Obstructive sleep apnoea syndrome as a risk factor for hypertension: population study

Sleep and Cardiovascular Health

Sleep is recognized as a foundational pillar of health, essential for maintaining nearly all vital processes, and a crucial component of cardiovascular function. In recent years, there has been a paradigm shift to conceptualize sleep health as a combination of multiple domains, including duration, timing, quality, variability/regularity, habits/behaviors, and disordered sleep. This review provides a comprehensive overview of the current evidence linking the multifaceted elements that contribute to healthy sleep with cardiovascular and blood pressure-related outcomes. The reviewed literature indicates a strong relationship between sleep and cardiovascular health. However, the specific pathophysiological mechanisms that bridge the various dimensions of sleep with cardiovascular outcomes remain elusive. Given the global burden of cardiovascular disease, understanding the interplay between sleep and cardiovascular health has important implications for both individual and population health. Sustained efforts to move beyond a focus on discrete domains of sleep are essential to fully understand this complex and potentially bidirectional relationship. Promoting healthy sleep patterns and optimizing the management and treatment of sleep disorders are key steps toward developing more comprehensive strategies for reducing cardiovascular risk. Integrating sleep health into routine clinical care is identified as a critical opportunity to enhance cardiovascular disease prevention and management, particularly among vulnerable and high-risk populations.

Long-term effects on blood pressure of soft tissue surgery for obstructive sleep apnea treatment in adults: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis to evaluate long term effect of soft tissue surgery on blood pressure (BP) in adults with obstructive sleep apnea (OSA).

SEARCH METHODS

PubMed, Scopus, the Cochrane library, and Ovid Medline databases were searched through January 2024. Manual searches were also obtained. This review included studies assessing impact of soft tissue surgery for the treatment of OSA in adults on long-term BP.

RESULT

A total of five studies (299 patients) met our inclusion criteria. Pooled random effects analysis demonstrated a statistically significant long-term postoperative reduction of BP, with average systolic BP reduction of 14.04 mmHg [95%CI (-21.97, -6.11); P = 0.0005]. Pooled random effects analysis of data from four studies (277 patients) also demonstrated statistically significant long-term postoperative reduction of diastolic BP by 6.88 mmHg compared with preoperative baseline [95%CI (-13.31, -0.45); P = 0.04].

CONCLUSION

Soft tissue surgery for OSA treatment in adults significantly resulted in long-term blood pressure reduction.

AMI-Sleep: protocol for a prospective study of sleep-disordered breathing/sleep apnoea syndrome and incident cardiovascular events after acute myocardial infarction

INTRODUCTION

Sleep-disordered breathing (SDB) and the related clinical syndrome, sleep apnoea syndrome (SAS), are highly prevalent in patients with ischaemic heart disease and often remain undiagnosed. The AMI-Sleep study will describe its prevalence in patients with acute myocardial infarction (AMI) and assess the independent contribution of the type and severity of SDB/SAS to subsequent incident cardiovascular events and mortality.

METHODS AND ANALYSIS

This prospective study will include patients hospitalised for AMI enrolled in the multicentre nationwide prospective French Cohort of Myocardial Infarction Evaluation (FRENCHIE) registry. A nightly simplified polygraphy is performed before discharge from the index AMI admission, and participants complete two self-administered sleep questionnaires. Baseline data are obtained from the FRENCHIE registry. Each participant will be subsequently followed based on data from the National Health Data System (SNDS). Over a period of 4 years, the AMI-Sleep study is expected to recruit approximately 2000 participants. Assuming at least a 10% rate of incident cardiovascular events over 1 year, there would be an estimated 200 events during the first year of follow-up that would be sufficient in multivariable analysis. The primary objective is to describe the prevalence and severity of SDB in AMI and to analyse the association between the type and severity of SDB (based on the apnoea-hypopnoea index) and the occurrence of cardiovascular events (incident acute coronary syndrome, transient ischaemic attack, stroke) or all-cause death after AMI. Secondary objectives include determining the association between the presence of SAS and coronary artery disease severity, in-hospital mortality, morbidity events, healthcare consumption and related costs.

ETHICS AND DISSEMINATION

Eligible individuals are provided with information about the AMI-Sleep study and provided written informed consent. The protocol was approved by the regional Ethics Committee (CPP Ouest II - Angers, RCB N°2018-A00719-46) on 17 February 2019, is registered on ClinicalTrials.gov (NCT04064593) and started in January 2019 with the expected publication of primary outcome results in 2025.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT04064593.

Combination Drug Therapy with Acetazolamide, Eszopiclone ± Venlafaxine for Obstructive Sleep Apnea (RESCUE-Combo): A Randomized, Double-Blind, Placebo-controlled Clinical Trial

Rationale: Acetazolamide, eszopiclone, and venlafaxine may target different underlying mechanisms of obstructive sleep apnea (OSA) and individually may partially reduce OSA severity in select patients. We tested whether acetazolamide plus eszopiclone (DualRx) reduces OSA severity. We further explored whether the addition of venlafaxine (TripleRx) alleviates OSA in patients who do not fully respond to DualRx. Methods: In this double-blind crossover trial, 20 patients with OSA underwent baseline polysomnography followed by DualRx/placebo phases in random order. Subsequently, 18 patients underwent an open-label TripleRx phase. Each phase lasted 3 days and concluded with polysomnography. The primary outcome was the placebo-adjusted change in apnea-hypopnea index during supine, non-rapid eye movement sleep (AHINREM,supine) from baseline to DualRx. Secondary outcomes included other OSA metrics, sleep parameters, and select clinical outcomes (blood pressure, symptoms, and vigilance). Results: Participants were on average middle aged, overweight, and relatively diverse (20% women, 60% non-White), with severe OSA (median [interquartile range] AHINREM,supine, 32.8 [20 to 48.8] events/h). Compared with placebo, DualRx was well tolerated and improved AHINREM,supine (-13.8 [-24.1 to -5.2] events/h or -45% [-77% to -14%]; PWilcoxon = 0.003), overall AHI, hypoxic burden, and sleep architecture (P < 0.05) but not the selected clinical outcomes. TripleRx did not provide a clear benefit relative to DualRx, although some measures of OSA-related hypoxemia improved more substantially. There were no serious side effects. Conclusions: Short-term use of dual-drug therapy with DualRx substantially reduced OSA severity. Adding venlafaxine did not generally reduce OSA severity but may be beneficial for some patients. Longer term studies are needed to assess effects on clinically important outcomes. Clinical trial registered with www.clinicaltrials.gov (NCT04639193).

Development and Evaluation of a Hypertension Prediction Model for Community-Based Screening of Sleep-Disordered Breathing

Purpose

Approximately 30% of patients with sleep-disordered breathing (SDB) present with masked hypertension, primarily characterized by elevated nighttime blood pressure. This study aimed to develop a hypertension prediction model tailored for primary care physicians, utilizing simple, readily available predictors derived from type IV sleep monitoring devices.

Patients and Methods

Participants were recruited from communities in Guangdong Province, China, between April and May 2021. Data collection included demographic information, clinical indicators, and results from type IV sleep monitors, which recorded oxygen desaturation index (ODI), average nocturnal oxygen saturation (MeanSpO2), and lowest recorded oxygen saturation (MinSpO2). Hypertension was diagnosed using blood pressure monitoring or self-reported antihypertensive medication use. A nomogram was constructed using multivariate logistic regression after Least Absolute Shrinkage and Selection Operator (LASSO) regression identified six predictors: waist circumference, age, ODI, diabetes status, family history of hypertension, and apnea. Model performance was evaluated using area under the curve (AUC), calibration plots, and decision curve analysis (DCA).

Results

The model, developed in a cohort of 680 participants and validated in 401 participants, achieved an AUC of 0.775 (95% CI: 0.730-0.820) in validation set. Calibration plots demonstrated excellent agreement between predictions and outcomes, while DCA confirmed significant clinical utility.

Conclusion

This hypertension prediction model leverages easily accessible indicators, including oximetry data from type IV sleep monitors, enabling effective screening during community-based SDB assessments. It provides a cost-effective and practical tool for prioritizing early intervention and management strategies in both primary care and clinical settings.

Screening moderate to severe obstructive sleep apnea with wearable device

BACKGROUND

Obstructive sleep apnea (OSA) is a highly prevalent sleep-related breathing disorder usually diagnosed through polysomnography (PSG). Moderate to severe OSA can significantly increase morbidity and mortality. Existing screening tools have limited accuracy. This study aimed to evaluate the Wellue O2 ring, a commercial pulse oximeter ring, for screening moderate to severe OSA.

METHODS

A cross-sectional study included adults aged 18 and older suspected of having OSA who underwent PSG while wearing the Wellue O2 ring on their thumb. The oxygen desaturation index (ODI) from both the O2 ring and PSG was recorded. Sensitivity, specificity, and receiver operating characteristic (ROC) curves were calculated to determine the optimal ODI cutoff value for predicting moderate to severe OSA.

RESULTS

The study included 190 participants (53.2% male) with an average age of 43 years and an average apnea-hypopnea index (AHI) of 50.4 events per hour. Among the participants, 84.7% had moderate to severe OSA. The optimal cutoff value for 11% ODI was 1.25 events per hour lasting 20 s, with a sensitivity of 87.30% and a specificity of 78.70%. The area under the ROC curve for identifying moderate to severe OSA was 0.91.

CONCLUSIONS

The Wellue O2 ring demonstrated high accuracy in detecting moderate to severe OSA and could be a viable alternative for screening in clinical settings due to its accessibility and ease of use. However, larger studies are required to validate its clinical utility for diagnosing and managing moderate to severe OSA.

Oxytocin Receptor Polymorphism Is Associated With Sleep Apnea Symptoms

Context

Oxytocin supplementation improves obstructive sleep apnea (OSA), and animal studies suggest involvement of oxytocin in respiratory control. However, the relationship between endogenous oxytocin signaling and human sleep status remains undetermined.

Objective

In this study, we approached the contribution of the intrinsic oxytocin-oxytocin receptor (OXTR) system to OSA by genetic association analysis.

Methods

We analyzed the relationship between OXTR gene polymorphisms and sleep parameters using questionnaire data and sleep measurements in 305 Japanese participants. OSA symptoms were assessed in 225 of these individuals.

Results

The OXTR rs2254298 A allele was more frequent in those with OSA symptoms than in those without (P = .0087). Although total scores on the Pittsburgh Sleep Quality Index questionnaire did not differ between the genotypes, breathlessness and snoring symptoms associated with OSA were significantly more frequent in individuals with rs2254298 A genotype (P = .00045 and P = .0089 for recessive models, respectively) than the G genotype. A multivariable analysis confirmed these genotype-phenotype associations even after adjusting for age, sex, and body mass index in a sensitivity analysis. Furthermore, objective sleep efficiency measured by actigraph was not significantly different between genotypes; however, subjective sleep efficiency was significantly lower in the rs2254298 A genotype (P = .013) compared with the G genotype. The frequency of the A allele is higher in East Asians, which may contribute to their lean OSA phenotype.

Conclusion

The OXTR gene may contribute to OSA symptoms via the respiratory control system, although it could be in linkage disequilibrium with a true causal gene.

Assessing the Pathophysiology, Morbidity, and Mortality of Obstructive Sleep Apnea

The basic definitions of obstructive sleep apnea (OSA), its epidemiology, its clinical features and complications, and the morbidity and mortality of OSA are discussed. Included in this treatise is a discussion of the various symptomatic and polysomnographic phenotypes of COPD that may enable better treatment and impact mortality in persons with OSA. The goal of this article is to serve as a reference for life and disability insurance company medical directors and underwriters when underwriting an applicant with probable or diagnosed sleep apnea. It is well-referenced (133 ref.) allowing for more in-depth investigation of any aspect of sleep apnea being queried.

Association of Snoring and Daytime Sleepiness With Subsequent Incident Hypertension: A Population-Based Cohort Study

BACKGROUND

There is a strong association between obstructive sleep apnea and hypertension, but the effects of obstructive sleep apnea symptoms on the risk of incident hypertension are not well documented. The aim of this prospective study was to examine whether snoring and sleepiness are associated with incident hypertension.

METHODS

Data from the French population-based CONSTANCES cohort were analyzed. Normotensive participants, aged 18 to 69 years, were included between 2012 and 2016 and screened for snoring, morning fatigue, and daytime sleepiness in 2017 using items of the Berlin Questionnaire. We used Cox models, adjusted for multiple potential confounders, including body mass index, baseline blood pressure, sleep duration, and depressive symptoms, to compute hazards ratios of incidentally treated hypertension.

RESULTS

Among 34 727 subjects, the prevalence of self-reported habitual snoring, morning fatigue, and excessive daytime sleepiness (≥3× a week for each) was 23.6%, 16.6%, and 19.1%, respectively. During a median follow-up of 3.1 years (interquartile range, 3.0-3.5), the incidence of treated hypertension was 3.8%. The risk of de novo treated hypertension was higher in participants who reported habitual snoring (adjusted hazard ratio, 1.17 [95% CI, 1.03-1.32]) and excessive daytime sleepiness (adjusted hazard ratio, 1.42 [95% CI, 1.24-1.62]), and increased with the weekly frequency of symptoms, with a dose-dependent relationship (Ptrend≤0.02 for all symptoms).

CONCLUSIONS

Self-reported snoring and excessive daytime sleepiness are associated with an increased risk of developing hypertension. Identification of snoring and daytime sleepiness may be a useful public health screening tool in primary care for hypertension prevention.

Maternal early pregnancy body mass index and risk of sleep apnea in the offspring

STUDY OBJECTIVES

We investigated the association between maternal early pregnancy body mass index (BMI) and offspring sleep apnea diagnosis.

METHODS

We conducted a nationwide cohort study among 3,281,803 singleton live births in Sweden born 1983-2015. Using national registers with prospectively recorded information, we followed participants for a sleep apnea diagnosis from 2 to up to 35 years of age. We compared sleep apnea risks by early pregnancy BMI categories using hazard ratios with 95% confidence intervals from adjusted Cox models. To address confounding by factors shared within families, we conducted sibling-controlled analyses and studied the relation of siblings' maternal BMI with index offspring's sleep apnea risk.

RESULTS

There were 17,830 sleep apnea diagnoses. Maternal early pregnancy BMI was positively associated with offspring sleep apnea risk; compared with women with normal BMI (18.5-24.9), adjusted hazard ratios (95% confidence intervals) of offspring sleep apnea for maternal BMI categories 25.0-29.9 (overweight), 30.0-34.9 (obesity class I), and ≥35.0 (obesity class II or III) were, respectively, 1.14 (1.09, 1.19), 1.28 (1.20, 1.36), and 1.40 (1.27, 1.54). Corresponding hazard ratios from sibling-controlled analyses representing risk change for maternal BMI differences between pregnancies were, respectively, 1.13 (1.01, 1.26), 1.17 (0.97, 1.42), and 1.32 (0.97, 1.80). Hazard ratios by siblings' maternal BMI were attenuated, suggesting a weak role for shared familial factors. Other pregnancy, birth, and neonatal complications were associated with offspring sleep apnea risk but did not substantially mediate the association with maternal obesity.

CONCLUSIONS

Maternal overweight and obesity are associated with offspring sleep apnea risk in a dose-response manner.

CITATION

Zhu MQ, Cnattingius S, O'Brien LM, Villamor E. Maternal early pregnancy body mass index and risk of sleep apnea in the offspring. J Clin Sleep Med. 2024;20(10):1675-1684.

Predictors and markers of the cardiovascular impact of obstructive sleep apnoea

PURPOSE OF REVIEW

Obstructive sleep apnoea (OSA) is the most common form of sleep-disordered breathing and has been linked to cardiovascular health. However, some of the findings supporting this are controversial. These discrepancies might be a result of heterogeneity among OSA patients, and thus, additional information would be required to better stratify OSA patients according to cardiovascular risk. In this review, we aim to discuss the potential of biomarkers to fulfil this role.

RECENT FINDINGS

Randomized controlled trials have been unable to confirm whether OSA treatment with continuous positive airway pressure (CPAP) has a positive effect on cardiovascular outcomes. Emerging physiology-based metrics of OSA seem to be more suitable for identifying patients at higher risk of cardiovascular disease and predicting the effects of CPAP outcomes on cardiovascular health. Similarly, blood-based molecular markers have gained attention in this context over the last few years.

SUMMARY

Accurate cardiovascular risk stratification and appropriate treatment allocation for OSA patients remain challenging. However, significant efforts are being made to develop novel tools to address these important issues.

Ethical and Policy Implications of Racial and Ethnic Healthcare Disparities in Sleep Health

Despite efforts in recent years, including in policy and research, to address health disparities in the United States, many of those disparities continue to fester in marginalized racial/ethnic populations. Understanding sleep health disparities is critical in understanding the health and wellness of these groups. Using obstructive sleep apnea (OSA) in Black populations as a focus, this paper presents the role of race and ethnicity in the clinical understanding of sleep health-related issues by medical practitioners and the implications of the lack of clear policies or best practices to guide medical practitioners' attempts to meet sleep-related needs of marginalized racial/ethnic populations. Furthermore, the knowledge gap may be further complicated by the poor understanding and integration of existing evidence with the many, complex, sleep-associated co-morbidities. Policymaking in this area ought to be based on the ethical implications of disparate sleep-related health outcomes by race and ethnicity. So, we conclude by offering recommendations for developing ethically sound policies for addressing sleep problems in marginalized racial and ethnic populations.

PPARγ Agonist Rosiglitazone and Antagonist GW9662: Antihypertensive Effects on Chronic Intermittent Hypoxia-Induced Hypertension in Rats

The increased incidence of hypertension associated with obstructive sleep apnea (OSA) presents significant physical, psychological, and economic challenges. Peroxisome proliferator-activated receptor gamma (PPARγ) plays a role in both OSA and hypertension, yet the therapeutic potential of PPARγ agonists and antagonists for OSA-related hypertension remains unexplored. Therefore, we constructed a chronic intermittent hypoxia (CIH)-induced hypertension rat model that mimics the pathogenesis of OSA-related hypertension in humans. The model involved administering PPARγ agonist rosiglitazone (RSG), PPARγ antagonist GW9662, or normal saline, followed by regular monitoring of blood pressure and thoracic aorta analysis using staining and electron microscopy. Intriguingly, our results indicated that both RSG and GW9662 appeared to potently counteract CIH-induced hypertension. In silico study suggested that GW9662's antihypertensive effect might mediated through angiotensin II receptor type 1 (AGTR1). Our findings provide insights into the mechanisms of OSA-related hypertension and propose novel therapeutic targets.

Cytosolic Escape of Mitochondrial DNA Triggers cGAS-STING Pathway-Dependent Neuronal PANoptosis in Response to Intermittent Hypoxia

Intermittent hypoxia (IH) is the predominant pathophysiological disturbance in obstructive sleep apnea (OSA), characterized by neuronal cell death and neurocognitive impairment. We focus on the accumulated mitochondrial DNA (mtDNA) in the cytosol, which acts as a damage-associated molecular pattern (DAMP) and activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, a known trigger for immune responses and neuronal death in degenerative diseases. However, the specific role and mechanism of the mtDNA-cGAS-STING axis in IH-induced neural damage remain largely unexplored. Here, we investigated the involvement of PANoptosis, a novel type of programmed cell death linked to cytosolic mtDNA accumulation and the cGAS-STING pathway activation, in neuronal cell death induced by IH. Our study found that PANoptosis occurred in primary cultures of hippocampal neurons and HT22 cell lines exposed to IH. In addition, we discovered that during IH, mtDNA released into the cytoplasm via the mitochondrial permeability transition pore (mPTP) activates the cGAS-STING pathway, exacerbating PANoptosis-associated neuronal death. Pharmacologically inhibiting mPTP opening or depleting mtDNA significantly reduced cGAS-STING pathway activation and PANoptosis in HT22 cells under IH. Moreover, our findings indicated that the cGAS-STING pathway primarily promotes PANoptosis by modulating endoplasmic reticulum (ER) stress. Inhibiting or silencing the cGAS-STING pathway substantially reduced ER stress-mediated neuronal death and PANoptosis, while lentivirus-mediated STING overexpression exacerbated these effects. In summary, our study elucidates that cytosolic escape of mtDNA triggers cGAS-STING pathway-dependent neuronal PANoptosis in response to IH, mainly through regulating ER stress. The discovery of the novel mechanism provides theoretical support for the prevention and treatment of neuronal damage and cognitive impairment in patients with OSA.

Impact of Obstructive Sleep Apnea and Sympathetic Nervous System on Cardiac Health: A Comprehensive Review

A prevalent condition linked to an elevated risk of cardiovascular disease is sleep apnea. This review examines the connections between cardiac risk, the sympathetic nervous system, and sleep apnea. The increased risk of hypertension, arrhythmias, myocardial infarction, and heart failure was highlighted in the pathophysiology of sleep apnea and its effect on sympathetic activation. It is also important to consider potential processes such as oxidative stress, inflammation, endothelial dysfunction, and autonomic imbalance that may relate sleep apnea-induced sympathetic activation to cardiac risk. With implications for creating innovative diagnostic and treatment approaches to lessen the cardiovascular effects of sleep apnea, the goal of this investigation is to improve the understanding of the intricate link between sympathetic activity, cardiac risk, and sleep apnea. This study aimed to clarify the complex relationship between cardiovascular health and sleep apnea by synthesizing the available research and highlighting the crucial role played by the sympathetic nervous system in moderating this relationship. Our thorough investigation may have important therapeutic ramifications that will direct the creation of focused therapies to enhance cardiovascular outcomes in sleep apnea sufferers.

Mandibular advancement devices decrease systolic pressure during the day and night in patients with obstructive sleep apnea: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to analyze whether or not mandibular advancement devices (MADs) produce changes in blood pressure in patients with obstructive sleep apnea (OSA) in relation to use time and if the device is used at night or day.

MATERIALS AND METHOD

A systematic review of the literature and meta-analysis was carried out in accordance with PRISMA guidelines. In the bibliographic search, a total of four databases were consulted: PubMed-Medline, Scopus, Web of Science, and Cochrane. Of the 622 articles initially revealed, 160 duplicates were eliminated. After applying the selection criteria, 17 articles were included for the qualitative analysis and 4 for the meta-analysis. The studies were combined using a random effects model with the inverse method of variance, determining the mean differences in systolic and diastolic pressure before and after treatment using the MAD splint as the effect size. Day/night circadian effect and treatment time were analyzed using meta-regression with a mixed-effects model.

RESULTS

MAD treatment was not found to affect diastolic pressure. By combining the four studies with the control group in a meta-analysis (I2 = 75%; z =  - 0.15; p-value = 0.882), the mean difference in diastolic pressure between the MAD group and the control group was estimated at - 0.06 (- 0.86; 0.74). The meta-regression also showed no significant effect of day/night (p = 0.560) or treatment time (p = 0.854) on diastolic pressure. When combining the four studies with the control group (I2 = 84%%; z =  - 1.47; p-value = 0.142), a non-significant mean difference in systolic pressure between the MAD group and the control group of - 0.99 (- 2.31; 0.33) was estimated in the meta-analysis. However, when assessing the effect of day/night or treatment time on systolic blood pressure using a meta-regression, the latter showed significant covariates that reduce systolic blood pressure values in the model at night (p < 0.001) and in relation to treatment time (p < 0.001).

CONCLUSIONS

Only systolic pressure appears to be affected by the use of the MAD in patients with OSA, and this decrease in systolic pressure is greater at night and when treatment time is longer.

My voyage in the enchanted world of sleep

In this paper, I describe my 45-year career in sleep research. I started my undergraduate studies at Tel Aviv University, where I was first introduced to the enchanted world of sleep, continued to my graduate studies with Wilse B. Webb at the University of Florida, and then to post-doctoral training with Dan Kripke at the University of California at San Diego. Then, I describe the evolution of my academic career at the Technion-Israel Institute of Technology, where I started in 1975 as an Assistant Professor and retired in 2019 as the President of the Institute. I describe the areas of research that I pursued and how the research developed, emphasizing unexpected results that guided me and my lab team in new directions. This includes my early studies on ultradian rhythms, inspired by Nathaniel Kleitman's Basic Rest Activity Cyle hypothesis, utilizing the ultrashort sleep-wake paradigm to chart the 24-hour sleep propensity function, and how these studies led us to explore the role of melatonin in sleep regulation. I also explain why we directed our attention to sleep apnea, and how clinical observations led to the provocative hypothesis that sleep apnea-typically seen as a disorder-may also play a protective role. Under the leadership of my research partner and wife, Lena, we confirmed this hypothesis. Also in this article, I describe my enthusiasm for the history of our field and, as derived from my experience as a Dean of Medicine and President of a university, I share my philosophy about the role of members of academia in society. I emphasize that none of my achievements could have been accomplished without the hard work and motivation of my students and research partners, who shared my enthusiasm and passion for the enchanted world of sleep. This paper is part of the Living Legends in Sleep Research series, which is sponsored by Idorsia Pharmaceuticals and Jazz Pharmaceuticals.

Treatment of Sleep Apnea and Reduction in Blood Pressure: The Role of Heart Rate Response and Hypoxic Burden

BACKGROUND

Obstructive sleep apnea is associated with increased blood pressure (BP). Obstructive sleep apnea treatment reduces BP with substantial variability, not explained by the apnea-hypopnea index, partly due to inadequate characterization of obstructive sleep apnea's physiological consequences, such as oxygen desaturation, cardiac autonomic response, and suboptimal treatment efficacy. We sought to examine whether a high baseline heart rate response (ΔHR), a marker of high cardiovascular risk in obstructive sleep apnea, predicts a larger reduction in post-treatment systolic BP (SBP). Furthermore, we aimed to assess the extent to which a reduction in SBP is explained by a treatment-related reduction in hypoxic burden (HB).

METHODS

ΔHR and HB were measured from pretreatment and posttreatment polygraphy, followed by a 24-hour BP assessment in 168 participants treated with continuous positive airway pressure or nocturnal supplemental oxygen from the HeartBEAT study (Heart Biomarker Evaluation in Apnea Treatment). Multiple linear regression models assessed whether high versus mid (reference) ΔHR predicted a larger reduction in SBP (primary outcome) and whether there was an association between treatment-related reductions in SBP and HB.

RESULTS

A high versus mid ΔHR predicted improvement in SBP (adjusted estimate, 5.8 [95% CI, 1.0-10.5] mm Hg). Independently, a greater treatment-related reduction in HB was significantly associated with larger reductions in SBP (4.2 [95% CI, 0.9-7.5] mm Hg per 2 SD treatment-related reduction in HB). Participants with substantial versus minimal treatment-related reductions in HB had a 6.5 (95% CI, 2.5-10.4) mm Hg drop in SBP.

CONCLUSIONS

A high ΔHR predicted a more favorable BP response to therapy. Furthermore, the magnitude of the reduction in BP was partly explained by a greater reduction in HB.

The association between the effective apnea-hypopnea index and blood pressure reduction efficacy following CPAP/oxygen treatment

BACKGROUND

The effect of sleep apnea treatment on reducing cardiovascular disease risk remains inconclusive. This study aims to assess if the effective apnea hypopnea index (eAHI), a measure of residual sleep apnea burden post-treatment, is a factor in determining blood pressure (BP) response to continuous positive airway pressure therapy. The eAHI integrates time on therapy, residual apnea, and % of sleep time untreated.

METHODS

A secondary analysis of the Heart Biomarker Evaluation in Apnea Treatment (HeartBEAT) study, a randomized, controlled, parallel group assessment of continuous positive airway pressure (CPAP), oxygen and sleep hygiene. The Delta-AHI (▲AHI) was defined as the difference between baseline AHI and effective AHI at 12 weeks. Logistic and linear regression models estimated the predictors for nocturnal systolic BP change following sleep apnea therapy.

RESULTS

One hundred and sixty-nine subjects with a mean age of 62.82 ± 6.99 years were included in the final analysis. Fifty subjects had ▲AHI ≤8/hour of sleep and 119 subjects were higher. After adjustment, baseline mean nighttime systolic blood pressure (OR 1.036, 95% CI 1.015-1.058, p: 0.001) and ▲AHI ≥8/hour (OR 2.406, 95% CI 1.116-5.185, p:0.025) were independent predictors for mean nighttime systolic blood pressure change >3 mm Hg. The higher effective AHI was negatively related with BNP (β: -2.564, SE: 1.167, p: 0.029) and positively related with troponin change (β: 0.703, SE: 0.256, p: 0.007).

CONCLUSION

The ▲AHI was an independent predictor of the blood pressure response to sleep apnea treatment.

REGISTER NUMBER

NCT01086800.

A Comprehensive Review of Solriamfetol to Treat Excessive Daytime Sleepiness

Purpose of Review

This is a comprehensive review of the literature regarding the use of Solriamfetol for excessive daytime sleepiness. It covers the background and current therapeutic approaches to treating excessive daytime sleepiness, the management of common comorbidities, and the existing evidence investigating the use of Solriamfetol for this purpose.

Recent Findings

Excessive daytime sleepiness leads to worse quality of life, a medical sequela and significant economic cost. There are multiple phenotypes of excessive daytime sleepiness depending on the comorbidity making treatment challenging. Due to the complexity of etiology there is not a cure for this ailment. Solriamfetol is a norepinephrine/dopamine dual reuptake antagonist that can be used to manage daytime sleepiness. Solriamfetol was first approved by the FDA in 2018 for use in excessive daytime sleepiness associated with obstructive sleep apnea and narcolepsy. Ongoing literature has proved this drug to be a safe and effective alternative pharmacotherapy.

Summary

Recent epidemiological data estimate up to one-third of the general adult population suffers from excessive daytime sleepiness. There is no cure to daytime somnolence and current pharmacotherapeutic regimens have worrisome side effect profiles. Solriamfetol is a new class of drug that offers a safe and effective alternative option for clinical providers treating excessive daytime sleepiness.

Carotid body hypersensitivity in intermittent hypoxia and obtructive sleep apnoea

Carotid bodies are the principal sensory organs for detecting changes in arterial blood oxygen concentration, and the carotid body chemoreflex is a major regulator of the sympathetic tone, blood pressure and breathing. Intermittent hypoxia is a hallmark manifestation of obstructive sleep apnoea (OSA), which is a widespread respiratory disorder. In the first part of this review, we discuss the role of carotid bodies in heightened sympathetic tone and hypertension in rodents treated with intermittent hypoxia, and the underlying cellular, molecular and epigenetic mechanisms. We also present evidence for hitherto-uncharacterized role of carotid body afferents in triggering cellular and molecular changes induced by intermittent hypoxia. In the second part of the review, we present evidence for a contribution of a hypersensitive carotid body to OSA and potential therapeutic intervention to mitigate OSA in a murine model.

Sleep-Disordered Breathing and Prevalent Hypertension in Men With and Without HIV

BACKGROUND

Sleep-disordered breathing (SDB) is a known risk factor for hypertension. Despite the well-established link between HIV infection and hypertension, it remains to be determined whether HIV infection modifies the association between SDB and hypertension.

SETTING

The Multicenter AIDS Cohort Study.

METHODS

SDB was assessed using in-home polysomnography in 779 men (436 with and 343 without HIV). The apnea-hypopnea index (AHI) based on oxyhemoglobin desaturation threshold of ≥3% or arousal (AHI 3a ) and ≥4% (AHI 4 ) along with oxygen desaturation index (ODI) were used to quantify SDB severity. Hypertension was defined as a blood pressure ≥140/90 mm Hg, use of antihypertensive medication, or self-report of a clinical diagnosis. The associations between HIV, SDB, and hypertension were characterized using multivariable logistic regression.

RESULTS

The prevalence of hypertension and SDB (AHI 3a ≥ 5 events/hr) was high, with estimates of 53.8% and 82.8%, respectively. Among men without SDB, HIV was independently associated with hypertension, with an adjusted odds ratio (OR) of 3.05 [95% confidence interval (CI): 1.33 to 7.01]. In men without HIV, SDB was associated with hypertension (OR: 2.93; 95% CI: 1.46 to 5.86). No significant increase in the odds of hypertension was noted in men with both HIV and SDB compared with men with either factor alone, with an OR of 3.24 (95% CI: 1.62 to 6.47). These results were consistent across different measures used to define SDB (AHI 3a , AHI 4 , ODI 3 , and ODI 4 ).

CONCLUSIONS

Predictors of hypertension differed by HIV status. SDB was associated with hypertension in men without HIV, but not in men with HIV. Among men with HIV, SDB did not affect the odds of hypertension.

Correlation between obstructive sleep apnea and ventricular function: a cross-sectional hospital-based study

BACKGROUND

Obstructive sleep apnoea (OSA) is a major cause of cardiovascular morbidity and mortality worldwide. Previous studies showed high prevalence of OSA in heart failure. We aimed to evaluate the association of OSA with cardiac dysfunction and the importance of myocardial performance index (Tei) in identifying cardiac dysfunction.

METHODS

Participants with OSA and sinus rhythm were included, while participants with arrhythmia, debilitating disease, or significant valvular heart disease were excluded. Thirty participants were enrolled, consecutively allocated in a single group, and underwent nocturnal polysomnography, electrocardiogram, and transthoracic echocardiography.

RESULTS

The prevalence of hypertension, diabetes, and smoking in the study population was 50%, 30%, and 23.3%, respectively. The mean body mass index and apnoea-hypopnoea index (AHI) of the study population was 40.11 ± 7.5 kg/m2 and22.12 ± 13.54 events/h, respectively. There were statistically significant differences between mild, moderate, and severe OSA regarding the left ventricular end diastolic diameter, left ventricular end systolic diameter, ejection fraction, and fractional shortening (p = 0.006, p = 0.002, p = 0.014 and p = 0.011),respectively. There were statistically significant regular positive correlations between the AHI and the right and left Tei (r = 0.447, p = 0.001 and r = 0.391, p = 0.003),respectively.

CONCLUSIONS

The prevalence of OSA was more in patients with comorbidities especially hypertension and diabetes. OSA was significantly associated with ventricular remodelling and cardiac dysfunction. A significant regular positive correlation was observed between the severity of OSA and worsening cardiac function as measured by Tei. Echocardiographic evaluation of the right and left ventricles and the right and left Tei could be considered as potentially valid, reproducible, and clinically applicable non-invasive methods for estimation of ventricular global function in patients with OSA.

Association between Obstructive Sleep Apnea and Intracranial Artery Calcification Stratified by Gender and Body Mass Index: A Hospital-Based Observational Study

BACKGROUND AND OBJECTIVES

Obstructive sleep apnea (OSA) is an independent risk factor for stroke. Furthermore, intracranial arterial calcification (IAC) has been validated as a marker for subclinical cerebrovascular disease. However, the relationship between OSA with IAC was less studied compared with its established association with coronary artery calcification. In this study, we aimed to investigate the association between the severity of OSA and the degree of IAC in hospitalized patients without preexisting cardiovascular disease.

METHODS

This hospital-based observational study was conducted from June 1, 2017, to May 1, 2019. In total, 901 consecutive patients who underwent head computed tomography scans and portable sleep monitoring were included. On the basis of the apnea-hypopnea index (AHI), patients were divided into four OSA severity groups (normal: AHI <5/h; mild: 5≤ AHI <15/h; moderate: 15≤ AHI <30/h; severe: AHI ≥30/h). Associations of OSA with IAC scores were assessed by using multivariate logistic regression analysis.

RESULTS

Of the 901 patients, 484 (53.7%) were men; the mean (SD) age was 66.1 (10.0) years. The non-OSA group included 207 (23.0%) patients; mild OSA, 209 (23.2%); moderate OSA, 235 (26.1%); and severe OSA, 169 (18.8%). Mean IAC scores were higher in the severe OSA group compared with non-, mild, and moderate OSA groups (4.79 vs. 2.58; 4.79 vs. 2.94; 4.79 vs. 3.39; p < 0.001). Multivariate analysis adjusted for confounding factors revealed that only severe OSA was associated with a higher IAC score (odds ratio [OR]: 1.65; 95% confidence interval [CI]: 1.43-1.91; p < 0.001). In stratified analyses by BMI, among participants with a BMI <25 kg/m2, the positive association between AHI values and IAC scores was found in the moderate OSA group (OR: 1.23; 95% CI: 1.05, 1.43; p = 0.01) and the severe OSA group (OR: 1.96; 95% CI: 1.55, 2.48; p < 0.001). When stratified by gender, in women, the positive association was found in the moderate OSA group (adjusted OR: 1.21; 95% CI: 1.02-1.51; p = 0.016) and the severe OSA group (adjusted OR: 1.76; 95% CI: 1.36-2.25; p < 0.001). For the men group, a positive association between IAC scores and AHI was only observed in the severe OSA group.

DISCUSSION

These findings suggest that OSA, in particular severe OSA (AHI ≥30), is independently associated with higher IAC scores. Women and no-obesity individuals appeared more susceptible to adverse OSA-related subclinical cerebrovascular disease as measured by IAC scores.

Investigating associations between social determinants, self-efficacy measurement of sleep apnea and CPAP adherence: the SEMSA study

Study objectives

The prospective Self-Efficacy Measure for Sleep Apnea study (SEMSAS) is investigating thresholds for health literacy, self-efficacy and precariousness at obstructive sleep apnea (OSA) diagnosis to predict CPAP adherence. This paper describes the study protocol and presents baseline data from the ongoing study.

Methods

Eligible individuals had confirmed OSA and were referred to a homecare provider for continuous positive airway pressure (CPAP) therapy initiation. Data on patient characteristics and comorbidities were collected, along with baseline evaluations of self-efficacy [15-item Self-Efficacy Measure for Sleep Apnea tool (SEMSA-15)], precariousness [Deprivation in Primary Care Questionnaire (DipCareQ)], and health literacy (Health Literacy Questionnaire). CPAP adherence over 12 months of follow-up will be determined using remote monitoring of CPAP device data. The primary objective is to define an optimal SEMSA-15 score threshold to predict CPAP adherence at 3- and 12-month follow-up.

Results

Enrollment of 302 participants (71% male, median age 55 years, median body mass index 31.6 kg/m²) is complete. Low self-efficacy (SEMSA-15 score ≤ 2.78) was found in 93/302 participants (31%), and 38 (12.6%) reported precariousness (DipCareQ score > 1); precariousness did not differ significantly between individuals with a SEMSA-15 score ≤ 2.78 versus >2.78. Health literacy was generally good, but was significantly lower in individuals with versus without precariousness, and with low versus high self-efficacy.

Conclusion

SEMSAS is the first study using multidimensional baseline assessment of self-efficacy, health literacy and precariousness, plus other characteristics, to determine future adherence to CPAP, including CPAP adherence trajectories. Collection of follow-up data is underway.

Description of a novel method for detection of sleep-disordered breathing in brachycephalic dogs

BACKGROUND

Sleep-disordered breathing (SDB), defined as any difficulty in breathing during sleep, occurs in brachycephalic dogs. Diagnostic methods for SDB in dogs require extensive equipment and laboratory assessment.

OBJECTIVES

To evaluate the usability of a portable neckband system for detection of SDB in dogs. We hypothesized that the neckband is a feasible method for evaluation of SDB and that brachycephaly predisposes to SDB.

ANIMALS

Twenty-four prospectively recruited client-owned dogs: 12 brachycephalic dogs and 12 control dogs of mesocephalic or dolicocephalic breeds.

METHODS

Prospective observational cross-sectional study with convenience sampling. Recording was done over 1 night at each dog's home. The primary outcome measure was the obstructive Respiratory Event Index (OREI), which summarized the rate of obstructive SDB events per hour. Additionally, usability, duration of recording, and snore percentage were documented.

RESULTS

Brachycephalic dogs had a significantly higher OREI value (Hodges-Lehmann estimator for median difference = 3.5, 95% confidence interval [CI] 2.2-6.8; P < .001) and snore percentage (Hodges-Lehmann estimator = 34.2, 95% CI 13.6-60.8; P < .001) than controls. A strong positive correlation between OREI and snore percentage was detected in all dogs (rs = .79, P < .001). The neckband system was easy to use.

CONCLUSIONS AND CLINICAL IMPORTANCE

Brachycephaly is associated with SDB. The neckband system is a feasible way of characterizing SDB in dogs.

Association between obstructive sleep apnea and resistant hypertension: systematic review and meta-analysis

Introduction

Obstructive sleep apnea syndrome (OSAS) is a chronic disorder characterized by recurring episode obstruction and collapse of upper airways during sleep, leading to hypoxia and sleep disruption. OSAS is commonly associated with an increased prevalence of hypertension. The underlying mechanism in OSA with hypertension is related to intermittent hypoxia. This hypoxia induces endothelial dysfunction, overactivity of sympathetic effects, oxidative stress, and systemic inflammation. Hypoxemia triggers the sympathetic process's overactivity, leading to the development of resistant hypertension in OSA. Thus, we hypothesize to evaluate the association between resistant hypertension and OSA.

Methods

The PubMed, ClinicalTrails.gov, CINAHL, Google Scholar, Cochrane Library, and Science Direct databases were searched from 2000 to January 2022 for studies demonstrating the association between resistant hypertension and OSA. The eligible articles underwent quality appraisal, meta-analysis, and heterogeneity assessment.

Results

This study comprises seven studies, including 2,541 patients ranged from 20 to 70 years. The pooled analysis of six studies demonstrated that OSAS patients with a history of increased age, gender, obesity, and smoking status are at an increased risk for resistant hypertension (OR: 4.16 [3.07, 5.64], I²:0%) than the non-OSAS patients. Similarly, the pooled effect demonstrated that patients with OSAS were at an increased risk of resistant hypertension (OR: 3.34 [2.44, 4.58]; I²:0%) than the non-OSAS patients when all associated risk factors were adjusted using multivariate analysis.

Conclusion

This study concludes that OSAS patients with or without related risk factors demonstrated increased risk for resistant hypertension.

Investigating the Relationship between Obstructive Sleep Apnoea, Inflammation and Cardio-Metabolic Diseases

Obstructive sleep apnoea (OSA) is a prevalent underdiagnosed disorder whose incidence increases with age and weight. Uniquely characterised by frequent breathing interruptions during sleep-known as intermittent hypoxia (IH)-OSA disrupts the circadian rhythm. Patients with OSA have repeated episodes of hypoxia and reoxygenation, leading to systemic consequences. OSA consequences range from apparent symptoms like excessive daytime sleepiness, neurocognitive deterioration and decreased quality of life to pathological complications characterised by elevated biomarkers linked to endocrine-metabolic and cardiovascular changes. OSA is a well-recognized risk factor for cardiovascular and cerebrovascular diseases. Furthermore, OSA is linked to other conditions that worsen cardiovascular outcomes, such as obesity. The relationship between OSA and obesity is complex and reciprocal, involving interaction between biological and lifestyle factors. The pathogenesis of both OSA and obesity involve oxidative stress, inflammation and metabolic dysregulation. The current medical practice uses continuous positive airway pressure (CPAP) as the gold standard tool to manage OSA. It has been shown to improve symptoms and cardiac function, reduce cardiovascular risk and normalise biomarkers. Nonetheless, a full understanding of the factors involved in the deleterious effects of OSA and the best methods to eliminate their occurrence are still poorly understood. In this review, we present the factors and evidence linking OSA to increased risk of cardiovascular conditions.

Is the Gut Microbiome Implicated in the Excess Risk of Hypertension Associated with Obstructive Sleep Apnea? A Contemporary Review

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder and an established risk factor for cardiovascular diseases, including hypertension. The pathogenesis of elevated blood pressure (BP) in OSA is multifactorial, including sympathetic overdrive, vascular aberrations, oxidative stress, inflammation, and metabolic dysregulation. Among the mechanisms potentially involved in OSA-induced hypertension, the role of the gut microbiome is gaining increasing attention. Perturbations in the diversity, composition, and function of the gut microbiota have been causally linked to numerous disorders, and robust evidence has identified gut dysbiosis as a determinant of BP elevation in various populations. In this brief review, we summarize the current body of literature on the implications of altered gut microbiota for hypertension risk in OSA. Data from both preclinical models of OSA and patient populations are presented, and potential mechanistic pathways are highlighted, along with therapeutic considerations. Available evidence suggests that gut dysbiosis may promote the development of hypertension in OSA and may thus be a target for interventions aimed at attenuating the adverse consequences of OSA in relation to cardiovascular risk.

Discovery of genomic loci associated with sleep apnea risk through multi-trait GWAS analysis with snoring

STUDY OBJECTIVES

Despite its association with severe health conditions, the etiology of sleep apnea (SA) remains understudied. This study sought to identify genetic variants robustly associated with SA risk.

METHODS

We performed a genome-wide association study (GWAS) meta-analysis of SA across five cohorts (NTotal = 523 366), followed by a multi-trait analysis of GWAS (multi-trait analysis of genome-wide association summary statistics [MTAG]) to boost power, leveraging the high genetic correlation between SA and snoring. We then adjusted our results for the genetic effects of body mass index (BMI) using multi-trait-based conditional and joint analysis (mtCOJO) and sought replication of lead hits in a large cohort of participants from 23andMe, Inc (NTotal = 1 477 352; Ncases = 175 522). We also explored genetic correlations with other complex traits and performed a phenome-wide screen for causally associated phenotypes using the latent causal variable method.

RESULTS

Our SA meta-analysis identified five independent variants with evidence of association beyond genome-wide significance. After adjustment for BMI, only one genome-wide significant variant was identified. MTAG analyses uncovered 49 significant independent loci associated with SA risk. Twenty-nine variants were replicated in the 23andMe GWAS adjusting for BMI. We observed genetic correlations with several complex traits, including multisite chronic pain, diabetes, eye disorders, high blood pressure, osteoarthritis, chronic obstructive pulmonary disease, and BMI-associated conditions.

CONCLUSION

Our study uncovered multiple genetic loci associated with SA risk, thus increasing our understanding of the etiology of this condition and its relationship with other complex traits.

Respiratory effort during sleep and prevalent hypertension in obstructive sleep apnoea

BACKGROUND

Mechanisms underlying blood pressure changes in obstructive sleep apnoea (OSA) are incompletely understood. Increased respiratory effort is one of the main features of OSA and is associated with sympathetic overactivity, leading to increased vascular wall stiffness and remodelling. This study investigated associations between a new measure of respiratory effort (percentage of total sleep time spent with increased respiratory effort based on measurement of mandibular jaw movements (MJM): REMOV, %TST) and prevalent hypertension in adults referred for evaluation of suspected OSA.

METHODS

A machine learning model was built to predict hypertension from clinical data, conventional polysomnography (PSG) indices and MJM-derived parameters (including REMOV). The model was evaluated in a training subset and a test subset.

RESULTS

The analysis included 1127 patients: 901 (80%) in the training subset and 226 (20%) in the test subset. The prevalence of hypertension was 31% and 30%, respectively, in the training and test subsets. A risk stratification model based on 18 input features including REMOV had good accuracy for predicting prevalent hypertension (sensitivity 0.75 and specificity 0.83). Using the Shapley additive explanation method, REMOV was the best predictor of hypertension after clinical risk factors (age, sex, body mass index and neck circumference) and time with oxygen saturation <90%, ahead of standard PSG metrics (including the apnoea-hypopnoea index and oxygen desaturation index).

CONCLUSION

The proportion of sleep time spent with increased respiratory effort automatically derived from MJM was identified as a potential new reliable metric to predict prevalent hypertension in patients with OSA.

[Sleep-Disordered Breathing at High Altitude: Its Characteristics and Research Progress in Treatment]

Hypobaric hypoxia in regions of high altitude may increase the risk of having sleep-disordered breathing (SDB). SDB at high altitude mainly refers to the SDB incurred in highlanders and lowlanders at a high altitude. At present, research on SDB at high altitude is mainly focused on these two groups of people. On the one hand, highlanders have SDB at a higher prevalence and greater severity than lowlanders do and highlanders have a prolonged duration of apnea when they travel to low-altitude regions. On the other hand, the severity of SDB increased in lowlanders when they travel to high altitude, represented mainly by an increase in central and hypopnea events. In terms of treatment, a substantial number of studies have shown that medication, including acetazolamide and dexamethasone, and nocturnal oxygen supplementation could improve SDB in lowlanders when they travel to high altitude. However, not much research has been done on the treatment of SDB in highlanders and it has only been reported that nocturnal oxygen supplementation was an available treatment option. Herein, we summarized the latest research findings on SDB at high altitude, providing the basis for further studies about the characteristics and treatments for highlanders with SDB.

Obstructive Sleep Apnea and Obesity Are Associated with Hypertension in a Particular Pattern: A Retrospective Study

Obstructive sleep apnea (OSA) and obesity can increase the risk of hypertension, but the combined effects of these two conditions on hypertension are not yet known. We collected the basic characteristics, sleep parameters, and glucose levels of subjects with a polysomnography test and divided them into four groups, according to whether they had severe OSA and obesity or not. The main effects of severe OSA and obesity and the interactions of the two on systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels were detected using analysis of covariance. The association between obesity and severe OSA and abnormal blood pressure and their combined effects were detected with logistic regression. In total, 686 subjects were included. After adjusting for multiple confounding factors, the strong main effects of obesity and severe OSA were detected in the SBP and DBP levels, with no combined effects from the two conditions on SBP or DBP. Obesity was independently associated with the presence of hyper-systolic blood pressure (hyper-SBP) and hypertension, and severe OSA was independently associated with the presence of hyper diastolic blood pressure (hyper-DBP) and hypertension. No effects of the interaction between severe OSA and obesity on the presence of abnormal blood pressure were observed. Both severe OSA and obesity were associated with hypertension, while obesity was closely associated with hyper-SBP, and severe OSA was associated with hyper-DBP. No effects of the interaction between these two on hypertension were observed.

Age-dependent cardiorespiratory directional coupling in wake-resting state

Objective.Cooperation in the cardiorespiratory system helps maintain internal stability. Various types of system interactions have been investigated; however, the characteristics of the interactions have mostly been studied using data collected in well-defined physiological states, such as sleep. Furthermore, most analyses provided general information about the interaction, making it difficult to quantify how the systems influenced one another.Approach.Cardiorespiratory directional coupling was investigated in different age groups (20 young and 19 elderly subjects) in a wake-resting state. The directionality index (DI) was calculated using instantaneous phases from the heartbeat interval and respiratory signal to provide information about the strength and direction of interaction between the systems. Statistical analysis was performed between the groups on the DI and independent measures of directionality (nc_r: influence from cardiac system to respiratory system, and nc_c: influence from the respiratory system to the cardiac system).Main results.The values of DI were -0.52 and -0.17 in the young and elderly groups, respectively (p< 0.001). Furthermore, the values of nc_rand nc_cwere found to be significantly different between the groups (p< 0.001), respectively.Significance.Changes in both directions between the systems influence different aspects of cardiorespiratory coupling between the groups. This observation could be linked to different levels of autonomic modulation associated with ageing. Our approach could aid in quantitatively tracking and comprehending how systems interact in response to physiological and environmental changes. It could also be used to understand how abnormal interaction characteristics influence physiological system dysfunctions and disorders.

Study on Relationship Between Carotid Intima-Media Thickness and Inflammatory Factors in Obstructive Sleep Apnea

Purpose

The purpose of this study was to explore the change of carotid intima-media thickness (IMT) and its correlation with inflammatory markers in patients with different degrees of obstructive sleep apnea (OSA).

Methods

One hundred hospitalized patients were selected and were divided into the normal control group (21 cases), the mild-moderate group (39 cases) and the severe group (40 cases) according to their apnea hypopnea index (AHI). Carotid IMT of all registered patients was studied with ultrasound, and serum levels of high-sensitivity C-reactive protein (hs-CRP), Lipoprotein-associated phospholipaseA2 (Lp-PLA2) and tumor necrosis factor-α (TNF-α) were measured. Pearson correlation analysis and multiple stepwise regression analysis were used to analyze the correlation between carotid IMT and inflammatory factors.

Results

Patients with mild, moderate and severe OSA Carotid IMT had significantly higher levels of serum hs-CRP, Lp-PLA2 and TNF-α compared with the normal control group (P < 0.001). The levels of carotid IMT, serum protein hs-CRP, Lp-PLA2 and TNF-α in the severe OSA group were significantly higher than those of the mild-moderate OSA group, with P values being less than 0.001. Carotid artery IMT was positively correlated with serum hs-CRP (r = 0.83, P < 0.001), Lp-PLA2 (r =0.58, P < 0.001), and TNF-α (r =0.69, P < 0.001). hs-CRP, TNF-α and AHI were independent factors affecting carotid artery IMT. In addition, AHI was an independent indicator of carotid atherosclerosis (P = 0.0012).

Conclusion

Increased inflammatory factors in OSA patients might cause the progression of atherosclerosis, which might increase the risk of cardiovascular and cerebrovascular diseases in OSA patients.

Associations between common sleep disturbances and cardiovascular risk in patients with obstructive sleep apnea: A large-scale cross-sectional study

Objectives

Studies have shown that obstructive sleep apnea (OSA) is inextricably linked with cardiovascular diseases (CVD). However, the roles of certain common sleep disturbances, such as low slow-wave sleep, excessive daytime sleepiness and short sleep duration, in the pathogenesis and progression of CVD in patients with OSA have not been determined. Therefore, we conducted a large cross-sectional study to explore the effect of low slow-wave sleep, excessive daytime sleepiness and short sleep duration on the risk of CVD in patients with OSA.

Methods

Subjects were consecutively enrolled to participate in the sleep center of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital. All OSA patients were diagnosed by standard polysomnography, while controls were all simple snorers. A total of 4,475 participants were strictly recruited. The Framingham Risk Score were employed to assess the 10-year risk of CVD, and logistic regression was used to measure the association between sleep disturbances and the moderate-to-high CVD risk.

Results

In the whole cohort, OSA, excessive daytime sleepiness, and low slow-wave sleep were all risk factors for the moderate-to-high 10-year CVD risk (odds ratio [OR] = 3.012, 95% confidence interval [CI] 2.418–3.751; OR = 1.407, 95% CI: 1.228–1.613, and OR = 0.973,95% CI: 0.967–0.980), but sleep duration did not contribute significantly to that risk. Whether in patients with OSA and controls, low SWS (<12.8%) could increase the risk of CVD. Subjective excessive daytime sleepiness would significantly increase the risk of CVD only in patients with severe OSA.

Conclusion

It is important to pay more attention to the impact of sleep on cardiovascular health. Patients with sleep disturbances should adopt a healthy lifestyle and undergo regular follow-up of cardiovascular indicators to prevent cardiovascular complications.

Trial registration

[http://www.chictr.org.cn/showproj.aspx?proj=43057], identifier [ChiCTr1900025714].

Modified Uvulopalatopharyngoplasty with Tonsillectomy in Treatment of Obstructive Sleep Apnoea

Obstructive sleep apnoea is a common problem with many long-term consequences if left untreated. The purpose of this study is to find the efficacy of modified uvulopalatopharyngoplasty with tonsillectomy in the treatment of OSA symptoms, apnoea-hypopnoea index, Epworth sleepiness scale and its effect on blood pressure and cardiac status. Patients with obstructive sleep apnoea with apnoea-hypopnoea index more than 15 with tonsillar hypertrophy, Friedman stage < 3 and palatal collapse or obstruction at the level of velum as diagnosed by DISE were included in this prospective analytical cross-sectional study. Modified uvulopalatopharyngoplasty with tonsillectomy was done in all patients. History of nocturnal and daytime OSA symptoms, Epworth sleepiness scale, snoring score, polysomnogram, drug induced sleep endoscopy, blood pressure, echocardiogram to measure velocity across pulmonary and aortic valve and ECG were taken preoperatively and 6 months postoperatively. A total of 129 participants were recruited. 82 of the 129 patients (63.5%) were men; mean (SD) age was 44.2 (6.78) years. The patients were post operatively classified as responders and non-responders by the DISE finding. 107 patients (82.9%)-responders, had no narrowing and 22 patients (17.1%)-non-responders, had persistent narrowing of velum. Non-responders had increased baseline BMI when compared to responders. All the parameters were statistically improved in responders (p < 0.001). In non-responders, there was no statistical improvement in any of the parameters. Modified uvulopalatopharyngoplasty provides significant improvement in sleep parameters like AHI, Epworth sleepiness scale and other polysomnographic parameters. It significantly reduces the cardiac burden in OSA patients without any complications. Trial registration www.ctri.nic.in identifier: CTRI/2020/06/025759.

Intermittent Hypoxia and Atherosclerosis: From Molecular Mechanisms to the Therapeutic Treatment

Intermittent hypoxia (IH) has a dual nature. On the one hand, chronic IH (CIH) is an important pathologic feature of obstructive sleep apnea (OSA) syndrome (OSAS), and many studies have confirmed that OSA-related CIH (OSA-CIH) has atherogenic effects involving complex and interacting mechanisms. Limited preventive and treatment methods are currently available for this condition. On the other hand, non-OSA-related IH has beneficial or detrimental effects on the body, depending on the degree, duration, and cyclic cycle of hypoxia. It includes two main states: intermittent hypoxia in a simulated plateau environment and intermittent hypoxia in a normobaric environment. In this paper, we compare the two types of IH and summarizes the pathologic mechanisms and research advances in the treatment of OSA-CIH-induced atherosclerosis (AS), to provide evidence for the systematic prevention and treatment of OSAS-related AS.

The multisystemic effects of oral appliance therapy for obstructive sleep apnea: A narrative review

Obstructive sleep apnea (OSA) is a chronic condition accompanied by repeated obstruction of the upper airway during sleep despite respiratory efforts, resulting in intermittent hypoxemia, altered sleep structure, and sympathetic activation. Previous studies have shown a significant association between OSA and general health issues such as cardiovascular diseases, endocrine disorders, neurocognitive function decline, and poor quality of life. Continuous positive airway pressure (CPAP) has been considered as the first line treatment for OSA. However, accumulating evidence supports the role of oral appliance (OA) therapy, including mandibular advancement devices, as an alternative option for snoring and OSA patients who do not comply with or refuse CPAP usage. Despite a generally favorable outcome of OA therapy for OSA related respiratory indices, studies focusing on the impact of systemic effects of OA therapy in OSA patients are relatively scarce compared with the extensive literature focusing on the systemic effects of CPAP. Therefore, this article aimed to provide an overview of the current evidence regarding the multisystemic effects of OA therapy for OSA.

Assessment of hypertension in obstructive sleep apnea by ambulatory blood pressure monitoring: a systematic review and meta-analysis

Among obstructive sleep apnea (OSA) patients, there exists a high prevalence of hypertension. Determining the optimal blood pressure (BP) monitoring modality in this population will lead to a better understanding of hypertension profiles and a more accurate diagnosis of hypertension. PubMed, Ovid/Medline, Web of Science, Scopus, Cochrane Library, and CINAHL databases were screened, and the relevant articles regarding BP monitoring in OSA patient population were selected. Studies evaluating both ambulatory (ABPM) and office BP measurements were selected to be analyzed for the hypertension diagnosis specificity of ABPM measurement in OSA patients compared with office measurements. If reported, additional information regarding white-coat, masked hypertension, and circadian BP pattern prevalence was included. A cumulative analysis of five studies revealed a prevalence of hypertension based on BP to be 44%, whereas a cumulative analysis of four studies revealed a prevalence of hypertension based on ABPM to be 66%. Excluding a study with the nighttime assessment of hypertension reduced the cumulative prevalence of hypertension in OSA patients to 59%. The cumulative prevalence of Studies demonstrated the prevalence of masked and white-coat hypertension to be 34 and 9%, respectively. As a higher prevalence of hypertension was detected by ABPM and nighttime measurement, it can be deduced that ABPM is more sensitive in determining OSA patients with hypertension, and that nighttime ABPM further increases this sensitivity. The presence of masked and white-coat hypertension in OSA patients underlines the importance of correct hypertension diagnosis as it affects further management in this population with increased cardiovascular risk.

Obstruktive Schlafapnoe und arterielle Hypertonie

Hintergrund

In Deutschland leiden rund 19 Mio. Patienten an einer diagnostizierten arteriellen Hypertonie (aHT). Die Schnittmenge zwischen Menschen mit aHT und obstruktiver Schlafapnoe (OSA) ist groß. Aufwachreaktionen und Hypoxämie im Rahmen einer OSA können zu einem gesteigerten Sympathikotonus und endothelialer Dysfunktion und somit zu aHT führen.

Fragestellung

Der vorliegende Übersichtsartikel soll die Zusammenhänge zwischen OSA und aHT sowie Behandlungsmöglichkeiten darstellen.

Materialien und Methoden

Es erfolgte eine Literaturrecherche von Original- und Übersichtsartikeln, die bis 2021 in der PubMed-Datenbank veröffentlicht wurden.

Ergebnisse

Obstruktive Schlafapnoe kann sowohl die Entstehung als auch die Verschlechterung einer aHT verursachen. Betroffene profitieren von einer CPAP-Behandlung mit einer durchschnittlichen Senkung des systolischen Blutdrucks um −4,4 mm Hg sowie des diastolischen Blutdrucks um −2,9 mm Hg. Prädiktoren für eine Reduktion des Blutdrucks unter kontinuierlicher Positivdrucktherapie (CPAP) sind junges Alter, therapieresistente aHT, schwere OSA-bedingte Sauerstoffentsättigungen und ein „Non-Dipping-Blutdruckmuster“.

Schlussfolgerung

Die adäquate Behandlung einer aHT fordert häufig einen multimodalen Ansatz. Neben einer medikamentösen antihypertensiven Therapie und einer Modifikation des Lebensstils sollte auch die Diagnose und gegebenenfalls die Behandlung einer OSA berücksichtigt werden.

Relationships Between Cardinal Features of Obstructive Sleep Apnea and Blood Pressure: A Retrospective Study

BACKGROUND

Obstructive sleep apnea (OSA) is associated with hypertension; however, the associations between cardinal features of OSA, such as intermittent hypoxia (IH) and sleep fragmentation (SF), and blood pressure remain unclear. We performed this study to address this issue.

METHOD

We investigated 335 subjects with the polysomnography (PSG) tests. Data, including basic characteristics, PSG parameters, and blood pressure, were collected. We calculated p-values for linear trends of blood pressure across oxygen-desaturation index (ODI)/microarousal index (MAI) quartiles. Logistic regressions were used to determine the risk factors for abnormal blood pressure and to detect the multiplicative interaction between ODI and MAI with blood pressure.

RESULTS

After adjusting for multiple variables, compared with subjects with lower ODI quartiles, those with higher ODI quartiles had significant higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) (p for trend = 0.010 and 0.018, respectively). And compared with subjects with lower ODI quartiles, those with higher ODI quartiles were also more likely to have abnormal DBP and hypertension after adjusting for multiple variables. Similarly, compared with subjects with lower MAI quartiles, those with higher MAI quartiles had significant higher SBP and DBP, and were more likely to have abnormal DBP and hypertension. No significant multiplicative interactions between ODI and MAI with blood pressure were detected.

CONCLUSION

Subjects with more severe IH/SF had significant higher blood pressure and were more likely to have abnormal DBP and hypertension than those with less severe IH/SF. No interaction between IH and SF on the relationship with blood pressure was shown.

Interaction between trouble sleeping and depression on hypertension in the NHANES 2005-2018

BACKGROUND

Hypertension, trouble sleeping and depression, as three major public health problems, were closely related. This study evaluated the independent association of trouble sleeping and depression with hypertension and interaction effect between trouble sleeping and depression on hypertension in Americans.

METHOD

The data of this cross-sectional study was from the 2005-2018 National Health and Nutritional Examination Survey (NHANES) with hypertension, depression, trouble sleeping and confounding factor information. Multivariate logistic regression model and subgroup analyses of depression severity were conducted to assess the relationship between trouble sleeping and depression on hypertension. Relative excess risk due to interaction (RERI), attributable proportion of interaction (AP) and synergy index (S) were utilized to assess the additive interaction.

RESULTS

A total of 30,434 participants (weighted n = 185,309,883) were examined with 16,304 (49.37%) known hypertensive subjects. Compared with participants without trouble sleeping, those with trouble sleeping had a higher risk of hypertension [OR = 1.359 (95% CI: 1.229-1.503)]. We also found the significant association of depression with an increased risk of hypertension [OR = 1.276 (95% CI: 1.114-1.462)], compared with those without depression. Moreover, there was a significant interaction between trouble sleeping and depression on hypertension risk [RERI = 0.528 (95% CI: 0.182-0.873), AP = 0.302 (95% CI: 0.140-0.465), S = 3.413 (95% CI: 1.301-8.951)].

CONCLUSION

There was a synergistic interaction between trouble sleeping and depression on hypertension, especially the significant synergistic effect between moderate depression and trouble sleeping on hypertension. The results suggested that improving the psychological status and trouble sleeping of patients may be beneficial to the prevention and treatment of hypertension.

Effect of acetazolamide on obstructive sleep apnoea in highlanders: protocol for a randomised, placebo-controlled, double-blinded crossover trial

INTRODUCTION

Obstructive sleep apnoea (OSA) is a highly prevalent disease that causing systemic hypertension. Furthermore, altitude-dependent hypobaric hypoxic condition and Tibetan ethnicity have been associated with systemic hypertension independent of OSA, therefore patients with OSA living at high altitude might be at profound risk to develop systemic hypertension. Acetazolamide has been shown to decrease blood pressure, improve arterial oxygenation and prevent high altitude periodic breathing in healthy volunteers ascending to high altitude and decrease blood pressure in patients with systemic hypertension at low altitude. However, the effect of acetazolamide on 24-hour blood pressure, sleep-disordered disturbance and daytime cognitive performance in patients with OSA permanently living at high altitude has not been studied.

METHODS AND ANALYSIS

This study protocol describes a randomised, placebo-controlled, double-blinded crossover trial. Highland residents of both sexes, aged 30-60 years, Tibetan ethnicity, living at an elevation of 3650 m and apnoea-hypopnoea index over 15/hour will be included. Participants will be randomly assigned to a 2×2 week treatment period starting with 750 mg/day acetazolamide followed by placebo treatment or vice versa, separated by a 1-week wash-out phase. Clinical assessments, 24-hour ambulatory blood pressure monitoring (ABPM), polysomnography (PSG), near-infrared spectroscopy, nocturnal fluid shift and cognitive performance will be assessed before and at the end of each treatment period. The primary outcome will be the difference in 24-hour mean blood pressure between acetazolamide therapy and placebo; secondary outcomes will be the difference in other 24-hour ABPM-derived parameters, PSG-derived parameters, cognitive performance and overnight change in different segments of fluid volume between acetazolamide therapy and placebo. Accounting for potential dropouts, 40 participants will be recruited.

ETHICS AND DISSEMINATION

The protocol was approved by the West China Hospital of Sichuan University Biomedical Research Ethics Committee. Recruitment will start in spring 2022. Dissemination of the results include presentations at conferences and publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR2100049304.

Evaluation and Management of Secondary Hypertension

Hypertension is a major cause of cardiovascular morbidity and mortality globally. Many patients with hypertension have secondary causes of hypertension that merit further evaluation. For example, secondary hypertension can result in target organ damage to the heart, kidneys, and brain independent of the effects of blood pressure. Several causes benefit from targeted therapies to supplement first-line antihypertensive agents. However, secondary hypertension is often underrecognized. The goal of this review is to highlight optimal approaches to the diagnosis and management of common causes of secondary hypertension, including primary aldosteronism, renovascular hypertension, obstructive sleep apnea, and drug-induced hypertension.

The 3% Oxygen Desaturation Index is an Independent Risk Factor for Hypertension Among Children with Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) and obesity are both directional risk factors of hypertension. Chronic intermittent hypoxemia (IH) is a commonly observed pathophysiological mechanism involved in multiple comorbidities of OSA. However, their interactions are not well understood in children. This study aimed to investigate the associations of IH indexes (oxygen desaturation index 3% [ODI3], mean peripheral oxygen saturation [SpO₂], least SpO₂, and time with SpO₂ < 85%), apnea-hypopnea index, and weight status with hypertension in a sample of pediatric OSA patients.

METHODS

The medical records of 365 pediatric OSA patients were retrospectively reviewed in this cross-sectional study. Demographics, anthropometrics, standard in-laboratory polysomnography, and nocturnal blood pressure were collected. Multivariate logistic regression with forward selection was used to identify independent predictors of hypertension.

RESULTS

Multivariate logistic regression analysis showed that ODI3 (odds ratio [OR] = 1.02, 95% confidence interval [CI] = 1.01-1.03) and body mass index z-score (OR = 1.34, 95% CI = 1.12-1.60) were independent continuous predictors of pediatric hypertension, whilst severe OSA (OR = 2.62, 95% CI = 1.60-4.29) and overweight/obesity (OR = 2.63, 95% CI = 1.59-4.34) were independent categorical predictors. Traditional risk factors including male sex (OR = 2.33, 95% CI = 1.02-5.33), late childhood/adolescence (OR = 1.98, 95% CI = 1.01-3.88), and overweight/obesity (OR = 2.97, 95% CI = 1.56-5.67) combined with sleep hypoxemia (least SpO₂ ≤ 95%) (OR = 2.24, 95% CI = 1.16-4.04) predicted hypertension (R ² = 0.21) in the severe IH subgroup (n = 205), while the no/mild IH subgroup (n = 160) had an entirely different predictor, severe OSA (OR = 3.81, 95% CI = 1.49-9.74) (R ² = 0.07).

CONCLUSION

The close relationships among IH, overweight/obesity, and hypertension highlight the importance of reducing IH and body weight in children with OSA.