Alcohol drinking and risk of hospitalization for ischemic stroke

Chronic Low-Dose Alcohol Consumption Promotes Cerebral Angiogenesis in Mice

Chronic alcohol consumption dose-dependently affects the incidence and prognosis of ischemic stroke. We determined the influence of chronic alcohol consumption on cerebral angiogenesis under physiological conditions and following ischemic stroke. In in vitro studies, acute exposure to low-concentration ethanol significantly increased angiogenic capability and upregulated vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR2) in C57BL/6J mouse brain microvascular endothelial cells (MBMVECs). The increased angiogenic capability was abolished in the presence of a VEGFR2 inhibitor. In addition, the increased angiogenic capability and upregulated VEGF-A and VEGFR2 remained in chronically low-concentration ethanol-exposed MBMVECs. In in vivo studies, 8-week gavage feeding with low-dose ethanol significantly increased vessel density and vessel branches and upregulated VEGF-A and VEGFR2 in the cerebral cortex under physiological conditions. Furthermore, vessel density, vessel branches, and expression of VEGF-A and VEGFR2 in the peri-infarct cortex were significantly greater in low-dose ethanol-fed mice at 72 h of reperfusion. Although low-dose ethanol did not alter cerebral vasoreactivity and regional cerebral blood flow (rCBF) either before or during ischemia, it significantly augmented post-ischemic hyperemia during reperfusion. In contrast, exposure to high-concentration ethanol and 8-week gavage feeding with high-dose ethanol only had a mild inhibitory effect on angiogenic capability and cerebral angiogenesis, respectively. We conclude that heavy alcohol consumption may not dramatically alter cerebral angiogenesis, whereas light alcohol consumption significantly promotes cerebral angiogenesis.

Chronic Low-Dose Alcohol Consumption Attenuates Post-Ischemic Inflammation via PPARγ in Mice

Ischemic stroke is one of the leading causes of death and permanent disability in adults. Recently, we found that light alcohol consumption (LAC) suppresses post-ischemic inflammatory response, which plays an important role in ischemic brain damage. Our goal was to determine the role of peroxisome proliferator-activated receptor-gamma (PPARγ) in the anti-inflammatory effect of LAC against transient focal cerebral ischemia. In in vivo study, male C57BL/6J wild type (WT) and endothelial-specific conditional PPARγ knockout mice were gavage fed with 0.7 g/kg/day ethanol or volume-matched water daily for 8 weeks. From the 7th week, 3 mg/kg/day GW9662 (a selective PPARγ antagonist) was intraperitoneally given for two weeks. Cerebral ischemia/reperfusion (I/R) injury and expression of manganese superoxide dismutase (MnSOD) and adhesion molecules, neutrophil infiltration, and microglial activation in the cerebral cortex before and following a 90 min unilateral middle cerebral artery occlusion (MCAO)/24 h reperfusion were evaluated. In in vitro study, the impact of chronic alcohol exposure on expression of PPARγ and MnSOD in C57BL/6J mouse brain microvascular endothelial cells (MBMVECs) was measured. PPARγ and MnSOD were significantly upregulated in the cerebral cortex of ethanol-fed WT mice and low-concentration ethanol-exposed C57BL/6J MBMVECs. GW9662 significantly inhibited alcohol-induced upregulation of MnSOD. Eight-week ethanol feeding significantly reduced cerebral I/R injury and alleviated the post-ischemic inflammatory response (upregulation of intercellular adhesion molecule-1 (ICAM-1) and E-selectin, microglial activation, and neutrophil infiltration). Treatment with GW9662 and endothelial-specific conditional knockout of PPARγ did not alter cerebral I/R injury and the inflammatory response in the control mice but abolish the neuroprotective effect in ethanol-fed mice. In addition, GW9662 and endothelial-specific conditional knockout of PPARγ diminished the inhibitory effect of LAC on the post-ischemic expression of adhesion molecules and neutrophil infiltration. Our findings suggest that LAC may protect against cerebral I/R injury by suppressing the post-ischemic inflammation via activation of PPARγ.

Study of Symptomatic vs. Silent Brain Infarctions on MRI in Elderly Subjects

Brain infarctions are closely associated with future risk of stroke and dementia. Our goal was to report (i) frequency and characteristics that differentiate symptomatic vs. silent brain infarctions (SBI) on MRI and (ii) frequency and location by vascular distribution (location of stroke by major vascular territories) in a population based sample. From Mayo Clinic Study of Aging, 347 participants (≥50 years) with infarcts detected on their first MRI were included. Infarct information was identified visually on a FLAIR MRI image and a vascular territory atlas was registered to the FLAIR image data in order to identify the arterial territory of infarction. We identified the subset with a clinical history of stroke based on medical chart review and used a logistic regression to evaluate the risk factors associated with greater probability of a symptomatic stroke vs. SBI. We found that 14% of all individuals with infarctions had a history of symptomatic stroke (Silent: n = 300, symptomatic: n = 47). Factors associated with a symptomatic vs. SBI were size which had an odds ratio of 3.07 (p < 0.001), greater frequency of hypertension (odds ratio of 4.12, p = 0.025) and alcohol history (odds ratio of 4.58, p = 0.012). The frequency of infarcts was greater in right hemisphere compared to the left for SBI. This was primarily driven by middle cerebral artery (MCA) infarcts (right = 60%, left = 40%, p = 0.005). While left hemisphere strokes are more common for symptomatic carotid disease and in clinical trials, right hemispheric infarcts may be more frequent in the SBI group.

Pathophysiology and Treatment of Stroke: Present Status and Future Perspectives

Stroke is the second leading cause of death and a major contributor to disability worldwide. The prevalence of stroke is highest in developing countries, with ischemic stroke being the most common type. Considerable progress has been made in our understanding of the pathophysiology of stroke and the underlying mechanisms leading to ischemic insult. Stroke therapy primarily focuses on restoring blood flow to the brain and treating stroke-induced neurological damage. Lack of success in recent clinical trials has led to significant refinement of animal models, focus-driven study design and use of new technologies in stroke research. Simultaneously, despite progress in stroke management, post-stroke care exerts a substantial impact on families, the healthcare system and the economy. Improvements in pre-clinical and clinical care are likely to underpin successful stroke treatment, recovery, rehabilitation and prevention. In this review, we focus on the pathophysiology of stroke, major advances in the identification of therapeutic targets and recent trends in stroke research.

Precision Medicine and Cardiovascular Health: Insights from Mendelian Randomization Analyses

Cardiovascular disease (CVD) is considered a primary driver of global mortality and is estimated to be responsible for approximately 17.9 million deaths annually. Consequently, a substantial body of research related to CVD has developed, with an emphasis on identifying strategies for the prevention and effective treatment of CVD. In this review, we critically examine the existing CVD literature, and specifically highlight the contribution of Mendelian randomization analyses in CVD research. Throughout this review, we assess the extent to which research findings agree across a range of studies of differing design within a triangulation framework. If differing study designs are subject to non-overlapping sources of bias, consistent findings limit the extent to which results are merely an artefact of study design. Consequently, broad agreement across differing studies can be viewed as providing more robust causal evidence in contrast to limiting the scope of the review to a single specific study design. Utilising the triangulation approach, we highlight emerging patterns in research findings, and explore the potential of identified risk factors as targets for precision medicine and novel interventions.

A prospective study of the hypertriglyceridemic waist phenotype and risk of incident ischemic stroke in a Chinese rural population

OBJECTIVES

The hypertriglyceridemic waist phenotype has been reported as a practical tool to screen people with an increased risk of coronary artery disease and type 2 diabetes. The aim of this study was to investigate the relationship between the phenotype and ischemic stroke in a rural population in south China.

MATERIALS AND METHODS

A total of 4081 participants aged over 35 years old without a stroke history were surveyed in 2009 and followed up from May 2014 to January 2016. The hypertriglyceridemic waist phenotype was defined as a waist circumference ≥90 cm and a triglyceride level ≥2.0 mmol/L in males, and a waist circumference ≥85 cm and a triglyceride level ≥1.5 mmol/L in females. A Cox regression model was used to estimate the association of the phenotype and ischemic stroke.

RESULTS

After a mean of 5.16 years of follow-up, 138 individuals developed ischemic stroke. The hypertriglyceridemic waist phenotype was significantly associated with an increased risk of ischemic stroke before and after adjustment for confounding factors; the hazard ratios and 95% confidence intervals were 1.94 (1.27-2.96) and 1.71 (1.05-2.78), respectively. Further stratified analysis confirmed the associations in females (2.37 [1.09-5.14]) and smokers (3.20 [1.30-7.92]). A significant association of the phenotype and ischemic stroke risk was observed in subjects with normal glucose levels (2.94 [1.58-5.47]) but not in subjects with impaired fasting glucose and diabetes.

CONCLUSIONS

The hypertriglyceridemic waist phenotype is associated with an increased risk of ischemic stroke and might be a simple tool to screen individuals with a high risk for ischemic stroke.

Smoking and drinking influence the advancing of ischemic stroke disease by targeting PTGS2 and TNFAIP3

In the present study, we explored the influence of cigarette smoking and alcohol drinking on gene expression level and related functions and pathways on the development of ischemic stroke (IS) disease. The gene expression profile of E-GEOD-22255 was obtained from 20 IS samples (7 patients without smoking or drinking history and 13 patients with smoking or drinking history) and 20 controls (9 normal controls without smoking or drinking history and 11 controls with smoking or drinking history). The correlation degree between gene expression and grouping were measured by significance analysis of microarray (SAM). Smoking or drinking-related DEGs were screened. GO functional and KEGG pathway enrichment analyses were processed. Based on the KEGG database, a pathway relationship network was constructed. DEGs in significant functions and pathways were inserted and regarded as key DEGs. Gene co-expression network was constructed based on the expression value of key genes. In total, 319 IS-related DEGs, which were induced by smoking and drinking, were screened and enriched in various functions and pathways, including inflammatory response, nuclear factor-κB (NF-κB) signaling pathway and influenza A. Pathway relationship network was constructed with 44 nodes and the hub node was the MAPK signaling pathway. After merging, 87 key DEGs were obtained. The gene co-expression network with 43 node edges was constructed and the hub node was prostaglandin-endoperoxide synthase 2. In IS patients, smoking and drinking may induce different expression of many genes, including PTGS2, TNFAIP3, ZFP36 and NFKBIZ. In addition, these genes participated in various pathways, such as inflammatory response.

Alcohol and cardiovascular disease

Big data puts the link between moderate drinking and lower risk under the microscope

An investigation into the effect of alcohol consumption on health status and health care utilization in Ireland

This paper presents a study of the effect of alcohol consumption on individual health status and health care utilization in Ireland using the 2007 Slán National Health and Lifestyle Survey, while accounting for the endogenous relationship between alcohol and health. Drinkers are categorized as those who never drank, non-drinkers, moderate drinkers, or heavy drinkers, based on national recommended weekly drinking levels in Ireland. The drinking-status equation is estimated using an ordered probit model. Predicted values for the inverse mills ratio are generated, which are then included in the health and health-care utilization equations. Differences in health status for each category of drinker are examined, and the relationship between both alcohol consumption and health with a host of other personal and socio-economic variables is also identified. Given that the measure of health status available is self-assessed, the effect of alcohol consumption on health-care utilization is also analyzed as an alternative measure of health. Findings show that in Ireland, moderate drinkers enjoy the best health status. More moderate drinkers report having very good or excellent health compared with heavy drinkers, non-drinkers, or those who never drank. While heavy drinkers do not report having as good a health status as moderate drinkers, they are better off in terms of health when compared with non-drinkers and those who are lifetime abstainers.

Stroke Risk Factors, Genetics, and Prevention

Stroke is a heterogeneous syndrome, and determining risk factors and treatment depends on the specific pathogenesis of stroke. Risk factors for stroke can be categorized as modifiable and nonmodifiable. Age, sex, and race/ethnicity are nonmodifiable risk factors for both ischemic and hemorrhagic stroke, while hypertension, smoking, diet, and physical inactivity are among some of the more commonly reported modifiable risk factors. More recently described risk factors and triggers of stroke include inflammatory disorders, infection, pollution, and cardiac atrial disorders independent of atrial fibrillation. Single-gene disorders may cause rare, hereditary disorders for which stroke is a primary manifestation. Recent research also suggests that common and rare genetic polymorphisms can influence risk of more common causes of stroke, due to both other risk factors and specific stroke mechanisms, such as atrial fibrillation. Genetic factors, particularly those with environmental interactions, may be more modifiable than previously recognized. Stroke prevention has generally focused on modifiable risk factors. Lifestyle and behavioral modification, such as dietary changes or smoking cessation, not only reduces stroke risk, but also reduces the risk of other cardiovascular diseases. Other prevention strategies include identifying and treating medical conditions, such as hypertension and diabetes, that increase stroke risk. Recent research into risk factors and genetics of stroke has not only identified those at risk for stroke but also identified ways to target at-risk populations for stroke prevention.

Differing association of alcohol consumption with different stroke types: a systematic review and meta-analysis

BACKGROUND

Whether light-to-moderate alcohol consumption is protective against stroke, and whether any association differs by stroke type, is controversial. We conducted a meta-analysis to summarize the evidence from prospective studies on alcohol drinking and stroke types.

METHODS

Studies were identified by searching PubMed to September 1, 2016, and reference lists of retrieved articles. Additional data from 73,587 Swedish adults in two prospective studies were included. Study-specific results were combined in a random-effects model.

RESULTS

The meta-analysis included 27 prospective studies with data on ischemic stroke (25 studies), intracerebral hemorrhage (11 studies), and/or subarachnoid hemorrhage (11 studies). Light and moderate alcohol consumption was associated with a lower risk of ischemic stroke, whereas high and heavy drinking was associated with an increased risk; the overall RRs were 0.90 (95 % CI, 0.85-0.95) for less than 1 drink/day, 0.92 (95 % CI, 0.87-0.97) for 1-2 drinks/day, 1.08 (95 % CI, 1.01-1.15) for more than 2-4 drinks/day, and 1.14 (95 % CI, 1.02-1.28) for more than 4 drinks/day. Light and moderate alcohol drinking was not associated with any hemorrhagic stroke subtype. High alcohol consumption (>2-4 drinks/day) was associated with a non-significant increased risk of both hemorrhagic stroke subtypes, and the relative risk for heavy drinking (>4 drinks/day) were 1.67 (95 % CI, 1.25-2.23) for intracerebral hemorrhage and 1.82 (95 % CI, 1.18-2.82) for subarachnoid hemorrhage.

CONCLUSION

Light and moderate alcohol consumption was inversely associated only with ischemic stroke, whereas heavy drinking was associated with increased risk of all stroke types with a stronger association for hemorrhagic strokes.

Alcohol and stroke: the splitters win again

Study of the relationships of alcohol drinking and risk of stroke can readily become mired in the labyrinthine interactions of drinking categorizations, non-linear associations, disparate cardiovascular conditions, and the heterogeneous types of stroke. This Commentary discusses the recent article by Larsson et al. (BMC Medicine 14:178, 2016). The authors split their material into separate meta-analyses of subarachnoid hemorrhage, intracerebral hemorrhage, and ischemic stroke, finding disparate alcohol-stroke relationships. Our Commentary pursues the disparity theme, using the lumpers versus splitters paradigm to explore several aspects of this complex area.Please see related article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0721-4 .

The effect of alcohol consumption on household income in Ireland

This paper presents a study of the effects of alcohol consumption on household income in Ireland using the Slán National Health and Lifestyle Survey 2007 dataset, accounting for endogeneity and selection bias. Drinkers are categorised into one of four categories based on the recommended weekly drinking levels by the Irish Health Promotion Unit; those who never drank, non-drinkers, moderate and heavy drinkers. A multinomial logit OLS Two Step Estimate is used to explain individual's choice of drinking status and to correct for selection bias which would result in the selection into a particular category of drinking being endogenous. Endogeneity which may arise through the simultaneity of drinking status and income either due to the reverse causation between the two variables, income affecting alcohol consumption or alcohol consumption affecting income, or due to unobserved heterogeneity, is addressed. This paper finds that the household income of drinkers is higher than that of non-drinkers and of those who never drank. There is very little difference between the household income of moderate and heavy drinkers, with heavy drinkers earning slightly more. Weekly household income for those who never drank is €454.20, non-drinkers is €506.26, compared with €683.36 per week for moderate drinkers and €694.18 for heavy drinkers.

Alcohol, wine and mental health: focus on dementia and stroke

The relative risks of coronary heart disease (CHD) and overall mortality are reduced by moderate consumption of alcoholic beverages, particularly wine, which has major implications for public health. It appears likely that this beneficial effect of alcohol will soon be extended to some mental disorders. Although data on psychosis and mood and anxiety disorders are currently lacking, it appears that the relative risks of developing ischaemic stroke and Alzheimer's or vascular dementia are also lowered by moderate alcohol consumption. Such findings are still tentative because of the inherent methodological problems involved in Population-based epidemiological studies, and it is unclear whether the benefit can be ascribed to alcohol itself or to other constituents specific to wine such as polyphenols. Plausible biological mechanisms have been advanced for the protective effect of alcohol and wine against CHD, many of which will also play roles in their protective actions against cerebrovascular disease and dementia. The specific antioxidant properties of wine polyphenols may be particularly important in preventing Alzheimer's disease. Because of the substantially unpredictable risk of progression to problem drinking and alcohol abuse, the most sensible advice to the general public is that heavy drinkers should drink less or not at all, that abstainers should not be indiscriminately encouraged to begin drinking for health reasons, and that light to moderate drinkers need not change their drinking habits for health reasons, except in exceptional circumstances.

Alcohol and cardiovascular diseases: where do we stand today?

For centuries, multiple medical risks of heavy alcohol drinking have been evident with simultaneous awareness of a less harmful or sensible drinking limit. The increased risks of heavy drinking, defined as three or more standard-sized drinks per day, are both cardiovascular (CV) and non-CV. The CV risks include the following: (i) alcoholic cardiomyopathy (ACM), (ii) systemic hypertension, (iii) atrial arrhythmias, (iv) haemorrhagic stroke and, probably, ischaemic stroke. By contrast, modern epidemiological studies have shown lower morbidity and mortality amongst light-moderate drinkers, due mostly to a reduced risk of coronary artery disease (CAD), with contributions from ischaemic stroke and heart failure (HF). A low level of alcohol drinking has no clear relation to increased risk of any CV condition, except for haemorrhagic stroke. There is good evidence that supports the existence of mechanisms by which alcohol might protect against CAD, but the mechanisms for other alcohol-CV associations remain unclear. Interrelationships amongst the CV conditions affect the individual alcohol-disease relationships; for example, lower CAD risk in light-moderate drinkers is to a large extent responsible for the reduced HF risk. International comparison data plus the presence of proposed beneficial nonalcohol components in wine (particularly in red wine) suggest that this beverage type might afford extra CAD protection. However, the effect of beverage choice is confounded by a healthier drinking pattern and more favourable risk traits in wine drinkers. Debate persists about methodological and public health issues related to the epidemiology of alcohol-related CV disease.

Guidelines for the primary prevention of stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.

Alcohol and cardiovascular health: the dose makes the poison…or the remedy

Habitual light to moderate alcohol intake (up to 1 drink per day for women and 1 or 2 drinks per day for men) is associated with decreased risks for total mortality, coronary artery disease, diabetes mellitus, congestive heart failure, and stroke. However, higher levels of alcohol consumption are associated with increased cardiovascular risk. Indeed, behind only smoking and obesity, excessive alcohol consumption is the third leading cause of premature death in the United States. Heavy alcohol use (1) is one of the most common causes of reversible hypertension, (2) accounts for about one-third of all cases of nonischemic dilated cardiomyopathy, (3) is a frequent cause of atrial fibrillation, and (4) markedly increases risks of stroke-both ischemic and hemorrhagic. The risk-to-benefit ratio of drinking appears higher in younger individuals, who also have higher rates of excessive or binge drinking and more frequently have adverse consequences of acute intoxication (for example, accidents, violence, and social strife). In fact, among males aged 15 to 59 years, alcohol abuse is the leading risk factor for premature death. Of the various drinking patterns, daily low- to moderate-dose alcohol intake, ideally red wine before or during the evening meal, is associated with the strongest reduction in adverse cardiovascular outcomes. Health care professionals should not recommend alcohol to nondrinkers because of the paucity of randomized outcome data and the potential for problem drinking even among individuals at apparently low risk. The findings in this review were based on a literature search of PubMed for the 15-year period 1997 through 2012 using the search terms alcohol, ethanol, cardiovascular disease, coronary artery disease, heart failure, hypertension, stroke, and mortality. Studies were considered if they were deemed to be of high quality, objective, and methodologically sound.

Epidemiology of hospitalization due to alcohol-related harm: evidence from a Scottish cohort study

OBJECTIVE

To examine a broad range of risk factors and their association with alcohol-related hospital admissions in a Scottish general population.

DESIGN

Observational record-linkage study in Scotland from 1998 to 2008 involving 8305 respondents aged 16-74 years who participated in the 1998 Scottish Health Survey. Outcome was defined as first-time hospital admission with at least one alcohol-related diagnosis.

METHODS

Cox proportional hazards modelling was applied to estimate the hazard ratio (HR) of first-time hospitalization with an alcohol-related condition associated with a range of behavioural, social and biological risk factors.

FINDINGS

In total, 287 (3.4%) respondents experienced at least one alcohol-related hospitalization during the observation period. Moderate to excessive drinking was the strongest predictor of subsequent admission to hospital with an alcohol-related diagnosis, with clear evidence of a dose - response relationship. Moderate and heavy smoking were also significant predictors of subsequent admission to hospital with an alcohol-related problem. Social factors - such as being in receipt of income-related benefits [HR 1.68, 95% confidence interval (CI) 1.25-2.28]; being retired or economically inactive; and being separated, divorced or widowed (HR 2.34, 95% CI 1.70-3.22) - were also significant predictors of alcohol-related hospitalization.

CONCLUSIONS

Moderate and higher levels of weekly alcohol consumption, moderate to heavy smoking, economic circumstances and marital status are the main risk factors for alcohol-related hospitalization in the Scottish population. These findings add to the evidence that population-based strategies are needed to limit alcohol-related morbidity.

Guidelines for the primary prevention of stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

This guideline provides an overview of the evidence on established and emerging risk factors for stroke to provide evidence-based recommendations for the reduction of risk of a first stroke.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council Scientific Statement Oversight Committee and the AHA Manuscript Oversight Committee. The writing group used systematic literature reviews (covering the time since the last review was published in 2006 up to April 2009), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations using standard AHA criteria (Tables 1 and 2). All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. The guideline underwent extensive peer review by the Stroke Council leadership and the AHA scientific statements oversight committees before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

Schemes for assessing a person's risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic predisposition. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, excessive alcohol consumption, drug abuse, use of oral contraceptives, sleep-disordered breathing, migraine, hyperhomocysteinemia, elevated lipoprotein(a), hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

CONCLUSIONS

Extensive evidence identifies a variety of specific factors that increase the risk of a first stroke and that provide strategies for reducing that risk.

Guidelines for the prevention of stroke in patients with stroke or transient ischemic attack: a guideline for healthcare professionals from the american heart association/american stroke association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches to the implementation of guidelines and their use in high-risk populations.

Alcohol consumption and the risk of morbidity and mortality for different stroke types--a systematic review and meta-analysis

BACKGROUND

Observational studies have suggested a complex relationship between alcohol consumption and stroke, dependent on sex, type of stroke and outcome (morbidity vs. mortality). We undertook a systematic review and a meta-analysis of studies assessing the association between levels of average alcohol consumption and relative risks of ischemic and hemorrhagic strokes separately by sex and outcome. This meta-analysis is the first to explicitly separate morbidity and mortality of alcohol-attributable stroke and thus has implications for public health and prevention.

METHODS

Using Medical Subject Headings (alcohol drinking, ethanol, cerebrovascular accident, cerebrovascular disorders, and intracranial embolism and thrombosis and the key word stroke), a literature search of MEDLINE, EMBASE, CINAHL, CABS, WHOlist, SIGLE, ETOH, and Web of Science databases between 1980 to June 2009 was performed followed by manual searches of bibliographies of key retrieved articles. From twenty-six observational studies (cohort or case-control) with ischemic or hemorrhagic strokes the relative risk or odds ratios or hazard ratios of stroke associated with alcohol consumption were reported; alcohol consumption was quantified; and life time abstention (manually estimated where data for current abstainers were given) was used as the reference group. Two reviewers independently extracted the information on study design, participant characteristics, level of alcohol consumption, stroke outcome, control for potential confounding factors, risk estimates and key criteria of study quality using a standardized protocol.

RESULTS

The dose-response relationship for hemorrhagic stroke had monotonically increasing risk for increasing consumption, whereas ischemic stroke showed a curvilinear relationship, with a protective effect of alcohol for low to moderate consumption, and increased risk for higher exposure. For more than 3 drinks on average/day, in general women had higher risks than men, and the risks for mortality were higher compared to the risks for morbidity.

CONCLUSIONS

These results indicate that heavy alcohol consumption increases the relative risk of any stroke while light or moderate alcohol consumption may be protective against ischemic stroke. Preventive measures that should be initiated are discussed.

Alcohol consumption and cardiovascular mortality among U.S. adults, 1987 to 2002

OBJECTIVES

The aim of this study was to determine the association of alcohol consumption and cardiovascular mortality in the U.S. population.

BACKGROUND

Alcohol consumption has been associated with a lower risk of cardiovascular disease in cohort studies, but this association has not been prospectively examined in large, detailed, representative samples of the U.S. population.

METHODS

We analyzed 9 iterations of the National Health Interview Survey, an annual survey of a nationally representative sample of U.S. adults between 1987 and 2000. Exposures of interest included usual volume, frequency, and quantity of alcohol consumption and binge drinking. Mortality was ascertained through linkage to the National Death Index through 2002. Relative risks were derived from random-effects meta-analyses of weighted, multivariable-adjusted hazard ratios for cardiovascular mortality from individual survey administrations.

RESULTS

Light and moderate volumes of alcohol consumption were inversely associated with cardiovascular mortality. Compared with lifetime abstainers, summary relative risks were 0.95 (95% confidence interval [CI]: 0.88 to 1.02) among lifetime infrequent drinkers, 1.02 (95% CI: 0.94 to 1.11) among former drinkers, 0.69 (95% CI: 0.59 to 0.82) among light drinkers, 0.62 (95% CI: 0.50 to 0.77) among moderate drinkers, and 0.95 (95% CI: 0.82 to 1.10) among heavy drinkers. The magnitude of lower risk was similar in subgroups of sex, age, or baseline health status. There was no simple relation of drinking pattern with risk, but risk was consistently higher among those who consumed >or=3 compared with 2 drinks/drinking day.

CONCLUSIONS

In 9 nationally representative samples of U.S. adults, light and moderate alcohol consumption were inversely associated with CVD mortality, even when compared with lifetime abstainers, but consumption above recommended limits was not.

Alcohol and cardiovascular health

The substantial medical risks of heavy alcohol drinking as well as the probable existence of a less harmful or safe drinking limit have been evident for centuries. Modern epidemiology studies suggest lowered risk of morbidity and mortality among lighter drinkers. Thus, defining "heavy" drinking as > or =3 standard drinks per day, the alcohol-mortality relationship is a J-curve with risk highest for heavy drinkers, lowest for light drinkers and intermediate for abstainers. A number of non-cardiovascular and cardiovascular problems contribute to the increased mortality risk of heavier drinkers. The lower risk of light drinkers is due mostly to lower risk of the most common cardiovascular condition, coronary heart disease (CHD). These disparate relationships of alcoholic drinking to various cardiovascular and non-cardiovascular conditions constitute a modern concept of alcohol and health. Increased cardiovascular risks of heavy drinking include: (1) alcoholic cardiomyopathy, (2) systemic hypertension (high blood pressure), (3) heart rhythm disturbances, and (4) hemorrhagic stroke. Lighter drinking is not clearly related to increased risk of any cardiovascular condition and, in observational studies, is related to lower risk of CHD, ischemic stroke, and diabetes mellitus. A protective hypothesis for CHD is supported by evidence for plausible biological mechanisms attributable to ethyl alcohol. International comparisons and some prospective study data suggest that wine is more protective against CHD than liquor or beer. Possible non-alcohol beneficial components in wine (especially red) support possible extra protection by wine, but a healthier pattern of drinking or more favorable risk traits in wine drinkers may be involved.

Alcohol intake and noncoronary cardiovascular diseases

Moderate drinking has complex associations with cardiovascular diseases other than coronary heart disease. Recent cohort studies examining the relationship between alcohol use and ischemic stroke have shown a modest association, with risk ratios approximating 0.8 and the lowest risk among those who drink less than daily. In contrast, alcohol use is generally associated with an approximate dose-dependent risk for hemorrhagic stroke throughout the full range of intake. Several prospective studies of alcohol intake and congestive heart failure have found lower risk with moderate drinking. This risk is also dose dependent through the moderate range, but its underlying mechanism remains uncertain. Accounting for the lower risk of myocardial infarction associated with moderate intake does not eliminate the observed association. Cohort studies have found no association of long-term alcohol intake with risk of atrial fibrillation below levels of at least 3 standard drinks per day. Finally, two prospective studies have found lower risks of claudication or clinically more severe peripheral arterial disease among moderate drinkers, an association also supported by cross-sectional studies of alcohol intake and ankle-brachial index.

Alcohol Consumption and Abnormalities of Brain Structure and Vasculature

Research on how alcohol consumption influences the structure and blood supply of the brain has generally focused on two primary areas of interest: the atrophic effect of heavy drinking on brain structure and the effects of moderate and heavy drinking on the risk of stroke. Heavy alcohol consumption results in atrophy of gray and white matter, particularly in the frontal lobes, cerebellum, and limbic structures. Heavy drinking also raises the risk of ischemic and hemorrhagic stroke, while light drinking is associated with a lower risk of ischemic stroke. Recently, the author and his colleagues studied alcohol consumption and prevalence of subclinical abnormalities detected by magnetic resonance imaging of the brain among 3376 older adults enrolled in the Cardiovascular Health Study. They found that alcohol consumption was positively associated with measures of brain atrophy and inversely associated with subclinical infarcts in a dose-dependent manner. Alcohol consumption and white matter lesions had a U-shaped relationship, with the lowest prevalence among those who consumed 1-6 drinks per week. Further research is needed to determine how these associations interact to influence overall brain function.

Alcohol-related seizures

Alcohol-related seizures are defined as adult-onset seizures that occur in the setting of chronic alcohol dependence. Alcohol withdrawal is the cause of seizures in a subgroup of these patients; however, concurrent risk factors including pre-existing epilepsy, structural brain lesions, and the use of illicit drugs contribute to the development of seizures in many patients. New onset or a new pattern of alcohol-related seizures, e.g., focal seizures or status epilepticus, should prompt a thorough diagnostic evaluation. This is not indicated if patients have previously completed a comprehensive evaluation and the pattern of current seizures is consistent with past events. Treatment is initially directed at aggressively terminating current seizure activity. This should be followed by prevention of recurrent alcohol-related seizures and progression to status epilepticus during the ensuing 6-h high-risk period. Our purpose is to present recommendations for the diagnostic evaluation, treatment and disposition of these patients based on the current literature.

Sequelae of systemic hypertension in alcohol abstainers, light drinkers, and heavy drinkers

A link exists between alcohol intake and increased blood pressure (BP), with many studies showing increased hypertension prevalence in heavy drinkers. The harmful and beneficial effects of alcohol can confound the study of the long-term risks of alcohol-related hypertension. We therefore studied cardiovascular sequelae separately in heavy drinkers, light drinkers, and abstainers among 127,212 subjects with BP and alcohol intake ascertained at 1978 to 1985 health examinations. Subsequent cardiovascular end points included mortality risk, hospitalization risk, and outpatient diagnosis of hypertension. Analyses were performed for all subjects and stratified by 5 alcohol-drinking categories (from never drinkers to >or=3 drinks/day). With <120/80 mm Hg as the referent, Cox proportional hazards models were used to estimate relative risks and 95% confidence intervals for 3 higher BP categories (120 to 129/80 to 84, 130 to 139/85 to 89, and >or=140/90 mm Hg). The covariates were age, gender, race, body mass index, education, and smoking. The risk of all outcomes was progressively higher for increasing BP categories, with a similarly increased risk for abstainers, light drinkers, and heavy drinkers. The interaction tests for alcohol and BP were not statistically significant for the mortality and hospitalization outcomes. Interpretation was limited by an inability to separate subjects with increased BP from alcohol consumption from those with other etiologies. In conclusion, the data indicate that the risks of hypertension are similar regardless of the amount of alcohol consumption.

Primary Prevention of Ischemic Stroke

Background and Purpose— This guideline provides an overview of the evidence on various established and potential stroke risk factors and provides recommendations for the reduction of stroke risk.

Methods— Writing group members were nominated by the committee chair on the basis of each writer’s previous work in relevant topic areas and were approved by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee. The writers used systematic literature reviews (covering the time period since the last review published in 2001 up to January 2005), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations based on standard American Heart Association criteria. All members of the writing group had numerous opportunities to comment in writing on the recommendations and approved the final version of this document. The guideline underwent extensive peer review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

Results— Schemes for assessing a person’s risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to their potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic factors. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, alcohol abuse, drug abuse, oral contraceptive use, sleep-disordered breathing, migraine headache, hyperhomocysteinemia, elevated lipoprotein(a), elevated lipoprotein-associated phospholipase, hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

Conclusion— Extensive evidence is available identifying a variety of specific factors that increase the risk of a first stroke and providing strategies for reducing that risk.

Guidelines for Prevention of Stroke in Patients With Ischemic Stroke or Transient Ischemic Attack

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches for the implementation of guidelines and their use in high-risk populations.

Alcohol Use and Risk of Ischemic Stroke Among Older Adults

Background and Purpose— The association of light to moderate alcohol consumption with risk of ischemic stroke remains uncertain, as are the roles of potentially mediating factors and modification by apolipoprotein E (apoE) genotype.

Methods— We studied the prospective association of alcohol consumption and risk of ischemic stroke among 4410 participants free of cardiovascular disease at baseline in the Cardiovascular Health Study, a population-based cohort study of older adults from 4 US communities. Participants reported their consumption of alcoholic beverages yearly.

Results— During an average follow-up period of 9.2 years, 434 cases of incident ischemic stroke occurred. Compared with long-term abstainers, the multivariate relative risks of ischemic stroke were 0.85 (95% CI, 0.63 to 1.13), 0.75 (95% CI, 0.53 to 1.06), 0.82 (95% CI, 0.51 to 1.30), and 1.03 (95% CI, 0.68 to 1.57) among consumers of <1, 1 to 6, 7 to 13, and ≥14 drinks per week ( P quadratic trend 0.06). ApoE genotype appeared to modify the alcohol–ischemic stroke relationship ( P interaction 0.08), with generally lower risks among drinkers than abstainers in apoE4-negative participants but higher risks among drinkers than abstainers among apoE4-positive participants. We could not identify candidate mediators among lipid, inflammatory, and prothrombotic factors.

Conclusions— In this study of older adults, the association of alcohol use and risk of ischemic stroke was U-shaped, with modestly lower risk among consumers of 1 to 6 drinks per week. However, apoE genotype may modify this association, and even moderate alcohol intake may be associated with an increased risk of ischemic stroke among apoE4-positive older adults.

Alcohol, wine and mental health: focus on dementia and stroke

The relative risks of coronary heart disease (CHD) and overall mortality are reduced by moderate consumption of alcoholic beverages, particularly wine, which has major implications for public health. It appears likely that this beneficial effect of alcohol will soon be extended to some mental disorders. Although data on psychosis and mood and anxiety disorders are currently lacking, it appears that the relative risks of developing ischaemic stroke and Alzheimer's or vascular dementia are also lowered by moderate alcohol consumption. Such findings are still tentative because of the inherent methodological problems involved in population-based epidemiological studies, and it is unclear whether the benefit can be ascribed to alcohol itself or to other constituents specific to wine such as polyphenols. Plausible biological mechanisms have been advanced for the protective effect of alcohol and wine against CHD, many of which will also play roles in their protective actions against cerebrovascular disease and dementia. The specific antioxidant properties of wine polyphenols may be particularly important in preventing Alzheimer's disease. Because of the substantially unpredictable risk of progression to problem drinking and alcohol abuse, the most sensible advice to the general public is that heavy drinkers should drink less or not at all, that abstainers should not be indiscriminately encouraged to begin drinking for health reasons, and that light to moderate drinkers need not change their drinking habits for health reasons, except in exceptional circumstances.

Cohort Study of Exposure to Environmental Tobacco Smoke and Risk of First Ischemic Stroke and Transient Ischemic Attack

The independent effect of exposure to environmental tobacco smoke (ETS; passive smoking) on the risk of stroke is not well established. We performed a cohort study among 27,698 lifelong nonsmokers with no prior history of stroke, 62% women, aged 30-85 years at enrollment (1979-1985). Self-reported ETS exposure at home and outside home (in hours/week) and stroke risk factors were collected at a health plan in San Francisco and Oakland. Follow-up for hospitalization and death was available through the end of 2000 (median = 16 years). In multivariate analysis adjusting for age, race/ethnicity, educational attainment, marital status, hypertension, diabetes and serum total cholesterol, ETS exposure at home of 20 h or more/week (in relation to <1 h/week) was associated with a 1.29-fold (95% CI 0.75-2.20) and a 1.50-fold (95% CI 1.07-2.09) increased risk of first ischemic stroke among men and women, respectively. No significant associations were found between ETS exposure outside home and ischemic stroke or between exposure to ETS at home or out of home and the risk of transient ischemic attack. Although potentially important confounders (such as dietary habits) were not included in the analysis, high-level ETS exposure at home was independently associated with increased risk of first ischemic stroke among never-smoking women.

Alcohol consumption and risk of stroke: a meta-analysis

CONTEXT

Observational studies suggest that heavy alcohol consumption may increase the risk of stroke while moderate consumption may decrease the risk.

OBJECTIVE

To examine the association between alcohol consumption and relative risk of stroke.

DATA SOURCES

Studies published in English-language journals were retrieved by searching MEDLINE (1966-April 2002) using Medical Subject Headings alcohol drinking, ethanol, cerebrovascular accident, cerebrovascular disorders, and intracranial embolism and thrombosis and the key word stroke; Dissertation Abstracts Online using the keywords stroke and alcohol; and bibliographies of retrieved articles.

STUDY SELECTION

From 122 relevant retrieved reports, 35 observational studies (cohort or case control) in which total stroke, ischemic stroke, or hemorrhagic (intracerebral or total) stroke was an end point; the relative risk or relative odds and their variance (or data to calculate them) of stroke associated with alcohol consumption were reported; alcohol consumption was quantified; and abstainers served as the reference group.

DATA EXTRACTION

Information on study design, participant characteristics, level of alcohol consumption, stroke outcome, control for potential confounding factors, and risk estimates was abstracted independently by 3 investigators using a standardized protocol.

DATA SYNTHESIS

A random-effects model and meta-regression analysis were used to pool data from individual studies. Compared with abstainers, consumption of more than 60 g of alcohol per day was associated with an increased relative risk of total stroke, 1.64 (95% confidence interval [CI], 1.39-1.93); ischemic stroke, 1.69 (95% CI, 1.34-2.15); and hemorrhagic stroke, 2.18 (95% CI, 1.48-3.20), while consumption of less than 12 g/d was associated with a reduced relative risk of total stroke, 0.83 (95%, CI, 0.75-0.91) and ischemic stroke, 0.80 (95% CI, 0.67-0.96), and consumption of 12 to 24 g/d was associated with a reduced relative risk of ischemic stroke, 0.72 (95%, CI, 0.57-0.91). The meta-regression analysis revealed a significant nonlinear relationship between alcohol consumption and total and ischemic stroke and a linear relationship between alcohol consumption and hemorrhagic stroke.

CONCLUSIONS

These results indicate that heavy alcohol consumption increases the relative risk of stroke while light or moderate alcohol consumption may be protective against total and ischemic stroke.