Sleep Apnea and Stroke

Could an increased risk of obstructive sleep apnoea be one of the determinants associated with disability in individuals with cardiovascular and cerebrovascular diseases?

PURPOSE

To investigate a possible association between the risk of obstructive sleep apnoea (OSA) and disability in individuals with cardiovascular or cerebrovascular diseases.

METHODS

Cross-sectional study was conducted with 373 individuals (313 with cardiovascular or cerebrovascular diseases and 60 healthy). Disability was assessed by the 12-item World Health Organization Disability Assessment Schedule (WHODAS), and the risk of OSA was assessed by STOP-BANG. Anxiety and depression symptoms, daytime sleepiness, and cognition were assessed by the Hospital Anxiety and Depression Scale (HADS), Epworth Sleepiness Scale (ESS), and Mini Mental State Examination (MMSE).

RESULTS

Greater disability was found in individuals with intermediate or high risk of OSA, considering healthy individuals (p=0.03), or individuals diagnosed with arrhythmia (p<0.01) or coronary artery disease (p=0.04). A high risk of OSA and higher WHODAS scores was significant among women as well as between OSA risk categories (p<0.01). Cognitive deficit and level of education also showed differences between OSA risk categories. Age, depression, and sleepiness were also associated with the subjects' disability (p<0.01). Gamma regression model showed higher WHODAS scores in female, in those with intermediate and high risk of OSA, and in those with depressive symptoms and cognitive deficit. Age also showed a correlation with higher WHODAS scores. The presence of all investigated cardio and cerebrovascular diseases showed an increase in the WHODAS score, implying a greater disability compared to healthy individuals.

CONCLUSION

Moderate and high risk of OSA is associated with disability, as well as gender, age, depressive symptoms, cognitive deficit, and cardiovascular diseases.

Nomogram for predicting moderate-to-severe sleep-disordered breathing in patients with acute ischaemic stroke: a retrospective cohort study

OBJECTIVES

Moderate-to-severe sleep-disordered breathing (SDB) is prevalent in patients with acute ischaemic stroke (AIS) and is associated with an increased risk of unfavourable prognosis. We aimed to develop and validate a reliable scoring system for the early screening of moderate-to-severe SDB in patients with AIS, with the objective of improving the management of those patients at risk.

STUDY DESIGN

We developed and validated a nomogram model based on univariate and multivariate logistic analyses to identify moderate-to-severe SDB in AIS patients. Moderate-to-severe SDB was defined as an apnoea-hypopnoea index (AHI) ≥15. To evaluate the effectiveness of our nomogram, we conducted a comparison with the STOP-Bang questionnaire by analysing the area under the receiver operating characteristic curve.

SETTING

Large stroke centre in northern Shanghai serving over 4000 inpatients, 100 000 outpatients and emergency visits annually.

PARTICIPANTS

We consecutively enrolled 116 patients with AIS from the Shanghai Tenth People's Hospital.

RESULTS

Five variables were independently associated with moderate-to-severe SDB in AIS patients: National Institutes of Health Stroke Scale score (OR=1.20; 95% CI 0.98 to 1.47), neck circumference (OR=1.50; 95% CI 1.16 to 1.95), presence of wake-up stroke (OR=21.91; 95% CI 3.08 to 156.05), neuron-specific enolase level (OR=1.27; 95% CI 1.05 to 1.53) and presence of brainstem infarction (OR=4.21; 95% CI 1.23 to 14.40). We developed a nomogram model comprising these five variables. The C-index was 0.872, indicated an optimal agreement between the observed and predicted SDB patients.

CONCLUSIONS

Our nomogram offers a practical approach for early detection of moderate-to-severe SDB in AIS patients. This tool enables individualised assessment and management, potentially leading to favourable outcomes.

Identification of novel proteins for sleep apnea by integrating genome-wide association data and human brain proteomes

BACKGROUND

Sleep apnea is regarded as a significant global public health issue. The relationship between sleep apnea and nervous system diseases is intricate, yet the precise mechanism remains unclear.

METHODS

In this study, we conducted a comprehensive analysis integrating the human brain proteome and transcriptome with sleep apnea genome-wide association study (GWAS), employing genome-wide association study (PWAS), transcriptome-wide association study (TWAS), Mendelian randomization (MR), and colocalization analysis to identify brain proteins associated with sleep apnea.

RESULTS

The discovery PWAS identified six genes (CNNM2, XRCC6, C3orf18, CSDC2, SQRDL, and DGUOK) whose altered protein abundances in the brain were found to be associated with sleep apnea. The independent confirmatory PWAS successfully replicated four out of these six genes (CNNM2, C3orf18, CSDC2, and SQRDL). The transcriptome level TWAS analysis further confirmed two out of the four genes (C3orf18 and CSDC2). The subsequent two-sample Mendelian randomization provided compelling causal evidence supporting the association of C3orf18, CSDC2, CNNM2, and SQRDL with sleep apnea. The co-localization analysis further supported the association between CSDC2 and sleep apnea (posterior probability of hypothesis 4 = 0.75).

CONCLUSIONS

In summary, the integration of brain proteomic and transcriptomic data provided multifaceted evidence supporting causal relationships between four specific brain proteins (CSDC2, C3orf18, CNNM2, and SQRDL) and sleep apnea. Our findings provide new insights into the molecular basis of sleep apnea in the brain, promising to advance understanding of its pathogenesis in future research.

Post-stroke sleep disturbance and recurrent cardiovascular and cerebrovascular events: A systematic review and meta-analysis

Despite improvements in survival rates, risk of recurrent events following stroke remains high. Identifying intervention targets to reduce secondary cardiovascular risk in stroke survivors is a priority. The relationship between sleep and stroke is complex: sleep disturbances are likely both a contributor to, and consequence of, stroke. The current aim was to examine the association between sleep disturbance and recurrent major acute coronary events or all-cause mortality in the post-stroke population. Thirty-two studies were identified, including 22 observational studies and 10 randomized clinical trials (RCTs). Identified studies included the following as predictors of post-stroke recurrent events: obstructive sleep apnea (OSA, n = 15 studies), treatment of OSA with positive airway pressure (PAP, n = 13 studies), sleep quality and/or insomnia (n = 3 studies), sleep duration (n = 1 study), polysomnographic sleep/sleep architecture metrics (n = 1 study), and restless legs syndrome (n = 1 study). A positive relationship of OSA and/or OSA severity with recurrent events/mortality was seen. Findings on PAP treatment for OSA were mixed. Positive findings indicating a benefit of PAP for post-stroke risk came largely from observational studies (pooled RR [95% CI] for association between PAP and recurrent cardiovascular event: 0.37 [0.17-0.79], I2 = 0%). Negative findings came largely from RCTs (RR [95% CI] for association between PAP and recurrent cardiovascular event + death: 0.70 [0.43-1.13], I2 = 30%). From the limited number of studies conducted to date, insomnia symptoms/poor sleep quality and long sleep duration were associated with increased risk. Sleep, a modifiable behavior, may be a secondary prevention target to reduce the risk of recurrent event and death following stroke. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021266558.

The prognostic role of ultrasound and magnetic resonance imaging in obstructive sleep apnoea based on lateral oropharyngeal wall obstruction

PURPOSE

This study examined the prognostic value of the lateral pharyngeal wall (LPW)-based obstruction and obstructive sleep apnoea (OSA) prediction using ultrasound (US) and MRI (magnetic resonance imaging).

METHODS

One hundred patients with and without OSA were enrolled, according to overnight polysomnography. The LPW thickness (LPWT) was measured using a Philips Ingenia 1.5 T MRI device, and US measurements were carried out at rest and during Müller's manoeuvre (MM) with a Samsung RS85 device. The obstruction was localised under drug-induced sleep endoscopy.

RESULTS

Significantly greater LPWT using MRI was observed in the OSA group compared to the control group, while US results showed a significant difference only in the case of LPWT during MM on the left side. Obese patients presented significantly higher LPWT values. A significant correlation between BMI and LPWT was observed. Men presented significantly higher LPWT MRI values and left-sided LPWT using US compared to women. LPWT and AHI parameters were significantly correlated. The severity of LPW obstruction correlated with LPWT, while the LPW collapse significantly correlated with AHI. The severity of LPW collapse differed depending on the AHI values. Using US LPWT values and anthropometric parameters, a 93% effectiveness in OSA prognostication and 89% in LPWT-based obstruction were detected. MRI detected OSA in 90% and LPW-based obstruction in 84%. US successfully detected LPW-based collapse severity in 67%.

CONCLUSION

US LPWT measurements were helpful in detecting OSA and LPWT-based obstruction. These examinations may be useful for surgical planning.

Eating habit of adding salt to foods and incident sleep apnea: a prospective cohort study

BACKGROUND

Previous studies have revealed that sodium-restricted diet intervention significantly decreased apnea frequency among patients with sleep apnea. However, the longitudinal association between the habit of adding salt to foods and sleep apnea in general populations is uncertain.

METHODS

The UK Biobank cohort study includes more than 500,000 participants aged 40 to 69 across the United Kingdom from 2006 to 2010. The frequency of adding salt to foods was collected through a touch screen questionnaire. Incident sleep apnea was ascertained by hospital inpatient records, death registries, primary care, and self-reported diagnosis. The association between the habit of adding salt to foods and incident sleep apnea was estimated using Cox proportional hazard regression models.

RESULTS

Among the 488,196 participants (mean age 56.5 years; 55.0% female) in this study. During a median follow-up of 12.3 years, 6394 sleep apnea events occurred. Compared to participants who never/rarely added salt to foods, those who sometimes, usually, and always added salt to foods had an 11% (hazard ratio [HR] 1.11, 95% confidence interval [CI]: 1.04 to 1.17), 15% (HR 1.15, 95% CI: 1.07 to 1.24), and 24% (HR 1.24, 95% CI: 1.12 to 1.37) higher risk for incident sleep apnea, respectively.

CONCLUSIONS

In this large prospective study, the habit of adding salt to foods was associated with a higher risk of incident sleep apnea. The findings support the benefits of a salt reduction program in preventing sleep apnea.

Continuous positive pressure therapy usage and incident stroke in patients with obstructive sleep apnea: A nationwide population-based cohort study

INTRODUCTION

Continuous positive airway pressure (CPAP) is the main treatment for obstructive sleep apnea (OSA). To date, the link between CPAP usage and incident stroke has been inconsistent.

OBJECTIVE

This nationwide population study is designed to examine the effect of CPAP on stroke incidence in OSA patients.

METHODS

Using Taiwan's National Health Insurance Research Database (NHIRD), this study collected data from 4275 OSA patients diagnosed between 2000 and 2011 and divided them into two groups according to whether they received CPAP treatment. After matching baseline demographics and comorbidities, both cohorts contained 959 OSA patients and were followed to a newly diagnosed stroke or until the end of 2013. Cox regression analysis was performed to examine the incidence of stroke between patients with OSA receiving CPAP or no CPAP treatment.

RESULTS

CPAP treatment for OSA patients predicted a lower incidence rate (3.41 vs 5.43 per 1000 person-years) and tended to protect against the development of stroke (hazard ratio (HR): 0.68, 95% confidence interval (95% CI): 0.38-1.23) compared to those without CPAP treatment, but the estimate was not statistically significant. Similar results were also observed by dividing stroke into ischemic (2.65 vs 4.30 per 1000 person-years; HR: 0.67, 95% CI: 0.35-1.31) or hemorrhagic origin (0.76 vs 1.12 per 1000 person-years; HR: 0.67, 95% CI: 0.19-2.40).

CONCLUSIONS

It is possible that treatment with CPAP might be beneficial for protection against stroke, but this conclusion should be interpreted with caution. Future studies with satisfactory CPAP quality and duration are needed to validate this observation.

Role of rhinomanometry in the prediction of therapeutic positive airway pressure for obstructive sleep apnea

Background

This study was conducted to evaluate the relationship between nasal resistance in different posture and optimal positive airway pressure (PAP) level. Other potential factors were also assessed for possible influence on PAP pressure.

Methods

Forty- three patients diagnosed with obstructive sleep apnea (OSA) were prospectively recruited in this study. Nasal resistance was assessed by active anterior rhinomanometry in a seated position and then in a supine position at pressures of 75, 150, and 300 pascal. The factors correlating with PAP pressure were analyzed, including nasal resistance and patients’ clinical data.

Results

Univariate analysis revealed that PAP pressure was correlated to nasal resistance in the supine position at 75 and 150 pascal (SupineNR75 and SupineNR150) (P = 0.019 and P = 0.004 in Spearman’s correlation coefficient analysis), but not correlated to nasal resistance in the seated position at different pressures or in the supine position at 300 pascal. The multiple linear regression analysis revealed that both SupineNR150 and body mass index (BMI) significantly predicted PAP pressure (β = 0.308, p = 0.044; β = 0.727, p = 0.006). The final PAP pressure predictive model was:

PAP pressure = 0.29 BMI + 2.65 SupineNR150 + 2.11.

Conclusions

Nasal resistance in the supine position measured at 150 pascal may provide valuable information regarding optimal PAP pressure. Rhinomanometry should be included in the treatment algorithm of OSA patients when PAP therapy is considered.

Sleep as a Therapeutic Target in the Aging Brain

Sleep is a behavioral phenomenon conserved among mammals and some invertebrates, yet the biological functions of sleep are still being elucidated. In humans, sleep time becomes shorter, more fragmented, and of poorer quality with advancing age. Epidemiologically, the development of age-related neurodegenerative diseases such as Alzheimer's and Parkinson's disease is associated with pronounced sleep disruption, whereas emerging mechanistic studies suggest that sleep disruption may be causally linked to neurodegenerative pathology, suggesting that sleep may represent a key therapeutic target in the prevention of these conditions. In this review, we discuss the physiology of sleep, the pathophysiology of neurodegenerative disease, and the current literature supporting the relationship between sleep, aging, and neurodegenerative disease.

Oximetry as an Accurate Tool for Identifying Moderate to Severe Sleep Apnea in Patients With Acute Stroke

STUDY OBJECTIVES

Sleep-disordered breathing (SDB) is highly prevalent in patients with acute stroke. SDB is often underdiagnosed and associated with neurological deterioration and stroke recurrence. Polysomnography or home sleep apnea testing (HSAT) is typically used as the diagnostic modality; however, it may not be feasible to use regularly in patients with acute stroke. We investigated the predictive performance of pulse oximetry, a simpler alternative, to identify SDB.

METHODS

The records of 254 patients, who were admitted to Boston Medical Center for acute stroke and underwent HSAT, were retrospectively reviewed. Oxygen desaturation index (ODI) from pulse oximetry channel were compared to respiratory event index (REI) obtained from HSAT devices. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ODI were calculated, and different ODI cutoff values to predict SDB were proposed.

RESULTS

ODI had a strong correlation (r = .902) and agreement with REI. ODI was accurate in predicting SDB at different REI thresholds (REI ≥ 5, REI ≥ 15, and REI ≥ 30 events/h) with the area under the curve (AUC) of .965, .974, and .951, respectively. An ODI ≥ 5 events/h rules in the presence of SDB (specificity 91.7%, PPV 96.3%). An ODI ≥ 15 events/h rules in moderate to severe SDB (specificity 96.4%, PPV 95%) and an ODI < 5 events/h rules out moderate to severe SDB (sensitivity 100%, NPV 100%).

CONCLUSIONS

Nocturnal pulse oximetry has a high diagnostic accuracy in predicting moderate to severe SDB in patients with acute stroke. Oximetry can be a simple modality to rapidly recognize patients with more severe SDB and facilitate the referral to the confirmation sleep study.

Pathway for the Management of Sleep Apnea in the Cardiac Patient

Sleep-disordered breathing is a highly prevalent medical condition, which if undiagnosed leads to increased morbidity and mortality, particularly related to increased incidence of cardiovascular events. It is therefore imperative that we identify patient population at high risk for sleep apnea and refer them to the appropriate therapy as early as possible. Up-to-date there is no management guideline specifically geared towards cardiac patients. Thus, we propose a (SAP) Sleep Apnea Pathway to correctly identify and triage these patients to the appropriate therapy.

Daytime sleepiness is associated with hyperhomocysteinemia in rural area of China: A cross-sectional study

OBJECTIVE

To ascertain whether sleep abnormalities including daytime sleepiness, snoring, apnea, sleep disruption and sleep duration abnormity are significantly associated with hyperhomocysteinemia (Hhcy).

METHODS

A total of 5992 participants were involved in the cross-sectional study. Sleep abnormalities were evaluated by a structured questionnaire. Hhcy was defined as plasma levels of homocysteine ≥15μm/L.

RESULTS

After adjustment for age, gender, education, current smoking status and current drinking status, daytime sleepiness (OR, 1.597; 95%CI, 1.210-2.110, P=0.001), sleep duration <6h (OR, 1.273; 95%CI, 1.063-1.524, P=0.009) and sleep duration >8h (OR, 1.205; 95%CI, 1.065-1.364, P=0.003) were significantly associated with Hhcy. While snoring (OR, 1.065; 95%CI, 0.950-1.195, P=0.279), apnea (OR, 1.170; 95%CI, 0.924-1.482, P=0.193), and sleep disruption (OR, 1.065; 95%CI, 0.852-1.331, P=0.580) were not. After further adjustment for body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, total cholesterol, physical activity, diabetes, coronary heart disease, stroke, depression, glomerular filtration rate, hypertension and hyperuricemia, still the increased OR could be found in the daytime sleepiness group (OR, 1.569; 95%CI, 1.145-2.150, P=0.005). However, sleep duration <6h (OR, 1.067; 95%CI, 0.788-1.445, P=0.676) and sleep duration >8h groups (OR, 1.080; 95%CI, 0.883-1.320, P=0.453) were no longer significantly associated with Hhcy.

CONCLUSIONS

Daytime sleepiness, but not sleep duration abnormity, snoring, apnea and sleep disruption was an independent risk factor for Hhcy.

Obstructive sleep apnea and stroke: links to health disparities

Obstructive sleep apnea (OSA) is a novel cardiovascular and cerebrovascular risk factor that presents unique opportunities to understand and reduce seemingly intractable stroke disparity among non-Hispanic blacks and Hispanic/Latinos. Individuals from these 2 groups have up to a 2-fold risk of stroke and greater burden of OSA. Obstructive sleep apnea directly and indirectly increases risk of stroke through a variety of autonomic, chemical, and inflammatory mechanisms and vascular risk factors such as hypertension, obesity, and diabetes mellitus. Untreated OSA exacerbates poststroke prognosis, as it may also influence rehabilitation efforts and functional outcomes such as cognitive function after a stroke. Conversely, treatment of OSA may reduce the risk of stroke and may yield better poststroke prognosis. Unfortunately, in racial/ethnic minority groups, there are limited awareness, knowledge, and screening opportunities for OSA. Increasing awareness and improving screening strategies for OSA in minorities may alleviate stroke risk burden and improve stroke outcomes in these populations. This review article is intended to highlight the epidemiology, clinical characteristics, pathophysiology, diagnosis, and treatment of OSA in relation to stroke risk, with an emphasis on race-ethnic disparities.