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

Assessment and management of continuous positive airway pressure therapy in patient with obstructive sleep apnea

Obstructive sleep apnea (OSA) causes excessive daytime sleepiness, impaired daytime functioning, and an increased risk of cardiovascular diseases. Continuous positive airway pressure (CPAP) is a highly effective therapy for moderate to severe OSA. Although CPAP adherence is commonly assessed using a 4-hthreshold, determining the optimal usage time based on clinical outcomes is crucial. While subjective sleepiness often improves with ≥4 h of CPAP usage, an extended duration (≥6 h) may be necessary to impact objective sleepiness. CPAP demonstrated a modest yet clinically meaningful dose-dependent effect on lowering blood pressure. For patients seeking antihypertensive benefits from CPAP therapy, the goal should extend beyond 4 h of use to maximize the therapeutic impact. Recognizing individual variations in sleep duration and responses to CPAP therapy is essential. The adoption of 'individualized goals for CPAP use,' outlining target times for specific outcomes, should also consider an individual's total sleep duration, including periods without CPAP. The impact of CPAP on clinical outcomes may vary, even with the same duration of CPAP use, depending on the period without CPAP use, particularly during the first or second half of sleep. Patients who remove or initiate CPAP midway or have a low CPAP usage frequency may require different forms of guidance. Tailoring patient education to address CPAP usage patterns may be necessary to enhanced satisfaction, self-efficacy, and adherence to therapy. Management of CPAP treatment should be personalized to meet individual needs and adapted based on specific response patterns for achieving treatment efficacy.

Association between sleep duration during pregnancy and gestational diabetes mellitus: a systematic review and meta-analysis

Objective

To systematically review studies on the correlation between sleep duration during pregnancy and gestational diabetes mellitus (GDM) and use meta-analysis to explore the correlation between the two to provide a basis for preventing GDM during pregnancy.

Methods

The search databases were China Knowledge Network (CNKI), Weipu, Wanfang, China Biomedical Literature Service System (SinoMed), Cochrane Library, Web of Science, Embase, and PubMed, and the search time was from the establishment of the above databases to July 2023. The data were statistically analyzed using STATA/MP17 and RevMan 5.3 software. Publication bias could be accurately assessed using funnel plots and Egger's test.

Results

A total of 5,197 papers were searched, and 13 studies were finally included, which included 80,259 individuals, including 3,461 patients with GDM. The comprehensive analysis showed that. Based on pooled data from prospective, cross-sectional, and case-control studies, extreme sleep duration during pregnancy was strongly associated with GDM compared with average sleep duration. The results of the prospective studies showed that both short (OR = 1.50, 95% CI: 1.07-2.10, I2 = 60.9%, p = 0.02) and long (OR = 1.28, 95% CI: 1.13-1.46, I2 = 0.0%, p < 0.0001) sleep duration increased the risk of gestational diabetes mellitus, but the harms were more pronounced with short sleep. In analyzing the association between extreme sleep duration and GDM, publication bias was found in prospective, cross-sectional, and case-control studies with moderate heterogeneity and prospective-only studies with low heterogeneity.

Conclusion

Both too short and too long sleep duration during pregnancy are strongly associated with GDM. Either too short or too long sleep duration predicts the risk of developing GDM, but the harms are more pronounced with short sleep. These findings remind us of the importance of controlling sleep duration during pregnancy and help to optimize early strategies to prevent GDM.Systematic review registration: http://www.crd.york.ac.uk/prospero, identifier [CRD42023470925].

Correlation between obstructive sleep apnea and hypoperfusion in patients with acute cerebral infarction

Purpose

To explore the relationship between obstructive sleep apnea (OSA) and hypoperfusion during ultra-early acute cerebral infarction.

Patients and methods

Data were retrospectively collected from patients admitted to our hospital with acute cerebral infarction between January 2020 and January 2022, who underwent comprehensive whole-brain computed tomography perfusion imaging and angiography examinations within 6 h of onset. The F-stroke software automatically assessed and obtained relevant data (Tmax). The patients underwent an initial screening for sleep apnea. Based on their Apnea-Hypopnea Index (AHI), patients were categorized into an AHI ≤15 (n = 22) or AHI >15 (n = 25) group. The pairwise difference of the time-to-maximum of the residue function (Tmax) > 6 s volume was compared, and the correlation between AHI, mean pulse oxygen saturation (SpO2), oxygen desaturation index (ODI), percentage of time with oxygen saturation < 90% (T90%), and the Tmax >6 s volume was analyzed.

Results

The Tmax >6 s volume in the AHI > 15 group was significantly larger than that in the AHI ≤ 15 group [109 (62-157) vs. 59 (21-106) mL, p = 0.013]. Spearman's correlation analysis revealed Tmax >6 s volume was significantly correlated with AHI, mean SpO2, ODI, and T90% in the AHI > 15 group, however, no significant correlations were observed in the AHI ≤ 15 group. Controlling for the site of occlusion and Multiphase CT angiography (mCTA) score, AHI (β = 0.919, p < 0.001), mean SpO2 (β = -0.460, p = 0.031), ODI (β = 0.467, p = 0.032), and T90% (β =0.478, p = 0.026) remained associated with early hypoperfusion in the AHI > 15 group.

Conclusion

In patients with acute cerebral infarction and AHI > 15, AHI, mean SpO2, ODI and T90% were associated with early hypoperfusion. However, no such relationship exists among patients with AHI ≤ 15.

Obstructive Sleep Apnea and Stroke: Determining the Mechanisms Behind their Association and Treatment Options

Sleep-disordered breathing (SDB) can be a sequela of stroke caused by vascular injury to vital respiratory centers, cerebral edema, and increased intracranial pressure of space-occupying lesions. Likewise, obstructive sleep apnea (OSA) contributes to increased stroke risk through local mechanisms such as impaired ischemic cerebrovascular response and systemic effects such as promoting atherosclerosis, hypercoagulability, cardiac arrhythmias, vascular-endothelial dysfunction, and metabolic syndrome. The impact of OSA on stroke outcomes has been established, yet it receives less attention in national guidelines on stroke management than hyperglycemia and blood pressure dysregulation. Furthermore, whether untreated OSA worsens stroke outcomes is not well-described in the literature. This scoping review provides an updated investigation of the correlation between OSA and stroke, including inter-relational pathophysiology. This review also highlights the importance of OSA treatment and its role in stroke outcomes. Knowledge of pathophysiology, the inter-relationship between these common disorders, and the impact of OSA therapy on outcomes affect the clinical management of patients with acute ischemic stroke. In addition, understanding the relationship between stroke outcomes and pre-existing OSA will allow clinicians to predict outcomes while treating acute stroke.

Heart Failure, Investigator-Reported Sleep Apnea and Dapagliflozin: A Patient-Level Pooled Meta-Analysis of DAPA-HF and DELIVER

BACKGROUND

Sleep apnea is more common in patients with heart failure (HF) than in the general population, but little is known about its association with clinical outcomes in various HF phenotypes or how it might modify the effect of HF therapy.

OBJECTIVES

To examine the prevalence of sleep apnea, its association with outcomes and the effects of dapagliflozin in patients with HF with and without sleep apnea in a pooled analysis of 2 trials comparing dapagliflozin to placebo in HFrEF (DAPA-HF trial) and HFmrEF/HFpEF (DELIVER trial).

METHODS

A history of sleep apnea was investigator-reported. The primary outcome was a composite of worsening HF or cardiovascular death.

RESULTS

The prevalence of sleep apnea was 5.7% and 7.8% in patients with HFrEF and HFmrEF/HFpEF, respectively. The primary outcome occurred at a rate of 16.0 in participants with sleep apnea compared to 10.6 per 100 person-years in those without (adjusted HR 1.29 [95%CI, 1.10-1.52]). Compared with placebo, dapagliflozin reduced the risk of the primary endpoint to the same extent in patients with (HR 0.78 [95% CI, 0.59-1.03]) and without sleep apnea (HR 0.79 [0.72-0.87]) [Pinteraction = 0.93]. The beneficial effects of dapagliflozin on other clinical outcomes and symptom burden, physical function, and quality of life were consistent in participants with and without sleep apnea.

CONCLUSIONS

In DAPA-HF and DELIVER, the true prevalence of sleep apnea was likely underestimated. An investigator-reported history of sleep apnea was associated with higher rates of worsening HF events. The benefits of dapagliflozin on clinical outcomes were consistent in patients with and without sleep apnea.

CLINICAL TRIAL REGISTRATION

Unique identifiers: NCT01920711 CONDENSED ABSTRACT: In a pooled analysis of the DAPA-HF and DELIVER trials of more than 11,000 patients with heart failure (HF) across the range of ejection fractions, an investigator-reported history of sleep apnea was associated with higher rates of worsening HF events but not mortality. The beneficial effects of dapagliflozin on clinical outcomes were consistent in patients with and without sleep apnea. These findings provide further evidence for dapagliflozin as a new treatment option for patients with heart failure across the range of ejection fractions.

Pulmonary Function Tests Post-Stroke. Correlation between Lung Function, Severity of Stroke, and Improvement after Respiratory Muscle Training

Stroke is a significant cause of mortality and chronic morbidity caused by cardiovascular disease. Respiratory muscles can be affected in stroke survivors, leading to stroke complications, such as respiratory infections. Respiratory function can be assessed using pulmonary function tests (PFTs). Data regarding PFTs in stroke survivors are limited. We reviewed the correlation between PFTs and stroke severity or degree of disability. Furthermore, we reviewed the PFT change in stroke patients undergoing a respiratory muscle training program. We searched PubMed until September 2023 using inclusion and exclusion criteria in order to identify studies reporting PFTs post-stroke and their change after a respiratory muscle training program. Outcomes included lung function parameters (FEV1, FVC, PEF, MIP and MEP) were measured in acute or chronic stroke survivors. We identified 22 studies of stroke patients, who had undergone PFTs and 24 randomised controlled trials in stroke patients having PFTs after respiratory muscle training. The number of patients included was limited and studies were characterised by great heterogeneity regarding the studied population and the applied intervention. In general, PFTs were significantly reduced compared to healthy controls and predicted normal values and associated with stroke severity. Furthermore, we found that respiratory muscle training was associated with significant improvement in various PFT parameters and functional stroke parameters. PFTs are associated with stroke severity and are improved after respiratory muscle training.

Age-related differences in the association of mild-to-moderate sleep apnea with incident cardiovascular and cerebrovascular diseases

BACKGROUND

Mild-to-moderate obstructive sleep apnea (mmOSA) is highly prevalent in the general population. However, studies on its association with incident cardiovascular and/or cerebrovascular disease (CBVD) are limited. We examined the association between mild-to-moderate OSA and incident cardiovascular and/or cerebrovascular (CBVD) in a general population sample, and whether age modifies this association.

METHODS

A total of 1173 adults from the Penn State Adult Cohort (20-88 years) without CBVD or severe OSA at baseline were followed-up after 9.2 (±4.1) years. Incident CBVD was defined based on a self-report of a physician diagnosis or treatment for heart disease and/or stroke. Logistic regression examined the association of mild-to-moderate OSA (AHI 5-29.9) with incident CBVD and the combined effect of mmOSA and MetS on incident CBVD after adjusting for multiple confounders.

RESULTS

Age significantly modified the association between mmOSA with incident CBVD (p-interaction = 0.04). Mild-to-moderate OSA was significantly associated with incident CBVD in adults aged <60 years (OR = 1.74, 95%CI = 1.06-2.88, p = 0.029), but not in adults aged ≥60 years (OR = 0.71, 95%CI = 0.39-1.27, p = 0.247). Even mild OSA (AHI 5-14.9) carried a significant risk for incident CBDV in adults aged <60 years (OR = 1.86, 95%CI = 1.05-3.28, p = 0.032). An additive effect was found between mmOSA and MetS with incident CBVD in those aged <65 years (OR = 3.84, 95%CI = 1.95-7.56, p<0.001).

CONCLUSIONS

The risk of incident CBVD is increased in young and middle-aged but not older adults with mmOSA, which may affect the way we currently diagnose and treat this highly prevalent sleep-related breathing disorder.

Blood pressure control in hypertensive sleep apnoea patients of the European Sleep Apnea Database cohort - effects of positive airway pressure and antihypertensive medication

Aims

We analysed longitudinal blood pressure (BP) data from hypertensive obstructive sleep apnoea (OSA) patients in the European Sleep Apnea Database cohort. The study investigated the interaction between positive airway pressure (PAP)-induced BP change and antihypertensive treatment (AHT).

Methods and results

Hypertensive patients with AHT [monotherapy/dual therapy n = 1283/652, mean age 59.6 ± 10.7/60.6 ± 10.3 years, body mass index (BMI) 34.2 ± 6.5/34.8 ± 7.0 kg/m2, apnoea-hypopnoea index 46 ± 25/46 ± 24 n/h, proportion female 29/26%, respectively] started PAP treatment. Office BP at baseline and 2- to 36-month follow-up were assessed. The interaction between AHT drug classes and PAP on BP was quantified and the influences of age, gender, BMI, co-morbidities, BP at baseline, and study site were evaluated. Following PAP treatment (daily usage, 5.6 ± 1.6/5.7 ± 1.9 h/day), systolic BP was reduced by -3.9 ± 15.5/-2.8 ± 17.7 mmHg in mono/dual AHT and diastolic BP by -3.0 ± 9.8/-2.7 ± 10.8 mmHg, respectively, all P < 0.0001. Systolic and diastolic BP control was improved following PAP treatment (38/35% to 54/46% and 67/67% to 79/74%, mono/dual AHT, respectively). PAP treatment duration predicted a larger BP improvement in the monotherapy group. Intake of renin-angiotensin blockers [angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB)] alone or in any AHT combination was associated with better BP control. The AHT-dependent BP improvement was independent of confounders.

Conclusion

In this pan-European OSA patient cohort, BP control improved following initiation of PAP. Longer PAP treatment duration, was associated with a favourable effect on BP. Our study suggests that ACEI/ARB, alone or in combination with other drug classes, provides a particularly strong reduction of BP and better BP control when combined with PAP in OSA.

Research trends and hotspots regarding treatment of obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is a type of sleep-disordered breathing disease, with high prevalence and multiple complications. It seriously affects patients' quality of life and even threatens their lives. Early and effective treatment can significantly improve patients' health conditions.

Objective

In this study, the main treatment methods, research hotspots and trends of OSA were summarized through bibliometric and visualization analysis.

Methods

From the Web of Science Core Collection database, articles on the treatment of OSA from 1999 to 2022 were obtained. CiteSpace and VOSviewer were comprehensively used to visualization of journals, co-authorship of countries, institutions and authors, co-citation of references, keywords cluster and burst.

Results

A total of 2,874 publications were obtained, of which 2,584 were concerned adults and 290 about children. In adults' research, Sleep and Breathing is the most published journal (280, 10.84%), the largest number of publications come from the United States (636,24.61%) and the University of Sydney (88, 3.41%), and Pepin JL is the most published author (48, 18.58%). In children's studies, International Journal of Pediatric Otorhinolaryngology is the most published journal (41, 14.14%), the maximum number of publications were also from the United States (123, 42.41%), with the University of Pennsylvania (20, 6.90%) and Marcus CL (15, 5.17%) being the most published institutions and authors. High-frequency keywords for adults' researches include positive airway pressure, oral appliance, surgery and positional therapy. On these basis, children's studies also focus on myofunctional therapy, rapid maxillary expansion and hypoglossal nerve Stimulation.

Conclusion

Over the past two decades, research in the field of OSA therapeutics has experienced significant growth in depth and breadth. The author cooperation network has already established a solid foundation, while there is potential for further strengthening the cooperation network between countries and institutions. Currently, positive airway pressure and surgery are the primary treatments for OSA in adults and children. Future research will focus on multidisciplinary combination targeted therapy, which presents a key area of interest and challenge.

Limited Palatal Muscle Resection for the Treatment of Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

Background and Objectives: Limited palatal muscle resection (PMR) is a surgical technique employed to alleviate respiratory disturbances in obstructive sleep apnea (OSA) patients with retropalatal narrowing by reducing soft palate volume and tightening the muscles. Although some previous publications have demonstrated the effectiveness of limited PMR, the overall efficacy and therapeutic role of limited PMR for the treatment of OSA remain uncertain. This study utilized meta-analysis and a systematic literature review to estimate the overall effectiveness of limited PMR in treating OSA. Materials and Methods: Multiple databases, including PubMed, EMBASE, Cochrane Library, and Web of Science, were searched using specific keywords related to OSA and limited PMR. Original articles assessing respiratory disturbances before and after limited PMR in patients with OSA were included. Data from selected articles were collected using standardized forms, including clinicodemographic characteristics, apnea-hypopnea index (AHI), and lowest pulse oximetry values (minimum SpO2). Random effect models were used for analyzing significant heterogeneity. Egger's test and funnel plot were used to identify publication bias. Results: Four studies were included in this meta-analysis for AHI, and three studies were included for minimum SpO2 during sleep. A significant reduction in the AHI and an increase in the minimum SpO2 were shown following limited PMR as the standardized mean difference (95% confidence interval) was 2.591 (1.092-4.090) and 1.217 (0.248-2.186), respectively. No publication bias was found in either analysis. Conclusions: The results of the meta-analysis and systemic review add to the literature that limited PMR can result in a reduction in the AHI and an increase in min SaO2. In OSA patients with suspected retropalatal obstruction, limited PMR may be efficiently performed.

Modified STOP-bang questionnaire incorporating morning dry mouth and BMI adjustment in China: a retrospective study of 590 patients

BACKGROUND

Morning dry mouth (MDM) is a common symptom of Obstructive Sleep Apnea (OSA) yet current OSA screening tools overlook it.

OBJECTIVE

To enhance the specificity of the Stop-Bang questionnaire (SBQ) by adding an MDM symptom.

METHOD

A retrospective analysis on 590 patients from Peking University First Hospital (2013-2018) suspected of OSA was conducted. They underwent polysomnography. The research incorporated the MDM symptom into SBQ and adjusted the body mass index (BMI) threshold to 28 kg/m2. Predictive parameters were then calculated.

RESULTS

83.1% patients were diagnosed with OSA, with 61.4% reporting MDM. Multivariate regression confirmed MDM significantly influenced Apnea-Hypopnea Index (AHI). Adjusted SBQ with MDM showed a slight decrease in sensitivity but improved specificity, especially when using a BMI threshold of > 28 kg/m2. For AHI ≥ 5 events/h and AHI ≥ 15 events/h, adjusted SBQ with MDM (BMI >28 kg/m2) obtained the highest Youden index.

CONCLUSION

Incorporating the MDM symptom into SBQ and adjusting the BMI threshold enhances the diagnostic specificity for OSA.

Obstructive sleep apnea modulates clinical outcomes post-acute myocardial infarction: A large longitudinal veterans' dataset report

BACKGROUND

While the longer-term Obstructive Sleep apnea (OSA)-related intermittent hypoxia (IH) leads to various comorbidities, it has become increasingly evident that OSA confers protective advantages during and after acute myocardial infarction (AMI). We hypothesized in patients who were admitted with acute MI, the presence of OSA is associated with lower in-hospital mortality compared to those without a prior diagnosis of OSA.

METHODS

In this nationwide retrospective study utilizing Veterans Health Administration records, we included patients hospitalized for MI with a history of sleep disorders from 1999 to 2020. We divided patients into two cohorts: those with OSA and those without OSA. The primary outcome was in-hospital mortality during AMI hospitalization. We analyzed the data using logistic regression and calculated the odds ratio of in-hospital mortality.

RESULTS

Out of more than four million veterans with any sleep diagnosis, 76,359 patients were hospitalized with a diagnosis of AMI. We observed 30,116 with OSA (age, 64 ± 10 years; BMI, 33 ± 7 kg/m2) and 43,480 without OSA (age, 68 ± 12 years; BMI, 29 ± 6 kg/m2). The aOR of in-patient mortality (n = 333 (1.1%)) was lower in those with OSA (aOR, 0.43; 95% CI, 0.38 to 0.49) compared to without-OSA (n = 1,102, 2.5%). However, the OSA cohort had a higher proportion of the prolonged length of stay (28.1%).

CONCLUSIONS

Presence of OSA is associated with lower in-hospital mortality among patients admitted for AMI, after adjusting for various demographic and co-morbidity factors. This study highlights the complex relationship between OSA and cardiovascular health and highlights the need for further research in this area.

Clinical significance of obstructive sleep apnea in patients with acute coronary syndrome with or without prior stroke: a prospective cohort study

BACKGROUND AND OBJECTIVE

Whether obstructive sleep apnea (OSA) is associated with worse prognosis in patients with acute coronary syndrome (ACS) with or without prior stroke remains unclear. We investigated the association of OSA with cardiovascular events in ACS patients with or without prior stroke.

METHODS

Between June 2015 and January 2020, we prospectively recruited eligible ACS patients who underwent cardiorespiratory polygraphy during hospitalization. We defined OSA as an apnea hypopnea index (AHI) ≥ 15 events/hour. The primary composite end point was major adverse cardiovascular and cerebrovascular events (MACCEs), including cardiovascular death, myocardial infarction, stroke, ischemia-driven revascularization, or hospitalization for unstable angina or heart failure.

RESULTS

Among 1927 patients enrolled, 207 patients had prior stroke (10.7%) and 1014 had OSA (52.6%). After a mean follow-up of 2.9 years, patients with stroke had significantly higher risk of MACCEs than those without stroke (hazard ratio [HR]:1.49; 95% confidence interval [CI]: 1.12-1.98, P = 0.007). The multivariate analysis showed that patients with OSA had 2.0 times the risk of MACCEs in prior stroke group (41 events [33.9%] vs 18 events [20.9%]; HR:2.04, 95% CI:1.13-3.69, P = 0.018), but not in non-prior stroke group (186 events [20.8%] vs 144 events [17.4]; HR:1.21, 95% CI 0.96-1.52, P = 0.10). No significant interaction was noted between prior stroke and OSA for MACCE (interaction P = 0.17).

CONCLUSIONS

Among ACS patients, the presence of OSA was associated with an increased risk of cardiovascular events in patients with prior stroke. Further trials exploring the efficacy of OSA treatment in high-risk patients with ACS and prior stroke are warranted. Trial registration Clinicaltrials.gov identifier NCT03362385.

[The relationship of vascular complications with cerebrovascular reactivity and endothelial dysfunction in patients with obstructive sleep apnea]

OBJECTIVE

To assess the relationship of vascular complications with cerebrovascular reactivity (CVR) and endothelial dysfunction in patients with obstructive sleep apnea (OSA).

MATERIAL AND METHODS

One hundred and twelve patients were examined. The patients were stratified into the main group with moderate and severe OSA and the control group without apnea. All patients underwent anthropometry, polysomnography, transcranial dopplerography and duplex scanning of the brachial artery.

RESULTS

Patients with OSA showed a more frequent decrease in post-occlusive vascular dilatation. The CVR indices in the hypercapnic test in the main group were in the range of 0.91-0.97 and significantly lower after 1 minute on the left, after 5 minutes on both sides and after 10 minutes on the left. A positive correlation during a hypercapnic test between the CVR on the left after 10 minutes and the desaturation index (r=0.287, p=0.021), between the CVR on the left after 5 and 10 minutes and acute cerebrovascular accident (r=0.248, p=0.048 and r=0.285, p=0.022, respectively), as well as a negative correlation between the indicators of the middle cerebral artery and chronic cerebral ischemia were established in patients with apnea.

CONCLUSION

Timely assessment of pathological changes in central and peripheral hemodynamics in patients with OSA will allow diagnosing early signs of vascular complications, which will further improve the personalized strategy for the prevention of stroke and chronic cerebral ischemia.

The J-shape Association between Total Bilirubin and Stroke in Older Patients with Obstructive Sleep Apnea Syndrome: A Multicenter Study

OBJECTIVES

To explore the relationship between total bilirubin (TBil) and stroke risk in older patients with obstructive sleep apnea syndrome (OSAS).

METHODS

A total of 1,007 patients with OSAS without stroke history aged ≥ 60 years and with complete serum TBil records were enrolled in this study. The median follow-up was 42 months. Participants were divided into four groups based on the quartile of the baseline serum TBil concentration. Multivariate Cox proportional hazards analysis and restricted cubic spline (RCS) were used to investigate the association of TBil with the incidence of new-onset stroke.

RESULTS

The PRIMARY part: the third quantile TBil level group had the lowest prevalence of stroke among the four groups. The RCS functions depicted a J-type curve relationship between TBil (3.3-33.3 µmol/L) and stroke (nonlinear P < 0.05). When the TBil level was in the range of 3.3 to 11.5 µmol/L, the possible protective influence of bilirubin against stroke in patients with OSAS enhanced with an increasing TBil level. However, when the TBil level exceeded 11.5 µmol/L and gradually increased, the effect of TBil on stroke risk became more and more pronounced. The SECONDARY part: for every 1 µmol/L increase in TBil levels in the range of 11.5 to 33.3 µmol/L, the risk of stroke in patients with OSAS increased by 16.2% (P < 0.001). In addition, there was a higher risk in women with OSAS (hazard ratio (HR)=1.292, 95% confidence interval (95%CI): 1.093-1.528; P = 0.003). Moreover, an increased TBil level alone was significantly associated with stroke in subjects aged < 75 years (HR: 1.190, 95%CI: 1.069-1.324), patients with mild-to-moderate OSAS (HR: 1.215, 95%CI: 1.083-1.364), and individuals without atrial fibrillation (AF) (HR: 1.179, 95%CI: 1.083-1.285) within a TBil level in the range of 11.5 to 33.3 µmol/L.

CONCLUSIONS

Both lower and higher bilirubin levels may increase the risk of stroke in older persons with OSAS, and there was a J-type dose-response relationship. The risk of stroke was lowest when the TBil level was approximately 11.5 µmol/L.

Causal Relations Between Obstructive Sleep Apnea and Stroke: A Mendelian Randomization Study

Background

Previous studies of obstructive sleep apnea (OSA) in relation to stroke have been noted. However, the exact causality remains to be clearly defined. We aimed to adopt a two-sample Mendelian randomization study to investigate the causal effects of OSA on stroke and its subtypes.

Methods

A two-sample Mendelian randomization (MR) analysis was conducted to evaluate the causal effect of OSA on stroke and its subtypes, including, based on publicly genome-wide association studies (GWAS) databases. The inverse variance weighted (IVW) method was used as the main analysis. MR-Egger regression, weighted mode, weighted median, and MR pleiotropy residual sum and outlier (MR-PRESSO) were performed methods and were adopted as supplementary analysis to ensure the robustness of the results.

Results

Genetically predicted OSA was not related to the risk of stroke (odds ratio (OR), 0.99, 95% CI, 0.81-1.21, p = 0.909), and its subtypes, ischemic stroke (IS) (OR, 1.01, 95% CI, 0.82-1.23, p = 0.927), large vessel stroke (LVS) (OR, 1.05, 95% CI, 0.73-1.51, p = 0.795), cardioembolic stroke (CES) (OR, 1.03, 95% CI, 0.74-1.43, p = 0.855), small vessel stroke (SVS) (OR, 1.13, 95% CI, 0.88-1.46, p = 0.329), lacunar stroke (LS) (OR, 1.07, 95% CI, 0.74-1.56, p = 0.721) as well as intracerebral hemorrhage (ICH) (OR, 0.37, 95% CI = 0.09, 1.48, p = 0.160) (Wald ratio method). Other supplementary MR methods also confirmed similar results.

Conclusion

There may be no direct causal relationship between OSA and stroke or its subtypes.

Hypertension treatment in patients with sleep apnea from the European Sleep Apnea Database (ESADA) cohort - towards precision medicine

We recruited 5,970 hypertensive patients with obstructive sleep apnea (OSA) on current antihypertensive treatment from the European Sleep Apnea Database (ESADA) cohort. The group was subdivided into those receiving monotherapy (n = 3,594) and those receiving dual combined therapy (n = 2,376). We studied how major OSA confounders like age, gender, and body mass index as well as the degree of sleep apnea modified office systolic and diastolic blood pressure. Beta-blockers alone or in combination with a diuretic were compared with other antihypertensive drug classes. Monotherapy with beta-blocker was associated with lower systolic blood pressure, particularly in non-obese middle-aged males with hypertension. Conversely, the combination of a beta-blocker and a diuretic was associated with lower systolic and diastolic blood pressure in hypertensive patients with moderate-severe OSA. Systolic blood pressure was better controlled in female patients using this combined treatment. Our cross-sectional data suggest that specific clinical characteristics and type of antihypertensive medication influence the degree of blood pressure control in hypertensive OSA patients. Controlled trials are warranted.

Differences in the prevalence of cardiovascular and metabolic diseases coinciding with clinical subtypes of obstructive sleep apnea

BACKGROUND

It is unclear about the cardiovascular and metabolic diseases (CMD) among Chinese patients with different clinical subtypes of obstructive sleep apnea (OSA).

HYPOTHESIS

The prevalence of CMD varies among OSA patients of different clinical subtypes.

METHODS

A total of 1483 Chinese patients with OSA were assessed to evaluate the existence of clinical subtypes of OSA using latent class analysis. We compared the differences in demographic characteristics and prevalence of CMD using ANOVA and χ² tests. Associations between clinical subtypes and disease prevalence were assessed using adjusted logistic regression.

RESULTS

We identified prevalent CMD in Chinese patients with the four subtypes of OSA: excessively sleepy (ES), moderately sleepy with disturbed sleep (ModSwDS), moderately sleepy (ModS), and minimally symptomatic (MinS). The ES subtype had a higher body mass index, average Epworth Sleepiness Scale score, Apnea-hypopnea index, and oxyhemoglobin saturation below 90% compared with the other subtypes (p < .05). The MinS subtype had the lowest mean ESS score (p < .05). We found a significant difference in the prevalence of CMD among the four subtypes, with the highest proportion of cases of CMD in the ES subtype. In adjusted models, significant associations with CMD were also found. ES, ModSwDS, ModS, and MinS subtypes are very high-risk, high-risk, medium-risk, and low-risk in prevalent CMD.

CONCLUSIONS

This study identified four clinical subtypes of OSA in Chinese patients. Each clinical subtype corresponds with a different level of prevalence of CMD; this finding is helpful for the more precise treatment of patients with different clinical manifestations.

Sleep and breathing disorders in heart failure

Sleep disorders are prevalent in heart failure and include insomnia, poor sleep architecture, periodic limb movements and periodic breathing, and encompass both obstructive (OSA) and central sleep apnea (CSA). Polysomnographic studies show excess light sleep and poor sleep efficiency particularly in those with heart failure. Multiple studies of consecutive patients with heart failure show that about 50% of patients suffer from either OSA or CSA. While asleep, acute pathological consequences of apneas and hypopneas include altered blood gases, sleep fragmentation, and large negative swings in intrathoracic pressure. These pathological consequences are qualitatively similar in both types of sleep apnea, though worse in OSA than CSA. Sleep apnea results in oxidative stress, inflammation, and endothelial dysfunction, best documented in OSA. Multiple studies show that both OSA and CSA are associated with excess hospital readmissions and premature mortality. However, no randomized controlled trial (RCT) has been reported for OSA, but sensitivity analysis of two randomized controlled trials has concluded that use of positive airway pressure devices is associated with excess mortality in patients with heart failure and CSA. Phrenic nerve stimulation has shown improvement in sleep apnea events and daytime sleepiness; however, no randomized controlled trials have demonstrated improvement in survival in patients with heart failure. The correct identification and treatment of heart failure patients with sleep and breathing disorders could affect the long-term outcomes of these patients.