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Avci S, Lakadamyali H, Lakadamyali H, Aydin E, Tekindal MA. Relationships among retropalatal airway, pharyngeal length, and craniofacial structures determined by magnetic resonance imaging in patients with obstructive sleep apnea. Sleep Breath 2018; 23:103-115. [DOI: 10.1007/s11325-018-1667-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 04/18/2018] [Accepted: 04/20/2018] [Indexed: 12/12/2022]
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Effect of 4-Aminopyridine on Genioglossus Muscle Activity during Sleep in Healthy Adults. Ann Am Thorac Soc 2018; 14:1177-1183. [PMID: 28387543 DOI: 10.1513/annalsats.201701-006oc] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
RATIONALE The reduction in upper airway muscle activity from wakefulness to sleep plays a key role in the development of obstructive sleep apnea. Potassium (K+) channels have been recently identified as the downstream mechanisms through which hypoglossal motoneuron membrane excitability is reduced both in non-rapid eye movement (NREM) sleep and REM sleep. In animal models, the administration of 4-aminopyridine (4-AP), a voltage-gated K+ channel blocker, increased genioglossus activity during wakefulness and across all sleep stages. OBJECTIVES We tested the hypothesis that administration of a single dose of 4-AP 10 mg extended release would increase genioglossus activity (electromyography of the genioglossus muscle [EMGGG]) during wakefulness and sleep, and thereby decrease pharyngeal collapsibility. METHODS We performed a randomized controlled crossover proof-of-concept trial in 10 healthy participants. Participants received active treatment or placebo in randomized order 3 hours before bedtime in the physiology laboratory. RESULTS EMGGG during wakefulness and NREM sleep and upper airway collapsibility measured during NREM sleep were unchanged between placebo and 4-AP nights. Tonic but not phasic EMGGG during REM sleep was higher on the 4-AP night when measured as a percentage of maximal voluntary activation (median [interquartile range] 0.3 [0.5] on placebo vs. 0.8 [1.9] %max on 4 AP; P = 0.04), but not when measured in μV or as a percentage of wakefulness value. CONCLUSIONS A single dose of 4-AP 10 mg extended release showed only a small increase in tonic EMGGG during REM sleep in this group of healthy subjects. We speculate that a higher dose of 4-AP may further increase EMGGG. However, given the potentially severe, dose-related adverse effects of this drug, including seizures, the administration of 4-AP does not appear to be an effective strategy to increase genioglossus activity during sleep in humans. Clinical Trial registered with clinicaltrials.gov (NCT02656160).
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Cori JM, Thornton T, O'Donoghue FJ, Rochford PD, White DP, Trinder J, Jordan AS. Arousal-Induced Hypocapnia Does Not Reduce Genioglossus Activity in Obstructive Sleep Apnea. Sleep 2018; 40:3608772. [PMID: 28419356 DOI: 10.1093/sleep/zsx057] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Study Objectives To determine whether arousals that terminate obstructive events in obstructive sleep apnea (OSA) (1) induce hypocapnia and (2) subsequently reduce genioglossus muscle activity following the return to sleep. Methods Thirty-one untreated patients with OSA slept instrumented with sleep staging electrodes, nasal mask and pneumotachograph, end-tidal CO2 monitoring, and intramuscular genioglossus electrodes. End-tidal CO2 was monitored, and respiratory arousals were assigned an end-arousal CO2 change value (PETCO2 on the last arousal breath minus each individual's wakefulness PETCO2). This change value, in conjunction with the normal sleep related increase in PETCO2, was used to determine whether arousals induced hypocapnia and whether the end-arousal CO2 change was associated with genioglossus muscle activity on the breaths following the return to sleep. Results Twenty-four participants provided 1137 usable arousals. Mean ± SD end-arousal CO2 change was -0.2 ± 2.4 mm Hg (below wakefulness) indicating hypocapnia typically developed during arousal. Following the return to sleep, genioglossus muscle activity did not fall below prearousal levels and was elevated for the first two breaths. End-arousal CO2 change and genioglossus muscle activity were negatively associated such that a 1 mm Hg decrease in end-arousal CO2 was associated with an ~2% increase in peak and tonic genioglossus muscle activity on the breaths following the return to sleep. Conclusions Arousal-induced hypocapnia did not result in reduced dilator muscle activity following return to sleep, and thus hypocapnia may not contribute to further obstructions via this mechanism. Elevated dilator muscle activity postarousal is likely driven by non-CO2-related stimuli.
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Affiliation(s)
- Jennifer M Cori
- Melbourne School of Psychological Sciences, University of Melbourne, Parkville, Victoria, Australia.,Institute for Breathing and Sleep and Austin Health, Heidelberg, Victoria, Australia
| | - Therese Thornton
- Melbourne School of Psychological Sciences, University of Melbourne, Parkville, Victoria, Australia.,Institute for Breathing and Sleep and Austin Health, Heidelberg, Victoria, Australia
| | - Fergal J O'Donoghue
- Institute for Breathing and Sleep and Austin Health, Heidelberg, Victoria, Australia.,Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Peter D Rochford
- Institute for Breathing and Sleep and Austin Health, Heidelberg, Victoria, Australia
| | - David P White
- Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - John Trinder
- Melbourne School of Psychological Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Amy S Jordan
- Melbourne School of Psychological Sciences, University of Melbourne, Parkville, Victoria, Australia.,Institute for Breathing and Sleep and Austin Health, Heidelberg, Victoria, Australia
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56
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Azarbarzin A, Sands SA, Marques M, Genta PR, Taranto-Montemurro L, Messineo L, White DP, Wellman A. Palatal prolapse as a signature of expiratory flow limitation and inspiratory palatal collapse in patients with obstructive sleep apnoea. Eur Respir J 2018; 51:13993003.01419-2017. [PMID: 29444914 DOI: 10.1183/13993003.01419-2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/29/2017] [Indexed: 12/20/2022]
Abstract
In some individuals with obstructive sleep apnoea (OSA), the palate prolapses into the velopharynx during expiration, limiting airflow through the nose or shunting it out of the mouth. We hypothesised that this phenomenon causes expiratory flow limitation (EFL) and is associated with inspiratory "isolated" palatal collapse. We also wanted to provide a robust noninvasive means to identify this mechanism of obstruction.Using natural sleep endoscopy, 1211 breaths from 22 OSA patients were scored as having or not having palatal prolapse. The patient-level site of collapse (tongue-related, isolated palate, pharyngeal lateral walls and epiglottis) was also characterised. EFL was quantified using expiratory resistance at maximal epiglottic pressure. A noninvasive EFL index (EFLI) was developed to detect the presence of palatal prolapse and EFL using the flow signal alone. In addition, the validity of using nasal pressure was assessed.A cut-off value of EFLI >0.8 detected the presence of palatal prolapse and EFL with an accuracy of >95% and 82%, respectively. The proportion of breaths with palatal prolapse predicted isolated inspiratory palatal collapse with 90% accuracy.This study demonstrates that expiratory palatal prolapse can be quantified noninvasively, is associated with EFL and predicts the presence of inspiratory isolated palatal collapse.
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Affiliation(s)
- Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - 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
| | - Melania Marques
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.,Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Pedro R Genta
- Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Luigi Taranto-Montemurro
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ludovico Messineo
- 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
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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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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58
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Cori JM, O'Donoghue FJ, Jordan AS. Sleeping tongue: current perspectives of genioglossus control in healthy individuals and patients with obstructive sleep apnea. Nat Sci Sleep 2018; 10:169-179. [PMID: 29942169 PMCID: PMC6007201 DOI: 10.2147/nss.s143296] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The focus of this review was on the genioglossus (GG) muscle and its role in maintaining upper airway patency in both healthy individuals and obstructive sleep apnea (OSA) patients. This review provided an overview of GG anatomy and GG control and function during both wakefulness and sleep in healthy individuals and in those with OSA. We reviewed evidence for the role of the GG in OSA pathogenesis and also highlighted abnormalities in GG morphology, responsiveness, tissue movement patterns and neurogenic control that may contribute to or result from OSA. We summarized the different methods for improving GG function and/or activity in OSA and their efficacy. In addition, we discussed the possibility that assessing the synergistic activation of multiple upper airway dilator muscles may provide greater insight into upper airway function and OSA pathogenesis, rather than assessing the GG in isolation.
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Affiliation(s)
- Jennifer M Cori
- Department of Respiratory and Sleep Medicine, Institute for Breathing and Sleep, Austin Hospital, Heidelberg, VIC, Australia
| | - Fergal J O'Donoghue
- Department of Respiratory and Sleep Medicine, Institute for Breathing and Sleep, Austin Hospital, Heidelberg, VIC, Australia
| | - Amy S Jordan
- Department of Psychology, Melbourne School of Psychological Sciences, University of Melbourne, Parkville, VIC, Australia
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59
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Kubin L, Mann GL. Hypoglossal motoneurons are endogenously activated by serotonin during the active period of circadian cycle. Respir Physiol Neurobiol 2017; 248:17-24. [PMID: 29129751 DOI: 10.1016/j.resp.2017.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/01/2017] [Accepted: 11/05/2017] [Indexed: 12/27/2022]
Abstract
In obstructive sleep apnea patients, contraction of lingual muscles protects the pharyngeal airway from collapse. Hypoglossal (XII) motoneurons innervate the muscles of the tongue and are themselves under wake-related excitatory drives, including that mediated by serotonin (5-HT). Estimates of endogenous 5-HT activation vary among different studies. We tested whether endogenous drive mediated by 5-HT is present in rat XII motoneurons when measured during the active period of the circadian cycle. We monitored sleep-wake states and lingual and nuchal electromyograms (EMGs) while perfusing the XII nucleus with a vehicle or a 5-HT2 receptor antagonist (mianserin, 0.2mM) at the active period onset. EMG levels were measured during each behavioral state and normalized by the mean EMG activity during wakefulness at 4-7am. Wake-related lingual EMG was significantly lower during mianserin perfusion than with the vehicle (53.0±9.7% vs. 84.5±8.7%; p=0.002). Mianserin had no effect on nuchal EMG or sleep-wake behavior. Thus, rat XII motoneurons receive endogenous serotonergic activation during wakefulness when measured during the dark period. This indicates that XII motoneuronal activity is enhanced by 5-HT output during the active period of the circadian cycle.
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Affiliation(s)
- Leszek Kubin
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104-6046, USA.
| | - Graziella L Mann
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104-6046, USA
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60
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Younes M. Fifty Years of Physiology in Obstructive Sleep Apnea. Am J Respir Crit Care Med 2017; 196:954-957. [DOI: 10.1164/rccm.201705-1044ed] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Magdy Younes
- Department of MedicineUniversity of ManitobaWinnipeg, Manitoba, Canada
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61
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Burns DP, Rowland J, Canavan L, Murphy KH, Brannock M, O'Malley D, O'Halloran KD, Edge D. Restoration of pharyngeal dilator muscle force in dystrophin-deficient (mdx) mice following co-treatment with neutralizing interleukin-6 receptor antibodies and urocortin 2. Exp Physiol 2017; 102:1177-1193. [PMID: 28665499 DOI: 10.1113/ep086232] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 06/19/2017] [Indexed: 12/26/2022]
Abstract
NEW FINDINGS What is the central question of this study? We previously reported impaired upper airway dilator muscle function in the mdx mouse model of Duchenne muscular dystrophy (DMD). Our aim was to assess the effect of blocking interleukin-6 receptor signalling and stimulating corticotrophin-releasing factor receptor 2 signalling on mdx sternohyoid muscle structure and function. What is the main finding and its importance? The interventional treatment had a positive inotropic effect on sternohyoid muscle force, restoring mechanical work and power to wild-type values, reduced myofibre central nucleation and preserved the myosin heavy chain type IIb fibre complement of mdx sternohyoid muscle. These data might have implications for development of pharmacotherapies for DMD with relevance to respiratory muscle performance. The mdx mouse model of Duchenne muscular dystrophy shows evidence of impaired pharyngeal dilator muscle function. We hypothesized that inflammatory and stress-related factors are implicated in airway dilator muscle dysfunction. Six-week-old mdx (n = 26) and wild-type (WT; n = 26) mice received either saline (0.9% w/v) or a co-administration of neutralizing interleukin-6 receptor antibodies (0.2 mg kg-1 ) and corticotrophin-releasing factor receptor 2 agonist (urocortin 2; 30 μg kg-1 ) over 2 weeks. Sternohyoid muscle isometric and isotonic contractile function was examined ex vivo. Muscle fibre centronucleation and muscle cellular infiltration, collagen content, fibre-type distribution and fibre cross-sectional area were determined by histology and immunofluorescence. Muscle chemokine content was examined by use of a multiplex assay. Sternohyoid peak specific force at 100 Hz was significantly reduced in mdx compared with WT. Drug treatment completely restored force in mdx sternohyoid to WT levels. The percentage of centrally nucleated muscle fibres was significantly increased in mdx, and this was partly ameliorated after drug treatment. The areal density of infiltrates and collagen content were significantly increased in mdx sternohyoid; both indices were unaffected by drug treatment. The abundance of myosin heavy chain type IIb fibres was significantly decreased in mdx sternohyoid; drug treatment preserved myosin heavy chain type IIb complement in mdx muscle. The chemokines macrophage inflammatory protein 2, interferon-γ-induced protein 10 and macrophage inflammatory protein 3α were significantly increased in mdx sternohyoid compared with WT. Drug treatment significantly increased chemokine expression in mdx but not WT sternohyoid. Recovery of contractile function was impressive in our study, with implications for Duchenne muscular dystrophy. The precise molecular mechanisms by which the drug treatment exerts an inotropic effect on mdx sternohyoid muscle remain to be elucidated.
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Affiliation(s)
- David P Burns
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Jane Rowland
- Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Leonie Canavan
- Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Kevin H Murphy
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Molly Brannock
- Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Dervla O'Malley
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Deirdre Edge
- Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, Dublin, Ireland
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62
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O'Halloran KD, Lewis P. Respiratory muscle dysfunction in animal models of hypoxic disease: antioxidant therapy goes from strength to strength. HYPOXIA 2017; 5:75-84. [PMID: 28770235 PMCID: PMC5529115 DOI: 10.2147/hp.s141283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The striated muscles of breathing play a critical role in respiratory homeostasis governing blood oxygenation and pH regulation. Upper airway dilator and thoracic pump muscles retain a remarkable capacity for plasticity throughout life, both in health and disease states. Hypoxia, whatever the cause, is a potent driver of respiratory muscle remodeling with evidence of adaptive and maladaptive outcomes for system performance. The pattern, duration, and intensity of hypoxia are key determinants of respiratory muscle structural-, metabolic-, and functional responses and adaptation. Age and sex also influence respiratory muscle tolerance of hypoxia. Redox stress emerges as the principal protagonist driving respiratory muscle malady in rodent models of hypoxic disease. There is a growing body of evidence demonstrating that antioxidant intervention alleviates hypoxia-induced respiratory muscle dysfunction, and that N-acetyl cysteine, approved for use in humans, is highly effective in preventing hypoxia-induced respiratory muscle weakness and fatigue. We posit that oxygen homeostasis is a key driver of respiratory muscle form and function. Hypoxic stress is likely a major contributor to respiratory muscle malaise in diseases of the lungs and respiratory control network. Animal studies provide an evidence base in strong support of the need to explore adjunctive antioxidant therapies for muscle dysfunction in human respiratory disease.
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Affiliation(s)
- Ken D O'Halloran
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Philip Lewis
- Institute and Policlinic for Occupational Medicine, Environmental Medicine and Preventative Research, University Hospital of Cologne, Germany
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63
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Horner RL, Grace KP, Wellman A. A resource of potential drug targets and strategic decision-making for obstructive sleep apnoea pharmacotherapy. Respirology 2017; 22:861-873. [PMID: 28544082 PMCID: PMC5515492 DOI: 10.1111/resp.13079] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/06/2017] [Accepted: 04/12/2017] [Indexed: 12/11/2022]
Abstract
There is currently no pharmacotherapy for obstructive sleep apnoea (OSA) but there is no principled a priori reason why there should not be one. This review identifies a rational decision‐making strategy with the necessary logical underpinnings that any reasonable approach would be expected to navigate to develop a viable pharmacotherapy for OSA. The process first involves phenotyping an individual to quantify and characterize the critical predisposing factor(s) to their OSA pathogenesis and identify, a priori, if the patient is likely to benefit from a pharmacotherapy that targets those factors. We then identify rational strategies to manipulate those critical predisposing factor(s), and the barriers that have to be overcome for success of any OSA pharmacotherapy. A new analysis then identifies candidate drug targets to manipulate the upper airway motor circuitry for OSA pharmacotherapy. The first conclusion is that there are two general pharmacological approaches for OSA treatment that are of the most potential benefit and are practically realistic, one being fairly intuitive but the second perhaps less so. The second conclusion is that after identifying the critical physiological obstacles to OSA pharmacotherapy, there are current therapeutic targets of high interest for future development. The final analysis provides a tabulated resource of ‘druggable’ targets that are relatively restricted to the circuitry controlling the upper airway musculature, with these candidate targets being of high priority for screening and further study. We also emphasize that a pharmacotherapy may not cure OSAper se, but may still be a useful adjunct to improve the effectiveness of, and adherence to, other treatment mainstays.
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Affiliation(s)
- Richard L Horner
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Kevin P Grace
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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64
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Azarbarzin A, Sands SA, Taranto-Montemurro L, Oliveira Marques MD, Genta PR, Edwards BA, Butler J, White DP, Wellman A. Estimation of Pharyngeal Collapsibility During Sleep by Peak Inspiratory Airflow. Sleep 2017; 40:2666705. [PMID: 28364460 PMCID: PMC6084748 DOI: 10.1093/sleep/zsw005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Objectives Pharyngeal critical closing pressure (Pcrit) or collapsibility is a major determinant of obstructive sleep apnea (OSA) and may be used to predict the success/failure of non-continuous positive airway pressure (CPAP) therapies. Since its assessment involves overnight manipulation of CPAP, we sought to validate the peak inspiratory flow during natural sleep (without CPAP) as a simple surrogate measurement of collapsibility. Methods Fourteen patients with OSA attended overnight polysomnography with pneumotachograph airflow. The middle third of the night (non-rapid eye movement sleep [NREM]) was dedicated to assessing Pcrit in passive and active states via abrupt and gradual CPAP pressure drops, respectively. Pcrit is the extrapolated CPAP pressure at which flow is zero. Peak and mid-inspiratory flow off CPAP was obtained from all breaths during sleep (excluding arousal) and compared with Pcrit. Results Active Pcrit, measured during NREM sleep, was strongly correlated with both peak and mid-inspiratory flow during NREM sleep (r = -0.71, p < .005 and r = -0.64, p < .05, respectively), indicating that active pharyngeal collapsibility can be reliably estimated from simple airflow measurements during polysomnography. However, there was no significant relationship between passive Pcrit, measured during NREM sleep, and peak or mid-inspiratory flow obtained from NREM sleep. Flow measurements during REM sleep were not significantly associated with active or passive Pcrit. Conclusions Our study demonstrates the feasibility of estimating active Pcrit using flow measurements in patients with OSA. This method may enable clinicians to estimate pharyngeal collapsibility without sophisticated equipment and potentially aid in the selection of patients for non- positive airway pressure therapies.
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Affiliation(s)
- Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Scott A Sands
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
- Department of Allergy Immunology and Respiratory Medicine and Central Clinical School, The Alfred and Monash University, Melbourne, Australia
| | - Luigi Taranto-Montemurro
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Melania D Oliveira Marques
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
- Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Pedro R Genta
- Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Bradley A Edwards
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
- 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
| | - James Butler
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - David P White
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
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65
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O'Halloran KD, Lewis P, McDonald F. Sex, stress and sleep apnoea: Decreased susceptibility to upper airway muscle dysfunction following intermittent hypoxia in females. Respir Physiol Neurobiol 2016; 245:76-82. [PMID: 27884793 DOI: 10.1016/j.resp.2016.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/19/2016] [Accepted: 11/20/2016] [Indexed: 12/21/2022]
Abstract
Obstructive sleep apnoea syndrome (OSAS) is a devastating respiratory control disorder more common in men than women. The reasons for the sex difference in prevalence are multifactorial, but are partly attributable to protective effects of oestrogen. Indeed, OSAS prevalence increases in post-menopausal women. OSAS is characterized by repeated occlusions of the pharyngeal airway during sleep. Dysfunction of the upper airway muscles controlling airway calibre and collapsibility is implicated in the pathophysiology of OSAS, and sex differences in the neuro-mechanical control of upper airway patency are described. It is widely recognized that chronic intermittent hypoxia (CIH), a cardinal feature of OSAS due to recurrent apnoea, drives many of the morbid consequences characteristic of the disorder. In rodents, exposure to CIH-related redox stress causes upper airway muscle weakness and fatigue, associated with mitochondrial dysfunction. Of interest, in adults, there is female resilience to CIH-induced muscle dysfunction. Conversely, exposure to CIH in early life, results in upper airway muscle weakness equivalent between the two sexes at 3 and 6 weeks of age. Ovariectomy exacerbates the deleterious effects of exposure to CIH in adult female upper airway muscle, an effect partially restored by oestrogen replacement therapy. Intriguingly, female advantage intrinsic to upper airway muscle exists with evidence of substantially greater loss of performance in male muscle during acute exposure to severe hypoxic stress. Sex differences in upper airway muscle physiology may have relevance to human OSAS. The oestrogen-oestrogen receptor α axis represents a potential therapeutic target in OSAS, particularly in post-menopausal women.
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Affiliation(s)
- Ken D O'Halloran
- Department of Physiology, University College Cork, Cork, Ireland.
| | - Philip Lewis
- Department of Physiology, University College Cork, Cork, Ireland; Institute and Policlinic for Occupational Medicine, Environmental Medicine and Preventative Research, University of Cologne, Germany
| | - Fiona McDonald
- Physiology, School of Medicine, University College Dublin, Dublin, Ireland; School of Clinical Sciences, Bristol University, Bristol, United Kingdom
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66
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Bayat M, Shariati M, Rakhshan V, Abbasi M, Fateh A, Sobouti F, Davoudmanesh Z. Cephalometric risk factors of obstructive sleep apnea. Cranio 2016; 35:321-326. [DOI: 10.1080/08869634.2016.1239850] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Mohamad Bayat
- Craniomaxillofacial Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahsa Shariati
- Craniomaxillofacial Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Vahid Rakhshan
- Research Council, Iranian Center for Tissue Engineering and Graft Research, Tehran University of Medical Sciences, Tehran, Iran
- Department of Dental Anatomy and Morphology, Dental Branch, Islamic Azad University, Tehran, Iran
| | - Mohsen Abbasi
- Craniomaxillofacial Research Center, Dental Branch, Islamic Azad University, Tehran, Iran
| | - Ali Fateh
- Craniomaxillofacial Research Center, Dental Branch, Islamic Azad University, Tehran, Iran
| | - Farhad Sobouti
- Department of Orthodontics, Faculty of Dental, Mazandaran University of Medical Sciences, Sari, Iran
| | - Zeinab Davoudmanesh
- Craniomaxillofacial Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
- Craniomaxillofacial Research Center, Dental Branch, Islamic Azad University, Tehran, Iran
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Taranto-Montemurro L, Sands SA, Edwards BA, Azarbarzin A, Marques M, de Melo C, Eckert DJ, White DP, Wellman A. Desipramine improves upper airway collapsibility and reduces OSA severity in patients with minimal muscle compensation. Eur Respir J 2016; 48:1340-1350. [PMID: 27799387 DOI: 10.1183/13993003.00823-2016] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/19/2016] [Indexed: 11/05/2022]
Abstract
We recently demonstrated that desipramine reduces the sleep-related loss of upper airway dilator muscle activity and reduces pharyngeal collapsibility in healthy humans without obstructive sleep apnoea (OSA). The aim of the present physiological study was to determine the effects of desipramine on upper airway collapsibility and apnoea-hypopnea index (AHI) in OSA patients.A placebo-controlled, double-blind, randomised crossover trial in 14 OSA patients was performed. Participants received treatment or placebo in randomised order before sleep. Pharyngeal collapsibility (critical collapsing pressure of the upper airway (Pcrit)) and ventilation under both passive (V'0,passive) and active (V'0,active) upper airway muscle conditions were evaluated with continuous positive airway pressure (CPAP) manipulation. AHI was quantified off CPAP.Desipramine reduced active Pcrit (median (interquartile range) -5.2 (4.3) cmH2O on desipramine versus -1.9 (2.7) cmH2O on placebo; p=0.049) but not passive Pcrit (-2.2 (3.4) versus -0.7 (2.1) cmH2O; p=0.135). A greater reduction in AHI occurred in those with minimal muscle compensation (defined as V'0,active-V'0,passive) on placebo (r=0.71, p=0.009). The reduction in AHI was driven by the improvement in muscle compensation (r=0.72, p=0.009).In OSA patients, noradrenergic stimulation with desipramine improves pharyngeal collapsibility and may be an effective treatment in patients with minimal upper airway muscle compensation.
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Affiliation(s)
- Luigi Taranto-Montemurro
- Division of Sleep and Circadian Disorders, Depts of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Scott A Sands
- Division of Sleep and Circadian Disorders, Depts of Medicine and Neurology, Brigham & Women's Hospital & 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, Depts of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA, USA.,Sleep and Circadian Medicine Laboratory, Department of Physiology, Monash University, Melbourne, Australia.,School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, Australia
| | - Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Depts of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Melania Marques
- Division of Sleep and Circadian Disorders, Depts of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Camila de Melo
- Division of Sleep and Circadian Disorders, Depts of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Danny J Eckert
- Neuroscience Research Australia (NeuRA) and the University of New South Wales, Randwick, Australia
| | - David P White
- Division of Sleep and Circadian Disorders, Depts of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA, USA
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Depts of Medicine and Neurology, Brigham & Women's Hospital & Harvard Medical School, Boston, MA, USA
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O’Halloran KD. Chronic intermittent hypoxia creates the perfect storm with calamitous consequences for respiratory control. Respir Physiol Neurobiol 2016; 226:63-7. [DOI: 10.1016/j.resp.2015.10.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 10/20/2015] [Accepted: 10/23/2015] [Indexed: 11/27/2022]
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Davoudmanesh Z, Bayat M, Abbasi M, Rakhshan V, Shariati M. Cephalometric risk factors associated with myocardial infarction in patients suffering from obstructive sleep apnea: A pilot case-control study. Cranio 2016; 35:15-18. [PMID: 27095068 DOI: 10.1080/08869634.2016.1169615] [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: 01/03/2023]
Abstract
INTRODUCTION Obstructive sleep apnea (OSA) and its craniofacial anatomic risk factors might play a role in several cardiovascular diseases, including myocardial infarction (MI). However, there are no data about cephalometric findings among OSA patients with MI. METHODS In this pilot case-control study, about 2000 individuals referred to the sleep center were evaluated according to apnea - hypopnea index (AHI) and other inclusion criteria. Included were 62 OSA male patients (AHI > 10), of whom 6 had an MI history. In both control (n = 56) and MI groups (n = 6), 18 cephalometric parameters were traced. Data were analyzed using independent samples t-test. RESULTS Compared with control OSA patients, OSA patients with MI showed a significantly larger tongue length (p = 0.015). The other cephalometric variables were not significantly different between the two groups. CONCLUSION An elongated tongue might be considered a risk factor for MI in OSA patients. The role of other variables remains inconclusive and open to investigation with larger samples (determined based on pilot studies such as this report) collected in longitudinal fashion.
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Affiliation(s)
- Zeinab Davoudmanesh
- a Craniomaxillofacial Research Center, Shariati Hospital , Tehran University of Medical Sciences , Tehran , Iran.,b Craniomaxillofacial Surgery Research Center , Dental Branch, Islamic Azad University , Tehran , Iran
| | - Mohamad Bayat
- a Craniomaxillofacial Research Center, Shariati Hospital , Tehran University of Medical Sciences , Tehran , Iran.,c Dental Faculty, Department of Oral and Maxillofacial Surgery , Tehran University of Medical Sciences , Tehran , Iran
| | - Mohsen Abbasi
- a Craniomaxillofacial Research Center, Shariati Hospital , Tehran University of Medical Sciences , Tehran , Iran.,c Dental Faculty, Department of Oral and Maxillofacial Surgery , Tehran University of Medical Sciences , Tehran , Iran
| | - Vahid Rakhshan
- d Iranian Tissue Engineering and Graft Research Center , Tehran University of Medical Sciences , Tehran , Iran.,e Department of Dental Anatomy and Morphology , Dental Branch, Islamic Azad University , Tehran , Iran
| | - Mahsa Shariati
- a Craniomaxillofacial Research Center, Shariati Hospital , Tehran University of Medical Sciences , Tehran , Iran
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MacKay CM, Skow RJ, Tymko MM, Boulet LM, Davenport MH, Steinback CD, Ainslie PN, Lemieux CCM, Day TA. Central respiratory chemosensitivity and cerebrovascular CO2 reactivity: a rebreathing demonstration illustrating integrative human physiology. ADVANCES IN PHYSIOLOGY EDUCATION 2016; 40:79-92. [PMID: 26873894 DOI: 10.1152/advan.00048.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
One of the most effective ways of engaging students of physiology and medicine is through laboratory demonstrations and case studies that combine 1) the use of equipment, 2) problem solving, 3) visual representations, and 4) manipulation and interpretation of data. Depending on the measurements made and the type of test, laboratory demonstrations have the added benefit of being able to show multiple organ system integration. Many research techniques can also serve as effective demonstrations of integrative human physiology. The "Duffin" hyperoxic rebreathing test is often used in research settings as a test of central respiratory chemosensitivity and cerebrovascular reactivity to CO2. We aimed to demonstrate the utility of the hyperoxic rebreathing test for both respiratory and cerebrovascular responses to increases in CO2 and illustrate the integration of the respiratory and cerebrovascular systems. In the present article, methods such as spirometry, respiratory gas analysis, and transcranial Doppler ultrasound are described, and raw data traces can be adopted for discussion in a tutorial setting. If educators have these instruments available, instructions on how to carry out the test are provided so students can collect their own data. In either case, data analysis and quantification are discussed, including principles of linear regression, calculation of slope, the coefficient of determination (R(2)), and differences between plotting absolute versus normalized data. Using the hyperoxic rebreathing test as a demonstration of the complex interaction and integration between the respiratory and cerebrovascular systems provides senior undergraduate, graduate, and medical students with an advanced understanding of the integrative nature of human physiology.
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Affiliation(s)
- Christina M MacKay
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada; Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada; and
| | - Rachel J Skow
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada; Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada; and
| | - Michael M Tymko
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada; School of Health and Exercise Sciences, Faculty of Health and Social Development, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Lindsey M Boulet
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada; School of Health and Exercise Sciences, Faculty of Health and Social Development, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Margie H Davenport
- Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada; and
| | - Craig D Steinback
- Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada; and
| | - Philip N Ainslie
- School of Health and Exercise Sciences, Faculty of Health and Social Development, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Chantelle C M Lemieux
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Trevor A Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada;
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Garcia AJ, Zanella S, Dashevskiy T, Khan SA, Khuu MA, Prabhakar NR, Ramirez JM. Chronic Intermittent Hypoxia Alters Local Respiratory Circuit Function at the Level of the preBötzinger Complex. Front Neurosci 2016; 10:4. [PMID: 26869872 PMCID: PMC4740384 DOI: 10.3389/fnins.2016.00004] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 01/07/2016] [Indexed: 01/08/2023] Open
Abstract
Chronic intermittent hypoxia (CIH) is a common state experienced in several breathing disorders, including obstructive sleep apnea (OSA) and apneas of prematurity. Unraveling how CIH affects the CNS, and in turn how the CNS contributes to apneas is perhaps the most challenging task. The preBötzinger complex (preBötC) is a pre-motor respiratory network critical for inspiratory rhythm generation. Here, we test the hypothesis that CIH increases irregular output from the isolated preBötC, which can be mitigated by antioxidant treatment. Electrophysiological recordings from brainstem slices revealed that CIH enhanced burst-to-burst irregularity in period and/or amplitude. Irregularities represented a change in individual fidelity among preBötC neurons, and changed transmission from preBötC to the hypoglossal motor nucleus (XIIn), which resulted in increased transmission failure to XIIn. CIH increased the degree of lipid peroxidation in the preBötC and treatment with the antioxidant, 5,10,15,20-Tetrakis (1-methylpyridinium-4-yl)-21H,23H-porphyrin manganese(III) pentachloride (MnTMPyP), reduced CIH-mediated irregularities on the network rhythm and improved transmission of preBötC to the XIIn. These findings suggest that CIH promotes a pro-oxidant state that destabilizes rhythmogenesis originating from the preBötC and changes the local rhythm generating circuit which in turn, can lead to intermittent transmission failure to the XIIn. We propose that these CIH-mediated effects represent a part of the central mechanism that may perpetuate apneas and respiratory instability, which are hallmark traits in several dysautonomic conditions.
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Affiliation(s)
- Alfredo J Garcia
- Center for Integrative Brain Research, Seattle Children's Research Institute Seattle, WA, USA
| | - Sebastien Zanella
- Center for Integrative Brain Research, Seattle Children's Research Institute Seattle, WA, USA
| | - Tatiana Dashevskiy
- Center for Integrative Brain Research, Seattle Children's Research Institute Seattle, WA, USA
| | - Shakil A Khan
- Institute for Integrative Physiology, The University of Chicago Chicago, IL, USA
| | - Maggie A Khuu
- Center for Integrative Brain Research, Seattle Children's Research Institute Seattle, WA, USA
| | - Nanduri R Prabhakar
- Institute for Integrative Physiology, The University of Chicago Chicago, IL, USA
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research InstituteSeattle, WA, USA; Departments of Neurological Surgery and Pediatrics, University of WashingtonSeattle, WA, USA
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Abstract
PURPOSE OF REVIEW Perioperative opioid-based pain management of patients suffering from obstructive sleep apnea (OSA) may present challenges because of concerns over severe ventilatory compromise. The interaction between intermittent hypoxia, sleep fragmentation, pain, and opioid responses in OSA, is complex and warrants a special focus of perioperative outcomes research. RECENT FINDINGS Life-threatening opioid-related respiratory events are rare. Epidemiologic evidence suggests that OSA together with other serious renal and heart disease, is among those conditions predisposing patients for opioid-induced ventilatory impairment (OIVI) in the postoperative period. Both intermittent hypoxia and sleep fragmentation, two distinct components of OSA, enhance pain. Intermittent hypoxia may also potentiate opioid analgesic effects. Activation of major inflammatory pathways may be responsible for the effects of sleep disruption and intermittent hypoxia on pain and opioid analgesia. Recent experimental evidence supports that these, seemingly contrasting, phenotypes of pain-increasing and opioid-enhancing effects of intermittent hypoxia, are not mutually exclusive. Although the effect of intermittent hypoxia on OIVI has not been elucidated, opioids worsen postoperative sleep-disordered breathing in OSA patients. A subset of these patients, characterized by decreased chemoreflex responsiveness and high arousal thresholds, might be at higher risk for OIVI. SUMMARY OSA may complicate opioid-based perioperative management of pain by altering both pain processing and sensitivity to opioid effect.
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Affiliation(s)
- Karen K. Lam
- Department of Anaesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Samuel Kunder
- Department of Anaesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Jean Wong
- Department of Anaesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Anthony G. Doufas
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Frances Chung
- Department of Anaesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
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Younes M, Hanly PJ. Immediate postarousal sleep dynamics: an important determinant of sleep stability in obstructive sleep apnea. J Appl Physiol (1985) 2015; 120:801-8. [PMID: 26718786 DOI: 10.1152/japplphysiol.00880.2015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/29/2015] [Indexed: 01/08/2023] Open
Abstract
Arousability from sleep is increasingly recognized as an important determinant of the clinical spectrum of sleep disordered breathing (SDB). Patients with SDB display a wide range of arousability. The reason for these differences is not known. We hypothesized that differences in the speed with which sleep deepens following arousals/awakenings (postarousal sleep dynamics) is a major determinant of these differences in arousability in patients with SDB. We analyzed 40 preexisting clinical polysomnography records from patients with a range of SDB severity (apnea-hypopnea index 5-135/h). Sleep depth was determined every 3 s using the odds ratio product (ORP) method, a continuous index of sleep depth (0 = deep sleep, 2.5 = full wakefulness) that correlates strongly (r = 0.98) with arousability (Younes M, Ostrowski M, Soiferman M, Younes H, Younes M, Raneri J, and Hanly P. Sleep 38: 641-654, 2015). Time course of ORP was determined from end of arousal until the next arousal. All arousals were analyzed (142 ± 65/polysomnogram). ORP increased from 0.58 ± 0.32 during sleep to 1.67 ± 0.35 during arousals. ORP immediately (first 9 s) following arousals/awakenings (ORP-9) ranged from 0.21(very deep sleep) to 1.71 (highly arousable state) in different patients. In patients with high ORP-9, sleep deepened slowly (over minutes) beyond 9 s but only if no arousals/awakenings recurred. ORP-9 correlated strongly with average non-rapid eye movement sleep depth (r = 0.87, P < 2E-13), the arousal/awakening index (r = 0.68, P < 5E-6), and with the apnea-hypopnea index (r = 0.60, P < 0.001). ORP-9 was consistent within each patient and did not change on continuous positive airway pressure despite marked improvement in sleep architecture. We conclude that postarousal sleep dynamics are highly variable among patients with sleep-disordered breathing and largely determine average sleep depth and continuity.
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Affiliation(s)
- Magdy Younes
- Sleep Disorders Centre, University of Manitoba, Winnipeg, and Sleep Center, Foothills Medical Centre, University of Calgary, Canada
| | - Patrick J Hanly
- Sleep Center, Foothills Medical Centre, University of Calgary, Canada
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Five-Year Subjective Outcomes of Obstructive Sleep Apnea Surgery: A Multiinstitutional Study. Clin Exp Otorhinolaryngol 2015; 8:370-5. [PMID: 26622956 PMCID: PMC4661253 DOI: 10.3342/ceo.2015.8.4.370] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 10/20/2014] [Accepted: 10/20/2014] [Indexed: 11/12/2022] Open
Abstract
Objectives To evaluate the effect of obstructive sleep apnea (OSA) surgery on long-term (5-year) subjective outcomes, including sleep disordered breathing (SDB) symptoms and other complications, in patients with OSA. Methods We enrolled patients who underwent diagnostic polysomnography for OSA between January 2006 and December 2006 in ten hospitals. Patients either were treated for OSA or were not treated for OSA. All patients completed a brief telephone survey regarding their SDB signs and symptoms (e.g., snoring, apnea, nocturnal arousals, and daytime sleepiness), positive airway pressure (PAP) compliance, and any adverse effects of either the surgery or PAP. A positive subjective outcome for either surgery or no treatment was taken to be the alleviation of apnea, defined as a ≥50% increase in score. A positive subjective outcome (compliance) for PAP was defined as a PAP usage of ≥4 hours per night and ≥5 days per week. Results A total of 229 patients were included in this study. Patients were divided into three groups: a surgery group (n=87), a PAP group (n=68), and a control (untreated) group (n=74). The surgery group exhibited significant improvement in all SDB symptoms compared with the control group. The long-term subjective outcomes of the surgery (52.9%) and PAP (54.4%) groups were significantly better than those of the control group (25.0%). The subjective outcome of the surgery group was not significantly different from that of the PAP group. The overall surgical complication rate was 23.0% (20 of 87) in the surgery group, and 55.0% (22 of 40) of all patients with PAP experienced adverse effects. Conclusion The extent of SDB symptoms was consistently improved in patients with OSA at 5 years postsurgery. Information about the potential long-term subjective outcomes should be provided to patients when considering surgery.
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Gross NJ, Funk J, Pache M, van der List M, Laubmann-Volz A, Sorichter S, Lagrèze WA. [Prevalence of glaucoma in obstructive sleep apnea]. Ophthalmologe 2015; 112:580-4. [PMID: 25585796 DOI: 10.1007/s00347-014-3146-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND A causal relationship between glaucoma and obstructive sleep apnea has been postulated in several clinical studies but also refuted by others. The aim of this study was to determine the prevalence of glaucoma in a cohort of patients with well-established obstructive sleep apnea in comparison to the published data on this topic. METHODS A total of 100 consecutive patients (male:female 80:20, mean age 59 ± 11 years SD) with polysomnographically established obstructive sleep apnea underwent an ophthalmological examination including tonometry, static perimetry and dilated fundus photography. Visual fields and fundus photographs of the patients were classified as glaucomatous or non-glaucomatous by two independent examiners. RESULTS The prevalence of glaucoma in the study patients was 2 % which corresponded to the published prevalence of glaucoma in the normal population. Intraocular pressure did not correlate with the respiratory index, body mass index or sex. CONCLUSION The data from this study shed doubt on a causal relationship between obstructive sleep apnea and glaucoma.
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Affiliation(s)
- N J Gross
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg im Breisgau, Deutschland,
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Ogna A, Forni Ogna V, Mihalache A, Pruijm M, Halabi G, Phan O, Cornette F, Bassi I, Haba Rubio J, Burnier M, Heinzer R. Obstructive Sleep Apnea Severity and Overnight Body Fluid Shift before and after Hemodialysis. Clin J Am Soc Nephrol 2015; 10:1002-10. [PMID: 25862778 PMCID: PMC4455216 DOI: 10.2215/cjn.08760914] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 02/19/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Obstructive sleep apnea is associated with significantly increased cardiovascular morbidity and mortality. Fluid overload may promote obstructive sleep apnea in patients with ESRD through an overnight fluid shift from the legs to the neck soft tissues. Body fluid shift and severity of obstructive sleep apnea before and after hemodialysis were compared in patients with ESRD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Seventeen patients with hemodialysis and moderate to severe obstructive sleep apnea were included. Polysomnographies were performed the night before and after hemodialysis to assess obstructive sleep apnea, and bioimpedance was used to measure fluid overload and leg fluid volume. RESULTS The mean overnight rostral fluid shift was 1.27±0.41 L prehemodialysis; it correlated positively with fluid overload volume (r=0.39; P=0.02) and was significantly lower posthemodialysis (0.78±0.38 L; P<0.001). There was no significant difference in the mean obstructive apnea-hypopnea index before and after hemodialysis (46.8±22.0 versus 42.1±18.6 per hour; P=0.21), but obstructive apnea-hypopnea index was significantly lower posthemodialysis (-10.1±10.8 per hour) in the group of 12 patients, with a concomitant reduction of fluid overload compared with participants without change in fluid overload (obstructive apnea-hypopnea index +8.2±16.1 per hour; P<0.01). A lower fluid overload after hemodialysis was significantly correlated (r=0.49; P=0.04) with a lower obstructive apnea-hypopnea index. Fluid overload-assessed by bioimpedance-was the best predictor of the change in obstructive apnea-hypopnea index observed after hemodialysis (standardized r=-0.68; P=0.01) in multivariate regression analysis. CONCLUSIONS Fluid overload influences overnight rostral fluid shift and obstructive sleep apnea severity in patients with ESRD undergoing intermittent hemodialysis. Although no benefit of hemodialysis on obstructive sleep apnea severity was observed in the whole group, the change in obstructive apnea-hypopnea index was significantly correlated with the change in fluid overload after hemodialysis. Moreover, the subgroup with lower fluid overload posthemodialysis showed a significantly lower obstructive sleep apnea severity, which provides a strong incentive to further study whether optimizing fluid status in patients with obstructive sleep apnea and ESRD will improve the obstructive apnea-hypopnea index.
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Affiliation(s)
- Adam Ogna
- Center for Investigation and Research in Sleep, Service of Respiratory Medicine, and
| | - Valentina Forni Ogna
- Service of Nephrology and Hypertension, University Hospital of Lausanne, Lausanne, Switzerland
| | - Alexandra Mihalache
- Center for Investigation and Research in Sleep, Service of Respiratory Medicine, and
| | - Menno Pruijm
- Service of Nephrology and Hypertension, University Hospital of Lausanne, Lausanne, Switzerland
| | - Georges Halabi
- Hemodialysis Unit, Northern Vaud Hospitals, Yverdon, Switzerland; and
| | - Olivier Phan
- Hemodialysis Unit, Intercantonal Hospital, Payerne, Switzerland
| | | | - Isabelle Bassi
- Service of Nephrology and Hypertension, University Hospital of Lausanne, Lausanne, Switzerland
| | | | - Michel Burnier
- Service of Nephrology and Hypertension, University Hospital of Lausanne, Lausanne, Switzerland
| | - Raphaël Heinzer
- Center for Investigation and Research in Sleep, Service of Respiratory Medicine, and
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Younes M. CrossTalk proposal: elevated loop gain is a consequence of obstructive sleep apnoea. J Physiol 2015; 592:2899-901. [PMID: 25027956 DOI: 10.1113/jphysiol.2014.271833] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Magdy Younes
- Department of Internal Medicine, University of Manitoba, 1001 Wellington Crescent, Winnipeg, MB, Canada, R3M 0A7
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Jordan AS, Cori JM, Dawson A, Nicholas CL, O'Donoghue FJ, Catcheside PG, Eckert DJ, McEvoy RD, Trinder J. Arousal from sleep does not lead to reduced dilator muscle activity or elevated upper airway resistance on return to sleep in healthy individuals. Sleep 2015; 38:53-9. [PMID: 25325511 DOI: 10.5665/sleep.4324] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 05/23/2014] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES To compare changes in end-tidal CO2, genioglossus muscle activity and upper airway resistance following tone-induced arousal and the return to sleep in healthy individuals with small and large ventilatory responses to arousal. DESIGN Observational study. SETTING Two sleep physiology laboratories. PATIENTS OR PARTICIPANTS 35 men and 25 women with no medical or sleep disorders. INTERVENTIONS Auditory tones to induce 3-s to 15-s cortical arousals from sleep. MEASUREMENTS AND RESULTS During arousal from sleep, subjects with large ventilatory responses to arousal had higher ventilation (by analytical design) and tidal volume, and more marked reductions in the partial pressure of end-tidal CO2 compared to subjects with small ventilatory responses to arousal. However, following the return to sleep, ventilation, genioglossus muscle activity, and upper airway resistance did not differ between high and low ventilatory response groups (Breath 1 on return to sleep: ventilation 6.7±0.4 and 5.5±0.3 L/min, peak genioglossus activity 3.4%±1.0% and 4.8%±1.0% maximum, upper airway resistance 4.7±0.7 and 5.5±1.0 cm H2O/L/s, respectively). Furthermore, dilator muscle activity did not fall below the pre-arousal sleeping level and upper airway resistance did not rise above the pre-arousal sleeping level in either group for 10 breaths following the return to sleep. CONCLUSIONS Regardless of the magnitude of the ventilatory response to arousal from sleep and subsequent reduction in PETCO2, healthy individuals did not develop reduced dilator muscle activity nor increased upper airway resistance, indicative of partial airway collapse, on the return to sleep. These findings challenge the commonly stated notion that arousals predispose to upper airway obstruction.
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Affiliation(s)
- Amy S Jordan
- University of Melbourne, Parkville VIC, Australia: Institute for Breathing and Sleep, Heidelberg VIC, Australia
| | - Jennifer M Cori
- University of Melbourne, Parkville VIC, Australia: Institute for Breathing and Sleep, Heidelberg VIC, Australia
| | - Andrew Dawson
- University of Melbourne, Parkville VIC, Australia: : Institute for Breathing and Sleep, Heidelberg VIC, Australia
| | | | - Fergal J O'Donoghue
- University of Melbourne, Parkville VIC, Australia: Institute for Breathing and Sleep, Heidelberg VIC, Australia
| | - Peter G Catcheside
- Adelaide Institute for Sleep Health, Daw Park, SA, Australia: Flinders University, Bedford Park SA, Australia
| | - Danny J Eckert
- Neuroscience Research Australia (NeuRA) and the University of New South Wales, Randwick NSW, Australia
| | - R Doug McEvoy
- Adelaide Institute for Sleep Health, Daw Park, SA, Australia: Flinders University, Bedford Park SA, Australia
| | - John Trinder
- University of Melbourne, Parkville VIC, Australia
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Khawaja IS, Hashmi A, Ebrahim A, Ullevig C, Shah A, Hurwitz TD. Obstructive Sleep Apnea: An Update for Mental Health Providers. Psychiatr Ann 2015. [DOI: 10.3928/00485713-20150106-05] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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80
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Fung SJ, Chase MH. Postsynaptic inhibition of hypoglossal motoneurons produces atonia of the genioglossal muscle during rapid eye movement sleep. Sleep 2015; 38:139-46. [PMID: 25325470 DOI: 10.5665/sleep.4340] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
STUDY OBJECTIVES Hypoglossal motoneurons were recorded intracellularly to determine whether postsynaptic inhibition or disfacilitation was responsible for atonia of the lingual muscles during rapid eye movement (REM) sleep. DESIGN Intracellular records were obtained of the action potentials and subthreshold membrane potential activity of antidromically identified hypoglossal motoneurons in cats during wakefulness, nonrapid eye movement (NREM) sleep, and REM sleep. A cuff electrode was placed around the hypoglossal nerve to antidromically activate hypoglossal motoneurons. The state-dependent changes in membrane potential, spontaneous discharge, postsynaptic potentials, and rheobase of hypoglossal motoneurons were determined. ANALYSES AND RESULTS During quiet wakefulness and NREM sleep, hypoglossal motoneurons exhibited spontaneous repetitive discharge. In the transition from NREM sleep to REM sleep, repetitive discharge ceased and the membrane potential began to hyperpolarize; maximal hyperpolarization (10.5 mV) persisted throughout REM sleep. During REM sleep there was a significant increase in rheobase, which was accompanied by barrages of large-amplitude inhibitory postsynaptic potentials (IPSPs), which were reversed following the intracellular injection of chloride ions. The latter result indicates that they were mediated by glycine; IPSPs were not present during wakefulness or NREM sleep. CONCLUSIONS We conclude that hypoglossal motoneurons are postsynaptically inhibited during naturally occurring REM sleep; no evidence of disfacilitation was observed. The data also indicate that glycine receptor-mediated postsynaptic inhibition of hypoglossal motoneurons is crucial in promoting atonia of the lingual muscles during REM sleep.
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Affiliation(s)
- Simon J Fung
- VA Greater Los Angeles Healthcare System, Los Angeles, CA: Websciences International, Los Angeles, CA
| | - Michael H Chase
- VA Greater Los Angeles Healthcare System, Los Angeles, CA: Websciences International, Los Angeles, CA: Department of Physiology, UCLA School of Medicine, Los Angeles, CA
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81
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Younes M, Loewen A, Ostrowski M, Hanly P. Short-term potentiation in the control of pharyngeal muscles in obstructive apnea patients. Sleep 2014; 37:1833-49. [PMID: 25364079 DOI: 10.5665/sleep.4182] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES To determine if activation of the genioglossus (GG) muscle during obstructive apnea events involves short-term potentiation (STP) and is followed by sustained activation beyond the obstructive phase (after-discharge). DESIGN Physiological study. SETTING Sleep laboratory in a tertiary hospital. PARTICIPANTS Twenty-one patients with obstructive apnea. INTERVENTIONS Polysomnography on continuous positive airway pressure (CPAP) with measurement of genioglossus activity. Brief dial-downs of CPAP to induce obstructive events. MEASUREMENTS AND RESULTS Peak, phasic, and tonic genioglossus activities were measured breath-by-breath before, during, and following three-breath obstructions. Tonic but not phasic activity increased immediately following the first obstructed breath (4.9 ± 1.6 versus 3.6 ± 1.2 %GGMAX; P = 0.01) under conditions where stimuli to genioglossus activation were likely constant, strongly implicating STP in mediating recruitment of tonic activity. Both phasic and tonic activities declined slowly after relief of obstruction (after-discharge). Decay time constants were systematically shorter for phasic than for tonic activity (7.5 ± 3.8 versus 18.1 ± 8.4 sec; P < 0.001). Decay time-constant of peak activity correlated with tonic, but not phasic, recruitment. Cortical arousal near the end of obstruction resulted in a lower after-discharge (P < 0.01). Contribution of tonic activity to the increase in peak activity (6-65%Peak), as well as the decay constant (6-30 sec), varied considerably among patients. CONCLUSIONS Short-term potentiation contributes to recruitment of the genioglossus during obstructive episodes and results in sustained tonic activity beyond the obstructive phase, thereby potentially preventing recurrence of obstruction. Wide response differences among subjects suggest that this mechanism may contribute to severity of the disorder. The after-discharge is inhibited following cortical arousal, potentially explaining arousals' destabilizing effect.
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Affiliation(s)
- Magdy Younes
- Sleep Disorders Centre, Misericordia Health Centre, Winnipeg, Manitoba, Canada ; Sleep Centre, Foothills Medical Centre, University of Calgary, Calgary, Canada
| | - Andrea Loewen
- Sleep Centre, Foothills Medical Centre, University of Calgary, Calgary, Canada
| | - Michele Ostrowski
- Sleep Centre, Foothills Medical Centre, University of Calgary, Calgary, Canada
| | - Patrick Hanly
- Sleep Centre, Foothills Medical Centre, University of Calgary, Calgary, Canada
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82
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O’Halloran KD. Sweet Success Should Set Tongues Wagging. A Portrait of Airway Muscle Injury in Sleep Apnea. Am J Respir Crit Care Med 2014; 189:1299-300. [DOI: 10.1164/rccm.201405-0820ed] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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83
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Eckert DJ, Malhotra A, Wellman A, White DP. Trazodone increases the respiratory arousal threshold in patients with obstructive sleep apnea and a low arousal threshold. Sleep 2014; 37:811-9. [PMID: 24899767 PMCID: PMC4044741 DOI: 10.5665/sleep.3596] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES The effect of common sedatives on upper airway physiology and breathing during sleep in obstructive sleep apnea (OSA) has been minimally studied. Conceptually, certain sedatives may worsen OSA in some patients. However, sleep and breathing could improve with certain sedatives in patients with OSA with a low respiratory arousal threshold. This study aimed to test the hypothesis that trazodone increases the respiratory arousal threshold in patients with OSA and a low arousal threshold. Secondary aims were to examine the effects of trazodone on upper airway dilator muscle activity, upper airway collapsibility, and breathing during sleep. DESIGN Patients were studied on 4 separate nights according to a within-subjects cross-over design. SETTING Sleep physiology laboratory. PATIENTS Seven patients with OSA and a low respiratory arousal threshold. INTERVENTIONS In-laboratory polysomnograms were obtained at baseline and after 100 mg of trazodone was administered, followed by detailed overnight physiology experiments under the same conditions. During physiology studies, continuous positive airway pressure was transiently lowered to measure arousal threshold (negative epiglottic pressure prior to arousal), dilator muscle activity (genioglossus and tensor palatini), and upper airway collapsibility (Pcrit). MEASUREMENTS AND RESULTS Trazodone increased the respiratory arousal threshold by 32 ± 6% (-11.5 ± 1.4 versus -15.3 ± 2.2 cmH2O, P < 0.01) but did not alter the apnea-hypopnea index (39 ± 12 versus 39 ± 11 events/h sleep, P = 0.94). Dilator muscle activity and Pcrit also did not systematically change with trazodone. CONCLUSIONS Trazodone increases the respiratory arousal threshold in patients with obstructive sleep apnea and a low arousal threshold without major impairment in dilator muscle activity or upper airway collapsibility. However, the magnitude of change in arousal threshold was insufficient to overcome the compromised upper airway anatomy in these patients.
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Affiliation(s)
- Danny J. Eckert
- Brigham and Women's Hospital, Division of Sleep Medicine, Sleep Disorders Program and Harvard Medical School, Boston, MA
- Neuroscience Research Australia (NeuRA), and the School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Atul Malhotra
- Brigham and Women's Hospital, Division of Sleep Medicine, Sleep Disorders Program and Harvard Medical School, Boston, MA
- Pulmonary and Critical Care Division, University of California San Diego, La Jolla, CA
| | - Andrew Wellman
- Brigham and Women's Hospital, Division of Sleep Medicine, Sleep Disorders Program and Harvard Medical School, Boston, MA
| | - David P. White
- Brigham and Women's Hospital, Division of Sleep Medicine, Sleep Disorders Program and Harvard Medical School, Boston, MA
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84
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Wang Y, Li C, Feng L, Feng J, Cao J, Chen B. Prevalence of hypertension and circadian blood pressure variations in patients with obstructive sleep apnoea-hypopnoea syndrome. J Int Med Res 2014; 42:773-80. [PMID: 24651995 DOI: 10.1177/0300060513516756] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 11/22/2013] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate the prevalence of hypertension and circadian blood pressure (BP) variations in patients with obstructive sleep apnoea-hypopnoea syndrome (OSAHS). METHODS Patients referred to a sleep clinic underwent polysomnography with measurement of BP at four time points. They were classified into four groups (control, and mild, moderate or severe sleep apnoea) using the apnoea-hypopnoea index (AHI). Circadian variation was assessed using night-time to daytime mean BP (R(N/D)) and morning to evening mean BP (R(M/E)) ratios. RESULTS Hypertension was significantly more common in patients with OSAHS (50.5%) than in controls (30.4%). AHI was positively correlated with hypertension after controlling for related confounders. Mean BP values at all four time points rose with increasing AHI. The increase in night-time and morning values was more pronounced than the increase in daytime and evening values in patients with OSAHS, resulting in loss of the normal BP diurnal rhythm. The R(N/D) and R(M/E) ratios increased with increasing AHI. Daytime BP was significantly correlated with AHI and the lowest oxygen saturation value. CONCLUSION OSAHS was shown to be an independent risk factor for hypertension. It was also associated with loss of the normal BP diurnal rhythm.
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Affiliation(s)
- Yan Wang
- Respiratory Department, Tianjin Medical University General Hospital, Tianjin, China
| | - Caili Li
- Graduate School, Tianjin Medical University, Tianjin, China
| | - Liting Feng
- Respiratory Department, Tianjin Medical University General Hospital, Tianjin, China
| | - Jing Feng
- Respiratory Department, Tianjin Medical University General Hospital, Tianjin, China Division of Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
| | - Jie Cao
- Respiratory Department, Tianjin Medical University General Hospital, Tianjin, China
| | - Baoyuan Chen
- Respiratory Department, Tianjin Medical University General Hospital, Tianjin, China
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85
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Doufas AG. Obstructive Sleep Apnea, Pain, and Opioid Analgesia in the Postoperative Patient. CURRENT ANESTHESIOLOGY REPORTS 2013. [DOI: 10.1007/s40140-013-0047-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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86
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Inoshita A, Kasai T, Takahashi M, Inoshita H, Kasagi S, Kawana F, Ishiwata S, Ohno M, Yamaguchi T, Narui K, Ikeda K. Craniofacial anatomical risk factors in men with obstructive sleep apnea and heart failure: a pilot study. Sleep Breath 2013; 18:439-45. [PMID: 24213810 DOI: 10.1007/s11325-013-0906-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 10/02/2013] [Accepted: 10/28/2013] [Indexed: 12/11/2022]
Abstract
PURPOSE Obstructive sleep apnea (OSA) is complicated with heart failure (HF); however, the reason for this is not well understood. Craniofacial anatomic risk factors may contribute to OSA pathogenesis in HF patients. However, there are no data about cephalometric findings among OSA patients with HF. METHODS Consecutive patients with HF and OSA (defined as total apnea-hypopnea index (AHI) ≥15/h) were enrolled. As controls, OSA patients without HF but matching the test group in age, BMI, and obstructive AHI were also enrolled. RESULTS Overall, 17 OSA patients with HF and 34 OSA patients without HF were compared. There are no significant differences in the characteristics or polysomnographic parameters between 2 groups. In the cephalometric findings, compared with patients without HF, patients with HF showed a significantly greater angle between the line SN to point "A" (SNA) and a longer inferior airway space and greater airway area. However, the tongue area of patients with HF was more than those without HF. CONCLUSIONS The craniofacial structures of OSA patients with HF were different from those without HF. OSA patients with HF had an upper airway anatomy that is more likely to collapse when sleeping while recumbent, despite having a larger airway space.
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Affiliation(s)
- Ayako Inoshita
- Department of Otorhinolaryngology, Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan
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87
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Eckert DJ, Younes MK. Arousal from sleep: implications for obstructive sleep apnea pathogenesis and treatment. J Appl Physiol (1985) 2013; 116:302-13. [PMID: 23990246 DOI: 10.1152/japplphysiol.00649.2013] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Historically, brief awakenings from sleep (cortical arousals) have been assumed to be vitally important in restoring airflow and blood-gas disturbances at the end of obstructive sleep apnea (OSA) breathing events. Indeed, in patients with blunted chemical drive (e.g., obesity hypoventilation syndrome) and in instances when other defensive mechanisms fail, cortical arousal likely serves an important protective role. However, recent insight into the pathogenesis of OSA indicates that a substantial proportion of respiratory events do not terminate with a cortical arousal from sleep. In many cases, cortical arousals may actually perpetuate blood-gas disturbances, breathing instability, and subsequent upper airway closure during sleep. This brief review summarizes the current understanding of the mechanisms mediating respiratory-induced cortical arousal, the physiological factors that influence the propensity for cortical arousal, and the potential dual roles that cortical arousal may play in OSA pathogenesis. Finally, the extent to which existing sedative agents decrease the propensity for cortical arousal and their potential to be therapeutically beneficial for certain OSA patients are highlighted.
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Affiliation(s)
- Danny J Eckert
- Neuroscience Research Australia (NeuRA Randwick, New South Wales, Australia
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88
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Azarbarzin A, Ostrowski M, Moussavi Z, Hanly P, Younes M. Contribution of arousal from sleep to postevent tachycardia in patients with obstructive sleep apnea. Sleep 2013; 36:881-9. [PMID: 23729931 PMCID: PMC3649830 DOI: 10.5665/sleep.2716] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Heart rate increases after obstructive events in patients with obstructive sleep apnea (OSA). This response is generally attributed to arousal from sleep. Opening of the obstructed airway, however, is associated with ventilatory and hemodynamic changes that could result in physiologic responses unrelated to arousal. Our objective was to determine the contribution of these physiologic responses to postevent tachycardia. DESIGN Analysis of data obtained during previous research protocols. SETTING Academic sleep laboratory. PARTICIPANTS Twenty patients with severe OSA. INTERVENTIONS Patients were placed on a continuous positive airway pressure (CPAP) device. CPAP was reduced during sleep to different levels (dial-downs), producing obstructive events of varying severity. Some dial-downs with severe obstruction were maintained until spontaneous airway opening. In others, CPAP was increased after three obstructed breaths, terminating the events approximately 10 sec before spontaneous termination in long dial-downs. MEASUREMENT AND RESULTS Beat-by-beat heart rate (HR) was measured for 20 sec following airway opening. Spontaneous opening during sustained dial-downs occurred 21.9 ± 8.4 sec after dial-down, was associated with arousal, and resulted in the greatest postevent tachycardia (7.8 ± 4.0 min(-1)). However, deliberate termination of events (12.2 ± 2.6 sec after dial-down) was also followed by tachycardia that, in the absence of cortical arousal, showed a dose-response behavior, increasing with severity of obstruction and without apparent threshold. ΔHR following deliberately brief, severe obstruction (3.8 ± 3.0 min(-1)) was approximately half the ΔHR that followed spontaneous opening of equally severe obstructions despite the shorter duration and absence of cortical arousal. CONCLUSIONS Postevent tachycardia is due in large part to physiologic (arousal-unrelated) responses that occur upon relief of obstruction.
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Affiliation(s)
- Ali Azarbarzin
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Michele Ostrowski
- Sleep Center, Foothills Medical Centre, University of Calgary, Calgary, Canada
| | - Zahra Moussavi
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Patrick Hanly
- Sleep Center, Foothills Medical Centre, University of Calgary, Calgary, Canada
| | - Magdy Younes
- Sleep Disorders Centre, Misericordia Health Centre, Winnipeg, Manitoba, Canada
- Sleep Center, Foothills Medical Centre, University of Calgary, Calgary, Canada
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89
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Volgin DV, Stettner GM, Kubin L. Circadian dependence of receptors that mediate wake-related excitatory drive to hypoglossal motoneurons. Respir Physiol Neurobiol 2013; 188:301-7. [PMID: 23665050 DOI: 10.1016/j.resp.2013.04.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/29/2013] [Accepted: 04/30/2013] [Indexed: 10/26/2022]
Abstract
Serotonin (5-HT), norepinephrine and orexins (ORX) are the three best established mediators of wake-related activation of hypoglossal (XII) motoneurons that innervate the muscles of the tongue. Since the tongue's use is temporarily closely aligned with the rest-activity cycle, we tested whether expression of mRNA for relevant 5-HT, norepinephrine and ORX receptors varies in the XII nucleus with the rest-activity cycle. Adult rats (n=7-9/group) were decapitated at 8-9 am (near rest period onset) or at 6-7 pm (near active period onset). Tissue micropunches were extracted from medullary slices containing the XII motor and sensory external cuneate (ECN) nuclei. 5-HT2A, α1-adrenergic and ORX type 2 receptor mRNAs were quantified using RT-PCR. Only 5-HT2A receptor mRNA levels differed between the two time points and were higher at the active period onset; no differences were detected in the ECN. Consistent with the mRNA results, 5-HT2A protein levels were also higher in the XII nucleus at the active period onset than at rest onset. Thus, the endogenous serotonergic excitatory drive to XII motoneurons may be enhanced through circadian- or activity-dependent mechanisms that increase the availability of 5-HT2A receptors prior to the active period. Conversely, reduced levels of 5-HT2A receptors during the rest-sleep period may exacerbate the propensity for sleep-disordered breathing in subjects with anatomically compromised upper airway.
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Affiliation(s)
- Denys V Volgin
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104-6046, USA.
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