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Mann DL, Staykov E, Georgeson T, Azarbarzin A, Kainulainen S, Redline S, Sands SA, Terrill PI. Flow Limitation Is Associated with Excessive Daytime Sleepiness in Individuals without Moderate or Severe Obstructive Sleep Apnea. Ann Am Thorac Soc 2024; 21:1186-1193. [PMID: 38530665 PMCID: PMC11298983 DOI: 10.1513/annalsats.202308-710oc] [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: 08/17/2023] [Accepted: 03/20/2024] [Indexed: 03/28/2024] Open
Abstract
Rationale: Moderate-severe obstructive sleep apnea (OSA) (apnea-hypopnea index [AHI], >15 events/h) disturbs sleep through frequent bouts of apnea and is associated with daytime sleepiness. However, many individuals without moderate-severe OSA (i.e., AHI <15 events/h) also report sleepiness. Objectives: To test the hypothesis that sleepiness in the AHI <15 events/h group is a consequence of substantial flow limitation in the absence of overt reductions in airflow (i.e., apnea/hypopnea). Methods: A total of 1,886 participants from the MESA sleep cohort were analyzed for frequency of flow limitation from polysomnogram-recorded nasal airflow signal. Excessive daytime sleepiness (EDS) was defined by an Epworth Sleepiness Scale score ⩾11. Covariate-adjusted logistic regression assessed the association between EDS (binary dependent variable) and frequency of flow limitation (continuous) in individuals with an AHI <15 events/h. Results: A total of 772 individuals with an AHI <15 events/h were included in the primary analysis. Flow limitation was associated with EDS (odds ratio, 2.04; 95% confidence interval, 1.17-3.54; per 2-standard deviation increase in flow limitation frequency) after adjusting for age, sex, body mass index, race/ethnicity, and sleep duration. This effect size did not appreciably change after also adjusting for AHI. Conclusions: In individuals with an AHI <15 events/h, increasing flow limitation frequency by 2 standard deviations is associated with a twofold increase in the risk of EDS. Future studies should investigate addressing flow limitation in low-AHI individuals as a potential mechanism for ameliorating sleepiness.
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Affiliation(s)
- Dwayne L. Mann
- School of Electrical Engineering and Computer Science
- Institute for Social Science Research, and
| | - Eric Staykov
- School of Electrical Engineering and Computer Science
| | - Thomas Georgeson
- Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Samu Kainulainen
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; and
- Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland
| | - Susan Redline
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Scott A. Sands
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts
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Luo YM, Chen YY, Liang SF, Wu LG, Wellman A, McEvoy RD, Steier J, Eckert DJ, Polkey MI. Central sleep apnea treated by a constant low-dose CO 2 supplied by a novel device. J Appl Physiol (1985) 2023; 135:977-984. [PMID: 37675475 DOI: 10.1152/japplphysiol.00312.2023] [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: 05/15/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/08/2023] Open
Abstract
CO2 inhalation has been previously reported as a treatment for central sleep apnea both when associated with heart failure or where the cause is unknown. Here, we evaluated a novel CO2 supply system using a novel open mask capable of comfortably delivering a constantly inspired fraction of CO2 ([Formula: see text]) during sleep. We recruited 18 patients with central sleep apnea (13 patients with cardiac disease, and 5 patients idiopathic) diagnosed by diaphragm electromyogram (EMG) recordings made during overnight full polysomnography (PSG) (night 1). In each case, the optimal [Formula: see text] was determined by an overnight manual titration with PSG (night 2). Titration commenced at 1% CO2 and increased by 0.2% increments until central sleep apnea (CSA) disappeared. Patients were then treated on the third night (night 3) with the lowest therapeutically effective concentration of CO2 derived from night 2. Comparing night 1 and night 3, both apnea-hypopnea index (AHI; 31 ± 14 vs. 6 ± 3 events/h, P < 0.01) and arousal index (22 ± 8 vs. 15 ± 8 events/h, P < 0.01) were significantly improved during CO2 treatment. Sleep efficiency improved from 71 ± 18 to 80 ± 11%, P < 0.05, and sleep latency was shorter (23 ± 18 vs. 10 ± 10 min, P < 0.01). Heart rate was not different between night 1 and night 3. Our data confirm the feasibility of our CO2 delivery system and indicate that individually titrated CO2 supplementation with a novel device including a special open mask can reduce sleep disordered breathing severity and improve sleep quality. Randomized controlled studies should now be undertaken to assess therapeutic benefit for patients with CSA.NEW & NOTEWORTHY A novel device using a special mask was developed and proved that CO2 therapy using the device could eliminate central sleep apnea (CSA) events and improve sleep quality including reducing arousal index in patients with heart failure. The device would become a useful clinical treatment for heart failure patients with CSA.
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Affiliation(s)
- Yuan-Ming Luo
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, People's Republic of China
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States
- College of Medicine and Public Health, Adelaide Institute for Sleep Health, Flinders University, Adelaide, South Australia, Australia
| | - Yong-Yi Chen
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Shan-Feng Liang
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Lu-Guang Wu
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States
| | - R Doug McEvoy
- College of Medicine and Public Health, Adelaide Institute for Sleep Health, Flinders University, Adelaide, South Australia, Australia
| | - Joerg Steier
- Lane Fox Respiratory Unit/Sleep Disorders Centre, London, United Kingdom
| | - Danny J Eckert
- College of Medicine and Public Health, Adelaide Institute for Sleep Health, Flinders University, Adelaide, South Australia, Australia
| | - Michael I Polkey
- Royal Brompton Hospital, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
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3
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Dempsey JA, Welch JF. Control of Breathing. Semin Respir Crit Care Med 2023; 44:627-649. [PMID: 37494141 DOI: 10.1055/s-0043-1770342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Substantial advances have been made recently into the discovery of fundamental mechanisms underlying the neural control of breathing and even some inroads into translating these findings to treating breathing disorders. Here, we review several of these advances, starting with an appreciation of the importance of V̇A:V̇CO2:PaCO2 relationships, then summarizing our current understanding of the mechanisms and neural pathways for central rhythm generation, chemoreception, exercise hyperpnea, plasticity, and sleep-state effects on ventilatory control. We apply these fundamental principles to consider the pathophysiology of ventilatory control attending hypersensitized chemoreception in select cardiorespiratory diseases, the pathogenesis of sleep-disordered breathing, and the exertional hyperventilation and dyspnea associated with aging and chronic diseases. These examples underscore the critical importance that many ventilatory control issues play in disease pathogenesis, diagnosis, and treatment.
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Affiliation(s)
- Jerome A Dempsey
- John Rankin Laboratory of Pulmonary Medicine, Department of Population Health Sciences, University of Wisconsin, Madison, Wisconsin
| | - Joseph F Welch
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
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4
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Dempsey JA, Gibbons TD. Rethinking O 2 , CO 2 and breathing during wakefulness and sleep. J Physiol 2023. [PMID: 37750243 DOI: 10.1113/jp284551] [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: 06/20/2023] [Accepted: 09/11/2023] [Indexed: 09/27/2023] Open
Abstract
We have examined the importance of three long-standing questions concerning chemoreceptor influences on cardiorespiratory function which are currently experiencing a resurgence of study among physiologists and clinical investigators. Firstly, while carotid chemoreceptors (CB) are required for hypoxic stimulation of breathing, use of an isolated, extracorporeally perfused CB preparation in unanaesthetized animals with maintained tonic input from the CB, reveals that extra-CB hypoxaemia also provides dose-dependent ventilatory stimulation sufficient to account for 40-50% of the total ventilatory response to steady-state hypoxaemia. Extra-CB hyperoxia also provides a dose- and time-dependent hyperventilation. Extra-CB sites of O2 -driven ventilatory stimulation identified to date include the medulla, kidney and spinal cord. Secondly, using the isolated or denervated CB preparation in awake animals and humans has demonstrated a hyperadditive effect of CB sensory input on central CO2 sensitivity, so that tonic CB activity accounts for as much as 35-40% of the normal, air-breathing eupnoeic drive to breathe. Thirdly, we argue for a key role for CO2 chemoreception and the neural drive to breathe in the pathogenesis of upper airway obstruction during sleep (OSA), based on the following evidence: (1) removal of the wakefulness drive to breathe enhances the effects of transient CO2 changes on breathing instability; (2) oscillations in respiratory motor output precipitate pharyngeal obstruction in sleeping subjects with compliant, collapsible airways; and (3) in the majority of patients in a large OSA cohort, a reduced neural drive to breathe accompanied reductions in both airflow and pharyngeal airway muscle dilator activity, precipitating airway obstruction.
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Affiliation(s)
| | - Travis D Gibbons
- University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
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5
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Souza GMPR, Stornetta DS, Shi Y, Lim E, Berry FE, Bayliss DA, Abbott SBG. Neuromedin B-Expressing Neurons in the Retrotrapezoid Nucleus Regulate Respiratory Homeostasis and Promote Stable Breathing in Adult Mice. J Neurosci 2023; 43:5501-5520. [PMID: 37290937 PMCID: PMC10376939 DOI: 10.1523/jneurosci.0386-23.2023] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/10/2023] Open
Abstract
Respiratory chemoreceptor activity encoding arterial Pco2 and Po2 is a critical determinant of ventilation. Currently, the relative importance of several putative chemoreceptor mechanisms for maintaining eupneic breathing and respiratory homeostasis is debated. Transcriptomic and anatomic evidence suggests that bombesin-related peptide Neuromedin-B (Nmb) expression identifies chemoreceptor neurons in the retrotrapezoid nucleus (RTN) that mediate the hypercapnic ventilatory response, but functional support is missing. In this study, we generated a transgenic Nmb-Cre mouse and used Cre-dependent cell ablation and optogenetics to test the hypothesis that RTN Nmb neurons are necessary for the CO2-dependent drive to breathe in adult male and female mice. Selective ablation of ∼95% of RTN Nmb neurons causes compensated respiratory acidosis because of alveolar hypoventilation, as well as profound breathing instability and respiratory-related sleep disruption. Following RTN Nmb lesion, mice were hypoxemic at rest and were prone to severe apneas during hyperoxia, suggesting that oxygen-sensitive mechanisms, presumably the peripheral chemoreceptors, compensate for the loss of RTN Nmb neurons. Interestingly, ventilation following RTN Nmb -lesion was unresponsive to hypercapnia, but behavioral responses to CO2 (freezing and avoidance) and the hypoxia ventilatory response were preserved. Neuroanatomical mapping shows that RTN Nmb neurons are highly collateralized and innervate the respiratory-related centers in the pons and medulla with a strong ipsilateral preference. Together, this evidence suggests that RTN Nmb neurons are dedicated to the respiratory effects of arterial Pco2/pH and maintain respiratory homeostasis in intact conditions and suggest that malfunction of these neurons could underlie the etiology of certain forms of sleep-disordered breathing in humans.SIGNIFICANCE STATEMENT Respiratory chemoreceptors stimulate neural respiratory motor output to regulate arterial Pco2 and Po2, thereby maintaining optimal gas exchange. Neurons in the retrotrapezoid nucleus (RTN) that express the bombesin-related peptide Neuromedin-B are proposed to be important in this process, but functional evidence has not been established. Here, we developed a transgenic mouse model and demonstrated that RTN neurons are fundamental for respiratory homeostasis and mediate the stimulatory effects of CO2 on breathing. Our functional and anatomic data indicate that Nmb-expressing RTN neurons are an integral component of the neural mechanisms that mediate CO2-dependent drive to breathe and maintain alveolar ventilation. This work highlights the importance of the interdependent and dynamic integration of CO2- and O2-sensing mechanisms in respiratory homeostasis of mammals.
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Affiliation(s)
- George M P R Souza
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Daniel S Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Yingtang Shi
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Eunu Lim
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Faye E Berry
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Stephen B G Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
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Perger E, Bertoli S, Lombardi C. Pharmacotherapy for obstructive sleep apnea: targeting specific pathophysiological traits. Expert Rev Respir Med 2023; 17:663-673. [PMID: 37646222 DOI: 10.1080/17476348.2023.2241353] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 07/24/2023] [Indexed: 09/01/2023]
Abstract
INTRODUCTION The pathophysiology of obstructive sleep apnea (OSA) is multi-factorial and complex. Varying OSA's pathophysiological traits have been identified, including pharyngeal collapsibility, upper airway muscle reactivity, arousal threshold, and regulation of the ventilatory drive. Being CPAP of difficult tolerance and other interventions reserved to specific subpopulations new pharmacological treatments for OSA might be resolutive. AREAS COVERED Several existing and newly developed pharmacological drugs can impact one or more endotypes and could therefore be proposed as treatment options for sleep disordered breathing. With this review we will explore different pathophysiological traits as new targets for OSA therapy. This review will summarize the most promising pharmacological treatment for OSA accordingly with their mechanisms of action on upper airway collapsibility, muscle responsiveness, arousal threshold, and loop gain. EXPERT OPINION Only understanding the pathophysiological traits causing OSA in each patient and placing the disease in the framework of patient comorbidities, we will be able to evolve interventions toward OSA. The development of new drug's combinations will permit different approaches and different choices beside conventional treatments. In the next future, we hope that sleep specialists will select the treatment for a specific patient on the base of its pathophysiology, defining a precision medicine for OSA.
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Affiliation(s)
- Elisa Perger
- Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, Milan, Italy
| | - Simona Bertoli
- Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, Milan, Italy
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy
- Lab of Nutrition and Obesity Research, Istituto Auxologico Italiano, IRCCS, Milan, Carolina
| | - Carolina Lombardi
- Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, Milan, Italy
- Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
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7
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Lv R, Liu X, Zhang Y, Dong N, Wang X, He Y, Yue H, Yin Q. Pathophysiological mechanisms and therapeutic approaches in obstructive sleep apnea syndrome. Signal Transduct Target Ther 2023; 8:218. [PMID: 37230968 DOI: 10.1038/s41392-023-01496-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/27/2023] Open
Abstract
Obstructive sleep apnea syndrome (OSAS) is a common breathing disorder in sleep in which the airways narrow or collapse during sleep, causing obstructive sleep apnea. The prevalence of OSAS continues to rise worldwide, particularly in middle-aged and elderly individuals. The mechanism of upper airway collapse is incompletely understood but is associated with several factors, including obesity, craniofacial changes, altered muscle function in the upper airway, pharyngeal neuropathy, and fluid shifts to the neck. The main characteristics of OSAS are recurrent pauses in respiration, which lead to intermittent hypoxia (IH) and hypercapnia, accompanied by blood oxygen desaturation and arousal during sleep, which sharply increases the risk of several diseases. This paper first briefly describes the epidemiology, incidence, and pathophysiological mechanisms of OSAS. Next, the alterations in relevant signaling pathways induced by IH are systematically reviewed and discussed. For example, IH can induce gut microbiota (GM) dysbiosis, impair the intestinal barrier, and alter intestinal metabolites. These mechanisms ultimately lead to secondary oxidative stress, systemic inflammation, and sympathetic activation. We then summarize the effects of IH on disease pathogenesis, including cardiocerebrovascular disorders, neurological disorders, metabolic diseases, cancer, reproductive disorders, and COVID-19. Finally, different therapeutic strategies for OSAS caused by different causes are proposed. Multidisciplinary approaches and shared decision-making are necessary for the successful treatment of OSAS in the future, but more randomized controlled trials are needed for further evaluation to define what treatments are best for specific OSAS patients.
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Affiliation(s)
- Renjun Lv
- The First School of Clinical Medicine, Lanzhou University, Lanzhou, 730000, China
| | - Xueying Liu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China
| | - Yue Zhang
- Department of Geriatrics, the 2nd Medical Center, Chinese PLA General Hospital, Beijing, 100853, China
| | - Na Dong
- The First School of Clinical Medicine, Lanzhou University, Lanzhou, 730000, China
| | - Xiao Wang
- The First School of Clinical Medicine, Lanzhou University, Lanzhou, 730000, China
| | - Yao He
- The First School of Clinical Medicine, Lanzhou University, Lanzhou, 730000, China
| | - Hongmei Yue
- Department of Pulmonary and Critical Care Medicine, The First Hospital of Lanzhou University, Lanzhou, 730000, China.
| | - Qingqing Yin
- Department of Geriatric Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China.
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8
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Rojas-Córdova S, Torres-Fraga MG, Rodríguez-Reyes YG, Guerrero-Zúñiga S, Vázquez-García JC, Carrillo-Alduenda JL. Altitude and Breathing during Sleep in Healthy Persons and Sleep Disordered Patients: A Systematic Review. Sleep Sci 2023; 16:117-126. [PMID: 37151770 PMCID: PMC10157825 DOI: 10.1055/s-0043-1767745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 06/28/2022] [Indexed: 05/09/2023] Open
Abstract
Objetive The aim of this systematic review is to analyze the recent scientific evidence of the clinical effects of altitude on breathing during sleep in healthy persons and sleep disordered patients. Material and Methods A search was carried out in PubMed and Scopus looking for articles published between January 1, 2010 and December 31, 2021, in English and Spanish, with the following search terms: "sleep disorders breathing and altitude". Investigations in adults and carried out at an altitude of 2000 meters above mean sea level (MAMSL) or higher were included. The correlation between altitude, apnea hypopnea index (AHI) and mean SpO2 during sleep was calculated. Results 18 articles of the 112 identified were included. A good correlation was found between altitude and AHI (Rs = 0.66 P = 0.001), at the expense of an increase in the central apnea index. Altitude is inversely proportional to oxygenation during sleep (Rs = -0.93 P = 0.001), and an increase in the desaturation index was observed (3% and 4%). On the treatment of respiratory disorders of sleeping at altitude, oxygen is better than servoventilation to correct oxygenation during sleep in healthy subjects and acetazolamide controlled respiratory events and oxygenation during sleep in patients with obstructive sleep apnea under treatment with CPAP. Conclusions Altitude increases AHI and decreases oxygenation during sleep; oxygen and acetazolamide could be an effective treatment for sleep-disordered breathing at altitude above 2000 MAMSL.
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Affiliation(s)
| | | | | | - Selene Guerrero-Zúñiga
- National Institute of Respiratory Diseases, Sleep Medicine Unit, Mexico City, Mexico City, Mexico
| | | | - José Luis Carrillo-Alduenda
- National Institute of Respiratory Diseases, Sleep Medicine Unit, Mexico City, Mexico City, Mexico
- Address for correspondence José Luis Carrillo-Alduenda
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9
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Duong-Quy S, Nguyen-Huu H, Hoang-Chau-Bao D, Tran-Duc S, Nguyen-Thi-Hong L, Nguyen-Duy T, Tang-Thi-Thao T, Phan C, Bui-Diem K, Vu-Tran-Thien Q, Nguyen-Ngoc-Phuong T, Nguyen-Nhu V, Le-Thi-Minh H, Craig T. Personalized Medicine and Obstructive Sleep Apnea. J Pers Med 2022; 12:2034. [PMID: 36556255 PMCID: PMC9781564 DOI: 10.3390/jpm12122034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/27/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
Obstructive sleep apnea (OSA) is a common disease that is often under-diagnosed and under-treated in all ages. This is due to differences in morphology, diversity in clinical phenotypes, and differences in diagnosis and treatment of OSA in children and adults, even among individuals of the same age. Therefore, a personalized medicine approach to diagnosis and treatment of OSA is necessary for physicians in clinical practice. In children and adults without serious underlying medical conditions, polysomnography at sleep labs may be an inappropriate and inconvenient testing modality compared to home sleep apnea testing. In addition, the apnea-hypopnea index should not be considered as a single parameter for making treatment decisions. Thus, the treatment of OSA should be personalized and based on individual tolerance to sleep-quality-related parameters measured by the microarousal index, harmful effects of OSA on the cardiovascular system related to severe hypoxia, and patients' comorbidities. The current treatment options for OSA include lifestyle modification, continuous positive airway pressure (CPAP) therapy, oral appliance, surgery, and other alternative treatments. CPAP therapy has been recommended as a cornerstone treatment for moderate-to-severe OSA in adults. However, not all patients can afford or tolerate CPAP therapy. This narrative review seeks to describe the current concepts and relevant approaches towards personalized management of patients with OSA, according to pathophysiology, cluster analysis of clinical characteristics, adequate combined therapy, and the consideration of patients' expectations.
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Affiliation(s)
- Sy Duong-Quy
- Sleep Lab Centre, Lam Dong Medical College, Dalat City 0263, Vietnam
- Immuno-Allergology Division, Hershey Medical Center, Penn State Medical College, Hershey, PA 15747, USA
- Sleep Lab Unit, Outpatient Department, Pham Ngoc Thach Medical University, Ho Chi Minh City 0028, Vietnam
- Department of Respiratory Functional Exploration, University Medical Center, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 0028, Vietnam
| | - Hoang Nguyen-Huu
- Medical Education Center, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 0028, Vietnam
| | - Dinh Hoang-Chau-Bao
- Sleep Lab Unit, Outpatient Department, Pham Ngoc Thach Medical University, Ho Chi Minh City 0028, Vietnam
| | - Si Tran-Duc
- Sleep Lab Unit, Outpatient Department, Pham Ngoc Thach Medical University, Ho Chi Minh City 0028, Vietnam
| | - Lien Nguyen-Thi-Hong
- Immuno-Allergology Department, Hai Phong Medical University, Hai Phong City 0225, Vietnam
| | - Thai Nguyen-Duy
- National Institute for Control of Vaccines and Biologicals, Ministry of Health, Hanoi City 0024, Vietnam
| | | | - Chandat Phan
- Immuno-Allergology Division, Hershey Medical Center, Penn State Medical College, Hershey, PA 15747, USA
| | - Khue Bui-Diem
- Department of Physiology-Pathophysiology-Immunology, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 0028, Vietnam
| | - Quan Vu-Tran-Thien
- Department of Respiratory Functional Exploration, University Medical Center, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 0028, Vietnam
- Department of Physiology-Pathophysiology-Immunology, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 0028, Vietnam
| | - Thu Nguyen-Ngoc-Phuong
- Sleep Lab Unit, Outpatient Department, Pham Ngoc Thach Medical University, Ho Chi Minh City 0028, Vietnam
| | - Vinh Nguyen-Nhu
- Department of Respiratory Functional Exploration, University Medical Center, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 0028, Vietnam
| | - Huong Le-Thi-Minh
- Pediatric Centre, Vinmec Times City International Hospital, Hanoi City 0024, Vietnam
| | - Timothy Craig
- Sleep Lab Centre, Lam Dong Medical College, Dalat City 0263, Vietnam
- Immuno-Allergology Division, Hershey Medical Center, Penn State Medical College, Hershey, PA 15747, USA
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10
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Gell LK, Vena D, Alex RM, Azarbarzin A, Calianese N, Hess LB, Taranto-Montemurro L, White DP, Wellman A, Sands SA. Neural ventilatory drive decline as a predominant mechanism of obstructive sleep apnoea events. Thorax 2022; 77:707-716. [PMID: 35064045 PMCID: PMC10039972 DOI: 10.1136/thoraxjnl-2021-217756] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 10/18/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND In the classic model of obstructive sleep apnoea (OSA), respiratory events occur with sleep-related dilator muscle hypotonia, precipitating increased neural ventilatory 'drive'. By contrast, a drive-dependent model has been proposed, whereby falling drive promotes dilator muscle hypotonia to precipitate respiratory events. Here we determine the extent to which the classic versus drive-dependent models of OSA are best supported by direct physiological measurements. METHODS In 50 OSA patients (5-91 events/hour), we recorded ventilation ('flow', oronasal mask and pneumotach) and ventilatory drive (calibrated intraoesophageal diaphragm electromyography, EMG) overnight. Flow and drive during events were ensemble averaged; patients were classified as drive dependent if flow fell/rose simultaneously with drive. Overnight effects of lower drive on flow, genioglossus muscle activity (EMGgg) and event risk were quantified (mixed models). RESULTS On average, ventilatory drive fell (rather than rose) during events (-20 (-42 to 3)%baseline, median (IQR)) and was strongly correlated with flow (R=0.78 (0.24 to 0.94)). Most patients (30/50, 60%) were classified as exhibiting drive-dependent event pathophysiology. Lower drive during sleep was associated with lower flow (-17 (-20 to -14)%/drive) and EMGgg (-3.5 (-3.8 to -3.3)%max/drive) and greater event risk (OR: 2.2 (1.8 to 2.5) per drive reduction of 100%eupnoea); associations were concentrated in patients with drive-dependent OSA (ie, flow: -37 (-40 to -34)%/drive, OR: 6.8 (5.3 to 8.7)). Oesophageal pressure-without tidal volume correction-falsely suggested rising drive during events (classic model). CONCLUSIONS In contrast to the prevailing view, patients with OSA predominantly exhibit drive-dependent event pathophysiology, whereby flow is lowest at nadir drive, and lower drive raises event risk. Preventing ventilatory drive decline is therefore considered a target for OSA intervention.
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Affiliation(s)
- Laura K Gell
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Daniel Vena
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Raichel M Alex
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Nicole Calianese
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Lauren B Hess
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Luigi Taranto-Montemurro
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - David P White
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Scott A Sands
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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11
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Luo YM, Polkey MI. Being obstructive in sleep apnoea: more of a drive than a load problem? Thorax 2022; 77:640. [DOI: 10.1136/thoraxjnl-2021-218437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2021] [Indexed: 11/03/2022]
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12
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Messineo L, Eckert DJ, Taranto-Montemurro L, Vena D, Azarbarzin A, Hess LB, Calianese N, White DP, Wellman A, Gell L, Sands SA. Ventilatory Drive Withdrawal Rather Than Reduced Genioglossus Compensation as a Mechanism of Obstructive Sleep Apnea in REM Sleep. Am J Respir Crit Care Med 2022; 205:219-232. [PMID: 34699338 PMCID: PMC8787251 DOI: 10.1164/rccm.202101-0237oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Rationale: REM sleep is associated with reduced ventilation and greater obstructive sleep apnea (OSA) severity than non-REM (nREM) sleep for reasons that have not been fully elucidated. Objectives: Here, we use direct physiological measurements to determine whether the pharyngeal compromise in REM sleep OSA is most consistent with 1) withdrawal of neural ventilatory drive or 2) deficits in pharyngeal pathophysiology per se (i.e., increased collapsibility and decreased muscle responsiveness). Methods: Sixty-three participants with OSA completed sleep studies with gold standard measurements of ventilatory "drive" (calibrated intraesophageal diaphragm EMG), ventilation (oronasal "ventilation"), and genioglossus EMG activity. Drive withdrawal was assessed by examining these measurements at nadir drive (first decile of drive within a stage). Pharyngeal physiology was assessed by examining collapsibility (lowered ventilation at eupneic drive) and responsiveness (ventilation-drive slope). Mixed-model analysis compared REM sleep with nREM sleep; sensitivity analysis examined phasic REM sleep. Measurements and Main Results: REM sleep (⩾10 min) was obtained in 25 patients. Compared with drive in nREM sleep, drive in REM sleep dipped to markedly lower nadir values (first decile, estimate [95% confidence interval], -21.8% [-31.2% to -12.4%] of eupnea; P < 0.0001), with an accompanying reduction in ventilation (-25.8% [-31.8% to -19.8%] of eupnea; P < 0.0001). However, there was no effect of REM sleep on collapsibility (ventilation at eupneic drive), baseline genioglossus EMG activity, or responsiveness. REM sleep was associated with increased OSA severity (+10.1 [1.8 to 19.8] events/h), but this association was not present after adjusting for nadir drive (+4.3 [-4.2 to 14.6] events/h). Drive withdrawal was exacerbated in phasic REM sleep. Conclusions: In patients with OSA, the pharyngeal compromise characteristic of REM sleep appears to be predominantly explained by ventilatory drive withdrawal rather than by preferential decrements in muscle activity or responsiveness. Preventing drive withdrawal may be the leading target for REM sleep OSA.
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Affiliation(s)
- Ludovico Messineo
- Adelaide Institute for Sleep Health, Flinders University, Bedford Park, Adelaide, South Australia, Australia;,Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Danny J. Eckert
- Adelaide Institute for Sleep Health, Flinders University, Bedford Park, Adelaide, South Australia, Australia
| | - Luigi Taranto-Montemurro
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Daniel Vena
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Lauren B. Hess
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Nicole Calianese
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - David P. White
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Laura Gell
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and
| | - Scott A. Sands
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts; and,Department of Allergy Immunology and Respiratory Medicine, Central Clinical School, The Alfred and Monash University, Melbourne, Victoria, Australia
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13
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Schmickl CN, Landry S, Orr JE, Nokes B, Edwards BA, Malhotra A, Owens RL. Effects of acetazolamide on control of breathing in sleep apnea patients: Mechanistic insights using meta-analyses and physiological model simulations. Physiol Rep 2021; 9:e15071. [PMID: 34699135 PMCID: PMC8547551 DOI: 10.14814/phy2.15071] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/14/2021] [Accepted: 09/18/2021] [Indexed: 11/24/2022] Open
Abstract
Obstructive and central sleep apnea affects ~1 billion people globally and may lead to serious cardiovascular and neurocognitive consequences, but treatment options are limited. High loop gain (ventilatory instability) is a major pathophysiological mechanism underlying both types of sleep apnea and can be lowered pharmacologically with acetazolamide, thereby improving sleep apnea severity. However, individual responses vary and are strongly correlated with the loop gain reduction achieved by acetazolamide. To aid with patient selection for long-term trials and clinical care, our goal was to understand better the factors that determine the change in loop gain following acetazolamide in human subjects with sleep apnea. Thus, we (i) performed several meta-analyses to clarify how acetazolamide affects ventilatory control and loop gain (including its primary components controller/plant gain), and based on these results, we (ii) performed physiological model simulations to assess how different baseline conditions affect the change in loop gain. Our results suggest that (i) acetazolamide primarily causes a left shift of the chemosensitivity line thus lowering plant gain without substantially affecting controller gain; and (ii) higher controller gain, higher paCO2 at eupneic ventilation, and lower CO2 production at baseline result in a more pronounced loop gain reduction with acetazolamide. In summary, the combination of mechanistic meta-analyses with model simulations provides a unified framework of acetazolamide's effects on ventilatory control and revealed physiological predictors of response, which are consistent with empirical observations of acetazolamide's effects in different sleep apnea subgroups. Prospective studies are needed to validate these predictors and assess their value for patient selection.
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Affiliation(s)
- Christopher N. Schmickl
- Division of Pulmonary, Critical Care and Sleep MedicineUniversity of California, San Diego (UCSD)La JollaCaliforniaUSA
| | - Shane Landry
- Department of PhysiologySleep and Circadian Medicine LaboratorySchool of Biomedical Sciences and Biomedical Discovery InstituteMonash UniversityMelbourneVictoriaAustralia
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneVictoriaAustralia
| | - Jeremy E. Orr
- Division of Pulmonary, Critical Care and Sleep MedicineUniversity of California, San Diego (UCSD)La JollaCaliforniaUSA
| | - Brandon Nokes
- Division of Pulmonary, Critical Care and Sleep MedicineUniversity of California, San Diego (UCSD)La JollaCaliforniaUSA
| | - Bradley A. Edwards
- Department of PhysiologySleep and Circadian Medicine LaboratorySchool of Biomedical Sciences and Biomedical Discovery InstituteMonash UniversityMelbourneVictoriaAustralia
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneVictoriaAustralia
| | - Atul Malhotra
- Division of Pulmonary, Critical Care and Sleep MedicineUniversity of California, San Diego (UCSD)La JollaCaliforniaUSA
| | - Robert L. Owens
- Division of Pulmonary, Critical Care and Sleep MedicineUniversity of California, San Diego (UCSD)La JollaCaliforniaUSA
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14
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Pun M, Beaudin AE, Raneri JK, Anderson TJ, Hanly PJ, Poulin MJ. Impact of nocturnal oxygen and CPAP on the ventilatory response to hypoxia in OSA patients free of overt cardiovascular disease. Exp Neurol 2021; 346:113852. [PMID: 34461058 DOI: 10.1016/j.expneurol.2021.113852] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 08/17/2021] [Accepted: 08/24/2021] [Indexed: 11/20/2022]
Abstract
A primary characteristic of obstructive sleep apnea (OSA) is chronic exposure to intermittent hypoxia (IH) due to repeated upper airway obstruction. Chronic IH exposure is believed to increase OSA severity over time by enhancing the acute ventilatory response to hypoxia (AHVR), thus promoting ventilatory overshoot when apnea ends and perpetuation of apnea during sleep. Continuous positive airway pressure (CPAP), the gold-standard treatment of OSA, reduces the AHVR, believed to result from correction of IH. However, CPAP also corrects ancillary features of OSA such as intermittent hypercapnia, negative intrathoracic pressure and surges in sympathetic activity, which may also contribute to the reduction in AHVR. Therefore, the objective of this study was to investigate the impact of nocturnal oxygen therapy (to remove IH only) and CPAP (to correct IH and ancillary features of OSA) on AHVR in newly diagnosed OSA patients. Fifty-two OSA patients and twenty-two controls were recruited. The AHVR was assessed using a 5 min iscopanic-hypoxic challenge before, and after, treatment of OSA by nocturnal oxygen therapy and CPAP. Following baseline measurements, OSA patients were randomly assigned to nocturnal oxygen therapy (Oxygen, n = 26) or no treatment (Air; n = 26). The AHVR was re-assessed following two weeks of oxygen therapy or no treatment, after which all patients were treated with CPAP. The AHVR was quantified following ~4 weeks of adherent CPAP therapy (n = 40). Both nocturnal oxygen and CPAP treatments improved hypoxemia (p < 0.05), and, as expected, nocturnal oxygen therapy did not completely abolish respiratory events (i.e., apneas/hypopneas). Averaged across all OSA patients, nocturnal oxygen therapy did not change AHVR from baseline to post-oxygen therapy. Similarly, the AHVR was not altered pre- and post-CPAP (p > 0.05). However, there was a significant decrease in AHVR with both nocturnal oxygen therapy and CPAP in patients in the highest OSA severity quartile (p < 0.05). Nocturnal oxygen therapy and CPAP both reduce the AHVR in patients with the most severe OSA. Therefore, IH appears to be the primary mechanism producing ventilatory instability in patients with severe OSA via enhancement of the AHVR.
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Affiliation(s)
- Matiram Pun
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Andrew E Beaudin
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jill K Raneri
- Sleep Centre, Foothills Medical Centre, Calgary, AB, Canada
| | - Todd J Anderson
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Cardiac Science, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Patrick J Hanly
- Sleep Centre, Foothills Medical Centre, Calgary, AB, Canada; Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - Marc J Poulin
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.
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15
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Genta PR, Schorr F, Edwards BA, Wellman A, Lorenzi-Filho G. Discriminating the severity of pharyngeal collapsibility in men using anthropometric and polysomnographic indices. J Clin Sleep Med 2021; 16:1531-1537. [PMID: 32441245 DOI: 10.5664/jcsm.8600] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
STUDY OBJECTIVES Although obstructive sleep apnea results from the combination of different pathophysiologic mechanisms, the degree of anatomical compromise remains the main responsible factor. The passive pharyngeal critical closing pressure (Pcrit) is a technique used to assess the collapsibility of the upper airway and is often used as a surrogate measure of this anatomical compromise. Patients with a low Pcrit (ie, less collapsible airway) are potential candidates for non-continuous positive airway pressure therapies. However, Pcrit determination is a technically complex method not available in clinical practice. We hypothesized that the discrimination between low and high Pcrit can be estimated from simple anthropometric and polysomnographic indices. METHODS Men with and without obstructive sleep apnea underwent Pcrit determination and full polysomnography. Receiver operating characteristics analysis was performed to select the best cutoff of each variable to predict a high Pcrit (Pcrit ≥ 2.5 cmH₂O). Multiple logistic regression analysis was performed to create a clinical score to predict a high Pcrit. RESULTS We studied 81 men, 48 ± 13 years of age, with an apnea-hypopnea index of 32 [14-60], range 1-96 events/h), and Pcrit of -0.7 ± 3.1 (range, -9.1 to +7.2 cmH₂O). A high and low Pcrit could be accurately identified by polysomnographic and anthropometric indices. A score to discriminate Pcrit showed good performance (area under the curve = 0.96; 95% confidence interval, 0.91-1.00) and included waist circumference, non-rapid eye movement obstructive apnea index/apnea-hypopnea index, mean obstructive apnea duration, and rapid eye movement apnea-hypopnea index. CONCLUSIONS A low Pcrit (less collapsible) can be estimated from a simple clinical score. This approach may identify candidates more likely to respond to non-continuous positive airway pressure therapies for obstructive sleep apnea.
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Affiliation(s)
- Pedro R Genta
- Laboratorio do Sono, LIM 63, Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas HCFMUSP, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Fabiola Schorr
- Laboratorio do Sono, LIM 63, Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas HCFMUSP, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Bradley A Edwards
- Sleep and Circadian Medicine Laboratory, Department of Physiology, Monash University, Melbourne, Victoria, Australia.,School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, Victoria, Australia
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Geraldo Lorenzi-Filho
- Laboratorio do Sono, LIM 63, Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas HCFMUSP, Universidade de Sao Paulo, Sao Paulo, Brazil
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16
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Zeineddine S, Rowley JA, Chowdhuri S. Oxygen Therapy in Sleep-Disordered Breathing. Chest 2021; 160:701-717. [PMID: 33610579 DOI: 10.1016/j.chest.2021.02.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 11/29/2022] Open
Abstract
Sleep-disordered breathing (SDB) is highly prevalent in adults and leads to significant cardiovascular and neurologic sequelae. Intermittent hypoxia during sleep is a direct consequence of SDB. Administration of nocturnal supplemental oxygen (NSO) has been used as a therapeutic alternative to positive airway pressure (PAP) in SDB. NSO significantly improves oxygen saturation in OSA but is inferior to PAP in terms of reducing apnea severity and may prolong the duration of obstructive apneas. The effect of NSO on daytime sleepiness remains unclear, but NSO may improve physical function-related quality of life in OSA. Its effects on BP reduction remain inconclusive. The effects of NSO vs PAP in OSA with comorbid COPD (overlap syndrome) are unknown. NSO is effective in reducing central sleep apnea related to congestive heart failure; however, its impact on mortality and cardiovascular clinical outcomes are being investigated in an ongoing clinical trial. In conclusion, studies are inconclusive or limited regarding clinical outcomes with oxygen therapy compared with sham or PAP therapy in patients with OSA and overlap syndrome. Oxygen does mitigate central sleep apnea. This review examines the crucial knowledge gaps and suggests future research priorities to clarify the effects of optimal dose and duration of NSO, alone or in combination with PAP, on cardiovascular, sleep, and cognitive outcomes.
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Affiliation(s)
- Salam Zeineddine
- Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center, Detroit, MI; Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, MI
| | - James A Rowley
- Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, MI
| | - Susmita Chowdhuri
- Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center, Detroit, MI; Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, MI.
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17
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Baddam P, Biancardi V, Roth DM, Eaton F, Thereza-Bussolaro C, Mandal R, Wishart DS, Barr A, MacLean J, Flores-Mir C, Pagliardini S, Graf D. Neural crest-specific deletion of Bmp7 leads to midfacial hypoplasia, nasal airway obstruction, and disordered breathing modelling Obstructive Sleep Apnea. Dis Model Mech 2021; 14:dmm.047738. [PMID: 33431521 PMCID: PMC7888714 DOI: 10.1242/dmm.047738] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/22/2020] [Indexed: 12/14/2022] Open
Abstract
Pediatric obstructive sleep apnea (OSA), a relatively common sleep-related breathing disorder (SRBD) affecting approximately 1-5% of children, is often caused by anatomical obstruction and/or collapse of the nasal and/or pharyngeal airways. The resulting sleep disruption and intermittent hypoxia lead to various systemic morbidities. Predicting the development of OSA from craniofacial features alone is currently not possible and a controversy remains if upper airway obstruction facilitates reduced midfacial growth or vice-versa. Currently, there is no rodent model that recapitulates both the development of craniofacial abnormalities and upper airway obstruction to address these questions. Here, we describe that mice with a neural crest-specific deletion of Bmp7 (Bmp7ncko) present with shorter, more acute angled cranial base, midfacial hypoplasia, nasal septum deviation, turbinate swelling and branching defects, and nasal airway obstruction. Interestingly, several of these craniofacial features develop after birth during periods of rapid midfacial growth and precede the development of an upper airway obstruction. We identified that in this rodent model, no single feature appeared to predict upper airway obstruction, but the sum of those features resulted in a reduced breathing frequency, apneas and overall reduced oxygen consumption. Metabolomics analysis of serum from peripheral blood identified increased levels of hydroxyproline, a metabolite upregulated under hypoxic conditions. As this model recapitulates many features observed in OSA, it offers unique opportunities for studying how upper airway obstruction affects breathing physiology and leads to systemic morbidities.
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Affiliation(s)
- Pranidhi Baddam
- School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Vivian Biancardi
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Equal contributions
| | - Daniela M Roth
- School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Equal contributions
| | - Farah Eaton
- School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Claudine Thereza-Bussolaro
- School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Department of Dentistry, Hospital dos Pinheiros, UNIFASIPE, Sinop, Mato Grosso, Brazil
| | - Rupasri Mandal
- The Metabolomics Innovation Centre, Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, AB, Canada
| | - David S Wishart
- The Metabolomics Innovation Centre, Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, AB, Canada
| | - Amy Barr
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Joanna MacLean
- Department of Pediatrics and the Women & Children's Health Research Institute, Faculty of Medicine and Dentistry, University of Alberta
- Stollery Children's Hospital; Edmonton, AB, Canada
| | - Carlos Flores-Mir
- School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Silvia Pagliardini
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Daniel Graf
- School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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18
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Rastogi R, Badr MS, Ahmed A, Chowdhuri S. Amelioration of sleep-disordered breathing with supplemental oxygen in older adults. J Appl Physiol (1985) 2020; 129:1441-1450. [PMID: 32969781 DOI: 10.1152/japplphysiol.00253.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Elderly adults demonstrate increased propensity for breathing instability during sleep compared with younger adults, and this may contribute to increased prevalence of sleep-disordered breathing (SDB) in this population. Hence, in older adults with SDB, we examined whether addition of supplemental oxygen (O2) will stabilize breathing during sleep and alleviate SDB. We hypothesized that exposure to supplemental O2 during non-rapid eye movement (NREM) sleep will stabilize breathing and will alleviate SDB by reducing ventilatory chemoresponsiveness and by widening the carbon dioxide (CO2) reserve. We studied 10 older adults with mild-to-moderate SDB who were randomized to undergo noninvasive bilevel mechanical ventilation with exposure to room air or supplemental O2 (Oxy) to determine the CO2 reserve, apneic threshold (AT), and controller and plant gains. Supplemental O2 was introduced during sleep to achieve a steady-state O2 saturation ≥95% and fraction of inspired O2 at 40%-50%. The CO2 reserve increased significantly during Oxy versus room air (-4.2 ± 0.5 mmHg vs. -3.2 ± 0.5 mmHg, P = 0.03). Compared with room air, Oxy was associated with a significant decline in the controller gain (1.9 ± 0.4 L/min/mmHg vs. 2.5 ± 0.5 L/min/mmHg, P = 0.04), with reductions in the apnea-hypopnea index (11.8 ± 2.0/h vs. 24.4 ± 5.6/h, P = 0.006) and central apnea-hypopnea index (1.7 ± 0.6/h vs. 6.9 ± 3.9/h, P = 0.03). The AT and plant gain were unchanged. Thus, a reduced slope of CO2 response resulted in an increased CO2 reserve. In conclusion, supplemental O2 reduced SDB in older adults during NREM sleep via reduction in chemoresponsiveness and central respiratory events.NEW & NOTEWORTHY This study demonstrates for the first time in elderly adults without heart disease that intervention with supplemental oxygen in the clinical range will ameliorate central apneas and hypopneas by decreasing the propensity to central apnea through decreased chemoreflex sensitivity, even in the absence of a reduction in the plant gain. Thus, the study provides physiological evidence for use of supplemental oxygen as therapy for mild-to-moderate SDB in this vulnerable population.
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Affiliation(s)
- Ruchi Rastogi
- Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan.,Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, Michigan
| | - M S Badr
- Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan.,Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, Michigan
| | - A Ahmed
- Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, Michigan
| | - S Chowdhuri
- Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan.,Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, Michigan
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19
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Cross-sectional study of loop gain abnormalities in childhood obstructive sleep apnea syndrome. Sleep Med 2020; 69:172-178. [DOI: 10.1016/j.sleep.2020.01.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 11/22/2022]
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20
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Targeting Endotypic Traits with Medications for the Pharmacological Treatment of Obstructive Sleep Apnea. A Review of the Current Literature. J Clin Med 2019; 8:jcm8111846. [PMID: 31684047 PMCID: PMC6912255 DOI: 10.3390/jcm8111846] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 12/28/2022] Open
Abstract
Obstructive sleep apnea (OSA) is a highly prevalent condition with few therapeutic options. To date there is no approved pharmacotherapy for this disorder, but several attempts have been made in the past and are currently ongoing to find one. The recent identification of multiple endotypes underlying this disorder has oriented the pharmacological research towards tailored therapies targeting specific pathophysiological traits that contribute differently to cause OSA in each patient. In this review we retrospectively analyze the literature on OSA pharmacotherapy dividing the medications tested on the basis of the four main endotypes: anatomy, upper airway muscle activity, arousal threshold and ventilatory instability (loop gain). We show how recently introduced drugs for weight loss that modify upper airway anatomy may play an important role in the management of OSA in the near future, and promising results have been obtained with drugs that increase upper airway muscle activity during sleep and reduce loop gain. The lack of a medication that can effectively increase the arousal threshold makes this strategy less encouraging, although recent studies have shown that the use of certain sedatives do not worsen OSA severity and could actually improve patients' sleep quality.
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21
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Edwards BA, Redline S, Sands SA, Owens RL. More Than the Sum of the Respiratory Events: Personalized Medicine Approaches for Obstructive Sleep Apnea. Am J Respir Crit Care Med 2019; 200:691-703. [PMID: 31022356 PMCID: PMC6775874 DOI: 10.1164/rccm.201901-0014tr] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 04/22/2019] [Indexed: 11/16/2022] Open
Abstract
Traditionally, the presence and severity of obstructive sleep apnea (OSA) have been defined by the apnea-hypopnea index (AHI). Continuous positive airway pressure is generally first-line therapy despite low adherence, because it reliably reduces the AHI when used, and the response to other therapies is variable. However, there is growing appreciation that the underlying etiology (i.e., endotype) and clinical manifestation (i.e., phenotype) of OSA in an individual are not well described by the AHI. We define and review the important progress made in understanding and measuring physiological mechanisms (or endotypes) that help define subtypes of OSA and identify the potential use of genetics to further refine disease classification. This more detailed understanding of OSA pathogenesis should influence clinical treatment decisions as well as help inform research priorities and clinical study design. In short, treatments could be individualized on the basis of the underlying cause of OSA; patients could better understand which symptoms and outcomes will respond to OSA treatment and by how much; and researchers could select populations most likely to benefit from specific treatment approaches for OSA.
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Affiliation(s)
- Bradley A. Edwards
- Sleep and Circadian Medicine Laboratory, Department of Physiology, and
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, Victoria, Australia
- Division of Sleep and Circadian Disorders, Department of Medicine and Department of Neurology, Brigham & Women’s Hospital and Harvard Medical School, Boston, Massachusetts; and
| | - Susan Redline
- Division of Sleep and Circadian Disorders, Department of Medicine and Department of Neurology, Brigham & Women’s Hospital and Harvard Medical School, Boston, Massachusetts; and
| | - Scott A. Sands
- Division of Sleep and Circadian Disorders, Department of Medicine and Department of Neurology, Brigham & Women’s Hospital and Harvard Medical School, Boston, Massachusetts; and
| | - Robert L. Owens
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California, San Diego, La Jolla, California
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An act of balance: Interaction of central and peripheral chemosensitivity with inflammatory and anti-inflammatory factors in obstructive sleep apnoea. Respir Physiol Neurobiol 2019; 266:73-81. [DOI: 10.1016/j.resp.2019.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 02/05/2023]
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Abstract
Central sleep apnea is prevalent in patients with heart failure, healthy individuals at high altitudes, and chronic opiate users and in the initiation of "mixed" (that is, central plus obstructive apneas). This brief review focuses on (a) the causes of repetitive, cyclical central apneas as mediated primarily through enhanced sensitivities in the respiratory control system and (b) treatment of central sleep apnea through modification of key components of neurochemical control as opposed to the current universal use of positive airway pressure.
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Affiliation(s)
- Jerome A. Dempsey
- Department of Population Health Sciences, University of Wisconsin - Madison, WARF Building, 7th Floor, 614 Walnut Street, Madison, WI 53726, USA
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24
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Webster JG, Shokoueinejad M, Wang F. A Sleep Apnea Therapy Device Uses No Added Pressure. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:6030-3035. [PMID: 30441711 DOI: 10.1109/embc.2018.8513679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sleep Apnea is a common sleeping disorder that affects over 25 million Americans. Due to the complex nature of sleep apnea, and the human body, neither an effective nor comfortable treatment option for sleep apnea has been developed. Accordingly, we describe a novel alternative to current sleep apnea therapies, including CPAP therapy. A comfortable device for treating sleep apnea incorporates a mask, a flexible hose and a chamber for collecting expired air containing CO2. A sensor detects apnea and a control system automatically adjusts the amount of rebreathed CO2 minimize apnea and also minimize arousal.
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25
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Sands SA, Edwards BA, Terrill PI, Butler JP, Owens RL, Taranto-Montemurro L, Azarbarzin A, Marques M, Hess LB, Smales ET, de Melo CM, White DP, Malhotra A, Wellman A. Identifying obstructive sleep apnoea patients responsive to supplemental oxygen therapy. Eur Respir J 2018; 52:13993003.00674-2018. [PMID: 30139771 DOI: 10.1183/13993003.00674-2018] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 07/29/2018] [Indexed: 11/05/2022]
Abstract
A possible precision-medicine approach to treating obstructive sleep apnoea (OSA) involves targeting ventilatory instability (elevated loop gain) using supplemental inspired oxygen in selected patients. Here we test whether elevated loop gain and three key endophenotypic traits (collapsibility, compensation and arousability), quantified using clinical polysomnography, can predict the effect of supplemental oxygen on OSA severity.36 patients (apnoea-hypopnoea index (AHI) >20 events·h-1) completed two overnight polysomnographic studies (single-blinded randomised-controlled crossover) on supplemental oxygen (40% inspired) versus sham (air). OSA traits were quantified from the air-night polysomnography. Responders were defined by a ≥50% reduction in AHI (supine non-rapid eye movement). Secondary outcomes included blood pressure and self-reported sleep quality.Nine of 36 patients (25%) responded to supplemental oxygen (ΔAHI=72±5%). Elevated loop gain was not a significant univariate predictor of responder/non-responder status (primary analysis). In post hoc analysis, a logistic regression model based on elevated loop gain and other traits (better collapsibility and compensation; cross-validated) had 83% accuracy (89% before cross-validation); predicted responders exhibited an improvement in OSA severity (ΔAHI 59±6% versus 12±7% in predicted non-responders, p=0.0001) plus lowered morning blood pressure and "better" self-reported sleep.Patients whose OSA responds to supplemental oxygen can be identified by measuring their endophenotypic traits using diagnostic polysomnography.
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Affiliation(s)
- Scott A Sands
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.,Dept of Allergy, Immunology and Respiratory Medicine and Central Clinical School, The Alfred and Monash University, Melbourne, Australia
| | - Bradley A Edwards
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.,Sleep and Circadian Medicine Laboratory, Dept of Physiology, Monash University, Melbourne, Australia.,School of Psychological Sciences, Monash University, Melbourne, Australia.,Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, Australia
| | - Philip I Terrill
- School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Australia
| | - James P Butler
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Robert L Owens
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.,Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, La Jolla, CA, USA
| | - Luigi Taranto-Montemurro
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Melania Marques
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Lauren B Hess
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Erik T Smales
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Camila M de Melo
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - David P White
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Atul Malhotra
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.,Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, La Jolla, CA, USA
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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26
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Messineo L, Taranto‐Montemurro L, Azarbarzin A, Oliveira Marques MD, Calianese N, White DP, Wellman A, Sands SA. Breath-holding as a means to estimate the loop gain contribution to obstructive sleep apnoea. J Physiol 2018; 596:4043-4056. [PMID: 29882226 PMCID: PMC6117550 DOI: 10.1113/jp276206] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 05/30/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS A hypersensitive ventilatory control system or elevated "loop gain" during sleep is a primary phenotypic trait causing obstructive sleep apnoea (OSA). Despite the multitude of methods available to assess the anatomical contributions to OSA during wakefulness in the clinical setting (e.g. neck circumference, pharyngometry, Mallampati score), it is currently not possible to recognize elevated loop gain in patients in this context. Loop gain during sleep can now be recognized using simplified testing during wakefulness, specifically in the form of a reduced maximal breath-hold duration, or a larger ventilatory response to voluntary 20-second breath-holds. We consider that easy breath-holding manoeuvres will enable daytime recognition of a high loop gain in OSA for more personalized intervention. ABSTRACT Increased "loop gain" of the ventilatory control system promotes obstructive sleep apnoea (OSA) in some patients and offers an avenue for more personalized treatment, yet diagnostic tools for directly measuring loop gain in the clinical setting are lacking. Here we test the hypothesis that elevated loop gain during sleep can be recognized using voluntary breath-hold manoeuvres during wakefulness. Twenty individuals (10 OSA, 10 controls) participated in a single overnight study with voluntary breath-holding manoeuvres performed during wakefulness. We assessed (1) maximal breath-hold duration, and (2) the ventilatory response to 20 s breath-holds. For comparison, gold standard loop gain values were obtained during non-rapid eye movement (non-REM) sleep using the ventilatory response to 20 s pulses of hypoxic-hypercapnic gas (6% CO2 -14% O2 , mimicking apnoea). Continuous positive airway pressure (CPAP) was used to maintain airway patency during sleep. Additional measurements included gold standard loop gain measurement during wakefulness and steady-state loop gain measurement during sleep using CPAP dial-ups. Higher loop gain during sleep was associated with (1) a shorter maximal breath-hold duration (r2 = 0.49, P < 0.001), and (2) a larger ventilatory response to 20 s breath-holds during wakefulness (second breath; r2 = 0.50, P < 0.001); together these factors combine to predict high loop gain (receiver operating characteristic area-under-curve: 92%). Gold standard loop gain values were remarkably similar during wake and non-REM sleep. The results show that elevated loop gain during sleep can be identified using simple breath-holding manoeuvres performed during wakefulness. This may have implications for personalizing OSA treatment.
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Affiliation(s)
- Ludovico Messineo
- Division of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
- Respiratory Medicine and Sleep LaboratoryDepartment of Experimental and Clinical SciencesUniversity of Brescia and Spedali CiviliBresciaItaly
| | - Luigi Taranto‐Montemurro
- Division of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - Ali Azarbarzin
- Division of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - Melania D. Oliveira Marques
- Division of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
- Pulmonary DivisionHeart Institute (InCor)Hospital das ClínicasUniversity of São Paulo School of MedicineSão PauloBrazil
| | - Nicole Calianese
- Division of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - David P. White
- Division of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - Andrew Wellman
- Division of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - Scott A. Sands
- Division of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
- Department of Allergy, Immunology and Respiratory Medicine, and Central Clinical SchoolThe Alfred and Monash UniversityMelbourneVictoriaAustralia
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Schmickl CN, Owens RL, Edwards BA, Malhotra A. OSA Endotypes: What Are They and What Are Their Potential Clinical Implications? CURRENT SLEEP MEDICINE REPORTS 2018. [DOI: 10.1007/s40675-018-0121-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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28
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Landry SA, Joosten SA, Eckert DJ, Jordan AS, Sands SA, White DP, Malhotra A, Wellman A, Hamilton GS, Edwards BA. Therapeutic CPAP Level Predicts Upper Airway Collapsibility in Patients With Obstructive Sleep Apnea. Sleep 2018; 40:3608771. [PMID: 28419320 DOI: 10.1093/sleep/zsx056] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Study Objectives Upper airway collapsibility is a key determinant of obstructive sleep apnea (OSA) which can influence the efficacy of certain non-continuous positive airway pressure (CPAP) treatments for OSA. However, there is no simple way to measure this variable clinically. The present study aimed to develop a clinically implementable tool to evaluate the collapsibility of a patient's upper airway. Methods Collapsibility, as characterized by the passive pharyngeal critical closing pressure (Pcrit), was measured in 46 patients with OSA. Associations were investigated between Pcrit and data extracted from patient history and routine polysomnography, including CPAP titration. Results Therapeutic CPAP level, demonstrated the strongest relationship to Pcrit (r2=0.51, p < .001) of all the variables investigated including apnea-hypopnea index, body mass index, sex, and age. Patients with a mildly collapsible upper airway (Pcrit ≤ -2 cmH2O) had a lower therapeutic CPAP level (6.2 ± 0.6 vs. 10.3 ± 0.4 cmH2O, p < .001) compared to patients with more severe collapsibility (Pcrit > -2 cmH2O). A therapeutic CPAP level ≤8.0 cmH2O was sensitive (89%) and specific (84%) for detecting a mildly collapsible upper airway. When applied to the independent validation data set (n = 74), this threshold maintained high specificity (91%) but reduced sensitivity (75%). Conclusions Our data demonstrate that a patient's therapeutic CPAP requirement shares a strong predictive relationship with their Pcrit and may be used to accurately differentiate OSA patients with mild airway collapsibility from those with moderate-to-severe collapsibility. Although this relationship needs to be confirmed prospectively, our findings may provide clinicians with better understanding of an individual patient's OSA phenotype, which ultimately could assist in determining which patients are most likely to respond to non-CPAP therapies.
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Affiliation(s)
- Shane A Landry
- Sleep and Circadian Medicine Laboratory, Department of Physiology, Monash University, Melbourne, Victoria, Australia.,School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, Victoria, Australia
| | - Simon A Joosten
- Monash Lung and Sleep, Monash Medical Centre, Clayton, Victoria, Australia.,School of Clinical Sciences, Monash University, Melbourne, Victoria, Australia.,Monash Partners - Epworth, Melbourne, Australia
| | - Danny J Eckert
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.,Neuroscience Research Australia (NeuRA) and the University of New South Wales, Randwick, Sydney, New South Wales, Australia
| | - Amy S Jordan
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.,Melbourne School of Psychological Sciences, University of Melbourne, Parkville, Victoria, Australia.,Institute for Breathing and Sleep, Heidelberg, Victoria, Australia
| | - Scott A Sands
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.,Department of Allergy, Immunology and Respiratory Medicine and Central Clinical School, The Alfred and Monash University, Melbourne, Victoria, Australia
| | - David P White
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Atul Malhotra
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.,Division of Pulmonary and Critical Care Medicine, University of California San Diego, CA
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Garun S Hamilton
- Monash Lung and Sleep, Monash Medical Centre, Clayton, Victoria, Australia.,School of Clinical Sciences, Monash University, Melbourne, Victoria, Australia.,Monash Partners - Epworth, Melbourne, Australia
| | - Bradley A Edwards
- Sleep and Circadian Medicine Laboratory, Department of Physiology, Monash University, Melbourne, Victoria, Australia.,School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, Victoria, Australia.,Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
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29
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Phenotypic approaches to obstructive sleep apnoea – New pathways for targeted therapy. Sleep Med Rev 2018; 37:45-59. [DOI: 10.1016/j.smrv.2016.12.003] [Citation(s) in RCA: 225] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 11/30/2016] [Accepted: 12/08/2016] [Indexed: 02/01/2023]
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Abstract
The prevalence of obstructive sleep apnea (OSA) continues to rise. So too do the health, safety, and economic consequences. On an individual level, the causes and consequences of OSA can vary substantially between patients. In recent years, four key contributors to OSA pathogenesis or "phenotypes" have been characterized. These include a narrow, crowded, or collapsible upper airway "anatomical compromise" and "non-anatomical" contributors such as ineffective pharyngeal dilator muscle function during sleep, a low threshold for arousal to airway narrowing during sleep, and unstable control of breathing (high loop gain). Each of these phenotypes is a target for therapy. This review summarizes the latest knowledge on the different contributors to OSA with a focus on measurement techniques including emerging clinical tools designed to facilitate translation of new cause-driven targeted approaches to treat OSA. The potential for some of the specific pathophysiological causes of OSA to drive some of the key symptoms and consequences of OSA is also highlighted.
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Affiliation(s)
- Amal M Osman
- Neuroscience Research Australia (NeuRA).,School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Sophie G Carter
- Neuroscience Research Australia (NeuRA).,School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Jayne C Carberry
- Neuroscience Research Australia (NeuRA).,School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Danny J Eckert
- Neuroscience Research Australia (NeuRA).,School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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Chowdhuri S, Pranathiageswaran S, Loomis-King H, Salloum A, Badr MS. Aging is associated with increased propensity for central apnea during NREM sleep. J Appl Physiol (1985) 2017; 124:83-90. [PMID: 29025898 DOI: 10.1152/japplphysiol.00125.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The reason for increased sleep-disordered breathing with predominance of central apneas in the elderly is unknown. We hypothesized that the propensity to central apneas is increased in older adults, manifested by a reduced carbon-dioxide (CO2) reserve in older compared with young adults during non-rapid eye movement sleep. Ten elderly and 15 young healthy adults underwent multiple brief trials of nasal noninvasive positive pressure ventilation during stable NREM sleep. Cessation of mechanical ventilation (MV) resulted in hypocapnic central apnea or hypopnea. The CO2 reserve was defined as the difference in end-tidal CO2 ([Formula: see text]) between eupnea and the apneic threshold, where the apneic threshold was [Formula: see text] that demarcated the central apnea closest to the eupneic [Formula: see text]. For each MV trial, the hypocapnic ventilatory response (controller gain) was measured as the change in minute ventilation (V̇e) during the MV trial for a corresponding change in [Formula: see text]. The eupneic [Formula: see text] was significantly lower in elderly vs. young adults. Compared with young adults, the elderly had a significantly reduced CO2 reserve (-2.6 ± 0.4 vs. -4.1 ± 0.4 mmHg, P = 0.01) and a higher controller gain (2.3 ± 0.2 vs. 1.4 ± 0.2 l·min-1·mmHg-1, P = 0.007), indicating increased chemoresponsiveness in the elderly. Thus elderly adults are more prone to hypocapnic central apneas owing to increased hypocapnic chemoresponsiveness during NREM sleep. NEW & NOTEWORTHY The study describes an original finding where healthy older adults compared with healthy young adults demonstrated increased breathing instability during non-rapid eye movement sleep, as suggested by a smaller carbon dioxide reserve and a higher controller gain. The findings may explain the increased propensity for central apneas in elderly adults during sleep and potentially guide the development of pathophysiology-defined personalized therapies for sleep apnea in the elderly.
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Affiliation(s)
- Susmita Chowdhuri
- Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center , Detroit, Michigan.,Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine , Detroit, Michigan
| | - Sukanya Pranathiageswaran
- Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine , Detroit, Michigan
| | - Hillary Loomis-King
- Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine , Detroit, Michigan
| | - Anan Salloum
- Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center , Detroit, Michigan.,Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine , Detroit, Michigan
| | - M Safwan Badr
- Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center , Detroit, Michigan.,Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine , Detroit, Michigan
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32
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Shokoueinejad M, Fernandez C, Carroll E, Wang F, Levin J, Rusk S, Glattard N, Mulchrone A, Zhang X, Xie A, Teodorescu M, Dempsey J, Webster J. Sleep apnea: a review of diagnostic sensors, algorithms, and therapies. Physiol Meas 2017; 38:R204-R252. [PMID: 28820743 DOI: 10.1088/1361-6579/aa6ec6] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
While public awareness of sleep related disorders is growing, sleep apnea syndrome (SAS) remains a public health and economic challenge. Over the last two decades, extensive controlled epidemiologic research has clarified the incidence, risk factors including the obesity epidemic, and global prevalence of obstructive sleep apnea (OSA), as well as establishing a growing body of literature linking OSA with cardiovascular morbidity, mortality, metabolic dysregulation, and neurocognitive impairment. The US Institute of Medicine Committee on Sleep Medicine estimates that 50-70 million US adults have sleep or wakefulness disorders. Furthermore, the American Academy of Sleep Medicine (AASM) estimates that more than 29 million US adults suffer from moderate to severe OSA, with an estimated 80% of those individuals living unaware and undiagnosed, contributing to more than $149.6 billion in healthcare and other costs in 2015. Although various devices have been used to measure physiological signals, detect apneic events, and help treat sleep apnea, significant opportunities remain to improve the quality, efficiency, and affordability of sleep apnea care. As our understanding of respiratory and neurophysiological signals and sleep apnea physiological mechanisms continues to grow, and our ability to detect and process biomedical signals improves, novel diagnostic and treatment modalities emerge. OBJECTIVE This article reviews the current engineering approaches for the detection and treatment of sleep apnea. APPROACH It discusses signal acquisition and processing, highlights the current nonsurgical and nonpharmacological treatments, and discusses potential new therapeutic approaches. MAIN RESULTS This work has led to an array of validated signal and sensor modalities for acquiring, storing and viewing sleep data; a broad class of computational and signal processing approaches to detect and classify SAS disease patterns; and a set of distinctive therapeutic technologies whose use cases span the continuum of disease severity. SIGNIFICANCE This review provides a current perspective of the classes of tools at hand, along with a sense of their relative strengths and areas for further improvement.
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Affiliation(s)
- Mehdi Shokoueinejad
- Department of Biomedical Engineering, University of Wisconsin-Madison, 1550 Engineering Drive, Madison, WI 53706-1609, United States of America. Department of Population Health Sciences, University of Wisconsin-Madison, 610 Walnut St 707, Madison, WI 53726, United States of America. EnsoData Research, EnsoData Inc., 111 N Fairchild St, Suite 240, Madison, WI 53703, United States of America
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Abstract
Purpose The purpose of this study is to test the effects of a mild degree of head-of-bed elevation (HOBE) (7.5°) on obstructive sleep apnea (OSA) severity and sleep quality. Methods OSA patients were recruited from a single sleep clinic (Criciúma, Santa Catarina, Brazil). Following a baseline polysomnography (PSG), all patients underwent a PSG with HOBE (within 2 weeks). In addition, a subset of patients performed a third PSG without HOBE. Results Fifty-two patients were included in the study (age 53.2 ± 9.1 years; BMI 29.6 ± 4.8 kg/m2, neck circumference 38.9 ± 3.8 cm, and Epworth Sleepiness Scale 15 ± 7). Compared to baseline, HOBE significantly decreased the apnea-hypopnea index (AHI) from 15.7 [11.3–22.5] to 10.7 [6.6–16.5] events/h; p < 0.001 and increased minimum oxygen saturation from 83.5 [77.5–87] to 87 [81–90]%; p = 0.003. The sleep architecture at baseline and HOBE were similar. However, sleep efficiency increased slightly but significantly with HOBE (87.2 [76.7–90.7] vs 88.8 [81.6–93.3]; p = 0.005). The AHI obtained at the third PSG without HOBE (n = 7) returned to baseline values. Conclusions Mild HOBE significantly improves OSA severity without interfering in sleep architecture and therefore is a simple alternative treatment to ameliorate OSA.
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34
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A Modeling Study on Inspired CO2 Rebreathing Device for Sleep Apnea Treatment by Means of CFD Analysis and Experiment. J Med Biol Eng 2017. [DOI: 10.1007/s40846-017-0223-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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35
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Kahwash R, Khayat RN. A Practical Approach to the Identification and Management of Sleep-Disordered Breathing in Heart Failure Patients. Sleep Med Clin 2017; 12:205-219. [PMID: 28477775 DOI: 10.1016/j.jsmc.2017.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sleep-disordered breathing (SDB) is a major health problem affecting much of the general population. Although SDB is responsible for rapid progression of heart failure (HF) and the worsening morbidity and mortality, advanced HF state is associated with accelerated development of SDB. In the face of recent developments in SDB treatment and availability of effective therapeutic options known to improve quality of life, exercise tolerance, and heart function, most HF patients with SDB are left unrecognized and untreated. This article provides an overview of SDB in HF with focus on practical approaches intended to facilitate screening and treatment.
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Affiliation(s)
- Rami Kahwash
- Section of Heart Failure and Transplant, Division of Cardiovascular Medicine, Davis Heart & Lung Research Institute, The Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA.
| | - Rami N Khayat
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Davis Heart & Lung Research Institute, The Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
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36
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Randerath W, Verbraecken J, Andreas S, Arzt M, Bloch KE, Brack T, Buyse B, De Backer W, Eckert DJ, Grote L, Hagmeyer L, Hedner J, Jennum P, La Rovere MT, Miltz C, McNicholas WT, Montserrat J, Naughton M, Pepin JL, Pevernagie D, Sanner B, Testelmans D, Tonia T, Vrijsen B, Wijkstra P, Levy P. Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep. Eur Respir J 2016; 49:13993003.00959-2016. [DOI: 10.1183/13993003.00959-2016] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/25/2016] [Indexed: 02/07/2023]
Abstract
The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerge under positive airway pressure treatment or opioid use, or at high altitude. As yet, there is insufficient knowledge on the clinical features, pathophysiological background and consecutive algorithms for stepped-care treatment. Most recently, it has been discussed intensively if CSA in heart failure is a “marker” of disease severity or a “mediator” of disease progression, and if and which type of positive airway pressure therapy is indicated. In addition, disturbances of respiratory drive or the translation of central impulses may result in hypoventilation, associated with cerebral or neuromuscular diseases, or severe diseases of lung or thorax. These statements report the results of an European Respiratory Society Task Force addressing actual diagnostic and therapeutic standards. The statements are based on a systematic review of the literature and a systematic two-step decision process. Although the Task Force does not make recommendations, it describes its current practice of treatment of CSA in heart failure and hypoventilation.
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Edwards BA, Sands SA, Owens RL, Eckert DJ, Landry S, White DP, Malhotra A, Wellman A. The Combination of Supplemental Oxygen and a Hypnotic Markedly Improves Obstructive Sleep Apnea in Patients with a Mild to Moderate Upper Airway Collapsibility. Sleep 2016; 39:1973-1983. [PMID: 27634790 DOI: 10.5665/sleep.6226] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 07/28/2016] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Obstructive sleep apnea (OSA) results from the interaction of several physiological traits; specifically a compromised upper airway anatomy and muscle function, and two key non-anatomical deficits: elevated loop gain and a low arousal threshold. Although continuous positive airway pressure (CPAP) is an efficacious treatment, it is often poorly tolerated. An alternative approach could involve administering therapies targeting the non-anatomic causes. However, therapies (oxygen or hypnotics) targeting these traits in isolation typically improve, but rarely resolve OSA. Therefore, our aim was to determine how the combination of oxygen and eszopiclone alters the phenotypic traits and OSA severity and to assess the baseline phenotypic characteristics of responders/nonresponders to combination therapy. METHODS In a single-blinded randomized crossover study, 20 OSA patients received combination therapy (3 mg eszopiclone and 40% oxygen) versus placebo/sham air, with 1 w between conditions. Under each condition, we assessed the effects on OSA severity (clinical polysomnography) and the phenotypic traits causing OSA using CPAP manipulations (research polysomnography). RESULTS Combination therapy reduced the apnea-hypopnea index (51.9 ± 6.2 vs. 29.5 ± 5.3 events/h; P < 0.001), lowered both the ventilation associated with arousal (5.7 ± 0.3 vs. 5.2 ± 0.3 L/min; P = 0.05) and loop gain (3.3 ± 0.5 vs. 2.2 ± 0.3; P = 0.025). Responders to therapy (apnea-hypopnea index reduced by > 50% to below 15 events/h; n = 9/20) had less severe OSA (P = 0.001), a less collapsible upper airway (P = 0.01) and greater upper airway muscle effectiveness (P = 0.002). CONCLUSIONS The combination of lowering loop gain and raising the arousal threshold is an effective therapy in patients whose anatomy is not severely compromised. Our work demonstrates that combining therapies that target multiple traits can resolve OSA in selected individuals. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, ID: NCT01633827.
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Affiliation(s)
- Bradley A Edwards
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA.,Sleep and Circadian Medicine Laboratory, Department of Physiology Monash University, Melbourne, VIC, Australia.,School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, VIC, Australia
| | - Scott A Sands
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA.,Department of Allergy, Immunology and Respiratory Medicine and Central Clinical School, The Alfred and Monash University, Melbourne, VIC, Australia
| | - Robert L Owens
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA.,Division of Pulmonary and Critical Care Medicine, University of California San Diego, CA
| | - Danny J Eckert
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA.,Neuroscience Research Australia (NeuRA) and the University of New South Wales, Randwick, Sydney, NSW, Australia
| | - Shane Landry
- Sleep and Circadian Medicine Laboratory, Department of Physiology Monash University, Melbourne, VIC, Australia.,School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, VIC, Australia
| | - David P White
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA
| | - Atul Malhotra
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA.,Division of Pulmonary and Critical Care Medicine, University of California San Diego, CA
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA
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Orr JE, Malhotra A, Sands SA. Pathogenesis of central and complex sleep apnoea. Respirology 2016; 22:43-52. [PMID: 27797160 DOI: 10.1111/resp.12927] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 09/22/2016] [Accepted: 10/03/2016] [Indexed: 12/01/2022]
Abstract
Central sleep apnoea (CSA) - the temporary absence or diminution of ventilatory effort during sleep - is seen in a variety of forms including periodic breathing in infancy and healthy adults at altitude and Cheyne-Stokes respiration in heart failure. In most circumstances, the cyclic absence of effort is paradoxically a consequence of hypersensitive ventilatory chemoreflex responses to oppose changes in airflow, that is elevated loop gain, leading to overshoot/undershoot ventilatory oscillations. Considerable evidence illustrates overlap between CSA and obstructive sleep apnoea (OSA), including elevated loop gain in patients with OSA and the presence of pharyngeal narrowing during central apnoeas. Indeed, treatment of OSA, whether via continuous positive airway pressure (CPAP), tracheostomy or oral appliances, can reveal CSA, an occurrence referred to as complex sleep apnoea. Factors influencing loop gain include increased chemosensitivity (increased controller gain), reduced damping of blood gas levels (increased plant gain) and increased lung to chemoreceptor circulatory delay. Sleep-wake transitions and pharyngeal dilator muscle responses effectively raise the controller gain and therefore also contribute to total loop gain and overall instability. In some circumstances, for example apnoea of infancy and central congenital hypoventilation syndrome, central apnoeas are the consequence of ventilatory depression and defective ventilatory responses, that is low loop gain. The efficacy of available treatments for CSA can be explained in terms of their effects on loop gain, for example CPAP improves lung volume (plant gain), stimulants reduce the alveolar-inspired PCO2 difference and supplemental oxygen lowers chemosensitivity. Understanding the magnitude of loop gain and the mechanisms contributing to instability may facilitate personalized interventions for CSA.
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Affiliation(s)
- Jeremy E Orr
- Division of Pulmonary and Critical Care Medicine, University of California San Diego, La Jolla, California, USA
| | - Atul Malhotra
- Division of Pulmonary and Critical Care Medicine, University of California San Diego, La Jolla, California, USA
| | - Scott A Sands
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Department of Allergy Immunology and Respiratory Medicine and Central Clinical School, The Alfred and Monash University, Melbourne, Victoria, Australia
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Treatment of Obstructive Sleep Apnea. Prospects for Personalized Combined Modality Therapy. Ann Am Thorac Soc 2016; 13:101-8. [PMID: 26569377 DOI: 10.1513/annalsats.201508-537fr] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Obstructive sleep apnea (OSA) is a common sleep disorder with serious associated morbidities. Although several treatment options are currently available, variable efficacy and adherence result in many patients either not being treated or receiving inadequate treatment long term. Personalized treatment based on relevant patient characteristics may improve adherence to treatment and long-term clinical outcomes. Four key traits of upper airway anatomy and neuromuscular control interact to varying degrees within individuals to cause OSA. These are: (1) the pharyngeal critical closing pressure, (2) the stability of ventilator chemoreflex feedback control (loop gain), (3) the negative intraesophageal pressure that triggers arousal (arousal threshold), and (4) the level of stimulus required to activated upper airway dilator muscles (upper airway recruitment threshold). Simplified diagnostic methods are being developed to assess these pathophysiological traits, potentially allowing prediction of which treatment would best suit each patient. In contrast to current practice of using various treatment modes alone, model predictions and pilot clinical trials show improved outcomes by combining several treatments targeted to each patient's pathophysiology profile. These developments could theoretically improve efficacy and adherence to treatment and in turn reduce the social and economic health burden of OSA and the associated life-threatening morbidities. This article reviews OSA pathophysiology and identifies currently available and investigational treatments that may be combined in the future to optimize therapy based on individual profiles of key patient pathophysiological traits.
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Edwards BA, Landry S, Joosten SA, Hamilton GS. Personalized Medicine for Obstructive Sleep Apnea Therapies. Sleep Med Clin 2016; 11:299-311. [DOI: 10.1016/j.jsmc.2016.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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41
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Mulchrone A, Shokoueinejad M, Webster J. A review of preventing central sleep apnea by inspired CO2. Physiol Meas 2016; 37:R36-45. [DOI: 10.1088/0967-3334/37/5/r36] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
Novel concepts and technological advances have the potential to change the landscape on which clinical sleep medicine is practiced. Screening for sleep apnea will take advantage of readily available mobile telephone technology (sound, accelerometers) to enable widespread recognition of sleep-disordered breathing. Advanced computer-assisted scoring algorithms will improve efficiency and reliability of sleep apnea diagnoses. As the field adopts a personalized approach to therapies, methods to determine the mechanisms of sleep apnea in individuals will be developed-utilizing simplified tests and available recordings-with the promise of predicting outcomes of novel therapies.
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Affiliation(s)
- Scott A Sands
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA; Department of Allergy, Immunology and Respiratory Medicine and Central Clinical School, The Alfred and Monash University, 55 Commercial Road, Prahran, Victoria 3181, Australia.
| | - Robert L Owens
- Division of Pulmonary and Critical Care Medicine, University of California San Diego, 9500 Gilman Dr La Jolla, CA 92093, USA
| | - Atul Malhotra
- Division of Pulmonary and Critical Care Medicine, University of California San Diego, 9500 Gilman Dr La Jolla, CA 92093, USA
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43
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Khayat RN, Abraham WT. Current treatment approaches and trials in central sleep apnea. Int J Cardiol 2016; 206 Suppl:S22-7. [DOI: 10.1016/j.ijcard.2016.02.126] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/21/2016] [Indexed: 02/07/2023]
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Shafazand S, Badr MS. Commentary on CPAP vs. oxygen for treatment of OSA. J Clin Sleep Med 2015; 10:1257-9. [PMID: 25325589 DOI: 10.5664/jcsm.4224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 10/09/2014] [Indexed: 12/22/2022]
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45
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Edwards BA, Eckert DJ, McSharry DG, Sands SA, Desai A, Kehlmann G, Bakker JP, Genta PR, Owens RL, White DP, Wellman A, Malhotra A. Clinical predictors of the respiratory arousal threshold in patients with obstructive sleep apnea. Am J Respir Crit Care Med 2015; 190:1293-300. [PMID: 25321848 DOI: 10.1164/rccm.201404-0718oc] [Citation(s) in RCA: 203] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
RATIONALE A low respiratory arousal threshold (ArTH) is one of several traits involved in obstructive sleep apnea pathogenesis and may be a therapeutic target; however, there is no simple way to identify patients without invasive measurements. OBJECTIVES To determine the physiologic determinates of the ArTH and develop a clinical tool that can identify patients with low ArTH. METHODS Anthropometric data were collected in 146 participants who underwent overnight polysomnography with an epiglottic catheter to measure the ArTH (nadir epiglottic pressure before arousal). The ArTH was measured from up to 20 non-REM and REM respiratory events selected randomly. Multiple linear regression was used to determine the independent predictors of the ArTH. Logistic regression was used to develop a clinical scoring system. MEASUREMENTS AND MAIN RESULTS Nadir oxygen saturation as measured by pulse oximetry, apnea-hypopnea index, and the fraction of events that were hypopneas (Fhypopneas) were independent predictors of the ArTH (r(2) = 0.59; P < 0.001). Using this information, we used receiver operating characteristic analysis and logistic regression to develop a clinical score to predict a low ArTH, which allocated a score of 1 to each criterion that was satisfied: (apnea-hypopnea index, <30 events per hour) + (nadir oxygen saturation as measured by pulse oximetry >82.5%) + (Fhypopneas >58.3%). A score of 2 or above correctly predicted a low arousal threshold in 84.1% of participants with a sensitivity of 80.4% and a specificity of 88.0%, a finding that was confirmed using leave-one-out cross-validation analysis. CONCLUSIONS Our results demonstrate that individuals with a low ArTH can be identified from standard, clinically available variables. This finding could facilitate larger interventional studies targeting the ArTH.
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Affiliation(s)
- Bradley A Edwards
- 1 Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, Massachusetts
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Terrill PI, Edwards BA, Nemati S, Butler JP, Owens RL, Eckert DJ, White DP, Malhotra A, Wellman A, Sands SA. Quantifying the ventilatory control contribution to sleep apnoea using polysomnography. Eur Respir J 2014; 45:408-18. [PMID: 25323235 DOI: 10.1183/09031936.00062914] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Elevated loop gain, consequent to hypersensitive ventilatory control, is a primary nonanatomical cause of obstructive sleep apnoea (OSA) but it is not possible to quantify this in the clinic. Here we provide a novel method to estimate loop gain in OSA patients using routine clinical polysomnography alone. We use the concept that spontaneous ventilatory fluctuations due to apnoeas/hypopnoeas (disturbance) result in opposing changes in ventilatory drive (response) as determined by loop gain (response/disturbance). Fitting a simple ventilatory control model (including chemical and arousal contributions to ventilatory drive) to the ventilatory pattern of OSA reveals the underlying loop gain. Following mathematical-model validation, we critically tested our method in patients with OSA by comparison with a standard (continuous positive airway pressure (CPAP) drop method), and by assessing its ability to detect the known reduction in loop gain with oxygen and acetazolamide. Our method quantified loop gain from baseline polysomnography (correlation versus CPAP-estimated loop gain: n=28; r=0.63, p<0.001), detected the known reduction in loop gain with oxygen (n=11; mean±sem change in loop gain (ΔLG) -0.23±0.08, p=0.02) and acetazolamide (n=11; ΔLG -0.20±0.06, p=0.005), and predicted the OSA response to loop gain-lowering therapy. We validated a means to quantify the ventilatory control contribution to OSA pathogenesis using clinical polysomnography, enabling identification of likely responders to therapies targeting ventilatory control.
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Affiliation(s)
- Philip I Terrill
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Australia
| | - Bradley A Edwards
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Shamim Nemati
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - James P Butler
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Robert L Owens
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Danny J Eckert
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA Neuroscience Research Australia and the School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - David P White
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Atul Malhotra
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA Division of Pulmonary and Critical Care, University of Southern California San Diego, La Jolla, CA, USA
| | - Andrew Wellman
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Scott A Sands
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA Central Clinical School, The Alfred and Monash University, Melbourne, Australia
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Abstract
We review the substantial recent progress made in understanding the underlying mechanisms controlling breathing and the applicability of these findings to selected human diseases. Emphasis is placed on the sites of central respiratory rhythm and pattern generation as well as newly described functions of the carotid chemoreceptors, the integrative nature of the central chemoreceptors, and the interaction between peripheral and central chemoreception. Recent findings that support critical contributions from cortical central command and muscle afferent feedback to exercise hyperpnoea are also reviewed. These basic principles, and the evidence supporting chemoreceptor and ventilatory control system plasticity during and following constant and intermittent hypoxaemia and stagnant hypoxia, are applied to: 1) the pathogenesis, consequences and treatment of obstructive sleep apnoea; and 2) exercise hyperpnoea and its control and limitations with ageing, chronic obstructive pulmonary disease and congestive heart failure.
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Affiliation(s)
- Jerome A Dempsey
- John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Curtis A Smith
- John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin-Madison, Madison, WI, USA
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Edwards BA, Sands SA, Owens RL, White DP, Genta PR, Butler JP, Malhotra A, Wellman A. Effects of hyperoxia and hypoxia on the physiological traits responsible for obstructive sleep apnoea. J Physiol 2014; 592:4523-35. [PMID: 25085887 DOI: 10.1113/jphysiol.2014.277210] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Oxygen therapy is known to reduce loop gain (LG) in patients with obstructive sleep apnoea (OSA), yet its effects on the other traits responsible for OSA remain unknown. Therefore, we assessed how hyperoxia and hypoxia alter four physiological traits in OSA patients. Eleven OSA subjects underwent a night of polysomnography during which the physiological traits were measured using multiple 3-min 'drops' from therapeutic continuous positive airway pressure (CPAP) levels. LG was defined as the ratio of the ventilatory overshoot to the preceding reduction in ventilation. Pharyngeal collapsibility was quantified as the ventilation at CPAP of 0 cmH2O. Upper airway responsiveness was defined as the ratio of the increase in ventilation to the increase in ventilatory drive across the drop. Arousal threshold was estimated as the level of ventilatory drive associated with arousal. On separate nights, subjects were submitted to hyperoxia (n = 9; FiO2 ∼0.5) or hypoxia (n = 10; FiO2 ∼0.15) and the four traits were reassessed. Hyperoxia lowered LG from a median of 3.4 [interquartile range (IQR): 2.6-4.1] to 2.1 (IQR: 1.3-2.5) (P < 0.01), but did not alter the remaining traits. By contrast, hypoxia increased LG [median: 3.3 (IQR: 2.3-4.0) vs. 6.4 (IQR: 4.5-9.7); P < 0.005]. Hypoxia additionally increased the arousal threshold (mean ± s.d. 10.9 ± 2.1 l min(-1) vs. 13.3 ± 4.3 l min(-1); P < 0.05) and improved pharyngeal collapsibility (mean ± s.d. 3.4 ± 1.4 l min(-1) vs. 4.9 ± 1.3 l min(-1); P < 0.05), but did not alter upper airway responsiveness (P = 0.7). This study demonstrates that the beneficial effect of hyperoxia on the severity of OSA is primarily based on its ability to reduce LG. The effects of hypoxia described above may explain the disappearance of OSA and the emergence of central sleep apnoea in conditions such as high altitude.
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Affiliation(s)
- Bradley A Edwards
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Scott A Sands
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Robert L Owens
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - David P White
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Pedro R Genta
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - James P Butler
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Atul Malhotra
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA Division of Pulmonary and Critical Care Medicine, University of California San Diego, San Diego, CA, USA
| | - Andrew Wellman
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Thomas RJ. Carbon dioxide in sleep medicine: the next frontier for measurement, manipulation, and research. J Clin Sleep Med 2014; 10:523-6. [PMID: 24910554 DOI: 10.5664/jcsm.3702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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50
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Perioperative Risk Modification in Patients with Obstructive Sleep Apnea. CURRENT ANESTHESIOLOGY REPORTS 2014. [DOI: 10.1007/s40140-013-0043-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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