Sleep-Disordered Breathing After Stroke

Obstructive sleep apnea and cardiovascular risk

Patients with obstructive sleep apnea (OSA) experience repetitive episodes of upper airway obstruction due to recurrent collapse during sleep. This leads to intermittent hypoxia episodes, which, through complex pathophysiological mechanisms, trigger sympathetic overactivation, endothelial dysfunction, hypercoagulation, and metabolic dysregulation. Consequently, other cardiovascular risk factors such as hypertension, metabolic syndrome, and diabetes are induced. Furthermore, this enhances target organ damage, affecting the heart, arteries, and kidneys, leading to an increased risk of cardiovascular morbidity and mortality. Among the various treatments for OSA, Continuous Positive Airway Pressure (CPAP) has been extensively studied. To date, this treatment has shown mild benefits in reducing blood pressure, particularly noticeable in patients with resistant hypertension. Furthermore, CPAP treatment appears to reduce cardiovascular events, both in primary and secondary prevention, though this benefit is limited to individuals with good compliance (CPAP use ≥4h/night). Future research perspectives in OSA seem to focus on identifying patients in whom the condition significantly influences cardiovascular risk, thus determining those who would benefit the most from treatment in the reduction of cardiovascular risk.

A Systematic Review and Meta-Analysis on the Identification of Predictors Associated With Insomnia or Sleep Disturbance in Post-stroke Patients

The aim of this study was to identify the factors associated with sleep disturbances in individuals after a stroke. To systematically identify relevant studies, an extensive search strategy was devised. We conducted comprehensive searches in major electronic databases including PubMed, Embase, PsycINFO, and Cochrane Library. The search was limited to articles published in English between January 1, 2011, and February 10, 2024. Pooled effect estimates, such as odds ratio (OR) or mean difference (MD) along with their confidence interval (CIs), were calculated using random-effects models for categorical variables and continuous variables, respectively. A total of nine studies were included in this meta-analysis. The pooled prevalence of insomnia across the included studies was determined to be 40% (95% CI = 30%-49%), with individual study prevalence ranging from 22% to 72%. A pooled analysis showed that gender demonstrated a statistically significant association with sleep disturbance, with females exhibiting a higher likelihood (OR = 1.49, 95% CI = 1.16-1.91, p = 0.002) compared to males. The National Institutes of Health Stroke Scale (NIHSS) score, a measure of stroke severity, was associated with sleep disturbance (MD = 0.86, 95% CI = 0.56-1.17, p = 0.001), indicating that patients with severe strokes may be more prone to sleep disturbances. These findings underscore the importance of comprehensive evaluation and targeted interventions to address sleep-related issues in stroke patients, particularly those with severe neurological impairment.

Positive airway pressure therapy for post-stroke sleep disordered breathing: a systematic review, meta-analysis and meta-regression

BACKGROUND

Sleep disordered breathing (SDB) is an under-recognised independent risk factor and a potential consequence of stroke. We systematically reviewed and meta-analysed the effectiveness of positive airway pressure (PAP) therapy in improving post-stroke outcomes.

METHODS

We searched CENTRAL, Embase, PubMed, CINAHL, PsycINFO, Scopus, ProQuest, Web of Science and CNKI (China National Knowledge Infrastructure) for randomised controlled trials comparing PAP therapy against a control or placebo group. We evaluated the pooled effects of PAP therapy on recurrent vascular events, neurological deficit, cognition, functional independence, daytime sleepiness and depression using random effects meta-analyses.

RESULTS

We identified 24 studies. Our meta-analyses showed that PAP therapy reduced recurrent vascular events (risk ratio 0.47, 95% CI 0.28-0.78), and showed significant beneficial effects on neurological deficit (Hedges' g= -0.79, 95% CI -1.19- -0.39), cognition (g=0.85, 95% CI 0.04-1.65), functional independence (g=0.45, 95% CI 0.01-0.88) and daytime sleepiness (g= -0.96, 95% CI -1.56- -0.37). However, there was insignificant reduction in depression (g= -0.56, 95% CI -2.15-1.02). No publication bias was detected.

CONCLUSIONS

Post-stroke patients with SDB benefited from PAP therapy. Prospective trials are needed to determine the ideal initiation period and the minimum effective therapeutic dose.

Prevalence of sleep-related breathing disorders and associated risk factors among people with dementia: A meta-analysis

OBJECTIVE

Sleep-related breathing disorders (SRBD) have shown to cause worsened cognitive impairment among people with dementia. Therefore, we conducted the first meta-analysis to estimate the prevalence of SRBD among people with dementia.

METHODS

Comprehensive searches were conducted in Embase, Ovid-MEDLINE, PubMed, PsycINFO, Scopus, Web of Science, and CINAHL. The generalized linear mixed model (GLMM) was used for the pooled prevalence analysis and heterogeneity using I² test and Cochran's Q-statistic in R-software. Study quality was assessed by Hoy's risk of bias assessment tool. Overall, 20 studies from 1282 studies were included with 1461 participants.

RESULTS

The pooled prevalence of SRBD among dementia was 59% (95%CI: 44%-73%) with 55% (95%CI: 34%-74%) for obstructive sleep apnea (OSA), 49% (95%CI: 25%-73%) for unspecified SRBD, and 11% (95%CI: 5%-21%) for central sleep apnea (CSA). Regarding dementia subtypes, the prevalence of SRBD was 89% (95%CI: 61%-97%) for Alzheimer's dementia, 56% (95%CI: 48%-63%) for Parkinson's and Idiopathic Parkinson's dementia, and 16% (95%CI: 8%-30%) for Huntington's dementia. Significant moderator variables were male, body mass index, larger waist and hip circumference, waist-hip ratio, and comorbidities including hypertension, dyslipidemia, renal disease, diabetes, heart disease, and stroke.

CONCLUSIONS

There is considerable high prevalence of SRBD among dementia people, with OSA and unspecified SRBD being fivefold higher than CSA. Regarding dementia subtypes, Parkinson's and Idiopathic Parkinson's, and Alzheimer's dementia had four to sixfold increased risk of presenting with SRBD than Huntington's dementia. Therefore, assessment and management of SRBD in Alzheimer's, and Parkinson's and Idiopathic Parkinson's dementia deserves more attention in future research.

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.

[Clinical profile of patients with obstructive sleep apnea syndrome in a cardiology hospital]

RELEVANCE

Obstructive sleep apnea syndrome (OSAS) is an important medical and social problem due to its high prevalence and impact on quality of life. The relationship between OSAS and cardiovascular pathology has been proven by many studies, which confirms the necessity for early diagnosis of OSAS and its treatment for the prevention of fatal and non-fatal events.

AIM

to study epidemiological and clinical profile of the patients referred by a cardiologist to a specialized sleep laboratory to verify the diagnosis of OSAS.

MATERIALS AND METHODS

Object of study 527 patients aged 56.912.5 years who were hospitalized to the Myasnikov Clinical Cardiology Research Institute from 20162018 and had OSAS risk factors. Initially, complaints, medical history, anthropometric data were collected. As a screening survey, questionnaires were conducted using questionnaire scales. Verification of the diagnosis of OSAS and determination of the severity was carried out by cardiorespiratory or respiratory monitoring. Subsequently, 4 groups were formed depending on the presence and severity of OSAS.

RESULTS

The prevalence of OSAS among patients in a cardiology hospital referred to a verification study was 88.6%. A comparative analysis of the groups revealed a progressive increase in the values of anthropometric indicators with increasing severity of OSAS. No differences were found between the groups by gender and daytime sleepiness on the Karolinska Sleepiness Scale. The average score on the Epworth sleepiness scale was statistically significantly lower only in the group of patients without OSAS when compared with the group with a severe degree of OSAS, and is comparable with the scores in the groups of mild and moderate degrees of OSAS. In a multivariate model of logistic regression, independent predictors of OSAS were identified as: age over 45 years, indications of loud intermittent snoring, frequent nightly urination, overweight or obesity. According to the results of assessing the incidence of various cardiovascular diseases in patients referred to the sleep laboratory, no significant differences were detected. At the same time, a significant difference was found in the frequency of obesity in patients with severe OSAS compared with other groups, as well as the frequency of type 2 diabetes mellitus or impaired glucose tolerance when compared with groups without OSAS, and with mild OSAS. In one-factor logistic regression models, it was found that the likelihood of having a severe degree of OSAS increases with increasing both comorbidity and age.

CONCLUSIONS

High prevalence of OSAS in patients of a cardiological hospital, referred to a sleep laboratory for verification study, was confirmed. Considering the data that early diagnosis and treatment of OSAS can affect the course of both nosologies, the quality of life and prognosis of these patients, it is advisable to routinely screen and verify the diagnosis of OSAS in patients with cardiovascular diseases.

Ambulatory blood pressure monitoring on admission in survivors of recent stroke entering inpatient rehabilitation

Arterial hypertension (AHT) is a major risk factor for stroke, yet blood pressure (BP) goals thereafter remain uncertain. Although additional prognostic value of 24-hour ambulant BP monitoring (ABPM) is acknowledged, its clinical impacts remain limited. We suspected that routine ABPM could identify characteristic circadian BP patterns in different brain lesion types, the knowledge of which might, in turn, be helpful in improving overall BP management in patients after stroke. In our study, we compared cardiovascular parameters derived from ABPM and traditional blood pressure measurements (TBPM) among 105 stroke survivors who entered our inpatient neuro-rehabilitation program. The mean age of mostly male (64.8%) patients was 71 ± 12 years. Ischemic strokes were predominant (75.2%). Despite normotensive systolic BP means in TBPM (133.5 ± 18.2 mmHg) and ABPM (24 h: 122.8 ± 14.7 mmHg), AHT persisted in up to 67.6% of all patients, with ABPM uncovering nocturnal systolic non- or reversed dipping in 89.5% and 53.3%, respectively. The latter was predominant (85.7%) in the hemorrhagic subgroup which also displayed lower daytime SBP than the ischemic one (ABPM: 117.1 ± 11.8 vs 124.7 ± 14.7 mmHg, p = 0.033). Further differences were present among distinct brain lesion types. Sufficient dippers were younger (58 ± 12 vs 75 ± 11 years, p < 0.001), but adjusting for age yielded no independent correlations. In spite of normotensive daytime BP measurements, ABPM detects latent AHT and insufficient nocturnal BP dipping after the acute phase of stroke. Further studies are needed to elucidate the role of increased nocturnal BP in patients after stroke.