Stroke and Obstructive Sleep Apnea: A Review

Obstructive sleep apnea and genotype rs6843082 as a risk factor for cerebrovascular accident

NO previous studies have examined the simultaneous effects of obstructive sleep apnea (OSA), hypertension, and the SNP rs68430822 on stroke. We aimed to explore whether these elements together, play a role as risk factors for stroke. Data was obtained from the Taiwan Biobank and the National Health Insurance database. We used logistic regression analysis to investigate the effect of OSA and hypertension as a risk factor for stroke in different genotypes. We found that OSA and hypertension was associated with stroke in those with the rs6843082 genotype. People with OSA and hypertension together with the rs6843082 genotype (GA + AA) showed a statistically significant difference as a risk for stroke (OR,2.57; 95% CI,1.53 to 4.33). However, there was no statistically significant difference in those people with OSA but without hypertension (OR, 0.53; 95% CI,0.13 to 2.25). After further stratification by combination of OSA and hypertension, those with genotype rs6843082 (GG) had higher risk odds than those with OSA and those with hypertension alone (OR,5.46, 95% CI,3.46 to 8.60). Individuals with genotype rs6843082(GA + AA), OSA and hypertension together had the highest risk for stroke (OR,6.25, 95% CI,3.63 to 10.76) and those with OSA and no hypertension (OR,0.57, 95% CI,0.14 to 2.36) had no significant risk. Our findings showed that people with genotype rs6843082 (GG), with or without hypertension had OSA as a risk factor for stroke. For individuals with the genotype rs6843082 (GA + AA), those with hypertension, OSA is a risk factor for stroke, and for those without hypertension, OSA is not associated with stroke.

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.

The Emergence of Inpatient Sleep Medicine: Screening for Sleep Disordered Breathing to Reduce the Burden of Cardiovascular Disease

Purpose of Review

Treatment of obstructive sleep apnea (OSA) has historically been centered on outpatients given sleep testing is performed on an outpatient basis. Much of this practice originates from insurers only covering sleep testing on an outpatient basis. Over the last decade, there have been innovations made in the portability of sleep monitors which have allowed sleep testing on inpatients to be facilitated. There is also emerging data that inpatient sleep testing may reduce readmissions and healthcare costs in certain cardiovascular conditions. Accordingly, this review aims to provide comprehensive coverage of recent advances in the practice of inpatient sleep medicine and its effect on reducing the burden of cardiovascular disease.

Recent Findings

Chief cardiovascular diseases that intersect with OSA in inpatients are stroke, atrial fibrillation, and heart failure. There is data from the National Inpatient Sample comparing arrhythmia burdens in patients with OSA and HFpEF showing that OSA patients have higher mortality rates, hospital durations, and medical costs. Also, OSA is associated with higher burdens of arrhythmia. It is currently unknown whether treatment of inpatients with PAP therapy lowers the occurrence of arrhythmias. Recent data suggests that costs for heart failure patients with OSA that are readmitted are higher than those for heart failure patients without OSA. A recent analysis of patients with HFpEF (heart failure with preserved ejection fraction) and OSA showed that the PAP adherent patients had fewer healthcare related costs, lower readmission rates, and fewer emergency room visits than those that were nonadherent. In broader terms, rapid initiation of PAP therapy in a large administration database query of 23 million Medicare patients appears to reduce annual healthcare costs and reduce readmissions although further study is required.

Summary

OSA is globally underdiagnosed, with an estimated one billion individuals affected. OSA's pathogenesis involves a combination of risk factors, such as obesity, age, and increased neck circumference that contribute to fragmented sleep patterns and in turn, numerous cardiovascular comorbidities, such as stroke, atrial fibrillation, and coronary artery disease. Recently, inpatient sleep medicine programs have emerged as a promising avenue for improving diagnosis, patient safety, and potentially reducing readmissions. Integrating inpatient sleep medicine into healthcare systems to address the significant health and economic burden associated with undiagnosed OSA. Improved coverage of inpatient sleep testing and services will be a key driver of addressing inpatient gaps in sleep medicine care. The current research findings provide a bedrock from which further investigations may proceed in a prospective and randomized, controlled fashion to further clarify the effects of treatment of OSA on cardiovascular outcomes of inpatients.

Sleep Disorders in Patients with Neurologic Disease

OBJECTIVE

This article provides an overview of the growing body of evidence showing bidirectional relationships between sleep and various neurologic disorders.

LATEST DEVELOPMENTS

Mounting evidence demonstrates that disrupted sleep can negatively impact various neurologic disease processes, including stroke, multiple sclerosis, epilepsy, neuromuscular disorders including amyotrophic lateral sclerosis, and headache syndromes. Abnormal sleep can also be a precursor to Alzheimer disease and neurodegenerative disease states such as Parkinson disease and dementia with Lewy bodies. Interventions to improve sleep and treat obstructive sleep apnea may play a vital role in preventing neurologic disease development and progression.

ESSENTIAL POINTS

Sleep disorders are common among patients with neurologic disorders. To provide comprehensive care to patients with neurologic conditions, neurologists must ask patients about sleep issues that may warrant further diagnostic testing, treatment, and sleep medicine referral when indicated.

Body Mass Index Measured Repeatedly over 42 Years as a Risk Factor for Ischemic Stroke: The HUNT Study

BACKGROUND

Higher BMI in middle age is associated with ischemic stroke, but little is known about BMI over adulthood, and the risk for ischemic stroke as most studies relied on a single measurement of BMI.

METHODS

BMI was measured four times over a period of 42 years. We calculated average BMI values and group-based trajectory models and related these to the prospective risk of ischemic stroke after the last examination in Cox models with a follow-up time of 12 years.

RESULTS

A total of 14,139 participants, with a mean age of 65.2 years and 55.4% women, had information on BMI from all four examinations, and we observed 856 ischemic strokes. People with overweight and obesity over adulthood had a higher risk for ischemic stroke with a multivariable-adjusted hazard ratio of 1.29 (95% CI 1.11-1.48) and 1.27 (95% CI 0.96-1.67), respectively, when compared to normal weight participants. Excess weight tended to have stronger effects earlier than later in life. A trajectory of developing obesity throughout life was associated with higher risk than other trajectories.

CONCLUSIONS

High average BMI, especially at an early age, is a risk factor for ischemic stroke. Early weight control and long-term weight reduction for those with high BMI may decrease the later occurrence of ischemic stroke.

Post-Operative Patients’ Satisfaction and Quality of Life Assessment in Adult Patients with Obstructive Sleep Apnea Syndrome (OSAS)

Background: The treatment for severe OSAS includes maxillomandibular advancement surgical option in selected cases. The aim of this study was to evaluate the post-operative impact of bimaxillary surgery on satisfaction and consequently the quality of life of these patients. Methods: This study included 18 patients with severe OSAS who received maxillomandibular advancement surgery. Patients were divided into Group A (operated by CAD/CAM) and Group B (conventional surgery). The impact of bimaxillary surgery on satisfaction and quality of life of these patients was evaluated by utilizing post-operative life quality and Rustemeyer’s patient-satisfaction-based survey. Results: A total of 18 adult OSAS patients (Group A: 11 patients, Group B: 7 patients) with a mean age of 44.39 years (SD ± 9.43) were included. Mean follow-up period was 32.64 months (SD ± 21.91). No intra-operative complications were seen in any patients. Post-operative complication was seen in one patient and the mandible did not integrate. According to the results, overall post-operative satisfaction score was 79.72% (SD ± 9.96). There was no significant difference among those in Group A and Group B. Conclusion: Maxillomandibular advancement surgery seems to be beneficial in terms of patients’ satisfaction in severe adult OSAS patients and can be considered as a valuable option in selected cases.

Dynamic Prevalence of Sleep Disorders Following Stroke or Transient Ischemic Attack: Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

The exact prevalence of sleep disorders following stroke or transient ischemic attack (TIA) remains unclear. We aimed to determine the prevalence of sleep-disordered breathing, insomnia, periodic leg movement during sleep, and restless leg syndrome following stroke or TIA in acute, subacute, and chronic phases and examine the moderating effects of patient characteristics (eg, age) and methodological features (eg, study quality) on the prevalence.

METHODS

We performed a systematic review and meta-analysis. Embase and PubMed were searched from inception to December 18, 2019. We included 64 047 adults in 169 studies (prospective, retrospective, case-control, and cross-sectional study designs) reporting the prevalence of sleep disorders following stroke or TIA.

RESULTS

In the acute phase, the overall prevalence of mild, moderate, and severe sleep-disordered breathing was 66.8%, 50.3%, and 31.6% (95% CIs, 63.8-69.7, 41.9-58.7, and 24.9-39.1). In the subacute phase, the prevalence of mild, moderate, and severe sleep-disordered breathing was 65.5%, 44.3%, and 36.1% (95% CIs, 58.9-71.5, 36.1-52.8, and 22.2-52.8). In the chronic phase, the summary prevalence of mild, moderate, and severe sleep-disordered breathing was 66.2%, 33.1%, and 25.1% (95% CIs, 58.6-73.1, 24.8-42.6, and 10.9-47.6). The prevalence rates of insomnia in the acute, subacute, and chronic phases were 40.7%, 42.6%, and 35.9% (95% CIs, 31.8-50.3, 31.7-54.1, and 28.6-44.0). The pooled prevalence of periodic leg movement during sleep in the acute, subacute, and chronic phases was 32.0%, 27.3%, and 48.2% (95% CIs, 7.4-73.5, 11.6-51.7, and 33.1-63.5). The summary prevalence of restless leg syndrome in the acute and chronic phases was 10.4% and 13.7% (95 CIs, 6.4-16.4 and 2.3-51.8). Age, sex, comorbidities, smoking history, and study region had significant moderating effects on the prevalence of sleep disorders.

CONCLUSIONS

Sleep disorders following stroke or TIA are highly prevalent over time. Our findings indicate the importance of early screening and treating sleep disorders following stroke or TIA.

Acute inorganic nitrate supplementation and the hypoxic ventilatory response in patients with obstructive sleep apnea

Patients with obstructive sleep apnea (OSA) have increased cardiovascular disease risk largely attributable to hypertension. Heightened peripheral chemoreflex sensitivity (i.e., exaggerated responsiveness to hypoxia) facilitates hypertension in these patients. Nitric oxide blunts the peripheral chemoreflex, and patients with OSA have reduced nitric oxide bioavailability. We therefore investigated the dose-dependent effects of acute inorganic nitrate supplementation (beetroot juice), an exogenous nitric oxide source, on blood pressure and cardiopulmonary responses to hypoxia in patients with OSA using a randomized, double-blind, placebo-controlled crossover design. Fourteen patients with OSA (53 ± 10 yr, 29.2 ± 5.8 kg/m², apnea-hypopnea index = 17.8 ± 8.1, 43%F) completed three visits. Resting brachial blood pressure and cardiopulmonary responses to inspiratory hypoxia were measured before, and 2 h after, acute inorganic nitrate supplementation [∼0.10 mmol (placebo), 4.03 mmol (low dose), and 8.06 mmol (high dose)]. Placebo increased neither plasma [nitrate] (30 ± 52 to 52 ± 23 μM, P = 0.26) nor [nitrite] (266 ± 153 to 277 ± 164 nM, P = 0.21); however, both increased following low (29 ± 17 to 175 ± 42 μM, 220 ± 137 to 514 ± 352 nM) and high doses (26 ± 11 to 292 ± 90 μM, 248 ± 155 to 738 ± 427 nM, respectively, P < 0.01 for all). Following placebo, systolic blood pressure increased (120 ± 9 to 128 ± 10 mmHg, P < 0.05), whereas no changes were observed following low (121 ± 11 to 123 ± 8 mmHg, P = 0.19) or high doses (124 ± 13 to 124 ± 9 mmHg, P = 0.96). The peak ventilatory response to hypoxia increased following placebo (3.1 ± 1.2 to 4.4 ± 2.6 L/min, P < 0.01) but not low (4.4 ± 2.4 to 5.4 ± 3.4 L/min, P = 0.11) or high doses (4.3 ± 2.3 to 4.8 ± 2.7 L/min, P = 0.42). Inorganic nitrate did not change the heart rate responses to hypoxia (beverage-by-time P = 0.64). Acute inorganic nitrate supplementation appears to blunt an early-morning rise in systolic blood pressure potentially through suppression of peripheral chemoreflex sensitivity in patients with OSA.NEW & NOTEWORTHY The present study is the first to examine the acute effects of inorganic nitrate supplementation on resting blood pressure and cardiopulmonary responses to hypoxia (e.g., peripheral chemoreflex sensitivity) in patients with obstructive sleep apnea (OSA). Our data indicate inorganic nitrate supplementation attenuates an early-morning rise in systolic blood pressure potentially attributable to blunted peripheral chemoreflex sensitivity. These data show proof-of-concept that inorganic nitrate supplementation could reduce the risk of cardiovascular disease in patients with OSA.

Obstructive Sleep Apnea Risk and Stroke among Blacks with Metabolic Syndrome: Results from Metabolic Syndrome Outcome (MetSO) Registry

INTRODUCTION

The American Stroke Association estimates that stroke is the fifth leading cause of death in the United States. According to the Center for Disease Control and Prevention someone in the United States has a stoke every 40 seconds, affecting more than 795,000 people of which 140,000 result in death [1]. Emerging evidence suggests that obstructive sleep apnea (OSA) is a strong risk factor for stroke. This study using The Metabolic Syndrome Outcome (MetSO) registry explored whether blacks at risk for obstructive sleep apnea (OSA) are at greater risk for a stroke.

METHOD

The present study utilized data from the MetSO study, an NIH-funded cohort study of blacks with metabolic syndrome (MetS). Patients were diagnosed with MetS using standard criteria articulated in the joint interim statement for harmonizing the MetS. The study assessed OSA risk using the Apnea Risk Evaluation System (ARES); defining high risk as a total ARES score ≥6. Data was coded and analyzed by an experienced statistician using SPSS 20.0.

RESULTS

A total of 1035 participants were screened for MetS in the MetSO registry. During the data collection period 875 participants were enrolled during the time of analysis. The average age of the sample was 62±14 years (range: 20-97); 71% were female, and all were of black race/ethnicity. Seventy-one percent reported finishing high school, and 43% reported annual income <10K. Descriptive analyses showed 93% of the participants were diagnosed with hypertension; 61%, diabetes; 72%, dyslipidemia; 90% were overweight/obese; 33% had a history of heart disease and 10% had a stroke history. Using the ARES screener, we estimated that 48% were at high risk for OSA. Logistic regression analysis, adjusting for age and gender, showed that patients at high risk for OSA had a nearly three-fold increase in the odds of having a stroke (OR = 2.79, 95% CI: 1.64-4.73).

CONCLUSION

In the MetSO registry, a cohort of blacks with MetS, the prevalence of stroke is greater than in the general US population. Blacks at risk for OSA are particularly vulnerable to experiencing a stroke.

Increased platelet activation in sleep apnea subjects with intermittent hypoxemia

PURPOSE

Obstructive sleep apnea (OSA) is independently associated with increased risk for stroke and other cardiovascular diseases. Since activated platelets play an important role in cardiovascular disease, the objective of this study was to determine whether platelet reactivity was altered in OSA subjects with intermittent nocturnal hypoxemia.

METHODS

Thirty-one subjects, without hypertension or cardiovascular disease and not taking medication, participated in the study. Subjects were stratified based on OSA-related oxygen desaturation index (ODI) recorded during overnight polysomnography. Platelet reactivity to a broad panel of agonists (collagen, thrombin, protease-activated receptor1 hexapeptide, epinephrine, ADP) was measured by monitoring platelet aggregation and ATP secretion. Expression of platelet activation markers CD154 (CD40L) and CD62P (P-selectin) and platelet-monocyte aggregates (PMA) was quantified by flow cytometry.

RESULTS

Epinephrine-induced platelet aggregation was substantially decreased in OSA subjects with significant intermittent hypoxemia (ODI ≥ 15) compared with subjects with milder hypoxemia levels (ODI < 15) (area under curve, p = 0.01). In addition, OSA subjects with ODI ≥ 15 exhibited decreased thrombin-induced platelet aggregation (p = 0.02) and CD40L platelet surface expression (p = 0.05). Platelet responses to the other agonists, CD62P platelet surface expression, and PMA levels were not significantly different between groups. Reduction in platelet responses to epinephrine and thrombin, and decreased CD40L surface marker expression in significant hypoxemic OSA individuals, is consistent with their platelets being in an activated state.

CONCLUSIONS

Increased platelet activation was present in otherwise healthy subjects with intermittent nocturnal hypoxemia due to underlying OSA. This prothrombotic milieu in the vasculature is likely a key contributing factor toward development of thrombosis and cardiovascular disease.

TRIAL REGISTRATION

NCT00859950.

Is Maxillomandibular Advancement Associated With Comorbidity Reduction in Patients With Obstructive Sleep Apnea?

PURPOSE

This study investigated whether patients with documented obstructive sleep apnea (OSA) who have a decrease in apnea-hypopnea index (AHI) score and self-reported symptoms after maxillomandibular advancement (MMA) with genial tubercle advancement (GTA) also have a change in their medical comorbidity profile a minimum of 2 years postoperatively. Changes in the quantity of medical diagnoses, quantity of prescription medications, and average weight and body mass index (BMI) were assessed.

PATIENTS AND METHODS

This is a retrospective cohort study of patients with a diagnosis of OSA (AHI score >5 on polysomnogram [PSG]) treated at the Massachusetts General Hospital (Boston, MA) with MMA and GTA from 2001 through 2015. Patients were identified through the oral and maxillofacial surgery patient data registry. Inclusion criteria were the availability of complete clinical records and requisite follow-up time. The primary predictor variable was operative status (preoperative or postoperative). The primary outcome variables were comorbidities reported to be associated with OSA and identified in the authors' previous study (J Oral Maxillofac Surg 76:1999.e1, 2018). Two-tailed paired t tests were used for continuous variables and χ² or Fisher exact tests were used for categorical variables.

RESULTS

Forty-six patients (39 men, 7 women) met the inclusion criteria. Average weight (206.7 ± 42.4 lb preoperatively; 213.8 ± 41.7 lb postoperatively; P = .014) and average BMI (30.0 ± 5.7 kg/m² preoperatively; 30.9 ± 5.3 kg/m² postoperatively; P = .041) significantly increased in patients postoperatively. No meaningful changes in the number of medical diagnoses or number of prescription medications were noted. Stratification of patients by BMI showed significant increases in weight (188.6 ± 21.5 lb preoperatively; 200.1 ± 27.9 lb postoperatively; P = .0085) and BMI (27.1 ± 1.44 kg/m² preoperatively; 28.9 ± 3.52 kg/m² postoperatively; P = .013) only in "overweight" patients. No other parameters were found to be relevant.

CONCLUSIONS

Subjective improvement in OSA symptoms was reported by all patients and objective PSG improvement was reported for 71% of those evaluated. However, no relevant changes in comorbidity profile were found, suggesting that the medical conditions commonly observed with OSA are likely of multifocal etiology.

Sleep Architecture in Patients With Primary Snoring and Obstructive Sleep Apnea

Introduction:

This study aimed to investigate sleep architecture in patients with primary snoring and obstructive sleep apnea.

Methods:

In this study, we analyzed polysomnographic data of 391 clients who referred to Sleep Disorders Research Center (SDRS). These people were classified into three groups based on their Apnea-Hypopnea Index (AHI) and snoring; control, Primary Snoring (PS), and Obstructive Sleep Apnea (OSA) group. Sleep architecture variables were then assessed in all groups.

Results:

The results of this study indicated a decrease in deep sleep or Slow Waves Sleep (SWS) and increase in light sleep or stage 1 of non-REM sleep (N1) in OSA patients compared with the control and PS groups. After controlling the effects of confounding factors, i.e. age and Body Mass Index (BMI) (which was performed through multiple regression analysis) significant differences were observed among the three groups with regard to N1. However, with regard to SWS, after controlling confounding variables (age and BMI), no significant difference was found among the groups.

Conclusion:

The results indicated that OSA, regardless of age and BMI, may increase light (N1) sleep possibly via a decline in blood oxygen saturation (SpO₂ ). Such increase in N1 may be responsible for brain arousal. In addition, by controlling confounding factors (age and BMI), OSA did not affect SWS in OSA patients. However, further research is necessary to determine sleep architecture in more detail in the patients with OSA.

Does the Medical Comorbidity Profile of Obstructive Sleep Apnea Patients Treated With Maxillomandibular Advancement Differ From That of Obstructive Sleep Apnea Patients Managed Nonsurgically?

PURPOSE

Obstructive sleep apnea (OSA) patients with retrognathia and measurable anatomic airway determinants may represent a subset of OSA patients and have distinct comorbidity profiles. Our aim was to compare the medical comorbidities of OSA patients managed surgically with maxillomandibular advancement with those of nonsurgical patients.

PATIENTS AND METHODS

In this cross-sectional retrospective study, patients for both cohorts were identified through the Massachusetts General Hospital oral and maxillofacial surgery data registry and the Massachusetts General Hospital Research Patient Data Registry. The inclusion criteria consisted of clinical records documenting body mass index (BMI), apnea-hypopnea index, respiratory disturbance index, and/or oxygen nadir. The primary predictor variable was the treatment modality chosen: surgical (maxillomandibular advancement) or nonsurgical. Demographic information and OSA parameters were evaluated. The primary outcome variable was the number of documented comorbidities in each group. Two-sample t tests were used for continuous variables, whereas χ² or Fisher exact tests were used for categorical variables.

RESULTS

The nonsurgical cohort consisted of 71 patients (67.6% men), and the surgical cohort consisted of 51 patients (84.3% men). Comparison of descriptive characteristics showed that the nonsurgical cohort had a higher average age (49 ± 9.4 years) than the surgical cohort (41 ± 10.7 years, P < .001). In addition, a higher average BMI was present in the nonsurgical group (42.3 ± 11.9 in nonsurgical group vs 29.7 ± 5.5 in surgical group, P < .001). Polysomnogram parameters were comparable with the exception of a higher Epworth Sleepiness Scale score in the surgical cohort (15.5 ± 5.30 in surgical group vs 9.90 ± 6.80 in nonsurgical group, P = .005). The nonsurgical cohort had a higher total number of comorbidities (7 ± 4 in nonsurgical group vs 4 ± 3 in surgical group, P < .001). Hypertension, cardiovascular disease, hyperlipidemia, pulmonary hypertension, obstructive pulmonary disease, and type 2 diabetes mellitus had higher prevalences within the nonsurgical group.

CONCLUSIONS

The results of this study suggest that nonsurgically managed OSA patients tend to have more complex medical comorbidity profiles than those managed surgically. Obesity (BMI >30) was more prevalent in the nonsurgical cohort, which may be contributory. The additive contribution of OSA needs to be further elucidated.

Neurologic Diseases and Sleep

Sleep disorders and neurologic illness are common and burdensome in their own right; when combined, they can have tremendous negative impact at an individual level as well as societally. The socioeconomic burden of sleep disorders and neurologic illness can be identified, but the real cost of these conditions lies far beyond the financial realm. There is an urgent need for comprehensive care and support systems to help with the burden of disease. Further research in improving patient outcomes in those who suffer with these conditions will help patients and their families, and society in general.

Assessment of left atrial appendage function during sinus rhythm in patients with obstructive sleep apnea

Objective:

Obstructive sleep apnea (OSA) is associated with thromboembolic events. Compromised left atrial appendage (LAA) function due to left ventricular (LV) performance abnormality, often present in patients with OSA, may play an important role. The purpose of this study is to evaluate LV and LAA mechanical functions during sinus rhythm (SR) in patients with OSA.

Methods:

LV and LAA functions were assessed in 43 OSA patients and compared with that of 20 control patients in SR. Tissue Doppler velocities of the LAA apex and emptying velocities (EV) of LAA were obtained on parasternal short-axis view.

Results:

The baseline clinical characteristics were similar except for AHI (apnea-hypopnea index), minimal SaO₂, mean SaO₂, hypertension, and body-surface area. Most of the LV echocardiographic parameters significantly deteriorated in OSA patients in comparison with those in the control group. LAA EV, LAA systolic relaxation velocity (S_M), LAA early-diastolic velocity (E_M), LAA contraction velocity (A_M), left atrial (LA) minimum volume index, LA ejection fraction, LA conduit volume index, and LA reservoir volume index were lower in OSA patients compared with those in the control group (p<0.05). LAA A_M was negatively correlated with AHI and the ratio of peak early diastolic flow velocity (E) to early-diastolic (E’) and positively correlated with LA conduit volume (p<0.05). Multiple predictors for LAA A_M were AHI, presence of diastolic dysfunction, and E/E’ values (p<0.05).

Conclusion:

LAA mechanical function is significantly depressed in patients with OSA and SR. LAA dysfunction may predispose these patients to thromboembolic events. The evaluation of LAA mechanical function by tissue Doppler study using transthoracic echocardiography (TTE) may become an alternative for routine work-up in OSA patients.

Overweight and Obesity in Young Adulthood and the Risk of Stroke: a Meta-analysis

BACKGROUND

A systematic review assessing the association between overweight and obesity in young adulthood and stroke risk is lacking. Therefore, we conducted a meta-analysis to evaluate the association between overweight and obesity in young adulthood and stroke risk.

METHODS

We systematically searched PubMed and Embase databases for related studies of human subjects in the English language. Two investigators independently selected original studies in a 2-step process. Fixed- and random-effects models were used to calculate pooled relative risks (RRs) and 95% confidence intervals (CIs). Subgroup analyses were also performed.

RESULTS

Eight studies met the inclusion criteria. The pooled adjusted RR of stroke was 1.36 (95% CI: 1.28-1.44) for overweight in young adulthood and 1.81 (95% CI: 1.45-2.25) for obesity in young adulthood. In subgroup analyses, overweight and obesity in young adulthood increased the risk of stroke in most groups, except for the group of stroke subtype. For ischemic stroke, the adjusted RR was 1.40 (95% CI: 1.24-1.58) for overweight in young adulthood and 1.78 (95% CI: 1.003-3.16) for obesity in young adulthood, whereas adjusted RR for hemorrhagic stroke was 1.25 (95% CI: .83-1.90) for overweight in young adulthood and 1.80 (95% CI: .97-3.35) for obesity in young adulthood.

CONCLUSIONS

Overweight and obesity in young adulthood are associated with an increased risk of stroke, probably, independent of other cardiovascular risk factors. The risk effect gradually increases with increasing body weight.

Sleep Disordered Breathing and Risk of Stroke in Older Community-Dwelling Men

STUDY OBJECTIVES

Men with sleep disordered breathing (SDB) may be at increased stroke risk, due to nocturnal hypoxemia, sleep loss or fragmentation, or other mechanisms. We examined the association of SDB with risk of incident stroke in a large cohort of older men.

METHODS

Participants were 2,872 community-dwelling men (mean age 76 years) enrolled in the MrOS Sleep Study, which gathered data from 2003 to 2005 at six clinical sites in the Unites States. SDB predictors (obstructive apnea-hypopnea index, apnea-hypopnea index, central apnea index, and nocturnal hypoxemia) were measured using overnight polysomnography. Incident stroke over an average follow-up of 7.3 years was centrally adjudicated by physician review of medical records.

RESULTS

One hundred fifty-six men (5.4%) had a stroke during follow-up. After adjustment for age, clinic site, race, body mass index, and smoking status, older men with severe nocturnal hypoxemia (≥ 10% of the night with SpO2 levels below 90%) had a 1.8-fold increased risk of incident stroke compared to those without nocturnal hypoxemia (relative hazard = 1.83; 95% confidence interval 1.12-2.98; P trend = 0.02). Results were similar after further adjustment for other potential covariates and after excluding men with a history of stroke. Other indices of SDB were not associated with incident stroke.

CONCLUSIONS

Older men with severe nocturnal hypoxemia are at significantly increased risk of incident stroke. Measures of overnight oxygen saturation may better identify older men at risk for stroke than measures of apnea frequency.

Treatment of obstructive sleep apnea syndrome associated with stroke

The association between sleep-disordered breathing and stroke has been a subject of increased interest and research. Obstructive sleep apnea (OSA) is an important risk factor for stroke incidence and mortality. Moreover, OSA is a common clinical outcome after stroke, directly influencing the patient's recovery. The treatment of choice for OSA is positive airway pressure (PAP) support and the PAP appliance is considered the most recommended clinical management for the treatment of patients with cardiovascular complications. However, the implementation of PAP in stroke patients remains a challenge, considering the increased frequency of motor and language impairments associated with the cerebrovascular event. In the present study, we reviewed the main findings describing the association between stroke and OSA treatment with continuous positive airway pressure. We also discussed the types of OSA treatment, the different options and indications of PAP treatment, PAP adherence and the clinical outcomes after treatment.

Circadian sleep/wake rhythm abnormalities as a risk factor of a poststroke apathy

BACKGROUND

Poststroke apathy affects 19-55% of patients following stroke and has a negative impact on functional recovery, general health, and quality of life, as well as being a source of significant burden for caregivers.

AIMS

A major clinical issue is the delayed diagnosis of poststroke apathy, and so the aim of our study is to evaluate the relationship between early poststroke alterations of circadian rhythms of sleep/wake cycles and the occurrence of poststroke apathy.

METHODS

Forty-six patients with a recent magnetic resonance imaging confirmed stroke were included. Main exclusion criteria were a mild to severe disability impeding home discharge from the hospital and the presence of apathy or dementia before stroke. Cerebrovascular lesions were evaluated by magnetic resonance imaging. At hospital discharge, an actigraph was used to measure patient's global activity as well as parameters of circadian rhythmicity (relative amplitude, interdaily stability, intradaily variability) and sleep (sleep duration, sleep efficiency, fragmentation index) over seven-days. Apathy was assessed at hospital discharge as well as at three-months using the Apathy Inventory and the Lille Apathy Rating Scale.

RESULTS

Of the 46 patients evaluated, 10 (22%) showed apathy three-months after stroke (median Apathy Inventory = 4·5). Before inclusion, these 10 subjects did not differ significantly from other patients concerning their sleep and, at inclusion, they did not differ concerning apathy, anxiety, depression, or cognitive and functional abilities. However, actigraphy measured at discharged identified significant alterations of sleep (P < 0·005). Future poststroke apathy patients exhibited a decrease in sleep efficiency (actual sleep time expressed as a percentage of time in bed) and an increase in the fragmentation index (degree of fragmentation during the sleep period) at three-months. No association was observed between poststroke apathy and the characteristics of cerebrovascular lesions (stroke location, extent of leucoencephalopathy, number of lacunes and microbleeds).

CONCLUSION

These results indicate that early poststroke alterations of sleep/wake circadian rhythms--easily evaluated by actigraphy--are associated with a higher risk of poststroke apathy at three-months. In terms of clinical outcomes, our results provide targets for very early identification of patients at risk to develop apathy after stroke and for assessing when to start specific therapy to optimize rehabilitation efficiency.

Screening for atrial fibrillation in patients with obstructive sleep apnoea to reduce ischaemic strokes

Obstructive sleep apnoea is an independent risk factor for stroke. A number of different mechanisms have been identified which link OSA and stroke including hypertension and oxidative stress. Atrial fibrillation (AF) is likely to play a role in the development of stroke in patients with OSA. Indeed, patients with OSA have a higher incidence of AF than the general population. Given the higher constellation of cardiovascular co-morbidities seen in patients with OSA, we believe that a strategy of actively screening for the presence of AF in patients with OSA and initiating oral anticoagulation therapy when appropriate may reduce the burden of stroke in this population. This is a question that needs to be addressed in a clinical trial.

The relationship among restless legs syndrome (Willis-Ekbom Disease), hypertension, cardiovascular disease, and cerebrovascular disease

Untreated sleep disorders may contribute to secondary causes of uncontrolled hypertension, cardiovascular disease (CVD), and stroke. Restless legs syndrome, or Willis–Ekbom Disease (RLS/WED), is a common sensorimotor disorder with a circadian rhythmicity defined by an uncontrollable urge to move the legs that worsens during periods of inactivity or at rest in the evening, often resulting in sleep disruptions. Sleep disorders such as insomnia and obstructive sleep apnea (OSA) are established risk factors for increased risk of hypertension and vascular diseases. This literature review outlines the lessons learned from studies demonstrating insomnia and OSA as risk factors for hypertension and vascular diseases to support the epidemiologic and physiologic evidence suggesting a similar increase in hypertension and vascular disease risk due to RLS. Understanding the relationships between RLS and hypertension, CVD, and stroke has important implications for reducing the risks associated with these diseases.