Efficacy of continuous positive airway pressure (CPAP) in the prevention of cardiovascular events in patients with obstructive sleep apnea: Systematic review and meta-analysis

Heterogeneous Effects of Continuous Positive Airway Pressure in Non-Sleepy Obstructive Sleep Apnea on Cardiovascular Disease Outcomes: Post Hoc Machine Learning Analysis of the ISAACC Trial (ECSACT Study)

Rationale: Randomized controlled trials of continuous positive airway pressure (CPAP) therapy for cardiovascular disease (CVD) prevention among patients with obstructive sleep apnea (OSA) have been largely neutral. However, given that OSA is a heterogeneous disease, there may be unidentified subgroups demonstrating differential treatment effects. Objectives: We sought to apply a novel data-drive approach to identify nonsleepy OSA subgroups with heterogeneous effects of CPAP on CVD outcomes within the Impact of Sleep Apnea Syndrome in the Evolution of Acute Coronary Syndrome (ISAACC) study. Methods: Participants were randomly partitioned into two datasets. One for training (70%) our machine-learning model and a second (30%) for validation of significant findings. Model-based recursive partitioning was applied to identify subgroups with heterogeneous treatment effects. Survival analysis was conducted to compare treatment (CPAP vs. usual care [UC]) outcomes within subgroups. Results: A total of 1,224 nonsleepy OSA participants were included. Of 55 features entered into our model, only two appeared in the final model (i.e., average OSA event duration and hypercholesterolemia). Among participants at or below the model-derived average event duration threshold (19.5 s), CPAP was protective for a composite of CVD events (training hazard ratio [HR], 0.46; P = 0.002). For those with longer event duration (>19.5 s), an additional split occurred by hypercholesterolemia status. Among participants with longer event duration and hypercholesterolemia, CPAP resulted in more CVD events compared with UC (training HR, 2.24; P = 0.011). The point estimate for this harmful signal was also replicated in the testing dataset (HR, 1.83; P = 0.118). Conclusions: We discovered subgroups of nonsleepy OSA participants within the ISAACC study with heterogeneous effects of CPAP. Among the training dataset, those with longer OSA event duration and hypercholesterolemia had nearly 2.5 times more CVD events with CPAP compared with UC, whereas those with shorter OSA event duration had roughly half the rate of CVD events if randomized to CPAP.

Sleep apnea and ischemic stroke- a perspective for translational preclinical modelling

Obstructive sleep apnea (OSA) is associated with ischemic stroke. There is, however, a lack of knowledge on the exact cause-effect relationship, and preclinical models of OSA for experimental ischemic stroke investigations are not well characterized. In this review, we discuss sleep apnea and its relationship with stroke risk factors. We consider how OSA may lead to ischemic stroke and how OSA-induced metabolic syndrome and hypothalamic-pituitary axis (HPA) dysfunction could serve as therapeutic targets to prevent ischemic stroke. Further, we examine the translational potential of established preclinical models of OSA. We conclude that metabolic syndrome and HPA dysfunction, which are often overlooked in the context of experimental stroke and OSA studies, are crucial for experimental consideration to improve the body of knowledge as well as the translational potential of investigative efforts.

Effect of CPAP Treatment on Cardiovascular Outcomes

INTRODUCTION

Randomized controlled trials (RCT) have not demonstrated a role for continuous positive airway pressure (CPAP) on the secondary prevention of major cardiovascular events in obstructive sleep apnea (OSA) patients. However, participants in RCTs are substantially different from real-world patients. Therefore, we aimed to assess the effect of CPAP treatment on major cardiovascular events in real-world OSA patients.

METHODS

Population-based longitudinal observational study including all OSA patients with an active CPAP prescription at the beginning of 2011 in Catalonia, Spain, that terminated CPAP treatment during 2011 and did not have CPAP prescriptions between 2012-2015; and propensity-score-matched OSA patients that continued CPAP treatment until the end of 2015 or death. Adjusted hazard ratios were used to assess the association between CPAP treatment and overall and cardiovascular mortality, cardiovascular hospitalizations, or major adverse cardiovascular events (MACEs).

RESULTS

3638 CPAP terminators and 10,914 propensity-score-matched continuators were included (median age 67 [57-77] years, 71.4% male). During a median follow-up of 47.9 months CPAP continuators showed a lower risk of cardiovascular death than terminators (hazard ratio [HR]: 0.61; 95% confidence interval [CI]: 0.50-0.75) after adjusting by age, sex and key comorbidities. Similar results were found for cardiovascular hospitalizations (HR: 0.87; 95% CI: 0.76-0.99) and MACEs (HR: 0.84; 95% CI: 0.75-0.95).

CONCLUSION

CPAP treatment continuation could be associated with a significantly lower risk of major cardiovascular events in real-world OSA patients. This result highlights the importance of including real-world patients in studies on OSA.

The Curious Role of PAI-1 in Severe Obstructive Sleep Apnea

Plasminogen activator inhibitor-1 (PAI-1) has a significant role in fibrinolysis, atherogenesis, cellular senescence, and chronic inflammation. OSA (obstructive sleep apnea) leads to increased PAI-1 levels and the development of cardiovascular disease (CVD). The aim of this study was to determine the effects of CPAP therapy on coagulation parameters and PAI-1 in patients with severe OSA. This prospective, controlled study enrolled 57 patients who were newly diagnosed with severe OSA, 37 of whom had had good CPAP adherence after 6 months of therapy (usage of the device for at least 4 h per night), and their data were analyzed. The analysis showed a statistically significant increase in D-dimer values before CPAP therapy (415 (316.5-537.5)) vs. after therapy (499 (327-652)), p = 0.0282, and a decrease in fibrinogen values (3.665 ± 0.752 before CPAP therapy vs. 3.365 ± 0.771 after therapy, p = 0.0075)). PAI-1 concentration values before and after CPAP therapy did not differ significantly (17.35 ± 7.01 ng/mL before CPAP therapy vs. 17.42 ± 6.99 ng/mL after therapy, p = 0.9367). This study shows a tendency for fibrinolytic capacity to improve in patients with OSA after CPAP therapy, although PAI-1 levels did not differ significantly.

Effects of obstructive sleep apnea on myocardial injury and dysfunction: a review focused on the molecular mechanisms of intermittent hypoxia

Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia (IH) and is strongly associated with adverse cardiovascular outcomes. Myocardial injury and dysfunction have been commonly observed in clinical practice, particularly in patients with severe OSA. However, the underlying mechanisms remain obscure. In this review, we summarized the molecular mechanisms by which IH impact on myocardial injury and dysfunction. In brief, IH-induced cardiomyocyte death proceeds through the regulation of multiple biological processes, including differentially expressed transcription factors, alternative epigenetic programs, and altered post-translational modification. Besides cell death, various cardiomyocyte injuries, such as endoplasmic reticulum stress, occurs with IH. In addition to the direct effects on cardiomyocytes, IH has been found to deteriorate myocardial blood and energy supply by affecting the microvascular structure and disrupting glucose and lipid metabolism. For better diagnosis and treatment of OSA, further studies on the molecular mechanisms of IH-induced myocardial injury and dysfunction are essential.

Obstructive sleep apnea heterogeneity and autonomic function: a role for heart rate variability in therapy selection and efficacy monitoring

Obstructive sleep apnea is a highly prevalent sleep-related breathing disorder, resulting in a disturbed breathing pattern, changes in blood gases, abnormal autonomic regulation, metabolic fluctuation, poor neurocognitive performance, and increased cardiovascular risk. With broad inter-individual differences recognised in risk factors, clinical symptoms, gene expression, physiological characteristics, and health outcomes, various obstructive sleep apnea subtypes have been identified. Therapeutic efficacy and its impact on outcomes, particularly for cardiovascular consequences, may also vary depending on these features in obstructive sleep apnea. A number of interventions such as positive airway pressure therapies, oral appliance, surgical treatment, and pharmaceutical options are available in clinical practice. Selecting an effective obstructive sleep apnea treatment and therapy is a challenging medical decision due to obstructive sleep apnea heterogeneity and numerous treatment modalities. Thus, an objective marker for clinical evaluation is warranted to estimate the treatment response in patients with obstructive sleep apnea. Currently, while the Apnea-Hypopnea Index is used for severity assessment of obstructive sleep apnea and still considered a major guide to diagnosis and managements of obstructive sleep apnea, the Apnea-Hypopnea Index is not a robust marker of symptoms, function, or outcome improvement. Abnormal cardiac autonomic modulation can provide additional insight to better understand obstructive sleep apnea phenotyping. Heart rate variability is a reliable neurocardiac tool to assess altered autonomic function and can also provide cardiovascular information in obstructive sleep apnea. Beyond the Apnea-Hypopnea Index, this review aims to discuss the role of heart rate variability as an indicator and predictor of therapeutic efficacy to different modalities in order to optimise tailored treatment for obstructive sleep apnea.

Effect of ventilation modalities on the early prognosis of patients with poststroke sleep apnea

OBJECTIVE

Continuous positive airway pressure (CPAP) is the primary modality for treating sleep apnea after acute ischemic stroke (AIS). However, not all patients are well adherent to CPAP. Finding an alternative modality of ventilation to CPAP is essential.

METHODS

This prospective randomized clinical trial was conducted from 1 May 2022 to 8 January 2023 at the Department of Neurology, Wuhan Union Hospital. Participants diagnosed with sleep apnea after AIS were grouped according to block randomization principles into the usual care group (nasal cannula and facemask), nasal continuous positive airway pressure (nCPAP) group, and high-flow nasal cannula (HFNC) group. Rates of pulmonary infection and endotracheal intubation within 1 week of hospitalization and 28-day mortality (poststroke) were the primary outcomes (early prognosis).

RESULTS

In the trial, 178 patients (119 males [66.85%]; mean [SD] age, 61.04 [11.78] years) were eventually enrolled in the usual care group (n = 63), the nCPAP group (n = 55), and the HFNC group (n = 60). After ventilation, the nCPAP and HFNC groups were more effective than the usual care group in reducing the rate of pulmonary infection, endotracheal intubation, and improving neurological function and sleep apnea severity. However, there was no difference in 28-day mortality. Additionally, the improvement in prognosis was consistent between nCPAP and HFNC. In the comparison of comfort, the HFNC group was superior to nCPAP.

INTERPRETATION

nCPAP and HFNC reduced early pulmonary infection rates and endotracheal intubation rates. For patients with poor compliance with nCPAP, HFNC may be the best alternative.

Impact of Obstructive Sleep Apnea Treatment on Cardiovascular Disease Associated Mortality and Morbidity: A Systematic Review

The association between untreated obstructive sleep apnea (OSA) and cardiovascular disease (CVD) is well known. In this literature review, we aim to review the existing literature on treatment effects of OSA and its impact on CVD morbidity and mortality, stratified by gender. We systematically reviewed PubMed, Medline, and Scopus per PRISMA guidelines and included 25 studies in the final review. Primary outcomes were CVD-associated morbidity and mortality. Out of 25 studies, 10 were meta-analysis, 8 observational, and 7 randomized controlled trials. The treatment modality was continuous positive airway pressure (CPAP) in 23 studies, noninvasive positive pressure ventilation, and oral appliance therapy in 2. Secondary prevention of CVD was the endpoint in 23 studies. A total of 165,775 participants between 45 and 75 years of age, 60%-90% males, and the average Epworth Sleepiness Scale (ESS) score was 5-9. CV outcomes included myocardial infarction, angina, heart failure (HF), acute coronary syndrome (ACS), coronary artery disease (CAD), ischemic heart disease, cardiomyopathy, atrial fibrillation (AF), and hypertension. In 4 studies, CPAP was associated with a reduction in CVD mortality, and 10 studies showed improvement in morbidity. Our review of literature did not show consistent benefits in CV outcomes in OSA patients. We identified many potential research areas, especially the lack of studies demonstrating dose-dependent effect of OSA treatment on CV outcomes, especially when stratified by severity of OSA and gender. Larger prospective studies with longer follow-up will be helpful to study these parameters.

Clinical Application of the Multicomponent Grading System for Sleep Apnea Classification and Incident Cardiovascular Mortality

Objective  To evaluate the clinical utility of the Baveno classification in predicting incident cardiovascular mortality after five years of follow-up in a clinic-based cohort of patients with obstructive sleep apnea (OSA). Materials and Methods  We evaluated the reproducibility of the Baveno classification using data from the Santiago Obstructive Sleep Apnea (SantOSA) study. The groups were labeled Baveno A (minor symptoms and comorbidities), B (severe symptoms and minor comorbidities), C (minor symptoms and severe comorbidities), and D (severe symptoms and comorbidities). Within-group comparisons were performed using analysis of variance (ANOVA) and post hoc tests. The associations between groups and incident cardiovascular mortality were determined through the Mantel-Cox and Cox proportional hazard ratios (HRs) adjusted by covariables. Results  A total of 1,300 OSA patients were included (Baveno A: 27.7%; B: 28%; C: 16.8%; and D: 27.5%). The follow-up was of 5.4 years. Compared to Baveno A, the fully-adjusted risk of cardiovascular mortality with Baveno B presented an HR of 1.38 (95% confidence interval [95%CI]: 0.14-13.5; p  = 0.78); with Baveno C, it was of 1.71 (95%CI: 0.18-16.2; p  = 0.63); and, with Baveno D, of 1.04 (95%CI: 0.12-9.2; p  = 0.98). We found no interactions involving Baveno group, sex and OSA severity. Discussion  Among OSA patients, the Baveno classification can describe different subgroups. However, its utility in identifying incident cardiovascular mortality is unclear. Long-term follow-up studies and the inclusion of demographic variables in the classification could improve its ability to detect a high-risk phenotype associated with cardiovascular mortality. Conclusion  The Baveno classification serves as a valuable method for categorizing varying groups of patients afflicted with OSA. Nevertheless, its precision in identifying occurrence of cardiovascular mortality is still unclear.

Hypoxic burden to guide CPAP treatment allocation in patients with obstructive sleep apnoea: a post hoc study of the ISAACC trial

BACKGROUND

Hypoxic burden (HB) has emerged as a strong predictor of cardiovascular risk in obstructive sleep apnoea (OSA). We aimed to assess the potential of HB to predict the cardiovascular benefit of treating OSA with continuous positive airway pressure (CPAP).

METHODS

This was a post hoc analysis of the ISAACC trial (ClinicalTrials.gov: NCT01335087) including non-sleepy patients with acute coronary syndrome (ACS) diagnosed with OSA (apnoea-hypopnoea index ≥15 events·h-1) by respiratory polygraphy. Patients were randomised to CPAP or usual care and followed for a minimum of 1 year. HB was calculated as the total area under all automatically identified desaturations divided by total sleep time. Patients were categorised as having high or low baseline HB according to the median value (73.1%min·h-1). Multivariable Cox regression models were used to assess whether the effect of CPAP on the incidence of cardiovascular outcomes was dependent on the baseline HB level.

RESULTS

The population (362 patients assigned to CPAP and 365 patients assigned to usual care) was middle-aged (mean age 59.7 years), overweight/obese and mostly male (84.5%). A significant interaction was found between the treatment arm and the HB categories. In the high HB group, CPAP treatment was associated with a significant reduction in the incidence of cardiovascular events (HR 0.57, 95% CI 0.34-0.96). In the low HB group, CPAP-treated patients exhibited a trend toward a higher risk of cardiovascular outcomes than those receiving usual care (HR 1.33, 95% CI 0.79-2.25). The differential effect of the treatment depending on the baseline HB level followed a dose-response relationship.

CONCLUSION

In non-sleepy ACS patients with OSA, high HB levels were associated with a long-term protective effect of CPAP on cardiovascular prognosis.

Mortality in obstructive sleep apnea syndrome (OSAS) and overlap syndrome (OS): The role of nocturnal hypoxemia and CPAP compliance

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD) are two chronic diseases that afflict many individuals worldwide with negative effects on health that may overlap in Overlap Syndrome (OS). The aim of our study was to investigate the differences in mortality between OSAS alone and OS and the risk factors involved.

METHODS

The study was conducted on patients with OSAS or OS diagnosis that completed 15-year follow-up between 2005 and 2023. Of these, the clinical, functional, sleep and survival data were registered and analysed. Risk factors were found by regression analysis.

RESULTS

501 patients (428 OSAS and 73 OS) were enrolled. Patients with OS had higher mortality than OSAS (p < 0,001). The morality risk factors for the overall population found were age >65 years (odds ratio (OR) = 10.69 (95%CI 3,85-29,69), p < 0,001) and low forced-expiratory volume in 1-s (FEV1) (OR = 10.18 (95%CI 2,32-44,68), p = 0,002). In patients with OSAS, age and nocturnal hypoxemia (NH) (OR = 2.41 (95%CI 1,07-5,41), p = 0,03) were risk factors, while adherence to nighttime positive airway pressure (PAP) reduced mortality (OR = 0,36 (95%CI 0,15-0,83), p = 0,017). Multivariate analysis confirmed age and FEV1 as risk factors in OS. Conversely, the risk factors for the overall population under 65 years were NH, which is confirmed in patients with OSAS alone (OR = 4,72 (95%CI 1,07-20,77), p = 0,04) in whom, on the other hand, PAP compliance reduced the mortality risk.

CONCLUSIONS

The study suggests that NH is a risk factor for all-cause mortality in sleep disorders by excluding the age; conversely, nighttime PAP improves the survival.

Effects of continuous positive airway pressure on cardiac events and metabolic components in patients with moderate to severe obstructive sleep apnea and coronary artery disease: a meta-analysis

STUDY OBJECTIVES

This meta-analysis aimed to systematically assess the effects of continuous positive airway pressure (CPAP) in secondary prevention of major cardiovascular events (MACEs) in patients with moderate-to-severe obstructive sleep apnea and coronary artery disease.

METHODS

PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov were searched for observational studies and randomized controlled trials that compared CPAP with usual care in patients with moderate-to-severe obstructive sleep apnea with coronary artery disease. The primary outcomes were MACEs, all-cause death, acute coronary syndrome, rehospitalization for heart failure, repeat revascularization, and arrhythmia.

RESULTS

A total of 11 studies (5 randomized controlled trials and 6 observational studies) with 5,410 patients reported outcomes of MACEs. Treatment with CPAP was associated with a modest risk reduction in MACEs (risk ratio [RR] 0.87, 95% confidence interval [CI] 0.78 to 0.98; P = .02). Similarly, CPAP significantly reduced the risk of all-cause and cardiovascular death by 23% (RR 0.77, 95% CI 0.60 to 0.99; P = .04; I2 = 0%). Subgroup analysis revealed that CPAP adherence time ≥ 4 hours/night had a greater benefit on MACEs by 42% (RR 0.58, 95% CI 0.42 to 0.79; P < .001; I2 = 0%) and repeat revascularization by 44% (RR 0.56, 95% CI 0.34 to 0.92; P = .02; I2 = 0%). Also, CPAP had a positive effect on systolic and diastolic blood pressure.

CONCLUSIONS

CPAP therapy might prevent subsequent MACEs and all-cause death among patients with moderate to severe obstructive sleep apnea and concomitant coronary artery disease. CPAP use exceeding 4 hours/night may add more benefits on MACEs, repeat revascularization, and blood pressure.

CLINICAL TRIAL REGISTRATION

Registry: PROSPERO database; Name: Effects of Continuous Positive Airway Pressure on Cardiovascular Events and Metabolic Components in Patients with Obstructive Sleep Apnea and Coronary Artery Disease; URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID= CRD42020213546; Identifier: CRD42020213546.

CITATION

Yang D, Li L, Dong J, Yang W, Liu Z. Effects of continuous positive airway pressure on cardiac events and metabolic components in patients with moderate to severe obstructive sleep apnea and coronary artery disease: a meta-analysis. J Clin Sleep Med. 2023;19(12):2015-2025.

Multi-Omics Analysis of Circulating Exosomes in Adherent Long-Term Treated OSA Patients

Obstructive sleep apnea (OSA) is a highly prevalent chronic disease affecting nearly a billion people globally and increasing the risk of multi-organ morbidity and overall mortality. However, the mechanisms underlying such adverse outcomes remain incompletely delineated. Extracellular vesicles (exosomes) are secreted by most cells, are involved in both proximal and long-distance intercellular communication, and contribute toward homeostasis under physiological conditions. A multi-omics integrative assessment of plasma-derived exosomes from adult OSA patients prior to and after 1-year adherent CPAP treatment is lacking. We conducted multi-omic integrative assessments of plasma-derived exosomes from adult OSA patients prior to and following 1-year adherent CPAP treatment to identify potential specific disease candidates. Fasting morning plasma exosomes isolated from 12 adult patients with polysomnographically-diagnosed OSA were analyzed before and after 12 months of adherent CPAP therapy (mean ≥ 6 h/night) (OSAT). Exosomes were characterized by flow cytometry, transmission electron microscopy, and nanoparticle tracking analysis. Endothelial cell barrier integrity, wound healing, and tube formation were also performed. Multi-omics analysis for exosome cargos was integrated. Exosomes derived from OSAT improved endothelial permeability and dysfunction as well as significant improvement in tube formation compared with OSA. Multi-omic approaches for OSA circulating exosomes included lipidomic, proteomic, and small RNA (miRNAs) assessments. We found 30 differentially expressed proteins (DEPs), 72 lipids (DELs), and 13 miRNAs (DEMs). We found that the cholesterol metabolism (has04979) pathway is associated with lipid classes in OSA patients. Among the 12 subjects of OSA and OSAT, seven subjects had complete comprehensive exosome cargo information including lipids, proteins, and miRNAs. Multi-omic approaches identify potential signature biomarkers in plasma exosomes that are responsive to adherent OSA treatment. These differentially expressed molecules may also play a mechanistic role in OSA-induced morbidities and their reversibility. Our data suggest that a multi-omic integrative approach might be useful in understanding how exosomes function, their origin, and their potential clinical relevance, all of which merit future exploration in the context of relevant phenotypic variance. Developing an integrated molecular classification should lead to improved diagnostic classification, risk stratification, and patient management of OSA by assigning molecular disease-specific therapies.

Hypoxic Burden Based on Automatically Identified Desaturations Is Associated with Adverse Health Outcomes

Rationale: Recent studies have shown that sleep apnea-specific intermittent hypoxemia quantified by the hypoxic burden (HB) predicted cardiovascular disease (CVD)-related mortality in community-based and clinical cohorts. Calculation of HB is based on manual scoring of hypopneas and apneas, which is time-consuming and prone to interscorer variability. Objective: To validate a novel method to quantify the HB that is based on automatically scored desaturations. Methods: The sample included 5,655 middle-aged or older adults from the Sleep Heart Health Study (52.8% women; age, 63.2 ± 11.3 yr). The original HB method was based on a subject-specific search window obtained from an ensemble average of oxygen saturation signals (as measured by pulse oximetry) and synchronized with respect to the termination of scored respiratory events. In this study, however, the search window was obtained from ensemble average of oxygen saturation signals that synchronized with respect to the minimum of all automatically identified desaturations (⩾2% and other thresholds, including 3% and 4%, in sensitivity analyses). The time interval between the two maxima around the minimum saturation was defined as the search window. The oximetry-derived HB (HBOxi) was defined as the total area under all desaturation curves (restricted by the search window) divided by the total sleep time. Logistic and Cox regression models assessed the adjusted odds ratio (aOR)/hazard ratio of excessive daytime sleepiness (EDS), hypertension (HTN), and CVD mortality per 1-standard deviation increase in HBOxi after adjusting for several covariates and confounders. Results: The Spearman's rank correlation between HB (median [interquartile range], 34.4 [18.4-59.8] % min/h) and HBOxi (median [interquartile range], 34.5 [21.6-53.8] % min/h) was 0.81 (P < 0.001). Similar to HB, HBOxi was significantly associated with EDS (aOR [95% confidence interval (CI)], 1.17 [1.09-1.26] per standard deviation), HTN (aOR [95% CI], 1.13 [1.05-1.21]), and CVD mortality (adjusted hazard ratio [95% CI], 1.15 [1.01-1.30]) in fully adjusted models. Conclusions: The HBOxi was highly correlated with the HB based on manually scored apneas and hypopneas and was associated with EDS, HTN, and CVD mortality with similar effect sizes as previously reported. This method could be incorporated into wearable technology that accurately records oxygen saturation signals.

Adherence to CPAP Treatment and the Risk of Recurrent Cardiovascular Events: A Meta-Analysis

Importance

The effect of continuous positive airway pressure (CPAP) on secondary cardiovascular disease prevention is highly debated.

Objective

To assess the effect of CPAP treatment for obstructive sleep apnea (OSA) on the risk of adverse cardiovascular events in randomized clinical trials.

Data Sources

PubMed (MEDLINE), EMBASE, Current Controlled Trials: metaRegister of Controlled Trials, ISRCTN Registry, European Union clinical trials database, CENTRAL (Cochrane Central Register of Controlled Trials), and ClinicalTrials.gov databases were systematically searched through June 22, 2023.

Study Selection

For qualitative and individual participant data (IPD) meta-analysis, randomized clinical trials addressing the therapeutic effect of CPAP on cardiovascular outcomes and mortality in adults with cardiovascular disease and OSA were included.

Data Extraction and Synthesis

Two reviewers independently screened records, evaluated potentially eligible primary studies in full text, extracted data, and cross-checked errors. IPD were requested from authors of the selected studies (SAVE [NCT00738179], ISAACC [NCT01335087], and RICCADSA [NCT00519597]).

Main Outcomes and Measures

One-stage and 2-stage IPD meta-analyses were completed to estimate the effect of CPAP treatment on risk of recurrent major adverse cardiac and cerebrovascular events (MACCEs) using mixed-effect Cox regression models. Additionally, an on-treatment analysis with marginal structural Cox models using inverse probability of treatment weighting was fitted to assess the effect of good adherence to CPAP (≥4 hours per day).

Results

A total of 4186 individual participants were evaluated (82.1% men; mean [SD] body mass index, 28.9 [4.5]; mean [SD] age, 61.2 [8.7] years; mean [SD] apnea-hypopnea index, 31.2 [17] events per hour; 71% with hypertension; 50.1% receiving CPAP [mean {SD} adherence, 3.1 {2.4} hours per day]; 49.9% not receiving CPAP [usual care], mean [SD] follow-up, 3.25 [1.8] years). The main outcome was defined as the first MACCE, which was similar for the CPAP and no CPAP groups (hazard ratio, 1.01 [95% CI, 0.87-1.17]). However, an on-treatment analysis by marginal structural model revealed a reduced risk of MACCEs associated with good adherence to CPAP (hazard ratio, 0.69 [95% CI, 0.52-0.92]).

Conclusions and Relevance

Adherence to CPAP was associated with a reduced MACCE recurrence risk, suggesting that treatment adherence is a key factor in secondary cardiovascular prevention in patients with OSA.

Efficacy and safety of liraglutide in patients with type 2 diabetes mellitus and severe obstructive sleep apnea

OBJECTIVES

To observe the efficacy and side effects of liraglutide in the treatment of type 2 diabetes mellitus (T2DM) patients with severe obstructive sleep apnea (OSA).

METHODS

The study conducted in an outpatient setting was a two-center, prospective randomized controlled study. T2DM patients with severe OSA were randomized to the control group (continuous positive airway pressure [CPAP] and drug treatment without liraglutide) or the liraglutide group (CPAP and drug treatment including liraglutide). Demographic and clinical characteristics, sleep-disordered breathing indices, cardiac function indices, and side effects were evaluated and compared between the two groups before and after 3 months.

RESULTS

Of 90 patients, 45 were randomized to the intervention arm (with liraglutide) and 45 to the control arm (without liraglutide). One patient in the liraglutide group dropped out of the study on day 8 after enrollment due to obvious gastrointestinal symptoms. No significant differences were found between the two groups in baseline demographics, clinical characteristics, cardiac function indicators, or sleep disorder respiratory indices (P > 0.05). After 3 months, the body mass index (BMI), apnea hypopnea index (AHI), and mean systolic blood pressure in the liraglutide treatment group were significantly lower than those in the control group (P < 0.05). The minimum oxygen saturation was significantly higher in the liraglutide group compared with that in the control group after 3 months of follow-up (P < 0.05). No difference was found between the two groups in the summary of side effects (P > 0.05).

CONCLUSIONS

Liraglutide combined with CPAP can effectively reduce BMI, lower mean systolic blood pressure, and improve AHI scores and hypoxia in T2DM patients with severe OSA. Liraglutide did not increase side effects.

Sleep Apnea Physiological Burdens and Cardiovascular Morbidity and Mortality

Rationale: Obstructive sleep apnea is characterized by frequent reductions in ventilation, leading to oxygen desaturations and/or arousals. Objectives: In this study, association of hypoxic burden with incident cardiovascular disease (CVD) was examined and compared with that of "ventilatory burden" and "arousal burden." Finally, we assessed the extent to which the ventilatory burden, visceral obesity, and lung function explain variations in hypoxic burden. Methods: Hypoxic, ventilatory, and arousal burdens were measured from baseline polysomnograms in the Multi-Ethnic Study of Atherosclerosis (MESA) and the Osteoporotic Fractures in Men (MrOS) studies. Ventilatory burden was defined as event-specific area under ventilation signal (mean normalized, area under the mean), and arousal burden was defined as the normalized cumulative duration of all arousals. The adjusted hazard ratios for incident CVD and mortality were calculated. Exploratory analyses quantified contributions to hypoxic burden of ventilatory burden, baseline oxygen saturation as measured by pulse oximetry, visceral obesity, and spirometry parameters. Measurements and Main Results: Hypoxic and ventilatory burdens were significantly associated with incident CVD (adjusted hazard ratio [95% confidence interval] per 1 SD increase in hypoxic burden: MESA, 1.45 [1.14, 1.84]; MrOS, 1.13 [1.02, 1.26]; ventilatory burden: MESA, 1.38 [1.11, 1.72]; MrOS, 1.12 [1.01, 1.25]), whereas arousal burden was not. Similar associations with mortality were also observed. Finally, 78% of variation in hypoxic burden was explained by ventilatory burden, whereas other factors explained only <2% of variation. Conclusions: Hypoxic and ventilatory burden predicted CVD morbidity and mortality in two population-based studies. Hypoxic burden is minimally affected by measures of adiposity and captures the risk attributable to ventilatory burden of obstructive sleep apnea rather than a tendency to desaturate.

From Snoring to Soaring: Unveiling the Positive Effects of Continuous Positive Airway Pressure Ventilation on Cardiovascular Health in Patients With Obstructive Sleep Apnoea Through a Systematic Review

Increased cardiovascular (CV) morbidity and death are linked to obstructive sleep apnoea (OSA). The primary method of treating OSA is continuous positive airway pressure (CPAP). CPAP has some debatable outcomes on CV events in people suffering from OSA. The current study investigates how CPAP affects CV outcomes. The goal is to evaluate CPAP's effectiveness in lowering CV outcomes in OSA patients. We used a computer to search the PubMed, PubMed Central Library, Science Direct, and Google Scholar databases for studies comparing the effects of CPAP and a control group on CV outcomes in OSA patients. These included randomised control trials (RCT), narrative reviews, systematic reviews, case-control studies, observational studies and meta-analyses. A total of 52,937 patients were included in the final analysis of six RCTs, four observational studies, 10 meta-analyses, one case-control study, two systematic reviews and one narrative review. The weighted mean follow-up lasted for a period of between three months and nine years. The risk of major cardiovascular adverse events (MACE) was the same for both the CPAP and control groups. According to subgroup analysis, patients with lower MACE adherence rates (four hours per night) were more likely to use CPAP. The risk of all-cause mortality, CV-related complications causing mortality, acute myocardial infarction acute stroke, or hospitalisations for angina was the same in the CPAP and control groups. The primary outcome was that in patients with therapy with CPAP in addition to usual care and usual care alone did not prevent CV events in patients with moderate-to-severe OSA and existing CV illness. Patients with OSA who utilise CPAP may not experience fewer CV events. Patients who use CPAP consistently (four hours per night) could benefit from improved CV results. Future research must assess how well-adherent patients with severe OSA and low CV event rates respond to CPAP therapy. In patients who use CPAP for more than four hours each night, CPAP therapy may minimise the risk of MACE and stroke. Additional randomised trials requiring adequate CPAP time adherence are needed to support this perception. Despite the fact that there is no evidence to support the claim that CPAP therapy improves CV outcomes, bias difficulties, CPAP adherence problems, and the patient groups included in each RCT may have made it more difficult to generalise the findings to all patients. Future research is therefore needed to look at these relevant results.

Adherence to positive airway pressure therapy initiated in the early subacute phase of ischemic stroke: a PRESS study follow-up

BACKGROUND

Sleep-disordered breathing (SDB) is frequent in stroke patients and negatively affects stroke outcomes. Positive airway pressure (PAP) is the standard first-line treatment for patients with moderate-to-severe SDB. Despite a strong link between PAP adherence and therapeutic response, rates of post-stroke PAP adherence remain underexplored. Our study aimed to determine PAP adherence in patients undergoing comprehensive sleep apnea assessment and in-lab PAP titration in the early subacute phase of stroke.

METHODS

In-hospital screening pulse oximetry was performed in consecutive patients with imaging-confirmed acute ischemic stroke. Subjects with desaturation index ≥ 15.3/h were selected as PAP candidates, and polysomnography was recommended. In a sleep laboratory setting, subjects underwent a diagnostic night followed by a titration night, and PAP therapy was initiated in subjects with apnea-hypopnea index ≥ 15/h. Adherence to PAP therapy was assessed at a 6-month follow-up visit.

RESULTS

Of 225 consecutive patients with acute ischemic stroke, 116 were PAP candidates and 52 were able to undergo polysomnography. PAP therapy was initiated in 35 subjects. At a 6-month follow-up visit, out of 34 stroke survivors, PAP adherence (PAP use of > 4 h per night) was present in 47%. Except for the significantly lower minimal nocturnal O2 saturation determined from the polysomnography (74.6 ± 11.7% vs. 81.8 ± 5.2%, p = 0.025), no other significant difference in characteristics of the groups with PAP adherence and PAP non-adherence was found.

CONCLUSIONS

Less than half of the stroke subjects remained adherent to PAP therapy at 6 months post-PAP initiation. Special attention to support adaptation and adherence to PAP treatment is needed in this group of patients.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Effect of different ventilation modalities on the early prognosis of patients with sleep apnea after acute ischemic stroke---protocol for a prospective, open-label and randomised controlled trial

BACKGROUND

Sleep apnea is highly prevalent after acute ischemic stroke (AIS) and has increased stroke-related mortality and morbidity. The conventional sleep apnea treatment is continuous positive airway pressure (CPAP) ventilation. However, it is poorly tolerated by patients and is not used in all stroke patients. This protocol describes the impact of high-flow nasal cannula (HFNC) oxygen therapy compared to nasal continuous positive airway pressure (nCPAP) ventilation or usual care on the early prognosis of patients with sleep apnea after AIS.

METHODS

This randomised controlled study will be conducted in the intensive care unit of the Department of Neurology at the Wuhan Union Hospital. According to the study plan, 150 patients with sleep apnea after AIS will be recruited. All patients are randomly allocated in a 1:1:1 ratio to one of three groups: the nasal catheter group (standard oxygen group), the HFNC group, and the nCPAP group. Patients receive different types of ventilation after admission to the group, and their tolerance while using the different ventilation is recorded. Patients will be followed up by telephone three months after discharge, and stroke recovery is recorded. The primary outcomes were 28-day mortality, the incidence of pulmonary infection and endotracheal intubation.

DISCUSSION

This study analyses different ventilation modalities for early interventions in patients with sleep apnea after AIS. We will investigate whether nCPAP and HFNC reduce early mortality and endotracheal intubation rates and improve distant neurological recovery in patients.

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov (NCT05323266; 25 March 2022).

Effects of Antihypertensive Treatment on Left and Right Ventricular Global Longitudinal Strain and Diastolic Parameters in Patients with Hypertension and Obstructive Sleep Apnea: Randomized Clinical Trial of Chlorthalidone plus Amiloride vs. Amlodipine

Hypertension is highly prevalent in patients with obstructive sleep apnea (OSA), and fluid retention with its nighttime rostral distribution is one potential mechanism. We tested whether or not diuretics differ from amlodipine in their impact on echocardiographic parameters. Patients with moderate OSA and hypertension were randomized to receive diuretics (chlorthalidone plus amiloride) or amlodipine daily for 8 weeks. We compared their effects on left and right ventricular global longitudinal strain (LV-GLS and RV-GLS, respectively), on LV diastolic parameters, and on LV remodeling. In the 55 participants who had echocardiographic images feasible for strain analysis, all echocardiographic parameters were within normal ranges. After 8 weeks, the 24 h blood pressure (BP) reduction values were similar, while most echocardiographic metrics were kept unchanged, except for LV-GLS and LV mass. In conclusion, the use of diuretics or amlodipine had small and similar effects on echocardiographic parameters in patients with moderate OSA and hypertension, suggesting that they do not have important effects on mediating the interaction between OSA and hypertension.

Obstructive sleep apnea and cardiovascular events in acute coronary syndrome: a meta-analysis

OBJECTIVE

Obstructive sleep apnea (OSA) in patients with the acute coronary syndrome (ACS) were at high risk for cardiovascular events, but the results are currently inconclusive. We aimed to conduct a systematic review to determine the incidence of cardiovascular events among ACS patients with OSA by a meta-analysis of observational studies.

METHODS

PubMed, Embase, and Cochrane Library were searched for studies related to the association between OSA and the risk of cardiovascular events in patients with ACS. Risk of bias in observational studies was assessed according to the Risk Of Bias In the Non-randomized Studies-Of Interventions tool.We performed a meta-analysis using a random-effects model to calculate estimates of pooled hazard ratios (HR) with 95% confidence intervals (CI), and heterogeneity was assessed using the statistics.

RESULTS

A total of 12 studies evaluating ACS patients with OSA were included in the meta-analysis. OSA was related to the increased risk of MACE (HR = 2.2; 95% CI, 1.274-3.805, I2  = 76.1%). The effect of OSA on MACCE (HR = 1.921; 95% CI, 1.45-2.546; I2  = 19.1%) and readmission for unstable angina (HR = 3.137, 95% CI, 1.06-9.283; I2  = 52.4%) were statistically significant in the pooled analysis. All of the outcomes in the included studies had a serious risk of bias and the Grading of Recommendation, Assessment, Development, and Evaluation evidence level of all the evaluation results were very low.

CONCLUSIONS

OSA was associated with a significant increase in the risk of cardiovascular events for patients with ACS. Additional randomized controlled trial studies are required to confirm the results and to prove the treatment of OSA can change the prognosis.

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.

Prognostic importance of obstructive sleep apnea and CPAP treatment for cardiovascular and mortality outcomes in patients with resistant hypertension: a prospective cohort study

The prognostic importance of obstructive sleep apnea (OSA) severity and other polysomnographic parameters in patients with resistant hypertension (RHT) has never been evaluated. We aimed to assess it in a prospective cohort of 422 individuals with RHT. OSA presence/severity was ascertained by complete polysomnography (PSG) at baseline. Multivariable Cox regressions assessed the risks associated with OSA severity and other PSG parameters (apnea-hypopnea index, sleep duration, nocturnal hypoxemia and periodic limb movements) for the primary (total cardiovascular events [CVEs] and all-cause mortality) and secondary outcomes (major CVEs). In the subgroup of patients with moderate/severe OSA, the risks associated with CPAP treatment were also estimated in relation to untreated individuals. One-hundred and eighty-six participants (44%) had no/mild OSA and 236 (56%) had moderate/severe OSA, and 67 of them were CPAP-treated. Over a mean follow-up of 5 years, there were 46 CVEs (37 major ones) and 44 all-cause deaths. Neither the presence of moderate/severe or severe OSA, nor being untreated during follow-up, was associated with significant excess risks for any outcome in relation to the subgroup with no/mild OSA. Similarly, no other PSG-derived parameter predicted any adverse outcome. Otherwise, CPAP treatment was associated with non-significant risk reductions of 37% for total CVEs, 49% for major CVEs and 63% for all-cause mortality in relation to those who remained untreated during follow-up. In conclusion, the presence/severity of OSA and its related PSG parameters were not associated with worse cardiovascular/mortality prognosis in patients with RHT. However, CPAP treatment might be protective in individuals with moderate/severe OSA.

Gut microbiota mediate vascular dysfunction in a murine model of sleep apnoea: effect of probiotics

BACKGROUND

Obstructive sleep apnoea (OSA) is a chronic prevalent condition characterised by intermittent hypoxia (IH), and is associated with endothelial dysfunction and coronary artery disease (CAD). OSA can induce major changes in gut microbiome diversity and composition, which in turn may induce the emergence of OSA-associated morbidities. However, the causal effects of IH-induced gut microbiome changes on the vasculature remain unexplored. Our objective was to assess if vascular dysfunction induced by IH is mediated through gut microbiome changes.

METHODS

Faecal microbiota transplantation (FMT) was conducted on C57BL/6J naïve mice for 6 weeks to receive either IH or room air (RA) faecal slurry with or without probiotics (VSL#3). In addition to 16S rRNA amplicon sequencing of their gut microbiome, FMT recipients underwent arterial blood pressure and coronary artery and aorta function testing, and their trimethylamine N-oxide (TMAO) and plasma acetate levels were determined. Finally, C57BL/6J mice were exposed to IH, IH treated with VSL#3 or RA for 6 weeks, and arterial blood pressure and coronary artery function assessed.

RESULTS

Gut microbiome taxonomic profiles correctly segregated IH from RA in FMT mice and the normalising effect of probiotics emerged. Furthermore, IH-FMT mice exhibited increased arterial blood pressure and TMAO levels, and impairments in aortic and coronary artery function (p<0.05) that were abrogated by probiotic administration. Lastly, treatment with VSL#3 under IH conditions did not attenuate elevations in arterial blood pressure or CAD.

CONCLUSIONS

Gut microbiome alterations induced by chronic IH underlie, at least partially, the typical cardiovascular disturbances of sleep apnoea and can be mitigated by concurrent administration of probiotics.

Shared decision making: A novel approach to personalized treatment in obstructive sleep apnea

Study objectives

i) To describe a novel approach of phenotyping by shared decision making (SDM) in obstructive sleep apnea (OSA) discharge consultations ii) to describe correlation between patient and observer based evaluations of SDM and iii) to describe treatment adherence.

Methods

Consecutive patients referred to the otorhinolaryngology department at Akershus University Hospital with suspected OSA between 2015 and 2016 participated. Patients with body mass index >30 were oversampled. Four male communication-trained doctors aged from 30 to 60 years participated. SDM was evaluated by modified content analysis and by the CollaboRATE self-report questionnaire and the “Observer OPTION (Young et al., 2008) [5]” rating scale. Positive airway pressure (PAP) treatment adherence and weight reduction was assessed by interview at six year follow-up.

Results

Eighteen consultations were video filmed. The content analysis revealed that the patient perspectives only briefly were explored. PAP was chosen by 17 of 18 patients. Median CollaboRATE questionnaire score was 29 (26, 30). Mean OPTION (Young et al., 2008) [5] score was 65.6 (SD 6.6, range 55–80). The correlation between SDM assessed by CollaboRATE self-report and by the “Observer OPTION (Young et al., 2008) [5]” rating scale was low (Pearson's r = 0.09). At follow up, 11 patients (64.7%) were PAP adherent and no one achieved 10% weight loss.

Conclusions

Despite a high degree of SDM compared to studies of non-OSA populations, the sub-optimal exploration of the patient perspective by communication-trained doctors precluded identification of patients willing to cope actively. SDM assessed by self-report and by a rating scale may represent two different constructs. PAP adherence was good.

•

Obstructive sleep apnea treatment adherence is a clinical challenge.

•

Little is known about the use of phenotyping by shared decision making in sleep research.

•

Phenotyping by shared decision making was found to occur, but the patient perspective was discussed to a small extent.

•

The CollaboRATE questionnaire is not optimal due to a ceiling effect for assessing shared decision making among patients with obstructive sleep apnea.

A Review of a Recent Meta-Analysis Study on Obstructive Sleep Apnea

This paper summarizes a recent meta-analysis of various topics in obstructive sleep apnea (OSA). In addition to cardiovascular disease and neurocognitive dysfunction, a wide variety of diseases have been associated with OSA, and associations with cancer have also been reported. Although continuous positive airway pressure is a very effective treatment, the results have shown that it does not reduce the incidence of various complications. It has been reported that uvulopalatopharyngoplasty was effective, and robotic surgery for the tongue root and hypoglossal nerve stimulation were also effective. The effectiveness of various medications to reduce daytime sleepiness has also been demonstrated. Although exercise lowered the apnea-hypopnea index, it was not related to changes in body composition, and it was also reported that exercise combined with weight control were effective. Additionally, interesting and clinically meaningful meta-analysis results were summarized and presented.

Prevalence of High Blood Pressure in Pediatric Patients with Sleep-Disordered Breathing, Reversibility after Treatment: The KIDS TRIAL Study Protocol

Current data support an increase in the prevalence of high blood pressure (HBP) in pediatric patients with sleep-disordered breathing (SDB). Adeno-tonsillectomy has been shown to be an effective treatment for most patients. Our objective was to determine the prevalence of HBP in pediatric patients with SDB and the impact of adeno-tonsillectomy with a multicenter, longitudinal, and prospective study that included 286 children referred for suspected SDB. The diagnosis of SDB was established by polysomnography (PSG) and the diagnosis of HBP by 24-h ambulatory blood pressure monitoring (ABPM). In patients without SDB and SDB without treatment indication, these tests were repeated six months after the baseline visit. For patients with medical treatment for SDB, the tests were repeated six months after the treatment initiation. Finally, in patients with surgery indication, ABPM was performed just before surgical treatment and ABPM and PSG six months after the intervention. The study contributes to elucidating the association between SDB and HBP in pediatric patients. Moreover, it contributes to determining if intervention with adeno-tonsillectomy is associated with BP reduction. The results have direct implications for the management of SDB, providing essential information on treatment indications for existing clinical guidelines. NCT03696654.

Impact of CPAP Therapy on New Inflammation Biomarkers

Obstructive sleep apnea (OSA) is a common sleep disorder leading to increased risk of developing cardiovascular diseases (CVDs) by supporting a low-grade chronic inflammation as one of the pathological mechanisms. The continuous positive airway pressure (CPAP) device is used as an effective treatment for moderate and severe OSA. Neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), white blood cell–mean platelet volume ratio (WMR), C-reactive protein–albumin ratio (CAR) and fibrinogen–albumin ratio (FAR) are new potential inflammatory biomarkers that are widely available and were shown to be possibly favorable screening or follow-up tools for moderate- or severe-grade OSA, as well as indirect indicators for cardiovascular risk. Our study evaluated the impact of CPAP therapy in patients with severe OSA and acceptable therapy adherence on NLR, PLR, WMR, FAR and CAR. Of 57 patients who were initially enrolled and had no exclusion criteria, 37 had a satisfactory CPAP adherence (usage of ≥4 h per night) after a minimum of 6 months of therapy. There was a statistically significant difference in NLR (2.122 ± 0.745 before therapy vs. 1.888 ± 0.735 after therapy) and FAR (86.445 ± 18.763 before therapy vs. 77.321 ± 19.133 after therapy) suggesting a positive effect of the CPAP therapy on chronic inflammatory states, thereby possibly reducing cardiovascular risk.

Temporal changes in coronary artery function and flow velocity reserve in mice exposed to chronic intermittent hypoxia

Study Objectives

Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH) that is implicated in an increased risk of cardiovascular disease (i.e., coronary heart disease, CHD) and associated with increased overall and cardiac-specific mortality. Accordingly, we tested the hypothesis that experimental IH progressively impairs coronary vascular function and in vivo coronary flow reserve.

Methods

Male C57BL/6J mice (8-week-old) were exposed to IH (FiO2 21% 90 s–6% 90 s) or room air (RA; 21%) 12 h/day during the light cycle for 2, 6, 16, and 28 weeks. Coronary artery flow velocity reserve (CFVR) was measured at each time point using a Doppler system. After euthanasia, coronary arteries were micro-dissected and mounted on wire myograph to assess reactivity to acetylcholine (ACh) and sodium nitroprusside (SNP).

Results

Endothelium-dependent coronary relaxation to ACh was preserved after 2 weeks of IH (80.6 ± 7.8%) compared to RA (87.8 ± 7.8%, p = 0.23), but was significantly impaired after 6 weeks of IH (58.7 ± 16.2%, p = 0.02). Compared to ACh responses at 6 weeks, endothelial dysfunction was more pronounced in mice exposed to 16 weeks (48.2 ± 5.3%) but did not worsen following 28 weeks of IH (44.8 ± 11.6%). A 2-week normoxic recovery after a 6-week IH exposure reversed the ACh abnormalities. CFVR was significantly reduced after 6 (p = 0.0006) and 28 weeks (p &lt; 0.0001) of IH when compared to controls.

Conclusion

Chronic IH emulating the hypoxia-re-oxygenation cycles of moderate-to-severe OSA promotes coronary artery endothelial dysfunction and CFVR reductions in mice, which progressively worsen until reaching asymptote between 16 and 28 weeks. Normoxic recovery after 6 weeks exposure reverses the vascular abnormalities.

Continuous positive airway pressure reduces the incidence of atrial fibrillation in patients with obstructive sleep apnea: A Meta-Analysis and Systematic Review

INTRODUCTION

Obstructive sleep apnea (OSA) and atrial fibrillation (AF) are disorders that have increased in the United States during recent years. Earlier investigations have shown that underlying undiagnosed and unmanaged OSA plays a significant role in high rates and also as a trigger for newly diagnosed AF. Since the introduction of continuous positive airway pressure (CPAP) as a main therapy for OSA, more studies have evaluated the effect of CPAP on the development or recurrence of AF in OSA patients. However, sample sizes in a limited number of studies have been too small to conclude whether CPAP therapy has a significant effect on the development of AF in patients with OSA. The authors report results of their systematic review and meta-analysis summarizing what is currently known about the efficacy of CPAP for mitigating AF in patients with OSA.

METHOD

The authors systematically reviewed the published reports on CPAP use and the incidence of AF from PubMed, Google Scholar, EMBASE, Web of Science, meeting abstracts, and Cochrane databases published between January 2015 and November 2021. Study data were extracted by two reviewers and a random-effects meta-analysis was performed using RevMan version 5.4.

RESULTS

A total of 17 studies that met inclusion criteria were identified Studies included a total of 6,523 patients, 3,248 (49.8%) who used CPAP and 3,275 (50.2%) who did not use CPAP. In a random effects model, patients treated with CPAP showed a decrease in the incidence of AF (OR, 0.51; 95% CI; 0.27; 0.97, p = 0.04). High heterogeneity among the included studies was also observed (I2 = 97%).

CONCLUSION

Our results add to the increasing evidence that CPAP therapy may reduce the incidence of development of AF in patients with OSA. Prospective future studies and clinical trials are needed to refine our understanding of the relationship between OSA and AF and how CPAP may reduce cardiovascular disease development.

Investigation of the Effectiveness of Traditional Breathing Therapy on Pulmonary Function in College Students with Obstructive Sleep Apnea

Background

Obstructive sleep apnea (OSA) is a problem that involves many body systems, but its impact on the respiratory system deserves special attention. While there are many studies investigating the use of continuous positive airway pressure (CPAP) to treat lung function in patients with sleep apnea, the lack of studies in the literature on the effects of traditional breathing therapy on lung function in patients with OSA prompted us to conduct such a study.

Objective

The present randomized trial aims to assess the effect of traditional breathing therapy on daytime sleepiness and pulmonary function in college students with OSA.

Methods

Forty college students (male) with OSA were randomly divided into two groups: the control group (CG) and the traditional breathing therapy group (TG). Daytime sleepiness symptoms in OSA are measured primarily by the Epworth Sleepiness Scale (ESS). Pulmonary function measurements included FVC, FEV1, PEE, and MEF50%. The changes in morning blood pressure (BP), including diastolic BP and systolic BP, were also recorded. Data were recorded before and after the experiment.

Results

A decrease in ESS at 12 weeks after intervention had statistical significance compared with values recorded before intervention (P < 0.05). A decrease in systolic and diastolic BP at 12 weeks after intervention had statistical significance compared with values recorded before intervention (P < 0.05). Comparisons made in terms of pulmonary functions demonstrated a statistically significant increase in 12-week postintervention values of FVC, FEV1, PEF, and MEF50% (P < 0.05).

Conclusion

Our study shows the positive effects of traditional breathing therapy on pulmonary function parameters. This suggests that traditional breathing therapy treatment in OSA patients is as effective as CPAP on pulmonary function, while there is an improvement in daytime sleepiness and a modest decline in the mean daytime systolic and diastolic BP.

Risk of Cardiovascular Disease in Apnoeic Individuals: Role of Comorbid Insomnia Disorder

Given the limited data available, the aim of this study was to examine the 10-year cardiovascular disease (CVD) risk associated with comorbid insomnia disorder and its specific subtypes in apnoeic individuals. Data from 1104 apnoeic individuals recruited from the database of the Erasme Hospital Sleep Laboratory were analysed. Only apnoeic individuals with a Framingham Risk Score ≥10% were included in the group at moderate-to-high 10-year CVD risk. Logistic regression analyses were conducted to examine the risk of 10-year CVD risk associated with comorbid insomnia disorder and its specific subtypes in apnoeic individuals. Moderate-to-high 10-year CVD risk was present in 59.6% of the apnoeic individuals in our sample. After adjustment for the main confounding factors, multivariate logistic regression analyses revealed that comorbid insomnia disorder and, more particularly, its subtype with short sleep duration were significantly associated with moderate-to-high 10-year CVD risk in apnoeic individuals. In this study, we demonstrate that comorbid insomnia disorder and, more specifically, its subtype with short sleep duration appear to have a negative cumulative effect on 10-year CVD risk in apnoeic individuals, which justifies more systematic research and adequate therapeutic management of this disorder to allow for better cardiovascular disease prevention in this particular subpopulation.

The impact of continuous positive airway pressure on cardiac mechanics: Findings from a meta-analysis of echocardiographic studies

Current evidence on the effects of continuous positive airway pressure (CPAP) on cardiac mechanics in patients with obstructive sleep apnea (OSA) is based on a few single studies. The authors investigated this topic through a meta‐analysis of speckle tracking echocardiography (STE) studies that provided data on left ventricular (LV) and right ventricular (RV) mechanics as assessed by global longitudinal strain (GLS). The PubMed, OVID‐MEDLINE, and Cochrane library databases were systematically analyzed to search English‐language review papers published from inception to January 31, 2022. Studies were identified by crossing the following terms: “obstructive sleep apnea”, “sleep quality”, “sleep disordered breathing”, “continuous positive airway pressure therapy”, “noninvasive ventilation”, “left ventricular hypertrophy”, “systolic dysfunction”, “global longitudinal strain”, “left ventricular mechanics”, “right ventricular mechanics”, “echocardiography” and “STE echocardiography”. The meta‐analysis, including a total of 337 patients with OSA from nine studies (follow‐up 2–24 months) showed a significant GLS improvement in both LV and RV after CPAP, standard mean difference (SMD) being 0.51±0.08, CI:0.36–0.66, p = .0001 and 0.28±0.07, CI:0.15–0.42, p = .0001), respectively. Corresponding SMD values for LV ejection fraction (LVEF) and tricuspid annular plane systolic excursion (TAPSE) were 0.20±0.06, CI:0.08–0.33, p = .001 and 0.08±0.06, CI: ‐0.04/0.20, p = .21. Our meta‐analysis suggests that: I) CPAP treatment exerts beneficial effects on biventricular function in patients with OSA; II) the assessment of cardiac mechanics by STE should be routinely recommended for monitoring cardiac function in this setting, due to limitations of conventional echocardiography in evaluating biventricular performance.

Relationship Between CPAP Termination and All-Cause Mortality: A French Nationwide Database Analysis

BACKGROUND

Randomized controlled trials have failed to demonstrate an effect of CPAP therapy on mortality. However, these studies have a number of important limitations, including low CPAP adherence, patient selection, and a small number of mortality events.

RESEARCH QUESTION

What are the effects of CPAP therapy termination in the first year on all-cause mortality in patients with OSA from the Nationwide Claims Data Lake for Sleep Apnea study?

STUDY DESIGN AND METHODS

Data from the Système National des Données de Santé (SNDS) database, the French national health insurance reimbursement system, for all new CPAP users ≥ 18 years of age were analyzed. The SNDS contains comprehensive, individualized, and anonymized data on health spending reimbursements for > 99% of all individuals living in France. OSA diagnosis was based on specific disease codes, whereas CPAP prescription was identified using specific treatment method codes. CPAP therapy termination was defined as the cessation of CPAP reimbursements triggered by the respiratory physician or sleep specialist in charge of follow-up. Patients who terminated therapy in the first year were propensity score matched with those who continued to use CPAP. The primary outcome was all-cause mortality. Three-year survival was visualized using Kaplan-Meier curves. Contributors to mortality also were determined.

RESULTS

Data from two matched groups each including 88,007 patients were included (mean age, 60 years; 64% men). Continuation of CPAP therapy was associated with a significantly lower risk of all-cause death compared with CPAP therapy termination (hazard ratio [HR], 0.61; 95% CI, 0.57-0.65; P < .01, log-rank test). Incident heart failure also was less common in patients who continued vs terminated CPAP therapy (HR, 0.77; 95% CI, 0.71-0.82; P < .01).

INTERPRETATION

These real-world data from a comprehensive, unbiased database highlight the potential for ongoing use of CPAP treatment to reduce all-cause mortality in patients with OSA.

Current and Novel Treatment Options for OSA

Obstructive sleep apnoea is a challenging medical problem due to its prevalence, its impact on quality of life and performance in school and professionally, the implications for risk of accidents, and comorbidities and mortality. Current research has carved out a broad spectrum of clinical phenotypes and defined major pathophysiological components. These findings point to the concept of personalised therapy, oriented on both the distinct clinical presentation and the most relevant pathophysiology in the individual patient. This leads to questions of whether sufficient therapeutic options other than positive airway pressure (PAP) alone are available, for which patients they may be useful, if there are specific indications for single or combined treatment, and whether there is solid scientific evidence for recommendations. This review describes our knowledge on PAP and non-PAP therapies to address upper airway collapsibility, muscle responsiveness, arousability and respiratory drive. The spectrum is broad and heterogeneous, including technical and pharmaceutical options already in clinical use or at an advanced experimental stage. Although there is an obvious need for more research on single or combined therapies, the available data demonstrate the variety of effective options, which should replace the unidirectional focus on PAP therapy.

The analysis of individual pathophysiological composition opens new directions towards personalised treatment of OSA, focusing not only on pharyngeal dilation, but also on technical or pharmaceutical interventions on muscle function or breathing regulationhttps://bit.ly/3sayhkd

A new design of mandibular advancement device (IMYS) in the treatment of obstructive sleep apnea

OBJECTIVE

The mandibular advancement device (MAD) is currently suggested in patients with mild to moderate obstructive sleep apnea (OSA). This study investigated the effects of a new fully customizable MAD-type device called, "It Makes You Sleep" (IMYS), in patients with mild to moderate OSA.

METHODS

Sixteen patients (14 men and 2 women; mean age 62; SD ± 11 years) were retrospectively enrolled. Each patient received home sleep apnea testing (HSAT) at baseline (T0) and after three months (T1) of IMYS treatment. The Apnea-Hypopnea Index (AHI), the Oxygen Desaturation Index (ODI), the Minimum Oxygen Saturation (minSO2) and the Medium Oxygen Saturation (medSO2) were analyzed.

RESULTS

From T0 to T1, the IMYS treatment showed a significant reduction of AHI and ODI and a significant increase of minSO2 and medSO2.

CONCLUSION

The IMYS appliance is an effective device for treating mild or moderate OSA.

Weight reduction added to CPAP decreases blood pressure and triglyceride level in OSA: systematic review and meta-analysis

Obstructive sleep apnea (OSA) is associated with treatment‐resistant hypertension and high cardiovascular risk. Continuous positive airway pressure (CPAP) fails to reduce cardiovascular risks consistently. Obesity and OSA show reciprocal association and they synergistically increase hypertension via different pathways. Our meta‐analysis aimed to assess the cardiovascular benefits of combining weight loss (WL) with CPAP (vs. WL or CPAP alone) in OSA. Outcomes included systolic and diastolic blood pressure (BP) and blood lipid parameters. We explored Medline, Embase, Cochrane, and Scopus. Eight randomized controlled studies (2627 patients) were included. The combined therapy decreased systolic BP more than CPAP alone. Weighted mean difference (WMD) for CPAP + WL versus CPAP was −8.89 mmHg, 95% confidence interval (95% CI; −13.67 to −4.10, p < 0.001) for systolic BP. For diastolic BP, this decrease was not significant. In case of blood lipids, the combined treatment decreased triglyceride levels more than CPAP alone (WMD = −0.31, 95% CI −0.58 to −0.04, p = 0.027). On the other hand, addition of CPAP to WL failed to suppress BP further. The certainty of evidence according to GRADE was very low to moderate. In conclusion, our results showed that the addition of WL to CPAP significantly improved BP and blood lipid values in OSA. On the other hand, the addition of CPAP to WL could not significantly improve BP or blood lipid values. Review protocol: PROSPERO CRD42019138998.

Prevalence, types and treatment of bradycardia in obstructive sleep apnea - A systematic review and meta-analysis

BACKGROUND

The association of obstructive sleep apnea (OSA) with bradycardia is not well-characterized, which may confer significant morbidity and mortality if left untreated. We sought to clarify the prevalence of comorbid OSA and bradycardia, and the effect of continuous positive airway pressure (CPAP) therapy on bradycardia outcomes.

METHODS

We systematically searched four electronic databases (PubMed, Embase, Cochrane Library, Scopus) for randomized or observational studies reporting the co-prevalence of sleep apnea and bradycardia or evaluated the use of CPAP on the incidence of bradycardias. We used random-effects models in all meta-analyses and evaluated heterogeneity using I².

RESULTS

We included 34 articles from 7204 records, comprising 4852 patients. Among patients with OSA, the pooled prevalence of daytime and nocturnal bradycardia were 25% (95% CI: 18.6 to 32.7) and 69.8% (95% CI: 41.7 to 88.2) respectively. Among patients with bradycardia, the pooled prevalence of OSA was 56.8% (95% CI: 21.5 to 86.3). CPAP treatment, compared to those without, did not significantly reduce the risk of daytime (two randomized trials; RR: 0.50; 95% CI: 0.11 to 2.21) or nocturnal bradycardia (one randomized-controlled trial and one cohort study; RR: 0.76; 95% CI: 0.48 to 1.20).

CONCLUSIONS

This meta-analysis demonstrates a high comorbid disease burden between OSA and bradycardia. Future research should explore the treatment effect of CPAP on bradycardia incidence, as compared to placebo.

Speckle tracking echocardiography in heart failure development and progression in patients with apneas

Obstructive (OA) and central apneas (CA) are highly prevalent breathing disorders that have a negative impact on cardiac structure and function; while OA promote the development of progressive cardiac alterations that can eventually lead to heart failure (HF), CA are more prevalent once HF ensues. Therefore, the early identification of the deleterious effects of apneas on cardiac function, and the possibility to detect an initial cardiac dysfunction in patients with apneas become relevant. Speckle tracking echocardiography (STE) imaging has become increasingly recognized as a method for the early detection of diastolic and systolic dysfunction, by the evaluation of left atrial and left and right ventricular global longitudinal strain, respectively. A growing body of evidence is available on the alterations of STE in OA, while very little is known with regard to CA. In this review, we discuss the current knowledge and gap of evidence concerning apnea-related STE alterations in the development and progression of HF.

MicroRNA Sequencing Analysis in Obstructive Sleep Apnea and Depression: Anti-Oxidant and MAOA-Inhibiting Effects of miR-15b-5p and miR-92b-3p through Targeting PTGS1-NF-κB-SP1 Signaling

The aim of this study was to identify novel microRNAs related to obstructive sleep apnea (OSA) characterized by intermittent hypoxia with re-oxygenation (IHR) injury. Illumina MiSeq was used to identify OSA-associated microRNAs, which were validated in an independent cohort. The interaction between candidate microRNA and target genes was detected in the human THP-1, HUVEC, and SH-SY5Y cell lines. Next-generation sequencing analysis identified 22 differentially expressed miRs (12 up-regulated and 10 down-regulated) in OSA patients. Enriched predicted target pathways included senescence, adherens junction, and AGE-RAGE/TNF-α/HIF-1α signaling. In the validation cohort, miR-92b-3p and miR-15b-5p gene expressions were decreased in OSA patients, and negatively correlated with an apnea hypopnea index. PTGS1 (COX1) gene expression was increased in OSA patients, especially in those with depression. Transfection with miR-15b-5p/miR-92b-3p mimic in vitro reversed IHR-induced early apoptosis, reactive oxygen species production, MAOA hyperactivity, and up-regulations of their predicted target genes, including PTGS1, ADRB1, GABRB2, GARG1, LEP, TNFSF13B, VEGFA, and CXCL5. The luciferase assay revealed the suppressed PTGS1 expression by miR-92b-3p. Down-regulated miR-15b-5p/miR-92b-3p in OSA patients could contribute to IHR-induced oxidative stress and MAOA hyperactivity through the eicosanoid inflammatory pathway via directly targeting PTGS1-NF-κB-SP1 signaling. Over-expression of the miR-15b-5p/miR-92b-3p may be a new therapeutic strategy for OSA-related depression.

Obstructive sleep apnea and stroke: The mechanisms, the randomized trials, and the road ahead

When considered separately from cardiovascular disease, stroke is the third leading cause of death in the U.S. and is the leading cause of long-term disability in adults. New approaches that can be offered to the majority of ischemic stroke patients, can be continued throughout post-stroke care, can limit stroke severity, and can complement or even enhance rehabilitation, would transform ischemic stroke recovery. The treatment of obstructive sleep apnea (OSA) in patients with acute ischemic stroke may represent one such approach. This manuscript reviews the epidemiologic studies of the bidirectional association between OSA and stroke, and the mechanisms and molecular signatures of OSA leading to transient ischemic attack and stroke as well as the randomized controlled trials and observational cohort studies examining continuous positive airway treatment efficacy on the impact of stroke outcomes. Finally, the insights these studies provide on future research are also discussed.