Obstructive Sleep Apnea as a Cardiovascular Risk Factor-Beyond CPAP

The impact of continuous positive airway pressure therapy on cardiovascular events in patients with obstructive sleep apnoea: an updated systematic review and meta-analysis

OBJECTIVE

Obstructive sleep apnoea (OSA) is positively associated with cardiovascular diseases, and continuous positive airway pressure (CPAP) is a common treatment for such patients. This study aimed to explore the impact of CPAP on cardiovascular outcomes and prognosis in patients with OSA.

METHODS

A search was conducted in the PubMed, Embase and CENTRAL databases for relevant studies published up to March 2024. Two independent reviewers screened the studies based on inclusion and exclusion criteria, and data were synthesised using RevMan 5.3 software. Heterogeneity was assessed using the Cochran Q test and the I2 statistic.

RESULTS

A total of 10 randomised controlled trials and 3 observational studies, comprising 13,832 patients, were included. Compared with standard treatment, the use of CPAP did not significantly reduce the risk of major adverse cardiovascular events (MACE) (risk ratio [RR]: 0.73, 95% confidence interval [CI]: 0.52-1.03; p = 0.07; I2 = 66%), all-cause mortality (RR: 0.92, 95% CI: 0.72-1.16; p = 0.48; I2 = 0%), cardiovascular mortality (RR: 0.63, 95% CI: 0.33-1.19; p = 0.15; I2 = 70%) or non-cardiovascular mortality (RR: 0.81, 95% CI: 0.57-1.15; p = 0.23; I2 = 0%). Similarly, there were no significant differences in the incidence of myocardial infarction, stroke, hospitalisation due to unstable angina or heart failure or atrial fibrillation among those using CPAP. However, when CPAP adherence was ≥ 4 h, CPAP significantly reduced the risk of MACE and cardiovascular mortality.

CONCLUSION

Although CPAP's cardiovascular benefits in patients with OSA are not confirmed, it may be that bias risks, CPAP adherence and characteristics of the study population may attenuate the perceived benefits of CPAP. Further research is needed to optimise CPAP therapy.

Higher ambient temperatures may worsen obstructive sleep apnea: A nationwide smartwatch-based analysis of 6.2 million person-days

Obstructive sleep apnea (OSA) is a serious type of sleep disorder that can lead to cardiometabolic and neurocognitive diseases. We utilized smart device-based photoplethysmography technology to collect sleep data from the Chinese population from 2019 to 2022. Distributed lag nonlinear models combined with a generalized nonlinear model or a linear mixed effects model were used to investigate the short-term associations between daily temperature and indicators of OSA severity. We included a total of 6,232,056 d of sleep monitoring data from 51,842 participants with moderate to severe risk of OSA from 313 Chinese cities. The relationships between ambient temperature and OSA exacerbation, apnea-hypopnea index (AHI), and minimum oxygen saturation (MinSpO2) were almost linear and present only on the same day. Higher temperatures were associated with a greater risk of OSA exacerbation, with an 8.4% (95% confidence interval (CI): 7.6%-9.3%) increase per 10 °C increase in temperature. A 10 °C increase in daily temperature corresponded to an AHI increase of 0.70 events/h (95% CI: 0.65-0.76) and a MinSpO2 decrease of 0.18% (95% CI: 0.16%-0.19%). Exposure to elevated temperatures during the night can also lead to adverse effects. The effects of higher temperatures on OSA severity were stronger among men, participants with a body mass index ≥ 24 kg/m2, those aged 45 years and older, individuals with a history of hypertension and diabetes, and during the cold season. This large-scale, nationwide, longitudinal study provides robust evidence suggesting that higher ambient temperatures may immediately worsen OSA.

Continuous positive airway pressure therapy might be an effective strategy on reduction of atrial fibrillation recurrence after ablation in patients with obstructive sleep apnea: insights from the pooled studies

Background

Obstructive sleep apnea (OSA) is an independent and modifiable risk factor in the initiation and maintenance of atrial fibrillation (AF). However, the effective of the continuous positive airway pressure (CPAP) on AF patients with OSA after ablation is elusive.

Methods

Cochrane Library, PubMed, Embase, and Web of Science were systematically searched up to February 1, 2023. Studies comprising the AF recurrence rate between the CPAP therapy group and non-CPAP therapy group for the AF patients with OSA were included. Meanwhile, trial sequential analysis (TSA) was conducted to adjust the lower statistical power and random error in this study. Subgroup analysis identified the potential determinants for the AF recurrence rate with CPAP therapy.

Results

A total of eight studies including 1,231 AF patients with OSA were eligible. Compared with non-CPAP treatment group, CPAP treatment group was statistically associated with a lower AF recurrence rate (risk ratio [RR], 0.58; p = 0.000). TSA indicated the firm evidence favoring CPAP group for AF recurrence risk. Three significant intervention-covariate interactions for AF recurrence was identified, including study design, non-paroxysmal AF (PAF) proportion, and CPAP treatment strategy.

Conclusion

Our study suggests that CPAP therapy might be an effective strategy on reducing AF recurrence post-ablation for AF patients with OSA. The CPAP treatment strategy and the non-PAF proportion might be the possible determinants on AF recurrence for AF patients with OSA after ablation.

Clinical trial registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023398588, identifier (CRD42023398588).

Nomogram to diagnosis of obstructive sleep apnoea-hypopnoea syndrome in high-risk Chinese adult patients

INTRODUCTION

Many scales are designed to screen for obstructive sleep apnoea-hypopnoea syndrome (OSAHS); however, there is a lack of an efficiently and easily diagnostic tool, especially for Chinese. Therefore, we conduct a cross-sectional study in China to develop and validate an efficient and simple clinical diagnostic model to help screen patients at risk of OSAHS.

METHODS

This study based on 782 high-risk patients (aged >18 years) admitted to the Sleep Medicine department of the Sixth Affiliated Hospital, Sun Yat-sen University from 2015 to 2021. Totally 34 potential predictors were evaluated. We divided all patients into training and validation dataset to develop diagnostic model. The univariable and multivariable logistic regression model were used to build model and nomogram was finally built.

RESULTS

Among 602 high-risk patients with median age of 46 (37, 56) years, 23.26% were women. After selecting using the univariate logistic model, 15 factors were identified. We further used the stepwise method to build the final model with five factors: age, BMI, total bilirubin levels, high Berlin score, and symptom of morning dry mouth or mouth breathing. The AUC was 0.780 (0.711, 0.848), with sensitivity of 0.848 (0.811, 0.885), specificity of 0.629 (0.509, 0.749), accuracy of 0.816 (0.779, 0.853). The discrimination ability had been verified in the validation dataset. Finally, we established a nomogram model base on the above final model.

CONCLUSION

We developed and validated a predictive model with five easily acquire factors to diagnose OSAHS patient in high-risk population with well discriminant ability. Accordingly, we finally build the nomogram model.

Analysis of the Ischemia-Modified Albumin as a Potential Biomarker for Cardiovascular Damage in Obstructive Sleep Apnea Patients with Acute Coronary Syndrome

Obstructive sleep apnea (OSA) has been identified as a cardiovascular (CV) risk factor. The potential of OSA promoting the synthesis of CV biomarkers in acute coronary syndrome (ACS) is unknown. Ischemia-modified albumin (IMA) has been identified as a specific CV biomarker. The aim of this study was to evaluate the role of IMA as a potential biomarker for determining the impact of OSA in ACS patients. A total of 925 patients (15.5% women, age: 59 years, body mass index: 28.8 kg/m²) from the ISAACC study (NCT01335087) were included. During hospitalization for ACS, a sleep study for OSA diagnosis was performed and blood samples extraction for IMA determination were obtained. IMA values were significantly higher in severe OSA (median (IQR), 33.7 (17.2-60.3) U/L) and moderate (32.8 (16.9-58.8) U/L) than in mild/no OSA (27.7 (11.8-48.6) U/L) (p = 0.002). IMA levels were very weakly related to apnea-hypopnea index (AHI) as well as hospital and intensive care unit stay, although they only maintained a significant relationship with days of hospital stay after adjusting for sex, age and BMI (ß = 0.410, p = 0.013). The results of the present study would suggest a potentially weaker role of OSA in the synthesis of the CV risk biomarker IMA in patients with ACS than in primary prevention.

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

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

Excessive daytime sleepiness: an emerging marker of cardiovascular risk

Excessive daytime sleepiness (EDS) is classically viewed as a consequence of insufficient sleep or a symptom of sleep disorders. Epidemiological and clinical evidence have shown that patients reporting EDS in tandem with sleep disorders (e.g., obstructive sleep apnoea) are at greater cardiovascular risk than non-sleepy patients. While this may simply be attributable to EDS being present in patients with a more severe condition, treatment of sleep disorders does not consistently alleviate EDS, indicating potential aetiological differences. Moreover, not all patients with sleep disorders report EDS, and daytime sleepiness may be present even in the absence of any identifiable sleep disorder; thus, EDS could represent an independent pathophysiology. The purpose of this review is twofold: first, to highlight evidence that EDS increases cardiovascular risk in the presence of sleep disorders such as obstructive sleep apnoea, narcolepsy and idiopathic hypersomnia and second, to propose the notion that EDS may also increase cardiovascular risk in the absence of known sleep disorders, as supported by some epidemiological and observational data. We further highlight preliminary evidence suggesting systemic inflammation, which could be attributable to dysfunction of the gut microbiome and adipose tissue, as well as deleterious epigenetic changes, may promote EDS while also increasing cardiovascular risk; however, these pathways may be reciprocal and/or circumstantial. Additionally, gaps within the literature are noted followed by directions for future research.

The translational neuroscience of sleep: A contextual framework

Sleep is entwined across many physiologic processes in the brain and periphery, thereby exerting tremendous influence on our well-being. Yet sleep exists in a social-environmental context. Contextualizing sleep health with respect to its determinants—from individual- to societal-level factors—would enable neuroscientists to more effectively translate sleep health into clinical practice. Key challenges and opportunities pertain to (i) recognizing and exploring sleep’s functional roles, (ii) clarifying causal mechanisms in relation to key outcomes, (iii) developing richer model systems, (iv) linking models to known contextual factors, and (v) leveraging advances in multisensory technology. Meeting these challenges and opportunities would help transcend disciplinary boundaries such that social-environmental considerations related to sleep would become an ever-greater presence in the clinic.