Intranasal oxytocin increases respiratory rate and reduces obstructive event duration and oxygen desaturation in obstructive sleep apnea patients: a randomized double blinded placebo controlled study

BACKGROUND

Activation of the oxytocin network has shown benefits in animal models of Obstructive Sleep Apnea (OSA) as well as other cardiorespiratory diseases. We sought to determine if nocturnal intranasal oxytocin administration could have beneficial effects in reducing the duration and/or frequency of obstructive events in obstructive sleep apnea subjects.

METHODS

Two sequential standard "in-lab" polysomnogram (PSG) sleep studies were performed in patients diagnosed with OSA that were randomly assigned to initially receive either placebo or oxytocin (40 i.u.) administered intranasally in this double blinded randomized placebo controlled study. Changes in cardiorespiratory events during sleep, including apnea and hypopnea durations and frequency, risk of event-associated bradycardias, arterial oxygen desaturation and respiratory rate were assessed in 2 h epochs following sleep onset. Oxytocin significantly decreased the duration of obstructive events, as well as the oxygen desaturations and incidence of bradycardia that were associated with these events. Notably, oxytocin increased respiratory rate during non-obstructive periods. There were no significant changes in sleep architecture and no adverse effects were reported.

CONCLUSIONS

Oxytocin administration can benefit OSA subjects by reducing the duration and adverse consequences of obstructive events. Oxytocin could also be beneficial in situations involving respiratory depression as oxytocin increased respiratory rate. Additional studies are needed to further understand the mechanisms by which oxytocin promotes these changes in cardiorespiratory function. The long-term efficacy and optimal dose of intranasal oxytocin treatment should also be determined in OSA subjects. ClinicalTrials.gov NCT03148899.

Increased respiratory disturbance index measured using an advanced device algorithm is associated with heart failure development

Previous studies suggested that sleep-disordered breathing was associated with cardiovascular diseases such as heart failure (HF). Recently, algorithms of cardiac implantable electronic devices (CIEDs) have been developed to detect advanced sleep apnea (SA); the Apnea Scan (AP Scan) being an example. The purpose of this study was to investigate the association between respiratory disturbance index (RDI) measured using the AP Scan algorithm and HF development. We retrospectively studied consecutive patients with CIEDs equipped with the AP Scan algorithm which were implanted between December 1, 2011 and March 31, 2019. These patients were divided into 2 groups according to the trends of RDI: patients with a continually high RDI > 30 (severe SA group) and those without a continually high RDI (non-severe SA group). There were 16 and 46 patients in the severe and non-severe SA groups, respectively. Increased left ventricular end-diastolic and end-systolic dimensions were observed in the severe SA group. Regarding cardiovascular events, HF was observed in 8 patients (50.0%) in the severe SA group and 1 patient (2.2%) in the non-severe SA group; thus, there was a significantly higher proportion of patients with HF in the severe SA group. In conclusion, continually high RDI was associated with HF development in patients with CIEDs equipped with the AP Scan algorithm. Therefore, an elevated RDI may be a risk factor for the development of HF in patients with CIEDs.

Association Between Breathing Route, Oxygen Desaturation, and Upper Airway Morphology

OBJECTIVES/HYPOTHESIS

This study aimed to assess the role of capnography in objectively evaluating breathing routes during drug-induced sleep endoscopy (DISE) and further elucidate the relationship between breathing route, obstructive sleep apnea (OSA) severity, and DISE findings.

STUDY DESIGN

Prospective observational study.

METHODS

Nighty-five patients with established OSA were recruited for this study from May 2017 to May 2019. DISE was performed in the operating room. Sedation was maintained with propofol using a target-controlled infusion system and the depth of sedation was monitored based on the bispectral index. The breathing routes, which included oral breathing, oronasal breathing, and nasal breathing, were detected using capnography. DISE findings were recorded using the VOTE (velum, oropharynx, base of tongue, and epiglottis) classification.

RESULTS

Patients with mouth breathing were associated with increased OSA severity, worse oximetric variables, and higher body mass index in comparison with those with other breathing routes. Mouth breathing was associated with a higher degree and higher prevalence of lateral pharyngeal wall collapse and tongue base collapse during DISE.

CONCLUSIONS

Mouth breathing was significantly associated with worse oxygen desaturation and increased degree of upper airway collapse. Therefore, patients with mouth breathing during propofol-based intravenous anesthesia should be carefully monitored.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E659-E664, 2021.

Association between non-alcoholic fatty liver disease and obstructive sleep apnea

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an emerging liver disease and currently the most common cause of incidental abnormal liver tests. The pathogenesis of NAFLD is multifactorial and many mechanisms that cause fatty liver infiltration, inflammation, oxidative stress and progressive fibrosis have been proposed. Obstructive sleep apnea (OSA) may be linked with the pathogenesis and the severity of NAFLD.

AIM

To study the association between NAFLD and OSA considering also the efficacy of continuous positive airway pressure (CPAP) treatment.

METHODS

A PubMed search was conducted using the terms “non-alcoholic fatty liver disease AND (obstructive sleep apnea OR obstructive sleep disorders OR sleep apnea)”. Research was limited to title/abstract of articles published in English in the last 5 years; animal and child studies, case reports, commentaries, letters, editorials and meeting abstracts were not considered. Data were extracted on a standardized data collection table which included: First author, publication year, country, study design, number of patients involved, diagnosis and severity of OSA, diagnosis of NAFLD, patient characteristics, results of the study.

RESULTS

In total, 132 articles were initially retrieved on PubMed search and 77 in the last five years. After removal of irrelevant studies, 13 articles were included in the qualitative analysis. There was a total of 2753 participants across all the studies with a mean age between 42 and 58 years. The proportion of males ranged from 21% to 87.9% and the mean body mass index ranged from 24.0 to 49.9 kg/m². The results of this review showed an increased prevalence of NAFLD in patients with diagnosis of OSA, even in the absence of coexisting comorbidities such as obesity or metabolic syndrome. Furthermore, the severity of NAFLD is associated with the increase in OSA severity. Effective CPAP treatment, although not always decisive, may stabilize or slow NAFLD progression with benefits on metabolic and cardiovascular functions.

CONCLUSION

In NAFLD patients, although asymptomatic, it is recommended to systematically perform polysomnography in order to early and better treat them before the development of potentially life threatening systemic dysfunctions.

Pacing therapies for sleep apnea and cardiovascular outcomes: A systematic review

PURPOSE

Phrenic and hypoglossal nerve pacing therapies have shown benefit in sleep apnea. We sought to analyze the role of pacing therapies in sleep apnea and their impact on heart failure.

METHODS

A comprehensive literature search in PubMed and Google Scholar from inception to August 5, 2019, was performed. A meta-analysis was performed using fixed effects model to calculate mean difference (MD) with 95% confidence interval (CI).

RESULTS

Six studies were eligible and included 626 patients, of whom 334 were in the control arm and 393 were in the experimental arm. Phrenic nerve pacing (MD - 23.20 events/h, 95% CI - 27.96 to - 18.44, p < 0.00001) and hypoglossal nerve pacing (MD - 20.24 events/h, 95% CI - 23.22 to - 17.27, p < 0.00001) were associated with improvements in apnea-hypopnea index (AHI). Phrenic nerve pacing was associated with a trend towards improvements in left ventricular ejection fraction (MD 3.95%, 95% CI - 0.04 to 7.94, p = 0.05). Hypoglossal and phrenic nerve pacing were associated with improvements in the quality of life as assessed by improvements in Epworth sleepiness scale (MD 3.71 points, 95% CI 2.89 to 4.54, p < 0.00001).

CONCLUSIONS

Our analysis suggests that phrenic and hypoglossal nerve pacing improves AHI and quality of life with a trend towards improvement in left ventricular ejection fraction, especially in central sleep apnea. Complications were high but future refinement in technology will likely improve clinical outcomes and minimize complications.

How might non nutritional sucking protect from sudden infant death syndrome

Epidemiology has identified an association between the use of pacifiers and protection from sudden infant death syndrome (SIDS). The use of pacifiers for SIDS prevention fails to gain adoption partly because there is no widely accepted physiologic mechanism to explain the epidemiologic association. Additionally, the scientific literature available on pacifier use focuses largely on the probable adverse effects. We hypothesize that pacifier use and all other forms of non-nutritional sucking (specifically digit sucking, also known as thumb sucking) is a life saving defense mechanism meant to splint open and stabilize the collapsible portion of the upper airway in infants.The main objective of this review article is to propose a mechanism to explain how pacifiers might help prevent SIDS. If the medical community accepts this mechanism, it can help promote pacifier use by the public and potentially reduce the incidence of SIDS.

Witnessed sleep apneas together with elevated plasma glucose are predictors of COPD exacerbations

Objective

Sleep apnea and elevated plasma glucose associates with inflammation which associates with the risk of COPD exacerbations. We investigated the risk of exacerbations in individuals with COPD, witnessed sleep apneas, and elevated plasma glucose.

Methods

From the Copenhagen City Heart Study cohort, we identified 564 individuals with COPD (forced expiratory volume in 1 sec divided by forced vital capacity, FEV₁/FVC<0.70), no asthma, above 40 years of age, and more than 10 pack-years of smoking history, with information on witnessed apneas and levels of plasma glucose. We prospectively recorded hospital admissions with COPD exacerbations during maximum available follow-up (26.3 years; mean 10.7 years). Cox-regression analyses were used to analyze the risk of COPD exacerbations.

Results

We identified 74 (13%) individuals with sleep apnea without elevated plasma glucose, 70 (12%) had elevated plasma glucose (above 6.9 mM (>125 mg/dL)) without sleep apnea and 11 individuals had the presence of both conditions. In univariable analysis, witnessed apneas together with elevated plasma glucose had a high risk of exacerbations, hazard ratio (HR) = 5.81 (2.34–14.4, p = 0.0001) compared to those without sleep apnea and without elevated plasma glucose. Multivariable analysis, adjusting for several risk factors of exacerbations, showed a similar result, HR = 3.45 (1.13–10.5, p = 0.03). Both presence of sleep apnea without elevated plasma glucose and the presence of elevated plasma glucose without sleep apnea showed no associations with the risk of exacerbations.

Conclusions

Witnessed sleep apneas in COPD are associated with increased risk of exacerbations, but only among those with elevated plasma glucose.

Prediction of sleep-disordered breathing after stroke

OBJECTIVE/BACKGROUND

Sleep-disordered breathing (SDB) is highly prevalent after stroke and is associated with poor outcomes. Currently, after stroke, objective testing must be used to differentiate patients with and without SDB. Within a large, population-based study, we evaluated the usefulness of a flexible statistical model based on baseline characteristics to predict post-stroke SDB.

PATIENTS/METHODS

Within a population-based study, participants (2010-2018) underwent SDB screening, shortly after ischemic stroke, with a home sleep apnea test. The respiratory event index (REI) was calculated as the number of apneas and hypopneas per hour of recording; values ≥10 defined SDB. The distributed random forest classifier (a machine learning technique) was applied to predict SDB with the following as predictors: demographics, stroke risk factors, stroke severity (NIHSS), neck and waist circumference, palate position, and pre-stroke symptoms of snoring, apneas, and sleepiness.

RESULTS

Within the total sample (n = 1330), median age was 65 years; 47% were women; 32% non-Hispanic white, 62% Mexican American, and 6% African American. SDB was found in 891 (67%). The area under the receiver operating characteristic curve, a measure of predictive ability, applied to the validation sample was 0.75 for the random forest model. Random forest correctly classified 72.5% of validation samples.

CONCLUSIONS

In this large, ethnically diverse, population-based sample of ischemic stroke patients, prediction models based on baseline characteristics and clinical measures showed fair rather than clinically reliable performance, even with use of advanced machine learning techniques. Results suggest that objective tests are still needed to differentiate ischemic stroke patients with and without SDB.

The severity of sleep hypoventilation in stable chronic obstructive pulmonary disease

PURPOSE

An increase in PaCO₂ is the element that defines sleep hypoventilation (SH). We queried if patients with SH, and those with PaCO₂ increases during sleep for shorter time periods than SH (shamSH) differed from the patients without SH (noSH) in other ways.

METHODS

This was a retrospective re-analysis of data from 100 stable inpatients with COPD with and without chronic hypercapnic respiratory failure. COPD was defined by criteria of the Global initiative for Chronic Obstructive Lung Disease (GOLD). For this study, SH was defined by an increase in PaCO₂ ≥ 1.33 kPa to a value exceeding 6.7 kPa for ≥ 10 min (≥ 20 epochs of 30 s). Patients fulfilling the increase in PaCO₂ for less than 10 min (1-19 epochs) were designated shamSH. All patients had daytime arterial blood gases, lung function tests, and polysomnography (PSG) with transcutaneous CO₂ (PtcCO₂).

RESULTS

Of 100 patients, 25 had PtcCO₂ increase ≥ 1.33 kPa. One never exceeded 6.7 kPa, 15 had SH, and 9 shamSH. SH and shamSH patients had extra CO₂ load (= PtcCO₂*time) both during and between the SH periods compared to the noSH group, the SH group more than the shamSH group.

CONCLUSION

Using CO₂ load as a measure of severity of sleep hypoventilation, SH patients have worse hypoventilation than the shamSH. Both shamSH and SH groups have extra CO₂ load during and between SH periods, indicating that the SH/shamSH patients may represent a separate group of true hypoventilators during sleep.

Advances and challenges in pursuing biomarkers for obstructive sleep apnea: Implications for the cardiovascular risk

Obstructive sleep apnea (OSA) is a common clinical condition associated with increased cardiovascular morbidity and mortality. Recent evidence from clinical studies and animal models suggest that OSA can promote cardiovascular disease by inducing autonomic, hemodynamic, inflammatory and metabolic dysregulation. However, most of the evidence addressing hard endpoints in humans is derived from observational studies. Several challenges have been noted in the pursuit of a comprehensive knowledge base about the impact of OSA including: 1) the precise mechanisms by which OSA causes metabolic and cardiovascular consequences are not clear, which limits our current ability to address potential targets in OSA; 2) several patients with OSA, even with severe forms, present with no or mild daytime symptoms. Beyond the obvious challenges for obtaining good adherence for conventional OSA treatments, there is evidence that symptomatic vs. asymptomatic patients with OSA do not necessarily have the same metabolic and cardiovascular outcomes; and 3) the cardiovascular response to OSA treatment may vary even in those patients with good adherence. In this scenario, there is an obvious need to develop biomarkers in the OSA research area. This review focuses on describing the advances that have occurred so far in exploring potential OSA biomarkers with clear emphasis for the cardiovascular risk. Particular attention will be devoted to discuss molecular biomarkers including the potential role of microRNAs, proteomics and metabolomics. We also discuss the major challenges and perspectives in this growing research field.

Circulating levels of oxidized low-density lipoprotein in patients with obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is associated with an increased risk of developing atherosclerotic cardiovascular disease (ASCVD). Patients with OSA have increased levels of oxidative stress and several studies have shown higher levels of oxidative stress markers. Oxidized-LDL (Ox-LDL) is an important risk factor for ASCVD and a number of studies have measured its levels in patients with OSA, though results from these studies are conflicting. This meta-analysis aimed to reassess circulating levels of Ox-LDL in patients with OSA in comparison with controls.

METHODS

Studies evaluating Ox-LDL levels in patients with OSA and controls were explored in databases of PubMed, EMBASE, Scopus, and Web of Science. Two authors independently performed the search from January 1990 to February 2019. Two authors independently screened the studies according to title, abstract, and full text. In addition, the Newcastle-Ottawa Quality Assessment Scale was utilized to evaluate the quality of the studies. The impact of OSA on Ox-LDL levels was determined using the random effects model.

RESULTS

Of 195 articles retrieved, 98 were duplicates, 49 were excluded by title, 20 excluded by abstract, and 22 by full texts. Six eligible studies were included in the meta-analysis. Pooled analysis demonstrated that Ox-LDL increased in patients with OSA compared with controls. In addition, subgroup analysis revealed that studies matching age or BMI between OSA patients and controls showed no significant difference between patients with OSA and healthy controls, while unmatched studies had higher levels of Ox-LDL in patients with OSA in comparison with controls.

CONCLUSION

This study demonstrated higher circulating concentrations of Ox-LDL in patients with OSA. However, no significant difference was found in studies in which patients and controls were matched for age and BMI, suggesting the involvement of these two confounding factors as a cause for elevated concentrations of circulating Ox-LDL in patients with OSA.

Symptom subtypes and cognitive function in a clinic-based OSA cohort: a multi-centre Canadian study

BACKGROUND

Distinct symptom subtypes are found in patients with OSA. The association between these subtypes and neurocognitive function is unclear.

OBJECTIVE

The purposes of this study were to assess whether OSA symptom subtypes are present in a cohort of Canadian patients with suspected OSA and evaluate the relationship between subtypes and neurocognitive function.

METHODS

Patients with suspected OSA who completed a symptom questionnaire and underwent testing for OSA were included. Symptom subtypes were identified using latent class analysis. Associations between subtypes and neurocognitive outcomes (Montreal Cognitive Assessment [MoCA], Rey Auditory Verbal Learning Test [RAVLT], Wechsler Adult Intelligence Scale [WAIS-IV], Digit-Symbol Coding subtest [DSC]) were assessed using analysis of covariance (ANCOVA), controlling for relevant covariates.

RESULTS

Four symptom subtypes were identified in patients with OSA (oxygen desaturation index ≥5 events/hour). Three were similar to prior studies, including the Excessively Sleepy (N=405), Disturbed Sleep (N=382) and Minimally Symptomatic (N=280), and one was a novel subtype in our sample defined as Excessively Sleepy with Disturbed Sleep (N=247). After covariate adjustment, statistically significant differences among subtypes (p=0.037) and among subtypes and patients without OSA (p=0.044) were observed in DSC scores; the Minimally Symptomatic subtype had evidence of higher DSC scores than all other groups, including non-OSA patients. No differences were seen in MoCA or RAVLT.

CONCLUSIONS

Results support the existence of previously identified OSA symptom subtypes of excessively sleepy, disturbed sleep and minimally symptomatic in a clinical sample from Canada. Subtypes were not consistently associated with neurocognitive function across multiple instruments.

Successful management of anesthesia complications in a child with Crouzon syndrome

Crouzon syndrome (CS) is a rare autosomal dominant inherited disorder caused by mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. The disease is characterized by premature fusion of the coronal and sagittal sutures of the skull, resulting in clinical manifestations of midfacial hypoplasia, shallow orbit, maxillary dysplasia, and occasional upper respiratory obstruction. This article presents the case of a child aged 2 years and 7 months with CS scheduled for bilateral tonsillectomy and adenoidectomy. The patient had a difficult procedure of extubation and was reintubated and the tracheal intubation was removed 2 days after surgery. The CS is a rare condition with physical characteristics that can result in difficult airway manipulation. It is important for anesthesiologists to recognize and avoid potential airway complications in the management of such patients through detailed preoperative evaluation and careful observation after surgery to reduce perioperative risks.

Psychotic-like experiences in patients with insomnia or sleep apnea: associations with sleep parameters

OBJECTIVES

There are strong links between sleep and psychotic-like experiences (PLE), such as magical ideations or persecutory ideas. Sleep disturbances seem to play an important role in the occurrence of such symptoms, but studies investigating PLE in patients with sleep disorders are lacking.

METHODS

We studied 24 subjects with insomnia disorder (41 ± 13 years) and 47 participants with obstructive sleep apnea (OSA, 47 ± 11 years) in the sleep laboratory and 33 healthy controls. Sleep in patients with sleep disorders was recorded and scored according to standard criteria of the American Academy of Sleep Medicine. PLE were measured by the Magical Ideation Scale (MIS, short form with 10 items) and by the Peters et al., Delusions Inventory (PDI, 21 items). Additionally, cognitive tests and further psychological self-rating tests such as the Beck Depression Inventory (BDI) and the Pittsburgh Sleep Quality Index (PSQI) were administered.

RESULTS

Patients with insomnia had significantly higher scores of magical and delusional ideations compared to healthy controls. Sleep apnea patients showed a tendency of a higher score of delusional beliefs in comparison to controls. Magical ideations in insomnia subjects were significantly negatively correlated with the number of sleep spindles. In a subgroup of insomnia patients without antidepressants, delusional beliefs were negatively associated with rapid eye movement (REM)-sleep.

CONCLUSIONS

As there are indications that diminutions of sleep spindles are a biomarker for dysfunctional thalamo-cortical circuits underlying the neuropathology of psychosis, we conclude that there might be a sub-group of insomnia patients with fewer sleep spindles which is more vulnerable to developing a psychotic disorder in the future.

Maxillomandibular advancement in edentulous patients as a treatment option for obstructive sleep apnea: report of two cases and a proposed treatment protocol

Obstructive sleep apnea (OSA) is a common disease that often causes debilitating symptoms. In its most severe form, OSA increases the risk of cardiovascular disease and mortality. OSA is characterized by repeated episodes of pharyngeal collapse leading to airway obstruction. The treatment options available in severe cases are limited to continuous positive airway pressure ventilation and maxillomandibular advancement (MMA). OSA is particularly difficult to treat successfully in edentulous patients. Two cases are presented here to illustrate use of MMA in edentulous patients with OSA. Our learning points based on these cases are shared, and a treatment and follow-up protocol is proposed for this specific patient group.

Evaluating the feasibility of implementing a Telesleep pilot program using two-tiered external facilitation

BACKGROUND

Obstructive sleep apnea (OSA) can negatively impact patients' health status and outcomes. Positive airway pressure (PAP) reverses airway obstruction and may reduce the risk of adverse outcomes. Remote monitoring of PAP (as opposed to in-person visits) may improve access to sleep medicine services. This study aimed to evaluate the feasibility of implementing a clinical program that delivers treatment for OSA through PAP remote monitoring using external facilitation as an implementation strategy.

METHODS

Participants included patients with OSA at a Veteran Affairs Medical Center (VAMC). PAP adherence and clinical disease severity on treatment (measured by the apnea hypopnea index [AHI]) were the preliminary effectiveness outcomes across two delivery models: usual care (in-person) and Telehealth nurse-delivered remote monitoring. We also assessed visit duration and travel distance. A prospective, mixed-methods evaluation examined the two-tiered external facilitation implementation strategy.

RESULTS

The pilot project included N = 52 usual care patients and N = 38 Telehealth nurse-delivered remote monitoring patients. PAP adherence and disease severity were similar across the delivery modalities. However, remote monitoring visits were 50% shorter than in-person visits and saved a mean of 72 miles of travel (median = 45.6, SD = 59.0, mode = 17.8, range 5.4-220). A total of 62 interviews were conducted during implementation with a purposive sample of 12 clinical staff involved in program implementation. Weekly external facilitation delivered to both front-line staff and supervisory physicians was necessary to ensure patient enrollment and treatment. Synchronized, "two-tiered" facilitation at the executive and coordinator levels proved crucial to developing the clinical and administrative infrastructure to support a PAP remote monitoring program and to overcome implementation barriers.

CONCLUSIONS

Remote PAP monitoring had similar efficacy to in-person PAP services in this Veteran population. Although external facilitation is a widely-recognized implementation strategy in quality improvement projects, less is known about how multiple facilitators work together to help implement complex programs. Two-tiered facilitation offers a model well-suited to programs where innovations span disciplines, disrupt professional hierarchies (such as those between service chiefs, clinicians, and technicians) and bring together providers who do not know each other, yet must collaborate to improve access to care.

Surgical and Nonsurgical Weight Loss for Patients with Obstructive Sleep Apnea

A strong association exists between excess weight and obstructive sleep apnea (OSA), and most patients with OSA have elevated body mass index. Weight loss is an essential part of treatment for patients with OSA and overweight or obesity. Lifestyle interventions are cornerstones of weight management. However, most patients have difficulty achieving and maintaining clinically significant weight loss with lifestyle interventions alone. Health care providers who treat patients with OSA should be familiar with advanced treatment options for overweight and obesity including antiobesity medications, bariatric surgery, and devices. The future of weight management is a customized, multidisciplinary approach for each patient.

Palatopharyngoplasty and Palatal Anatomy and Phenotypes for Treatment of Sleep Apnea in the Twenty-first Century

Successful palatopharyngoplasty is critical for successful sleep apnea surgery. Traditional uvulopalatopharyngoplasty was primarily excisional, whereas newer techniques, such as expansion sphincterpharyngoplasty, are more reconstructive. Studies of flow dynamics even demonstrate that the effectiveness of maxillofacial surgery is significantly mediated through stiffening and enlargement of the lateral retropalatal and pharyngeal airway. The current modified technique of uvulopalatopharyngoplasty/expansion sphincteroplasty aims to maximize relocation and tension on the palatopharyngeus muscle, opening the retropalatal airway and the palatal genu, and minimizing tension on the final mucosal closure.

Automated sleep apnea detection from cardio-pulmonary signal using bivariate fast and adaptive EMD coupled with cross time-frequency analysis

Sleep apnea is a sleep related pathology in which breathing or respiratory activity of an individual is obstructed, resulting in variations in the cardio-pulmonary (CP) activity. The monitoring of both cardiac (heart rate (HR)) and pulmonary (respiration rate (RR)) activities are important for the automated detection of this ailment. In this paper, we propose a novel automated approach for sleep apnea detection using the bivariate CP signal. The bivariate CP signal is formulated using both HR and RR signals extracted from the electrocardiogram (ECG) signal. The approach consists of three stages. First, the bivariate CP signal is decomposed into intrinsic mode functions (IMFs) and residuals for both HR and RR channels using bivariate fast and adaptive empirical mode decomposition (FAEMD). Second, the features are extracted using time-domain analysis, spectral analysis, and time-frequency domain analysis of IMFs from CP signal. The time-frequency domain features are computed from the cross time-frequency matrices of IMFs of CP signal. The cross time-frequency matrix of each IMF is evaluated using the Stockwell (S)-transform. Third, the support vector machine (SVM) and the random forest (RF) classifiers are used for automated detection of sleep apnea with the features from the bivariate CP signal. Our proposed approach has demonstrated an average sensitivity and specificity of 82.27% and 78.67%, respectively for sleep apnea detection using the 10-fold cross-validation method. The approach has yielded an average sensitivity and specificity of 73.19% and 73.13%, respectively for the subject-specific cross-validation. The performance of the approach was compared with other CPC features used for the detection of sleep apnea.

Sleep-disordered breathing in adolescents with obesity: When does it start to affect cardiometabolic health?

BACKGROUND AND AIMS

Pediatric obesity and sleep-disordered breathing (SDB) are associated with cardiometabolic risk (CMR), but the degree of severity at which SDB affects cardiometabolic health is unknown. We assessed the relationship between the CMR and the apnea-hypopnea index (AHI), to identify a threshold of AHI from which an increase in the CMR is observed, in adolescents with obesity. We also compared the clinical, cardiometabolic and sleep characteristics between adolescents presenting a high (CMR+) and low CMR (CMR-), according to the threshold of AHI.

METHODS AND RESULTS

114 adolescents with obesity were recruited from three institutions specialized in obesity management. Sleep and SDB as assessed by polysomnography, anthropometric parameters, fat mass (FM), glucose and lipid profiles, and blood pressure (BP) were measured at admission. Continuous (MetScore_FM) and dichotomous (metabolic syndrome, MetS) CMR were determined. Associations between MetScore_FM and AHI adjusted for BMI, sex and age were assessed by multivariable analyses. Data of 82 adolescents were analyzed. Multivariable analyses enabled us to identify a threshold of AHI = 2 above which we observed a strong and significant association between CMR and AHI (Cohen's d effect-size = 0.57 [0.11; 1.02] p = 0.02). Adolescents with CMR+ exhibited higher MetScore_FM (p < 0.05), insulin resistance (p < 0.05), systolic BP (p < 0.001), sleep fragmentation (p < 0.01) and intermittent hypoxia than CMR- group (p < 0.0001). MetS was found in 90.9% of adolescents with CMR+, versus 69.4% in the CMR- group (p < 0.05).

CONCLUSIONS

The identification of a threshold of AHI ≥ 2 corresponding to the cardiometabolic alterations highlights the need for the early management of SDB and obesity in adolescents, to prevent cardiometabolic diseases.

CLINICAL TRIALS

NCT03466359, NCT02588469 and NCT01358773.

Does the perigestational exposure to chlorpyrifos and/or high-fat diet affect respiratory parameters and diaphragmatic muscle contractility in young rats?

The perinatal period is characterized by developmental stages with high sensitivity to environmental factors. Among the risk factors, maternal High-Fat Diet (HFD) consumption and early-life pesticide exposure can induce metabolic disorders at adulthood. We established the effects of perigestational exposure to Chlorpyrifos (CPF) and/or HFD on respiratory parameters, sleep apnea and diaphragm contractility in adult rats. Four groups of female rats were exposed starting from 4 months before gestation till the end of lactation period to CPF (1 mg/kg/day vs. vehicle) with or without HFD. Sleep apnea and respiratory parameters were measured by whole-body plethysmography in male offspring at postnatal day 60. Then diaphragm strips were dissected for the measurement of contractility, acetylcholinesterase (AChE) activity, and gene expression. The perigestational exposure to CPF and/or HFD increased the sleep apnea index but decreased the respiratory frequency. The twitch tension and the fatigability index were also increased, associated with reduced AChE activity and elevated mRNA expression of AChE, ryanodine receptor, and myosin heavy chain isoforms. Therefore, the perigestational exposure to either CPF and/or HFD could program the risks for altered ventilatory parameters and diaphragm contractility in young adult offspring despite the lack of direct contact to CPF and/or HFD.

Perioperative myocardial injury risk after elective knee and hip arthroplasty in patients with a high risk of obstructive sleep apnea

BACKGROUND

Myocardial injury after non-cardiac surgery (MINS) occurs in approximately 8-13% of patients and has significant 30-day mortality. Patients with obstructive sleep apnea (OSA) suffer recurrent hypoxemia during sleep and surgical patients with OSA are known to have increased risk of cardiorespiratory complications. We hypothesized that patients at high risk for OSA may have an increased risk of MINS. As a secondary analysis, we assessed rates of postoperative cardiopulmonary complications.

METHODS

Adult patients undergoing elective knee or hip arthroplasty with STOPBANG score ≥ 5 were recruited. MINS was determined by measuring troponin-I on postoperative days 1 and 2.

RESULTS

A total of 82 patients were studied. Only one patient had a positive troponin (MINS rate of 1.2%). The rate of cardiopulmonary complications was low (4.9%) and the 30-day mortality rate for these patients was 0.

CONCLUSION

The incidence of MINS and postoperative cardiopulmonary complications in patients with elective arthroplasty and a high risk of OSA were low.

Sleep Disordered Breathing in Hypertrophic Cardiomyopathy-Current State and Future Directions

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and sleep disordered breathing (SDB) is a treatable risk factor that has been seen to occur concurrently, and is known to propagate mortality and morbidity in a number of cardiovascular disease states including heart failure, and indeed hypertrophic cardiomyopathy. In this review, we summarize past studies that explored the simultaneous occurrence of HCM and SDB, and the pathophysiology of SDB in relation to heart failure, arrhythmias, cardiac ischemia and pulmonary hypertension in HCM. The current therapeutic modalities, with the effect of obstructive sleep apnea (OSA) treatment on HCM, are then discussed along with potential future directions.

TLR2 antagonism attenuates the hippocampal neuronal damage in a murine model of sleep apnea via inhibiting neuroinflammation and oxidative stress

BACKGROUND

Obstructive sleep apnea (OSA) in humans chronically promotes the neuronal damage in the hippocampus. Toll-like receptor 2 (TLR2) is pivotal for the development of numerous hippocampal diseases. Chronic intermittent hypoxia (CIH) is a prominent feature of OSA. Here in our study, the effects of TLR2 antagonism on the neural damage elicited by CIH were examined.

METHODS

Ortho-vanillin (O-vanillin) is an inhibitor of TLR2. Adult male mice were subjected to 8 h of intermittent hypoxia per day with or without O-vanillin for 28 days. Neuronal damage, the number of microglia, the interaction of TLR2 with its adapter protein myeloid differentiation factor 88 (MYD88), the expressions of inflammatory cytokines, and the oxidative stress were observed.

RESULTS

O-vanillin inhibited the increased interaction of TLR2 and MyD88, the activation of NFκB, the aggregation of microglia, the overexpression of proinflammatory agents, the elevation of oxidative stress, and hippocampal neuron cell apoptosis induced by CIH.

CONCLUSIONS

Our experiments indicate that TLR2 antagonism may alleviate the hippocampal neuronal damage caused by CIH via inhibiting neuroinflammation and oxidative stress.

Eustachian tube dysfunction in sleep apnea patients and improvements afforded by continuous positive airway pressure therapy

Introduction

Upper airway resistance may accompany eustachian dysfunction and alter middle ear pressure in patients with obstructive sleep apnea syndrome.

Objective

To investigate effects of obstructive sleep apnea syndrome and continuous positive airway pressure treatment on eustachian tube functions.

Methods

Forty-two mild obstructive sleep apnea syndrome patients, 45 moderate obstructive sleep apnea syndrome patients, 47 severe obstructive sleep apnea syndrome patients with continuous positive airway pressure therapy, 32 severe obstructive sleep apnea syndrome patients without continuous positive airway pressure therapy, and 88 individuals without sleep apnea (controls) were included. Tympanometric parameters of groups were compared.

Results

Right middle ear pressures in mild and moderate obstructive sleep apnea syndrome groups did not differ significantly from that of control group (p = 0.93 and p = 0.55), as was also true of the left middle ear pressures (p = 0.94 and p = 0.86). Right middle ear pressure was significantly higher in severe obstructive sleep apnea syndrome groups than in the control group, as was the left middle ear pressure (p < 0.001). Middle ear pressure (negative) was significantly lower in severe obstructive sleep apnea syndrome patients with continuous positive airway pressure therapy compared to those without (p < 0.001). Right ear type B and C tympanogram frequencies were significantly higher in patients with severe obstructive sleep apnea syndrome without continuous positive airway pressure therapy (12.4%) than in the controls (0%) (p = 0.02). Left ear type B or C tympanogram frequencies were significantly higher in patients with severe obstructive sleep apnea syndrome without continuous positive airway pressure therapy (21.9%) than in the controls (0%) (p = 0.002).

Conclusion

Mild and moderate obstructive sleep apnea syndrome did not affect middle ear pressure but severe obstructive sleep apnea syndrome may increase the (negative) middle ear pressure. In severe obstructive sleep apnea syndrome patients, long-term continuous positive airway pressure therapy may normalize middle ear pressure.