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Chen Y, Zhang D, Wu Y, Jiang W, Guo L, Pan D, He Q, Yin Z, Sun L, Wang S. Chronic intermittent hypoxia alleviates alcohol-related liver injury via downregulation of hepatic hypoxia-inducible factor-2α. Am J Physiol Gastrointest Liver Physiol 2025; 328:G610-G623. [PMID: 40243734 DOI: 10.1152/ajpgi.00283.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2024] [Revised: 11/17/2024] [Accepted: 04/02/2025] [Indexed: 04/18/2025]
Abstract
Alcohol-related liver disease (ALD) is one of the leading causes of alcohol-related morbidity and mortality worldwide. Unfortunately, limited therapeutic options are currently available, due to the complex risk factors involved as well as the lack of information on the molecular mechanisms driving its progression. Interestingly, chronic, excessive alcohol intake has been reported to exacerbate the severity of obstructive sleep apnea (OSA), a respiratory disorder typically characterized by chronic intermittent hypoxia (CIH). However, this relationship between alcohol-enhanced OSA and ALD development/progression remains to be elucidated. As an approach to investigate this relationship, in vivo Gao-binge ALD and CIH mouse models were established. Alcohol-related liver injury, hepatic steatosis, inflammation, and oxidative stress were then assessed in these models. In addition, lipopolysaccharide (LPS) and ethanol-cotreated mouse normal hepatocyte cell line AML12 served as an in vitro model to investigate the mechanisms through which CIH affects ethanol-induced liver injury. CIH intervention ameliorated alcohol-related liver injury, reduced hepatic lipid accumulation and oxidative stress, and alleviated liver inflammation. Mechanistically, in the liver of these Gao-binge mice, CIH intervention inhibited alcohol-induced upregulation and activation of hypoxia-inducible factor 2α (HIF-2α), a protein which plays a key role in hepatic lipid metabolism and liver injury. Similar to these effects observed in response to CIH intervention, treatment of Gao-binge mice with the selective inhibitor of HIF-2α, PT2385, alleviated alcohol-related liver injury and steatosis while inhibiting oxidative stress and inflammation. Additional findings from our in vitro model revealed that CIH downregulated HIF-2α by promoting calpains protein expression, thereby reducing the accumulation of lipid droplets and decreasing reactiveoxygenspecies (ROS) production in AML12 cells co-challenged with LPS and ethanol. The above results provide important, new evidence that reconceptualizes the role of alcohol-enhanced OSA in ALD progression. Moreover, these findings can serve as the foundation for the development of HIF-2α inhibitors for use in the prevention and treatment of ALD.NEW & NOTEWORTHY Chronic intermittent hypoxia (CIH) intervention mitigated hepatic lipid accumulation and reduced hepatic injury, inflammation, and oxidative stress in alcohol-related liver disease (ALD) mice. CIH alleviates ALD and is likely linked to the downregulation of hypoxia-inducible factor 2α (HIF-2α) expression mediated by calpains. This study presents a new possibility for ALD treatment and lays a theoretical foundation for the clinical treatment of ALD.
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Affiliation(s)
- Yunling Chen
- Science and Technology Innovation Center, Shandong First Medical University, Jinan, People's Republic of China
- Medical School, Nankai University, Tianjin, People's Republic of China
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Shandong University, Jinan, People's Republic of China
| | - Dongyuan Zhang
- Department of General Surgery, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, People's Republic of China
| | - Yunxiao Wu
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Shandong University, Jinan, People's Republic of China
| | - Wenshan Jiang
- Science and Technology Innovation Center, Shandong First Medical University, Jinan, People's Republic of China
| | - Luoting Guo
- Science and Technology Innovation Center, Shandong First Medical University, Jinan, People's Republic of China
| | - Di Pan
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Shandong University, Jinan, People's Republic of China
| | - Qiao He
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Shandong University, Jinan, People's Republic of China
| | - Zhaoqing Yin
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Shandong University, Jinan, People's Republic of China
| | - Lichao Sun
- Emergency Department, China-Japan Friendship Hospital, Beijing, People's Republic of China
| | - Shuanglian Wang
- Science and Technology Innovation Center, Shandong First Medical University, Jinan, People's Republic of China
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Kapel JS, Stokholm R, Elmengaard B, Nochi Z, Olsen RJ, Foldager CB. Individualized Algorithm-Based Intermittent Hypoxia Improves Quality of Life in Patients Suffering from Long-Term Sequelae After COVID-19 Infection. J Clin Med 2025; 14:1590. [PMID: 40095507 PMCID: PMC11900126 DOI: 10.3390/jcm14051590] [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: 01/23/2025] [Revised: 02/17/2025] [Accepted: 02/21/2025] [Indexed: 03/19/2025] Open
Abstract
Background/Objectives: Post-COVID-19 condition (PCC), also known as long COVID, has emerged as a recognized syndrome affecting millions of people worldwide, significantly impairing their quality of life. Currently, no effective therapeutic options are available to manage this condition. The objective of the present study was to evaluate the long-term effects of personalized, algorithm-based intermittent hypoxia-hyperoxia conditioning (IHHC) on quality of life and pain in patients with PCC. Methods: This open-label cohort study included 199 PCC patients, aged 11-87 years (female-to-male ratio: 67:33) and experiencing moderate-to-severe fatigue, between 1 January 2020 and 31 December 2023. Each patient received an algorithm-based treatment plan tailored to their demographics, symptom duration, and baseline pain (NRS) and quality of life (SF-36) scores. Patients received an average of six treatment sessions (range: 2-21), each consisting of intermittent hypoxic-hyperoxic cycles, with hypoxia (9-13% O2) lasting 3-8 min and hyperoxia (34-36% O2) lasting 1-3 min. The primary outcomes were changes in the NRS and SF-36 scores at the 6-week and 6-month follow-ups. Results: At the 6-week follow-up after treatment initiation, the SF-36 scores increased by 102 points (p < 0.001, 95% CI: 78.4-127), and this improvement persisted at the 6-month follow-up (Δ106, p < 0.001, 95% CI: 57.0-154). Pain was reduced by 28-32% at both follow-up time points, exceeding the clinically relevant threshold. Health transition scores indicated a patient-perceived improvement in health status. Conclusions: In this study, a personalized, algorithm-based IHHC alleviated pain and improved quality of life in patients suffering from persistent long-term sequelae after COVID-19 infection. The effects were sustained for up to six months. Further research is warranted to elucidate the mechanisms underlying IHHC's therapeutic effects in this patient population.
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Affiliation(s)
| | | | | | - Zahra Nochi
- Research Unit for Molecular Medicine, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, 8200 Aarhus N, Denmark
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark
| | - Rikke Jentoft Olsen
- Research Unit for Molecular Medicine, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, 8200 Aarhus N, Denmark
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Burtscher J, Denti V, Gostner JM, Weiss AK, Strasser B, Hüfner K, Burtscher M, Paglia G, Kopp M, Dünnwald T. The interplay of NAD and hypoxic stress and its relevance for ageing. Ageing Res Rev 2025; 104:102646. [PMID: 39710071 DOI: 10.1016/j.arr.2024.102646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2024] [Revised: 12/17/2024] [Accepted: 12/17/2024] [Indexed: 12/24/2024]
Abstract
Nicotinamide adenine dinucleotide (NAD) is an essential regulator of cellular metabolism and redox processes. NAD levels and the dynamics of NAD metabolism change with increasing age but can be modulated via the diet or medication. Because NAD metabolism is complex and its regulation still insufficiently understood, achieving specific outcomes without perturbing delicate balances through targeted pharmacological interventions remains challenging. NAD metabolism is also highly sensitive to environmental conditions and can be influenced behaviorally, e.g., by exercise. Changes in oxygen availability directly and indirectly affect NAD levels and may result from exposure to ambient hypoxia, increased oxygen demand during exercise, ageing or disease. Cellular responses to hypoxic stress involve rapid alterations in NAD metabolism and depend on many factors, including age, glucose status, the dose of the hypoxic stress and occurrence of reoxygenation phases, and exhibit complex time-courses. Here we summarize the known determinants of NAD-regulation by hypoxia and evaluate the role of NAD in hypoxic stress. We define the specific NAD responses to hypoxia and identify a great potential of the modulation of NAD metabolism regarding hypoxic injuries. In conclusion, NAD metabolism and cellular hypoxia responses are strongly intertwined and together mediate protective processes against hypoxic insults. Their interactions likely contribute to age-related changes and vulnerabilities. Targeting NAD homeostasis presents a promising avenue to prevent/treat hypoxic insults and - conversely - controlled hypoxia is a potential tool to regulate NAD homeostasis.
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Affiliation(s)
- Johannes Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria.
| | - Vanna Denti
- School of Medicine and Surgery, University of Milano-Bicocca, Vedano al Lambro, MB, Italy
| | - Johanna M Gostner
- Medical University of Innsbruck, Biocenter, Institute of Medical Biochemistry, Innsbruck, Austria
| | - Alexander Kh Weiss
- Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria
| | - Barbara Strasser
- Ludwig Boltzmann Institute for Rehabilitation Research, Vienna, Austria; Faculty of Medicine, Sigmund Freud Private University, Vienna, Austria
| | - Katharina Hüfner
- Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, University Hospital for Psychiatry II, Medical University of Innsbruck, Innsbruck, Austria
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Giuseppe Paglia
- School of Medicine and Surgery, University of Milano-Bicocca, Vedano al Lambro, MB, Italy
| | - Martin Kopp
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Tobias Dünnwald
- Institute for Sports Medicine, Alpine Medicine and Health Tourism (ISAG), UMIT TIROL - Private University for Health Sciences and Health Technology, Hall in Tirol, Austria
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Rogers RS, Mootha VK. Hypoxia as a medicine. Sci Transl Med 2025; 17:eadr4049. [PMID: 39841808 DOI: 10.1126/scitranslmed.adr4049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Accepted: 12/31/2024] [Indexed: 01/24/2025]
Abstract
Oxygen is essential for human life, yet a growing body of preclinical research is demonstrating that chronic continuous hypoxia can be beneficial in models of mitochondrial disease, autoimmunity, ischemia, and aging. This research is revealing exciting new and unexpected facets of oxygen biology, but translating these findings to patients poses major challenges, because hypoxia can be dangerous. Overcoming these barriers will require integrating insights from basic science, high-altitude physiology, clinical medicine, and sports technology. Here, we explore the foundations of this nascent field and outline a path to determine how chronic continuous hypoxia can be safely, effectively, and practically delivered to patients.
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Affiliation(s)
- Robert S Rogers
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Broad Institute, Cambridge, MA 02142, USA
| | - Vamsi K Mootha
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Broad Institute, Cambridge, MA 02142, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Boston, MA 02114, USA
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Panza GS, Soltesz AE, Zhao F, Fritz NE, Delgado AD, Sutor TW. Intermittent hypoxia and motor learning: new information and new questions. J Physiol 2025; 603:595-597. [PMID: 39470714 DOI: 10.1113/jp287594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/30/2024] Open
Affiliation(s)
- Gino S Panza
- Department of Health Care Sciences, Program of Occupational Therapy, Wayne State University, Detroit, MI, USA
- Translational Neuroscience Program, Wayne State University School of Medicine, Detroit, MI, USA
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
| | - Alexandra E Soltesz
- Translational Neuroscience Program, Wayne State University School of Medicine, Detroit, MI, USA
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
| | - Fei Zhao
- Department of Health Care Sciences, Program of Occupational Therapy, Wayne State University, Detroit, MI, USA
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
| | - Nora E Fritz
- Translational Neuroscience Program, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Health Care Sciences, Program of Physical Therapy, Wayne State University, Detroit, MI, USA
- Department of Neurology, Wayne State University, Detroit, MI, USA
| | - Andrew D Delgado
- Department of Population Health Science & Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Tommy W Sutor
- Center for Breathing Research and Therapeutics and Department of Physical Therapy, University of Florida, Gainesville, FL, USA
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Burtscher J, Citherlet T, Camacho-Cardenosa A, Camacho-Cardenosa M, Raberin A, Krumm B, Hohenauer E, Egg M, Lichtblau M, Müller J, Rybnikova EA, Gatterer H, Debevec T, Baillieul S, Manferdelli G, Behrendt T, Schega L, Ehrenreich H, Millet GP, Gassmann M, Schwarzer C, Glazachev O, Girard O, Lalande S, Hamlin M, Samaja M, Hüfner K, Burtscher M, Panza G, Mallet RT. Mechanisms underlying the health benefits of intermittent hypoxia conditioning. J Physiol 2024; 602:5757-5783. [PMID: 37860950 DOI: 10.1113/jp285230] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 10/11/2023] [Indexed: 10/21/2023] Open
Abstract
Intermittent hypoxia (IH) is commonly associated with pathological conditions, particularly obstructive sleep apnoea. However, IH is also increasingly used to enhance health and performance and is emerging as a potent non-pharmacological intervention against numerous diseases. Whether IH is detrimental or beneficial for health is largely determined by the intensity, duration, number and frequency of the hypoxic exposures and by the specific responses they engender. Adaptive responses to hypoxia protect from future hypoxic or ischaemic insults, improve cellular resilience and functions, and boost mental and physical performance. The cellular and systemic mechanisms producing these benefits are highly complex, and the failure of different components can shift long-term adaptation to maladaptation and the development of pathologies. Rather than discussing in detail the well-characterized individual responses and adaptations to IH, we here aim to summarize and integrate hypoxia-activated mechanisms into a holistic picture of the body's adaptive responses to hypoxia and specifically IH, and demonstrate how these mechanisms might be mobilized for their health benefits while minimizing the risks of hypoxia exposure.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Tom Citherlet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Alba Camacho-Cardenosa
- Department of Physical Education and Sports, Faculty of Sports Science, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
| | - Marta Camacho-Cardenosa
- Clinical Management Unit of Endocrinology and Nutrition - GC17, Maimónides Biomedical Research Institute of Cordoba (IMIBIC), Reina Sofía University Hospital, Córdoba, Spain
| | - Antoine Raberin
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Bastien Krumm
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Erich Hohenauer
- Rehabilitation and Exercise Science Laboratory (RES lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland
- International University of Applied Sciences THIM, Landquart, Switzerland
- Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland
| | - Margit Egg
- Institute of Zoology, University of Innsbruck, Innsbruck, Austria
| | - Mona Lichtblau
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
| | - Julian Müller
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
| | - Elena A Rybnikova
- Pavlov Institute of Physiology, Russian Academy of Sciences, St Petersburg, Russia
| | - Hannes Gatterer
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
- Institute for Sports Medicine, Alpine Medicine and Health Tourism (ISAG), UMIT TIROL-Private University for Health Sciences and Health Technology, Hall in Tirol, Austria
| | - Tadej Debevec
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
- Department of Automatics, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Sebastien Baillieul
- Service Universitaire de Pneumologie Physiologie, University of Grenoble Alpes, Inserm, Grenoble, France
| | | | - Tom Behrendt
- Chair Health and Physical Activity, Department of Sport Science, Institute III, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Lutz Schega
- Chair Health and Physical Activity, Department of Sport Science, Institute III, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Hannelore Ehrenreich
- Clinical Neuroscience, University Medical Center and Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
- Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru
| | - Christoph Schwarzer
- Institute of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Oleg Glazachev
- Department of Normal Physiology, N.V. Sklifosovsky Institute of Clinical Medicine, I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Western Australia, Australia
| | - Sophie Lalande
- Department of Kinesiology and Health Education, University of Texas at Austin, Austin, TX, USA
| | - Michael Hamlin
- Department of Tourism, Sport and Society, Lincoln University, Christchurch, New Zealand
| | - Michele Samaja
- Department of Health Science, University of Milan, Milan, Italy
| | - Katharina Hüfner
- Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, University Hospital for Psychiatry II, Medical University of Innsbruck, Innsbruck, Austria
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Gino Panza
- The Department of Health Care Sciences, Program of Occupational Therapy, Wayne State University, Detroit, MI, USA
- John D. Dingell VA Medical Center Detroit, Detroit, MI, USA
| | - Robert T Mallet
- Department of Physiology & Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
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Karakasis P, Sagris M, Patoulias D, Koufakis T, Theofilis P, Klisic A, Fragakis N, El Tanani M, Rizzo M. Mitigating Increased Cardiovascular Risk in Patients with Obstructive Sleep Apnea Using GLP-1 Receptor Agonists and SGLT2 Inhibitors: Hype or Hope? Biomedicines 2024; 12:2503. [PMID: 39595069 PMCID: PMC11591904 DOI: 10.3390/biomedicines12112503] [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: 10/15/2024] [Revised: 10/27/2024] [Accepted: 10/30/2024] [Indexed: 11/28/2024] Open
Abstract
Obstructive sleep apnea (OSA) is a prevalent condition associated with increased cardiovascular risk, particularly in individuals with comorbid obesity and type 2 diabetes (T2D). Despite the widespread use of continuous positive airway pressure (CPAP) for OSA management, adherence remains suboptimal, and CPAP has not consistently demonstrated reductions in surrogate cardiovascular events. Recently, attention has focused on glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 (SGLT2) inhibitors as potential therapeutic agents for mitigating cardiovascular risk in OSA patients. These agents, originally developed for T2D management, have demonstrated pleiotropic effects, including significant weight loss, blood pressure reduction, and amelioration of endothelial dysfunction and arterial stiffness, along with anti-inflammatory benefits, which may be particularly beneficial in OSA. Emerging clinical evidence suggests that GLP-1RAs and SGLT2 inhibitors can reduce OSA severity and improve daytime sleepiness, potentially reversing the adverse cardiovascular effects observed in OSA. This review explores the pathophysiological mechanisms linking OSA with cardiovascular disease and evaluates the potential therapeutic roles of GLP-1RAs and SGLT2 inhibitors in addressing cardiovascular risk in OSA patients. Further research, including long-term clinical trials, is necessary to establish the effectiveness of these therapies in reducing cardiovascular events and improving patients' reported outcomes in this population.
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Affiliation(s)
- Paschalis Karakasis
- Second Department of Cardiology, Hippokration General Hospital, Aristotle University of Thessaloniki, 54642 Thessaloniki, Greece;
| | - Marios Sagris
- First Cardiology Department, School of Medicine, Hippokration General Hospital, National and Kapodistrian University of Athens, 15772 Athens, Greece; (M.S.); (P.T.)
| | - Dimitrios Patoulias
- Second Propedeutic Department of Internal Medicine, Faculty of Medicine, School of Health Sciences Aristotle, University of Thessaloniki, 54642 Thessaloniki, Greece; (D.P.); (T.K.)
| | - Theocharis Koufakis
- Second Propedeutic Department of Internal Medicine, Faculty of Medicine, School of Health Sciences Aristotle, University of Thessaloniki, 54642 Thessaloniki, Greece; (D.P.); (T.K.)
| | - Panagiotis Theofilis
- First Cardiology Department, School of Medicine, Hippokration General Hospital, National and Kapodistrian University of Athens, 15772 Athens, Greece; (M.S.); (P.T.)
| | - Aleksandra Klisic
- Primary Health Care Center, Faculty of Medicine, University of Montenegro, 81000 Podgorica, Montenegro;
| | - Nikolaos Fragakis
- Second Department of Cardiology, Hippokration General Hospital, Aristotle University of Thessaloniki, 54642 Thessaloniki, Greece;
| | - Mohamed El Tanani
- Ras Al Khaimah Medical and Health Sciences University, Ras Al Khaimah P.O. Box 11172, United Arab Emirates; (M.E.T.); (M.R.)
| | - Manfredi Rizzo
- Ras Al Khaimah Medical and Health Sciences University, Ras Al Khaimah P.O. Box 11172, United Arab Emirates; (M.E.T.); (M.R.)
- School of Medicine, Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties (Promise), University of Palermo, 90100 Palermo, Italy
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Flores K, Almeida C, Arriaza K, Pena E, El Alam S. mTOR in the Development of Hypoxic Pulmonary Hypertension Associated with Cardiometabolic Risk Factors. Int J Mol Sci 2024; 25:11023. [PMID: 39456805 PMCID: PMC11508063 DOI: 10.3390/ijms252011023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2024] [Revised: 10/08/2024] [Accepted: 10/10/2024] [Indexed: 10/28/2024] Open
Abstract
The pathophysiology of pulmonary hypertension is complex and multifactorial. It is a disease characterized by increased pulmonary vascular resistance at the level due to sustained vasoconstriction and remodeling of the pulmonary arteries, which triggers an increase in the mean pulmonary artery pressure and subsequent right ventricular hypertrophy, which in some cases can cause right heart failure. Hypoxic pulmonary hypertension (HPH) is currently classified into Group 3 of the five different groups of pulmonary hypertensions, which are determined according to the cause of the disease. HPH mainly develops as a product of lung diseases, among the most prevalent causes of obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD), or hypobaric hypoxia due to exposure to high altitudes. Additionally, cardiometabolic risk factors converge on molecular mechanisms involving overactivation of the mammalian target of rapamycin (mTOR), which correspond to a central axis in the development of HPH. The aim of this review is to summarize the role of mTOR in the development of HPH associated with metabolic risk factors and its therapeutic alternatives, which will be discussed in this review.
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Affiliation(s)
| | | | - Karem Arriaza
- High Altitude Medicine Research Center (CEIMA), Arturo Prat University, Iquique 1110939, Chile; (K.F.); (C.A.); (E.P.); (S.E.A.)
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Zha S, Liu X, Yao Y, He Y, Wang Y, Zhang Q, Zhang J, Yi Y, Xiao R, Hu K. Short-term intermittent hypoxia exposure for dyspnea and fatigue in post-acute sequelae of COVID-19: A randomized controlled study. Respir Med 2024; 232:107763. [PMID: 39127085 DOI: 10.1016/j.rmed.2024.107763] [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: 03/07/2024] [Revised: 06/20/2024] [Accepted: 08/07/2024] [Indexed: 08/12/2024]
Abstract
BACKGROUND Post-acute sequelae of COVID-19 (PASC) is incurring a huge health and economic burden worldwide. There is currently no effective treatment or recommended drug for PASC. METHODS This prospective randomized controlled study was conducted in a hospital in China. The effect of intermittent hypoxia exposure (IHE; 5-min hypoxia alternating with 5-min normal air, repeated five times) on dyspnea and fatigue was investigated in patients meeting the NICE definition of PASC. Patients were computationally randomized to receive normoxia exposure (NE) and routine therapy or IHE and routine therapy. Six-minute walk distance (6MWD) and spirometry were tested before and after the interventions; the Borg Dyspnea Scale (Borg) and the modified Medical Research Council Dyspnea Scale (mMRC) were used to assess dyspnea; and the Fatigue Assessment Scale (FAS) and the Chalder Fatigue Scale-11 (CFQ-11) were used to assess fatigue. The study was registered in the Chinese Clinical Trial Registry (ChiCTR2300070565). FINDINGS Ninety-five participants (33 males and 62 females) were recruited between March 1, 2023 and December 30, 2023. Forty-seven patients in the IHE group received 10.0 (9.0, 15.0) days of IHE, and 48 patients in NE group received 10.0 (8.0, 12.0) days of NE. 6MWD, forced vital capacity (FVC), FVC %pred, forced expiratory volume in 1 s (FEV1), FEV1 %pred, tidal volume (VT), and dyspnea and fatigue scales markedly improved after IHE (p < 0.05), and improvements were greater than in the NE group (all p < 0.05). Furthermore, participants in IHE group had better subjective improvements in dyspnea and fatigue than those in the NE group (p < 0.05). Compared with <10 days of IHE, ≥10 days of IHE had a greater impact on 6MWD, FVC, FEV1, FEV1 %pred, VT, FAS, and CFQ-11. No severe adverse events were reported. INTERPRETATION IHE improved spirometry and 6MWD and relieved dyspnea and fatigue in PASC patients. Larger prospective studies are now needed to verify these findings.
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Affiliation(s)
- Shiqian Zha
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Xu Liu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Yan Yao
- Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Yang He
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Yixuan Wang
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Qingfeng Zhang
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Jingyi Zhang
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Yaohua Yi
- School of Remote Sensing and Information Engineering, Wuhan University, Wuhan, 430079, China; Research Center of Digital Imaging and Intelligent Perception, Wuhan University, Wuhan, 430079, China
| | - Rui Xiao
- School of Remote Sensing and Information Engineering, Wuhan University, Wuhan, 430079, China; Research Center of Digital Imaging and Intelligent Perception, Wuhan University, Wuhan, 430079, China
| | - Ke Hu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
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10
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Mateika JH, Barok R, Kissane DM. Is sustained hypercapnia required to initiate plasticity in humans exposed to mild intermittent hypoxia? J Physiol 2024; 602:5125-5128. [PMID: 39153224 DOI: 10.1113/jp287341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Accepted: 08/01/2024] [Indexed: 08/19/2024] Open
Affiliation(s)
- Jason H Mateika
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI, USA
| | - Rebecca Barok
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Dylan M Kissane
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
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11
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Burtscher J, Samaja M. Healthy Aging at Moderate Altitudes: Hypoxia and Hormesis. Gerontology 2024; 70:1152-1160. [PMID: 39348814 DOI: 10.1159/000541216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 08/27/2024] [Indexed: 10/02/2024] Open
Abstract
BACKGROUND Aging is associated with cellular and tissue responses that collectively lead to functional and structural deterioration of tissues. Poor tissue oxygenation, or hypoxia, is involved in such responses and contributes to aging. Consequently, it could be speculated that living at higher altitude, and therefore in hypoxic conditions, accelerates aging. This assumption is indeed supported by evidence from populations residing at very high altitudes (>3,500 m). In contrast, accumulating evidence suggests that living at moderate altitudes (1,500-2,500 m) is protective rather than injurious, at least for some body systems. SUMMARY In this review, we critically evaluate the hypothesis that the physiological responses to mild hypoxic stress associated to life at moderate altitudes provide protection from many hypoxia-related diseases through hormesis. Hormesis means that a low dose of a stressor (here hypoxia) elicits beneficial outcomes, while a higher dose can be toxic and might explain at least in part the dose-dependent contrasting effects of hypoxia on the aging processes. The lack of well-designed longitudinal studies focusing on the role of the altitude of residence, and difficulties in accounting for potentially confounding factors such as migration, ethnicity/genetics, and socioeconomic and geoclimatic conditions, currently hampers translation of related research into uncontroversial paradigms. KEY MESSAGES Deeper investigations are required to understand the impact of altitude-related hypoxia on age-related diseases and to develop molecular markers of ageing/senescence in humans that are linked to hypoxia. However, the presented emerging evidence supports the view that hypoxia conditioning has the potential to improve life quality and expectancy.
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Affiliation(s)
- Johannes Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Michele Samaja
- Department of Health Science, University of Milan, Milan, Italy
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12
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Smith CM, Salmon OF. Safety and effectiveness of acute intermittent hypoxia during a single treatment at different hypoxic severities. Respir Physiol Neurobiol 2024; 331:104358. [PMID: 39349270 DOI: 10.1016/j.resp.2024.104358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2024] [Revised: 09/24/2024] [Accepted: 09/25/2024] [Indexed: 10/02/2024]
Abstract
PURPOSE Examine the cardiovascular, muscular function, cognitive, and neural plastic responses to determine the safety and effectiveness of acute Intermittent hypoxia (AIH) at a low, high, and control fractional inspired oxygen (FiO2) dosage METHODS: Thirteen human participants performed 30-min of AIH in 60-s intervals at FiO2's of 0.21 (AIH21), 0.15 (AIH15), and 0.09 (AIH9). Heart rate variability (root mean squared of successive differences; RMSSD), heart rate, oxygen saturation (SpO2), blood pressure, muscular strength, neuromuscular activation, cerebral hemodynamic responses, cognition, symptomology, and brain-derived neurotrophic factor (BDNF) responses were measured before (Pre-AIH), after (post-AIH), and at 20-min of recovery (Recovery-AIH) RESULTS: There were no differences between AIH protocols for heart rate, RMSSD, blood pressure, or SpO2. Muscular strength improved Post-AIH for AIH15 (10 %) and AIH9 (14 %) and remained elevated (6 %) at Recovery-AIH. Neuromuscular activation increased Pre-AIH to Post-AIH for AIH15 (10 %) and AIH9 (11 %). Cerebral hemodynamic responses were not impacted between conditions. Both AIH15 and AIH9 increased BDNF Post-AIH (62 %) and Recovery-AIH (63 %) CONCLUSION: Acute intermittent hypoxia is generally safe and effective at producing neural plastic responses, but further examination of co-occurring cardiovascular diseases is needed. This study provides safety focused findings which will widen the adoption and refinement of AIH protocols.
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Affiliation(s)
- Cory M Smith
- Robbins College of Health and Human Sciences, Human & Environmental Physiology Laboratory, Baylor University, Waco, TX, USA.
| | - Owen F Salmon
- Robbins College of Health and Human Sciences, Human & Environmental Physiology Laboratory, Baylor University, Waco, TX, USA
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13
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董 梦, 朱 恬, 马 俊, 杜 晓, 冯 媛. [Reoxygenation improves reduced hypothalamic leptin responsiveness induced by intermittent hypoxia in obese rats]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2024; 44:1696-1703. [PMID: 39505337 PMCID: PMC11744080 DOI: 10.12122/j.issn.1673-4254.2024.09.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Indexed: 11/08/2024]
Abstract
OBJECTIVE To evaluate the effects of intermittent hypoxia-reoxygenation (IHR) on body weight, diet and water intake, circulating metabolites, and responses to central leptin injection in a rat model of diet-induced obesity (DIO). METHODS Rat models of DIO established by 12-week high-fat diet (HFD) feeding were randomized into normoxia group (n=15), intermittent hypoxia group (6% O2, 30 cycles/h, 8 h/day for 4 weeks; n=15), and IHR group (2 weeks of intermittent hypoxia followed by 2 weeks of reoxygenation; n=15). Body weight, diet and water intake of the rats were recorded, and circulating leptin, IL-6, and Ang-II levels were detected. After IHR treatment, the rats received intracerebroventricular injection of 4 μg leptin, and the hypothalamus and liver were taken 1 h later for detecting POMC, FRA-1 and FRA-2 expressions in the hypothalamus using immunohistochemistry, POMC, pSTAT3 and LepR expressions in the hypothalamus using Western blotting, and LepR mRNA expression in the hypothalamus and liver using RT-PCR. RESULTS The rats in intermittent hypoxia group showed significantly increased weight gain, food intake and elevated systemic inflammatory cytokine levels. Intermittent hypoxia obviously inhibited the expression of POMC, lowered the expressions of FRA-1 and pSTAT3, reduced the responsiveness of the rats to exogenous leptin, and downregulated the mRNA and protein expression of LepR. Two weeks of reoxygenation treatment obviously reduced intermittent hypoxia-induced weight gain and metabolic disorder and improved leptin sensitivity of the rats. CONCLUSION Prolonged intermittent hypoxia impairs hypothalamic leptin signaling by downregulating LepR expression to promote weight gain in obese rats, which can be improved by reoxygenation treatment.
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Affiliation(s)
- 梦璐 董
- 南方医科大学南方医院精神心理科(睡眠医学中心), 广东 广州 510515Department of Psychiatry (Sleep Medicine Center), School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
| | - 恬 朱
- 南方医科大学南方医院精神心理科(睡眠医学中心), 广东 广州 510515Department of Psychiatry (Sleep Medicine Center), School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
| | - 俊文 马
- 南方医科大学第一临床医学院, 广东 广州 510515First School of Clinical Medicine, Southern Medical University, Guangzhou 510515, China
| | - 晓红 杜
- 南昌大学第二附属医院麻醉科, 江西 南昌 330000Department of Anesthesiology, Second Affiliated Hospital of Nanchang University, Nanchang 330000, China
| | - 媛 冯
- 南方医科大学南方医院精神心理科(睡眠医学中心), 广东 广州 510515Department of Psychiatry (Sleep Medicine Center), School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
- 南方医科大学南方医院脑病研究院, 广东 广州 510515Institute of Brain Disease, Nanfang Hospital, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
- 南方医科大学基础医学院广东省蛋白质组学重点实验室, 广东 广州 510515Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
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14
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Sharma N, Khalyfa A, Cai D, Morales-Quinones M, Soares RN, Higashi Y, Chen S, Gozal D, Padilla J, Manrique-Acevedo C, Chandrasekar B, Martinez-Lemus LA. Chronic intermittent hypoxia facilitates the development of angiotensin II-induced abdominal aortic aneurysm in male mice. J Appl Physiol (1985) 2024; 137:527-539. [PMID: 38867666 PMCID: PMC11424178 DOI: 10.1152/japplphysiol.00842.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 04/11/2024] [Accepted: 06/05/2024] [Indexed: 06/14/2024] Open
Abstract
Obstructive sleep apnea (OSA), characterized by episodes of intermittent hypoxia (IH), is highly prevalent in patients with abdominal aortic aneurysm (AAA). However, whether IH serves as an independent risk factor for AAA development remains to be investigated. Here, we determined the effects of chronic (6 mo) IH on angiotensin (Ang II)-induced AAA development in C57BL/6J male mice and investigated the underlying mechanisms of IH in cultured vascular smooth muscle cells (SMCs). IH increased the susceptibility of mice to develop AAA in response to Ang II infusion by facilitating the augmentation of the abdominal aorta's diameter as assessed by transabdominal ultrasound imaging. Importantly, IH with Ang II augmented aortic elastin degradation and the expression of matrix metalloproteinases (MMPs), mainly MMP8, MMP12, and a disintegrin and metalloproteinase-17 (ADAM17) as measured by histology and immunohistochemistry. Mechanistically, IH increased the activities of MMP2, MMP8, MMP9, MMP12, and ADAM17, while reducing the expression of the MMP regulator reversion-inducing cysteine-rich protein with Kazal motifs (RECK) in cultured SMCs. Aortic samples from human AAA were associated with decreased RECK and increased expression of ADAM17 and MMPs. These data suggest that IH facilitates AAA development when additional stressors are superimposed and that this occurs in association with an increased presence of aortic MMPs and ADAM17, potentially due to IH-induced modulation of RECK expression. These findings support a plausible synergistic link between OSA and AAA and provide a better understanding of the molecular mechanisms underlying the pathogenesis of AAA.NEW & NOTEWORTHY IH facilitates Ang II-induced abdominal aortic diameter expansion and AAA development in C57BL/6J male mice. IH upregulates the expression of specific MMPs such as MMP8, MMP12, and ADAM17. IH directly suppresses RECK expression and increases MMPs activity in SMCs. Human AAA tissues exhibit a downregulation of RECK and an upregulation of ADAM17 and MMPs.
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MESH Headings
- Aortic Aneurysm, Abdominal/metabolism
- Aortic Aneurysm, Abdominal/chemically induced
- Aortic Aneurysm, Abdominal/pathology
- Animals
- Male
- Angiotensin II
- Mice, Inbred C57BL
- Hypoxia/metabolism
- Hypoxia/complications
- Mice
- ADAM17 Protein/metabolism
- Aorta, Abdominal/metabolism
- Aorta, Abdominal/pathology
- Myocytes, Smooth Muscle/metabolism
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Humans
- Matrix Metalloproteinases/metabolism
- Matrix Metalloproteinase 12/metabolism
- Sleep Apnea, Obstructive/metabolism
- Sleep Apnea, Obstructive/physiopathology
- Sleep Apnea, Obstructive/complications
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Affiliation(s)
- Neekun Sharma
- NextGen Precision Health, University of Missouri, Columbia, Missouri, United States
- Department of Medicine, Center for Precision Medicine, University of Missouri, Columbia, Missouri, United States
- Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Abdelnaby Khalyfa
- Department of Child Health and the Child Health Research Institute, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Dunpeng Cai
- Department of Surgery, University of Missouri, Columbia, Missouri, United States
| | | | - Rogerio N Soares
- NextGen Precision Health, University of Missouri, Columbia, Missouri, United States
| | - Yusuke Higashi
- John W. Deming Department of Medicine, Tulane University, New Orleans, Louisiana, United States
| | - Shiyou Chen
- Department of Surgery, University of Missouri, Columbia, Missouri, United States
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, United States
| | - David Gozal
- Department of Child Health and the Child Health Research Institute, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Jaume Padilla
- NextGen Precision Health, University of Missouri, Columbia, Missouri, United States
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
| | - Camila Manrique-Acevedo
- NextGen Precision Health, University of Missouri, Columbia, Missouri, United States
- Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri, Columbia, Missouri, United States
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, United States
| | - Bysani Chandrasekar
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, United States
- Division of Cadiovascular Medicine, Department of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Luis A Martinez-Lemus
- NextGen Precision Health, University of Missouri, Columbia, Missouri, United States
- Department of Medicine, Center for Precision Medicine, University of Missouri, Columbia, Missouri, United States
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, United States
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15
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Zha S, Liu X, Chen H, Hao Y, Zhang J, Zhang Q, Hu K. Combination of acute intermittent hypoxia and intermittent transcutaneous electrical stimulation in obstructive sleep apnea: a randomized controlled crossover trial. Respir Physiol Neurobiol 2024; 327:104298. [PMID: 38885891 DOI: 10.1016/j.resp.2024.104298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/04/2024] [Accepted: 06/10/2024] [Indexed: 06/20/2024]
Abstract
Intermittent hypoxia (IH) and intermittent transcutaneous electrical stimulation (ITES) might benefit patients with obstructive sleep apnea (OSA). However, the therapeutic value of combined IH and ITES in OSA is unknown. In this prospective, randomized, controlled crossover study, normoxia (air exposure for 50 min before sleep and sham stimulation for 6 h during sleep), IH (5 repeats of 5 min 10-12 % O2 alternating with 5 min air for 50 min, and sham stimulation for 6 h), ITES (air exposure for 50 min and 6 repeats of 30 min transcutaneous electrical stimulation alternating with 30 min of sham stimulation for 6 h), and IH&ITES (10-12 % O2 alternating with air for 50 min and transcutaneous electrical stimulation alternating with sham stimulation for 6 h) were administered to patients with OSA over four single-night sessions. The primary endpoint was difference in OSA severity between the interventions according to apnea-hypopnea index (AHI) and oxygen desaturation index (ODI). The efficacy was response to IH, ITES, IH&ITES defined as a ≥50 % reduction in AHI compared with normoxia. Twenty participants (17 male, 3 female) completed the trial. The median (IQR) AHI decreased from 14.5 (10.8, 17.5) events/h with normoxia to 6.9 (3.9, 14.8) events/h with IH (p=0.020), 5.7 (3.4, 9.1) events/h with ITES (p=0.001), and 3.5 (1.8, 6.4) events/h with IH&ITES (p=0.001). AHI was significantly different between IH and IH&ITES (p=0.042) but not between ITES and IH&ITES (p=0.850). For mild-moderate OSA (n=17), IH, ITES, and IH&ITES had a significant effect on AHI (p=0.013, p=0.001, p=0.001, respectively) compared with normoxia, but there were no differences in post hoc pairwise comparisons between intervention groups. No serious adverse events were observed. In conclusion, IH, ITES, and IH&ITES significantly reduced OSA severity. IH&ITES showed better efficacy in mild-moderate OSA than IH and was comparable to ITES. Our data do not support recommending IH&ITES over ITES for OSA.
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Affiliation(s)
- Shiqian Zha
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Xu Liu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Hao Chen
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Yueying Hao
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Jingyi Zhang
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Qingfeng Zhang
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Ke Hu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan 430060, China.
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16
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Welch JF, Vose AK, Cavka K, Brunetti G, DeMark LA, Snyder H, Wauneka CN, Tonuzi G, Nair J, Mitchell GS, Fox EJ. Cardiorespiratory Responses to Acute Intermittent Hypoxia in Humans With Chronic Spinal Cord Injury. J Neurotrauma 2024; 41:2114-2124. [PMID: 38468543 PMCID: PMC12056581 DOI: 10.1089/neu.2023.0353] [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] [Indexed: 03/13/2024] Open
Abstract
Brief exposure to repeated episodes of low inspired oxygen, or acute intermittent hypoxia (AIH), is a promising therapeutic modality to improve motor function after chronic, incomplete spinal cord injury (SCI). Although therapeutic AIH is under extensive investigation in persons with SCI, limited data are available concerning cardiorespiratory responses during and after AIH exposure despite implications for AIH safety and tolerability. Thus, we recorded immediate (during treatment) and enduring (up to 30 min post-treatment) cardiorespiratory responses to AIH in 19 participants with chronic SCI (>1 year post-injury; injury levels C1 to T6; American Spinal Injury Association Impairment Scale A to D; mean age = 33.8 ± 14.1 years; 18 males). Participants completed a single AIH (15, 60-sec episodes, inspired O2 ≈ 10%; 90-sec intervals breathing room air) and Sham (inspired O2 ≈ 21%) treatment, in random order. During hypoxic episodes: (1) arterial oxyhemoglobin saturation decreased to 82.1 ± 2.9% (p < 0.001); (2) minute ventilation increased 3.83 ± 2.29 L/min (p = 0.008); and (3) heart rate increased 4.77 ± 6.82 bpm (p = 0.010). Considerable variability in cardiorespiratory responses was found among subjects; some individuals exhibited large hypoxic ventilatory responses (≥0.20 L/min/%, n = 11), whereas others responded minimally (<0.20 L/min/%, n = 8). Apneas occurred frequently during AIH and/or Sham protocols in multiple participants. All participants completed AIH treatment without difficulty. No significant changes in ventilation, heart rate, or arterial blood pressure were found 30 min post-AIH p > 0.05). In conclusion, therapeutic AIH is well tolerated, elicits variable chemoreflex activation, and does not cause persistent changes in cardiorespiratory control/function 30 min post-treatment in persons with chronic SCI.
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Affiliation(s)
- Joseph F. Welch
- Breathing Research and Therapeutics Center and Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
- McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Alicia K. Vose
- Breathing Research and Therapeutics Center and Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
- McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
- Brooks Rehabilitation, Jacksonville, Florida, USA
- Department of Neurology, College of Medicine–Jacksonville, University of Florida, Jacksonville, Florida, USA
| | - Kate Cavka
- Brooks Rehabilitation, Jacksonville, Florida, USA
| | | | | | | | | | | | - Jayakrishnan Nair
- Breathing Research and Therapeutics Center and Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
- McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
- Department of Physical Therapy, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Gordon S. Mitchell
- Breathing Research and Therapeutics Center and Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
- McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Emily J. Fox
- Breathing Research and Therapeutics Center and Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
- Brooks Rehabilitation, Jacksonville, Florida, USA
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17
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Zha S, Liu X, Chen H, Hao Y, Zhang J, Zhang Q, Hu K. A randomized controlled crossover trial of acute intermittent and continuous hypoxia exposure in mild-moderate obstructive sleep apnea: A feasibility study. J Sleep Res 2024; 33:e14014. [PMID: 37592825 DOI: 10.1111/jsr.14014] [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: 03/08/2023] [Revised: 06/21/2023] [Accepted: 07/25/2023] [Indexed: 08/19/2023]
Abstract
In a prospective, randomized, controlled crossover study, we explored the effects of acute intermittent hypoxia and acute continuous hypoxia on patients with mild-moderate obstructive sleep apnea. Over three single-night sessions, subjects were alternately exposed to normoxia, acute continuous hypoxia and acute intermittent hypoxia before sleep. The apnea-hypopnea index and oxygen desaturation index were used to diagnose obstructive sleep apnea and evaluate efficacy. A responder was defined as a participant with a ≥ 50% reduction in apnea-hypopnea index between normoxia and hypoxia exposure. Sixteen participants with mild-moderate obstructive sleep apnea completed the study. Compared with normoxia, the mean apnea-hypopnea index decreased by 8.9 events per hr (95% confidence interval, 4.2-13.6, p = 0.001) with acute intermittent hypoxia and by 4.1 events per hr (95% confidence interval, 0.5-8.8, p = 0.082) with acute continuous hypoxia, equating to a mean decrease in apnea-hypopnea index of 4.8 events per hr (95% confidence interval, 0.1-9.5, p = 0.046) with acute intermittent hypoxia compared with acute continuous hypoxia. Compared with normoxia, the mean oxygen desaturation index decreased by 9.8 events per hr (95% confidence interval, 4.4-15.1, p = 0.001) with acute intermittent hypoxia but did not significantly decrease with acute continuous hypoxia; the mean oxygen desaturation index decreased by 7.2 events per hr (95% confidence interval, 1.8-12.6, p = 0.010) with acute intermittent hypoxia compared with acute continuous hypoxia. Of the 16 participants, 11 responded to acute intermittent hypoxia and four responded to acute continuous hypoxia (p = 0.032), of whom eight of 11 cases and all four cases had oxygen desaturation indexes <5 events per hr, respectively (p = 0.273). All participants tolerated acute intermittent hypoxia and there were no obvious adverse events during acute intermittent hypoxia exposure. In conclusion, acute intermittent hypoxia exposure improved apnea-hypopnea index and oxygen desaturation index in patients with mild-moderate obstructive sleep apnea, suggesting that further prospective validation of intermittent hypoxia exposure in patients with obstructive sleep apnea is needed to establish its clinical feasibility as a therapeutic modality.
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Affiliation(s)
- Shiqian Zha
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xu Liu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Hao Chen
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yueying Hao
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Jingyi Zhang
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Qingfeng Zhang
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, China
| | - Ke Hu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, China
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18
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Burtscher J, Raberin A, Brocherie F, Malatesta D, Manferdelli G, Citherlet T, Krumm B, Bourdillon N, Antero J, Rasica L, Burtscher M, Millet GP. Recommendations for Women in Mountain Sports and Hypoxia Training/Conditioning. Sports Med 2024; 54:795-811. [PMID: 38082199 PMCID: PMC11052836 DOI: 10.1007/s40279-023-01970-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2023] [Indexed: 04/28/2024]
Abstract
The (patho-)physiological responses to hypoxia are highly heterogeneous between individuals. In this review, we focused on the roles of sex differences, which emerge as important factors in the regulation of the body's reaction to hypoxia. Several aspects should be considered for future research on hypoxia-related sex differences, particularly altitude training and clinical applications of hypoxia, as these will affect the selection of the optimal dose regarding safety and efficiency. There are several implications, but there are no practical recommendations if/how women should behave differently from men to optimise the benefits or minimise the risks of these hypoxia-related practices. Here, we evaluate the scarce scientific evidence of distinct (patho)physiological responses and adaptations to high altitude/hypoxia, biomechanical/anatomical differences in uphill/downhill locomotion, which is highly relevant for exercising in mountainous environments, and potentially differential effects of altitude training in women. Based on these factors, we derive sex-specific recommendations for mountain sports and intermittent hypoxia conditioning: (1) Although higher vulnerabilities of women to acute mountain sickness have not been unambiguously shown, sex-dependent physiological reactions to hypoxia may contribute to an increased acute mountain sickness vulnerability in some women. Adequate acclimatisation, slow ascent speed and/or preventive medication (e.g. acetazolamide) are solutions. (2) Targeted training of the respiratory musculature could be a valuable preparation for altitude training in women. (3) Sex hormones influence hypoxia responses and hormonal-cycle and/or menstrual-cycle phases therefore may be factors in acclimatisation to altitude and efficiency of altitude training. As many of the recommendations or observations of the present work remain partly speculative, we join previous calls for further quality research on female athletes in sports to be extended to the field of altitude and hypoxia.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Antoine Raberin
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport, Paris, France
| | - Davide Malatesta
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Giorgio Manferdelli
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Tom Citherlet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Bastien Krumm
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Nicolas Bourdillon
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland
| | - Juliana Antero
- Institut de Recherche Bio-Médicale Et d'Épidémiologie du Sport (EA 7329), French Institute of Sport, Paris, France
| | - Letizia Rasica
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Building Synathlon, Campus Dorigny, 1015, Lausanne, Switzerland.
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19
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Zhang Y, Pan YD, Zheng WY, Li HY, Zhu MZ, Ou Yang WJ, Qian Y, Turecki G, Mechawar N, Zhu XH. Enhancing HIF-1α-P2X2 signaling in dorsal raphe serotonergic neurons promotes psychological resilience. Redox Biol 2024; 69:103005. [PMID: 38150991 PMCID: PMC10788260 DOI: 10.1016/j.redox.2023.103005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 12/17/2023] [Indexed: 12/29/2023] Open
Abstract
Major depressive disorder (MDD) is a devastating condition. Although progress has been made in the past seven decades, patients with MDD continue to receive an inadequate treatment, primarily due to the late onset of first-line antidepressant drugs and to their acute withdrawal symptoms. Resilience is the ability to rebound from adversity in a healthy manner and many people have psychological resilience. Revealing the mechanisms and identifying methods promoting resilience will hopefully lead to more effective prevention strategies and treatments for depression. In this study, we found that intermittent hypobaric hypoxia training (IHHT), a method for training pilots and mountaineers, enhanced psychological resilience in adult mice. IHHT produced a sustained antidepressant-like effect in mouse models of depression by inducing long-term (up to 3 months after this treatment) overexpression of hypoxia-inducible factor (HIF)-1α in the dorsal raphe nucleus (DRN) of adult mice. Moreover, DRN-infusion of cobalt chloride, which mimics hypoxia increasing HIF-1α expression, triggered a rapid and long-lasting antidepressant-like effect. Down-regulation of HIF-1α in the DRN serotonergic (DRN5-HT) neurons attenuated the effects of IHHT. HIF-1α translationally regulated the expression of P2X2, and conditionally knocking out P2rx2 (encodes P2X2 receptors) in DRN5-HT neurons, in turn, attenuated the sustained antidepressant-like effect of IHHT, but not its acute effect. In line with these results, a single sub-anesthetic dose of ketamine enhanced HIF-1α-P2X2 signaling, which is essential for its rapid and long-lasting antidepressant-like effect. Notably, we found that P2X2 protein levels were significantly lower in the DRN of patients with MDD than that of control subjects. Together, these findings elucidate the molecular mechanism underlying IHHT promoting psychological resilience and highlight enhancing HIF-1α-P2X2 signaling in DRN5-HT neurons as a potential avenue for screening novel therapeutic treatments for MDD.
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Affiliation(s)
- Yuan Zhang
- School of Psychology, Shenzhen University, Shenzhen, China; Research Center for Brain Health, Pazhou Lab, Guangzhou, China
| | - Yi-da Pan
- Research Center for Brain Health, Pazhou Lab, Guangzhou, China
| | - Wen-Ying Zheng
- School of Psychology, Shenzhen University, Shenzhen, China; Research Center for Brain Health, Pazhou Lab, Guangzhou, China
| | - Huan-Yu Li
- Research Center for Brain Health, Pazhou Lab, Guangzhou, China
| | - Min-Zhen Zhu
- Research Center for Brain Health, Pazhou Lab, Guangzhou, China
| | - Wen-Jie Ou Yang
- School of Psychology, Shenzhen University, Shenzhen, China; Research Center for Brain Health, Pazhou Lab, Guangzhou, China
| | - Yu Qian
- Research Center for Brain Health, Pazhou Lab, Guangzhou, China; School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Gustavo Turecki
- Department of Psychiatry, McGill University, McGill Group for Suicide Studies, Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, (Québec), Canada
| | - Naguib Mechawar
- Department of Psychiatry, McGill University, McGill Group for Suicide Studies, Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, (Québec), Canada
| | - Xin-Hong Zhu
- School of Psychology, Shenzhen University, Shenzhen, China; Research Center for Brain Health, Pazhou Lab, Guangzhou, China; School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.
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20
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Puri S, Panza GS, Kissane D, Jones S, Reck K, Lin HS, Badr MS, Mateika JH. Racial differences in upper airway collapsibility and loop gain in young adult males. Sleep 2023; 46:zsad091. [PMID: 36999953 PMCID: PMC10710980 DOI: 10.1093/sleep/zsad091] [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: 02/24/2023] [Revised: 03/16/2023] [Indexed: 04/01/2023] Open
Abstract
STUDY OBJECTIVES Previous studies reported that the apnea-hypopnea index was similar in young adult Black and White participants. However, whether this similarity reflects an analogous combination of apneas and hypopneas is unknown. Likewise, the physiological mechanisms underlying this similarity has not been explored. METHODS 60 Black and 48 White males completed the study. After matching for age and body mass index, 41 participants remained in each group. All participants completed a sleep study. Subsequently, standard sleep indices along with loop gain and the arousal threshold were determined. In addition, airway collapsibility (24 of 60 and 14 of 48 participants) and the hypoxic ventilatory response during wakefulness (30 of 60 and 25 of 48 participants) was measured. RESULTS The apnea-hypopnea index was similar in Blacks and Whites (p = .140). However, the index was comprised of more apneas (p = .014) and fewer hypopneas (p = .025) in Black males. These modifications were coupled to a reduced loop gain (p = .0002) and a more collapsible airway (p = .030). These differences were independent of whether or not the groups were matched. For a given hypoxic response, loop gain was reduced in Black compared to White males (p = .023). CONCLUSIONS Despite a similar apnea-hypopnea index, more apneas and fewer hypopneas were evident in young adult Black compared to White males. The physiological mechanisms that contribute to these events were also different between groups. Addressing these differences may be important when considering novel therapeutic approaches to eliminate apnea in Black and White participants.
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Affiliation(s)
- Shipra Puri
- Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Gino S Panza
- Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA
- Department of Health Care Sciences, College of Pharmacy and Health Science, Detroit, MI 48201, USA
| | - Dylan Kissane
- Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Steven Jones
- Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Kevin Reck
- Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Ho-Sheng Lin
- Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA
- Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - M Safwan Badr
- Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
- Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Jason H Mateika
- Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
- Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI 48201, USA
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21
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Bonsignore MR. Adaptive responses to chronic intermittent hypoxia: contributions from the European Sleep Apnoea Database (ESADA) Cohort. J Physiol 2023; 601:5467-5480. [PMID: 37218069 DOI: 10.1113/jp284108] [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: 02/01/2023] [Accepted: 05/18/2023] [Indexed: 05/24/2023] Open
Abstract
Obstructive sleep apnoea (OSA) is a common disease in the general population, and is associated with increased cardiovascular risk and several comorbidities. Obesity favours upper airway collapsibility, but other pathophysiological traits have been identified, i.e. upper airway muscle activity, modulation of the respiratory drive, and the arousal threshold. OSA causes chronic intermittent hypoxia, inflammatory activation and autonomic imbalance with diurnal and nocturnal sympathetic hyperactivity. Disentangling so many components to investigate the pathogenesis of OSA's consequences is very hard clinically. However, albeit imperfect, clinical medicine constitutes a major source of inspiration for basic research, and a mutual exchange of information is essential between clinicians and physiologists to improve our understanding of disease states. OSA is no exception, and this narrative review will summarize the results of clinical studies performed over the years by the European Sleep Apnoea Database (ESADA) Study Group, to explore the variables linked to markers of intermittent hypoxia as opposed to the traditional assessment of OSA severity based on the frequency of respiratory events during sleep (the Apnoea Hypopnoea Index). The results of the clinical studies indicate that intermittent hypoxia variables are associated with several comorbidities, although evidence of a cause-effect relationship is still missing in many cases. It is also possible that adaptive rather than maladaptive responses could be evoked by intermittent hypoxia. The intensity, duration and frequency of intermittent hypoxia episodes causing adaptive rather than maladaptive responses, and their clinical implications, deserve further investigation.
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Affiliation(s)
- Maria R Bonsignore
- PROMISE Department, University of Palermo, Palermo, Italy
- Sleep Disordered Breathing Clinic, Division of Pneumology, V. Cervello Hospital, Palermo, Italy
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22
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Esmaeili N, Labarca G, Hu WH, Vena D, Messineo L, Gell L, Hajipour M, Taranto-Montemurro L, Sands SA, Redline S, Wellman A, Sehhati M, Azarbarzin A. Hypoxic Burden Based on Automatically Identified Desaturations Is Associated with Adverse Health Outcomes. Ann Am Thorac Soc 2023; 20:1633-1641. [PMID: 37531573 PMCID: PMC10632930 DOI: 10.1513/annalsats.202303-248oc] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 08/02/2023] [Indexed: 08/04/2023] Open
Abstract
Rationale: Recent studies have shown that sleep apnea-specific intermittent hypoxemia quantified by the hypoxic burden (HB) predicted cardiovascular disease (CVD)-related mortality in community-based and clinical cohorts. Calculation of HB is based on manual scoring of hypopneas and apneas, which is time-consuming and prone to interscorer variability. Objective: To validate a novel method to quantify the HB that is based on automatically scored desaturations. Methods: The sample included 5,655 middle-aged or older adults from the Sleep Heart Health Study (52.8% women; age, 63.2 ± 11.3 yr). The original HB method was based on a subject-specific search window obtained from an ensemble average of oxygen saturation signals (as measured by pulse oximetry) and synchronized with respect to the termination of scored respiratory events. In this study, however, the search window was obtained from ensemble average of oxygen saturation signals that synchronized with respect to the minimum of all automatically identified desaturations (⩾2% and other thresholds, including 3% and 4%, in sensitivity analyses). The time interval between the two maxima around the minimum saturation was defined as the search window. The oximetry-derived HB (HBOxi) was defined as the total area under all desaturation curves (restricted by the search window) divided by the total sleep time. Logistic and Cox regression models assessed the adjusted odds ratio (aOR)/hazard ratio of excessive daytime sleepiness (EDS), hypertension (HTN), and CVD mortality per 1-standard deviation increase in HBOxi after adjusting for several covariates and confounders. Results: The Spearman's rank correlation between HB (median [interquartile range], 34.4 [18.4-59.8] % min/h) and HBOxi (median [interquartile range], 34.5 [21.6-53.8] % min/h) was 0.81 (P < 0.001). Similar to HB, HBOxi was significantly associated with EDS (aOR [95% confidence interval (CI)], 1.17 [1.09-1.26] per standard deviation), HTN (aOR [95% CI], 1.13 [1.05-1.21]), and CVD mortality (adjusted hazard ratio [95% CI], 1.15 [1.01-1.30]) in fully adjusted models. Conclusions: The HBOxi was highly correlated with the HB based on manually scored apneas and hypopneas and was associated with EDS, HTN, and CVD mortality with similar effect sizes as previously reported. This method could be incorporated into wearable technology that accurately records oxygen saturation signals.
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Affiliation(s)
- Neda Esmaeili
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Bioelectric and Biomedical Engineering, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; and
| | - Gonzalo Labarca
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Wen-Hsin Hu
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Daniel Vena
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ludovico Messineo
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Laura Gell
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Mohammadreza Hajipour
- Department of Experimental Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Luigi Taranto-Montemurro
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Scott A. Sands
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Susan Redline
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Mohammadreza Sehhati
- Department of Bioelectric and Biomedical Engineering, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; and
| | - Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
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23
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Panza GS, Burtscher J, Zhao F. Intermittent hypoxia: a call for harmonization in terminology. J Appl Physiol (1985) 2023; 135:886-890. [PMID: 37560767 PMCID: PMC10642510 DOI: 10.1152/japplphysiol.00458.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/24/2023] [Accepted: 08/03/2023] [Indexed: 08/11/2023] Open
Abstract
Mild intermittent hypoxia may be a potent novel strategy to improve cardiovascular function, motor and cognitive function, and altitude acclimatization. However, there is still a stigma surrounding the field of intermittent hypoxia (IH). Major contributors to this stigma may be due to the overlapping terminology, heterogeneous methodological approaches, and an almost dogmatic focus on different mechanistic underpinnings in different fields of research. Many clinicians and investigators explore the pathophysiological outcomes following long-term exposure to IH in an attempt to improve our understanding of sleep apnea (SA) and develop new treatment plans. However, others use IH as a tool to improve physiological outcomes such as blood pressure, motor function, and altitude acclimatization. Unfortunately, studies investigating the pathophysiology of SA or the potential benefit of IH use similar, unstandardized terminologies facilitating a confusion surrounding IH protocols and the intentions of various studies. In this perspective paper, we aim to highlight IH terminology-related issues with the aim of spurring harmonization of the terminology used in the field of IH research to account for distinct outcomes of hypoxia exposure depending on protocol and individuum.
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Affiliation(s)
- Gino S Panza
- Department of Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan, United States
- Department of Health Care Sciences, Program of Occupational Therapy, Wayne State University, Detroit, Michigan, United States
| | - Johannes Burtscher
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Fei Zhao
- Department of Research and Development, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan, United States
- Department of Health Care Sciences, Program of Occupational Therapy, Wayne State University, Detroit, Michigan, United States
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24
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Panza GS, Kissane DM, Puri S, Mateika JH. The hypoxic ventilatory response and hypoxic burden are predictors of the magnitude of ventilatory long-term facilitation in humans. J Physiol 2023; 601:4611-4623. [PMID: 37641466 PMCID: PMC11006398 DOI: 10.1113/jp285192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 08/16/2023] [Indexed: 08/31/2023] Open
Abstract
Mild intermittent hypoxia initiates progressive augmentation (PA) and ventilatory long-term facilitation (vLTF) in humans. The magnitude of these forms of plasticity might be influenced by anthropometric and physiological variables, as well as protocol elements. However, the impact of many of these variables on the magnitude of respiratory plasticity has not been established in humans. A meta-analysis was completed using anthropometric and physiological variables obtained from 124 participants that completed one of three intermittent hypoxia protocols. Simple correlations between the aggregate variables and the magnitude of PA and vLTF standardized to baseline was completed. Thereafter, the variables correlated to PA or vLTF were input into a multilinear regression equation. Baseline measures of the hypoxic ventilatory response was the sole predictor of PA (R = 0.370, P = 0.012). Similarly, this variable along with the hypoxic burden predicted the magnitude of vLTF (R = 0.546, P < 0.006 for both variables). In addition, the magnitude of PA was strongly correlated to vLTF (R = 0.617, P < 0.001). Anthropometric measures do not predict the magnitude of PA and vLTF in humans. Alternatively, the hypoxic ventilatory response was the sole predictor of PA, and in combination with the hypoxic burden, predicted the magnitude of vLTF. These influences should be considered in the design of mild intermittent hypoxia protocol studies in humans. Moreover, the strong correlation between PA and vLTF suggests that a common mechanistic pathway may have a role in the initiation of these forms of plasticity. KEY POINTS: Mild intermittent hypoxia initiates progressive augmentation (PA) and ventilatory long-term facilitation (vLTF) in humans. Many of the anthropometric and physiological variables that could impact the magnitude of these forms of plasticity are unknown. Anthropometric and physiological variables were measured from a total of 124 participants that completed one of three distinct intermittent hypoxia protocols. The variables correlated to PA or vLTF were input into a multilinear regression analysis. The hypoxic ventilatory response was the sole predictor of PA, while this variable in addition to the average hypoxic burden predicted the magnitude of vLTF. A strong correlation between PA and vLTF was also revealed. These influences should be considered in the design of mild intermittent hypoxia protocol studies in humans. Moreover, the strong correlation between PA and vLTF suggests that a common mechanistic pathway may have a role in the initiation of these forms of plasticity.
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Affiliation(s)
- Gino S Panza
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
- Department of Health Care Sciences, Program of Occupational Therapy, Wayne State University, Detroit, MI, USA
| | - Dylan M Kissane
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Shipra Puri
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Jason H Mateika
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, USA
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI, USA
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25
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Zhang Q, Zhao W, Li S, Ding Y, Wang Y, Ji X. Intermittent Hypoxia Conditioning: A Potential Multi-Organ Protective Therapeutic Strategy. Int J Med Sci 2023; 20:1551-1561. [PMID: 37859700 PMCID: PMC10583178 DOI: 10.7150/ijms.86622] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/08/2023] [Indexed: 10/21/2023] Open
Abstract
Severe hypoxia can induce a range of systemic disorders; however, surprising resilience can be obtained through sublethal adaptation to hypoxia, a process termed as hypoxic conditioning. A particular form of this strategy, known as intermittent hypoxia conditioning hormesis, alternates exposure to hypoxic and normoxic conditions, facilitating adaptation to reduced oxygen availability. This technique, originally employed in sports and high-altitude medicine, has shown promise in multiple pathologies when applied with calibrated mild to moderate hypoxia and appropriate hypoxic cycles. Recent studies have extensively investigated the protective role of intermittent hypoxia conditioning and its underlying mechanisms using animal models, demonstrating its potential in organ protection. This involves a range of processes such as reduction of oxidative stress, inflammation, and apoptosis, along with enhancement of hypoxic gene expression, among others. Given that intermittent hypoxia conditioning fosters beneficial physiological responses across multiple organs and systems, this review presents a comprehensive analysis of existing studies on intermittent hypoxia and its potential advantages in various organs. It aims to draw attention to the possibility of clinically applying intermittent hypoxia conditioning as a multi-organ protective strategy. This review comprehensively discusses the protective effects of intermittent hypoxia across multiple systems, outlines potential procedures for implementing intermittent hypoxia, and provides a brief overview of the potential protective mechanisms of intermittent hypoxia.
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Affiliation(s)
- Qihan Zhang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Wenbo Zhao
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Sijie Li
- Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
- Emergency Department, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yuchuan Ding
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Yuan Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xunming Ji
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
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26
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Burtscher J, Hohenauer E, Burtscher M, Millet GP, Egg M. Environmental and behavioral regulation of HIF-mitochondria crosstalk. Free Radic Biol Med 2023; 206:63-73. [PMID: 37385566 DOI: 10.1016/j.freeradbiomed.2023.06.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/05/2023] [Accepted: 06/19/2023] [Indexed: 07/01/2023]
Abstract
Reduced oxygen availability (hypoxia) can lead to cell and organ damage. Therefore, aerobic species depend on efficient mechanisms to counteract detrimental consequences of hypoxia. Hypoxia inducible factors (HIFs) and mitochondria are integral components of the cellular response to hypoxia and coordinate both distinct and highly intertwined adaptations. This leads to reduced dependence on oxygen, improved oxygen supply, maintained energy provision by metabolic remodeling and tapping into alternative pathways and increased resilience to hypoxic injuries. On one hand, many pathologies are associated with hypoxia and hypoxia can drive disease progression, for example in many cancer and neurological diseases. But on the other hand, controlled induction of hypoxia responses via HIFs and mitochondria can elicit profound health benefits and increase resilience. To tackle pathological hypoxia conditions or to apply health-promoting hypoxia exposures efficiently, cellular and systemic responses to hypoxia need to be well understood. Here we first summarize the well-established link between HIFs and mitochondria in orchestrating hypoxia-induced adaptations and then outline major environmental and behavioral modulators of their interaction that remain poorly understood.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
| | - Erich Hohenauer
- Rehabilitation and Exercise Science Laboratory (RES Lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland; International University of Applied Sciences THIM, Landquart, Switzerland; Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland; Department of Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Margit Egg
- Institute of Zoology, University of Innsbruck, Innsbruck, Austria
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27
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Bock JM, Greenlund IM, Somers VK, Baker SE. Sex Differences in Neurovascular Control: Implications for Obstructive Sleep Apnea. Int J Mol Sci 2023; 24:13094. [PMID: 37685900 PMCID: PMC10487948 DOI: 10.3390/ijms241713094] [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: 07/11/2023] [Revised: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 09/10/2023] Open
Abstract
Patients with obstructive sleep apnea (OSA) have a heightened risk of developing cardiovascular diseases, namely hypertension. While seminal evidence indicates a causal role for sympathetic nerve activity in the hypertensive phenotype commonly observed in patients with OSA, no studies have investigated potential sex differences in the sympathetic regulation of blood pressure in this population. Supporting this exploration are large-scale observational data, as well as controlled interventional studies in healthy adults, indicating that sleep disruption increases blood pressure to a greater extent in females relative to males. Furthermore, females with severe OSA demonstrate a more pronounced hypoxic burden (i.e., disease severity) during rapid eye movement sleep when sympathetic nerve activity is greatest. These findings would suggest that females are at greater risk for the hemodynamic consequences of OSA and related sleep disruption. Accordingly, the purpose of this review is three-fold: (1) to review the literature linking sympathetic nerve activity to hypertension in OSA, (2) to highlight recent experimental data supporting the hypothesis of sex differences in the regulation of sympathetic nerve activity in OSA, and (3) to discuss the potential sex differences in peripheral adrenergic signaling that may contribute to, or offset, cardiovascular risk in patients with OSA.
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Affiliation(s)
- Joshua M. Bock
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA; (J.M.B.)
| | - Ian M. Greenlund
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA; (J.M.B.)
| | - Virend K. Somers
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA; (J.M.B.)
| | - Sarah E. Baker
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN 55901, USA
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28
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Redline S, Azarbarzin A, Peker Y. Obstructive sleep apnoea heterogeneity and cardiovascular disease. Nat Rev Cardiol 2023; 20:560-573. [PMID: 36899115 DOI: 10.1038/s41569-023-00846-6] [Citation(s) in RCA: 118] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/02/2023] [Indexed: 03/12/2023]
Abstract
Obstructive sleep apnoea (OSA), characterized by recurrent periods of upper airway obstruction and intermittent hypoxaemia, is prevalent in patients with cardiovascular disease (CVD), and is therefore important to consider in the prevention and management of CVD. Observational studies indicate that OSA is a risk factor for incident hypertension, poorly controlled blood pressure, stroke, myocardial infarction, heart failure, cardiac arrhythmias, sudden cardiac death and all-cause death. However, clinical trials have not provided consistent evidence that treatment with continuous positive airway pressure (CPAP) improves cardiovascular outcomes. These overall null findings might be explained by limitations in trial design and low levels of adherence to CPAP. Studies have also been limited by the failure to consider OSA as a heterogeneous disorder that consists of multiple subtypes resulting from variable contributions from anatomical, physiological, inflammatory and obesity-related risk factors, and resulting in different physiological disturbances. Novel markers of sleep apnoea-associated hypoxic burden and cardiac autonomic response have emerged as predictors of OSA-related susceptibility to adverse health outcomes and treatment response. In this Review, we summarize our understanding of the shared risk factors and causal links between OSA and CVD and emerging knowledge on the heterogeneity of OSA. We discuss the varied mechanistic pathways that result in CVD that also vary across subgroups of OSA, as well as the potential role of new biomarkers for CVD risk stratification.
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Affiliation(s)
- Susan Redline
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA.
- Harvard Medical School, Boston, MA, USA.
| | - Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Yüksel Peker
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
- Koc University School of Medicine, Istanbul, Turkey
- University of Gothenburg, Gothenburg, Sweden
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Lund University School of Medicine, Lund, Sweden
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O'Driscoll DM, Young AC. Contemporary Concise Review 2022: Sleep. Respirology 2023; 28:518-524. [PMID: 36990762 DOI: 10.1111/resp.14500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 03/15/2023] [Indexed: 03/31/2023]
Abstract
COVID-19 AND SLEEP: The COVID-19 pandemic is associated with an increase in insomnia and impaired sleep quality Health care workers are particularly susceptible and improved with cognitive behavioural therapy for insomnia (CBT-I) Long COVID has significant effects on sleep OSA impacts on the severity of acute COVID-19 illness OBSTRUCTIVE SLEEP APNOEA: Large trials of clinically representative patients confirm the cardiovascular benefits of CPAP treatment in OSA CPAP may improve long-term cognitive outcomes in OSA, but further research is needed Racial disparities in OSA prevalence and mortality risk are becoming evident Periodic evaluation of OSA risk in pregnancy is important as timing may be key for intervention to prevent or treat cardiovascular risk factors INSOMNIA: Comorbid insomnia and obstructive sleep apnoea (COMISA) can frequently co-exist and the combined negative effects of both may be deleterious, particularly to cardiovascular health There is evidence for effectiveness with novel orexin receptor antagonists.
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Affiliation(s)
- Denise M O'Driscoll
- Department of Respiratory and Sleep Medicine, Eastern Health, Box Hill, Victoria, Australia
- Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia
| | - Alan C Young
- Department of Respiratory and Sleep Medicine, Eastern Health, Box Hill, Victoria, Australia
- Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia
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30
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Martinez-Garcia MA, Sánchez-de-la-Torre M, White DP, Azarbarzin A. Hypoxic Burden in Obstructive Sleep Apnea: Present and Future. Arch Bronconeumol 2023; 59:36-43. [PMID: 36115739 DOI: 10.1016/j.arbres.2022.08.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 08/12/2022] [Indexed: 12/27/2022]
Abstract
Conventional measures of obstructive sleep apnea (OSA) severity, such as the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) are commonly used to quantify OSA severity and guide therapeutical decision-making processes. However, it is widely recognized that both AHI and ODI have important limitations and novel physiologically-informed metrics are needed to better capture the severity of OSA and characterize its physiological consequences, particularly the severity of recurrent nocturnal hypoxemia, ensuing the respiratory events. According to recent studies, the sleep apnea-specific "hypoxic burden (HB)", defined as the sum of individual areas under the oxygen desaturation curve, has shown some promise in identifying high risk individuals with OSA. In addition to the frequency of respiratory events, HB capture the depth and duration of OSA-related hypoxemia that may prove to be important disease characterizing features, not captured by the conventional "frequency-based" metrics, such as AHI and ODI. In this "perspective" paper the methods to quantify the HB, its characteristics, associations with health outcomes, and its limitations will be discussed.
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Affiliation(s)
- Miguel A Martinez-Garcia
- Respiratory Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain.
| | - Manuel Sánchez-de-la-Torre
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain; Precision Medicine in Chronic Diseases, Hospital Universitari Arnau de Vilanova-Santa Maria, IRB Lleida, Department of Nursing and Physiotherapy, Faculty of Nursing and Physiotherapy, University of Lleida, Lleida, Spain
| | - David P White
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
| | - Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
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Yuan H, Liu J, Gu Y, Ji X, Nan G. Intermittent hypoxia conditioning as a potential prevention and treatment strategy for ischemic stroke: Current evidence and future directions. Front Neurosci 2022; 16:1067411. [PMID: 36507357 PMCID: PMC9732261 DOI: 10.3389/fnins.2022.1067411] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/11/2022] [Indexed: 11/26/2022] Open
Abstract
Ischemic stroke (IS) is the leading cause of disability and death worldwide. Owing to the aging population and unhealthy lifestyles, the incidence of cerebrovascular disease is high. Vascular risk factors include hypertension, diabetes, dyslipidemia, and obesity. Therefore, in addition to timely and effective reperfusion therapy for IS, it is crucial to actively control these risk factors to reduce the incidence and recurrence rates of IS. Evidence from human and animal studies suggests that moderate intermittent hypoxia (IH) exposure is a promising therapeutic strategy to ameliorate common vascular risk factors and comorbidities. Given the complex pathophysiological mechanisms underlying IS, effective treatment must focus on reducing injury in the acute phase and promoting repair in the recovery phase. Therefore, this review discusses the preclinical perspectives on IH conditioning as a potential treatment for neurovascular injury and highlights IH pre and postconditioning strategies for IS. Hypoxia conditioning reduces brain injury by increasing resistance to acute ischemic and hypoxic stress, exerting neuroprotective effects, and promoting post-injury repair and regeneration. However, whether IH produces beneficial effects depends not only on the hypoxic regimen but also on inter-subject differences. Therefore, we discuss the factors that may influence the effectiveness of IH treatment, including age, sex, comorbidities, and circadian rhythm, which can be used to help identify the optimal intervention population and treatment protocols for more accurate, individualized clinical translation. In conclusion, IH conditioning as a non-invasive, non-pharmacological, systemic, and multi-targeted intervention can not only reduce brain damage after stroke but can also be applied to the prevention and functional recovery of IS, providing brain protection at different stages of the disease. It represents a promising therapeutic strategy. For patients with IS and high-risk groups, IH conditioning is expected to develop as an adjunctive clinical treatment option to reduce the incidence, recurrence, disability, and mortality of IS and to reduce disease burden.
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Affiliation(s)
- Honghua Yuan
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Jia Liu
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Capital Medical University, Beijing, China
| | - Yuhang Gu
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Xunming Ji
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Capital Medical University, Beijing, China,Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China,*Correspondence: Xunming Ji,
| | - Guangxian Nan
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, China,Guangxian Nan,
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Lizamore CA, Stoner L, Kathiravel Y, Elliott J, Hamlin MJ. Does intermittent hypoxic exposure enhance the cardioprotective effect of exercise in an inactive population? Front Physiol 2022; 13:1005113. [DOI: 10.3389/fphys.2022.1005113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 11/08/2022] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to determine whether exercise supplemented with passive intermittent hypoxic exposure (IHE) improved overall cardiovascular disease risk and individual risk factors. Participants were randomized to exercise-only (Ex, n = 18, 5 males, 13 females; age: 56.4 ± 6.5 years; weight: 81.2 ± 15.9; height: 167.3 ± 8.42) or exercise + IHE (IHE + Ex, n = 16; 6 males, 10 females; age: 56.7 ± 6.4 years; weight: 78.6 ± 12.4 kg; height: 168.0 ± 8.8 cm). Both groups received the same strength and aerobic exercise training (1 h, 3 days/wk, 10 weeks). IHE + Ex also received IHE (5 min hypoxia: 5 min ambient air ×6) for 2–3 days/wk. Measurements were collected before (Baseline), after (Post), and 4- and 8-week following the intervention. There were small, beneficial reductions in overall 5- year cardiovascular risk in both groups. At Post, for IHE + Ex compared to IHE there were unclear to likely improvements in high density lipoprotein (8.0% ± 8.0%), systolic blood pressure (−3.4% ± 3.4%) and VO2peak (3.1% ± 7.7%). These improvements persisted at 8-week. There was an unclear improvement in arterial wave reflection (augmentation index) at Post (−6.1% ± 18.4%, unclear), but became very likely harmful at 8-week (8-week: 24.8% ± 19.7%). The conflicting findings indicate that in inactive adults, the addition of IHE to exercise may be beneficial to systemic markers of cardiovascular health but may also increase myocardial load due to increased arterial wave reflection.
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Hypoxic Burden in Obstructive Sleep Apnea: Present and Future. Arch Bronconeumol 2022:S0300-2896(22)00524-5. [PMID: 36127216 DOI: 10.1016/j.arbres.2022.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/24/2022]
Abstract
Conventional measures of obstructive sleep apnea (OSA) severity, such as the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) are commonly used to quantify OSA severity and guide therapeutical decision-making processes. However, it is widely recognized that both AHI and ODI have important limitations and novel physiologically informed metrics are needed to better capture the severity of OSA and characterize its physiological consequences, particularly the severity of recurrent nocturnal hypoxemia, ensuing the respiratory events. According to recent studies, the sleep apnea-specific "Hypoxic Burden (HB)", defined as the sum of individual areas under the oxygen desaturation curve, has shown some promise in identifying high risk individuals with OSA. In addition to the frequency of respiratory events, HB capture the depth and duration of OSA-related hypoxemia that may prove to be important disease characterizing features, not captured by the conventional "frequency-based" metrics, such as AHI and ODI. In this "Perspective" paper the methods to quantify the HB, its characteristics, associations with health outcomes, and its limitations will be discussed.
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34
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Panza GS, Puri S, Lin HS, Badr MS, Mateika JH. Reply to Chen et al.: Mild Intermittent Hypoxia: A New Treatment Approach for Patients with Obstructive Sleep Apnea and Hypertension. Am J Respir Crit Care Med 2022; 206:123-124. [PMID: 35476606 PMCID: PMC9954335 DOI: 10.1164/rccm.202202-0228le] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Gino S. Panza
- John D. Dingell Veterans Affairs Medical CenterDetroit, Michigan,Wayne State University School of MedicineDetroit, Michigan
| | - Shipra Puri
- John D. Dingell Veterans Affairs Medical CenterDetroit, Michigan,Wayne State University School of MedicineDetroit, Michigan
| | - Ho-Sheng Lin
- John D. Dingell Veterans Affairs Medical CenterDetroit, Michigan,Wayne State University School of MedicineDetroit, Michigan
| | - M. Safwan Badr
- John D. Dingell Veterans Affairs Medical CenterDetroit, Michigan,Wayne State University School of MedicineDetroit, Michigan
| | - Jason H. Mateika
- John D. Dingell Veterans Affairs Medical CenterDetroit, Michigan,Wayne State University School of MedicineDetroit, Michigan,Corresponding author (e-mail: )
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35
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Chen R, Zhao D, Wu Q, Chen X, Lin J, Wang D, Chen M, Lin J, Zheng Z. Mild Intermittent Hypoxia: A New Treatment Approach for Patients with Obstructive Sleep Apnea and Hypertension. Am J Respir Crit Care Med 2022; 206:122-123. [PMID: 35476716 PMCID: PMC9954325 DOI: 10.1164/rccm.202201-0134le] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Riken Chen
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China,State Key Laboratory of Respiratory DiseaseGuangzhou, Guangdong, China,Guangzhou Institute of Respiratory DiseaseGuangzhou, Guangdong, China,National Clinical Research Center for Respiratory DiseaseGuangzhou, Guangdong, China
| | - Dongxing Zhao
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China,State Key Laboratory of Respiratory DiseaseGuangzhou, Guangdong, China,Guangzhou Institute of Respiratory DiseaseGuangzhou, Guangdong, China,National Clinical Research Center for Respiratory DiseaseGuangzhou, Guangdong, China
| | - Qinglan Wu
- Central People's Hospital of ZhanjiangZhanjiang, Guangdong, China
| | - Xiaojuan Chen
- Medical College of Jiaying UniversityMeizhou, Guangdong, China
| | - Jiangpeng Lin
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China,State Key Laboratory of Respiratory DiseaseGuangzhou, Guangdong, China,Guangzhou Institute of Respiratory DiseaseGuangzhou, Guangdong, China,National Clinical Research Center for Respiratory DiseaseGuangzhou, Guangdong, China
| | - Donghao Wang
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China,State Key Laboratory of Respiratory DiseaseGuangzhou, Guangdong, China,Guangzhou Institute of Respiratory DiseaseGuangzhou, Guangdong, China,National Clinical Research Center for Respiratory DiseaseGuangzhou, Guangdong, China
| | - Mingdi Chen
- The Second Affiliated Hospital of Guangdong Medical UniversityZhanjiang, Guangdong, China
| | - Junyan Lin
- The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou, Guangdong, China,State Key Laboratory of Respiratory DiseaseGuangzhou, Guangdong, China,Guangzhou Institute of Respiratory DiseaseGuangzhou, Guangdong, China,National Clinical Research Center for Respiratory DiseaseGuangzhou, Guangdong, China
| | - Zhenzhen Zheng
- The Second Affiliated Hospital of Guangdong Medical UniversityZhanjiang, Guangdong, China,Corresponding author (e-mail: )
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36
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Panza GS, Puri S, Lin HS, Mateika JH. Divergent Ventilatory and Blood Pressure Responses are Evident Following Repeated Daily Exposure to Mild Intermittent Hypoxia in Males with OSA and Hypertension. Front Physiol 2022; 13:897978. [PMID: 35721527 PMCID: PMC9204590 DOI: 10.3389/fphys.2022.897978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022] Open
Abstract
Introduction: Resting minute ventilation and ventilation during and following hypoxia may be enhanced following daily exposure to mild intermittent hypoxia (MIH). In contrast, resting systolic blood pressure (SBP) is reduced following daily exposure to MIH. However, it is presently unknown if the reduction in resting SBP following daily exposure, is coupled with reduced SBP responses during and after acute exposure to MIH. Methods: Participants with obstructive sleep apnea (OSA) and hypertension (n = 10) were exposed to twelve 2-min bouts of MIH (oxygen saturation—87%)/day for 15 days. A control group (n = 6) was exposed to a sham protocol during which compressed air (i.e., FIO2 = 0.21) was inspired in place of MIH. Results: The hypoxic ventilatory response (HVR) and hypoxic systolic blood pressure response (HSBP) increased from the first to the last hypoxic episode on the initial (HVR: 0.08 ± 0.02 vs. 0.13 ± 0.02 L/min/mmHg, p = 0.03; HSBP: 0.13 ± 0.04 vs. 0.37 ± 0.06 mmHg/mmHg, p < 0.001) and final (HVR: 0.10 ± 0.01 vs. 0.15 ± 0.03 L/min/mmHg, p = 0.03; HSBP: 0.16 ± 0.03 vs. 0.41 ± 0.34 mmHg/mmHg, p < 0.001) day. The magnitude of the increase was not different between days (p ≥ 0.83). Following exposure to MIH, minute ventilation and SBP was elevated compared to baseline on the initial (MV: 16.70 ± 1.10 vs. 14.20 ± 0.28 L/min, p = 0.01; SBP: 167.26 ± 4.43 vs. 151.13 ± 4.56 mmHg, p < 0.001) and final (MV: 17.90 ± 1.25 vs. 15.40 ± 0.77 L/min, p = 0.01; SBP: 156.24 ± 3.42 vs. 137.18 ± 4.17 mmHg, p < 0.001) day. The magnitude of the increases was similar on both days (MV: 3.68 ± 1.69 vs. 3.22 ± 1.27 L/min, SBP: 14.83 ± 2.64 vs. 14.28 ± 1.66 mmHg, p ≥ 0.414). Despite these similarities, blood pressure at baseline and at other time points during the MIH protocol was reduced on the final compared to the initial day (p ≤ 0.005). Conclusion: The ventilatory and blood pressure responses during and following acute MIH were similar on the initial and final day of exposure. Alternatively, blood pressure was down regulated, while ventilation was similar at all time points (i.e., baseline, during and following MIH) after daily exposure to MIH.
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Affiliation(s)
- Gino S Panza
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, United States.,Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Shipra Puri
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, United States.,Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Ho-Sheng Lin
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, United States.,Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Jason H Mateika
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI, United States.,Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States.,Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI, United States
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Affiliation(s)
- Danny J. Eckert
- Adelaide Institute for Sleep HealthFlinders UniversityBedford Park, South Australia, Australia
| | - Scott A. Sands
- Division of Sleep MedicineBrigham and Women’s Hospital and Harvard Medical SchoolBoston, Massachusetts
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