Folic Acid Therapy Reduces the First Stroke Risk Associated With Hypercholesterolemia Among Hypertensive Patients

Folic acid and plasma lipids: Interactions and effect of folate supplementation

Dyslipidaemia and hyperhomocysteinemia are known risk factors for cardiovascular disease. While it is evident that optimization of plasma lipid is associated with low risk of cardiovascular disease in the general population, it is not yet fully clear whether reduction of homocysteinemia is associated with an improvement in risk in all subjects. The aim of our narrative review is to highlight eventual effects of folate supplementation on LDL-C levels, LDL-C oxidation and atherosclerosis-related complications. A comprehensive literature search was done in electronic database, including PubMed, Web of Science, Cochrane, and Scopus from inception up to January 2024. Based on the available evidence, epidemiological data, pathophysiological observations and meta-analyses of randomized clinical trials suggest that folic acid supplementation may modestly but significantly improve plasma lipid levels, lipid atherogenicity, and atherosclerosis-related early vascular damage, and that folic acid supplementation may significantly reduce the risk of cerebrovascular disease. Considering the low-cost and high safety profile of folic acid, its long-term supplementation could be considered for dyslypidaemic patients in secondary prevention for cardiovascular disease.

Association between plasma total homocysteine (tHcy) and strokes: A meta-analysis

Objective

Inconsistent findings have been reported regarding the association between elevated plasma total homocysteine (tHcy) and the risk of different types of strokes. We conducted this meta-analysis to identify the association between tHcy and different kinds of strokes or recurrences of strokes, and provide evidence for preventing.

Methods

Relevant studies published before May 1, 2022 in databases such as PubMed, EMBASE, the Cochrane Library, CNKI, and Wanfang were retrieved. Two researchers independently searched and extracted the data, and used Stata 16.0 statistical software for analysis. Results were presented as the odds risk (OR) and the corresponding 95% confidence intervals (CI).

Results

In total, 24 articles were included, involving 51,426 subjects, of which 4,983 had stroke events during follow-up. Relative to lower tHcy, higher tHcy were associated with increased stroke (OR = 1.95, 95% CI: 1.59–2.37), ischemic stroke (OR = 1.71, 95% CI: 1.39–2.11), hemorrhagic stroke (OR = 1.99, 95% CI: 1.03–3.84), and recurrent stroke (OR = 1.25, 95% CI: 1.12–1.39), respectively.

Conclusions

This study shows that elevated tHcy increases the risk of stroke, including ischemic stroke and hemorrhagic stroke, and is closely related to the recurrence of stroke. It is recommended to pay attention to the detection of tHcy in the management of stroke patients in the future, and take effective measures to prevent and delay the progression of stroke.

Problem in the Recent American Heart Association Guideline on Secondary Stroke Prevention: B Vitamins to Lower Homocysteine Do Prevent Stroke

In this article, we discuss a problem in the most recent American Heart Association guideline on secondary stroke prevention that apparently arose from the rules of evidence imposed on the guideline panel. We are told by the cochair of the panel that American Heart Association rules about guidelines for secondary prevention prohibited consideration of primary prevention studies and secondary analyses of secondary prevention studies. However, evidence-based medicine should consider all the best external evidence available and also clinical judgement. The most important problem in the guideline was the recommendation that B vitamins to lower homocysteine do not prevent recurrent stroke. When considering all the best external evidence, it is clear that B vitamins do prevent stroke, but in the early secondary stroke prevention studies, the benefit of B vitamins in participants with good renal function was apparently offset by harm from cyanocobalamin among participants with renal failure (level B-R evidence). We review the evidence that B vitamins should be used to prevent stroke, both in primary and secondary stroke prevention (class 2a recommendation). We also review issues in folate metabolism that require further study, with regard to the form of folate to be used for stroke prevention. We recommend that the guideline be revised to say that B vitamins to lower homocysteine prevent stroke and that methylcobalamin or hydroxycobalamin should be used instead of cyanocobalamin.

Vitamin B12 and chronic kidney disease

Chronic Kidney Disease (CKD) is an emerging public health issue with a fast-growing global prevalence. Impairment in vitamin B12 metabolism is considered a nontraditional risk factor of poor outcomes associated with CKD, and there is greater interest from the scientific community than ever before to explore the role and influence of vitamin B12 in CKD. Homocysteine metabolism forms an important component of the vitamin B12 metabolic pathway. Hyperhomocysteinemia is frequently observed in CKD and End-Stage Kidney Disease (ESKD), but its representation as a prognostic marker for CKD outcomes is still not fully clear. This chapter reviews the vitamin B12 and homocysteine metabolic pathways and their dysfunction in CKD states. Biochemical factors and the MTHFR genetic polymorphisms which disrupt vitamin B12 and homocysteine metabolism are explored. The mechanisms of homocysteine-mediated and vitamin B12-mediated tissue damage in CKD are discussed. This chapter reviews current perspective on definition and measurement of plasma vitamin B12 levels in the CKD population. Updated evidence investigating the prognostic role of vitamin B12 for CKD outcomes is presented. Findings from major clinical trials conducted relating to outcomes from multivitamin (including folic acid and vitamin B12) supplementation in nondialysis and dialysis-dependent CKD are highlighted. The prognostic value of vitamin B12 and effects of vitamin B12 supplementation in the context of kidney transplantation and acute kidney injury is also reviewed. Future research considerations are summarized based on evidence gaps in our knowledge base of this topic. Greater abundance of high-level evidence to guide an approach toward vitamin B12 measurement, monitoring and supplementation in CKD may contribute to improved clinical outcomes.

Association Between Hyperhomocysteinemia Combined with Metabolic Syndrome and Higher Prevalence of Stroke in Chinese Adults Who Have Elevated Blood Pressure

Background

Hyperhomocysteinemia (HHcy) and metabolic syndrome (MS) are established cardiovascular risk factors of stroke and are frequently associated with hypertension. However, studies on the association between HHcy combined with MS and stroke risk in hypertensive patients were absent.

Material/Methods

In 14 059 selected participants with elevated blood pressure, we assessed the prevalence of the MS and stroke. We defined HHcy as plasma total homocysteine >15 μmol/L. MS was defined according to the Chinese Diabetes Society (CDS) criterion. Multivariable analysis was used to examine the association of HHcy or (and) MS with stroke risk in different models.

Results

The prevalence rates of HHcy and MS were 49.96% and 42.21%, respectively. Patients with stroke had higher plasma total homocysteine levels and a higher prevalence of MS (P<0.001). Multivariable analyses indicated that HHcy and MS are independently associated with higher prevalence of stroke (adjusted-odds ratio (OR): 1.36, 95% CI 1.17 to 1.58, P<0.001; adjusted-OR: 1.68, 95% CI 1.44 to 1.96, P<0.001, respectively). Those with combined HHcy and MS had higher odds of stroke than those with isolated HHcy or MS (adjusted-OR: 1.78, 95% CI 1.47 to 2.15, P<0.001; adjusted-OR: 1.39, 95% CI 1.13 to 1.70, P=0.002, respectively).

Conclusions

HHcy combined with MS was associated with higher prevalence of stroke in Chinese adults with elevated blood pressure.

Managing folate deficiency implies filling the gap between laboratory and clinical assessment

The characterization of folate status in subjects at risk of deficiency and with altered vitamin homeostasis is crucial to endorse preventive intervention health policies, especially in developed countries. Several physiological changes (i.e. pregnancy), clinical situations and diseases have been associated to increased requirement, impaired intake and absorption of folate. However clinical practice guidelines (CPG) endorse folic acid supplementation generally discarding the use of its determination in serum to assess the risk of deficiency and/or its concentration at baseline. Poor confidence on the diagnostic accuracy of serum folate assays still persists in the current CPGs although recent standardization efforts have greatly improved inter-method variability and precision. In this review we critically appraise the methodological issues concerning laboratory folate determination and the evidence on the potential adverse effects of folic acid exposure. The final aim is to build a sound background to promote serum folate-based cost-effective health care policies by optimizing folic acid supplementation in subjects at risk of deficiency and with altered folate homeostasis. Our first result was to adjust in relation to current serum folate assays the thresholds reported by CPGs as index of folate status, defined on the association with metabolic and hematologic indicators. We identify a statistically significant difference between the estimated thresholds and accordingly show that the assessment of folate status actually changes in relation to the assay employed. The use of the method-dependent thresholds here reported may pragmatically endorse the stewardship of folic acid supplementation in clinical practice and increase the cost-effectiveness of health care policies.

Predicting Risk of Stroke From Lab Tests Using Machine Learning Algorithms: Development and Evaluation of Prediction Models

Background

Stroke, a cerebrovascular disease, is one of the major causes of death. It causes significant health and financial burdens for both patients and health care systems. One of the important risk factors for stroke is health-related behavior, which is becoming an increasingly important focus of prevention. Many machine learning models have been built to predict the risk of stroke or to automatically diagnose stroke, using predictors such as lifestyle factors or radiological imaging. However, there have been no models built using data from lab tests.

Objective

The aim of this study was to apply computational methods using machine learning techniques to predict stroke from lab test data.

Methods

We used the National Health and Nutrition Examination Survey data sets with three different data selection methods (ie, without data resampling, with data imputation, and with data resampling) to develop predictive models. We used four machine learning classifiers and six performance measures to evaluate the performance of the models.

Results

We found that accurate and sensitive machine learning models can be created to predict stroke from lab test data. Our results show that the data resampling approach performed the best compared to the other two data selection techniques. Prediction with the random forest algorithm, which was the best algorithm tested, achieved an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve of 0.96, 0.97, 0.96, 0.75, 0.99, and 0.97, respectively, when all of the attributes were used.

Conclusions

The predictive model, built using data from lab tests, was easy to use and had high accuracy. In future studies, we aim to use data that reflect different types of stroke and to explore the data to build a prediction model for each type.

The significance of homocysteine in patients with hypertension

Cardiovascular disease is the most common cause of death in developed countries. Important factors leading to ischemic heart disease and strokes are hypertension and high levels of homocysteine in blood serum. The coexistence of these two factors significantly increases the risk of these diseases and premature deaths. Many studies indicate that patients with hypertension are significantly more likely to demonstrate increased blood serum homocysteine levels than those with normal blood pressure. This may be caused by a higher incidence of overweight, high intake of salt and increased uric acid levels. It has been shown that both these factors increase the prevalence of hypertension and lead to higher homocysteine levels. However, the results of some studies indicate that arterial hypertension and homocysteinemia are causally related. It was shown, among other things, that high homocysteine levels damage the endothelium and reduce nitric oxide synthesis, which may directly lead to hypertension. Serum homocysteine levels are slightly higher in patients with white coat hypertension than they are in healthy individuals and may therefore also increase the risk of cardiovascular diseases. Several authors have also shown that the levels of homocysteine in blood serum are higher in so-called non-dippers, i.e., patients with no night-time pressure drop. The lack of a 10%–20% decrease in blood pressure at night is associated with increased cardiovascular complications. Strokes occur especially frequently in older people with arterial hypertension and hyperhomocysteinemia. The administration of B vitamins and folic acid significantly reduces serum homocysteine levels. The administration of this acid also slightly, but statistically significantly, increases the effectiveness of hypotensive drugs. Large meta-analyses meta-analysis indicate that the increased supply of folic acid in patients with hypertension significantly reduces the risk of stroke. Such management is particularly effective in patients with hypertension and hyperhomocysteinemia.

Homocysteine - from disease biomarker to disease prevention

We have reviewed the literature and have identified more than 100 diseases or conditions that are associated with raised concentrations of plasma total homocysteine. The commonest associations are with cardiovascular diseases and diseases of the central nervous system, but a large number of developmental and age-related conditions are also associated. Few other disease biomarkers have so many associations. The clinical importance of these associations becomes especially relevant if lowering plasma total homocysteine by B vitamin treatment can prevent disease and so improve health. Five diseases can at least in part be prevented by lowering total homocysteine: neural tube defects, impaired childhood cognition, macular degeneration, primary stroke, and cognitive impairment in the elderly. We conclude from our review that total homocysteine values in adults of 10 μmol/L or below are probably safe, but that values of 11 μmol/L or above may justify intervention. Homocysteine is more than a disease biomarker: it is a guide for the prevention of disease.

Folic acid supplementation and blood pressure: a GRADE-assessed systematic review and dose-response meta-analysis of 41,633 participants

Hypertension is a predisposing factor for cardiovascular disease (CVD). The extant literature regarding the effects of folic acid supplementation on blood pressure (BP) is inconsistent. Therefore, this systematic review and meta-analysis of randomized controlled trials was conducted to summarize the effects of folic acid supplementation on BP. A systematic search was carried out in PubMed, Scopus, ISI Web of Science, and Cochrane library, from database inception to August 2021. Data were pooled using the random-effects method and were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). The pooled results of 22 studies, including 41,633 participants, showed that folic acid supplementation significantly decreased systolic BP (SBP) (WMD: -1.10 mmHg; 95% CI: -1.93 to -0.28; p = 0.008). Subgroup analysis showed that the results remained significant when baseline SBP was ≥120 mmHg, intervention duration was ≤6 weeks, intervention dose was ≥5 mg/d, in patients with CVD, males and females, and overweight participants, respectively. Furthermore, the changes observed in diastolic BP (DBP) (WMD: -0.24 mmHg; 95% CI: -0.37 to -0.10; p < 0.001) were also statistically significant. However, subgroup analysis showed that the results remained significant in subject with elevated DBP, long term duration of intervention (>6 weeks), low dose of folic acid (<5 mg/day), CVD patients, both sexes and male, and participants with normal BMI. Dose-response analysis showed that folic acid supplementation changed SBP and DBP significantly based on dose and duration. However, meta-regression analysis did not reveal any significant association between dose and duration of intervention with changes in SBP. The present study demonstrates the beneficial effects of folic acid supplementation on BP by decreasing both SBP and DBP.

Supplemental Vitamins and Minerals for Cardiovascular Disease Prevention and Treatment: JACC Focus Seminar

This is an update of the previous 2018 systematic review and meta-analysis of vitamin and mineral supplementation on cardiovascular disease outcomes and all-cause mortality. New randomized controlled trials and meta-analyses were identified by searching the Cochrane library, Medline, and Embase, and data were analyzed using random effects models and classified by the Grading of Recommendations Assessment Development and Evaluation approach. This updated review shows similar findings to the previous report for preventive benefits from both folic acid and B vitamins for stroke and has been graded with moderate quality. No effect was seen for the commonly used multivitamins, vitamin D, calcium, and vitamin C, and an increased risk was seen with niacin (with statin) for all-cause mortality. Conclusive evidence for the benefit of supplements across different dietary backgrounds, when the nutrient is sufficient, has not been demonstrated.

Stroke Prevention: Little-Known and Neglected Aspects

Combining available therapies has the potential to reduce the risk of stroke by 80% or more. A comprehensive review of all aspects of stroke prevention would be very lengthy; in this narrative review, we focus on some aspects of stroke prevention that are little-known and/or neglected. These include the following: (1) implementation of a Mediterranean diet; (2) B vitamins to lower homocysteine; (3) coordinated approaches to smoking cessation; (4) intensive lipid-lowering therapy; (5) lipid lowering in the elderly; (6) physiologically individualized therapy for hypertension based on renin/aldosterone phenotyping; (7) avoiding excessive blood pressure reduction in patients with stiff arteries; (8) treatment of insulin resistance with pioglitazone in stroke patients with prediabetes and diabetes; (9) impaired activation of clopidogrel in patients with variants of CYP2C19; (10) aspirin pseudoresistance due to enteric coating; (11) rationale for anticoagulation in patients with embolic stroke of unknown source; (12) pharmacologic properties of direct-acting oral anticoagulants that should be considered when choosing among them; (13) the identification of which patients with asymptomatic carotid stenosis are at a high enough risk to benefit from carotid endarterectomy or stenting; and (14) the importance of age in choosing between endarterectomy and stenting. Stroke prevention could be improved by better recognition of these issues and by implementation of the principles derived from them.

Appraising the Causal Association of Plasma Homocysteine Levels With Atrial Fibrillation Risk: A Two-Sample Mendelian Randomization Study

Background

Although several observational studies have suggested an association of elevated plasma homocysteine (Hcy) levels with increased risk of atrial fibrillation (AF), it remains unclear whether this association reflects causality. In this study, we aimed to investigate the causal association of plasma Hcy levels with AF risk.

Methods

A two-sample Mendelian randomization (MR) study was designed to investigate the causal association of Hcy with AF. Summary data on association of single nucleotide polymorphisms (SNPs) with Hcy were extracted from the hitherto largest genome-wide association study (GWAS) with up to 44,147 individuals, and statistics data on association of SNPs with AF were obtained from another recently published GWAS with up to 1,030,836 individuals. SNPs were selected at a genome-wide significance threshold (p < 5 × 10^–8). Fixed-effect inverse variance weighting (IVW) method was used to calculate the causal estimate. Other statistical methods and leave-one-out analysis were applied in the follow-up sensitivity analyses. MR-Egger intercept test was conducted to detect the potential directional pleiotropy.

Results

In total, nine SNPs were identified as valid instrumental variables in our two-sample MR analysis. Fixed-effect IVW analysis indicated no evidence of causal association of genetically predicted Hcy with AF. The odds ratio (OR) and 95% confidence interval (CI) of AF per standard deviation (SD) increase in Hcy were 1.077 (0.993, 1.168), p = 0.075. Similar results were observed in the sensitivity analyses. MR-Egger intercept test suggested no evidence of potential horizonal pleiotropy.

Conclusions

This two-sample MR analysis found no evidence to support causal association of Hcy with AF.

Beneficial effects of folic acid supplementation on lipid markers in adults: A GRADE-assessed systematic review and dose-response meta-analysis of data from 21,787 participants in 34 randomized controlled trials

Folic acid supplementation has received considerable attention in the literature, yet there is a large discrepancy in its effects on lipid markers in adults. Therefore, this systematic review and meta-analysis of 38 randomized controlled trials (RCTs) evaluated the effects of folic acid supplementation on triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol concentrations in a cohort of 21,787 participants. A systematic search current as of March 2021 was performed in PubMed/Medline, Scopus, Web of Science, and Embase using relevant keywords to identify eligible studies. A fix or random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence intervals (CIs). Thirty-four RCTs were included in this meta-analysis. The pooled analysis revealed that serum TG (WMD: -9.78 mg/dL; 95% CI: -15.5 to -4.00; p = 0.001, I²=0.0%, p = 0.965) and TC (WMD: -3.96 mg/dL; 95% CI: -6.71 to -1.21; p = 0.005, I²=46.9%, p = 0.001) concentrations were significantly reduced following folic acid supplementation compared to placebo. However, folic acid supplementation did not affect serum concentrations of LDL (WMD: -0.97 mg/dL; 95% CI: -6.82 to 4.89; p = 0.746, I²=60.6%, p < 0.001) or HDL cholesterol (WMD: 0.44 mg/dL; 95% CI: -0.53 to 1.41; p = 0.378, I²= 0.0%, p = 0.831). A significant dose-response relationship was observed between the dose of folic acid supplementation and serum concentrations of HDL cholesterols (r = 2.22, p = 0.047). Folic acid supplementation reduced serum concentrations of TG and TC without affecting LDL or HDL cholesterols. Future large RCTs on various populations are needed to show further beneficial effects of folic acid supplementation on lipid profile.

Shunaoxin pills improve the antihypertensive effect of nifedipine and alleviate its renal lipotoxicity in spontaneous hypertension rats

Shunaoxin pills (SNX) have been used to treat cerebrovascular diseases in China since 2005. Hypertension is a major risk factor for cerebrovascular disease. This study aimed to explore the synergistic antihypertensive effect of SNX and nifedipine and whether SNX could alleviate nifedipine-induced renal lipotoxicity. During administration, systolic blood pressure was measured weekly. After 5 weeks administration, we examined pathological changes of kidney, renal function, the lipid metabolism index, and adipogenesis genes expression in the kidney tissues, and explored its underlying mechanism. Finally, network pharmacology was used for supplement and verification. As a result, SNX improved the antihypertensive effect of nifedipine and apparently improved nifedipine-induced renal pathological changes, dyslipidemia and the levels of adipogenesis gene expression in kidney tissues. SNX reduced the levels of interleukin-6 and interleukin-1β in renal tissues, down-regulated the production of malondialdehyde, and increased superoxide dismutase activity and the protein expression of heme oxygenase-1 in kidney tissues. Network pharmacology also showed that SNX could improve nifedipine-induced renal lipotoxicity. The combination of SNX and nifedipine had certain benefits in the treatment of hypertension.

Serum folate modified the association between low-density lipoprotein cholesterol and carotid intima-media thickness in Chinese hypertensive adults

BACKGROUND AND AIMS

While folate is known for its importance in cardiovascular health, it is unknown whether folate status can modify the association between low-density lipoprotein cholesterol (LDL-C) and carotid intima-media thickness (CIMT). We aimed to investigate this question in a Chinese hypertensive population, who are at high-risk of low folate and atherosclerosis.

METHODS AND RESULTS

This report included 14,970 hypertensive adults (mean age 64.5 years; 40.3% male) from the China Stroke Primary Prevention Trial (CSPPT) and analyzed the fasting serum LDL-C and folate, and CIMT data obtained at the last follow-up visit. LDL-C was calculated using the Friedewald equation. Serum folate levels were measured by chemiluminescent immunoassay. CIMT was measured by ultrasound. Non-parametric smoothing plots, multivariate linear regression analysis, subgroup analyses and interaction testing were performed to examine the LDL-C-CIMI relationship and effect modification by folate. Consistent with graphic plots, multivariate linear regression showed that LDL-C levels were independently and positively associated with CIMT (β = 7.69, 95%CI: 5.76-9.62). More importantly, the relationship between LDL-C and CIMT was significantly attenuated with increasing serum folate levels (1st tertile: β = 10.06, 95%CI: 6.67-13.46; 2nd tertile: β = 6.81, 95%CI: 3.55-10.07; 3rd tertile: β = 5.96, 95%CI: 2.55-9.36; P-interaction = 0.045). Subgroup analyses showed the association between LDL-C and CIMT across serum folate tertiles was robust among various strata (all P-interaction >0.05).

CONCLUSIONS

Among Chinese hypertensive adults, the serum folate levels could modify the association between LDL-C and CIMT. Our findings, if further confirmed, have important clinical implications.

The importance of homocysteine in the development of cardiovascular complications in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) not only leads to disability due to joint changes, but also significantly shortens the life expectancy of patients, mainly due to more frequent occurrence of heart attacks and strokes. Accelerated atherosclerosis in these patients is caused, among other factors, by high homocysteine (HCY) concentration in blood. Numerous studies have shown that treatment with vitamin B significantly reduces the concentration of HCY in blood, but does not reduce the risk of heart diseases. Recent studies have shown, however, that folic acid (FA) administration reduces the risk of stroke by 10–20%. Due to the fact that in patients with RA strokes are more frequent than in the general population and hyperhomocysteinemia (HHCY) is often found, determination of HCY concentration in blood is advisable, and in persons with HHCY it is recommended to use FA in primary and secondary stroke prevention.

The Antioxidant Role of One-Carbon Metabolism on Stroke

One-carbon (1C) metabolism is a metabolic network that is centered on folate, a B vitamin; it integrates nutritional signals with biosynthesis, redox homeostasis, and epigenetics. This metabolic pathway also reduces levels of homocysteine, a non-protein amino acid. High levels of homocysteine are linked to increased risk of hypoxic events, such as stroke. Several preclinical studies have suggested that 1C metabolism can impact stroke outcome, but the clinical data are unclear. The objective of this paper was to review preclinical and clinical research to determine whether 1C metabolism has an antioxidant role on stroke. To accomplish the objective, we searched for publications using the following medical subject headings (MeSH) keywords: antioxidants, hypoxia, stroke, homocysteine, one-carbon metabolism, folate, methionine, and dietary supplementation of one-carbon metabolism. Both pre-clinical and clinical studies were retrieved and reviewed. Our review of the literature suggests that deficiencies in 1C play an important role in the onset and outcome of stroke. Dietary supplementation of 1C provides beneficial effects on stroke outcome. For stroke-affected patients or individuals at high risk for stroke, the data suggest that nutritional modifications in addition to other therapies could be incorporated into a treatment plan.

Management of asymptomatic carotid stenosis

Patients with asymptomatic carotid stenosis (ACS) are at very high risk of coronary events, so they should all receive intensive medical therapy. What is often accepted as “best medical therapy” is usually suboptimal. Truly intensive medical therapy includes lifestyle modification, particularly smoking cessation and a Mediterranean diet. All patients with ACS should receive intensive lipid-lowering therapy, should have their blood pressure well controlled, and should receive B vitamins for lowering of plasma total homocysteine (tHcy) if levels are high; a commonly missed cause of elevated tHcy is metabolic B12 deficiency, which should be diagnosed and treated. Most patients with ACS would be better treated with intensive medical therapy than with either carotid endarterectomy (CEA) or stenting (CAS). A process called “treating arteries instead of treating risk factors” markedly reduced the risk of ACS in an observational study; a randomized trial vs. usual care should be carried out. The few patients with ACS who could benefit (~15%, or perhaps more if recent evidence regarding the risk of intraplaque hemorrhage is borne out) can be identified by a number of features. These include microemboli on transcranial Doppler, intraplaque hemorrhage, reduced cerebrovascular reserve, and echolucency of plaques, particularly “juxtaluminal black plaque”. No patient should be subjected to CAS or CEA without evidence of high-risk features, because in most cases the 1-year risk of stroke or death with intervention is higher with either CEA (~2%) or CAS (~4%) than with intensive medical therapy (~0.5%). Most patients, particularly the elderly, would be better treated with CEA than CAS. Most strokes can be prevented in patients with ACS, but truly intensive medical therapy is required.

Nomogram Including Neutrophil-to-Lymphocyte Ratio for the Prediction of Stroke-Associated Infections

Stroke has been a leading cause of mortality in China. Stroke-associated infections (SAI) are common complications, occurring in 5–65% of stroke patients. Faced with SAI, clinicians often are placed in a considerable dilemma. On the one hand, preventive overuse of antibiotics will lead to the emergence of drug-resistant bacteria. On the other hand, treatment delay of the infection will likely result in a poor outcome. Therefore, it is necessary to determine the early predictors of post-stroke infection to screen patients with high infection risk for early clinical intervention, thereby promoting and improving survival rates. We assessed 257 patients with acute ischemic stroke from a consecutive retrospective cohort. Data of these patients were obtained from three hospitals (TongJi Hospital and its two branches) between August 2018 and June 2019. Of these patients, 59 (23.0%) developed SAI. SAI was defined according to the modified Centers for Disease Control and Prevention criteria. There were 38 patients (64.4%) who developed pneumonia, 11 with urinary tract infections (18.6%), and 10 with other infections (16.9%). We found that a higher neutrophil-to-lymphocyte ratio (adjusted odds ratio [aOR] = 1.16; 95% confidence interval [CI], 1.01–1.33; P = 0.034), National Institutes of Health Stroke Scale score (aOR = 1.18; CI, 1.09–1.27; p < 0.001), and dysphagia (aOR = 2.95; CI, 1.40–6.22; P = 0.004) were risk factors for SAI. Of note, hypertriglyceridemia (aOR = 0.35; CI, 0.13–0.90; P = 0.029) was a protective factor, lowering the risk of SAI. To this end, a reliable nomogram was constructed for the prediction of SAI in our study (mean C-index value ± standard deviation = 0.821 ± 0.03). It has the potential to be widely used and may help identify patients at high risk for SAI and make timely clinical decisions. Given our study was based on relatively small dataset, the results should be interpreted with care and external validation in independent datasets is very necessary.

Stroke Prevention in Older Adults: Recent Advances

The risks of stroke and dementia increase steeply with age, and both are preventable. At present, the best way to preserve cognitive function is to prevent stroke. Therapeutic nihilism based on age is common and unwarranted. We address recent advances in stroke prevention that could contribute greatly to prevention of stroke and dementia at a time when the aging of the population threatens to markedly increase the incidence of both. Issues discussed: (1) old patients benefit even more from lipid-lowering therapy than do younger patients; (2) patients with stiff arteries are at risk from a target systolic blood pressure <120 mm Hg; (3) the interaction of the intestinal microbiome, age, and renal function has important dietary implications for older adults; (4) anticoagulation with direct-acting oral anticoagulants should be prescribed more to old patients with atrial fibrillation; (5) B vitamins to lower homocysteine prevent stroke; and (6) most old patients in whom intervention is warranted for carotid stenosis would benefit more from endarterectomy than from stenting. An 80-year-old person has much to lose from a stroke and should not have effective therapy withheld on account of age. Lipid-lowering therapy, a more plant-based diet, appropriate anticoagulation or antiplatelet therapy, appropriate blood pressure control, B vitamins to lower homocysteine, and judicious intervention for carotid stenosis could do much to reduce the growing burden of stroke and dementia.

Stroke Prevention

In 44 years of practicing stroke prevention, I have learned many lessons; in this article, I hope to impart some of them. Three areas of my research are discussed. Controlling resistant hypertension is markedly improved by physiologically individualized therapy based on renin/aldosterone phenotyping; this is particularly important in black patients. Measurement of carotid plaque burden strongly predicts cardiovascular risk and is useful for genetic research and for a process called treating arteries instead of risk factors. Doing so in high-risk patients with asymptomatic carotid stenosis was associated with a >80% reduction in the 2-year risk of stroke and myocardial infarction. It also permitted the identification of extremes of atherosclerosis that are useful for studying both the genetics and the biology of atherosclerosis. Patients with very high plaque burden despite low levels of risk factors have an unexplained phenotype; those with little or no plaque despite high levels of risk factors are protected. Patients with unexplained atherosclerosis have higher plasma levels of toxic metabolites produced by the intestinal microbiome largely from egg yolk, red meat, and protein, and those metabolites are renally excreted. This has important dietary implications for stroke prevention. Lowering of plasma total homocysteine with B vitamins significantly reduces the risk of stroke. That was not apparent in early studies because harm from cyanocobalamin among participants with renal failure obscured the benefit among those with good renal function. We should be using B vitamins to prevent stroke but should use methylcobalamin or oxocobalamin instead of cyanocobalamin.

Baseline Serum Bilirubin and Risk of First Stroke in Hypertensive Patients

Background

Data on the association between serum bilirubin and the risk of stroke are limited and inconclusive. We aimed to evaluate the association between serum bilirubin and the risk of first stroke and to examine any possible effect modifiers in hypertensive patients.

Methods and Results

Our study was a post hoc analysis of the CSPPT (China Stroke Primary Prevention Trial). A total of 19 906 hypertensive patients were included in the final analysis. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% CIs for the risk of first stroke associated with serum bilirubin levels. The median follow‐up period was 4.5 years. When serum total bilirubin was assessed as tertiles, the adjusted HR of first ischemic stroke for participants in tertile 3 (12.9–34.1 μmol/L) was 0.75 (95% CI, 0.59–0.96), compared with participants in tertile 1 (<9.3 μmol/L). When direct bilirubin was assessed as tertiles, a significantly lower risk of first ischemic stroke was also found in participants in tertile 3 (2.5–24.8 μmol/L) (adjusted HR, 0.77; 95% CI, 0.60–0.98), compared with those in tertile 1 (<1.6 μmol/L). However, there was no significant association between serum total bilirubin (tertile 3 versus 1: adjusted HR, 1.45; 95% CI, 0.89–2.35) or direct bilirubin (tertile 3 versus 1: adjusted HR, 1.27; 95% CI, 0.76–2.11) and first hemorrhagic stroke.

Conclusions

In this sample of Chinese hypertensive patients, there was a significant inverse association between serum total bilirubin or direct bilirubin and the risk of first ischemic stroke.

Endothelial Dysfunction May Link Interatrial Septal Abnormalities and MTHFR-Inherited Defects to Cryptogenic Stroke Predisposition

We explored the significance of the L-Arginine/asymmetric dimethylarginine (L-Arg/ADMA) ratio as a biomarker of endothelial dysfunction in stroke patients. To this aim, we evaluated the correlation, in terms of severity, between the degree of endothelial dysfunction (by L-Arg/ADMA ratio), the methylene tetrahydrofolate reductase (MTHFR) genotype, and the interatrial septum (IAS) phenotype in subject with a history of stroke. Methods and Results: L-Arg, ADMA, and MTHFR genotypes were evaluated; the IAS phenotype was assessed by transesophageal echocardiography. Patients were grouped according to the severity of IAS defects and the residual enzymatic activity of MTHFR-mutated variants, and values of L-Arg/ADMA ratio were measured in each subgroup. Of 57 patients, 10 had a septum integrum (SI), 38 a patent foramen ovale (PFO), and 9 an ostium secundum (OS). The L-Arg/ADMA ratio differed across septum phenotypes (p ≤ 0.01), and was higher in SI than in PFO or OS patients (p ≤ 0.05, p ≤ 0.01, respectively). In the PFO subgroup a negative correlation was found between the L-Arg/ADMA ratio and PFO tunnel length/height ratio (p ≤ 0.05; r = − 0.37; R2 = 0.14). Interestingly, the L-Arg/ADMA ratio varied across MTHFR genotypes (p ≤ 0.0001) and was lower in subgroups carrying the most impaired enzyme with respect to patients carrying the conservative MTHFR (p ≤ 0.0001, p ≤ 0.05, respectively). Consistently, OS patients carried the most dysfunctional MTHFR genotypes, whereas SI patients the least ones. Conclusions: A low L-Arg/ADMA ratio correlates with impaired activity of MTHFR and with the jeopardized IAS phenotype along a severity spectrum encompassing OS, PFO with long/tight tunnel, PFO with short/large tunnel, and SI. This infers that genetic MTHFR defects may underlie endothelial dysfunction-related IAS abnormalities, and predispose to a cryptogenic stroke. Our findings emphasize the role of the L-Arg/ADMA ratio as a reliable marker of stroke susceptibility in carriers of IAS abnormalities, and suggest its potential use both as a diagnostic tool and as a decision aid for therapy.

Choosing the right therapy for a patient with asymptomatic carotid stenosis

Introduction: Most patients with asymptomatic carotid stenosis (ACS) now have a lower risk with intensive medical therapy than with stenting (CAS) or endarterectomy (CEA); the annual risk of stroke or death with intensive medical therapy is ~ 0.5%, vs. a periprocedural risk with CAS of ~ 2.5-4.1% with CAS, and ~ 1.4-1.8% with CEA. The excess risk of CAS is greater in older patients.Areas covered: Discussed are the need for intensive medical therapy, the nature of intensive medical therapy, approaches to identifying the few patients with ACS who could benefit from CEA or CAS, and which patients would be better suited to CEA vs. CAS.Expert opinion: All patients with ACS are at high risk of cardiovascular events, soshould receive intensive medical therapy including lifestyle modification, intensive lipid-lowering, B vitamins to lower homocysteine (using methylcobalamin rather than cyanocobalamin), and appropriate antithrombotic therapy. High-risk patients who could benefit from intervention can be identified by clinical and imaging features including transcranial Doppler embolus detection, ulceration, intraplaque hemorrhage, reduced cerebrovascular reserve, plaque echolucency, silent infarction on brain imaging, and progression of stenosis. Most patients whose risk of stroke warrants intervention would be better treated with CEA than with CAS.

Carotid Intima-Media Thickness and the Risk of First Stroke in Patients With Hypertension

Background and Purpose—

This study aimed to investigate the association between mean carotid intima-media thickness (cIMT) and the risk of first stroke and examine any possible effect modifiers in patients with hypertension.

Methods—

A total of 11 547 hypertensive participants without history of stroke from the CSPPT (China Stroke Primary Prevention Trial) were included in this analysis. The primary outcome was first stroke.

Results—

Over a median follow-up of 4.4 years, 726 first strokes were identified, of which 631 were ischemic, and 90 were hemorrhagic. A per SD increase in mean cIMT was positively associated with the risk of first stroke (hazard ratio [HR], 1.11 [95% CI, 1.03–1.20]), and first ischemic stroke (HR, 1.10 [95% CI, 1.01–1.20]). Moreover, when cIMT was categorized in quartiles, the higher risks of first stroke (HR, 1.31 [95% CI, 1.06–1.61]) and first hemorrhagic stroke (HR, 2.25 [95% CI, 1.11–4.58]) were found in participants in quartile 2 to 4 (≥0.66 mm), compared with those in quartile 1 (<0.66 mm). More importantly, the cIMT-first stroke association was significantly stronger in participants with higher mean arterial pressure (≥109.3 [quintile 5] versus <109.3 mm Hg, P -interaction=0.024) or diastolic blood pressure levels (≥90.7 [quintile 5] versus <90.7 mm Hg, P -interaction=0.009).

Conclusions—

There was a significant positive association between baseline cIMT and the risk of first stroke in patients with hypertension. This association was even stronger among those with higher mean arterial pressure or diastolic blood pressure levels.

Interaction of serum vitamin B12 and folate with MTHFR genotypes on risk of ischemic stroke

OBJECTIVE

We evaluated the interaction of serum folate and vitamin B₁₂ with methylenetetrahydrofolate reductase (MTHFR) C677T genotypes on the risk of first ischemic stroke and on the efficacy of folic acid treatment in prevention of first ischemic stroke.

METHODS

A total of 20,702 hypertensive adults were randomized to a double-blind treatment of daily enalapril 10 mg and folic acid 0.8 mg or enalapril 10 mg alone. Participants were followed up every 3 months.

RESULTS

Median values of folate and B₁₂ concentrations at baseline were 8.1 ng/mL and 280.2 pmol/L, respectively. Over a median of 4.5 years, among those not receiving folic acid, participants with baseline serum B₁₂ or serum folate above the median had a significantly lower risk of first ischemic stroke (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.57-0.96), especially in those with MTHFR 677 CC genotype (wild-type) (HR, 0.49; 95% CI, 0.31-0.78). Folic acid treatment significantly reduced the risk of first ischemic stroke in participants with both folate and B₁₂ below the median (2.3% in enalapril-folic acid group vs 3.6% in enalapril-only group; HR, 0.62; 95% CI, 0.46-0.86), particularly in MTHFR 677 CC carriers (1.6% vs 4.9%; HR, 0.24; 95% CI, 0.11-0.55). However, TT homozygotes responded better with both folate and B₁₂ levels above the median (HR, 0.28; 95% CI, 0.10-0.75).

CONCLUSIONS

The risk of first ischemic stroke was significantly higher in hypertensive patients with low levels of both folate and B₁₂. Effect of folic acid treatment was greatest in patients with low folate and B₁₂ with the CC genotype, and with high folate and B₁₂ with the TT genotype.

[Primary Prevention of Acute Stroke]

Primary Prevention of Acute Stroke Abstract. Strokes are frequent. Vascular risk factors are increasing the stroke risk. Most vascular risk factors are treatable. Their therapy is important in the primary prevention of stroke. According to the INTERSTROKE study, arterial hypertension, inactivity, overweight, dyslipidemia, smoking, unhealthy diet, cardiac pathologies such as major arrhythmia, diabetes mellitus, stress/depression and overconsumption of alcohol are the most important treatable vascular risk factors. In this article, we will also report on at present less well known treatable vascular risk factors such as sleep apnea, atheromatosis of the aortic arch and of arteries supplying the brain, migraine with aura and chronic inflammatory disorders and infections.

Estimated Stroke-Free Survival of Folic Acid Therapy for Hypertensive Adults: Projection Based on the CSPPT

The CSPPT (China Stroke Primary Prevention Trial) demonstrated a significant risk reduction of first stroke in hypertensive patients treated with enalapril plus folic acid compared with those with enalapril alone, but the lifetime stroke-free survival associated with the treatment is unknown. By establishing adjusted models for competing risks and an age-based time scale using data from 19 053 participants of the CSPPT, we estimated lifetime incremental stroke-free survival for enalapril-folic acid versus enalapril alone. Compared with enalapril alone, the enalapril plus folic acid treatment projected a mean lifetime stroke-free survival gain of 1.75 months, with an interquartile range from 0.73 to 2.39 months and the maximum gain up to 12.95 months. Subgroup analyses showed greater gain in stroke-free survival in younger, male patients, those with lower baseline folate levels, higher baseline systolic blood pressure, higher baseline total cholesterol and blood glucose, and with MTHFR (methylenetetrahydrofolate reductase) C677T CT or TT genotype. Overall, besides significant benefit in certain subgroups, enalapril plus folic acid treatment for hypertensive patients is associated with a modest gain in lifetime stroke-free survival, compared with enalapril alone.

A Randomized Pilot Trial to Evaluate the Bioavailability of Natural versus Synthetic Vitamin B Complexes in Healthy Humans and Their Effects on Homocysteine, Oxidative Stress, and Antioxidant Levels

The vitamin B complex comprises 8 different water-soluble constituents that humans must sequester from the diet. This pilot study compared natural versus synthetic vitamin B complexes for their bioavailability, accumulation, and their impact on antioxidants, homocysteine levels, and oxidative stress. We conducted a double-blind randomized clinical trial with thirty healthy participants. They were randomly assigned to group N (natural) and group S (synthetic). Vitamin B was ingested daily for 6 weeks in the range of about 2.5 times above the recommended daily allowance. Blood samples were taken at baseline, 1.5 h, 4 h, 7 h (diurnal), 6 w (discontinuation of supplements), and 8 w (washout). Blood levels of thiamine (B₁), riboflavin (B₂), pyridoxine (B₆), folic acid (B₉), cobalamin (B₁₂), homocysteine, total antioxidants, peroxidase activity, polyphenols, and total peroxides were determined. Compared to initial values, serum levels of each B vitamin increased at the end of the supplementation period: i.e., B₁ (+23% N; +27% S), B₂ (+14% N; +13% S), B₆ (+101% N; +101% S), B₉ (+86% N; +153% S), and B₁₂ (+16% N) (p < 0.05). Homocysteine (-13% N) decreased, while peroxidase activity (+41% S) and antioxidant capacity increased (+26% N). Short-term effects were already observed after 1.5 h for B₉ (+238% N; +246% S) and after 4 h for vitamin B₂ (+7% N; +8% S), B₆ (+59% N; +51% S), and peroxidase activity (+58% N; +58% S). During the washout period, serum levels of B vitamins decreased except for thiamine and peroxidase activity, which increased further. This clinical pilot study revealed comparable bioavailability for both natural and synthetic B vitamins but did not show statistically noticeable differences between groups despite some favourable tendencies within the natural vitamin group, i.e., sustained effects for cobalamin and endogenous peroxidase activity and a decrease in homocysteine and oxidative stress levels.

Plasma selenium levels and risk of new-onset diabetes in hypertensive adults

OBJECTIVE

The association between plasma selenium and new-onset diabetes in hypertensive adults is still unclear. We aimed to evaluate the relationship of baseline plasma selenium with new-onset diabetes and examine possible effect modifiers in a post-hoc analysis of the China Stroke Primary Prevention Trial (CSPPT).

METHODS

A total of 2367 hypertensive, non-diabetic patients with plasma selenium measurements at baseline were included. The primary outcome was new-onset diabetes, defined as physician-diagnosed diabetes or use of glucose-lowering drugs during the follow-up period, or fasting glucose (FG) ≥126.0 mg/dL at the exit visit.

RESULTS

At baseline, higher FG levels were found among participants with plasma selenium in quartile 4 (≥94.8 μg/L) (β, 1.64 mg/dL; 95%CI: 0.54, 2.73) compared to those in quartiles 1-3. During a median follow-up duration of 4.5 years, new-onset diabetes occurred in 270 (11.4%) participants. Graphic plot showed a positive association between baseline selenium levels and risk of new-onset diabetes. This was further confirmed by adjusted regression analyses; the odds ratios (OR) for new-onset diabetes comparing quartile 4 (≥94.8 μg/L) to quartiles 1-3 was 1.36 (95%CI: 1.01, 1.83). No clear trend was evident across quartiles 1-3.

CONCLUSIONS

Our data suggest that high plasma selenium (≥94.8 μg/L) was associated with increased risk of new-onset diabetes in hypertensive patients.

Positive association between baseline brachial-ankle pulse wave velocity and the risk of new-onset diabetes in hypertensive patients

Background

There is no clearly defined temporal relationship between arterial stiffness and diabetes. We aimed to investigate the prospective association between baseline brachial–ankle pulse wave velocity (baPWV) and the risk of new-onset diabetes during follow-up, and examined whether there were effect modifiers, in hypertensive patients.

Methods

We included 2429 hypertensive patients with all the pertinent data but without diabetes at the baseline, who were part of the China Stroke Primary Prevention Trial (CSPPT), a randomized, double-blind, actively controlled trial conducted in 32 communities in Anhui and Jiangsu provinces in China. The primary outcome was new-onset diabetes, defined as physician-diagnosed diabetes or use of glucose-lowering drugs during follow-up, or fasting glucose (FG) ≥ 126.0 mg/dL at the exit visit.

Results

During a median follow-up duration of 4.5 years, 287 (11.8%) participants developed diabetes. There was a significant positive association between baseline baPWV and the risk of new-onset diabetes (per SD increment; OR, 1.33; 95% CI 1.13, 1.56). Consistently, when baPWV was assessed as quartiles, a significantly higher risk of new-onset diabetes was found in participants in quartiles 2–4 (≥ 15.9 m/s; OR, 1.80; 95% CI 1.22, 2.65) compared with those in quartile 1 (< 15.9 m/s). The positive association was consistent in participants with (per SD increment; OR, 1.29; 95% CI 1.06, 1.56) or without (per SD increment; OR, 1.40; 95% CI 1.15, 1.71) impaired fasting glucose (IFG, FG ≥ 100.8 and < 126.0 mg/dL, P-interaction = 0.486).

Conclusions

In this sample of hypertensive patients, we found a significant positive association between baseline baPWV and the risk of new-onset diabetes.

Clinical trial registration Trial registration: NCT00794885 (clinicaltrials.gov). Retrospectively registered November 20, 2008

Lack of association between serum homocysteine level and middle cerebral artery stenosis

OBJECTIVES

Lowering homocysteine (HCY) has beneficial effects on vascular events in primary prevention but not in secondary prevention. Research on serum HCY level and middle cerebral artery (MCA) stenosis is lacking. The purpose of the study was to determine the association between these factors and provide more evidence for the prevention of ischemic stroke.

METHODS

A total of 412 patients (35-93 years old) in the Neurology Department were recruited. Data of clinical and biochemical vascular risk factors were collected. MCA stenosis, including M1, M2, and M3, was determined by brain magnetic resonance angiography (MRA) and classified into stenosis or no stenosis. The differences and associations were analyzed by relevant statistical methods.

RESULTS

There was no significant difference (p = 0.325) in HCY levels between the MCA stenosis and no stenosis groups at baseline. Logistic regression analysis demonstrated that there was no significant association between HCY levels and MCA stenosis (p = 0.447). After the two groups were matched for age and sex, there was still no difference (p = 0.540 for males and 0.061 for females) or association (p = 0.709 for males and 0.098 for females). In addition, we found that ischemic stroke was more prevalent in the MCA stenosis group and uric acid was higher in males with MCA stenosis.

CONCLUSIONS

The study indicates a lack of association between serum HCY level and MCA stenosis, which may partially explain the negative results of secondary prevention clinical trials focused on lowering serum HCY level. Future studies on HCY reduction should focus more on primary prevention of ischemic stroke.

Association of plasma retinol levels with incident cancer risk in Chinese hypertensive adults: a nested case-control study

We aimed to investigate the association between plasma retinol and incident cancer among Chinese hypertensive adults. We conducted a nested case-control study, including 231 patients with incident cancer and 231 matched controls during a median 4·5-year follow-up of the China Stroke Primary Prevention Trial. There was a significant, inverse association between retinol levels and digestive system cancer (per 10 μg/dl increases: OR 0·79; 95 % CI 0·69, 0·91). When compared with participants in the first quartile of retinol (< 52·3 μg/dl), a significantly lower cancer risk was found in participants in quartile 2-4 ( ≥ 52·3 μg/dl: OR 0·31; 95 % CI 0·13, 0·71). However, there was a U-shaped association between retinol levels and non-digestive system cancers where the risk of cancers decreased (although not significantly) with each increment of plasma retinol (per 10 μg/dl increases: OR 0·89; 95 % CI 0·60, 1·31) in participants with retinol < 68·2 μg/dl, and then increased significantly with retinol (per 10 μg/dl increase: OR 1·65; 95 % CI 1·12, 2·44) in participants with retinol ≥ 68·2 μg/dl. In conclusion, there was a significant inverse dose-response association between plasma retinol and the risk of digestive system cancers. However, a U-shaped association was observed between plasma retinol and the risk of non-digestive cancers (with a turning point approximately 68·2 μg/dl).

Nutrition and Risk of Stroke

Nutrition is far more important in stroke risk than most physcians suppose. Healthy lifestyle choices reduce the risk of stroke by ~80%, and of the factors that increase the risk of stroke, the worst is diet: only ~0.1% of Americans consume a healthy diet, and only 8.3% consume a somewhat healthy diet. The situation is probably not much better in most other countries. A Cretan Mediterranean diet, high in olive oil, whole grains, fruits, vegetables and legumes, and low in cholesterol and saturated fat, can reduce stroke by 40% or more in high-risk patients. The role of the intestinal microbiome in cardiovascular risk is emerging; high levels of toxic metabolites produced by intestinal bacteria from meat (particularly red meat) and egg yolk are renally excreted. Patients with renal impairment, including the elderly, should limit red meat and avoid egg yolk, as should other patients at high risk of stroke. Salt intake should be limited to 2–3 grams per day. Metabolic B12 deficiency is common and usually missed. It has serious neurological consequences, including an increase in the risk of stroke. It now clear that B vitamins to lower homocysteine reduce the risk of stroke, but we should probably be using methylcobalamin instead of cyanocobalamin.

Plasma retinol and the risk of first stroke in hypertensive adults: a nested case-control study

Background

Identification of novel risk factors is needed to further lower stroke risk. Data concerning the association between plasma retinol concentrations and the risk of stroke are limited.

Objectives

We aimed to evaluate the effect of plasma retinol on the risk of first stroke and to examine any possible effect modifiers in hypertensive patients.

Methods

The study sample population was drawn from the China Stroke Primary Prevention Trial (CSPPT), using a nested case-control design, including 620 cases with first stroke and 620 matched controls. In the CSPPT, a total of 20,702 hypertensive patients were randomly assigned to a double-blind, daily treatment with either 10 mg enalapril and 0.8 mg folic acid or 10 mg enalapril alone. The median treatment duration was 4.5 y.

Results

There was a significant inverse association between plasma retinol and the risk of first stroke (per 10-μg/dL increment; OR: 0.92; 95% CI: 0.86, 0.97) and first ischemic stroke (OR: 0.92; 95% CI: 0.86, 0.98). When retinol was assessed as quartiles, significantly lower risks of first stroke (OR: 0.64; 95% CI: 0.46, 0.88) and first ischemic stroke (OR: 0.67; 95% CI: 0.46, 0.96) were found in participants in quartiles 2-4 compared with those in quartile 1. Furthermore, a stronger inverse association between plasma retinol and first stroke was observed in participants with baseline total homocysteine (<10 compared with ≥10 μmol/L; P-interaction = 0.049). However, plasma retinol had no significant effect on first hemorrhagic stroke (per 10-μg/dL increment; OR: 0.98; 95% CI: 0.79, 1.18).

Conclusions

Our data showed a significant inverse association between plasma retinol and the risk of first stroke among Chinese hypertensive adults. This study was registered at clinicaltrials.gov as NCT00794885.

Vitamin B 12 deficiency and hyperhomocysteinaemia in outpatients with stroke or transient ischaemic attack: a cohort study at an academic medical centre

OBJECTIVE

We sought to assess the current magnitude of the opportunity for secondary stroke prevention with B vitamins.

DESIGN

A cohort study.

SETTING

The Urgent TIA (Transient Ischaemic Attack) Clinic at an academic medical centre.

MAIN OUTCOME MEASURES

We assessed the prevalence of biochemical vitamin B12 deficiency (B12Def, serum B12 <156 pmol/L), hyperhomocysteinaemia (HHcy; plasma total homocysteine [tHcy] >14 µmol/L) and metabolic B12 deficiency (MetB12Def, serum B12 <258 pmol/L and HHcy) between 2002 and 2017, by age group and by stroke subtype.

RESULTS

Data were available in 4055 patients. B12Def was present in 8.2% of patients overall; it declined from 10.9% of patients referred before 2009 to 5.4% thereafter (p=0.0001). MetB12Def was present in 10.6% of patients, and HHcy was present in 19.1% of patients. Among the patients aged ≥80 years, MetB12Def was present in 18.1% and HHcy in 35%. Among the 3410 patients whose stroke subtype was determined, HHcy was present in 18.4% of patients: 23.3% of large artery atherosclerosis, 18.1% of cardioembolic, 16.3% of small vessel disease, 10.8% of other unusual aetiologies and 13.6% of undetermined subtypes (p=0.0001).

CONCLUSIONS

Despite a decline in our referral area since 2009, B12Def, MetB12Def and HHcy remain common in patients with stroke/TIA. Because these conditions are easily treated and have serious consequences, all patients with stroke/TIA should have their serum B12 and tHcy measured.

Hyperhomocysteinemia is an independent risk factor of atherosclerosis in patients with metabolic syndrome

BACKGROUND

Metabolic syndrome (MetS) is a clinical condition potentially promoting the development of atherosclerotic disease. To date, the clinical impact of elevated serum homocysteine (Hcy) levels in MetS is still under discussion. The aim of this cross sectional study was to evaluate the relationship between MetS and hyperhomocysteinemia and the potential role of Hcy in the pathogenesis of atherosclerotic complications of MetS.

METHODS

We recruited 300 outpatients with MetS. All patients underwent a medical history collection, physical examination, blood sampling and carotid ultrasound echo-color Doppler. According to Hcy levels, MetS patients were divided into two groups: "normal" (< 10.7 μmol/l; n = 140, group 1) and "high" Hcy (≥ 10.7 μmol/l; n = 160, group 2). Comparisons between groups were made by Student's t-test or Chi-square test. The effects of potential covariates on group differences were evaluated by general linear models. The relationships between continuous variables were assessed by simple or multiple correlation and by linear regression. Multiple regression models were built to evaluate the effects of Hcy, together with other potential risk factors, on carotid atherosclerosis.

RESULTS

Patients with high Hcy were predominantly male and slightly older than group 1 patients. Smokers and non-smokers exhibited similar Hcy levels, nor was a statistical relationship between pack-years and Hcy observed. Group 2 showed lower levels of folic acid, vitamin D, high density lipoprotein (HDL)-cholesterol and glomerular filtration rate (e-GFR) than group 1, but higher levels of C-peptide, uric acid and triglycerides. In all patients, Hcy was positively correlated with C-peptide and uric acid and negatively with folic acid and e-GFR. Intima-media thickness (IMT) and carotid stenosis degree were significantly higher in patients with high Hcy and a positive relationship between Hcy and both IMT and carotid stenosis was detected in all patients. Finally, Hcy atherogenic effects were independent of other well-known atherosclerosis risk factors.

CONCLUSIONS

Our results highlight a link between MetS and hyperhomocysteinemia and a direct effect of Hcy on atherogenic process during MetS. Early correction of folic acid levels may contribute to prevent cardiovascular complications in MetS patients.

Effect of long-term low-dose folic acid supplementation on degree of total homocysteine-lowering: major effect modifiers

We sought to examine the potential modifiers in the association between long-term low-dose folic acid supplementation and the reduction of serum total homocysteine (tHcy) among hypertensive patients, using data from the China Stroke Primary Prevention Trial (CSPPT). This analysis included 16 867 participants who had complete data on tHcy measurements at both the baseline and exit visit. After a median treatment period of 4·5 years, folic acid treatment significantly reduced the tHcy levels by 1·6 μmol/l (95 % CI 1·4, 1·8). More importantly, after adjustment for baseline tHcy and other important covariates, a greater degree of tHcy reduction was observed in certain subgroups: males, the methylenetetrahydrofolate reductase (MTHFR) 677TT genotype, higher baseline tHcy levels (≥12·5 (median) v. <12·5 μmol/l), lower folate levels (<8·0 (median) v. ≥8·0 ng/ml), estimated glomerular filtration rate (eGFR) <60 ml/min per 1·73 m2 (v. 60–<90 and ≥90 ml/min per 1·73 m2), ever smokers and concomitant use of diuretics (P for all interactions <0·05). The degree of tHcy reduction associated with long-term folic acid supplementation can be significantly affected by sex, MTHFR C677T genotypes, baseline folate, tHcy, eGFR levels and smoking status.

Folic acid modulates VPO1 DNA methylation levels and alleviates oxidative stress-induced apoptosis in vivo and in vitro

Endothelial cell injury and apoptosis play a primary role in the pathogenesis of atherosclerosis. Moreover, accumulating evidence indicates that oxidative injury is an important risk factor for endothelial cell damage. In addition, low folate levels are considered a contributing factor to promotion of vascular disease because of the deregulation of DNA methylation. We aimed to investigate the effects of folic acid on injuries induced by oxidative stress that occur via an epigenetic gene silencing mechanism in ApoE knockout mice fed a high-fat diet and in human umbilical vein endothelial cells treated with oxidized low-density lipoprotein (ox-LDL). We assessed how folic acid influenced the levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG, an oxidative DNA damage marker) and cellular apoptosis in in vivo and in vitro models. Furthermore, we analyzed DNA methyltransferase (DNMT) activity, vascular peroxidase 1 (VPO1) expression, and promoter methylation in human umbilical vein endothelial cells. Our data showed that folic acid reduced 8-OHdG levels and decreased apoptosis in the aortic tissue of ApoE^−/− mice. Likewise, our in vitro experiments showed that folic acid protects against endothelial dysfunction induced by ox-LDL by reducing reactive oxygen species (ROS)-derived oxidative injuries, 8-OHdG content, and the apoptosis ratio. Importantly, this effect was indirectly caused by increased DNMT activity and altered DNA methylation at VPO1 promoters, as well as changes in the abundance of VPO1 expression. Collectively, we conclude that folic acid supplementation may prevent oxidative stress-induced apoptosis and suppresses ROS levels through downregulating VPO1 as a consequence of changes in DNA methylation, which may contribute to beneficial effects on endothelial function.

•

Folic acid reduces oxidative stress-induced injuries in atherosclerosis.

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Folic acid decreases 8-OHdG levels and apoptosis in vivo and in vitro.

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Folic acid supplementation increases DNMT levels and regulates VPO1 expression.

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VPO1 expression is modulated by epigenetic silencing via promoter methylation.

Effect of Smoking and Folate Levels on the Efficacy of Folic Acid Therapy in Prevention of Stroke in Hypertensive Men

BACKGROUND AND PURPOSE

We aimed to examine whether the efficacy of folic acid therapy in the primary prevention of stroke is jointly affected by smoking status and baseline folate levels in a male population in a post hoc analysis of the CSPPT (China Stroke Primary Prevention Trial).

METHODS

Eligible participants of the CSPPT were randomly assigned to a double-blind daily treatment of a combined enalapril 10-mg and folic acid 0.8-mg tablet or an enalapril 10-mg tablet alone. In total, 8384 male participants of the CSPPT were included in the current analyses. The primary outcome was first stroke.

RESULTS

The median treatment duration was 4.5 years. In the enalapril-alone group, the first stroke risk varied by baseline folate levels and smoking status (never versus ever). Specifically, there was an inverse association between folate levels and first stroke in never smokers (P for linear trend=0.043). However, no such association was found in ever smokers. A test for interaction between baseline folate levels and smoking status on first stroke was significant (P=0.045). In the total sample, folic acid therapy significantly reduced the risk of first stroke in never smokers with folate deficiency (hazard risk, 0.36; 95% confidence interval, 0.16-0.83) and in ever smokers with normal folate levels (hazard risk, 0.69; 95% confidence interval, 0.48-0.99).

CONCLUSIONS

Baseline folate levels and smoking status can interactively affect the risk of first stroke. Our data suggest that compared with never smokers, ever smokers may require a higher dosage of folic acid to achieve a greater beneficial effect on stroke. Our findings need to be confirmed by future randomized trials.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00794885.

Safety of folic acid

There is a large body of literature demonstrating the efficacy of maternal folic acid intake in preventing birth defects, as well as investigations into potential adverse consequences of consuming folic acid above the upper intake level (UL). Recently, two authoritative bodies convened expert panels to assess risks from high intakes of folic acid: the U.S. National Toxicology Program and the UK Scientific Advisory Committee on Nutrition. Overall, the totality of the evidence examined by these panels, as well as studies published since the release of their reports, have not established risks for adverse consequences resulting from existing mandatory folic acid fortification programs that have been implemented in many countries. Current folic acid fortification programs have been shown to support public health in populations, and the exposure levels are informed by and adherent to the precautionary principle. Additional research is needed to assess the health effects of folic acid supplement use when the current upper limit for folic acid is exceeded.

Homocysteine Lowering with B Vitamins for Stroke Prevention—A History

Early trials of B vitamin therapy to lower plasma total homocysteine (tHcy) reported no reduction of stroke with high doses of folate/B6 and cyanocobalamin 400–1,000 μg daily. In patients with diabetic nephropathy, folate/B6 and cyanocobalamin 1,000 μg daily accelerated the decline of renal function and doubled cardiovascular events. Patients with renal failure have high cyanide levels. The French SUpplementation with FOlate, vitamin B6 and B12 and/or OMega-3 fatty acids (Su.Fol.OM3) trial—with the best renal function of the early trials and the lowest dose of cyanocobalamin (20 μg daily)—reported a 43% reduction of stroke. Then the China Stroke Primary Prevention Trial (CSPPT) reported that folic acid alone reduced stroke and was beneficial even in patients with impaired renal function. Patient-level data from the Vitamin Intervention to Prevent Stroke (VISP) and VITAmins TO Prevent Stroke (VITATOPS) trials and meta-analyses stratified by renal function and dose of cyanocobalamin confirmed that harm from cyanocobalamin among participants with renal impairment obscured the benefit of B vitamins in the early trials. It does seem that B vitamins reduce the risk of stroke. In the era of folate fortification, B12 is the main nutritional determinant of tHcy, and metabolic B12 deficiency is very common and usually missed. Therefore, folate alone is not the optimal way to lower tHcy: the use of folate (and possibly B6) with methylcobalamin or oxocobalamin should be considered.

Homocysteine in non-valvular atrial fibrillation: Role and clinical implications

Atrial fibrillation (AF), the most common sustained arrhythmia, is associated with a series of adverse complications that cause so-called AF socioeconomic burden. Apart from the classical risk factors, it seems to be novel factors that increase the risk of AF and AF-related stroke. Recently, more and more evidence has well documented the close relationships between homocysteine (Hcy) and AF. As a well-known marker for pro-oxidation and pro-inflammation, Hcy plays an important role in a number of vascular diseases having strong association with AF. This review will discuss the expression of Hcy and its association with ischemic stroke in AF patients especially for elderly patients, and the role and clinical implications of Hcy in the thromboembolic events and rhythm outcome in AF patients. The possible mechanisms linking elevated Hcy and cardiovascular events in AF patients will also be addressed, including oxidative stress, inflammatory response, atrial remodeling, etc.

B vitamins in stroke prevention: time to reconsider

B vitamin therapy lowers plasma total homocysteine concentrations, and might be a beneficial intervention for stroke prevention; however, cyanocobalamin (a form of vitamin B12) can accelerate decline in renal function and increase the risk of cardiovascular events in patients with impaired renal function. Although early trials did not show benefit in reduction of stroke, these results might have been due to harm in participants with impaired renal function. In patients with diabetic nephropathy, cyanocobalamin is harmful, whereas B vitamins appear to reduce cardiovascular events in study participants with normal renal function. Our meta-analysis of individual patient data from two large trials of B vitamin therapy (VISP and VITATOPS) indicates that patients with impaired renal function who are exposed to high-dose cyanocobalamin do not benefit from therapy with B vitamins for the prevention of stroke (risk ratio 1·04, 95% CI 0·84-1·27), however, patients with normal renal function who are not exposed to high-dose cyanocobalamin benefit significantly from this treatment (0.78, 0·67-0·90; interaction p=0·03). The potential benefits of B vitamin therapy with folic acid and methylcobalamin or hydroxycobalamin, instead of cyanocobalamin, to lower homocysteine concentrations in people at high risk of stroke warrant further investigation.

Homocysteine-lowering interventions for preventing cardiovascular events

BACKGROUND

Cardiovascular disease, which includes coronary artery disease, stroke and peripheral vascular disease, is a leading cause of death worldwide. Homocysteine is an amino acid with biological functions in methionine metabolism. A postulated risk factor for cardiovascular disease is an elevated circulating total homocysteine level. The impact of homocysteine-lowering interventions, given to patients in the form of vitamins B6, B9 or B12 supplements, on cardiovascular events has been investigated. This is an update of a review previously published in 2009, 2013, and 2015.

OBJECTIVES

To determine whether homocysteine-lowering interventions, provided to patients with and without pre-existing cardiovascular disease are effective in preventing cardiovascular events, as well as reducing all-cause mortality, and to evaluate their safety.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 5), MEDLINE (1946 to 1 June 2017), Embase (1980 to 2017 week 22) and LILACS (1986 to 1 June 2017). We also searched Web of Science (1970 to 1 June 2017). We handsearched the reference lists of included papers. We also contacted researchers in the field. There was no language restriction in the search.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of homocysteine-lowering interventions for preventing cardiovascular events with a follow-up period of one year or longer. We considered myocardial infarction and stroke as the primary outcomes. We excluded studies in patients with end-stage renal disease.

DATA COLLECTION AND ANALYSIS

We performed study selection, 'Risk of bias' assessment and data extraction in duplicate. We estimated risk ratios (RR) for dichotomous outcomes. We calculated the number needed to treat for an additional beneficial outcome (NNTB). We measured statistical heterogeneity using the I2 statistic. We used a random-effects model. We conducted trial sequential analyses, Bayes factor, and fragility indices where appropriate.

MAIN RESULTS

In this third update, we identified three new randomised controlled trials, for a total of 15 randomised controlled trials involving 71,422 participants. Nine trials (60%) had low risk of bias, length of follow-up ranged from one to 7.3 years. Compared with placebo, there were no differences in effects of homocysteine-lowering interventions on myocardial infarction (homocysteine-lowering = 7.1% versus placebo = 6.0%; RR 1.02, 95% confidence interval (CI) 0.95 to 1.10, I2 = 0%, 12 trials; N = 46,699; Bayes factor 1.04, high-quality evidence), death from any cause (homocysteine-lowering = 11.7% versus placebo = 12.3%, RR 1.01, 95% CI 0.96 to 1.06, I2 = 0%, 11 trials, N = 44,817; Bayes factor = 1.05, high-quality evidence), or serious adverse events (homocysteine-lowering = 8.3% versus comparator = 8.5%, RR 1.07, 95% CI 1.00 to 1.14, I2 = 0%, eight trials, N = 35,788; high-quality evidence). Compared with placebo, homocysteine-lowering interventions were associated with reduced stroke outcome (homocysteine-lowering = 4.3% versus comparator = 5.1%, RR 0.90, 95% CI 0.82 to 0.99, I2 = 8%, 10 trials, N = 44,224; high-quality evidence). Compared with low doses, there were uncertain effects of high doses of homocysteine-lowering interventions on stroke (high = 10.8% versus low = 11.2%, RR 0.90, 95% CI 0.66 to 1.22, I2 = 72%, two trials, N = 3929; very low-quality evidence).We found no evidence of publication bias.

AUTHORS' CONCLUSIONS

In this third update of the Cochrane review, there were no differences in effects of homocysteine-lowering interventions in the form of supplements of vitamins B6, B9 or B12 given alone or in combination comparing with placebo on myocardial infarction, death from any cause or adverse events. In terms of stroke, this review found a small difference in effect favouring to homocysteine-lowering interventions in the form of supplements of vitamins B6, B9 or B12 given alone or in combination comparing with placebo.There were uncertain effects of enalapril plus folic acid compared with enalapril on stroke; approximately 143 (95% CI 85 to 428) people would need to be treated for 5.4 years to prevent 1 stroke, this evidence emerged from one mega-trial.Trial sequential analyses showed that additional trials are unlikely to increase the certainty about the findings of this issue regarding homocysteine-lowering interventions versus placebo. There is a need for additional trials comparing homocysteine-lowering interventions combined with antihypertensive medication versus antihypertensive medication, and homocysteine-lowering interventions at high doses versus homocysteine-lowering interventions at low doses. Potential trials should be large and co-operative.