Severity of Vitamin D Deficiency Predicts Mortality in Ischemic Stroke Patients

Diet and Nutraceuticals for treatment and prevention of primary and secondary stroke: Emphasis on nutritional antiplatelet and antithrombotic agents

Ischemic stroke is a devastating disease that causes morbidity and mortality. Malnutrition following ischemic stroke is common in stroke patients. During the rehabilitation, the death rates of stroke patients are significantly increased due to malnutrition. Nutritional supplements such as protein, vitamins, fish, fish oils, moderate wine or alcohol consumption, nuts, minerals, herbal products, food colorants, marine products, fiber, probiotics and Mediterranean diets have improved neurological functions in stroke patients as well as their quality of life. Platelets and their mediators contribute to the development of clots leading to stroke. Ischemic stroke patients are treated with thrombolytics, antiplatelets, and antithrombotic agents. Several systematic reviews, meta-analyses, and clinical trials recommended that consumption of these nutrients and diets mitigated the vascular, peripheral, and central complications associated with ischemic stroke (Fig. 2). Particularly, these nutraceuticals mitigated the platelet adhesion, activation, and aggregation that intended to reduce the risks of primary and secondary stroke. Although these nutraceuticals mitigate platelet dysfunction, there is a greater risk of bleeding if consumed excessively. Moreover, malnutrition must be evaluated and adequate amounts of nutrients must be provided to stroke patients during intensive care units and rehabilitation periods. In this review, we have summarized the importance of diet and nutraceuticals in ameliorating neurological complications and platelet dysfunction with an emphasis on primary and secondary prevention of ischemic stroke.

Selected serum cytokines and vitamin D levels as potential prognostic markers of acute ischemic stroke

Inflammation-derived oxidative stress is postulated to contribute to neuronal damage leading to poor clinical outcomes in Acute Ischemic Stroke (AIS). We aimed to investigate the association between serum levels of selected cytokines (IL-1β, IFN-γ, IL-4), and vitamin D in ischemic stroke progression, and their accuracy in predicting AIS prognosis, among Sri Lankans. We compared 60 AIS patients admitted in 4 phases post-stroke onset (<6 h; 6-24 h; 24-48 h; 48-96 h; n = 15/phase), with 15 age- and sex-matched controls. The 30-day functional outcome (FO) was assessed using the modified Rankin Scale (mRS). Serum cytokine and vitamin D levels were quantified using sandwich ELISAs, and competitive ELISA, respectively. The CombiROC web tool established optimal prognostic biomarker combinations. Serum IL-1β and IFN-γ were elevated in all four phases following stroke onset while IL-4 was elevated exclusively in the recovery phase (48-96 h) (p<0.05). Th1 bias polarization of the Th1:Th2 cytokine (IFN-γ:IL-4) ratio occurred with AIS progression while a Th2 bias occurred during AIS recovery (p<0.05). Lower serum IL-1β and higher IL-4 levels were associated with a good FO (p<0.05), while lower Vitamin D levels were related to a poor FO (p = 0.001). The triple-biomarker panel, IL-4- IFN-γ -Vit D, accurately predicted AIS prognosis (sensitivity = 100%, specificity = 91.9%, area under the curve = 0.98). Serum immunologic mediators IFN-γ, IL-4, and vitamin D may be useful biomarkers of AIS prognosis and may serve as therapeutic targets in improving stroke outcomes. Vitamin D supplementation may improve the prognosis of AIS patients. Furthermore, binary logistic model fitted for FO indicated Th1:Th2 cytokine ratio (IFN-γ:IL-4), vitamin D status, history of stroke, and ischemic heart disease as significant predictors of AIS prognosis.

Role of vitamin D in the association between pre-stroke sleep quality and poststroke depression and anxiety

PURPOSE

Poor sleep quality, mood disorders, and vitamin D deficiency are common in stroke. We investigated the association between serum vitamin D levels and pre-stroke sleep quality and the occurrence of poststroke depression (PSD) and poststroke anxiety (PSA) in acute ischemic stroke (AIS).

METHODS

This prospective cross-sectional study included hospitalized patients with AIS and age- and sex-matched controls. Vitamin D levels were measured within 24 h of admission. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) at admission. The severity of depression and anxiety symptoms was evaluated according to Beck Depression Inventory and Beck Anxiety Inventory scores, respectively, within 72 h after admission.

RESULTS

Comparing 214 AIS patients with 103 controls, patients had significantly higher scores of Beck Depression Inventory, Beck Anxiety Inventory, and PSQI and lower vitamin D levels (p < 0.001). Among AIS patients, Beck Depression Inventory (p = 0.004) and Beck Anxiety Inventory (p = 0.018) scores were significantly higher in bad sleepers (PSQI score ≥ 6) than in good sleepers (PSQI score ≤ 5). Correlation analysis revealed negative correlations between serum vitamin D levels and Beck Depression Inventory (r =  - 0.234; p < 0.001), Beck Anxiety Inventory (r =  - 0.135; p = 0.016), and PSQI (r =  - 0.218; p < 0.001) scores.

CONCLUSION

Decreased serum vitamin D levels at admission are associated with a high risk for PSD and PSA in patients with poor pre-stroke sleep quality during the early stages of AIS.

Association between Vitamin D and Short-Term Functional Outcomes in Acute Ischemic Stroke

Vitamin D (Vit D) affects musculoskeletal performance and central nervous system neuroprotection. We aimed to investigate the association between serum Vit D levels and short-term functional outcomes in patients with acute ischemic stroke. This study involved patients with acute ischemic stroke confirmed on brain MRI. The National Institutes of Health Stroke Scale (NIHSS) was used to assess initial stroke severity upon admission. We evaluated the functional outcomes using the Berg Balance Scale (BBS), Manual Function Test (MFT), Korean Mini-Mental State Examination (K-MMSE), Korean version of the modified Barthel Index (K-MBI) within three weeks from the onset of stroke, and modified Rankin Scale (mRS) score at discharge. Overall, 192 patients were finally included and divided into three groups: Vit D sufficient (n = 28), insufficient (n = 49), and deficient (n = 115). Multivariate analysis showed that the Vit D deficient group presented with a higher risk of initially severe stroke (p = 0.025) and poor functional outcomes on the BBS (p = 0.048), MFT (p = 0.017), K-MMSE (p = 0.001), K-MBI (p = 0.003), and mRS (p = 0.032) compared to the Vit D sufficient group. Vit D deficiency may be associated with severe initial stroke and poor short-term post-stroke functional outcomes.

Novel Insights into the Molecular Mechanisms of Atherosclerosis

Atherosclerosis is one of the most fatal diseases in the world. The associated thickening of the arterial wall and its background and consequences make it a very composite disease entity with many mechanisms that lead to its creation. It is an active process, and scientists from various branches are engaged in research, including molecular biologists, cardiologists, and immunologists. This review summarizes the available information on the pathophysiological implications of atherosclerosis, focusing on endothelium dysfunction, inflammatory factors, aging, and uric acid, vitamin D, and miRNA expression as recent evidence of interactions of the molecular and cellular elements. Analyzing new discoveries for the underlying causes of this condition assists the general research to improve understanding of the mechanism of pathophysiology and thus prevention of cardiovascular diseases.

Association of Long Non-Coding RNA Malat1 with Serum Levels of Interleukin-1 Beta and Vitamin D in Patients with Ischemic Stroke

BACKGROUND

Previous studies have demonstrated the strong association of inflammatory cytokines and vitamin D (VitD) deficiency and ischemic stroke (IS) pathogenesis. Due to the negative correlation between long non-coding RNA (lncRNA) Malat1 and pro-inflammatory factors we decided to investigate the associations between Malat1 expression with serum interleukin-1β (IL-1β), and VitD levels in IS patients.

MATERIALS AND METHODS

In this cross-sectional study, 63 IS patients were included. We used enzyme-linked immunosorbent assays to evaluate the serum levels of VitD and IL-1β. Malat1 expression was evaluated by the real-time polymerase chain reaction test. The associations between Malat1expression with VitD and IL-1β were analysed with linear regression (Stepwise model) and Pearson's correlation analysis.

RESULTS

The Malat1 expression was inversely correlated with stroke severity (r=-0.25, P=0.043). Stepwise regression analysis showed a significant positive relationship between VitD level and Malat1 expression (Beta=0.28, P=0.02), and also showed a non-significant negative relationship between IL-1β and stroke severity. VitD level showed a positive Pearson correlation with Malat1 (r=0.28, P=0.023) and a negative correlation with IL-1β (r=-0.29, P=0.018) while it could not detect a significantly negative correlation with stroke severity.

CONCLUSION

For the first time the associations between Malat1 expression with IL-1β and VitD in IS patients was analyzed. We found a significant positive relationship between VitD and Malat1. This correlation needs to be investigated with a larger sample size to achieve a strong and reliable association between VitD and Malat1.

Is Vitamin D Deficiency Prothrombotic? A Systematic Review

Observational studies indicate a relationship between vitamin D deficiency and an increased risk of venous and arterial thrombotic events, but the underlying mechanisms behind this association are uncertain. This systematic review explores if there is an association between decreased vitamin D levels and a prothrombotic profile. The systematic literature search initially identified 3,214 studies (published until December 21, 2021) investigating the relationship between vitamin D and numerous hemostatic parameters. After the screening process, 18 observational and intervention studies fulfilled the inclusion criteria and were included in this systematic review. Parameters of primary hemostasis, secondary hemostasis, and fibrinolysis were investigated in six, thirteen, and fifteen of these studies, respectively. Most of the eligible studies did not identify significant associations between decreased vitamin D levels and hemostatic parameters. Some conflicting results were found between decreased vitamin D levels and thrombin generation parameters and the tissue factor pathway inhibitor. Conflicting results were also found between decreased vitamin D levels and fibrinolytic parameters, although the evidence may point toward weak associations with some regulators of fibrinolysis, mostly decreased tissue type plasminogen activator. Overall, our systematic review did not identify any definitive link between vitamin D deficiency and a prothrombotic profile, which might otherwise help explain the observed association between vitamin D deficiency and increased risk of thrombotic events. Moreover, there is no clinical evidence to confirm or refute a possible antithrombotic effect of vitamin D. Larger high-quality randomized controlled trials are needed to better elucidate the link between vitamin D deficiency and a prothrombotic risk profile.

Vitamin D serum level predicts stroke clinical severity, functional independence, and disability—A retrospective cohort study

Background

Stroke is a leading cause of mortality and disability and one of the most common neurological conditions globally. Many studies focused on vitamin D as a stroke risk factor, but only a few focused on its serum level as a predictor of stroke initial clinical severity and recovery with inconsistent results. The purpose of this study was to assess the relationship between serum vitamin D levels and stroke clinical severity at admission and functional independence and disability at discharge in Saudi Arabia.

Methodology

A retrospective cohort study of adult ischemic stroke patients who had their vitamin D tested and admitted within 7 days of exhibiting stroke symptoms at King Abdulaziz Medical City (KAMC) Jeddah, Saudi Arabia. Based on vitamin D level, the patients were categorized into normal [25(OH)D serum level ≥ 75 nmol/L], insufficient [25(OH)D serum level is 50–75 nmol/L], and deficient [25(OH)D serum level ≤ 50 nmol/L]. The primary outcome was to assess the vitamin D serum level of ischemic stroke patients’ clinical severity at admission and functional independence at discharge. The National Institute of Health Stroke Scale (NIHSS) was used to assess the clinical severity, whereas the modified Rankin scale (mRS) was used to assess functional independence and disability.

Results

The study included 294 stroke patients, out of 774, who were selected based on the inclusion and exclusion criteria. The mean age of the participants was 68.2 ± 13.4 years, and 49.3% were male. The patients’ distribution among the three groups based on their vitamin D levels is: normal (n = 35, 11.9%), insufficient (n = 66, 22.5%), and deficient (n = 196, 65.6%). After adjusting for potential covariates, regression analysis found a significant inverse relationship of NIHSS based on 25(OH)D serum level (beta coefficient: −0.04, SE: 0.01, p = 0.003). Patients with deficient serum vitamin D level also had significantly higher odds of worse functional independence in mRS score [OR: 2.41, 95%CI: (1.13–5.16), p = 0.023] when compared to participants with normal vitamin D level.

Conclusion

Low vitamin D levels were associated with higher severity of stroke at admission and poor functional independence and disability at discharge in patients with acute ischemic stroke. Further randomized clinical and interventional studies are required to confirm our findings.

Genetically-Proxied Levels of Vitamin D and Risk of Intracerebral Hemorrhage

Background The evidence linking vitamin D (VitD) levels and spontaneous intracerebral hemorrhage (ICH) remains inconclusive. We tested the hypothesis that lower genetically determined VitD levels are associated with higher risk of ICH. Methods and Results We conducted a 2 sample Mendelian Randomization (MR) study using publicly available summary statistics from published genome-wide association studies of VitD levels (417 580 study participants) and ICH (1545 ICH cases and 1481 matched controls). We used the inverse-variance weighted approach to generate causal estimates and the MR Pleiotropy Residual Sum and Outlier and MR-Egger approaches to assess for horizontal pleiotropy. To account for known differences in their underlying mechanism, we implemented stratified analysis based on the location of the hemorrhage within the brain (lobar or nonlobar). Our primary analysis indicated that each SD decrease in genetically instrumented VitD levels was associated with a 60% increased risk of ICH (odds ratio [OR], 1.60; [95% CI, 1.05-2.43]; P=0.029). We found no evidence of horizontal pleiotropy (MR-Egger intercept and MR Pleiotropy Residual Sum and Outlier global test with P>0.05). Stratified analyses indicated that the association was stronger for nonlobar ICH (OR, 1.87; [95% CI, 1.18-2.97]; P=0.007) compared with lobar ICH (OR, 1.43; [95% CI, 0.86-2.38]; P=0.17). Conclusions Lower levels of genetically proxied VitD levels are associated with higher ICH risk. These results provide evidence for a causal role of VitD metabolism in ICH.

The Role of Vitamin D in Stroke Prevention and the Effects of Its Supplementation for Post-Stroke Rehabilitation: A Narrative Review

Hypovitaminosis D is a serious public health problem, representing an independent factor in mortality among the general population. Vitamin D deficiency may affect up to one billion people worldwide. Recently, the potential association between vitamin D levels and stroke has gained increasing attention. Many studies suggest that maintaining normal serum vitamin D levels is associated with improvement of the cardiovascular system and a reduction in stroke risk. As a neurosteroid, vitamin D influences brain development and function and immunomodulation and affects brain neuroplasticity. It supports many processes that maintain homeostasis in the body. As stroke is the second most common cause of death worldwide, more studies are needed to confirm the positive effects of vitamin D supplementation, its dosage at different stages of the disease, method of determination, and effect on stroke onset and recovery. Many studies on stroke survivors indicate that serum vitamin D levels only offer insignificant benefits and are not beneficial to recovery. This review article aims to highlight recent publications that have examined the potential of vitamin D supplementation to improve rehabilitation outcomes in stroke survivors. Particular attention has been paid to stroke prevention.

The Evaluation of the Neuroprotective Effect of a Single High-Dose Vitamin D3 in Patients with Moderate Ischemic Stroke

INTRODUCTION

Vitamin D insufficiency is highly prevalent and is a negative predictor for survival in ischemic stroke patients. We evaluated the effect of a high dose of vitamin D3 on the Neuron-Specific Enolase (NSE) level, National Institute of Health Stroke Scale (NIHSS), and Barthel Index (BI) scoring system in moderate ischemic stroke patients.

METHODS

This prospective, double-blind, randomized clinical trial (RCT) study was conducted from April 2020 to March 2021. Patients with moderate ischemic stroke (NIHSS 5 to 15) who had vitamin D deficiency (serum 25-OH vitamin D ≤30 ng/mL) were recruited and randomized into intervention and control groups. Subjects in the intervention group received a single dose, intramuscular (IM) injection of 600000 international unit (IU) vitamin D3, in addition to the standard treatment. NSE level and NIHSS were evaluated at baseline and 48 hours after the intervention. The BI was monitored three months after discharge.

RESULTS

During the study period, 570 patients were assessed; finally, forty-one patients completed the study. Except for the age which was higher in the control group (p = 0.04), there were no statistically significant differences in other baseline characteristics between the two groups. After 48 hours, the NIHSS score was significantly lower in the intervention group (median 8 vs. 6.5, p = 0.008 in the control and intervention groups, respectively), but there was no significant difference in the NSE level (p = 0.80). Three months after discharge, the BI was significantly higher in the intervention group (median 8 vs. 9, p = 0.03 in the control and intervention groups, respectively).

CONCLUSIONS

Administration of a single 600000 IU of vitamin D3 could have neuroprotective effects in patients with moderate ischemic stroke, according to its significantly positive effects on functional clinical outcomes (NIHSS and BI), but this effect on the biomarker related to neural damage (NSE) was not significant.

Circulating 25-hydroxy-vitamin D and the risk of cardiovascular diseases. Systematic review and meta-analysis of prospective cohort studies

AIMS

Circulating vitamin D is linked with the risk of cardiovascular disease (CVD). A meta-analysis has yet to explicitly explore correlation between vitamin D and the risk of CVD incidence and recurrent CVD. This meta-analysis examines the association between 25-hydroxy-vitamin D (25(OH)D) and the risk of CVD incidence (fatal, non-fatal, fatal and non-fatal combined events) and the risk of recurrent CVD (fatal, recurrent, and fatal and recurrent combined events). PROSPERO registration-CRD42021251483.

DATA SYNTHESIS

A total of 79 studies (46 713 CVD cases in 1 397 831 participants) were included in the meta-analysis, of which 61 studies examined the risk of CVD incidence events, and 18 studies examined risk of recurrent CVD events. The risk of CVD incidence events (RR = 1.34, 95% CI: 1.26-1.43, p < 0.001) and recurrent CVD events (RR = 1.86, 95% CI: 1.46-2.36, p < 0.001) was higher in the lowest than the highest category of circulating 25(OH)D. Dose-response analysis reported a linear association for every 10 ng/ml increment of 25(OH)D and non-fatal CVD incidence events (RR = 0.94; 95% CI = 0.89-0.98, p = 0.005), lower fatal recurrent CVD events (RR = 0.45; 95% CI = 0.32-0.62, p < 0.001) and lower combined recurrent CVD events (RR = 0.80; 95% CI = 0.65-0.97, p = 0.023). A non-linear association was observed between higher 25(OH)D and lower fatal CVD incidence events (P-nonlinear<0.001), lower combined CVD incidence events (P-nonlinear = 0.001), and lower non-fatal recurrent CVD events (P-nonlinear = 0.044).

CONCLUSIONS

The lowest category of circulating 25(OH)D was associated with a higher risk of CVD incidence events and recurrent CVD events.

Italian Public Health Expenditure for Vitamin D is still high: New Outlook to Saving From a Consumption Analysis in the Liguria Region

PURPOSE

Italian expenditure for vitamin D greatly increased in the last few years, reaching €314 million ($376.8 million) in 2019. In Italy, the main cause of the increase in public spending for vitamin D is the marketing of high-cost medicines. At national and regional levels, some interventions have been performed to reduce expenditure, but spending has continued to increase. The aim of this work is to propose a new saving strategy determined by an analysis of a significant sample of the market.

METHODS

Data on the use of vitamin D formulations, including data for the different active substances that represent its pharmaceutical analogue and composition of groups of equivalence, were extrapolated from the Italian Medicines Agency transparency lists and from the Farmadati database. Data on pharmaceutical expenditure were obtained from the Data Warehouse of Liguria Region; the composition of this expenditure was analyzed in detail, focusing on the characteristics of the pharmaceutical preparations and their cost (price per defined daily dose).

FINDINGS

Vitamin D expenditure paralleled that of cholecalciferol, the most used active ingredient, which in Liguria increased from €643,352 ($772,022.4) in 2010 to €8,006,574 ($9,607,888.8) in 2019 (increase of 1144%). Spending focused on high-cost formulations, exceeding 90% of total cholecalciferol cost in 2019. We simulated a possible optimization of the expense for cholecalciferol by applying a revised price to all the cholecalciferol consumptions in high-cost products because these formulations do not have an added therapeutic value, finding that the saving would be at least 60%. National data on the detailed expenditure composition for vitamin D are not available, but we found a strong resemblance between total cholecalciferol expenditure time series in Italy and the Liguria Region.

IMPLICATIONS

The expense of cholecalciferol and consequently the expense of vitamin D could be optimized by modifying the reimbursement of high-cost formulations. At a national level, savings should be proportional to that estimated for the Liguria Region. On the basis of the 2019 data, Italian savings with respect to total cholecalciferol expenditure should be €170.65 million ($204.78 million); per capita cholecalciferol expenditure would shift from €4.66 ($5.59) to €1.84 ($2.21).

Low vitamin D levels and the long-term functional outcome of stroke up to 5 years

BACKGROUND AND PURPOSE

Previous studies have established that vitamin D was associated with stroke. The purpose of this study was to investigate the relationship between vitamin D and 5-year outcome of patients with stroke including acute ischemic stroke (AIS) and intracranial hemorrhage (ICH) stroke.

METHODS

Serum 25-hydroxyvitamin D levels were prospectively analyzed in patients admitted to the First Affiliated Hospital of Wenzhou Medical University from 2013 to 2015. Modified Rankin scale (mRS) was used to evaluate their 5-year functional outcome, and univariate and multivariate logistic regressions were applied to evaluate the effects of vitamin D on stroke outcome.

RESULTS

In total, 668 patients diagnosed with stroke were recruited, and 420 completed the 5-year follow-up. Ninety-five patients experienced poor outcome in the 5 years since stroke onset. Vitamin D levels in patients with poor outcome showed significant differences compared to good outcome patients (p < .001). In multivariable logistic regression analysis, after adjusting the potential confounders, the 5-year functional outcome was significantly associated with vitamin D levels. Stroke patients with vitamin D levels less than 38.4 nmol/L had a higher risk for poor outcome compared with those with vitamin D level over 71.4 nmol/L at 5-year (odds ratio [OR] = 3.66, 95% confidence interval [CI] = 1.42-9.45, p = .007), which was consistent with AIS patients (OR = 6.36, 95% CI = 1.89-21.44, p = .003).

CONCLUSION

Vitamin D level less than 38.4 nmol/L at admission is a potential risk biomarker for poor functional outcome at 5-year prognosis in AIS patients, which might provide new ideas for the prognostic assessment of stroke.

Double-Edged Sword of Vitamin D3 Effects on Primary Neuronal Cultures in Hypoxic States

The use of vitamin D3 along with traditional therapy opens up new prospects for increasing the adaptive capacity of nerve cells to the effects of a wide range of stress factors, including hypoxia-ischemic processes. However, questions about prophylactic and therapeutic doses of vitamin D3 remain controversial. The purpose of our study was to analyze the effects of vitamin D3 at different concentrations on morpho-functional characteristics of neuron-glial networks in hypoxia modeling in vitro. We showed that a single administration of vitamin D3 at a high concentration (1 µM) in a normal state has no significant effect on the cell viability of primary neuronal cultures; however, it has a pronounced modulatory effect on the functional calcium activity of neuron-glial networks and causes destruction of the network response. Under hypoxia, the use of vitamin D3 (1 µM) leads to total cell death of primary neuronal cultures and complete negation of functional neural network activity. In contrast, application of lower concentrations of vitamin D3 (0.01 µM and 0.1 µM) caused a pronounced dose-dependent neuroprotective effect during the studied post-hypoxic period. While the use of vitamin D3 at a concentration of 0.1 µM maintained cell viability, preventive administration of 0.01 µM not only partially preserved the morphological integrity of primary neuronal cells but also maintained the functional structure and activity of neuron-glial networks in cultures. Possible molecular mechanisms of neuroprotective action of vitamin D3 can be associated with the increased expression level of transcription factor HIF-1α and maintaining the relationship between the levels of BDNF and TrkB expression in cells of primary neuronal cultures.

Intestinal Barrier Dysfunction Participates in the Pathophysiology of Ischemic Stroke

The gastrointestinal tract is a major organ for the body to absorb nutrients, water and electrolytes. At the same time, it is a tight barrier to resist the invasion of harmful substances and maintain the homeostasis of the internal environment. Destruction of the intestinal barrier is linked to the digestive system, cardiovascular system, endocrine system and other systemic diseases. Mounting evidence suggests that ischemic stroke not only changes the intestinal microbes, but also increases the permeability of the intestinal barrier, leading to bacterial translocation, infection, and even sepsis. The intestinal barrier, as part of the gut-brain axis, has also been proven to participate in the pathophysiological process of ischemic stroke. However, little attention has been paid to it. Since ischemic stroke is a major public health issue worldwide, there is an urgent need to know more about the disease for better prevention, treatment and prognosis. Therefore, understanding the pathophysiological relationship between ischemic stroke and the intestinal barrier will help researchers further uncover the pathophysiological mechanism of ischemic stroke and provide a novel therapeutic target for the treatment of ischemic stroke. Here, we review the physiology and pathology between ischemic stroke and intestinal barrier based on related articles published in the past ten years about the relationship between ischemic stroke, stroke risk factors and intestinal flora, intestinal barrier, and discuss the following parts: the intestinal barrier; possible mechanisms of intestinal barrier destruction in ischemic stroke; intestinal barrier destruction caused by stroke-related risk factors; intestinal barrier dysfunction in ischemic stroke; targeting the intestinal barrier to improve stroke; conclusions and perspectives.

Palmatine Protects against Cerebral Ischemia/Reperfusion Injury by Activation of the AMPK/Nrf2 Pathway

Palmatine (PAL), a natural isoquinoline alkaloid, possesses extensive biological and pharmaceutical activities, including antioxidative stress, anti-inflammatory, antitumor, neuroprotective, and gastroprotective activities. However, it is unknown whether PAL has a protective effect against ischemic stroke and cerebral ischemia/reperfusion (I/R) injury. In the present study, a transient middle cerebral artery occlusion (MCAO) mouse model was used to mimic ischemic stroke and cerebral I/R injury in mice. Our study demonstrated that PAL treatment ameliorated cerebral I/R injury by decreasing infarct volume, neurological scores, and brain water content. PAL administration attenuated oxidative stress, the inflammatory response, and neuronal apoptosis in mice after cerebral I/R injury. In addition, PAL treatment also decreases hypoxia and reperfusion- (H/R-) induced neuronal injury by reducing oxidative stress, the inflammatory response, and neuronal apoptosis. Moreover, the neuroprotective effects of PAL were associated with the activation of the AMP-activated protein kinase (AMPK)/nuclear factor E2-related factor 2 (Nrf2) pathway, and Nrf2 knockdown offsets PAL-mediated antioxidative stress and anti-inflammatory effects. Therefore, our results suggest that PAL may be a novel treatment strategy for ischemic stroke and cerebral I/R injury.

Vitamin D and Its Role in the Lipid Metabolism and the Development of Atherosclerosis

Vitamin D, a crucial hormone in the homeostasis and metabolism of calcium bone, has lately been found to produce effects on other physiological and pathological processes genomically and non-genomically, including the cardiovascular system. While lower baseline vitamin D levels have been correlated with atherogenic blood lipid profiles, 25(OH)D supplementation influences the levels of serum lipids in that it lowers the levels of total cholesterol, triglycerides, and LDL-cholesterol and increases the levels of HDL-cholesterol, all of which are known risk factors for cardiovascular disease. Vitamin D is also involved in the development of atherosclerosis at the site of the blood vessels. Deficiency of this vitamin has been found to increase adhesion molecules or endothelial activation and, at the same time, supplementation is linked to the lowering presence of adhesion surrogates. Vitamin D can also influence the vascular tone by increasing endothelial nitric oxide production, as seen in supplementation studies. Deficiency can lead, at the same time, to oxidative stress and an increase in inflammation as well as the expression of particular immune cells that play a pivotal role in the development of atherosclerosis in the intima of the blood vessels, i.e., monocytes and macrophages. Vitamin D is also involved in atherogenesis through inhibition of vascular smooth muscle cell proliferation. Furthermore, vitamin D deficiency is consistently associated with cardiovascular events, such as myocardial infarction, STEMI, NSTEMI, unstable angina, ischemic stroke, cardiovascular death, and increased mortality after acute stroke. Conversely, vitamin D supplementation does not seem to produce beneficial effects in cohorts with intermediate baseline vitamin D levels.

Does vitamin D administration play a role in outcome of patients with acute ischemic stroke? A randomized controlled trial

Background: Clinical studies have reported improved neurological outcomes in patients who were taking vitamin D supplements. This study investigates the effect of intramuscular (IM) vitamin D supplementation in patients with acute ischemic stroke (AIS) on neurological outcomes and inflammatory marker levels. Methods: This study included patients diagnosed with AIS (n = 60) from the Neurology Unit of Loghman Hakim Hospital, Tehran, Iran, during the year 2019. Patients with AIS were allocated randomly into two groups who received a single dose of 300000 IU IM vitamin D and a control group that did not receive vitamin D supplementation. Serum vitamin D concentration, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) levels, as primary outcomes, and the Modified Rankin Scale (MRS), the National Institute of Health Stroke Scale (NIHSS), and the Mini-Mental State Examination (MMSE), as secondary outcomes, were measured at the baseline and the end of the study (6 weeks). Results: Eventually, 59 patients with AIS completed the intervention study. A single dose of 300000 IU increased vitamin D level; moreover, vitamin D supplementation improved MRS and IL-6 levels significantly (P = 0.01, P = 0.02, respectively). There were reverse correlations between serum vitamin D and NIHSS and TNF-α after vitamin D administration. However, no statistically significant effect of vitamin D on the TNF-α or NIHSS and MMSE was seen compared to the control group. Conclusion: Vitamin D probably due to a single dose and short duration of administration, as well as a short follow-up period, had no favorable effects on TNF-α level and NIHSS score.

Post-ischemic stroke systemic inflammation: Immunomodulation by progesterone and vitamin D hormone

Post-stroke systemic inflammation, due to the injury itself and exacerbated by in-hospital infections, can increase morbidity and mortality in stroke patients. In this study, we examined the immunomodulatory effects of progesterone (P4) alone and in combination with vitamin D hormone (VDH) on acute phase post-stroke peripheral immune dysfunction and functional/behavioral deficits. Adult rats underwent transient middle cerebral artery occlusion/reperfusion (tMCAO) and delayed systemic inflammation was induced by injections of lipopolysaccharide (LPS) beginning 24 h post-stroke. Animals were tested for behavioral outcomes and immune function at day 4 post-stroke. We also measured infarction volume and markers of neuronal inflammation (GFAP, IL-6) and apoptosis (cleaved caspase-3) in brain post-stroke. We observed the worst stroke outcomes in the stroke + systemic inflammation group compared to the stroke-alone group. Flow cytometric analysis of different subsets of immune cells in blood, spleen and thymus revealed peripheral immune dysfunction which was restored by both P4 and VDH monotherapy. P4 monotherapy reduced infarction volume, behavioral/functional deficits, peripheral immune dysfunction, neuronal inflammation, and apoptosis induced by post-stroke systemic inflammation. Combination treatment with P4+VDH improved outcomes better than monotherapy. Our findings can be taken to suggest that the current standard of care for stroke and post-stroke infection can be substantially improved by P4 and VDH combination therapy.

Prevalence and Outcomes Associated with Vitamin D Deficiency among Indexed Hospitalizations with Cardiovascular Disease and Cerebrovascular Disorder-A Nationwide Study

Background: According to past studies, recovery and survival following severe vascular events such as acute myocardial infarction and stroke are negatively impacted by vitamin D deficiency. However, the national estimate on disability-related burden is unclear. We intend to evaluate the prevalence and outcomes of vitamin D deficiency (VDD) among patients with cardiovascular disease (CVD) and cerebrovascular disorder (CeVD). Methods: We performed a cross-sectional study on the Nationwide Inpatient Sample data (2016-2017) of adult (≥18 years) hospitalizations. We identified patients with a secondary diagnosis of VDD and a primary diagnosis of CVD and CeVD using the 9th revision of the International Classification of Diseases, clinical modification code (ICD-10-CM) codes. A univariate and mixed-effect multivariable survey logistic regression analysis was performed to evaluate the prevalence, disability, and discharge disposition of patients with CVD and CeVD in the presence of VDD. Results: Among 58,259,589 USA hospitalizations, 3.44%, 2.15%, 0.06%, 1.28%, 11.49%, 1.71%, 0.38%, 0.23%, and 0.08% had primary admission of IHD, acute MI, angina, AFib, CHF, AIS, TIA, ICeH, and SAH, respectively and 1.82% had VDD. The prevalence of hospitalizations due to CHF (14.66% vs. 11.43%), AIS (1.87% vs. 1.71%), and TIA (0.4% vs. 0.38%) was higher among VDD patients as compared with non-VDD patients (p < 0.0001). In a regression analysis, as compare with non-VDD patients, the VDD patients were associated with higher odds of discharge to non-home facilities with an admission diagnosis of CHF (aOR 1.08, 95% CI 1.07-1.09), IHD (aOR 1.24, 95% CI 1.21-1.28), acute MI (aOR 1.23, 95% CI 1.19-1.28), AFib (aOR 1.21, 95% CI 1.16-1.27), and TIA (aOR 1.19, 95% CI 1.11-1.28). VDD was associated with higher odds of severe or extreme disability among patients hospitalized with AIS (aOR 1.1, 95% CI 1.06-1.14), ICeH (aOR 1.22, 95% CI 1.08-1.38), TIA (aOR 1.36, 95% CI 1.25-1.47), IHD (aOR 1.37, 95% CI 1.33-1.41), acute MI (aOR 1.44, 95% CI 1.38-1.49), AFib (aOR 1.10, 95% CI 1.06-1.15), and CHF (aOR 1.03, 95% CI 1.02-1.05) as compared with non-VDD. Conclusions: CVD and CeVD in the presence of VDD increase the disability and discharge to non-home facilities among USA hospitalizations. Future studies should be planned to evaluate the effect of VDD replacement for improving outcomes.

Therapeutic potential of nutraceuticals to protect brain after stroke

Stroke leads to significant neuronal death and long-term neurological disability due to synergistic pathogenic mechanisms. Stroke induces a change in eating habits and in many cases, leads to undernutrition that aggravates the post-stroke pathology. Proper nutritional regimen remains a major strategy to control the modifiable risk factors for cardiovascular and cerebrovascular diseases including stroke. Studies indicate that nutraceuticals (isolated and concentrated form of high-potency natural bioactive substances present in dietary nutritional components) can act as prophylactic as well as adjuvant therapeutic agents to prevent stroke risk, to promote ischemic tolerance and to reduce post-stroke consequences. Nutraceuticals are also thought to regulate blood pressure, delay neurodegeneration and improve overall vascular health. Nutraceuticals potentially mediate these effects by their powerful antioxidant and anti-inflammatory properties. This review discusses the studies that have highlighted the translational potential of nutraceuticals as stroke therapies.

Vitamin D and Stroke: Effects on Incidence, Severity, and Outcome and the Potential Benefits of Supplementation

Vitamin D serum level has been positively associated with improved cardiovascular health, especially with reduction of stroke risk. This systemic review summarizes and synthesizes findings from studies relevant to the relationship between vitamin D and stroke risk, severity, and outcome; potential mechanisms explaining such a relationship; and outcomes from vitamin D supplementation. The literature shows that vitamin D deficiency is a significant risk factor for ischemic stroke, with sun exposure, sex, age, race, diabetes, and genetics playing a role as well. Stroke severity and short- and long-term outcomes also worsen with vitamin D deficiency. The neuroprotective mechanisms by which vitamin D operates to mitigate stroke onset and outcomes have yet to be fully studied, but researchers have proposed several pathways, including promotion of certain neuroprotective growth factors, reduction of arterial pressure through vasodilation, and inhibition of reactive oxygen species. There is some evidence that vitamin D supplementation could lower stroke risk and improve recovery, though outcomes can also be negligible or negative. Although results are mixed and the limitations of vitamin D supplementation merit some caution, vitamin D overall plays a significant role in stroke health. Future research should further develop understanding of the neuroprotective mechanisms of vitamin D and study how supplementation could be administered effectively in stroke treatment.

Vitamin D Deficiency and the Risk of Cerebrovascular Disease

Vitamin D deficiency has been clearly linked to major chronic diseases associated with oxidative stress, inflammation, and aging, including cardiovascular and neurodegenerative diseases, diabetes, and cancer. In particular, the cardiovascular system appears to be highly sensitive to vitamin D deficiency, as this may result in endothelial dysfunction and vascular defects via multiple mechanisms. Accordingly, recent research developments have led to the proposal that pharmacological interventions targeting either vitamin D deficiency or its key downstream effects, including defective autophagy and abnormal pro-oxidant and pro-inflammatory responses, may be able to limit the onset and severity of major cerebrovascular diseases, such as stroke and cerebrovascular malformations. Here we review the available evidence supporting the role of vitamin D in preventing or limiting the development of these cerebrovascular diseases, which are leading causes of disability and death all over the world.

Serum vitamin D levels in acute stroke patients

Background

Vitamin D deficiency has been proposed as a risk factors of cerebrovascular stroke.

Objectives

The aim of this study was firstly, to assess the serum level of vitamin D in cerebral stroke patients and secondly, to examine if its deficiency was associated with stroke severity and outcome.

Methods

We utilized a case-control study design and recruited 138 acute stroke patients and 138 age- and sex-matched controls from subjects attending outpatient clinic for other reasons. All participants were subjected to full general and neurological examination. Brain imaging CT and/or MRI was performed. Blood samples were collected for measurement of serum level of vitamin D (ng/ml) by ELISA, alkaline phosphatase, serum calcium, and phosphorous. The stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) and stroke outcome was assessed by modified Rankin Scale (mRS).

Results

Stroke patients had significant lower levels of vitamin D compared with the control group. Vitamin D deficiency remained significantly associated with the NIHSS stroke severity score and the mRS 3-month stroke outcome after controlling for other significant factors such as age, dyslipidemia, and infarction size using multivariable logistic regression analysis.

Conclusion

Our results demonstrated that stroke patients suffer from vitamin D deficiency, which was associated with both stroke severity and poor outcome. Vitamin D supplementation could exert a therapeutic role in the management of cerebral stroke.

Prognostic utility of serum 25-hydroxyvitamin D in patients with stroke: a meta-analysis

BACKGROUND

Conflicting findings have been reported on the prognostic significance of serum 25-hydroxyvitamin D level in patients with stroke. The objective of this meta-analysis was to evaluate the prognostic utility of serum 25-hydroxyvitamin D in stroke patients.

METHODS

PubMed and Embase databases were systematically searched for potentially eligible studies until October 16, 2019. Observational studies investigating the association between serum 25-hydroxyvitamin D level and prognosis of patients with stroke were eligible. Multivariable adjusted risk ratios (RR) with 95% confidence intervals (CI) of poor functional outcome, all-cause mortality, and recurrence of stroke were pooled with the lowest versus the highest category of 25-hydroxyvitamin D level.

RESULTS

Eleven articles (ten studies) involving 6845 stroke patients satisfied our predefined inclusion criteria. Lower serum 25-hydroxyvitamin D level was associated with an increased risk of poor functional outcome (RR 1.86; 95% CI 1.16-2.98), all-cause mortality (RR 3.56; 95% CI 1.54-8.25), and recurrence of stroke (RR 5.49; 95% CI 2.69-11.23). Sensitivity analysis further confirmed the above findings.

CONCLUSIONS

Lower serum 25-hydroxyvitamin D level is significantly associated with poorer prognosis in stroke patients. Future prospective studies are warranted to verify the prognostic role and to examine the association in different subtypes of stroke.