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The Canadian Journal of Cardiology May 2021Patients with obstructive sleep apnea (OSA) experience repetitive partial or complete airway collapse during sleep resulting in nocturnal hypoxia-normoxia cycling, and... (Review)
Review
Patients with obstructive sleep apnea (OSA) experience repetitive partial or complete airway collapse during sleep resulting in nocturnal hypoxia-normoxia cycling, and are at increased cardiovascular risk. The number of apneas and hypopneas indexed per hour of sleep (apnea-hypopnea index) along with the associated intermittent hypoxia predict the increased cardiovascular risk; thus, their attenuation or prevention are objectives of OSA therapy. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA and, when effective, mitigates the apnea-hypopnea index and hypoxemia. As such, it is reasonable to expect CPAP would decrease cardiovascular risk. However, 3 recent randomized clinical trials of CPAP vs usual care did not show any significant effects of CPAP in attenuating incident cardiovascular events in patients with OSA. In this review, we discuss these studies in addition to potential complementary therapeutic options to CPAP (eg, neurostimulation) and conclude with suggested therapeutic targets for future interventional studies (eg, the autonomic nervous system). Although these areas of research are exciting, they have yet to be tested to any similar degree of rigour as CPAP.
Topics: Cardiovascular Diseases; Continuous Positive Airway Pressure; Heart Disease Risk Factors; Humans; Sleep Apnea, Obstructive
PubMed: 33610689
DOI: 10.1016/j.cjca.2021.01.027 -
Sleep Aug 2023We aimed to characterize the cerebral hemodynamic response to obstructive sleep apnea/hypopnea events, and evaluate their association to polysomnographic parameters. The...
STUDY OBJECTIVES
We aimed to characterize the cerebral hemodynamic response to obstructive sleep apnea/hypopnea events, and evaluate their association to polysomnographic parameters. The characterization of the cerebral hemodynamics in obstructive sleep apnea (OSA) may add complementary information to further the understanding of the severity of the syndrome beyond the conventional polysomnography.
METHODS
Severe OSA patients were studied during night sleep while monitored by polysomnography. Transcranial, bed-side diffuse correlation spectroscopy (DCS) and frequency-domain near-infrared diffuse correlation spectroscopy (NIRS-DOS) were used to follow microvascular cerebral hemodynamics in the frontal lobes of the cerebral cortex. Changes in cerebral blood flow (CBF), total hemoglobin concentration (THC), and cerebral blood oxygen saturation (StO2) were analyzed.
RESULTS
We considered 3283 obstructive apnea/hypopnea events from sixteen OSA patients (Age (median, interquartile range) 57 (52-64.5); females 25%; AHI (apnea-hypopnea index) 84.4 (76.1-93.7)). A biphasic response (maximum/minimum followed by a minimum/maximum) was observed for each cerebral hemodynamic variable (CBF, THC, StO2), heart rate and peripheral arterial oxygen saturation (SpO2). Changes of the StO2 followed the dynamics of the SpO2, and were out of phase from the THC and CBF. Longer events were associated with larger CBF changes, faster responses and slower recoveries. Moreover, the extrema of the response to obstructive hypopneas were lower compared to apneas (p < .001).
CONCLUSIONS
Obstructive apneas/hypopneas cause profound, periodic changes in cerebral hemodynamics, including periods of hyper- and hypo-perfusion and intermittent cerebral hypoxia. The duration of the events is a strong determinant of the cerebral hemodynamic response, which is more pronounced in apnea than hypopnea events.
Topics: Female; Humans; Sleep Apnea, Obstructive; Hemodynamics; Sleep Apnea Syndromes; Spectroscopy, Near-Infrared; Airway Obstruction
PubMed: 37336476
DOI: 10.1093/sleep/zsad122 -
Emerging Topics in Life Sciences Dec 2023Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is a common disorder characterised by repetitive episodes of the complete or partial collapse of the pharyngeal...
Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is a common disorder characterised by repetitive episodes of the complete or partial collapse of the pharyngeal airway during sleep. This results in cessation (apnoea) or reduction (hypopnoea) of airflow, leading to oxygen desaturation and sleep fragmentation. An individual's disposition to develop OSAHS depends on the collapsibility of a segment of the upper airway. The degree of collapsibility can be quantified by the balance between occluding or extraluminal pressures of the surrounding tissues. Patients can experience snoring, unrefreshing sleep, witnessed apnoeas, waking with a choking sensation and excessive daytime sleepiness. OSAHS has a broad range of consequences, including cardiovascular, metabolic, and neurocognitive sequelae. Treatment options include lifestyle measures, in particular weight loss, and strategies to maintain upper airway patency overnight, including continuous positive airway pressure, mandibular advancement devices and positional modifiers.
Topics: Humans; Sleep Apnea, Obstructive; Syndrome; Lung; Snoring; Continuous Positive Airway Pressure
PubMed: 38130167
DOI: 10.1042/ETLS20180939 -
Best Practice & Research. Clinical... Dec 2022This review provides a summary for obstetricians, midwives, other health professionals and women contemplating pregnancy about the interactions between pregnancy and... (Review)
Review
This review provides a summary for obstetricians, midwives, other health professionals and women contemplating pregnancy about the interactions between pregnancy and breathing during sleep. This review will first examine the normal physiological changes of pregnancy and their relationship to sleep-disordered breathing (SDB), and it will then summarise the current knowledge of SDB in pregnancy. Many changes in the respiratory system during pregnancy, particularly during the third trimester, can alter respiratory function during sleep, increasing the incidence and severity of SDB. These changes include increased ventilatory drive and metabolic rate, reduced functional residual capacity and residual volume, increased alveolar-arterial oxygen gradients and changes in the upper airway. The clinical importance of these changes during pregnancy is demonstrated by the increased incidence of snoring and obstructive sleep apnoea hypopnoea syndrome. As SDB is associated with obesity, the increasing incidence of obesity pre-pregnancy will likely increase SDB during pregnancy over the next decade. If a physician is asked to review a pregnant patient, they should always consider the possibility of SDB.
Topics: Pregnancy; Female; Humans; Sleep Apnea, Obstructive; Snoring; Sleep Apnea Syndromes; Sleep Wake Disorders; Obesity
PubMed: 36443159
DOI: 10.1016/j.bpobgyn.2022.11.004 -
Expert Opinion on Pharmacotherapy 2023Clinical presentation of both insomnia and obstructive sleep apnea (COMISA) is common. Approximately 30% of clinical cohorts with OSA have insomnia symptoms and vice... (Review)
Review
INTRODUCTION
Clinical presentation of both insomnia and obstructive sleep apnea (COMISA) is common. Approximately 30% of clinical cohorts with OSA have insomnia symptoms and vice versa. The underlying pathophysiology of COMISA is multifactorial. This poses a complex clinical challenge. Currently, there are no clinical guidelines or recommendations outside of continuous positive airway pressure (CPAP) therapy and cognitive behavioral therapy for insomnia (CBTi). Clinically translatable precision medicine approaches to characterize individual causes or endotypes may help optimize future pharmacological management of COMISA.
AREAS COVERED
This review article provides an up-to-date account of COMISA and its consequences, the underlying pathophysiology of sleep apnea, insomnia and COMISA, current treatment approaches and limitations, pharmacotherapy targets and future priorities.
EXPERT OPINION
There are multiple promising emerging therapies, but clinical trial data specifically in COMISA populations are lacking. This is a priority for future investigation to inform development of evidence-based guidelines. Pharmacotherapies, particularly for insomnia, do not target the underlying causes of the disorder thus, are indicated for short-term use only and should remain second line. Future multidisciplinary research should be directed toward the multifactorial nature of COMISA and the challenges of adapting COMISA treatment in clinical practice and overcoming the practical barriers that health-care providers and consumers encounter.
Topics: Humans; Sleep Initiation and Maintenance Disorders; Sleep Apnea, Obstructive; Sleep Apnea Syndromes; Comorbidity; Continuous Positive Airway Pressure
PubMed: 38099435
DOI: 10.1080/14656566.2023.2292186 -
Heart (British Cardiac Society) Nov 2023Sleep-disordered breathing (SDB) is common in individuals with established cardiovascular disease (CVD), particularly those with heart failure (HF). There are two main... (Randomized Controlled Trial)
Randomized Controlled Trial
Sleep-disordered breathing (SDB) is common in individuals with established cardiovascular disease (CVD), particularly those with heart failure (HF). There are two main types of SDB, central sleep apnoea (CSA) and obstructive sleep apnoea (OSA) which frequently overlap as mixed SDB. Investigating for SDB could be considered in patients with excessive daytime sleepiness, male sex, high body mass index, low ejection fraction, atrial fibrillation (AF), in patients with no dipping blood pressure pattern, recurrent paroxysms of nocturnal dyspnoea or when an apnoea is witnessed. Excessive daytime sleepiness is less likely to be reported by patients with HF than by the general population. In patients with CVD and OSA, continuous positive airway pressure (CPAP) ventilation for over 4 hours daily reduced the risk of major adverse cardiovascular events, but there was no reduction in mortality. In patients with AF and OSA treated with AF ablation, CPAP use was associated with a reduced risk of recurrence of AF. In patients with HF and OSA, small studies have demonstrated that CPAP improves symptoms, brain natriuretic peptide levels and ejection fraction, but data on survival are lacking. Treatment remains unclear in patients with HF and CSA. The presence of CSA may be a defensive adaptive response to HF, and effectively treating CSA as demonstrated in a randomised clinical trial of adaptive servo-ventilation caused more harm than benefit when compared to optimal medical therapy. Thus, the focus of treating CSA should remain on improving the underlying HF by optimising medical therapy and, if indicated, cardiac resynchronisation therapy.
Topics: Humans; Male; Cardiovascular Diseases; Sleep Apnea Syndromes; Sleep Apnea, Central; Sleep Apnea, Obstructive; Heart Failure; Atrial Fibrillation; Disorders of Excessive Somnolence
PubMed: 37607811
DOI: 10.1136/heartjnl-2019-316375 -
IEEE Transactions on Bio-medical... Apr 2022The physiological mechanisms involved in cardio-respiratory responses to sleep apnea events are not yet fully elucidated. A model-based approach is proposed to analyse...
OBJECTIVE
The physiological mechanisms involved in cardio-respiratory responses to sleep apnea events are not yet fully elucidated. A model-based approach is proposed to analyse the acute desaturation response to obstructive apneas.
METHODS
An integrated model of cardio-respiratory interactions was proposed and parameters were identified, using an evolutionary algorithm, on a database composed of 107 obstructive apneas acquired from 10 patients (HYPNOS clinical study). Unsupervised clustering was applied to the identified parameters in order to characterize the phenotype of each response to obstructive apneas.
RESULTS
A close match was observed between simulated oxygen saturation ( SaO) and experimental SaO in all identifications (median RMSE = 1.3892 %). Two clusters of parameters, associated with different dynamics related to sleep apnea and periodic breathing were obtained.
CONCLUSION AND SIGNIFICANCE
The proposed patient and event-specific model-based analysis provides understanding on specific desaturation patterns, consequent to apnea events, with potential applications for personalized diagnosis and treatment.
Topics: Airway Obstruction; Humans; Oxygen; Sleep Apnea Syndromes; Sleep Apnea, Obstructive
PubMed: 34665719
DOI: 10.1109/TBME.2021.3121170 -
Journal of Sleep Research Dec 2021Central sleep apneas and periodic breathing are poorly described in childhood. The aim of the study was to describe the prevalence and characteristics of central sleep...
Central sleep apneas and periodic breathing are poorly described in childhood. The aim of the study was to describe the prevalence and characteristics of central sleep apnea and periodic breathing in children with associated medical conditions, and the therapeutic management. We retrospectively reviewed all poly(somno)graphies with a central apnea index ≥ 5 events per hr in children aged > 1 month performed in a paediatric sleep laboratory over a 6-year period. Clinical data and follow-up poly(somno)graphies were gathered. Ninety-five out of 2,981 patients (3%) presented central sleep apnea: 40% were < 1 year, 41% aged 1-6 years, and 19% aged ≥ 6 years. Chiari malformation was the most common diagnosis (13%). Mean central apnea index was 20 ± 30 events per hr (range 5-177). Fifty-eight (61%) children had an exclusive central pattern with < 5 obstructive events per hr. Periodic breathing was present in 79 (83%) patients, with a mean percentage of time with periodic breathing of 9 ± 16%. Among periodic breathing episodes, 40% appeared after a sigh, 8% after an obstructive event, 6% after breathing instability and 2% after bradypnea. The highest clinical apnea index and percentage of time with periodic breathing were observed in children with encephalopathy and/or epilepsy (68 ± 63 events per hr and 30 ± 34%). Clinical apnea index did not differ according to age, while periodic breathing duration was longer in children > 1 year old. Watchful waiting was performed in 22 (23%) patients with spontaneous improvement in 20. Other treatments (upper airway or neurosurgery, nocturnal oxygen therapy, continuous positive airway pressure, non-invasive ventilation) were effective in selected patients. Central sleep apnea is rare in children and comprises heterogeneous conditions. Sleep studies are essential for the diagnosis, characterization and management of central sleep apnea.
Topics: Child; Continuous Positive Airway Pressure; Humans; Infant; Polysomnography; Retrospective Studies; Sleep Apnea, Central; Sleep Apnea, Obstructive
PubMed: 34075643
DOI: 10.1111/jsr.13388 -
European Respiratory Review : An... Sep 2019Obstructive sleep apnoea (OSA) syndrome affects about 13% of the male and 7-9% of the female population. Hypoxia, oxidative stress and systemic inflammation link OSA and... (Review)
Review
Obstructive sleep apnoea (OSA) syndrome affects about 13% of the male and 7-9% of the female population. Hypoxia, oxidative stress and systemic inflammation link OSA and cardiovascular and metabolic consequences, including coronary artery disease. Current research has identified several clinical phenotypes, and the combination of breathing disturbances during sleep, systemic effects and end-organ damage might help to develop personalised therapeutic approaches. It is unclear whether OSA is a risk factor for acute coronary syndrome (ACS) and might affect its outcome. On the one hand, OSA in patients with ACS may worsen prognosis; on the other hand, OSA-related hypoxaemia could favour the development of coronary collaterals, thereby exerting a protective effect. It is unknown whether positive airway pressure treatment may influence adverse events and consequences of ACS. In non-sleepy patients with OSA and stable coronary artery disease, randomised controlled trials failed to show that continuous positive airway pressure (CPAP) treatment protected against cardiovascular events. Conversely, uncontrolled studies suggested positive effects of CPAP treatment in such patients. Fewer data are available in subjects with ACS and OSA, and results of randomised controlled studies on the effects of CPAP are expected shortly. Meanwhile, the search for reliable markers of risk continues. Recent studies suggest that daytime sleepiness may indicate a more severe OSA phenotype with regard to cardiovascular risk. Finally, some studies suggest sex-related differences. The picture is still incomplete, and the potential role of OSA in patients with ACS awaits confirmation, as well as clear definition of subgroups with different degrees of risk.
Topics: Acute Coronary Syndrome; Continuous Positive Airway Pressure; Female; Hemodynamics; Humans; Lung; Male; Patient Compliance; Prevalence; Respiration; Risk Factors; Sleep; Sleep Apnea, Obstructive; Treatment Outcome
PubMed: 31366458
DOI: 10.1183/16000617.0114-2018 -
British Journal of Hospital Medicine... Sep 2022Obstructive sleep apnoea represents a sizable public health and economic burden. Owing to rising obesity rates, the prevalence of obstructive sleep apnoea is increasing,... (Review)
Review
Obstructive sleep apnoea represents a sizable public health and economic burden. Owing to rising obesity rates, the prevalence of obstructive sleep apnoea is increasing, and it is a condition that is significantly underdiagnosed. Exacerbated by the COVID-19 pandemic, the backlog of elective surgeries is also sizable and growing. A combination of these factors means that many patients due to have surgery will have obstructive sleep apnoea, either diagnosed or otherwise. Patients with obstructive sleep apnoea have a significantly increased risk of operative complications, but the evidence base for optimum perioperative management of these patients is limited. This article reviews sleep apnoea, its prevalence and its impact on operative management and perioperative outcomes for patients. The evidence base for screening and treating undiagnosed obstructive sleep apnoea is also comprehensively assessed. Finally, a pathway to manage patients with possible undiagnosed obstructive sleep apnoea is proposed, and areas for further research identified.
Topics: COVID-19; Continuous Positive Airway Pressure; Humans; Pandemics; Perioperative Medicine; Sleep Apnea, Obstructive
PubMed: 36193921
DOI: 10.12968/hmed.2022.0297