Association of inflammation and oxidative stress with obstructive sleep apnea in ischemic stroke patients

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.

Unraveling the Complexities of Oxidative Stress and Inflammation Biomarkers in Obstructive Sleep Apnea Syndrome: A Comprehensive Review

BACKGROUND

Obstructive sleep apnea syndrome (OSAS), affecting approximately 1 billion adults globally, is characterized by recurrent airway obstruction during sleep, leading to oxygen desaturation, elevated carbon dioxide levels, and disrupted sleep architecture. OSAS significantly impacts quality of life and is associated with increased morbidity and mortality, particularly in the cardiovascular and cognitive domains. The cyclic pattern of intermittent hypoxia in OSAS triggers oxidative stress, contributing to cellular damage. This review explores the intricate relationship between OSAS and oxidative stress, shedding light on molecular mechanisms and potential therapeutic interventions.

METHODS

A comprehensive review spanning from 2000 to 2023 was conducted using the PubMed, Cochrane, and EMBASE databases. Inclusion criteria encompassed English articles focusing on adults or animals and reporting values for oxidative stress and inflammation biomarkers.

RESULTS

The review delineates the imbalance between pro-inflammatory and anti-inflammatory factors in OSAS, leading to heightened oxidative stress. Reactive oxygen species biomarkers, nitric oxide, inflammatory cytokines, endothelial dysfunction, and antioxidant defense mechanisms are explored in the context of OSAS. OSAS-related complications include cardiovascular disorders, neurological impairments, metabolic dysfunction, and a potential link to cancer. This review emphasizes the potential of antioxidant therapy as a complementary treatment strategy.

CONCLUSIONS

Understanding the molecular intricacies of oxidative stress in OSAS is crucial for developing targeted therapeutic interventions. The comprehensive analysis of biomarkers provides insights into the complex interplay between OSAS and systemic complications, offering avenues for future research and therapeutic advancements in this multifaceted sleep disorder.

Study of the obstructive sleep apnea syndrome in cerebral infarction patients

Introduction

Obstructive Sleep Apnea Syndrome (OSAS) is the most common respiratory disorder during sleep. Many studies have shown an association between obstructive sleep apnea syndrome and stroke, and OSAS has not been adequately considered in Vietnam compared to the actual clinical dangers. This study aims to assess the prevalence and general characteristics of obstructive sleep apnea syndrome in patients with cerebral infarction and investigate the relationship between obstructive sleep apnea syndrome and the severity of cerebral infarction.

Methods

Descriptive cross-sectional study. We identified 56 participants from August 2018 to July 2019. Subacute infarcts were identified by neuroradiologists. For each participant, vascular risk factors, medications, clinical symptoms, and neurological examination were abstracted from the medical record. Patients were taken for history and clinical examination. The patients were divided into two groups according to their AHI (Apnea-Hypopnea Index) (<5 and ≥5).

Results

A total of 56 patients were registered for the study. The mean age is 67.70 ± 11.07. The proportion of men is 53.6%. AHI has a positive correlation with neck circumference (r = 0.4), BMI (r = 0.38), the Epworth Sleepiness Scale (r = 0.61), LDL cholesterol (r = 0.38), the Modified Rankin Scale (r = 0.49), NIHSS (National Institutes of Health Stroke Scale) (r = 0.53), and an inverse correlation with SpO₂ (r = 0.61).

Conclusion

Obstructive sleep apnea Syndrome is a factor in the prognosis of cerebral infarction as well as cardiovascular diseases such as hypertension. Thus, understanding the risk of stroke in people with sleep apnea is necessary and working with a doctor to diagnose and treat sleep apnea is important.

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.

Novel contact-kinin inhibitor sylvestin targets thromboinflammation and ameliorates ischemic stroke

Ischemic stroke is a leading cause of death and disability worldwide. Increasing evidence indicates that ischemic stroke is a thromboinflammatory disease in which the contact-kinin pathway has a central role by activating pro-coagulant and pro-inflammatory processes. The blocking of distinct members of the contact-kinin pathway is a promising strategy to control ischemic stroke. Here, a plasma kallikrein and active FXII (FXIIa) inhibitor (sylvestin, contained 43 amino acids, with a molecular weight of 4790.4 Da) was first identified from forest leeches (Haemadipsa sylvestris). Testing revealed that sylvestin prolonged activated partial thromboplastin time without affecting prothrombin time. Thromboelastography and clot retraction assays further showed that it extended clotting time in whole blood and inhibited clot retraction in platelet-rich plasma. In addition, sylvestin prevented thrombosis in vivo in FeCl3-induced arterial and carrageenan-induced tail thrombosis models. The potential role of sylvestin in ischemic stroke was evaluated by transient and permanent middle cerebral artery occlusion models. Sylvestin administration profoundly protected mice from ischemic stroke by counteracting intracerebral thrombosis and inflammation. Importantly, sylvestin showed no signs of bleeding tendency. The present study identifies sylvestin is a promising contact-kinin pathway inhibitor that can proffer profound protection from ischemic stroke without increased risk of bleeding.

The Association Between Insomnia and Atherosclerosis: A Brief Report

AIM

The objective of the study was to clarify the occurrence of atherosclerosis in patients with insomnia.

METHODS

A total of 60 patients with insomnia and 58 patients in a control group were selected to measure blood glucose, blood lipids and other biochemical and physiological indicators. Brachial-ankle pulse wave velocity (baPWV) was measured to assess arterial stiffness, and color Doppler ultrasound was used to examine carotid artery intima-media thickness (CIMT) and plaque incidence. These indicators were used to determine the occurrence and degree of carotid atherosclerosis, and to compare the differences between the two groups.

RESULTS

While there was no significant difference in biochemical or physiological indicators between the two groups (P > 0.05), the baPWV, CIMT, and incidence of carotid plaque in the insomnia group were higher than the control group. In addition, the baPWV, CIMT, and incidence of carotid plaque in the chronic insomnia group were higher than that in the short-term insomnia group. Multiple linear regression analysis was carried out to analyze the effects of insomnia, systolic blood pressure, blood glucose, triglycerides, cholesterol, BMI, age and low-density lipoprotein on atherosclerosis. The results showed that increased CIMT was significantly correlated with insomnia in atherosclerosis group (R²=0.27 on the left, R²=0.37 on the right, P < 0.001).

CONCLUSION

Insomnia correlated with increased arterial stiffness and carotid atherosclerosis, and as the duration of insomnia prolongs, the correlation between them became more obvious.

Variants of candidate genes associated with the risk of obstructive sleep apnea

BACKGROUND

The researches on the associations between different candidate genes and obstructive sleep apnea (OSA) are inconsistent. Here, we performed a comprehensive qualitative and quantitative analysis to estimate the contribution of variants from candidate genes to the risk of OSA.

METHODS

Qualitative analysis was conducted to find the relationships for all included genes. Then, quantitative analysis of both allele models and genotype models was applied to evaluate the risk variants for OSA. Furthermore, a similar analysis was performed in different ethnic groups.

RESULTS

We included 152 publications containing 75 genes for qualitative analysis. Among them, we included 93 articles containing 28 variants from 16 genes for quantitative analysis. Through allele models, we found 10 risk variants for OSA (rs1801133 of MTHFR, ɛ4 of ApoE, -1438G/A of 5-HT2A, -308G/A of TNF-α, Pro1019Pro of LEPR, rs1130864 and rs2794521 of CRP, D/I of ACE, LPR and VNTR of 5-HTT) with the ORs of 1.21-2.07 in global population. We found that the variant of ɛ2 of ApoE could uniquely decrease the risk of OSA in the East Asian subgroup, while the other 6 variants, including ɛ4 in ApoE, -308G/A in TNF-α, Pro1019Pro in LEPR, D/I in ACE, LPR and VNTR in 5-HTT, could increase the risk of OSA. As for the European subpopulation, we only found that -308G/A in TNF-α could increase the risk for OSA.

CONCLUSIONS

Eleven variants from the candidate genes are associated with the risk of OSA, which also show ethnicity differences in East Asian and European subgroups.

Oxidative Stress and Inflammation Biomarker Expression in Obstructive Sleep Apnea Patients

Obstructive Sleep Apnea Syndrome (OSAS) is a respiratory sleep disorder characterised by repeated episodes of partial or complete obstruction of the upper airway during the night. This obstruction usually occurs with a reduction (hypopnea) or complete cessation (apnea) of the airflow in the upper airways with the persistence of thoracic-diaphragmatic respiratory movements. During the hypopnea/apnea events, poor alveolar ventilation reduces the oxygen saturation in the arterial blood (SaO₂) and a gradual increase in the partial arterial pressure of carbon dioxide (PaCO₂). The direct consequence of the intermittent hypoxia is an oxidative imbalance, with reactive oxygen species production and the inflammatory cascade’s activation with pro and anti-inflammatory cytokines growth. Tumour necrosis factors, inflammatory cytokines (IL2, IL4, IL6), lipid peroxidation, and cell-free DNA have been found to increase in OSAS patients. However, even though different risk-related markers have been described and analysed in the literature, it has not yet been clarified whether specified inflammatory bio-markers better correlates with OSAS diagnosis and its clinical evolution/comorbidities. We perform a scientific literature review to discuss inflammatory and oxidative stress biomarkers currently tested in OSAS patients and their correlation with the disease’s severity and treatment.

Is the Oxidative Stress in Obstructive Sleep Apnea Associated With Cardiovascular Complications?-Systematic Review

Obstructive sleep apnea (OSA) is a prevalent, underdiagnosed disease and is considered an independent risk factor for cardiovascular disease. The exact mechanism of cardiovascular complications (CVC) development as a complication of OSA is not entirely understood. Oxidative stress is suspected to be the essential factor in initiating various comorbidities in OSA. Biomarkers of nonenzymatic lipid and protein peroxidation, DNA repair and antioxidant capabilities measured in serum, plasma and urine are frequently used to assess the presence of oxidative stress. We conducted a systematic review and quality assessment of available observational analytic studies to determine whether there is an association between oxidative stress and OSA in patients with prevalent CV disease compared to (a) patients with prevalent CV disease but no OSA, (b) patients with prevalent CV disease and less severe OSA and (c) patients with OSA and no overt CV disease. This systematic review demonstrated that, while oxidative stress is associated with OSA, there was no clear difference in the severity of oxidative stress between OSA patients with or without cardiovascular complications.

The relationship between inflammation and neurocognitive dysfunction in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS), a state of sleep disorder, is characterized by repetitive apnea, chronic hypoxia, oxygen desaturation, and hypercapnia. Previous studies have revealed that intermittent hypoxia (IH) conditions in OSAS patients elicited neuron injury (especially in the hippocampus and cortex), leading to cognitive dysfunction, a significant and extraordinary complication of OSAS patients. The repeated courses of airway collapse and obstruction in OSAS patients resulted in apnea and arousal during sleep, leading to IH and excessive daytime sleepiness (EDS) and subsequently contributing to the development of inflammation. IH-mediated inflammation could further trigger various types of cognitive dysfunction. Many researchers have found that, besides continuous positive airway pressure (CPAP) treatment and surgery, anti-inflammatory substances might alleviate IH-induced neurocognitive dysfunction. Clarifying the role of inflammation in IH-mediated cognitive impairment is crucial for potentially valuable therapies and future research in the related domain. The objective of this article was to critically review the relationship between inflammation and cognitive deficits in OSAS.

NOX4, MDA, IMA and oxidative DNA damage: can these parameters be used to estimate the presence and severity of OSA?

PURPOSE

Obstructive sleep apnoea (OSA) involves recurrent obstructive apnoeas and hypopnoeas which cause cyclic hypoxia, reoxygenation and formation of reactive oxygen species (ROS). We aimed to investigate a member of the nicotinamide adenine dinucleotide phosphate oxidase (NOX) family of enzymes, specifically (NOX4), not previously studied in humans, as well as 8-OHdG/106dG, MDA and IMA, which are known to be associated with oxidative stress. We also evaluated these parameters in predicting the presence and severity of OSA.

METHODS

All 120 subjects (90 with OSA, 30 healthy controls) underwent polysomnography and had blood serum samples taken at the same time of day. Subjects were grouped by presence and severity of OSA, and serum markers were compared among groups.

RESULTS

Age and body mass index were not significantly different among groups. In the OSA group, the levels of NOX4, IMA, MDA and 8-OHdG/106dG were significantly higher than in the healthy control group. NOX4 and other parameters were positively correlated with the severity of OSA. For all parameters, the highest levels were detected in patients with severe OSA.

CONCLUSIONS

The repeated hypoxia of OSA is associated with increases in the serum levels of inflammatory mediators such as MDA, IMA and 8-OHdG/106dG and the ROS NOX4. In this study, NOX4 and other markers were associated with the presence and severity of OSA.

Sleep and Stroke: New Updates on Epidemiology, Pathophysiology, Assessment, and Treatment

PURPOSE OF REVIEW

This review aims to discuss the most recent data on sleep disorders and stroke, highlighting relevant findings for the practicing neurologist or health providers who encounter patients with sleep disorders and stroke.

RECENT FINDINGS

Sleep apnea and abnormal sleep duration have the strongest association with stroke risk. Possible mechanisms include non-dipping of blood pressure during sleep, hypoxemia or reoxygenation leading to sympathetic activation, hypertension, atrial fibrillation and impaired cerebral hemodynamics. Treatment studies suggest that continuous positive airway pressure (CPAP) for sleep apnea could improve primary prevention of stroke, but data is equivocal for secondary prevention. However, CPAP could improve functional outcomes after stroke.

SUMMARY

Sleep disorders present an opportunity to improve stroke risk and functional outcomes. However, new strategies are needed to determine the patients at high-risk who would most likely benefit from targeted care. Novel methods for phenotyping sleep disorders could provide personalized stroke care to improve clinical outcomes and public health strategies.

Positional therapy for obstructive sleep apnoea

BACKGROUND

The modalities of therapy for obstructive sleep apnoea (OSA) include behavioural and lifestyle modifications, positional therapy, oral appliances, surgery and continuous positive airway pressure therapy (CPAP). Though CPAP has proven efficacy in treating OSA, adherence with CPAP therapy is suboptimal. Positional therapy (to keep people sleeping on their side) is less invasive and therefore expected to have better adherence. This review considered the efficacy of positional therapy compared to CPAP as well as positional therapy against no positional therapy. Devices designed for positional therapy include lumbar or abdominal binders, semi-rigid backpacks, full-length pillows, a tennis ball attached to the back of nightwear, and electrical sensors with alarms that indicate change in position.

OBJECTIVES

To compare the efficacy of positional therapy versus CPAP and positional therapy versus inactive control (sham intervention or no positional therapy intervention) in people with OSA.

SEARCH METHODS

We identified studies from the Cochrane Airways' Specialised Register (including CENTRAL, MEDLINE, Embase, CINAHL, AHMED and PsycINFO), ClinicalTrials.gov, and the World Health Organization trials portal (ICTRP). It also contains results derived from handsearching of respiratory journals and abstract books of major annual meetings. We searched all databases from their inception to September 2018, with no restrictions on language of publication or publication type.

SELECTION CRITERIA

We included randomised controlled trials comparing positional therapy with CPAP and positional therapy with inactive control.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted the data. We used a random-effects model in the meta-analysis to estimate mean differences and confidence intervals. We assessed certainty of evidence using the GRADE approach.

MAIN RESULTS

We included eight studies. The studies randomised 323 participants into two types of interventions. The comparison between positional therapy and CPAP included 72 participants, while the comparison between positional therapy and inactive control included 251 participants. Three studies used supine vibration alarm devices, while five studies used physical positioning like specially designed pillows or semirigid backpacks.Positional therapy versus CPAPThe three studies included for this comparison were randomised cross-over trials. Two studies found that there was no difference in Epworth Sleepiness Scale (ESS) scores between CPAP and positional therapy. Two studies showed that CPAP produced a greater reduction in Apnoea-Hypopnoea Index (AHI) with a mean difference (MD) of 6.4 events per hour (95% CI 3.00 to 9.79; low-certainty evidence) compared to positional therapy. Subjective adherence, evaluated in one study, was found to be significantly greater with positional therapy (MD 2.5 hours per night, 95% CI 1.41 to 3.59; moderate-certainty evidence).In terms of secondary outcomes, one study each reported quality-of-life indices and quality-of-sleep indices with no significant difference between the two groups. One study reported cognitive outcomes using multiple parameters and found no difference between the groups. There were insufficient data to comment on other secondary outcomes like respiratory disturbance index (RDI), and frequency and duration of nocturnal desaturation. None of the studies clearly reported adverse effects.Positional therapy versus inactive controlThree studies of positional therapy versus no intervention were randomised cross-over trials, while two studies were parallel-arm studies. Data from two studies showed that positional therapy significantly improved ESS scores (MD -1.58, 95% CI -2.89 to -0.29; moderate-certainty evidence). Positional therapy showed a reduction in AHI compared with control (MD -7.38 events per hour, 95% CI -10.06 to -4.7; low-certainty evidence). One study reported adherence. The number of participants who continued to use the device at two months was no different between the two groups (odds ratio (OR) 0.80, 95% CI 0.33 to 1.94; low-certainty evidence). The same study reported adverse effects, the most common being pain in the back and chest, and sleep disturbance but there was no significant difference between the two groups in terms of device discontinuation (OR 1.25, 95% CI 0.5 to 3.03; low-certainty evidence). One study each reported quality-of-life indices and quality-of-sleep indices, with no significant difference between the two groups. One study reported cognitive outcome, and found no difference between the groups. There was insufficient evidence to comment on other secondary outcomes (RDI, frequency and duration of nocturnal desaturation).

AUTHORS' CONCLUSIONS

The review found that CPAP has a greater effect on improving AHI compared with positional therapy in positional OSA, while positional therapy was better than inactive control for improving ESS and AHI. Positional therapy may have better adherence than CPAP. There were no significant differences for other clinically relevant outcomes such as quality of life or cognitive function. All the studies were of short duration. We are unable to comment on the long-term effects of the therapies. This is important, as most of the quality-of-life outcomes will be evident only when the therapies are given over a longer period of time. The certainty of evidence was low to moderate.

Proteomic Analysis of Hydroxysafflor Yellow A Against Cerebral Ischemia/Reperfusion Injury in Rats

Hydroxysafflor yellow A (HSYA), an active component from Chinese medicinal herb, has been applied to the prevention and treatment of cerebral ischemia/reperfusion injury (CIRI). To clarify the comprehensive mechanisms HSYA for stroke, we used label-free quantitative proteomic analysis to investigate the modulated proteins of rats subjected to CIRI and their alteration by HSYA. Neurological examination, infarct assessment, and biochemical assay were performed to validate the effects of HSYA, and the results indicated that HSYA played a significant role in brain protection. A total of 13 proteins were identified as overlapped proteins by label-free quantitative proteomic analysis. Gene Ontology and pathway analysis showed that these differentially expressed proteins were mainly enriched in the hypoxia-inducible factor 1 (HIF-1) signaling pathway. Furthermore, networks were constructed with respect to protein function interactions. The results suggested that seven proteins were identified as hub proteins between model and sham groups, while 25 proteins were identified as hub proteins between HSYA and model groups. In addition, the expressions of three overlapping proteins were validated by Western blot, and their levels were consistent with the results of label-free analysis. In conclusion, Eftud2, mTOR, Rab11, Ppp2r5e, and HIF-1 signaling pathways have been detected as key hub proteins and pathways in HSYA against CIRI through proteomic analysis. Our research has provided convincing explanations for the mechanism of HSYA against CIRI and the identified key proteins and pathways might provide novel therapeutics for CIRI.

Obstructive sleep apnea is associated with increased coronary plaque instability: an optical frequency domain imaging study

Obstructive sleep apnea (OSA) is associated with coronary artery disease (CAD) and with an increased risk for myocardial infarction, stroke or death due to cardiovascular disease. Optical frequency-domain imaging (OFDI) is a useful modality for evaluating the characteristics of atherosclerotic plaque. The purpose of the study was to use OFDI to investigate the association of OSA with coronary plaque characteristics in patients undergoing percutaneous coronary intervention (PCI). We retrospectively analyzed OFDI data for coronary artery plaques from 15 patients with OSA and 35 non–OSA patients treated between October 2015 and October 2018. Plaque morphology was evaluated for 70 lesions, including 21 from patients with OSA and 49 from non–OSA patients. Compared with the non–OSA group, patients with OSA had significantly higher prevalences of thinned cap fibroatheroma (TCFA) (67% vs. 35%, P = 0.014) and microchannels (86% vs. 55%, P = 0.014); a significantly higher mean lipid index (1392 ± 982 vs. 817 ± 699, P = 0.021), macrophage grade (8.4 ± 6.4 vs. 4.8 ± 4.5, P = 0.030), and maximum number of microchannels (1.5 ± 1.0 vs. 0.7 ± 0.7, P = 0.001); and a significantly lower mean minimum fibrous cap thickness (69.4 ± 28.7 vs. 96.1 ± 51.8 μm, P = 0.008). This OFDI analysis suggests that OSA is associated with unstable plaque characteristics in patients with CAD. More intensive medical management for stabilization of coronary atherosclerotic plaque is required in patients with OSA.

Obstructive Sleep Apnea in Children and Adolescents and the Risk of Major Adverse Cardiovascular Events: A Nationwide Cohort Study in Taiwan

STUDY OBJECTIVES

This study has investigated the risk of major adverse cardiovascular events (MACEs), including acute myocardial infarction, coronary artery disease, peripheral artery disease, and acute stroke, among children and adolescents (age younger than 20 years) with obstructive sleep apnea (OSA).

METHODS

In this study, the population-based National Health Insurance Research Database of Taiwan was used to identify patients in whom OSA had been first diagnosed between 2000 and 2015. Children and adolescents with OSA (n = 6,535) were included with 1:3 ratio by age, sex, and index year of control participants without OSA (n = 19,605). The Cox proportional regression model was used to evaluate the risk of MACEs in this cohort study.

RESULTS

After a 15-year follow-up, the incidence rate of MACEs was higher in the OSA cohort when compared with the non-OSA control cohort (15.97 and 8.20 per 100,000 person-years, respectively). After adjusting for covariates, the risk of MACEs among children and adolescents with OSA was still significantly higher (hazard ratio = 2.050; 95% confidence interval = 1.312-3.107; P = .010). No MACEs were found in the children and adolescents with OSA who received continuous airway positive pressure treatment or pharyngeal surgery.

CONCLUSIONS

This study found a significantly higher risk of MACEs in children and adolescents with OSA. These findings strongly suggest that clinicians should provide careful follow-up and medical treatment for children and adolescents with OSA.

Sleep, Autonomic Nervous Function and Atherosclerosis

Behavioral and psychosocial factors related to development of cardiovascular disease have been gaining increased attention. Notably, sleep is considered to be one of the most important behavioral factors involved in progression of atherosclerosis and cardiovascular events, with autonomic nervous function a potential mechanism. Several studies have shown associations of sleep and autonomic dysfunction with major surrogate markers of atherosclerosis, such as carotid intima-media thickness and arterial stiffness. Endocrinological, immunological, oxidative, inflammatory, and metabolic responses, as well as endothelial dysfunction may mediate the effects of the autonomic nervous system. For this review, we examined recent findings related to sleep, autonomic nervous dysfunction, and atherosclerosis, with the aim of understanding the involved pathophysiological mechanisms.

Antineuroinflammation of Minocycline in Stroke

Accumulating research substantiates the statement that inflammation plays an important role in the development of stroke. Both proinflammatory and anti-inflammatory mediators are involved in the pathogenesis of stroke, an imbalance of which leads to inflammation. Anti-inflammation is a kind of hopeful strategy for the prevention and treatment of stroke. Substantial studies have demonstrated that minocycline, a second-generation semisynthetic antibiotic belonging to the tetracycline family, can inhibit neuroinflammation, inflammatory mediators and microglia activation, and improve neurological outcome. Experimental and clinical data have found the preclinical and clinical potential of minocycline in the treatment of stroke due to its anti-inflammation properties and anti-inflammation-induced pathogeneses, including antioxidative stress, antiapoptosis, inhibiting leukocyte migration and microglial activation, and decreasing matrix metalloproteinases activity. Hence, it suggests a great future for minocycline in the therapeutics of stroke that diminish the inflammatory progress of stroke.

Serum Romo1 is significantly associated with disease severity in patients with obstructive sleep apnea syndrome

PURPOSE

We aim to evaluate reactive oxygen species modulator 1 (Romo1) levels in obstructive sleep apnea syndrome (OSAS) and analyze its possible relationships to OSAS severity, reactive oxygen species (ROS), and C-reactive protein (CRP). Additionally, we also investigated the effects of nasal continuous positive airway pressure (nCPAP) on serum Romo1.

METHODS

One hundred and five patients diagnosed with OSAS were classified into the OSAS group, and 41 subjects without OSAS were recruited for the control group. The OSAS group was further divided into mild, moderate, and severe OSAS subgroups. Fifteen patients with moderate and severe OSAS were treated with nCPAP. Serum levels of Romo1, ROS, and CRP were also measured.

RESULTS

Serum Romo1, ROS, and CRP were the lowest in normal subjects and increased across OSAS severities (P < 0.05). Univariate analysis showed that serum Romo1 was positively correlated with apnea-hypopnea index (AHI), oxygen desaturation index (ODI), time spent below 90% oxygen saturation (Ts90%), arousal index, ROS, and CRP, and was negatively correlated with minimal oxygen saturation (miniSaO₂) (all P < 0.05). Multiple linear regression analysis showed that serum Romo1 level was significantly associated with AHI and ODI, after adjusting for age, gender, BMI, and CRP. After 6 months of nCPAP therapy, serum Romo1, ROS, and CRP were significantly decreased (P < 0.05).

CONCLUSIONS

The increase of serum Romo1 in OSAS patients was positively correlated with disease severity. Serum Romo1 may be an important parameter for monitoring the severity of OSAS and treatment efficiency.

Methodological strategies in using home sleep apnea testing in research and practice

PURPOSE

Home sleep apnea testing (HSAT) has increased due to improvements in technology, accessibility, and changes in third party reimbursement requirements. Research studies using HSAT have not consistently reported procedures and methodological challenges. This paper had two objectives: (1) summarize the literature on use of HSAT in research of adults and (2) identify methodological strategies to use in research and practice to standardize HSAT procedures and information.

METHODS

Search strategy included studies of participants undergoing sleep testing for OSA using HSAT. MEDLINE via PubMed, CINAHL, and Embase with the following search terms: "polysomnography," "home," "level III," "obstructive sleep apnea," and "out of center testing."

RESULTS

Research articles that met inclusion criteria (n = 34) inconsistently reported methods and methodological challenges in terms of: (a) participant sampling; (b) instrumentation issues; (c) clinical variables; (d) data processing; and (e) patient acceptability. Ten methodological strategies were identified for adoption when using HSAT in research and practice.

CONCLUSIONS

Future studies need to address the methodological challenges summarized in this paper as well as identify and report consistent HSAT procedures and information.

A Preliminary Investigation of the Association of Sleep With Inflammation and Oxidative Stress Biomarkers and Functional Outcomes After Stroke Rehabilitation

This study examined the association of sleep with inflammation and oxidative stress biomarkers, and with functional outcomes, after stroke rehabilitation. The rehabilitation effects on biomarkers and functional outcomes were also evaluated. Twenty subacute stroke survivors received 4 weeks of upper limb rehabilitation. Baseline inflammatory (i.e., soluble intercellular adhesion molecule-1, sICAM-1) and oxidative stress biomarkers (i.e., glutathione peroxidase, GPx and malondialdehyde, MDA) were assessed, as were sleep outcomes. Positive correlations were observed between baseline level of sICAM-1 and number of awakenings at post-treatment (ρ = 0.51, p < 0.05) as well as between baseline level of MDA and post-performance time of the Wolf Motor Function Test (WMFT-time) (ρ = 0.46, p < 0.05). In addition, MDA levels were significantly decreased, and functional outcomes of the modified Rankin Scale (mRS), functional ability scale of the WMFT, and Stroke Impact Scale (SIS-total, and SIS-physical function) were improved after the rehabilitation. This pilot study emphasizes the relationship among biomarkers, sleep, and functional outcomes after stroke rehabilitation. Oxidative stress markers may be useful predictors of functional outcomes in subacute stroke survivors.

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.

Obstructive sleep apnea is independently associated with arterial stiffness in ischemic stroke patients

Obstructive sleep apnea (OSA) is a predictor of all-cause mortality and recurrent vascular events following stroke. However, few studies have investigated the pathophysiology of OSA in ischemic stroke patients. Whether OSA independently increases arterial stiffness in ischemic stroke patients is determined by measuring the carotid-femoral pulse wave velocity (PWV) and via the central augmentation index (AIx). This cross-sectional study consecutively recruited 127 subacute ischemic stroke patients who were admitted to a teaching hospital for inpatient rehabilitation (median age, 61.3 years; IQR 53.6-72.7 years). Vascular measurements were performed following polysomnography. Multivariate linear regression analysis was performed to determine the relationship between arterial stiffness and OSA. Patients with severe OSA were significantly older, had significantly higher PWV and mean blood pressure, and a significantly higher risk of hypertension than those with non-severe OSA. The significant bivariate correlation between AIx@75 and the desaturation index (DI) (Spearman's ρ = 0.182, P = 0.040) became insignificant by multivariate regression analysis. The PWV was significantly correlated with the apnea-hypopnea index (AHI) (Pearson's r = 0.350, P = 0.000) and DI (Spearman's ρ = 0.347, P = 0.000). The correlation between PWV and OSA parameters, including presence of severe OSA, AHI and DI, remained significant by multivariate regression analysis with age, systolic blood pressure, diabetic mellitus, hypertension and the Barthel index as potential confounders. Arterial stiffness is independently associated with OSA, and PWV can be applied as an intermediate endpoint in further intervention trials of ischemic stroke patients with OSA.