Physical activity in the prevention of ischemic stroke and improvement of outcomes: a narrative review

Reassessing the Association of Sedentary Behavior and Physical Activity with Ischemic Stroke: A Mendelian Randomization Study

PURPOSE

Findings from previous Mendelian randomization (MR) studies disagreed with the current scientific consensus regarding the role of physical activity (PA) and sedentary behavior in ischemic stroke (IS). We reassessed these associations with a focus on etiological subtypes of IS and the potential mediating roles of cardiometabolic traits and brain imaging-derived phenotypes (IDPs).

METHODS

We performed MR analyses using summary statistics from genome-wide association studies of sedentary behavior and PA ( n = 88,411 ~ 608,595), cardiometabolic traits ( n = 393,193 ~ 694,649), brain IDPs ( n = 33,224), and the latest IS data (62,100 cases and 1,234,808 controls). Inverse-variance weighted regression was used as the primary method, complemented by several sensitivity analyses. A two-step MR approach was employed to assess the mediating effects of cardiometabolic traits and brain IDPs.

RESULTS

Genetic liability to leisure-time moderate-to-vigorous PA (MVPA) and higher overall PA (OPA) were associated with reduced risks of IS and small vessel stroke (Benjamini-Hochberg adjusted P < 0.05). Suggestive associations were observed between longer leisure-screen time and higher IS risk and between higher OPA and lower cardioembolic stroke risk ( P < 0.05). The isotropic volume fraction in the anterior limb of the left internal capsule, as well as some cardiometabolic metrics, partially mediated these associations. There was no evidence for causal effects of overall MVPA, overall light-intensity PA, or overall sedentary duration on IS.

CONCLUSIONS

Longer leisure screen time, less OPA, and not engaging in MVPA during leisure time were associated with higher risk of IS. The associations between PA and IS depended on different subtypes and were mediated by changes in anterior limb of the left internal capsule and cardiometabolic biomarkers.

Genetic associations between physical activity levels and functional outcome after ischemic stroke: Insights from Mendelian randomization

OBJECTIVE

The genetic relationship between daily physical activity (PA) levels and functional outcome after ischemic stroke remains unclear. This study aimed to investigate the genetic associations of PA on functional outcome after ischemic stroke using Mendelian randomization (MR).

METHODS

We conducted two-sample MR analyses using genome-wide association studies (GWASs). This included data on light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) from the UK Biobank, and functional outcome after ischemic stroke from the Genetics of ischemic stroke Functional Outcome (GISCOME). The inverse-variance weighted (IVW) method served as our primary MR analysis approach, supplemented by several sensitivity analyses.

RESULTS

In univariable Mendelian randomization (UVMR) analysis, MVPA was significantly associated with a reduced risk of poor functional outcome (OR = 0.15, 95 % CI = 0.04-0.56, P < 0.01), whereas LPA had no genetic relationship (OR = 0.37, 95 % CI = 0.002-51.40, P = 0.69). In multivariate Mendelian randomization (MVMR) analysis adjusting for potentially confounding traits including hypertension, type 2 diabetes, and smoking, the overall patterns between MVPA and poststroke outcome remained (OR = 0.23, 95 % CI = 0.07-0.78, P = 0.02).

CONCLUSION

MVPA is a protective factor for functional outcome after ischemic stroke. This finding is important for the rehabilitation and functional outcome of stroke patients.

Adherence to oxidative balance score is inversely associated with the prevalence of stroke: results from National Health and Nutrition Examination Survey 1999-2018

Introduction

The relationship between oxidative balance score (OBS), an emerging integrative metric for assessing individual redox homeostasis, and the prevalence of stroke in the general population remains unknown. We aimed to explore these relationships in the National Health and Nutrition Examination Survey (NHANES). We investigated the relationship between the oxidative balance score (OBS) and stroke prevalence using NHANES data from 1999-2018.

Methods

We included eligible individuals from NHANES 1999-2018. OBS calculations were based on previously validated methods, and stroke diagnoses were based on self-reports in questionnaires. Multivariable logistic regression analyses were used to examine the independent associations of overall, dietary, and lifestyle OBS with stroke prevalence. In addition, restricted cubic spline (RCS), stratified analysis, and sensitivity analysis were used.

Results

We included 25,258 participants aged 20-85 years, in which the prevalence of stroke was 2.66%. After adjusting for all confounders, overall and dietary OBS, but not lifestyle OBS, were inversely associated with the prevalence of stroke [odds ratios and 95% confidence intervals of 0.97 (0.96, 0.99) and 0.98 (0.96, 0.99) for overall and dietary OBS, respectively, both p < 0.05]. In addition, there was a dose-response relationship between overall and dietary OBS and stroke prevalence. The RCS showed that these relationships were linear. Stratified analyses indicated that socioeconomic status (SES) significantly influenced the relationship between all OBS and stroke prevalence.

Conclusion

Dietary OBS, but not lifestyle OBS, had an inverse relationship with the prevalence of stroke in the general population. SES significantly influenced the protective effect of OBS against stroke. These findings emphasize the importance of integrated antioxidant properties from diet for stroke prevention.

The paradigm change from reactive medical services to 3PM in ischemic stroke: a holistic approach utilising tear fluid multi-omics, mitochondria as a vital biosensor and AI-based multi-professional data interpretation

Worldwide stroke is the second leading cause of death and the third leading cause of death and disability combined. The estimated global economic burden by stroke is over US$891 billion per year. Within three decades (1990-2019), the incidence increased by 70%, deaths by 43%, prevalence by 102%, and DALYs by 143%. Of over 100 million people affected by stroke, about 76% are ischemic stroke (IS) patients recorded worldwide. Contextually, ischemic stroke moves into particular focus of multi-professional groups including researchers, healthcare industry, economists, and policy-makers. Risk factors of ischemic stroke demonstrate sufficient space for cost-effective prevention interventions in primary (suboptimal health) and secondary (clinically manifested collateral disorders contributing to stroke risks) care. These risks are interrelated. For example, sedentary lifestyle and toxic environment both cause mitochondrial stress, systemic low-grade inflammation and accelerated ageing; inflammageing is a low-grade inflammation associated with accelerated ageing and poor stroke outcomes. Stress overload, decreased mitochondrial bioenergetics and hypomagnesaemia are associated with systemic vasospasm and ischemic lesions in heart and brain of all age groups including teenagers. Imbalanced dietary patterns poor in folate but rich in red and processed meat, refined grains, and sugary beverages are associated with hyperhomocysteinaemia, systemic inflammation, small vessel disease, and increased IS risks. Ongoing 3PM research towards vulnerable groups in the population promoted by the European Association for Predictive, Preventive and Personalised Medicine (EPMA) demonstrates promising results for the holistic patient-friendly non-invasive approach utilising tear fluid-based health risk assessment, mitochondria as a vital biosensor and AI-based multi-professional data interpretation as reported here by the EPMA expert group. Collected data demonstrate that IS-relevant risks and corresponding molecular pathways are interrelated. For examples, there is an evident overlap between molecular patterns involved in IS and diabetic retinopathy as an early indicator of IS risk in diabetic patients. Just to exemplify some of them such as the 5-aminolevulinic acid/pathway, which are also characteristic for an altered mitophagy patterns, insomnia, stress regulation and modulation of microbiota-gut-brain crosstalk. Further, ceramides are considered mediators of oxidative stress and inflammation in cardiometabolic disease, negatively affecting mitochondrial respiratory chain function and fission/fusion activity, altered sleep-wake behaviour, vascular stiffness and remodelling. Xanthine/pathway regulation is involved in mitochondrial homeostasis and stress-driven anxiety-like behaviour as well as molecular mechanisms of arterial stiffness. In order to assess individual health risks, an application of machine learning (AI tool) is essential for an accurate data interpretation performed by the multiparametric analysis. Aspects presented in the paper include the needs of young populations and elderly, personalised risk assessment in primary and secondary care, cost-efficacy, application of innovative technologies and screening programmes, advanced education measures for professionals and general population-all are essential pillars for the paradigm change from reactive medical services to 3PM in the overall IS management promoted by the EPMA.

Stroke and cognitive impairment: understanding the connection and managing symptoms

Stroke is a leading cause of long-term disability worldwide, and cognitive impairment is a common consequence of stroke. Understanding the connection between stroke and cognitive impairment is crucial for effectively managing symptoms and improving patients' quality of life. This abstract provides an overview of the relationship between stroke and cognitive impairment and explores strategies for managing cognitive symptoms in stroke survivors. A comprehensive review of relevant literature was conducted to examine the association between stroke and cognitive impairment. Various factors contributing to cognitive impairment after stroke were explored, including the location and severity of the stroke, vascular risk factors, and underlying mechanisms. Evidence-based strategies for managing cognitive symptoms in stroke survivors were also analyzed, such as cognitive rehabilitation, pharmacological interventions, and lifestyle modifications. The review revealed a strong link between stroke and cognitive impairment. The location and severity of the stroke play a significant role in determining the specific cognitive deficits experienced by individuals. Vascular risk factors, including hypertension, diabetes, and atrial fibrillation, contribute to cognitive decline after stroke. Mechanisms such as cerebral hypoperfusion, white matter damage, and neuroinflammation also play a role. Cognitive rehabilitation programs have shown promising results in improving cognitive function, while certain medications may help manage specific cognitive symptoms. Lifestyle modifications like physical exercise and a healthy diet have been associated with better cognitive outcomes in stroke survivors.

Physical activity and brain health in patients with atrial fibrillation

BACKGROUND AND PURPOSE

Vascular brain lesions, such as ischemic infarcts, are common among patients with atrial fibrillation (AF) and are associated with impaired cognitive function. The role of physical activity (PA) in the prevalence of brain lesions and cognition in AF has not been investigated.

METHODS

Patients from the multicenter Swiss-AF cohort study were included in this cross-sectional analysis. We assessed regular exercise (RE; at least once weekly) and minutes of weekly PA using a validated questionnaire. We studied associations with ischemic infarcts, white matter hyperintensities, cerebral microbleeds, and brain volume on brain magnetic resonance imaging and with global cognition measured with a cognitive construct (CoCo) score.

RESULTS

Among 1490 participants (mean age = 72 ± 9 years), 730 (49%) engaged in RE. In adjusted regression analyses, RE was associated with a lower prevalence of ischemic infarcts (odds ratio [OR] = 0.78, 95% confidence interval [CI] = 0.63-0.98, p = 0.03) and of moderate to severe white matter hyperintensities (OR = 0.78, 95% CI = 0.62-0.99, p = 0.04), higher brain volume (β-coefficient = 10.73, 95% CI = 2.37-19.09, p = 0.01), and higher CoCo score (β-coefficient = 0.08, 95% CI = 0.03-0.12, p < 0.001). Increasing weekly PA was associated with higher brain volume (β-coefficient = 1.40, 95% CI = 0.65-2.15, p < 0.001).

CONCLUSIONS

In AF patients, RE was associated with a lower prevalence of ischemic infarcts and of moderate to severe white matter disease, with larger brain volume, and with better cognitive performance. Prospective studies are needed to investigate whether these associations are causal. Until then, our findings suggest that patients with AF should be encouraged to remain physically active.

Association Between Change in Leisure-Time Physical Activity During the Postretirement Period and Incident Stroke

BACKGROUND AND OBJECTIVES

To investigate the association of change in leisure-time physical activity (LTPA) occurring during the postretirement period with incident stroke.

METHODS

The current study enrolled 12,644 retired workers from the Dongfeng-Tongji cohort from April to October 2013. The change in LTPA was categorized as follows, according to whether the LTPA time met the WHO recommended minimum (at least 150 minutes per week): (1) stayed inactive at both surveys; (2) stayed inactive at the 2008 survey but became active at the 2013 survey; (3) stayed active at the 2008 survey but became inactive at the 2013 survey; (4) stayed active at both surveys. We used multivariable-adjusted Cox proportional hazards regression models to examine the association between change in LTPA and the risk of incident stroke.

RESULTS

During 70,437 person-years of follow-up, we documented 549 incident stroke cases, including 434 incident ischemic stroke cases and 115 incident hemorrhagic stroke (HS) cases. Compared with participants who stayed active at both the 2008 and 2013 surveys, those who were active at the 2008 survey but became inactive at the 2013 survey had significantly higher risks of incident total stroke (hazard ratio [HR] 1.30, 95% CI 1.03, 1.65) and HS (HR 2.34, 95% CI 1.51, 3.63). When stratified by body mass index (BMI) categories, a significant elevated risk of total stroke was seen among overweight participants who stayed active at the 2008 survey but became inactive at the 2013 survey (HR 1.65, 95% CI 1.20, 2.27). The risk of incident stroke decreased with increasing LTPA levels between the 2 surveys (HR of per 150 min/wk increase of LTPA: HR 0.97, 95% CI 0.94, 1.00). In addition, we found that compared with participants who maintained their BMI and stayed active at both the 2008 and 2013 surveys, those who were inactive at both points or who became inactive had higher risks of stroke (HR 2.13, 95% CI 1.09, 4.15; HR 1.50, 95% CI 1.07, 2.08, respectively).

DISCUSSION

Among Chinese older adults, increasing LTPA levels during the postretirement period was associated with a lower risk of incident stroke. Retired individuals should be encouraged to participate in LTPA more frequently to lessen future risk of incident stroke.

Treadmill Exercise Attenuates Cerebral Ischemia-Reperfusion Injury by Promoting Activation of M2 Microglia via Upregulation of Interleukin-4

Background: Exercise has been proven to be an effective therapy for stroke by reducing the microglia-initiated proinflammatory response. Few studies, however, have focused on the phenotypic changes in microglia cells caused by exercise training. The present study was designed to evaluate the influence of treadmill exercise on microglia polarization and the molecular mechanisms involved. Methods: Male Sprague-Dawley rats were randomly assigned into 3 groups: sham, MCAO and exercise. The middle cerebral artery occlusion (MCAO) and exercise groups received MCAO surgery and the sham group a sham operation. The exercise group also underwent treadmill exercise after the surgery. These groups were studied after 4 and 7 days to evaluate behavioral performance using a modified neurological severity score (mNSS), and infarct conditions using 2,3,5-triphenyl tetrazolium chloride. Quantitative real-time polymerase chain reaction (qRT-PCR) and Luminex was employed to determine the expressions of markers of microglia phenotypes. Western blotting was employed to identify the phosphorylation levels of Janus kinase1 (JAK1) and signal transducer and activator of transcription 6 (STAT6). Immunofluorescence was conducted to identify microglia phenotypes. Results: Treadmill exercise was found to improve neurobehavioral outcomes, mainly motor and balance functions, reduce infarct volumes and significantly increase interleukin-4 (IL-4) expression. In addition, treadmill exercise inhibited M1 microglia and promoted M2 microglia activation as evidenced by decreased M1 and increased M2 markers. Furthermore, an obvious increase in p-JAK1 and p-STAT6 was observed in the exercise group. Conclusions: Treadmill exercise ameliorates cerebral ischemia-reperfusion injury by enhancing IL-4 expression to promote M2 microglia polarization, possibly via the JAK1-STAT6 pathway.

Knowledge, Prevention Practice and Associated Factors of Stroke Among Hypertensive and Diabetic Patients - A Systematic Review

INTRODUCTION

Because of the inadequate level of public awareness of the disease, the incidence of stroke has been sharply rising. Eventually, due to the prehospital delay, many stroke cases could not be eligible for thrombolysis thereby poor rehabilitative outcome has been tremendously increased. Thus, this study aimed to review the level of knowledge, prevention practice, and associated factors of stroke among hypertensive and diabetic patients.

METHODS

A systematic review of primarily published articles (2010-2020) related to knowledge and prevention practices of stroke was performed by searching online electronic databases like PubMed, Google Scholar, Refseek, Science direct, ResearchGate, and manual Google search by using the keywords and MeSH terms. Studies conducted on knowledge and prevention practices amongst hypertensive and/or diabetic patients were included.

RESULTS

Out of 531 searched studies, 42 articles were identified to be reviewed. The reported overall knowledge of stroke was ranging from 4.4% to 79%. Knowledge to the signs/symptoms of stroke was 23.6% to 87%. However, 15% to 77% of subjects were also reported that they did not know any sign of stroke. The range of risk factor knowledge was 10.5% to 86.6%. The reported level of stroke prevention practice was 2.4% to 72% but physical activity and weight reduction practice were relatively low. Inadequate level of knowledge and prevention practice of stroke was related to elderly, female gender, uneducated, unmarried, rural residents, economically low, comorbidity and unemployed individuals.

CONCLUSION

The current finding revealed that the level of knowledge and prevention practice of stroke was inadequate. Hence, the finding highlights health educational programs should be planned as an important avenue to enhance stroke awareness among the high-risk populations.

Reshaping the path of vascular cognitive impairment with resistance training: a study protocol for a randomized controlled trial

Background

Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. Importantly, SIVCI is considered the most treatable form of cognitive impairment in older adults, due to its modifiable risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia. Exercise training is a promising intervention to delay the progression of SIVCI, as it actively targets these cardiometabolic risk factors. Despite the demonstrated benefits of resistance training on cognitive function and emerging evidence suggesting resistance training may reduce the progression of white matter hyperintensities (WMHs), research on SIVCI has predominantly focused on the use of aerobic exercise. Thus, the primary aim of this proof-of-concept randomized controlled trial is to investigate the efficacy of a 12-month, twice-weekly progressive resistance training program on cognitive function and WMH progression in adults with SIVCI. We will also assess the efficiency of the intervention.

Methods

Eighty-eight community-dwelling adults, aged > 55 years, with SIVCI from metropolitan Vancouver will be recruited to participate in this study. SIVCI will be determined by the presence of cognitive impairment (Montreal Cognitive Assessment < 26) and cerebral small vessel disease using computed tomography or magnetic resonance imaging. Participants will be randomly allocated to a twice-weekly exercise program of (1) progressive resistance training or (2) balance and tone training (i.e., active control). The primary outcomes are cognitive function measured by the Alzheimer’s Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-13 with additional cognitive tests) and WMH progression.

Discussion

The burden of SIVCI is immense, and to our knowledge, this will be the first study to quantify the effect of progressive resistance training on cognitive function and WMH progression among adults with SIVCI. Slowing the rate of cognitive decline and WMH progression could preserve functional independence and quality of life. This could lead to reduced health care costs and avoidance of early institutional care.

Trial registration

ClinicalTrials.gov NCT02669394. Registered on February 1, 2016

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05156-1.

Predicting exercise after university: an application of the reasoned action approach across a significant life transition

The present study applied an extended version of the reasoned action approach (RAA) to explain students' post-university exercise intentions and behaviour. Students (N = 136) completed measures of RAA variables, past behaviour, habit strength and self-identity before leaving university, and exercise behaviour six months later (n = 84). The RAA explained 67% of the variance in exercise intentions (experiential attitude, instrumental attitude and autonomy were significant predictors), and 20% of the variance in behaviour (experiential attitude and intention were significant predictors). Past behaviour explained additional variance in exercise intentions and behaviour, but its effects were mediated by self-identity. The RAA provides a useful framework for understanding students' exercise intentions and behaviour as they transition out of university. Self-identity may be particularly important for maintaining exercise levels across significant life transitions.

Therapeutic effectiveness of a single exercise session combined with WalkAide functional electrical stimulation in post-stroke patients: a crossover design study

A growing body of evidence has suggested that the imbalance of epigenetic markers and oxidative stress appears to be involved in the pathophysiology and progression of stroke. Thus, strategies that modulate these biomarkers might be considered targets for neuroprotection and novel therapeutic opportunities for these patients. Physical exercise has been reported to induce changes in these epigenetic markers and improve clinical outcomes in different populations. However, little is reported on this in post-stroke patients. The purpose of this study was to investigate the effect of a single exercise session with WalkAide functional electrical stimulation (FES) on cognitive performance, clinical functional parameters, oxidative stress and epigenetic modulation in post-stroke individuals. In this crossover design study, 12 post-stroke individuals aged 54–72 years of either sexes were included and subjected to a single session of exercise (45 minutes) without WalkAide functional electrical stimulation (EXE alone group), followed by another single session of exercise (45 minutes) with WalkAide functional electrical stimulation (EXE + FES group). The clinical functional outcome measures, cognitive performance and blood collections for biomarker measurements were assessed pre- and post-intervention. After intervention, higher Berg Balance Scale scores were obtained in the EXE + FES group than in the EXE alone group. There was no significant difference in the Timed Up and Go test results post-intervention between EXE alone and EXE + FES groups. After intervention, a better cognitive performance was found in both groups compared with before the intervention. After intervention, the Timed Up and Go test scores were higher in the EXE + FES group than in the EXE alone group. In addition, the intervention induced lower levels of lipid peroxidation. After intervention, carbonyl level was lower, superoxide dismutase activity and superoxide dismutase/catalase activity ratio were higher in the EXE + FES group, compared with the EXE group alone. In each group, both histone deacetylase (HDAC2) and histone acetyltransferase activities were increased after intervention compared with before the intervention. These findings suggest that a single exercise session with WalkAide FES is more effective on balance ability and cognitive performance compared with conventional exercise alone in post-stroke patients. This is likely to be related to the regulation of oxidative stress markers. The present study was approved by the Research Ethics Committee of the Methodist University Center-IPA (approval No. 2.423.376) on December 7, 2017 and registered in the Brazilian Registry of Clinical Trials—ReBEC (RBR-9phj2q) on February 11, 2019.

Prestroke Physical Activity and Poststroke Cognitive Performance

INTRODUCTION

Physical activity (PA) is associated with a lower risk of stroke and stroke mortality as well as a favorable stroke outcome. PA may also prevent general cognitive decline. Poststroke cognitive impairment is both common and disabling, and focusing on all possible preventive measures is important. Studies on the effect of PA on poststroke cognitive performance are sparse, however. We therefore aimed to examine the association between prestroke PA and poststroke cognitive performance.

METHODS

We studied the correlation between prestroke PA and poststroke cognitive performance in a prespecified analysis in The Efficacy of Citalopram Treatment in Acute Ischemic Stroke (TALOS) trial. We used the Physical Activity Scale for the Elderly (PASE) to collect information on PA during the 7-day period before stroke. PA was quantified, and patients were stratified into quartiles based on their PASE score. Cognitive performance was measured using the Symbol Digit Modalities Test (SDMT) at 1 and 6 months and the Mini-Mental State Examination (MMSE) at 6 months. The functional outcome was assessed using the modified Rankin Scale (mRS).

RESULTS

In total, 625 of 642 patients (97%) completed the PASE questionnaire. The median age was 69 (interquartile range [IQR]: 60-77), and the median PASE score was 137 (82-205). Higher prestroke PASE quartiles (2nd, 3rd, and 4th, each compared to the 1st) were independently associated with a higher SDMT score at 1 month in the both the univariable and multivariable analyses (2nd: 3.99 points, 95% confidence interval [CI]: 1.01-6.97; 3rd: 3.6, CI: 0.6-6.61; 4th: 4.1, CI: 0.95-7.24). This association remained at 6 months. PA was not statistically associated with the MMSE score or mRS.

CONCLUSION

Higher prestroke PA was associated with a better cognitive performance as measured by the SDMT at 1 and 6 months poststroke. We found no significant association between prestroke PA and functional outcome. Our results are encouraging and support further investigations of PA as a protective measure against poststroke cognitive impairment.

ΜicroRNA-221 participates in cerebral ischemic stroke by modulating endothelial cell function by regulating the PTEN/PI3K/AKT pathway

An effective method to improve the blood supply of brain tissue is by angiogenesis, which is crucial for the prognosis of patients with cerebral ischemic stroke (CIS). Therefore, angiogenesis has been a focus of CIS research in recent years. The present study aimed to investigate the expression of microRNA (miR)-221 in patients with CIS and to explore the effect of miR-221 on endothelial cell function. The level of miR-221 was detected using reverse transcription-quantitative PCR (RT-qPCR). The relationship between miR-221 and phosphatase and tensin homolog (PTEN) was predicted and confirmed by bioinformatics and dual luciferase reporter assay. Cell viability, migration and invasion, and cell apoptosis were determined using MTT assay, Transwell assay and flow cytometry respectively. Tube formation in human umbilical vein endothelial cells (HUVECs) was determined by performing the tube formation assay. In addition, protein levels were measured using western blot analysis. The results of the current study indicated that miR-221 levels were significantly decreased in the peripheral blood of patients with CIS. PTEN was confirmed to be a direct target of miR-221. Downregulation of miR-221 significantly inhibited the function of HUVECs as evidenced by the decreased cell viability, migration and invasion with increased cell apoptosis and tube formation inhibition. miR-221 upregulation produced the reverse effects, whilst all the effects of miR-221 upregulation on HUVECs were reversed by PTEN overexpression. The PI3K/AKT pathway was identified to be involved in the regulation of miR-221 on HUVECs. In conclusion, miR-221 was downregulated in CIS patients, and it promoted the function of HUVECs by regulating the PTEN/PI3K/AKT pathway in vitro, suggesting the ability to promote angiogenesis. Therefore, miR-221 may be a novel and promising therapeutic target for CIS treatment.

Neurogenesis promoted by the CD200/CD200R signaling pathway following treadmill exercise enhances post-stroke functional recovery in rats

Stroke is a leading cause of long-term disability worldwide; survivors often show sensorimotor and cognitive deficits. Therapeutic exercise is the most common treatment strategy for rehabilitating patients with stroke via augmentation of neurogenesis, angiogenesis, neurotrophic factors expression, and synaptogenesis. Neurogenesis plays important roles in sensorimotor and cognitive functional recovery, and can be promoted by exercise; however, the mechanism underlying this phenomenon remains unclear. In this study, we explored the effects of treadmill exercise on sensorimotor and cognitive functional recovery, as well as the potential molecular mechanisms underlying the promotion of neurogenesis in a rat model of transient middle cerebral artery occlusion (tMCAO). We found that treadmill exercise facilitated sensorimotor and cognitive functional recovery after tMCAO, and that neural stem/progenitor cell proliferation, differentiation, and migration were enhanced in the ipsilateral subventricular and subgranular zones after tMCAO. Meanwhile, the newborn neurons induced by treadmill exercise after tMCAO had the similar function with pre-existing neurons. Treadmill exercise significantly increased CD200 and CD200 receptor (CD200R) levels in the ipsilateral hippocampus and cortex. Further study revealed that treadmill exercise-induced neurogenesis and functional recovery were clearly inhibited, while Il-β and Tnf-α expression were upregulated, following lentivirus (LV)-induced suppression of post-stroke CD200R expression. Consistent with the effect of treadmill exercise, CD200Fc (a CD200R agonist) markedly promoted neurogenesis and functional recovery after stroke. In addition, CD200Fc could further enhance the functional recovery induced by treadmill exercise after stroke. Our results demonstrate the beneficial role of treadmill exercise in promoting neurogenesis and functional recovery via activating the CD200/CD200R signaling pathway and improving the inflammatory environment after stroke. Thus, the CD200/CD200R signaling pathway is a potential therapeutic target for functional recovery after stroke.

Ginsenoside F1 promotes angiogenesis by activating the IGF-1/IGF1R pathway

Ischemic stroke is one of the most lethal and highly disabling diseases that seriously affects the human health and quality of life. A therapeutic angiogenic strategy has been proposed to alleviate ischemia-induced injury by promoting angiogenesis and improving cerebrovascular function in the ischemic regions. The insulin-like growth factor 1 (IGF-1)/insulin-like growth factor 1 receptor (IGF1R) axis is crucial for cerebral angiogenesis and neurogenesis. However, effective drugs that prevent cerebral ischemic injury by inducing cerebral angiogenesis via activation of the IGF1R pathway are lacking. Here, we screened a pro-angiogenic agent ginsenoside F1 (GF1), a ginseng saponin isolated from a traditional Chinese medicine that was widely used in ischemic stroke treatment. It promoted the proliferation, mobility and tube formation of human umbilical vein endothelial cells and human brain microvascular endothelial cells, as well as pericytes recruitment to the endothelial tubes. GF1 stimulated vessel sprouting in the rat arterial ring and facilitated neovascularization in chicken embryo chorioallantoic membrane (CAM). In the in vivo experiments, GF1 rescued the axitinib-induced vascular defect in zebrafish. It also increased the microvessel density (MVD) and improved focal cerebral blood perfusion in the rat middle cerebral artery occlusion (MCAO) model. Mechanism studies revealed that GF1-induced angiogenesis depended on IGF1R activation mediated by the autocrine IGF-1 loop in endothelial cells. Based on our findings, GF1-induced activation of the IGF-1/IGF1R pathway to promote angiogenesis is an effective approach to alleviate cerebral ischemia, and GF1 is a potential agent that improves cerebrovascular function and promotes recovery from ischemic stroke.

Prestroke physical activity could influence acute stroke severity (part of PAPSIGOT)

Objective

To investigate the influence of prestroke physical activity (PA) on acute stroke severity.

Methods

Data from patients with first stroke were retrieved from registries with a cross-sectional design. The variables were PA, age, sex, smoking, diabetes, hypertension and statin treatment, stroke severity, myocardial infarction, new stroke during hospital stay, and duration of inpatient care at stroke unit. PA was assessed with Saltin-Grimby's 4-level Physical Activity Level Scale, and stroke severity was assessed with the National Institutes of Health Stroke Scale (NIHSS). Logistic regression was used to predict stroke severity, and negative binomial regression was used to compare the level of PA and stroke severity.

Results

The study included 925 patients with a mean age of 73.1 years, and 45.2% were women. Patients who reported light or moderate PA levels were more likely to present a mild stroke (NIHSS score 0 to 5) compared with physically inactive patients in a model that also included younger age as a predictor (odds ratio = 2.02 for PA and odds ratio = 0.97 for age). The explanatory value was limited at 6.8%. Prestroke PA was associated with less severe stroke, and both light PA such as walking at least 4 h/wk and moderate PA 2–3 h/wk appear to be beneficial. Physical inactivity was associated with increased stroke severity.

Conclusions

This study suggests that PA and younger age could result in a less severe stroke. Both light PA such as walking at least 4 h/wk and moderate PA 2–3 h/wk appear to be beneficial.

Cognitive and structural cerebral changes in amnestic mild cognitive impairment due to Alzheimer's disease after multicomponent training

Introduction

Information about how physical exercise affects patients with amnestic mild cognitive impairment (aMCI) due to Alzheimer's disease (AD) is still missing. This study evaluated the impact of multicomponent exercise training on cognition and brain structure in aMCI subjects with cerebral spinal fluid positive AD biomarkers.

Methods

Forty aMCI subjects were divided in training (multicomponent exercise thrice a week for 6 months) and nontraining groups. Assessments included cardiorespiratory fitness, neurocognitive tests, and a structural magnetic resonance imaging using 3.0 T scanner. FreeSurfer software analyzed hippocampal volume and cortical thickness.

Results

The training group showed increased volume in both hippocampi and better performance in episodic memory test after 6 months. In contrast, the nontraining group declined in functional activities, recognition, and cardiorespiratory fitness for the same period.

Discussion

Multicomponent exercise seems to improve hippocampal volume and episodic memory, and maintains VO_2max in aMCI due to AD.

Determinants of Stroke in Brazil: A Cross-Sectional Multivariate Approach from the National Health Survey

OBJECTIVE

The objective of this study was to investigate the association between biological-health, socioeconomics, and behavioral determinants and stroke by evaluating the risk of stroke in the presence of each or all determinants grouped in a multivariate model.

METHODS

This study is a transversal secondary data analysis of the Brazilian National Health Survey, released by the Brazilian Institute of Geography and Statistics. The prevalence, prevalence ratios, and confidence intervals were calculated for the main outcome. A multivariate regression model was applied, with the stroke as outcome and all other variables with a P value of .20 or lower in the univariate analysis included as explanatory variables to adjust for potential confounders and effect modifiers.

RESULTS

The mean age was 43.3 ± 16.6 years, ranging from 18 to 101 years. The prevalence of hypertension was 21.4%, and with regard to lifestyle habits, it was observed that 20.0% had smoked but stopped and 29.7% practiced physical activity in the last 30 days. The regression model showed that the odds ratio in the final model was weighted, with low schooling, smoking habit, overweight, low physical activity practice, diabetes, and hypertension being significantly associated with stroke.

CONCLUSION

The multivariate model showed that the chance of stroke is high, both combined or isolated.

Stroke

Stroke, or cerebrovascular accident, involves injury to the central nervous system as a result of a vascular cause, and is a leading cause of disability worldwide. People with stroke often experience sensory, cognitive, and motor sequelae that can lead to difficulty walking, controlling balance in standing and voluntary tasks, and reacting to prevent a fall following an unexpected postural perturbation. This chapter discusses the interrelationships between stroke-related impairments, problems with control of balance and gait, fall risk, fear of falling, and participation in daily physical activity. Rehabilitation can improve balance and walking function, and consequently independence and quality of life, for those with stroke. This chapter also describes effective interventions for improving balance and walking function poststroke, and identifies some areas for further research in poststroke rehabilitation.

A Single Bout of High-Intensity Interval Training Improves Motor Skill Retention in Individuals With Stroke

BACKGROUND

One bout of high-intensity cardiovascular exercise performed immediately after practicing a motor skill promotes changes in the neuroplasticity of the motor cortex and facilitates motor learning in nondisabled individuals.

OBJECTIVE

To determine if a bout of exercise performed at high intensity is sufficient to induce neuroplastic changes and improve motor skill retention in patients with chronic stroke.

METHODS

Twenty-two patients with different levels of motor impairment were recruited. On the first session, the effects of a maximal graded exercise test on corticospinal and intracortical excitability were assessed from the affected and unaffected primary motor cortex representational area of a hand muscle with transcranial magnetic stimulation. On the second session, participants were randomly assigned to an exercise or a nonexercise control group. Immediately after practicing a motor task, the exercise group performed 15 minutes of high-intensity interval training while the control group rested. Twenty-four hours after motor practice all participants completed a test of the motor task to assess skill retention.

RESULTS

The graded exercise test reduced interhemispheric imbalances in GABA_A-mediated short-interval intracortical inhibition but changes in other markers of excitability were not statistically significant. The group that performed high-intensity interval training showed a better retention of the motor skill.

CONCLUSIONS

The performance of a maximal graded exercise test triggers only modest neuroplastic changes in patients with chronic stroke. However, a single bout of high-intensity interval training performed immediately after motor practice improves skill retention, which could potentially accelerate motor recovery in these individuals.

High Prestroke Physical Activity Is Associated with Reduced Infarct Growth in Acute Ischemic Stroke Patients Treated with Intravenous tPA and Randomized to Remote Ischemic Perconditioning

BACKGROUND

A high prestroke physical activity (PA) level is associated with reduced stroke rate, stroke mortality, better functional outcome, and possible neuroprotective abilities. The aim of the present study was to examine the possible neuroprotective effect of prestroke PA on 24-h cerebral infarct growth in a cohort of acute ischemic stroke patients treated with intravenous tPA and randomized to remote ischemic perconditioning.

METHODS

In this predefined subanalysis, data from a randomized clinical trial investigating the effect of remote ischemic perconditioning (RIPerC) on AIS was used. Prestroke (7 days before admission) PA was quantified using the PA Scale for the Elderly (PASE) questionnaire at baseline. Infarct growth was evaluated using MRI (acute, 24-h, and 1-month).

RESULTS

PASE scores were obtained from 102 of 153 (67%) patients with a median (interquartile range) age of 66 (58-73) years. A high prestroke PA level correlated significantly with reduced acute infarct growth (24 h) in the linear regression model (4th quartile prestroke PA level compared with the 1st quartile), β4th quartile = -0.82 (95% CI -1.54 to -0.10). However, the effect of prestroke PA was present mainly in patients randomized to RIPerC, β4th quartile = -1.14 (95% CI -2.04 to -0.25). In patients randomized to RIPerC, prestroke PA was a predictor of final infarct size (1-month infarct volume), β4th quartile = -1.78 (95% CI -3.15 to -0.41).

CONCLUSION

In AIS patients treated with RIPerC, as add-on to intravenous thrombolysis, the level of PA the week before the stroke was associated with decreased 24-h infarct growth and final infarct size. These results are highly encouraging and stress the need for further exploration of the potentially protective effects of both PA and remote ischemic conditioning.

Buyang Huanwu decoction facilitates neurorehabilitation through an improvement of synaptic plasticity in cerebral ischemic rats

BACKGROUND

Loss of neural function is a critical but unsolved issue after cerebral ischemia insult. Neuronal plasticity and remodeling are crucial for recovery of neural functions after brain injury. Buyang Huanwu decoction, which is a classic formula in traditional Chinese medicine, can positively alter synaptic plasticity. This study assessed the effects of Buyang Huanwu decoction in combination with physical exercise on neuronal plasticity in cerebral ischemic rats.

METHODS

Cerebral ischemic rats were administered Buyang Huanwu decoction and participated in physical exercise after the induction of a permanent middle cerebral artery occlusion. The neurobehavioral functions and infarct volumes were evaluated. The presynaptic (SYN), postsynaptic (GAP-43) and cytoskeletal (MAP-2) proteins in the coronal brain samples were evaluated by immunohistochemistry and western blot analyses. The ultrastructure of the neuronal synaptic junctions in the same region were analyzed using transmission electron microscopy.

RESULTS

Combination treatment of Buyang Huanwu decoction and physical exercise ameliorated the neurobehavioral deficits (p < 0.05), significantly enhanced the expression levels of SYN, GAP-43 and MAP-2 (p < 0.05), and maintained the synaptic ultrastructure.

CONCLUSIONS

Buyang Huanwu decoction facilitated neurorehabilitation following a cerebral ischemia insult through an improvement in synaptic plasticity. Graphical abstract The Buyang Huanwu decoction (BYHWD) combined with physical exercise (PE) attenuates synaptic disruption and promotes synaptic plasticity following cerebral ischemia (stroke).

MicroRNA-433 Inhibits the Proliferation and Migration of HUVECs and Neurons by Targeting Hypoxia-Inducible Factor 1 Alpha

Emerging evidence has demonstrated an important role of microRNAs (miRNAs) in the pathogenesis of cerebral infarction. In the present study, a down-regulation of microRNA-433 (miR-433) is identified in hypoxia-induced human umbilical vein vascular endothelial cells (HUVECs) as well as in rat neurons, and is found to be negatively regulated cell proliferation and migration. Moreover, the expression of miR-433 is inversely correlated with the expression of hypoxia-inducible factor 1 alpha (HIF-1α), which has been shown to play critical role in responding to hypoxia conditions. Overexpression or knockdown of miR-433 responsively alters both mRNA and protein levels of HIF-1α and its downstream genes, vascular endothelial growth factor, Glut-1, and Angpt2. In a luciferase reporter system, miR-433 down-regulates the luciferase activity of HIF-1α 3'-UTR, and these effects are abolished by a mutation in the putative miR-433-binding site. Further investigation confirms that knockdown of HIF-1α blocked the stimulatory effect of anti-miR-433, while overexpression of HIF-1α reversed the inhibitory effects of pre-miR-433 on proliferation and migration of HUVEC and neurons. Taken together, our findings indicate that miR-433 plays an important role in response to hypoxia, inhibiting HUVEC and neuron proliferation and migration by down-regulating HIF-1α.

Exercise and cerebrovascular plasticity

Aging impairs cerebrovascular plasticity and subsequently leads cerebral hypoperfusion, which synergistically accelerates aging-associated cognitive dysfunction and neurodegenerative diseases associated with impaired neuronal plasticity. On the other hand, over two decades of researches have successfully demonstrated that exercise, or higher level of physical activity, is a powerful and nonpharmacological approach to improve brain function. Most of the studies have focused on the neuronal aspects and found that exercise triggers improvements in neuronal plasticity, such as neurogenesis; however, exercise can improve cerebrovascular plasticity as well. In this chapter, to understand these beneficial effects of exercise on the cerebral vasculature, we first discuss the issue of changes in cerebral blood flow and its regulation during acute bouts of exercise. Then, how regular exercise improves cerebrovascular plasticity will be discussed. In addition, to shed light on the importance of understanding interactions between the neuron and cerebral vasculature, we describe neuronal activity-driven uptake of circulating IGF-I into the brain.

Long-Term Exercise Improves Memory Deficits via Restoration of Myelin and Microvessel Damage, and Enhancement of Neurogenesis in the Aged Gerbil Hippocampus After Ischemic Stroke

BACKGROUND

The positive correlation between therapeutic exercise and memory recovery in cases of ischemia has been extensively studied; however, long-term exercise begun after ischemic neuronal death as a chronic neurorestorative strategy has not yet been thoroughly examined.

OBJECTIVE

The purpose of this study is to investigate possible mechanisms by which exercise ameliorates ischemia-induced memory impairment in the aged gerbil hippocampus after transient cerebral ischemia.

METHODS

Treadmill exercise was begun 5 days after ischemia-reperfusion (I-R) and lasted for 1 or 4 weeks. The animals were sacrificed 31 days after the induction of ischemia. Changes in short-term memory, as well as the hippocampal expression of markers of cell proliferation, neuroblast differentiation, neurogenesis, myelin and microvessel repair, and growth factors were examined by immunohistochemistry and/or western blots.

RESULTS

Four weeks of exercise facilitated memory recovery despite neuronal damage in the stratum pyramidale (SP) of the hippocampal CA1 region and in the polymorphic layer (PoL) of the dentate gyrus (DG) after I-R. Long-term exercise enhanced cell proliferation and neuroblast differentiation in a time-dependent manner, and newly generated mature cells were found in the granule cell layer of the DG, but not in the SP of the CA1 region or in the PoL of the DG. In addition, long-term exercise ameliorated ischemia-induced damage of myelin and microvessels, which was correlated with increased BDNF expression in the CA1 region and the DG.

CONCLUSIONS

These results suggest that long-term treadmill exercise after I-R can restore memory function through replacement of multiple damaged structures in the ischemic aged hippocampus.

Physical Activity and Exercise as a Basic Preventive Measure (Primary Prevention, Prevention after Renal Transplantation)

Movement is an inseparable part of one's life, and has been a basic everyday activity through the history of mankind. However, a lack of physical activity and availability of food have resulted in a variety of serious health impairments. The 20th century has witnessed a steep rise of mortality from cardiovascular disease, increase in the prevalence of type-2 diabetes mellitus, malignant diseases, and dramatic increase in body weight initially in industrialized nations followed, in the last two decades of the last century, by the populations of third-world countries with all inherent consequences of this phenomenon. Preventive programmes involving physical activity have also been on the list of top priorities of various materials issued by the World Health Organization. Physical activity is one of the simplest non-pharmacological tools in the prevention of a plethora of diseases. The simplest physical activity, even for therapeutic purposes, is walking. We can walk any time, virtually anywhere, so walking is also the least expensive therapeutic option.

Improved Cardiorespiratory Fitness Is Associated with Increased Cortical Thickness in Mild Cognitive Impairment

Cortical atrophy is a biomarker of Alzheimer's disease (AD) that correlates with clinical symptoms. This study examined changes in cortical thickness from before to after an exercise intervention in mild cognitive impairment (MCI) and healthy elders. Thirty physically inactive older adults (14 MCI, 16 healthy controls) underwent MRI before and after participating in a 12-week moderate intensity walking intervention. Participants were between the ages of 61 and 88. Change in cardiorespiratory fitness was assessed using residualized scores of the peak rate of oxygen consumption (V̇O2peak) from pre- to post-intervention. Structural magnetic resonance images were processed using FreeSurfer v5.1.0. V̇O2peak increased an average of 8.49%, which was comparable between MCI and healthy elders. Overall, cortical thickness was stable except for a significant decrease in the right fusiform gyrus in both groups. However, improvement in cardiorespiratory fitness due to the intervention (V̇O2peak) was positively correlated with cortical thickness change in the bilateral insula, precentral gyri, precuneus, posterior cingulate, and inferior and superior frontal cortices. Moreover, MCI participants exhibited stronger positive correlations compared to healthy elders in the left insula and superior temporal gyrus. A 12-week moderate intensity walking intervention led to significantly improved fitness in both MCI and healthy elders. Improved V̇O2peak was associated with widespread increased cortical thickness, which was similar between MCI and healthy elders. Thus, regular exercise may be an especially beneficial intervention to counteract cortical atrophy in all risk groups, and may provide protection against future cognitive decline in both healthy elders and MCI.

Lost in translation: rethinking approaches to stroke recovery

Stroke is the second leading cause of death and the preeminent cause of neurological disability. Attempts to limit brain injury after ischemic stroke with clot-dissolving drugs have met with great success but their use remains limited due to a narrow therapeutic time window and concern over serious side effects. Unfortunately, the neuroprotective strategy failed in clinical trials. A more promising approach is to promote recovery of function in people affected by stroke. Following stroke, there is a heightened critical period of plasticity that appears to be receptive to exogenous interventions (e.g., delivery of growth factors) designed to enhance neuroplasticity processes important for recovery. An emerging concept is that combinational therapies appear much more effective than single interventions in improving stroke recovery. One of the most promising interventions, with clinical feasibility, is enriched rehabilitation, a combination of environmental enrichment and task-specific therapy.

Physical activity and risk of cardiovascular disease: what does the new epidemiological evidence show?

PURPOSE OF REVIEW

Abundant evidence has documented inverse associations of physical activity and the risk of cardiovascular disease (CVD). However, the effects of different types of physical activity (e.g., leisure time and occupational physical activity) are still poorly understood.

RECENT FINDINGS

Drawing on recommended and established guidelines for study selection, we identified and included 23 prospective epidemiological studies published during the last 2 years. These studies included a total of more than 790 000 adults at baseline with some 22 000 incident cases occurring during follow-up. Our findings suggest that moderate and high levels of leisure time physical activity are associated with a moderately reduced risk of CVD. In contrast, moderate and high levels of occupational physical activity showed weak positive associations, that is, a slightly increased risk of CVD.

SUMMARY

This updated meta-analysis supports the notion of primary prevention of CVD through engagement in leisure time physical activity. The role of occupational physical activity in CVD prevention is questionable.

Impact of a single bout of aerobic exercise on regional brain perfusion and activation responses in healthy young adults

Purpose

Despite the generally accepted view that aerobic exercise can have positive effects on brain health, few studies have measured brain responses to exercise over a short time span. The purpose of this study was to examine the impact within one hour of a single bout of exercise on brain perfusion and neuronal activation.

Methods

Healthy adults (n = 16; age range: 20–35 yrs) were scanned using Magnetic Resonance Imaging (MRI) before and after 20 minutes of exercise at 70% of their age-predicted maximal heart rate. Pseudo-continuous arterial spin labeling (pcASL) was used to measure absolute cerebral blood flow (CBF) prior to exercise (pre) and at 10 min (post-10) and 40 min (post-40) post-exercise. Blood oxygenation level dependent (BOLD) functional MRI (fMRI) was performed pre and post-exercise to characterize activation differences related to a go/no-go reaction time task.

Results

Compared to pre-exercise levels, grey matter CBF was 11% (±9%) lower at post-10 (P<0.0004) and not different at post-40 (P = 0.12), while global WM CBF was increased at both time points post-exercise (P<0.0006). Regionally, the hippocampus and insula showed a decrease in perfusion in ROI-analysis at post-10 (P<0.005, FDR corrected), whereas voxel-wise analysis identified elevated perfusion in the left medial postcentral gyrus at post-40 compared to pre (p_corrected = 0.05). BOLD activations were consistent between sessions, however, the left parietal operculum showed reduced BOLD activation after exercise.

Conclusion

This study provides preliminary evidence of regionalized brain effects associated with a single bout of aerobic exercise. The observed acute cerebrovascular responses may provide some insight into the brain’s ability to change in relation to chronic interventions.

Physical activity and gastric cancer: so what? An epidemiologist's confession

Epidemiologists, like many scientists, tend to become specialized and focused on a particular disease, even though behavioral risk factors such as physical activity have effects across many diseases. This commentary is a personal reflection by an epidemiologist on the shortcomings of this disease-oriented approach to prevention.