Obstructive sleep apnea: implications for cardiac and vascular disease

Sleep-disordered breathing and lung function abnormalities in adults with congenital heart disease

PURPOSE

Advances in treatment enables most patients with congenital heart diseases (CHD) to survive into adulthood, implying the need to address comorbid conditions in this growing cohort of patients. The aim of this study was to evaluate the prevalence of sleep-disordered breathing (SDB) and lung function abnormalities in patients with adult congenital heart disease (ACHD).

METHODS

Patients with ACHD underwent level 3 sleep testing (Embletta MPR polygraphy) and pulmonary function testing. Results were stratified by the underlying haemodynamic ACHD lesion group.

RESULTS

Patients with ACHD (n = 100) were middle-aged (42.3 ± 14.6 years), 54% male and slightly overweight (BMI 25.9 ± 5.5 kg/m2). Polygraphy revealed a prevalence of sleep apnoea of 39% with 15% of patients presenting with predominantly obstructive apnoeic episodes, while 23% of patients presenting primarily with central sleep apnoea. The distribution of mild, moderate, and severe sleep apnoea in the total study population was 26%, 7% and 6%, respectively. Comparison of apnoea-hypopnoea index, presence of sleep apnoea, and apnoea severity did not offer significant differences between the four ACHD lesion groups (p = 0.29, p = 0.41 and p = 0.18, respectively). Pulmonary function testing revealed obstructive lung disease in 19 of 100 patients. Concomitant chronic obstructive pulmonary disease and obstructive sleep apnoea were diagnosed in 3% of patients and were associated with profound nocturnal desaturation.

CONCLUSION

The findings suggest a mild propensity amongst patients with ACHD to develop SDB that seems to be unaffected by the specific underlying congenital lesion.

Prediction of the Sleep Apnea Severity Using 2D-Convolutional Neural Networks and Respiratory Effort Signals

The high prevalence of sleep apnea and the limitations of polysomnography have prompted the investigation of strategies aimed at automated diagnosis using a restricted number of physiological measures. This study aimed to demonstrate that thoracic (THO) and abdominal (ABD) movement signals are useful for accurately estimating the severity of sleep apnea, even if central respiratory events are present. Thus, we developed 2D-convolutional neural networks (CNNs) jointly using THO and ABD to automatically estimate sleep apnea severity and evaluate the central event contribution. Our proposal achieved an intraclass correlation coefficient (ICC) = 0.75 and a root mean square error (RMSE) = 10.33 events/h when estimating the apnea-hypopnea index, and ICC = 0.83 and RMSE = 0.95 events/h when estimating the central apnea index. The CNN obtained accuracies of 94.98%, 79.82%, and 81.60% for 5, 15, and 30 events/h when evaluating the complete apnea hypopnea index. The model improved when the nature of the events was central: 98.72% and 99.74% accuracy for 5 and 15 events/h. Hence, the information extracted from these signals using CNNs could be a powerful tool to diagnose sleep apnea, especially in subjects with a high density of central apnea events.

Obstructive Sleep Apnea - Influence on the Cardiovascular System and Cognition

Kardiovaskuläre und kognitive Erkrankungen sind ebenso wie die obstruktive Schlafapnoe sehr häufige Krankheiten mit einer erheblichen Beeinträchtigung der Lebensqualität und einer deutlichen sozioökonomischen Bedeutung. Die Auswirkungen einer unbehandelten obstruktiven Schlafapnoe (OSA) auf das kardiovaskuläre und kognitive Erkrankungsrisiko und die Therapieeffekte einer OSA sind für die meisten kardiovaskulären und kognitiven Folgeerkrankungen wissenschaftlich nachgewiesen. Für die klinische Praxis besteht ein deutlicher Bedarf nach mehr Interdisziplinarität. Aus schlafmedizinischer Sicht müssen bei der Therapieindikation das individuelle kardiovaskuläre und kognitive Risiko berücksichtigt und kognitive Erkrankungen bei der Beurteilung der Therapieintoleranz und residuellen Symptomatik beachtet werden. Aus internistischer Sicht sollte bei Patienten mit schlecht einstellbarem Hypertonus, Vorhofflimmern, koronarer Herzkrankheit und Schlaganfall die Abklärung einer OSA in die Diagnostik integriert werden. Bei Patienten mit milder kognitiver Beeinträchtigung, Alzheimer-Krankheit und Depression können sich die typischen Symptome wie Fatigue, Tagesmüdigkeit und Reduktion der kognitiven Leistungen mit OSA-Symptomen überschneiden. Die Diagnostik einer OSA sollte in die Abklärung dieser Krankheitsbilder integriert werden, da eine Therapie der OSA die kognitiven Beeinträchtigungen reduzieren und die Lebensqualität verbessern kann.

Patients with obstructive sleep apnea are at great risk of flavor disorders: a 15-year population-based cohort study

OBJECTIVE

Obstructive sleep apnea (OSA) results from upper airway remodeling, which has been suggested to alter sensory and motor neuron function due to hypoxia or snore vibration. This study investigated whether OSA was associated with the risk of flavor disorder (FD).

MATERIALS AND METHODS

Seven thousand and eight hundred sixty-five patients with OSA and 7865 propensity score-matched controls without OSA were enrolled between 1999 and 2013 through a nationwide cohort study. The propensity score matching was based on age, sex, comorbidities including hypertension, hyperlipidemia, chronic obstructive pulmonary disease (COPD), asthma, ankylosing spondylitis, and Charlson comorbidity index, and co-medications during the study period, including statins and angiotensin-converting enzyme (ACE) inhibitors. The adjusted hazard ratio (aHR) of incident FD following OSA was derived using a Cox proportional hazard model. A log-rank test was used to evaluate the time-dependent effect of OSA on FD. Age, sex, comorbidities, and co-medications were stratified to identify subgroups susceptible to OSA-associated FD.

RESULTS

Patients with OSA were at a significantly great risk of FD (aHR = 1.91, 95% CI = 1.08-3.38), which was time-dependent (log-rank test p = 0.013). Likewise, patients with hyperlipidemia were at a significant great risk of FD (aHR = 2.99, 95% CI = 1.33-6.69). Subgroup analysis revealed that female patients with OSA were at higher risks of FD (aHR = 2.39, 95%CI = 1.05-5.47).

CONCLUSIONS

Patients with OSA were at significantly great risk of incident FD during the 15-year follow-up period, especially in female patients with OSA.

CLINICAL RELEVANCE

Timely interventions for OSA may prevent OSA-associated FD.

Role of Oxidative Stress and Inflammation in Insomnia Sleep Disorder and Cardiovascular Diseases: Herbal Antioxidants and Anti-inflammatory Coupled with Insomnia Detection using Machine Learning

Insomnia is well-known as trouble in sleeping and enormously influences human life due to the shortage of sleep. Reactive Oxygen Species (ROS) accrue in neurons during the waking state, and sleep has a defensive role against oxidative damage and dissipates ROS in the brain. In contrast, insomnia is the source of inequity between ROS generation and removal by an endogenous antioxidant defense system. The relationship between insomnia, depression, and anxiety disorders damages the cardiovascular systems' immune mechanisms and functions. Traditionally, polysomnography is used in the diagnosis of insomnia. This technique is complex, with a long time overhead. In this work, we have proposed a novel machine learning-based automatic detection system using the R-R intervals extracted from a single-lead electrocardiograph (ECG). Additionally, we aimed to explore the role of oxidative stress and inflammation in sleeping disorders and cardiovascular diseases, antioxidants' effects, and the psychopharmacological effect of herbal medicine. This work has been carried out in steps, which include collecting the ECG signal for normal and insomnia subjects, analyzing the signal, and finally, automatic classification. We used two approaches, including subjects (normal and insomnia), two sleep stages, i.e., wake and rapid eye movement, and three Machine Learning (ML)-based classifiers to complete the classification. A total number of 3000 ECG segments were collected from 18 subjects. Furthermore, using the theranostics approach, the role of mitochondrial dysfunction causing oxidative stress and inflammatory response in insomnia and cardiovascular diseases was explored. The data from various databases on the mechanism of action of different herbal medicines in insomnia and cardiovascular diseases with antioxidant and antidepressant activities were also retrieved. Random Forest (RF) classifier has shown the highest accuracy (subjects: 87.10% and sleep stage: 88.30%) compared to the Decision Tree (DT) and Support Vector Machine (SVM). The results revealed that the suggested method could perform well in classifying the subjects and sleep stages. Additionally, a random forest machine learning-based classifier could be helpful in the clinical discovery of sleep complications, including insomnia. The evidence retrieved from the databases showed that herbal medicine contains numerous phytochemical bioactives and has multimodal cellular mechanisms of action, viz., antioxidant, anti-inflammatory, vasorelaxant, detoxifier, antidepressant, anxiolytic, and cell-rejuvenator properties. Other herbal medicines have a GABA-A receptor agonist effect. Hence, we recommend that the theranostics approach has potential and can be adopted for future research to improve the quality of life of humans.

Increased diastolic blood pressure and apnea time contribute to the poor apnea and hypopnea index and life quality of primary snoring: a cohort study combined with external validation

Obstructive sleep apnea hypoventilation syndrome (OSAHS) is a common sleep breathing disorder closely associated with cardiovascular disease. However, the respiratory sleep and related cardiovascular parameters on the apnea and hypopnea index (AHI) and life quality of primary snoring are unclear. We launched a cohort study focused on the association between respiratory sleep and cardiovascular-related parameters and apnea and hypopnea index, incorporating data from 218 patients with primary snoring in our medical center between Jun 1, 2015, and Apr 1, 2016. Thirty patients from Sichuan Cancer Hospital were used for validation. Patients with longer apnea time were more likely to progress to higher AHI (> 30) than controls (OR = 5.66, 95% CI = [2.79, 11.97], p < 0.001). Similarly, if patients have a higher value of diastolic blood pressure, they will also have a higher AHI (> 30) (HR [95% CI] = 3.42 [1.14, 13.65], p = 0.043). According to multivariate analysis, longest apnea time, the mean percentage of SaO2, and neckline length were independent risk factors of overall survival. A predictive model developed based on these factors above yielded a favorable agreement (C-index = 0.872) on the calibration curve. Thirty patients conducted external validation from Sichuan Cancer Hospital, displaying an AUC of 0.833 (0.782-0.884). Increased diastolic blood pressure and apnea time affect AHI level. An AHI prediction model based on these factors above can help clinicians predict the risk of high AHI events.

The Need for Social and Environmental Determinants of Health Research to Understand and Intervene on Racial/Ethnic Disparities in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA), a sleep-disordered breathing (SDB) disorder, affects at least 25 million adults in the United States and is associated with increased risk for hypertension, diabetes, and cardiovascular disease (CVD). Racial/ethnic minorities have a disproportionate burden of OSA along with the health sequelae associated with this condition. Despite supporting evidence of racial/ethnic disparities, few studies have investigated SDB including OSA among minoritized racial/ethnic groups. In this scoping review of the literature, the authors summarize current findings related to racial/ethnic disparities in OSA, identified social and environmental determinants of health, treatment inequities, and promising evidence-based interventions and conclude with future research directions.

Study on Mechanism of Invigorating Qi and Promoting Blood Circulation in Treatment of Angiogenesis after Myocardial Infarction Using Network Pharmacology

Objective

This article aims to explore the impact and mechanism of invigorating qi and promoting blood circulation (IQPBC) on angiogenesis after myocardial infarction (AMI) by using network pharmacology approach.

Methods

First, IQPBC was searched on the traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP), and the main active ingredients and targets of IQPBC were screened and obtained. Second, by virtue of GeneCards and Online Mendelian Inheritance in Man (OMIM) databases, the targets related to AMI are screened and then obtained. Then, the intersection targets between IQPBC and AMI can be obtained by using online tool Venny 2.1.0. Third, based on the STRING database, the interaction of target proteins is established and some key targets can be analyzed and obtained. Finally, the IQPBC-AMI interaction network is constructed by using Cytoscape, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses are executed by DAVID and OmicShare databases.

Results

143 intersection targets between IQPBC and AMI are obtained. Besides, key active ingredients, namely, quercetin, tanshinone, kaempferol, and luteolin, are shown. Furthermore, AKT1, VEGFA, STAT3, HIF-1α, and other 10 key targets are obtained. A total of 752 enrichment results are acquired by using GO analysis. KEGG pathway enrichment analysis shows 241 signaling pathways, focusing on cancer, fluid shear stress and atherosclerosis, and TNF and PI3K/AKT signaling pathways.

Conclusion

This article studies the potential targets and signaling pathways of IQPBC drugs acting on AMI via the network pharmacology approach, which better illustrates the effect and mechanism, and provides some good ideas for the following mechanism research studies.

Sleep Disorders and Psoriasis: An Update

Psoriasis alters patients’ quality of life. Among the disorders associated with psoriasis, sleep disorders are common, although they are not directly assessed by most quality-of-life scores. Thus, the specific evaluation of sleep disorders using dedicated scores is necessary, especially because such disorders alter patients;’ physical and psychological health. The relationship between psoriasis and sleep disorders has been shown in numerous studies, but has not yet been fully elucidated. The aim of this study was to update knowledge of sleep disorders in patients with psoriasis, through a review of the scientific literature since 1980. This work covers several topics of interest, such as sleep assessment methods, the prevalence of sleep disorders in patients with psoriasis, factors predictive of sleep disorders in patients with psoriasis, the impact of sleep disorders on comorbidities and quality of life, pathogenic mechanisms, obstructive sleep apnoea and restless leg syndromes, and the impact of biotherapy treatments on sleep disorders in patients with psoriasis.

Angiotensin II receptor blocker irbesartan attenuates sleep apnea-induced cardiac apoptosis and enhances cardiac survival and Sirtuin 1 upregulation

BACKGROUND

The purpose of this study was to investigate whether or not angiotensin II type 1 receptor blocker irbesartan (ARB) with a partial agonist of PPAR-γ could protect against chronic nocturnal intermittent hypoxia (CIH)-induced cardiac Fas/FasL-mediated to mitochondria-mediated apoptosis.

METHODS

Sprague-Dawley rats were in a normoxic control group (CON-G), or rats were in a chronic nocturnal intermittent hypoxia group (HP-G, from 3 to 7% oxygen versus 21% oxygen per forty seconds cycle, nocturnally 8 h per day for 1 month), or rats were in a chronic nocturnal intermittent hypoxia group pretreated with ARB (50 mg/kg/day, S.C.) (ARB-HP-G). Echocardiography, H&E staining, TUNEL staining, and Western blotting were measured in the left ventricle.

RESULTS

Hypoxia-induced SIRT1 degradation, Fas receptors, FADD, active caspase-8 and caspase-3 (Fas/FasL apoptotic pathway) and Bax, tBid, active caspase-9 and -3 (mitochondrial apoptotic pathway) and TUNEL-positive apoptosis were reduced in ARB-HP-G when compared with HP-G. IGF-I, IGF1 receptor, p-PI3k, p-Akt, Bcl2, and Bcl-XL (IGF1/PI3K/AKT pro-survival pathway) were increased in ARB-HP-G compared to HP-G.

CONCLUSIONS

Our findings suggest that the ARB may prevent cardiac Fas/FasL to mitochondrial apoptotic pathways and enhance cardiac IGF1/PI3K/AKT pro-survival pathway in the sleep apnea model associated with JNK de-activation and SIRT1 upregulation. ARB prevents chronic sleep apnea-enhanced cardiac apoptosis via enhancing survival pathways.

Positionspapier „Schlafmedizin in der Kardiologie“, Update 2021

Es hat sich viel getan in der Welt der Schlafmedizin in der Kardiologie, weshalb eine vollwertige Überarbeitung des Positionspapiers „Schlafmedizin in der Kardiologie“ erforderlich wurde. In der aktuellen neuartigen Version finden sich nicht nur alle verfügbaren Studien, Literaturstellen und Updates zu Pathophysiologie, Diagnostik- und Therapieempfehlungen, sondern auch Ausblicke auf neue Entwicklungen und zukünftige Forschungserkenntnisse. Dieses überarbeitete Positionspapier gibt Empfehlungen für Diagnostik und Therapie von Patienten mit kardiovaskulären Erkrankungen mit schlafassoziierten Atmungsstörungen und erteilt darüber hinaus einen fundierten Überblick über verfügbare Therapien und Evidenzen, gibt aber ebenso Ratschläge wie mit Komorbiditäten umzugehen ist. Insbesondere enthält dieses überarbeitete Positionspapier aktualisierte Stellungnahmen zu schlafassoziierten Atmungsstörungen bei Patienten mit koronarer Herzerkrankung, Herzinsuffizienz, arterieller Hypertonie, aber auch für Patienten mit Vorhofflimmern. Darüber hinaus finden sich erstmals Empfehlungen zur Telemedizin als eigenes, neues Kapitel. Dieses Positionspapier bietet Kardiologen sowie Ärzten in der Behandlung von kardiovaskulären Patienten die Möglichkeit einer evidenzbasierten Behandlung der wachsend bedeutsamen und mit zunehmender Aufmerksamkeit behafteten Komorbidität schlafassoziierter Atmungsstörungen. Und nicht zuletzt besteht mit diesem neuen Positionspapier eine enge Verknüpfung mit dem neuen Curriculum Schlafmedizin der Deutschen Gesellschaft für Kardiologie, weshalb dieses Positionspapier eine Orientierung für die erworbenen Fähigkeiten des Curriculums im Umgang von kardiovaskulären Patienten mit schlafassoziierten Atmungsstörungen darstellt.

Does continuous positive airway pressure therapy benefit patients with coronary artery disease and obstructive sleep apnea? A systematic review and meta-analysis

The prevalent co‐morbidity of coronary artery disease (CAD) and obstructive sleep apnea (OSA) has attracted great interest. However, effects of continuous positive airway pressure (CPAP) in patients with OSA and CAD for cardiovascular outcomes and deaths are still controversial. Usage of CPAP among patients with CAD and OSA could decrease the risk of cardiovascular events and death in adults. PubMed, EMBASE, Web of science, and Cochrane Library were systematically searched. Studies that described association of CPAP treatment with cardiovascular events in CAD and OSA patients were included. The main outcome was the major adverse cardiovascular events (MACE), including all‐cause death, cardiovascular death, myocardial infarction (MI), stroke, and repeat revascularization. Summary relative risks (risk ratios [RRs]) and 95% confidence intervals (CIs) of outcomes were pooled and heterogeneity was assessed with the I² statistic. Nine studies enrolling 2590 participants with OSA and CAD were included and extracted data. There was significant association of CPAP with reduced risk of MACE (RR, 0.73, 95% CI [0.55, 0.96]), particularly among those with AHI less than 30 events/h (RR, 0.43, 95% CI [0.22, 0.84]). Similarly, the same result was found in all‐cause death (RR, 0.66, 95% CI, [0.46, 0.94]) and cardiovascular death (RR, 0.495, 95% CI [0.292, 0.838]). Our data suggested that CPAP usage, compared to usual care, was associated with reduced risks of cardiovascular outcomes or death in patients with OSA and CAD, particularly in the subgroup with AHI less than 30 events/h, which still needs further studies to confirm.

Association Between Obstructive Sleep Apnea and Metabolic Abnormalities in Patients With Hypertrophic Cardiomyopathy

OBJECTIVES

Metabolic abnormalities have been associated with long-term cardiac mortality in patients with hypertrophic cardiomyopathy (HCM). Obstructive sleep apnea (OSA) is a risk factor for metabolic abnormalities in general populations, but association between OSA and metabolic abnormalities in HCM is still undefined. This study aimed to investigate the relationship between OSA and metabolic dysfunction in a large series of patients with HCM.

METHODS

A total of 587 patients with HCM who underwent sleep evaluations at Fuwai Hospital were included. Data from clinical characteristics, polysomnography studies, and metabolic measurements were collected.

RESULTS

OSA was present in 344 patients (58.6%). Patients with OSA were older, more often male, and had more clinical comorbidities. Body mass index, blood pressure, fasting glucose, and triglycerides all increased (all P < 0.001) and high-density lipoprotein cholesterol decreased (P = 0.046) with the severity of OSA. In multivariate analysis, moderate to severe OSA and Log (apnea-hypopnea index + 1) were independently associated with obesity (odds ratio [OR], 2.42; 95% CI, 1.48-3.95 and OR, 1.60; 95% CI, 1.31-1.95), elevated blood pressure (OR, 1.99; 95% CI, 1.42-3.26 and OR, 1.31; 95% CI, 1.08-1.60), and elevated triglycerides (OR, 1.71; 95% CI, 1.05-2.78 and OR, 1.24; 95% CI, 1.02-1.51 but not elevated fasting glucose (OR, 0.88; 95% CI, 0.50-1.52 and OR, 1.02; 95% CI, 0.82-1.28) or reduced high-density lipoprotein cholesterol (OR, 1.30; 95% CI, 0.83-2.04 and OR, 1.06; 95% CI, 0.89-1.27).

CONCLUSIONS

Severity of OSA is independently associated with some profiles of metabolic abnormalities. Clinical trials are required to determine whether OSA treatment improves metabolic abnormalities and long-term outcomes in patients with HCM.

Sleep Apnea and Atrial Fibrillation: Role of the Cardiac Autonomic Nervous System

Sleep apnea is highly associated with atrial fibrillation (AF), and both diseases are highly prevalent in the United States. The mechanistic underpinnings that contribute to their association remain uncertain, but numerous possible mechanisms have been proposed, including dysfunction of the cardiac autonomic nervous system (ANS). Studies have reported that apnea induces hyperactivity of the ANS, leading to increases in AF susceptibility. This review compiles the latest evidence on the role of the ANS in sleep-apnea-induced AF.

The Converging Pathologies of Obstructive Sleep Apnea and Atrial Arrhythmias

Obstructive sleep apnea (OSA) is highly prevalent in the United States (US). Along with epidemic rates of obesity, the rate of OSA cases is also on the rise. OSA is associated with multiple chronic health conditions, including hypertension, diabetes, stroke, myocardial ischemia, and heart rhythm disturbances. OSA is commonly treated with continuous positive airway pressure (CPAP) therapy. Several reports indicate that effective treatment of OSA can reduce the risk of cardiovascular diseases, including cardiac arrhythmias, especially atrial fibrillation (AF). CPAP therapy helps to maintain sinus rhythm after interventions such as electrical cardioversion and catheter ablation in patients with AF. However, more data is required to establish a relationship between OSA and other atrial arrhythmias as well to evaluate the effect of CPAP. This review will compile the latest evidence on the pathophysiology, management, and treatment of atrial arrhythmias associated with OSA.

Association between severity of obstructive sleep apnea and high-sensitivity C-reactive protein in patients with hypertrophic obstructive cardiomyopathy

Background

Obstructive sleep apnea (OSA) is highly prevalent in patients with hypertrophic obstructive cardiomyopathy (HOCM). Inflammatory responses are increased in patients with OSA, meanwhile, inflammation is also associated with adverse outcomes in HOCM.

Hypothesis

To investigate the association between severity of OSA and high‐sensitivity C‐reactive protein (hs‐CRP) in patients with HOCM.

Methods

Three hundred and ninteen patients with HOCM who underwent sleep evaluations at Fuwai Hospital were retrospectively included between February 2010 and December 2018. Data from baseline clinical characteristics and polysomnography studies were collected.

Results

OSA was present in 168 (52.7%). Patients with OSA were older, more likely to be male, had a higher body mass index and more clinical comorbidities. Patients with OSA had enlarged left ventricular diameter and similar left ventricular outflow tract obstruction compared with those without. In multivariate logistic analysis, apnea‐hypopnea index (OR, 1.024; 95% CI, 1.005‐1.044; P = .014), oxygen desaturation index (OR, 1.025; 95% CI, 1.004‐1.046; P = .018) and lowest oxygen saturation (OR, 0.951; 95% CI, 0.915‐0.989; P = .011) were independently associated with high risk hs‐CRP (>3 mg/L) after adjusting for confounders. In addition, decreasing lowest oxygen saturation (β = −.159, P = .004) was also independently correlated with increasing hs‐CRP concentrations in multivariate linear analysis after adjusting for confounders.

Conclusions

Severity of OSA was independently associated with elevated hs‐CRP levels in patients with HOCM. Further studies are needed to evaluate the effects of treating OSA on hs‐CRP as well as clinical outcomes in these patients.

The relationship between risk of obstructive sleep apnea and other sleep problems, depression, and anxiety in adolescents from a community sample

Obstructive sleep apnea (OSA) is highly related to mental health problems, such as depression and anxiety. However, previous studies on OSA and depression and anxiety have mostly been conducted in the adult population. We aimed to (1) screen for risk of OSA in a sample of adolescents from the general population using self-report questionnaires and (2) examine whether there are differences between the high- and low-risk groups for OSA in depressive and anxiety symptoms, self-esteem, and sleep-related variables. The data of 793 students (age range: 12-17 years old) were analyzed. The participants were assigned to the high-risk (n = 202, 25.5%) or the low-risk group (n = 591, 74.5%) of OSA. The participants in the high-risk group had more severe anxiety symptoms, lower self-esteem, insomnia, excessive daytime sleepiness, and higher BMI compared those in the low-risk group. This study shows that it is possible to efficiently screen for risks of various problems associated with OSA in adolescents using an easy and simple screening tool.

Effect of lorcaserin on weight reduction in persons with obstructive sleep apnea (OSA): a combined subgroup analysis from three randomized, controlled clinical trials

STUDY OBJECTIVES

To evaluate weight loss with lorcaserin in persons with obstructive sleep apnea (OSA).

METHODS

This retrospective analysis evaluated weight loss of lorcaserin (10 mg twice daily) versus placebo in persons with obesity or overweight persons with OSA from a pooled database of three randomized, controlled trials. Primary end points were reductions in the baseline body weight of ≥5% and ≥10% at year 1 and overall weight change at year 1. Changes in heart rate and blood pressure were also evaluated.

RESULTS

A total of 336 persons with OSA were identified in the overall pooled population (N = 6,636). At year 1, more patients receiving lorcaserin lost ≥5% (47.2% lorcaserin vs. 25.6% placebo; p < 0.0001) and 10% (22.2% lorcaserin vs. 13.1% placebo; p < 0.0354) of their baseline body weight. Weight loss at year 1 was 6.4 kg versus 3.5 kg in the lorcaserin and placebo groups, respectively (p < 0.0001). Similar results were observed for change in blood pressure and heart rate, with responders having larger benefits. Weight loss was similar between persons with and without OSA.

CONCLUSIONS

In this retrospective analysis, persons with OSA showed significant and meaningful weight loss, blood pressure and heart rate reductions in patients treated with lorcaserin versus placebo. Persons with OSA lost just as much weight as those without OSA. Health care providers can expect persons with OSA to lose weight by diet, exercise and the weight loss medication lorcaserin comparable with persons without OSA. Further prospective research is warranted to evaluate impact of weight loss on OSA and overall outcomes for patients.

Sleep-Disordered Breathing and Idiopathic Normal-Pressure Hydrocephalus: Recent Pathophysiological Advances

Purpose of Review

Idiopathic normal-pressure hydrocephalus (iNPH) is characterized clinically by ventriculomegaly, abnormal gait, falls, incontinence, and cognitive decline. This article reviews recent advances in the pathophysiology of iNPH concerning sleep-disordered breathing (SDB) and glymphatic circulation during deep sleep.

Recent Findings

The authors found iNPH frequently associated with obstructive sleep apnea (OSA). A critical factor in iNPH is intracranial venous hypertension delaying drainage of cerebrospinal fluid (CSF) into the cerebral venous sinuses. CSF-venous blood circulates in the jugular veins and finally drains into the heart. During SDB, repeated reflex attempts to breathe induce strong respiratory efforts against a closed glottis thereby increasing the negative intrathoracic pressure. This causes atrial distortion and decreases venous return to the heart resulting in retrograde intracranial venous hypertension. Additionally, repeated awakenings from OSA impede sleep-associated circulation of interstitial CSF into the glymphatic circulation contributing to hydrocephalus.

Summary

Sleep has become a critical element in the cognitive changes of aging including iNPH.

Sleep Disturbances in Patients With Coronary Heart Disease: A Systematic Review

STUDY OBJECTIVES

Investigation into sleep and coronary heart disease (CHD) has predominantly been focused on sleep disturbances as a risk factor for developing CHD. Objectively measured and self-reported sleep at a patient level has only been sparsely and not systematically reported. Therefore, we set out to review the literature for studies using objectively measured and self-reported sleep in patients with CHD. The review focuses on patients with acute coronary syndrome (ACS) and stable CHD.

METHODS

A systematic review performed in four databases adhering to the PRISMA guidelines applying a qualitative synthesis of evidence.

RESULTS

Following ACS, we found sleep architecture to be significantly disturbed with changes normalizing over a period of up to 6 months. With increasing severity of CHD, sleep disturbances were more pronounced; however, the modulating effects of sleep-disordered breathing and ejection fraction on sleep in patients with CHD are conflicting. Overall, studies were predominantly cross-sectional in design and of low methodological quality. Polysomnography was the predominant outcome assessment tool and validated self-reported assessment tools were limited.

CONCLUSIONS

Future investigations in sleep and CHD applying both a longitudinal design and investigating objective and self-reported sleep assessments are warranted.

SYSTEMATIC REVIEW REGISTRATION

Registry: PROSPERO, Title: Sleep measures in relation to coronary heart disease: a systematic review, Identifier: CRD42017056377, URL: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=56377.

TNFRSF11B: A potential plasma biomarker for diagnosis of obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) was characterized by chronic intermittent hypoxia, which was an independent risk factor for endothelial dysfunction. Circulating TNFRSF11B might play an important role in promoting endothelial cells dysfunction. We explored the role of plasma TNFRSF11B as a potential mechanism of endothelial dysfunction in OSA patients.

METHODS

The study population consisted of 120 patients with varying severity of OSA and 40 control subjects. Plasma TNFRSF11B levels were measured using human Magnetic Luminex assay.

RESULTS

Our data showed that plasma TNFRSF11B levels were significantly higher in patients with OSA. After adjusting confounding factors, plasma TNFRSF11B levels were independently associated with the presence of OSA (Beta:0.434, 95% CI: 664.096 to 1076.247; P < 0.001) and plasma TNFRSF11B levels were positively associated with the apnea-hypopnea index (Beta:0.486, 95% CI: 0.007 to 0.017; P < 0.001). Furthermore, plasma TNFRSF11B showed higher discriminatory accuracy in predicting the presence of OSA (AUC:0.964).

CONCLUSIONS

Plasma TNFRSF11B levels were significantly associated with the presence of OSA and its severity. TNFRSF11B could be a plasma biomarker with a positive diagnostic value for premature vascular endothelial dysfunction in patients with OSA.

The association of hemocyte profile and obstructive sleep apnea

BACKGROUND

The hemocyte profile is one of the most frequently requested clinical laboratory tests. However, the analysis of blood cell indexes of obstructive sleep apnea (OSA) patients in previous studies was not comprehensive. And, this study aimed to fully analyze the blood routine in OSA patients.

METHODS

A retrospective study was conducted on 1087 male patients, who were admitted to the sleep center of Nanfang Hospital from May 2013 to February 2018. According to the apnea hypopnea index (AHI), patients were divided into four groups: control group (AHI < 5, n = 135), mild OSA (5 ≦ AHI < 15, n = 185), moderate OSA (15 ≦ AHI < 30, n = 171), and severe OSA (AHI ≧ 30, n = 596). Data collected included sleep parameters, complete blood routine, body mass index (BMI), age, and comorbidities.

RESULTS

In our study, leukocytes, neutrophils, lymphocytes, monocytes, eosinophils, basophils, erythrocytes, hemoglobin, hematocrit, platelets, MPV, and PDW-SD were statistically significant among the four groups based on AHI (P < 0.05), but no significant differences were found in MCV, RDW-SD, N/L, and P/L ratio (P > 0.05). Neutrophils, lymphocytes, monocytes, eosinophils, basophils, hemoglobin, hematocrit, platelets, and MPV were significantly correlated with AHI. Moreover, multiple linear regression analysis demonstrated that hematocrit (β = 73.254, P = 0.001), neutrophils (β = 1.414, P = 0.012), and lymphocytes (β = 4.228, P < 0.001) were independently associated with AHI.

CONCLUSION

Neutrophils, lymphocytes, and hematocrit were independently associated with OSA severity. And combining these three blood cell indicators could contribute to the diagnosis of OSA.

Multiclass classification of obstructive sleep apnea/hypopnea based on a convolutional neural network from a single-lead electrocardiogram

OBJECTIVE

In this paper, we propose a convolutional neural network (CNN)-based deep learning architecture for multiclass classification of obstructive sleep apnea and hypopnea (OSAH) using single-lead electrocardiogram (ECG) recordings. OSAH is the most common sleep-related breathing disorder. Many subjects who suffer from OSAH remain undiagnosed; thus, early detection of OSAH is important.

APPROACH

In this study, automatic classification of three classes-normal, hypopnea, and apnea-based on a CNN is performed. An optimal six-layer CNN model is trained on a training dataset (45 096 events) and evaluated on a test dataset (11 274 events). The training set (69 subjects) and test set (17 subjects) were collected from 86 subjects with length of approximately 6 h and segmented into 10 s durations.

MAIN RESULTS

The proposed CNN model reaches a mean [Formula: see text]-score of 93.0 for the training dataset and 87.0 for the test dataset.

SIGNIFICANCE

Thus, proposed deep learning architecture achieved a high performance for multiclass classification of OSAH using single-lead ECG recordings. The proposed method can be employed in screening of patients suspected of having OSAH.

Environmental Determinants of Insufficient Sleep and Sleep Disorders: Implications for Population Health

PURPOSE OF REVIEW

Sleep is important for overall health and well-being. Insufficient sleep and sleep disorders are highly prevalent among adults and children and therefore a public health burden, particularly because poor sleep is associated with adverse health outcomes. Emerging evidence has demonstrated that environmental factors at the household- and neighborhood-level can alter healthy sleep. This paper will (1) review recent literature on the environmental determinants of sleep among adults as well as children and adolescents; and (2) discuss the opportunities and challenges for advancing research on the environment and sleep.

RECENT FINDINGS

Epidemiologic research has shown that social features of environments, family, social cohesion, safety, noise, and neighborhood disorder can shape and/or impact sleep patterns; and physical features such as light, noise, traffic, pollution, and walkability can also influence sleep and is related to sleep disorders among adults and children. Prior research has mainly measured one aspect of the environment, relied on self-reported sleep, which does not correlate well with objective measures, and investigated cross-sectional associations. Although most studies are conducted among non-Hispanic white populations, there is growing evidence that indicates that minority populations are particularly vulnerable to the effects of the environment on insufficient sleep and sleep disorders.

SUMMARY

There is clear evidence that environmental factors are associated with insufficient sleep and sleep disorders. However, more research is warranted to evaluate how and which environmental factors contribute to sleep health. Interventions that target changes in the environment to promote healthy sleep should be developed, tested, and evaluated as a possible pathway for ameliorating sleep health disparities and subsequently health disparities.

Left ventricular strain rate is reduced during voluntary apnea in healthy humans

During an apneic event, sympathetic nerve activity increases resulting in subsequent increases in left ventricular (LV) afterload and myocardial work. It is unknown how cardiac mechanics are acutely impacted by the increased myocardial work during an apneic event. Ten healthy individuals (23 ± 3 yr) performed multiple voluntary end-expiratory apnea (VEEA) maneuvers exposed to room air, while a subset ( n = 7) completed multiple VEEA exposed to hyperoxic air (100% [Formula: see text]). Beat-by-beat blood pressure, heart rate, and stroke volume were measured continuously. Effective arterial elastance (EA) was calculated as an index of cardiac afterload, and myocardial work was calculated as the rate pressure product (RPP). Tissue Doppler echocardiography was used to measure LV tissue velocities, deformation via strain, and strain rate (SR). Systolic blood pressure (Δ18 ± 13 mmHg, P < 0.01), EA (Δ0.13 ± 0.10 mmHg/ml, P < 0.01), and RPP (Δ9 ± 10 beats/min × mmHg 10^-2, P < 0.01) significantly increased with room air VEEA. This occurred in parallel with decreases in peak longitudinal systolic (Δ-0.62 ± 0.41 cm/s, P < 0.01) and early LV filling (Δ-2.81 ± 1.99 cm/s, P < 0.01) myocardial velocities. Longitudinal SR (Δ-0.30 ± 0.32 1/s, P = 0.01) was significantly decreased during room air VEEA. VEEA with hyperoxia did not alter ( P > 0.18) EA or RPP and attenuated the systolic blood pressure response compared with room air. Myocardial velocities and LV strain rate response to VEEA were unchanged ( P = 0.30) with hyperoxia. Consistent with our hypotheses, VEEA-induced increases in EA and myocardial work impact LV mechanics, which may depend, in part, on stimulation of peripheral chemoreceptors. NEW & NOTEWORTHY Transient increases in arterial blood pressure and systemic vascular resistance occur during sleep apnea events and may contribute to the associated daytime hypertension and risk of overt cardiovascular disease. To date, the link between this apnea pressor response and acute changes in left ventricular function remains poorly understood. We demonstrate that in parallel to increases in cardiac afterload a depressed left ventricular systolic function occurs at end apnea.

Association Between Hypercoagulability and Severe Obstructive Sleep Apnea

Importance

Obstructive sleep apnea (OSA) is related to the increased risk of cardiovascular disease. Although the pathogenesis of this association remains unclear, an alteration in coagulability is suspected as a link.

Objective

To investigate the association between the severity of OSA and blood coagulability.

Design, Setting, and Participants

A retrospective cohort study conducted at a tertiary care university hospital evaluated 146 patients with OSA from January 1, 2009, to July 31, 2015. The participants were divided into 4 groups according to the severity of OSA: control, mild, moderate, and severe.

Main Outcomes and Measures

Association between the severity of OSA and coagulation test results, including platelet count, bleeding time, prothrombin time (PT) in seconds and as international normalized ratio (INR), and activated partial thromboplastin time.

Results

Of the 146 patients, 135 (92.5%) were men; mean (SD) age was 34.8 (11.1) years. The control group included 41 (28.1%) patients; mild OSA, 32 (21.9%); moderate OSA, 30 (20.5%); and severe OSA, 43 (29.5%). Significant correlations were found between the apnea-hypopnea index and the PT seconds (Spearman r coefficient, -0.30; 95% CI, -0.44 to -0.14) and PT INR (Spearman r coefficient, -0.30; 95% CI, -0.44 to -0.14). There were significant differences between the OSA severity groups for PT seconds for the control group (mean, 11.26 [0.78] seconds) vs the moderate OSA group (10.74 [0.62] seconds; mean difference [MD], 0.52; 95% CI, 0.27 to 1.01) and the severe OSA group (10.67 [0.77] seconds; MD, 0.59; 95% CI, 0.14 to 1.03). Significant differences were also noted in PT INR between the control group (1.00 [0.07]) vs the moderate OSA group (0.95 [0.05]; MD, 0.04; 95% CI, 0.01 to 0.07) and the severe OSA group (0.94 [0.07]; MD, 0.05; 95% CI, 0.02 to 0.08). However, there was no significant difference between the control and mild OSA groups in PT seconds.

Conclusions and Relevance

These results suggest that patients with moderate to severe OSA have elevated blood coagulability markers compared with healthy individuals, which may contribute to the occurrence of cardiovascular complications.

Tanshinone IIA protects against chronic intermittent hypoxia-induced myocardial injury via activating the endothelin 1 pathway

Tanshinone IIA (Tan IIA) may exert significant protective effects against heart oxidative stress damage in obstructive sleep apnoea (OSA) syndrome. Chronic intermittent hypoxia (CIH)-triggered left ventricular dysfunction is used in a rat model to mimic CIH in OSA patients. 48 rats were randomly divided into three groups: normal control (NC) group, CIH group and CIH+Tan IIA group with 16 rats in each group. At the end of experiment (day 21), the blood pressure, Plasma ET-1 and NO content, hemodynamic indexes, heart histology, myocardial apoptosis as well as the expression of eNOS, ET-1, ET_A receptor and ET_B receptor were compared among different groups. Tan IIA was able to inhibit the increase of blood pressure induced by CIH. Meanwhile, rat cardiac function in Tan IIA group was evaluated by hemodynamic indexes, histopathological examination. Higher ventricular eNOS activity was induced by Tan IIA with a reduction in both ET-1 and ET_A receptor expression. However, Tan IIA largely inhibited the decrease of ET_B receptor expression. This study demonstrated that Tan IIA has the potential to benefit rat heart against CIH via endothelin system.

Preoperatively Screened Obstructive Sleep Apnea Is Associated With Worse Postoperative Outcomes Than Previously Diagnosed Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) affects up to 26% of US adults, is often undiagnosed, and increases perioperative morbidity. We hypothesized that patients screened on the day of surgery as moderate/high risk for OSA (S-OSA) present similar perioperative respiratory complications, hospital use, and mortality than patients with previously diagnosed OSA (D-OSA). Second, we hypothesized that both OSA groups have more respiratory complications than No-OSA patients.

METHODS

The electronic medical database from 1 academic and 2 community hospitals was retrospectively queried to identify adults undergoing nonemergent inpatient surgery (January 1, 2012, to December 31, 2014). Based on the day-of-surgery preoperative assessment and STOP-BANG (Snoring, Tiredness, Observed apnea during sleep, high blood Pressure, Body mass index >35, Age >50 years, thick Neck, Gender male) score, they were classified as D-OSA, S-OSA, or No-OSA. Perioperative respiratory events and interventions, hospital use, and mortality were measured. The primary outcome composite (adverse respiratory events [AREs]) included perioperative hypoxemic events and difficult airway management. Hypoxemic event was defined as peripheral saturation of oxygen (SpO2) <90% by continuous pulse oximetry for ≥3 minutes, or if validated and/or manually entered into the medical chart. Hypoxemia was classified as mild (lowest SpO2 86%-89%) or moderate/severe (lowest SpO2 ≤85%). Secondary outcomes included postoperative respiratory interventions, intensive care unit admission, hospital length of stay, and 30-day and 1-year all-cause mortality. Outcomes were compared using linear and logistic regression analyses.

RESULTS

A total of 28,912 patients were assessed: 3432 (11.9%) D-OSA; 1546 (5.3%) S-OSA; and 23,934 (82.8%) No-OSA patients. At least 1 ARE was present in 68.0% of S-OSA; 71.0% of D-OSA; and 52.1% of No-OSA patients (unadjusted P < .001), primarily ≥1 moderate/severe hypoxemic event after discharge from the postanesthesia care unit (PACU; 39.9% in S-OSA; 39.5% in D-OSA; and 27.1% in No-OSA patients). S-OSA patients compared to D-OSA patients presented lower rates of moderate/severe hypoxemia in the PACU but similar intraoperatively and postoperatively, higher difficult mask ventilation rates, and similar difficult intubation reports. After adjusting for demographic, health, and surgical differences and hospital type, the likelihood of ≥1 ARE was not different in S-OSA and D-OSA patients (adjusted odds ratio 0.90 [99% confidence interval, 0.75-1.09]; P = .15). S-OSA patients compared to D-OSA patients had significantly increased postoperative reintubation, mechanical ventilation, direct intensive care unit admission after surgery, hospital length of stay, and 30-day all-cause mortality.

CONCLUSIONS

Patients classified as S-OSA have similar rates of AREs to D-OSA patients, but increased postoperative respiratory interventions, hospital use, and 30-day all-cause mortality. These worse postoperative outcomes in S-OSA patients than D-OSA patients could reflect the lack of awareness and appropriate management of this bedside S-OSA diagnosis after PACU discharge. Multidisciplinary interventions are needed for these high-risk patients.

A Bayesian neural network approach to compare the spectral information from nasal pressure and thermistor airflow in the automatic sleep apnea severity estimation

In the sleep apnea-hypopnea syndrome (SAHS) context, airflow signal plays a key role for the simplification of the diagnostic process. It is measured during the standard diagnostic test by the acquisition of two simultaneous sensors: a nasal prong pressure (NPP) and a thermistor (TH). The current study focuses on the comparison of their spectral content to help in the automatic SAHS-severity estimation. The spectral analysis of 315 NPP and corresponding TH recordings is firstly proposed to characterize the conventional band of interest for SAHS (0.025-0.050 Hz.). A magnitude squared coherence analysis is also conducted to quantify possible differences in the frequency components of airflow from both sensors. Then, a feature selection stage is implemented to assess the relevance and redundancy of the information extracted from the spectrum of NPP and TH airflow. Finally, a multiclass Bayesian multi-layer perceptron (BY-MLP) was used to perform an automatic estimation of SAHS severity (no-SAHS, mild, moderate, and severe), by the use of the selected spectral features from: airflow NPP alone, airflow TH alone, and both sensors jointly. The highest diagnostic performance was reached by BY-MLP only trained with NPP spectral features, reaching Cohen's κ = 0.498 in the overall four-class classification task. It also achieved 91.3%, 84.9%, and 83.3% of accuracy in the binary evaluation of the 3 apnea-hypopnea index cut-offs (5, 15, and 30 events/hour) that define the four SAHS degrees. Our results suggest that TH sensor might be not necessary for SAHS severity estimation if an automatic comprehensive characterization approach is adopted to simplify the diagnostic process.

Potential Underestimation of Sleep Apnea Severity by At-Home Kits: Rescoring In-Laboratory Polysomnography Without Sleep Staging

STUDY OBJECTIVES

Home sleep apnea testing (HSAT) is increasingly available for diagnosing obstructive sleep apnea (OSA). One key limitation of most HSAT involves the lack of sleep staging, such that the respiratory event index is calculated using the total recording time (TRT) rather than total sleep time (TST).

METHODS

We performed a retrospective analysis of n = 838 diagnostic polysomnography (PSG) nights from our center; n = 444 with OSA (4% rule, apneahypopnea index (AHI) ≥ 5), and n = 394 with AHI < 5. We recalculated the AHI using time in bed (TIB) instead of TST, to assess the predicted underestimation risk of OSA severity.

RESULTS

Of all the patients with OSA, 26.4% would be reclassified as having less severe or no OSA after recalculating the AHI using TIB rather than TST. Of the n = 275 with mild OSA, 18.5% would be reclassified as not having OSA. The risk of underestimation was higher in those with moderate or severe OSA. Of the n = 119 moderate OSA cases, 40.3% would be reclassified as mild, and of the n = 50 severe OSA cases, 36.0% would be reclassified as moderate. Age strongly correlated with the degree of underestimation of the AHI, because age was significantly correlated with time awake during PSG.

CONCLUSIONS

The risk of sleep apnea underestimation is predicted to be substantial in a tertiary sleep center population. Phenotyping errors included risk of falsely negative results (from mild to normal), as well as category errors: moderate or severe moving to mild or moderate severity, respectively. Clinicians should recognize this underestimation limitation, which directly affects diagnostic phenotyping and thus therapeutic decisions.

COMMENTARY

A commentary on this article appears in this issue on page 531.

The effect of MElatonin on Depressive symptoms, Anxiety, CIrcadian and Sleep disturbances in patients after acute coronary syndrome (MEDACIS): study protocol for a randomized controlled trial

BACKGROUND

Depression following acute coronary syndrome (ACS) constitutes a serious and debilitating problem. Approximately one in five patients will develop significant depression following ACS and less severe depressive symptoms are even more frequent. Furthermore, anxiety symptoms and sleep-wake disturbances are frequent. The objective of the MEDACIS trial is to investigate whether prophylactic treatment with melatonin has a preventive effect on depression, depressive and anxiety symptoms, sleep, and circadian disturbances following ACS.

METHODS/DESIGN

"The effect of MElatonin and Depressive symptoms, Anxiety, CIrcadian and Sleep disturbances in patients after acute coronary syndrome" trial (MEDACIS) is a multicenter, double-blinded, placebo-controlled, randomized clinical trial. A total of 240 patients with ACS and no depressive symptoms will be included in the trial for treatment with either 25 mg melatonin or placebo for a 12-week period. Development and severity of depressive symptoms will be evaluated using Major Depression Inventory every 2 weeks with the purpose of investigating the potential preventive effect of melatonin on depressive symptoms.

DISCUSSION

Previously, only selective serotonin reuptake inhibitors (SSRIs) have been investigated in a primary preventive setup in patients following ACS. However, SSRIs are associated with several side effects. An ideal intervention would constitute the highest degree of prevention of depressive symptoms with the lowest risk of side effects. In this regard, melatonin may have advantages due to its low toxicity as well as its proven anxiolytic and hypnotic effects.

TRIAL REGISTRATION

ClinicalTrials.gov, Identifier: NCT02451293 . Registered on 12 May 2015. EudraCT nr. 2015-002116-32.

Obstructive Sleep Apnea: Epidemiology and Portuguese patients profile

INTRODUCTION

Obstructive Sleep Apnea (OSA) is characterized by recurrent episodes of apnea and hypopnea, secondary to collapse of the upper airways during sleep. OSA is frequently associated to cardiovascular complications. In Portugal, its magnitude is unknown.

METHODS

In 2014 a cross-sectional study was performed using the Portuguese General Practitioner (GP) Sentinel Network (Rede Médicos Sentinela). Participants GP reported all OSA cases diagnosed and registered in their lists of users on the 31 December 2013. Frequency of OSA has been estimated by sex and age. OSA patients were also characterized by method of diagnosis, treatment, and underlying conditions. Association between risk factors and severe OSA (odds ratio) was calculated using a logistic regression model adjusting confounding.

RESULTS

Prevalence of OSA on the population aged 25 years or more was 0.89% (95 CI: 0.80-1.00%); it was higher in males 1.47% (95 CI: 1.30-1.67%) and in those aged between 65 and 74 (2.35%). Most had severe OSA (48.4%). Hypertension (75.9%), obesity (74.2%) and diabetes mellitus (34.1%) were the most frequent comorbidities. Being a male (OR: 2.6; 95 CI: 1.2-5.8) and having obesity (OR: 4.0; 95 CI: 1.8-8.6) were associated with an increased risk of severe OSA.

CONCLUSION

Found frequency of OSA was lower than other countries estimates, which may be explained by differences on case definition but can also suggest underdiagnosis of this condition as reported by other authors.

Obstructive Sleep-Disordered Breathing Is More Common than Central in Mild Familial Dysautonomia

STUDY OBJECTIVES

In familial dysautonomia (FD) patients, sleep-disordered breathing (SDB) might contribute to their high risk of sleep-related sudden death. Prevalence of central versus obstructive sleep apneas is controversial but may be therapeutically relevant. We, therefore, assessed sleep structure and SDB in FD-patients with no history of SDB.

METHODS

11 mildly affected FD-patients (28 ± 11 years) without clinically overt SDB and 13 controls (28 ± 10 years) underwent polysomnographic recording during one night. We assessed sleep stages, obstructive and central apneas (≥ 90% air flow reduction) and hypopneas (> 30% decrease in airflow with ≥ 4% oxygen-desaturation), and determined obstructive (oAI) and central (cAI) apnea indices and the hypopnea index (HI) as count of respective apneas/hypopneas divided by sleep time. We obtained the apnea-hypopnea index (AHI4%) from the total of apneas and hypopneas divided by sleep time. We determined differences between FD-patients and controls using the U-test and within-group differences between oAIs, cAIs, and HIs using the Friedman test and Wilcoxon test.

RESULTS

Sleep structure was similar in FD-patients and controls. AHI4% and HI were significantly higher in patients than controls. In patients, HIs were higher than oAIs and oAIs were higher than cAIs. In controls, there was no difference between HIs, oAIs, and cAIs. Only patients had apneas and hypopneas during slow wave sleep.

CONCLUSIONS

In our FD-patients, obstructive apneas were more common than central apneas. These findings may be related to FD-specific pathophysiology. The potential ramifications of SDB in FD-patients suggest the utility of polysomnography to unveil SDB and initiate treatment.

COMMENTARY

A commentary on this article appears in this issue on page 1583.

New Rule-Based Algorithm for Real-Time Detecting Sleep Apnea and Hypopnea Events Using a Nasal Pressure Signal

We developed a rule-based algorithm for automatic real-time detection of sleep apnea and hypopnea events using a nasal pressure signal. Our basic premise was that the performance of our new algorithm using the nasal pressure signal would be comparable to that using other sensors as well as manual annotation labeled by a technician on polysomnography study. We investigated fifty patients with sleep apnea-hypopnea syndrome (age: 56.8 ± 10.5 years, apnea-hypopnea index (AHI): 36.2 ± 18.1/h) during full night PSG recordings at the sleep center. The algorithm was comprised of pre-processing with a median filter, amplitude computation and apnea-hypopnea detection parts. We evaluated the performance of the algorithm a confusion matric for each event and statistical analyses for AHI. Our evaluation achieved a good performance, with a sensitivity of 86.4 %, and a positive predictive value of 84.5 % for detection of apnea and hypopnea regardless of AHI severity. Our results indicated a high correlation with the manually labeled apnea-hypopnea events during PSG, with a correlation coefficient of r = 0.94 (p < 0.0001) and a mean difference of -2.9 ± 11.6 per hour. The proposed new algorithm could provide significant clinical and computational insights to design a PSG analysis system and a continuous positive airway pressure (CPAP) device for screening sleep quality related in patients with sleep apnea-hypopnea syndrome.

Metabolic disturbances: role of the circadian timing system and sleep

The incidence of metabolic disorders such as obesity and diabetes is on the rise, and food quality is not alone to blame. Sleep disturbances, altered feeding time and circadian disruption are linked to metabolic disturbances in many clinical research studies and cross-sectional analyses. This review tried to summarize the role of the circadian timing system and sleep on energy and metabolic homeostasis. We also tried to explain the molecular and endocrine mechanisms behind circadian misalignment and sleep disorders that lead to metabolic disorders.

Sleep Apnea Is Associated with Hearing Impairment: The Hispanic Community Health Study/Study of Latinos

STUDY OBJECTIVE

Sleep apnea (SA) may promote hearing impairment (HI) through ischemia and inflammation of the cochlea. Our objective was to assess an independent association between SA and HI in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) participants.

METHODS

We used data from the HCHS/SOL, a multicenter population-based study of self- identifying Hispanic/Latinos 18- to 74-y-old adults from four US urban communities. We performed home SA testing and in-clinic audiometry testing in all participants. SA was defined as an apnea-hypopnea index (AHI) ≥ 15 events/h. HI was defined as a mean hearing threshold > 25 dB hearing level in either ear at the frequencies: 3,000 to 8,000 Hz for high-frequency HI (HF-HI) and 500 to 2,000 Hz for low-frequency HI (LF-HI). Combined-frequency HI (CF-HI) was defined as both conditions present, and Any-HI was considered as HI in either low or high frequencies.

RESULTS

Of 13,967 participants, 9.9% had SA and 32.3% had Any-HI. Adjusted for risk factors for HI, those with SA had a 30% higher odds of Any-HI (95% confidence interval [CI] = 8% to 57%), 26% higher odds of HF-HI (CI = 3% to 55%), 127% higher odds of LF-HI (CI = 21% to 326%), and 29% higher odds of CF-HI (CI = 0% to 65%). A dose-response association was observed between AHI severity and Any-HI (versus no SA, OR for AHI ≥ 15 and < 30 = 1.22, CI = 0.96 to 1.54, and OR for AHI ≥ 30 = 1.46, CI = 1.11 to 1.91, p = 0.002).

CONCLUSION

SA is associated with HF-HI and LF-HI, independent of snoring and other confounders.

COMMENTARY

A commentary on this article appears in this issue on page 641.

Multiscale entropic assessment of autonomic dysfunction in patients with obstructive sleep apnea and therapeutic impact of continuous positive airway pressure treatment

OBJECTIVE

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular disease because of its associated autonomic nervous and vascular regulatory dysfunctions. We tested the hypothesis that the multiscale entropy (MSE) approach to heart rate variability analysis may be used for evaluating OSA severity through simultaneous assessment of these abnormalities.

METHODS

A total of 147 subjects were divided into four groups according to apnea-hypopnea index (AHI) from polysomnography (PSG): Snoring without OSA (5 > AHI, n = 31), mild (5 ≤ AHI < 15, n = 31), moderate (15 ≤ AHI < 30, n = 41), and severe (AHI ≥ 30, n = 44) OSA. Of the patients, 41 receiving continuous positive airway pressure (CPAP) treatment were included for comparison. For each subject, two segments of electrocardiographic (ECG) signals (both at stage N2) were used for R-R interval (RRI) analysis, including a 10-minute recording 10 minutes after falling asleep (ie, early phase) and another 10-minute segment at 3 hours (ie, late phase). Heart rate variability as reflected in changes in RRI between the two segments was assessed with small-scale multiscale entropy index (MEISS, sum of sample entropy from time scale from 1 to 5) and large-scale multiscale entropy index (MEILS, scale from 6 to 10).

RESULTS

Increase in MEILS in the late phase of sleep was noted in both the normal snoring and CPAP groups (P <0.01). Although the moderate OSA group exhibited MEISS drop in the late phase (P < 0.02), both MEISS and MEILS decreased in the late phase in the severe OSA group (P < 0.001, P < 0.02). However, no differences were noted in mild OSA subjects in both parameters.

CONCLUSION

The results demonstrated significant severity-dependent deterioration in autonomic and vascular regulatory function in patients with OSA as reflected in the reductions in MEISS and MEILS, respectively, and notable improvement after CPAP treatment. The MEI obtainable through PSG may indicate not only OSA severity and physiological status but also therapeutic outcome for OSA patients.

Urinary neutrophil gelatinase-associated lipocalin is associated with heavy metal exposure in welding workers

Metals cause nephrotoxicity with acute and/or chronic exposure; however, few epidemiological studies have examined impacts of exposure to metal fumes on renal injury in welding workers. In total, 66 welding workers and 12 office workers were recruited from a shipyard located in southern Taiwan. Urine samples from each subject were collected at the beginning (baseline) and end of the work week (1-week exposure). Personal exposure to PM_2.5 was measured. The 8-h mean PM_2.5 was 50.3 μg/m³ for welding workers and 27.4 μg/m³ for office workers. iTRAQs coupled with LC-MS/MS were used to discover the pathways in response to welding PM_2.5 in the urine, suggesting that extracellular matrix (ECM)-receptor interactions are a critical mechanism. ECM-receptor interaction-related biomarkers for renal injury, kidney injury molecule (KIM)-1 and neutrophil gelatinase-associated lipocalin (NGAL), were significantly elevated in welding workers post-exposure, as well as were urinary Al, Cr, Mn, Fe, Co, and Ni levels. NGAL was more significantly associated with Al (r = 0.737, p < 0.001), Cr (r = 0.705, p < 0.001), Fe (r = 0.709, p < 0.001), and Ni (r = 0.657, p < 0.001) than was KIM-1, suggesting that NGAL may be a urinary biomarker for welding PM_2.5 exposure. Nephrotoxicity (e.g., renal tubular injury) may be an emerging concern in occupational health.

Positive airway pressure and electrical stimulation methods for obstructive sleep apnea treatment: a patent review (2005 - 2014)

INTRODUCTION

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a major health problem with significant negative effects on the health and quality of life. Continuous positive airway pressure (CPAP) is currently the primary treatment option and it is considered the most effective therapy for OSAHS. Nevertheless, comfort issues due to improper fit to patient's changing needs and breathing gas leakage limit the patient's adherence to treatment.

AREAS COVERED

The present patent review describes recent innovations in the treatment of OSAHS related to optimization of the positive pressure delivered to the patient, methods and systems for continuous self-adjusting pressure during inspiration and expiration phases, and techniques for electrical stimulation of nerves and muscles responsible for the airway patency.

EXPERT OPINION

In the last few years, CPAP-related inventions have mainly focused on obtaining an optimal self-adjusting pressure according to patient's needs. Despite intensive research carried out, treatment compliance is still a major issue. Hypoglossal electrical nerve stimulation could be an effective secondary treatment option when CPAP primary therapy fails. Several patents have been granted focused on selective stimulation techniques and parameter optimization of the stimulating pulse waveform. Nevertheless, there remain important issues to address, like effectiveness and adverse events due to improper stimulation.

Continuous Positive Airway Pressure Treatment Reduces Mortality in Elderly Patients with Moderate to Severe Obstructive Severe Sleep Apnea: A Cohort Study

Obstructive sleep apnea (OSA) is much more prevalent in older people than in middle-aged or young populations, and has been associated with cardiovascular disease. Continuous positive airway pressure (CPAP) is the first-line therapy for OSA, but its long-term clinical benefit in the elderly is unclear. Here, we carried out a prospective cohort study to explore the survival rate and incidence of cardiovascular events in elderly patients with moderate to severe OSA who did or did not receive CPAP treatment. The study included 130 patients (104 male, 26 female; mean age: 77.8 ± 6.2 years) who were followed up for a mean of 5 ± 2.54 years (range, 1–8 years). Thirty-six patients received CPAP and 88 had no CPAP. The results showed that mortality in the untreated group (21.6%) was significantly higher than in the CPAP group (5.6%). Kaplan–Meier survival analysis showed that the survival rate in the CPAP group was 94.4%, which was markedly higher than the rate of 78.4% in the untreated group. The incidence of cardiovascular events was 13.9% in the CPAP group and 55.7% in the untreated group. The present study provides evidence that CPAP can reduce mortality in older patients with moderate to severe OSA, and lead to a good long-term prognosis. The study also indicates that death in older OSA patients is associated with cardiovascular disease and diabetes.

The impact of sleep disorders on glucose metabolism: endocrine and molecular mechanisms

Modern lifestyle has profoundly modified human sleep habits. Sleep duration has shortened over recent decades from 8 to 6.5 hours resulting in chronic sleep deprivation. Additionally, irregular sleep, shift work and travelling across time zones lead to disruption of circadian rhythms and asynchrony between the master hypothalamic clock and pacemakers in peripheral tissues. Furthermore, obstructive sleep apnea syndrome (OSA), which affects 4 - 15% of the population, is not only characterized by impaired sleep architecture but also by repetitive hemoglobin desaturations during sleep. Epidemiological studies have identified impaired sleep as an independent risk factor for all cause of-, as well as for cardiovascular, mortality/morbidity. More recently, sleep abnormalities were causally linked to impairments in glucose homeostasis, metabolic syndrome and Type 2 Diabetes Mellitus (T2DM). This review summarized current knowledge on the metabolic alterations associated with the most prevalent sleep disturbances, i.e. short sleep duration, shift work and OSA. We have focused on various endocrine and molecular mechanisms underlying the associations between inadequate sleep quality, quantity and timing with impaired glucose tolerance, insulin resistance and pancreatic β-cell dysfunction. Of these mechanisms, the role of the hypothalamic-pituitary-adrenal axis, circadian pacemakers in peripheral tissues, adipose tissue metabolism, sympathetic nervous system activation, oxidative stress and whole-body inflammation are discussed. Additionally, the impact of intermittent hypoxia and sleep fragmentation (key components of OSA) on intracellular signaling and metabolism in muscle, liver, fat and pancreas are also examined. In summary, this review provides endocrine and molecular explanations for the associations between common sleep disturbances and the pathogenesis of T2DM.