (2,590 m, Davos Jakobshorn, Switzerland) – the order of altitude exposure was randomized. Outcomes of interest were mean SBP and DBP, BPV expressed as the coefficient of variation (CV), and spontaneous BRS. Changes between low altitude and day 1 and day 2 at moderate altitude were assessed by ANOVA for repeated measurements with Fisher’s exact test analysis. Results Thirty-seven patients with moderate to severe COPD (mean±SD age 64±6 years, FEV1 60%±17%) were included. Morning SBP increased by +10.8 mmHg (95% CI: 4.7–17.0, P=0.001) and morning DBP by +5.0 mmHg (95% CI: 0.8–9.3, P=0.02) in response to altitude exposure. BRS significantly decreased (P=0.03), whereas BPV significantly and progressively increased (P<0.001) upon exposure to altitude. Conclusion Exposure of COPD patients to moderate altitude is associated with a clinically relevant increase in BP, which seems to be related to autonomic dysregulation. Clinical trial registration ClinicalTrials.gov (NCT01875133).
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Affiliation(s)
- Esther I Schwarz
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Tsogyal D Latshang
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Michael Furian
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Deborah Flück
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Sebastian Segitz
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Severine Müller-Mottet
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Silvia Ulrich
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland,
| | - Konrad E Bloch
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland, .,Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland,
| | - Malcolm Kohler
- Department of Pulmonology and Sleep Disorders Centre, University Hospital of Zurich, Zurich, Switzerland, .,Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland,
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Furian M, Lichtblau M, Aeschbacher SS, Estebesova B, Emilov B, Sheraliev U, Marazhapov NH, Mademilov M, Osmonov B, Bisang M, Ulrich S, Latshang TD, Ulrich S, Sooronbaev TM, Bloch KE. Effect of Dexamethasone on Nocturnal Oxygenation in Lowlanders With Chronic Obstructive Pulmonary Disease Traveling to 3100 Meters: A Randomized Clinical Trial. JAMA Netw Open 2019; 2:e190067. [PMID: 30794302 PMCID: PMC6484579 DOI: 10.1001/jamanetworkopen.2019.0067] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
IMPORTANCE During mountain travel, patients with chronic obstructive pulmonary disease (COPD) are at risk of experiencing severe hypoxemia, in particular, during sleep. OBJECTIVE To evaluate whether preventive dexamethasone treatment improves nocturnal oxygenation in lowlanders with COPD at 3100 m. DESIGN, SETTING, AND PARTICIPANTS A randomized, placebo-controlled, double-blind, parallel trial was performed from May 1 to August 31, 2015, in 118 patients with COPD (forced expiratory volume in the first second of expiration [FEV1] >50% predicted, pulse oximetry at 760 m ≥92%) who were living at altitudes below 800 m. The study was conducted at a university hospital (760 m) and high-altitude clinic (3100 m) in Tuja-Ashu, Kyrgyz Republic. Patients underwent baseline evaluation at 760 m, were taken by bus to the clinic at 3100 m, and remained at the clinic for 2 days and nights. Participants were randomized 1:1 to receive either dexamethasone, 4 mg, orally twice daily or placebo starting 24 hours before ascent and while staying at 3100 m. Data analysis was performed from September 1, 2015, to December 31, 2016. INTERVENTIONS Dexamethasone, 4 mg, orally twice daily (dexamethasone total daily dose, 8 mg) or placebo starting 24 hours before ascent and while staying at 3100 m. MAIN OUTCOMES AND MEASURES Difference in altitude-induced change in nocturnal mean oxygen saturation measured by pulse oximetry (Spo2) during night 1 at 3100 m between patients receiving dexamethasone and those receiving placebo was the primary outcome and was analyzed according to the intention-to-treat principle. Other outcomes were apnea/hypopnea index (AHI) (mean number of apneas/hypopneas per hour of time in bed), subjective sleep quality measured by a visual analog scale (range, 0 [extremely bad] to 100 [excellent]), and clinical evaluations. RESULTS Among the 118 patients included, 18 (15.3%) were women; the median (interquartile range [IQR]) age was 58 (52-63) years; and FEV1 was 91% predicted (IQR, 73%-103%). In 58 patients receiving placebo, median nocturnal Spo2 at 760 m was 92% (IQR, 91%-93%) and AHI was 20.5 events/h (IQR, 12.3-48.1); during night 1 at 3100 m, Spo2 was 84% (IQR, 83%-85%) and AHI was 39.4 events/h (IQR, 19.3-66.2) (P < .001 both comparisons vs 760 m). In 60 patients receiving dexamethasone, Spo2 at 760 m was 92% (IQR, 91%-93%) and AHI was 25.9 events/h (IQR, 16.3-37.1); during night 1 at 3100 m, Spo2 was 86% (IQR, 84%-88%) (P < .001 vs 760 m) and AHI was 24.7 events/h (IQR, 13.2-33.7) (P = .99 vs 760 m). Altitude-induced decreases in Spo2 during night 1 were mitigated by dexamethasone vs placebo by a mean of 3% (95% CI, 2%-3%), and increases in AHI were reduced by 18.7 events/h (95% CI, 12.0-25.3). Similar effects were observed during night 2. Subjective sleep quality was improved with dexamethasone during night 2 by 12% (95% CI, 0%-23%). Sixteen (27.6%) patients using dexamethasone had asymptomatic hyperglycemia. CONCLUSIONS AND RELEVANCE In lowlanders in Central Asia with COPD traveling to a high altitude, preventive dexamethasone treatment improved nocturnal oxygen saturation, sleep apnea, and subjective sleep quality. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02450994.
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Affiliation(s)
- Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | | | - Bermet Estebesova
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Berik Emilov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ulan Sheraliev
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Nuriddin H. Marazhapov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Maamed Mademilov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Batyr Osmonov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Maya Bisang
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Stefanie Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Tsogyal D. Latshang
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Talant M. Sooronbaev
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Konrad E. Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
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Latshang TD, Tardent RPM, Furian M, Flueck D, Segitz SD, Mueller-Mottet S, Kohler M, Ulrich S, Bloch KE. Sleep and breathing disturbances in patients with chronic obstructive pulmonary disease traveling to altitude: a randomized trial. Sleep 2018; 42:5229280. [DOI: 10.1093/sleep/zsy203] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Tsogyal D Latshang
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - René P M Tardent
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Michael Furian
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Deborah Flueck
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Sebastian D Segitz
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Séverine Mueller-Mottet
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Malcolm Kohler
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Konrad E Bloch
- Department of Respiratory Medicine, Sleep Disorders Center, University Hospital Zurich, Zurich, Switzerland and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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Fruchart E, Raberin A, Durand F. Effect of Hypoxia on Information Integration Capacities. UNIVERSITAS PSYCHOLOGICA 2018. [DOI: 10.11144/javeriana.upsy17-4.ehii] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The effect of hypoxia on cognitive processes is an undisputed finding but its extent remains difficult to predict in each particular circumstance. The present study examined the impact of hypoxia on information integration capacities in daily life settings. A sample of 14 students was presented with a series of cards depicting an object a) having a given volume and made of a given substance, and asked to infer its mass;or b) having a given mass and density, and asked to infer its volume; or c) having a given volume and mass, and asked to infer its density. There were three levels of hypoxia situations. In a baseline situation, participants were instructed to put a mask connected with an AltiTrainer (equipment that regulates the oxygen partial pressure provided through the mask) and to perform the three judgment tasks in close succession. The two other situations were similar to the baseline situation except that the AltiTrainer was configured to simulate altitude levels either 1100 m or 3100 m higher than the one in the baseline situation. Contrary to our expectations, no difference in performance was found between the three experimental situations. People’s information integration capacities are not affected by hypoxia, even if acclimatization to it has not taken place, and as far as it is not too severe.
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Furian M, Flueck D, Latshang TD, Scheiwiller PM, Segitz SD, Mueller-Mottet S, Murer C, Steiner A, Ulrich S, Rothe T, Kohler M, Bloch KE. Exercise performance and symptoms in lowlanders with COPD ascending to moderate altitude: randomized trial. Int J Chron Obstruct Pulmon Dis 2018; 13:3529-3538. [PMID: 30464436 PMCID: PMC6208550 DOI: 10.2147/copd.s173039] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Objective To evaluate the effects of altitude travel on exercise performance and symptoms in lowlanders with COPD. Design Randomized crossover trial. Setting University Hospital Zurich (490 m), research facility in mountain villages, Davos Clavadel (1,650 m) and Davos Jakobshorn (2,590 m). Participants Forty COPD patients, Global Initiative for Obstructive Lung Disease (GOLD) grade 2–3, living below 800 m, median (quartiles) age 67 y (60; 69), forced expiratory volume in 1 second 57% predicted (49; 70). Intervention Two-day sojourns at 490 m, 1,650 m, and 2,590 m in randomized order. Outcome measures Six-minute walk distance (6MWD), cardiopulmonary exercise tests, symptoms, and other health effects. Results At 490 m, days 1 and 2, median (quartiles) 6MWD were 558 m (477; 587) and 577 m (531; 629). At 2,590 m, days 1 and 2, mean changes in 6MWD from corresponding day at 490 m were −41 m (95% CI −51 to −31) and −40 m (−53 to −27), n=40, P<0.05, both changes. At 1,650 m, day 1, 6MWD had changed by −22 m (−32 to −13), maximal oxygen uptake during bicycle exercise by −7% (−13 to 0) vs 490 m, P<0.05, both changes. At 490 m, 1,650 m, and 2,590 m, day 1, resting PaO2 were 9.0 (8.4; 9.4), 8.1 (7.5; 8.6), and 6.8 (6.3; 7.4) kPa, respectively, P<0.05 higher altitudes vs 490 m. While staying at higher altitudes, nine patients (24%) experienced symptoms or adverse health effects requiring oxygen therapy or relocation to lower altitude. Conclusion During sojourns at 1,650 m and 2,590 m, lowlanders with moderate to severe COPD experienced a mild reduction in exercise performance and nearly one quarter required oxygen therapy or descent to lower altitude because of adverse health effects. The findings may help to counsel COPD patients planning altitude travel. Registration ClinicalTrials.gov: NCT01875133
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Affiliation(s)
- Michael Furian
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
| | - Deborah Flueck
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
| | - Tsogyal D Latshang
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
| | - Philipp M Scheiwiller
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
| | | | | | - Christian Murer
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
| | - Adrian Steiner
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
| | - Thomas Rothe
- Zuercher RehaZentrum Davos, Davos Clavadel, Switzerland
| | - Malcolm Kohler
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
| | - Konrad E Bloch
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland,
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The influence of hypoxia and prolonged exercise on attentional performance at high and extreme altitudes: A pilot study. PLoS One 2018; 13:e0205285. [PMID: 30281651 PMCID: PMC6169942 DOI: 10.1371/journal.pone.0205285] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/21/2018] [Indexed: 12/13/2022] Open
Abstract
Introduction Exposure to hypoxic conditions is reported to impair cognitive performance. Further, moderate physical exercise improves cognitive function, but little is known about the influence of exercise on cognitive function in hypoxia. Therefore, the current study aimed to examine the influence of hypoxia (HYP) and prolonged exercise (EX) on attentional performance. Methods A total of 80 participants (female: n = 29; male: n = 51) were assigned to four groups: HYP + EX (n = 15), HYP (n = 25), EX (n = 21) and normoxia (NOR) (n = 21). The Frankfurt Attention Inventory—2 (FAIR-2) was performed at four testing points (day 1, 14, 16 and 18) to assess attentional performance. All groups completed a pretest (D1) and a follow-up test (D18). In HYP + EX conditions, the cognitive task was performed in a hypoxic state after prolonged exercise (D14: 3950 m, D16: 5739 m) during a mountain climb on Mt. Kilimanjaro. Participants in HYP were tested under intermittent hypoxia at rest in a hypoxic chamber (D14: 3500 m, D16: 5800 m), and those in EX were tested under normoxia after prolonged exercise during a 7-day backcountry ski hiking tour. NOR was a control group, and participants completed all tests under normoxia and at rest. Results Hypoxia impaired the attentional functions performance value (PV) and continuity value (CV) for the HYP + EX (p = 0.000) and HYP (L: p = 0.025; K: p = 0.043) groups at 5739 m and 5800 m, respectively, but not the function quality value (QV). In contrast, the EX group did not exhibit changes in attentional function. Conclusion The current results suggest that attentional performance is impaired during extreme normobaric and hypobaric hypoxic exposure. We further conclude that greater cognitive impairment under hypobaric hypoxia during a mountain climb compared with normobaric hypoxia at rest is not caused by prolonged exercise, but may be influenced by other factors (e.g. low temperatures, dehydration, or sleep deprivation) that remain to be verified.
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Pun M, Hartmann SE, Furian M, Dyck AM, Muralt L, Lichtblau M, Bader PR, Rawling JM, Ulrich S, Bloch KE, Poulin MJ. Effect of Acute, Subacute, and Repeated Exposure to High Altitude (5050 m) on Psychomotor Vigilance. Front Physiol 2018; 9:677. [PMID: 29915546 PMCID: PMC5994420 DOI: 10.3389/fphys.2018.00677] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/15/2018] [Indexed: 12/20/2022] Open
Abstract
Aim: High altitude (HA) hypoxia may affect cognitive performance and sleep quality. Further, vigilance is reduced following sleep deprivation. We investigated the effect on vigilance, actigraphic sleep indices, and their relationships with acute mountain sickness (AMS) during very HA exposure, acclimatization, and re-exposure. Methods: A total of 21 healthy altitude-naive individuals (25 ± 4 years; 13 females) completed 2 cycles of altitude exposure separated by 7 days at low altitude (LA, 520 m). Participants slept at 2900 m and spent the day at HA, (5050 m). We report acute altitude exposure on Day 1 (LA vs. HA1) and after 6 days of acclimatization (HA1 vs. HA6). Vigilance was quantified by reaction speed in the 10-min psychomotor vigilance test reaction speed (PVT-RS). AMS was evaluated using the Environmental Symptoms Questionnaire Cerebral Score (AMS-C score). Nocturnal rest/activity was recorded to estimate sleep duration using actigraphy. Results: In Cycle 1, PVT-RS was slower at HA1 compared to LA (4.1 ± 0.8 vs. 4.5 ± 0.6 s-1, respectively, p = 0.029), but not at HA6 (4.6 ± 0.7; p > 0.05). In Cycle 2, PVT-RS at HA1 (4.6 ± 0.7) and HA6 (4.8 ± 0.6) were not different from LA (4.8 ± 0.6, p > 0.05) and significantly greater than corresponding values in Cycle 1. In both cycles, AMS scores were higher at HA1 than at LA and HA6 (p < 0.05). Estimated sleep durations (TST) at LA, 1st and 5th nights were 431.3 ± 28.7, 418.1 ± 48.6, and 379.7 ± 51.4 min, respectively, in Cycle 1 and they were significantly reduced during acclimatization exposures (LA vs. 1st night, p > 0.05; LA vs. 5th night, p = 0.012; and 1st vs. 5th night, p = 0.054). LA, 1st and 5th nights TST in Cycle 2 were 477.5 ± 96.9, 430.9 ± 34, and 341.4 ± 32.2, respectively, and we observed similar deteriorations in TST as in Cycle 1 (LA vs. 1st night, p > 0.05; LA vs. 5th night, p = 0.001; and 1st vs. 5th night, p < 0.0001). At HA1, subjects who reported higher AMS-C scores exhibited slower PVT-RS (r = -0.56; p < 0.01). Subjects with higher AMS-C scores took longer time to react to the stimuli during acute exposure (r = 0.62, p < 0.01) during HA1 of Cycle 1. Conclusion: Acute exposure to HA reduces the PVT-RS. Altitude acclimatization over 6 days recovers the reaction speed and prevents impairments during subsequent altitude re-exposure after 1 week spent near sea level. However, acclimatization does not lead to improvement in total sleep time during acute and subacute exposures.
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Affiliation(s)
- Matiram Pun
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Sara E Hartmann
- Department of Physiology and 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 Zurich, Zurich, Switzerland
| | - Adrienna M Dyck
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Lara Muralt
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Mona Lichtblau
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Patrick R Bader
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Jean M Rawling
- Department of Family Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Silvia Ulrich
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Konrad E Bloch
- Pulmonary Division, Sleep Disorders Centre and Pulmonary Hypertension Clinic, University Hospital Zurich, Zurich, Switzerland
| | - Marc J Poulin
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.,Libin Cardiovascular Institute of Alberta, 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.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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Castellanos-Ramírez JC, Ruíz AJ, Hidalgo-Martínez P, Otero-Mendoza L. Sleep characteristics in an adult with sleep complaints in three cities at different altitudes. J Bras Pneumol 2018. [PMID: 29538546 PMCID: PMC6104543 DOI: 10.1590/s1806-37562016000000078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Sleep studies conducted at an altitude that is different from the home altitude can yield misleading results regarding the severity of obstructive sleep apnea (OSA). The objective of the present study was to determine the sleep characteristics of a patient undergoing polysomnography (PSG) in three Colombian cities at different altitudes (Bogotá, at 2,640 m above sea level [ASL]; Bucaramanga, at 959 m ASL; and Santa Marta, at 15 m ASL). The patient was an obese man with diabetes and suspected OSA. All PSG recordings were scored and interpreted in accordance with American Academy of Sleep Medicine criteria. In Bogotá, PSG revealed moderate OSA (an apnea-hypopnea index [AHI] of 21 events/h); in Bucaramanga, PSG revealed increased upper airway resistance (an AHI of 2 events/h); in Santa Marta, PSG revealed mild OSA (an AHI of 7 events/h). The reduction in the AHI was predominantly a reduction in hypopneas and obstructive apneas. The respiratory events were shorter in duration in the city at an intermediate altitude. Given that the AHI varied widely across cities, we can assume that the patient is normal or has moderate OSA depending on the city where he is. Central apneas were found to have no influence on the AHI.
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Affiliation(s)
| | - Alvaro J Ruíz
- . Departamento de Medicina Interna, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia.,. Departamento de Epidemiología Clínica y Bioestadística, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Patricia Hidalgo-Martínez
- . Hospital Universitario San Ignacio, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia.,. Departamento de Medicina Interna, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Liliana Otero-Mendoza
- . Facultad de Odontología, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
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Grissom CK, Jones BE. Respiratory Health Benefits and Risks of Living at Moderate Altitude. High Alt Med Biol 2017; 19:109-115. [PMID: 28375663 DOI: 10.1089/ham.2016.0142] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Grissom, Colin K., and Barbara E. Jones. Respiratory health benefits and risks of living at moderate altitude. High Alt Med Biol 19:109-115, 2018.-The respiratory system plays a critical role in the series of physiologic responses that occur at high altitude and allows individuals to adapt to and tolerate hypobaric hypoxia. Persons with underlying lung disease may have complications, but sometimes derive benefits, related to residence at high altitude. This review will focus on health benefits and risks of patients with underlying asthma, chronic obstructive pulmonary disease, pulmonary hypertension, or obstructive sleep apnea, who live at altitudes of 1500 to 4500 m. We will also discuss maladaptive responses of the respiratory system at high altitude in previously healthy persons, including development of pulmonary hypertension and sleep-disordered breathing.
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Affiliation(s)
- Colin K Grissom
- 1 Pulmonary and Critical Care Medicine, Intermountain Medical Center , Murray, Utah.,2 Pulmonary and Critical Care Medicine, The University of Utah , Salt Lake City, Utah
| | - Barbara E Jones
- 2 Pulmonary and Critical Care Medicine, The University of Utah , Salt Lake City, Utah.,3 Pulmonary and Critical Care Medicine, Salt Lake City Veterans Affairs Health System , Salt Lake City, Utah
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Horiuchi M, Oda S, Uno T, Endo J, Handa Y, Fukuoka Y. Effects of Short-Term Acclimatization at the Summit of Mt. Fuji (3776 m) on Sleep Efficacy, Cardiovascular Responses, and Ventilatory Responses. High Alt Med Biol 2017; 18:171-178. [PMID: 28375664 DOI: 10.1089/ham.2016.0162] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Horiuchi, Masahiro, Shiro Oda, Tadashi Uno, Junko Endo, Yoko Handa, and Yoshiyuki Fukuoka. Effects of short-term acclimatization at the summit of Mt. Fuji (3776 m) on sleep efficacy, cardiovascular responses, and ventilatory responses. High Alt Med Biol. 18:171-178, 2017.-We investigated the effects of a short period of acclimatization, at 3776 m on Mt. Fuji, on sleep parameters and related physiological responses. Physiological responses were assessed in seven healthy lowlander men during both daytime and sleep while at sea level (SL), as well as for three consecutive nights at high altitude (HA; 3776 m, day 1 [D1], D2, D3, and morning only of D4). Blood pressure variables, heart rate (HR), pulmonary ventilation (VE), and breathing frequency (Bf) progressively increased each day, with significant differences between SL and HA (p < 0.05, respectively). In contrast, end-tidal PCO2 (PETCO2) progressively decreased each day with statistical differences between SL and D3 at HA (p < 0.05). During sleep at HA, mean arterial pressure (MAP) was stable, whereas it decreased during sleep at SL. Sleep efficacy, which was assessed by actigraphy, was linearly impaired with statistical differences between SL and D3 (p < 0.05). These impairments in sleep efficacy at HA were associated with higher MAP and HR, as well as lower Bf and PETCO2 during the daytime (pooled data, p < 0.05, respectively). These results suggest that hypoxia-induced cardiovascular and ventilatory responses may be crucial contributors to changes in sleep efficacy at HA.
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Affiliation(s)
- Masahiro Horiuchi
- 1 Division of Human Environmental Science, Mt. Fuji Research Institute , Yamanashi, Japan
| | - Shiro Oda
- 2 Department of Health and Welfare, School of Life Long Sport, Hokusho University , Hokkaido, Japan
| | - Tadashi Uno
- 1 Division of Human Environmental Science, Mt. Fuji Research Institute , Yamanashi, Japan
| | - Junko Endo
- 1 Division of Human Environmental Science, Mt. Fuji Research Institute , Yamanashi, Japan
| | - Yoko Handa
- 1 Division of Human Environmental Science, Mt. Fuji Research Institute , Yamanashi, Japan
| | - Yoshiyuki Fukuoka
- 3 Faculty of Health and Sports Science, Doshisha University , Kyoto, Japan
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Randerath W, Verbraecken J, Andreas S, Arzt M, Bloch KE, Brack T, Buyse B, De Backer W, Eckert DJ, Grote L, Hagmeyer L, Hedner J, Jennum P, La Rovere MT, Miltz C, McNicholas WT, Montserrat J, Naughton M, Pepin JL, Pevernagie D, Sanner B, Testelmans D, Tonia T, Vrijsen B, Wijkstra P, Levy P. Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep. Eur Respir J 2016; 49:13993003.00959-2016. [DOI: 10.1183/13993003.00959-2016] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/25/2016] [Indexed: 02/07/2023]
Abstract
The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerge under positive airway pressure treatment or opioid use, or at high altitude. As yet, there is insufficient knowledge on the clinical features, pathophysiological background and consecutive algorithms for stepped-care treatment. Most recently, it has been discussed intensively if CSA in heart failure is a “marker” of disease severity or a “mediator” of disease progression, and if and which type of positive airway pressure therapy is indicated. In addition, disturbances of respiratory drive or the translation of central impulses may result in hypoventilation, associated with cerebral or neuromuscular diseases, or severe diseases of lung or thorax. These statements report the results of an European Respiratory Society Task Force addressing actual diagnostic and therapeutic standards. The statements are based on a systematic review of the literature and a systematic two-step decision process. Although the Task Force does not make recommendations, it describes its current practice of treatment of CSA in heart failure and hypoventilation.
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48
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Orr JE, Malhotra A, Sands SA. Pathogenesis of central and complex sleep apnoea. Respirology 2016; 22:43-52. [PMID: 27797160 DOI: 10.1111/resp.12927] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 09/22/2016] [Accepted: 10/03/2016] [Indexed: 12/01/2022]
Abstract
Central sleep apnoea (CSA) - the temporary absence or diminution of ventilatory effort during sleep - is seen in a variety of forms including periodic breathing in infancy and healthy adults at altitude and Cheyne-Stokes respiration in heart failure. In most circumstances, the cyclic absence of effort is paradoxically a consequence of hypersensitive ventilatory chemoreflex responses to oppose changes in airflow, that is elevated loop gain, leading to overshoot/undershoot ventilatory oscillations. Considerable evidence illustrates overlap between CSA and obstructive sleep apnoea (OSA), including elevated loop gain in patients with OSA and the presence of pharyngeal narrowing during central apnoeas. Indeed, treatment of OSA, whether via continuous positive airway pressure (CPAP), tracheostomy or oral appliances, can reveal CSA, an occurrence referred to as complex sleep apnoea. Factors influencing loop gain include increased chemosensitivity (increased controller gain), reduced damping of blood gas levels (increased plant gain) and increased lung to chemoreceptor circulatory delay. Sleep-wake transitions and pharyngeal dilator muscle responses effectively raise the controller gain and therefore also contribute to total loop gain and overall instability. In some circumstances, for example apnoea of infancy and central congenital hypoventilation syndrome, central apnoeas are the consequence of ventilatory depression and defective ventilatory responses, that is low loop gain. The efficacy of available treatments for CSA can be explained in terms of their effects on loop gain, for example CPAP improves lung volume (plant gain), stimulants reduce the alveolar-inspired PCO2 difference and supplemental oxygen lowers chemosensitivity. Understanding the magnitude of loop gain and the mechanisms contributing to instability may facilitate personalized interventions for CSA.
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Affiliation(s)
- Jeremy E Orr
- Division of Pulmonary and Critical Care Medicine, University of California San Diego, La Jolla, California, USA
| | - Atul Malhotra
- Division of Pulmonary and Critical Care Medicine, University of California San Diego, La Jolla, California, USA
| | - Scott A Sands
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Department of Allergy Immunology and Respiratory Medicine and Central Clinical School, The Alfred and Monash University, Melbourne, Victoria, Australia
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Saugy JJ, Schmitt L, Fallet S, Faiss R, Vesin JM, Bertschi M, Heinzer R, Millet GP. Sleep Disordered Breathing During Live High-Train Low in Normobaric Versus Hypobaric Hypoxia. High Alt Med Biol 2016; 17:233-238. [PMID: 27410774 DOI: 10.1089/ham.2016.0049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Saugy, Jonas J., Laurent Schmitt, Sibylle Fallet, Raphael Faiss, Jean-Marc Vesin, Mattia Bertschi, Raphaël Heinzer, and Grégoire P. Millet. Sleep disordered breathing during live high-train low in normobaric versus hypobaric hypoxia. High Alt Med Biol. 17:233-238, 2016.-The present study aimed to compare sleep disordered breathing during live high-train low (LHTL) altitude camp using normobaric hypoxia (NH) and hypobaric hypoxia (HH). Sixteen highly trained triathletes completed two 18-day LHTL camps in a crossover designed study. They trained at 1100-1200 m while they slept either in NH at a simulated altitude of 2250 m or in HH. Breathing frequency and oxygen saturation (SpO2) were recorded continuously during all nights and oxygen desaturation index (ODI 3%) calculated. Breathing frequency was lower for NH than HH during the camps (14.6 ± 3.1 breath × min-1 vs. 17.2 ± 3.4 breath × min-1, p < 0.001). SpO2 was lower for HH than NH (90.8 ± 0.3 vs. 91.9 ± 0.2, p < 0.001) and ODI 3% was higher for HH than NH (15.1 ± 3.5 vs. 9.9 ± 1.6, p < 0.001). Sleep in moderate HH is more altered than in NH during a LHTL camp.
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Affiliation(s)
- Jonas J Saugy
- 1 Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne , Switzerland .,2 Department of Physiology, Faculty of Biology and Medicine, University of Lausanne , Switzerland
| | - Laurent Schmitt
- 3 National School of Mountain Sports/National Ski-Nordic Centre , Prémanon, France
| | - Sibylle Fallet
- 4 Institute of Electrical Engineering, Swiss Federal Institute of Technology , Lausanne, Switzerland
| | - Raphael Faiss
- 1 Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne , Switzerland
| | - Jean-Marc Vesin
- 4 Institute of Electrical Engineering, Swiss Federal Institute of Technology , Lausanne, Switzerland
| | - Mattia Bertschi
- 5 Swiss Center for Electronics and Microtechnology , CSEM, Neuchâtel, Switzerland
| | - Raphaël Heinzer
- 6 Center for Investigation and Research in Sleep , CHUV, Lausanne, Switzerland
| | - Grégoire P Millet
- 1 Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne , Switzerland .,2 Department of Physiology, Faculty of Biology and Medicine, University of Lausanne , Switzerland
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50
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Latshang TD, Mueller DJ, Lo Cascio CM, Stöwhas AC, Stadelmann K, Tesler N, Achermann P, Huber R, Kohler M, Bloch KE. Actigraphy of Wrist and Ankle for Measuring Sleep Duration in Altitude Travelers. High Alt Med Biol 2016; 17:194-202. [PMID: 27383065 DOI: 10.1089/ham.2016.0006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Latshang, Tsogyal Daniela, Daniela Juliana Mueller, Christian Maurizio Lo Cascio, Anne-Christin Stöwhas, Katrin Stadelmann, Noemi Tesler, Peter Achermann, Reto Huber, Malcolm Kohler, and Konrad Ernst Bloch. Actigraphy of wrist and ankle for measuring sleep duration in altitude travelers. High Alt Med Biol. 17:194-202, 2016-Aims: Actigraphy might be convenient to assess sleep disturbances in altitude field studies. Therefore, we evaluated whether actigraphy accurately measures sleep duration in healthy subjects traveling to altitude. METHODS Fifty-one healthy men, aged mean ± standard deviation (SD) 27 ± 9 years, were studied during one night at Zurich (490 m), two nights at Davos Wolfgang (1630 m), and two nights at Jakobshorn (2590 m), in randomized order. Sleep duration measured by actigraphy, using a one-axis device at the wrist (n = 51), a three-axis device at the other wrist, and a three-axis device at the ankle (n = 22), was compared with corresponding total sleep time (TST) measured by polysomnography. RESULTS During 255 polysomnographic overnight studies, 449 paired actigraphic recordings were obtained. The median polysomnographic-derived TST ranged from 397 to 408 minutes. Actigraphic mean TST from wrists with one-axis and three-axis devices, and from ankle agreed well with polysomnographic values with a bias of +1, -7, +6 minutes, respectively. Corresponding limits of agreement (±2 SD of bias) were ±51, ±60, and ±59 minutes. Limits of agreement of mean TST over five nights by actigraphy and polysomnography were similar to the coefficient of repeatability (2 SD of mean) of polysomnographic TST, that is, ±31, ±38, and ±36 minutes versus ±34 minutes. CONCLUSIONS Actigraphy of the wrist or ankle by a one-axis or a three-axis device accurately estimates mean TST in groups of subjects and mean TST over several nights in individuals traveling to altitude. Therefore, actigraphy is valuable for assessing effects of altitude and other environmental influences on sleep duration during field studies over extended periods.
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Affiliation(s)
- Tsogyal Daniela Latshang
- 1 Pulmonary Division, Sleep Disorders Center, University Hospital of Zurich , Zurich, Switzerland .,2 Zurich Center for Interdisciplinary Sleep Research, University of Zurich , Zurich, Switzerland
| | - Daniela Juliana Mueller
- 1 Pulmonary Division, Sleep Disorders Center, University Hospital of Zurich , Zurich, Switzerland
| | | | - Anne-Christin Stöwhas
- 1 Pulmonary Division, Sleep Disorders Center, University Hospital of Zurich , Zurich, Switzerland
| | - Katrin Stadelmann
- 3 Institute of Pharmacology and Toxicology, University of Zurich , Zurich, Switzerland
| | - Noemi Tesler
- 4 Child Development Center and Pediatric Sleep Disorders Center, University Children's Hospital , Zurich, Zurich, Switzerland
| | - Peter Achermann
- 2 Zurich Center for Interdisciplinary Sleep Research, University of Zurich , Zurich, Switzerland .,3 Institute of Pharmacology and Toxicology, University of Zurich , Zurich, Switzerland .,5 Zurich Center for Integrative Human Physiology, University of Zurich , Zurich, Switzerland
| | - Reto Huber
- 2 Zurich Center for Interdisciplinary Sleep Research, University of Zurich , Zurich, Switzerland .,4 Child Development Center and Pediatric Sleep Disorders Center, University Children's Hospital , Zurich, Zurich, Switzerland .,5 Zurich Center for Integrative Human Physiology, University of Zurich , Zurich, Switzerland
| | - Malcolm Kohler
- 1 Pulmonary Division, Sleep Disorders Center, University Hospital of Zurich , Zurich, Switzerland .,2 Zurich Center for Interdisciplinary Sleep Research, University of Zurich , Zurich, Switzerland .,5 Zurich Center for Integrative Human Physiology, University of Zurich , Zurich, Switzerland
| | - Konrad Ernst Bloch
- 1 Pulmonary Division, Sleep Disorders Center, University Hospital of Zurich , Zurich, Switzerland .,2 Zurich Center for Interdisciplinary Sleep Research, University of Zurich , Zurich, Switzerland .,5 Zurich Center for Integrative Human Physiology, University of Zurich , Zurich, Switzerland
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