The Moderate Alcohol and Cardiovascular Health Trial (MACH15): Design and methods for a randomized trial of moderate alcohol consumption and cardiometabolic risk

Clinical characteristics of heavy alcohol consumption in young and middle-aged acute cerebral infarction: A 12-month follow-up study

Objective

To investigate the clinical characteristics and prognosis of heavy alcohol consumption among young and middle-aged patients with acute cerebral infarction (ACI).

Methods

A total of 263 young and middle-aged ACI patients were included in the study from June 2018 to December 2020 and classified into heavy drinkers and non-heavy drinkers. Multivariate logistic regression analysis was conducted to assess the association between ACI and heavy alcohol consumption, considering clinical characteristics and one-year post-discharge prognosis.

Results

Among the patients, 78 were heavy drinkers. Heavy drinkers were more likely to consume alcohol 24 h before ACI onset (OR 4.03, 95 % CI 2.26-7.20), especially in the form of liquor (OR 3.83, 95 % CI 1.59-9.20), and had a higher risk of diastolic blood pressure ≥90 mmHg upon admission (OR 2.02, 95 % CI 1.12-3.64). In the one-year post-discharge prognosis, heavy drinkers had a greater likelihood of poor prognosis at 3 months (OR 2.31, 95 % CI 1.01-5.25), were less likely to quit drinking after discharge (OR 0.36, 95 % CI 0.19-0.66), and had a higher risk of recurrent cerebral infarction (OR 2.79, 95 % CI 1.14-6.84).

Conclusions

Over the 12-month follow-up, young and middle-aged ACI patients with heavy alcohol consumption exhibited worse short-term prognosis. Controlling alcohol consumption levels may improve the prognosis of these patients.

A burden of proof study on alcohol consumption and ischemic heart disease

Cohort and case-control data have suggested an association between low to moderate alcohol consumption and decreased risk of ischemic heart disease (IHD), yet results from Mendelian randomization (MR) studies designed to reduce bias have shown either no or a harmful association. Here we conducted an updated systematic review and re-evaluated existing cohort, case-control, and MR data using the burden of proof meta-analytical framework. Cohort and case-control data show low to moderate alcohol consumption is associated with decreased IHD risk - specifically, intake is inversely related to IHD and myocardial infarction morbidity in both sexes and IHD mortality in males - while pooled MR data show no association, confirming that self-reported versus genetically predicted alcohol use data yield conflicting findings about the alcohol-IHD relationship. Our results highlight the need to advance MR methodologies and emulate randomized trials using large observational databases to obtain more definitive answers to this critical public health question.

Is low-level alcohol consumption really health-protective? A critical review of approaches to promote causal inference and recent applications

Heavy and disordered alcohol consumption is a known risk factor for several health conditions and is associated with considerable disease burden. However, at low-to-moderate levels, evidence suggests that drinking is associated with reduced risk for certain health outcomes. Whether these findings represent genuine protective effects or mere methodological artifacts remains unclear, but has substantial consequences for policy and practice. This critical review introduces methodological advances capable of enhancing causal inference from observational research, focusing on the 'G-methods' and Mendelian Randomization. We also present and evaluate recent research applying these methods and compare findings to the existing evidence base. Future directions are proposed for improving our causal understanding of the relationships between alcohol and long-term health outcomes.

Principles of engagement on research and other collaborations between the brewing sector and research entities: the FACT Principles

Public-private partnerships are subject to intense scrutiny. This is specifically the case for sensitive health-related topics such as alcohol consumption. The brewing sector and representatives of the scientific community therefore stressed the need for specific principles for the proper and transparent governance of research and other collaborations between the brewing sector and research entities. At a 1-day seminar, a group of scientists and representatives from the brewing and food sector reached a consensus for such principles. They adhere to the following four fundamental conditions: Freedom of research, Accessibility, Contextualisation and Transparency. The points of focus in the FACT principles are open science, meaning that the methods and results are made accessible and reusable, and relationships are clearly disclosed. Actions to be taken for dissemination and implementation of the FACT Principles are, for instance, publishing them on public websites, including them in formal research agreements, and citing them in scientific publications. Scientific journals and (research) societies are encouraged to support the FACT Principles. In conclusion, the FACT Principles provide a framework for increased transparency and control of funding-related bias in research and other collaborations between the brewing sector and research entities. Monitoring their use and evaluating their impact will help to further refine and enforce the FACT Principles in the future.

Biomarkers of moderate alcohol intake and alcoholic beverages: a systematic literature review

The predominant source of alcohol in the diet is alcoholic beverages, including beer, wine, spirits and liquors, sweet wine, and ciders. Self-reported alcohol intakes are likely to be influenced by measurement error, thus affecting the accuracy and precision of currently established epidemiological associations between alcohol itself, alcoholic beverage consumption, and health or disease. Therefore, a more objective assessment of alcohol intake would be very valuable, which may be established through biomarkers of food intake (BFIs). Several direct and indirect alcohol intake biomarkers have been proposed in forensic and clinical contexts to assess recent or longer-term intakes. Protocols for performing systematic reviews in this field, as well as for assessing the validity of candidate BFIs, have been developed within the Food Biomarker Alliance (FoodBAll) project. The aim of this systematic review is to list and validate biomarkers of ethanol intake per se excluding markers of abuse, but including biomarkers related to common categories of alcoholic beverages. Validation of the proposed candidate biomarker(s) for alcohol itself and for each alcoholic beverage was done according to the published guideline for biomarker reviews. In conclusion, common biomarkers of alcohol intake, e.g., as ethyl glucuronide, ethyl sulfate, fatty acid ethyl esters, and phosphatidyl ethanol, show considerable inter-individual response, especially at low to moderate intakes, and need further development and improved validation, while BFIs for beer and wine are highly promising and may help in more accurate intake assessments for these specific beverages.

1-2 Drinks Per Day Affect Lipoprotein Composition after 3 Weeks-Results from a Cross-Over Pilot Intervention Trial in Healthy Adults Using Nuclear Magnetic Resonance-Measured Lipoproteins and Apolipoproteins

Alcohol consumption ranging from 1−2 drinks/day associates with a lower risk of coronary heart disease in some studies. The underlying mechanisms are unclear. The Metabolic Imprints of Alcoholic Beverages (MetAl) trial aimed to explore the short-term effects of moderate alcohol consumption on cardiovascular biomarkers. A 2 × 3-week cross-over single-blinded intervention trial investigating the effect of 1−2 drinks/day (~12−24 g) compared with abstention on 1H Nuclear Magnetic Resonance-measured main lipoproteins and subfractions was performed in 26 healthy adults. Volunteers were classified as occasional or habitual drinkers based on their habitual alcohol intakes (<2 or ≥2 drinks/week). Compared with abstention, 1−2 drinks/day increased HDL2a-C (p = 0.004), HDL3-C (p = 0.008), and HDL non-significantly (p = 0.19). Total apoA1 and apoA1 in HDL and its subfractions increased (p < 0.05). Novel findings were a decreased apoB/apoA1 ratio (p = 0.02), and increased HDL2a phospholipid content (p = 0.04). In women alone, the results were similar but attenuated, and LDL-P decreased. Thus, changes in apoA1- and HDL-related biomarkers occur within weeks in moderate drinkers. Compared with abstention, 1−2 drinks/day increased total apoA1 more strongly than HDL-C and increased the cholesterol, apoA1, and phospholipid content of several HDL subfractions. Whether this provides a cardiovascular benefit requires further study. Clinicaltrials.gov: NCT03384147.

Alcohol and early mortality (before 65 years) in the 'Seguimiento Universidad de Navarra' (SUN) cohort: does any level reduce mortality?

The aim of this study was to assess the association between alcohol intake and premature mortality (younger than 65 years) and to explore the effect of potential alcohol underreporting by heavy drinkers. We followed-up 20 272 university graduates. Four categories of alcohol intake were considered (abstainer, light, moderate and heavy consumption). Repeated measurements of alcohol intake and updated information on confounders were used in time-dependent Cox models. Potential underreporting of alcohol intake by some heavy drinkers (likely misclassified as light or moderate drinkers) was explicitly addressed in an attempt to correct potential underreporting by using indirect information. During 12·3 years of median follow-up (interquartile range: 6·8-15·0), 226 participants died before their 65th birthday. A higher risk of early mortality was found for the highest category of alcohol intake (≥50 g/d) in comparison with abstention (multivariable-adjusted hazard ratio (HR) = 2·82, 95 % CI 1·38, 5·79). In analyses of alcohol as a continuous variable, the multivariable-adjusted HR was 1·17 (95 % CI 1·08, 1·26), for each 10 g/d of alcohol. This harmful linear association was present both in uncorrected models and in models corrected for potential underreporting. No significant inverse association between light or moderate alcohol intake and premature mortality was observed, even after correcting for potential misclassification. Alcohol intake exhibited a harmful linear dose-response association with premature mortality (<65 years) in this young and highly educated Mediterranean cohort. Our attempts to correct for potential misclassification did not substantially change these results.

Alcohol, Drinking Pattern, and Chronic Disease

This review discusses the inconsistent recommendations on alcohol consumption and its association with chronic disease, highlighting the need for an evidence-based consensus. Alcohol is an addictive substance consumed worldwide, especially in European countries. Recommendations on alcohol consumption are controversial. On one hand, many nonrandomized studies defend that moderate consumption has a beneficial cardiovascular effect or a lower risk of all-cause mortality. On the other hand, alcohol is associated with an increased risk of cancer, neurological diseases, or injuries, among others. For years, efforts have been made to answer the question regarding the safe amount of alcohol intake, but controversies remain. Observational studies advocate moderate alcohol consumption following a Mediterranean pattern (red wine with meals avoiding binge drinking) as the best option for current drinkers. However, agencies such as the IARC recommend abstention from alcohol as it is a potent carcinogen. In this context, more randomized trial with larger sample size and hard clinical endpoints should be conducted to clarify the available evidence and provide clinicians with support for their clinical practice.

Alcohol Consumption and Cardiovascular Disease Risk: Placing New Data in Context

Purpose of Review

A clear link between excessive alcohol consumption and cardiovascular disease (CVD) has been established, but no consensus exists on the effects of moderate alcohol consumption on CVD.

Recent Findings

A lower risk of coronary heart disease and myocardial infarction among moderate drinkers compared to abstainers has been consistently observed in epidemiological studies and meta-analyses of these studies. However, ambiguity remains on the effect of alcohol on other CVDs and all-cause mortality. Short-term randomized controlled trials (RCT) have identified potentially beneficial effects of alcohol consumption on cardiovascular risk factors, but studies investigating genetic polymorphisms that influence alcohol consumption (i.e., Mendelian randomization) have yielded inconclusive results. To date, a long-term RCT providing causal evidence is lacking but urgently needed.

Summary

Triangulation of evidence from different study designs, including long-term RCTs, pragmatic trials and the evaluation of policy measures, combined will lead to the best available evidence.

Alcohol, cardiovascular disease and industry funding: A co-authorship network analysis of systematic reviews

BACKGROUND

Alcohol's effects on heart health is the site of a major scientific controversy. We conducted a co-authorship network analysis of systematic reviews on the impacts on alcohol on cardiovascular disease (CVD) in order to investigate patterns of co-authorship in the literature, with particular attention given to industry funding.

METHODS

We used Epistemonikos to identify systematic reviews. Review characteristics, influential authors, co-authorship subnetworks, prior histories of alcohol industry funding, study outcomes and citations were investigated.

RESULTS

60 systematic reviews with 231 unique authors met our inclusion criteria. 14 systematic reviews were undertaken by authors with histories of alcohol industry funding, including 5 that were funded directly by the alcohol industry itself. All 14 such reviews identified a cardioprotective effect of alcohol. These formed distinct co-authorship subnetworks within the literature. Of reviews by authors with no prior histories of alcohol industry funding, the findings were mixed, with 54% (25/46) concluding there was evidence of health protective effects. These two groups of reviews differed in other respects. Those with industry funding were more likely to study broader outcomes such as 'cardiovascular disease' or 'coronary heart disease' as opposed to specific CVD issues such as hypertension or stroke (93% [13/14] versus 41% [19/46]) (chi-squared 12.4, p < 0.001) and have more included studies (mean of 29 versus 20). They were also more widely cited by others. Over time the proportions of systematic reviews on CVD and alcohol undertaken by authors with no prior histories of alcohol industry funding has increased.

CONCLUSIONS

Systematic reviews undertaken by authors with histories of alcohol industry funding were more likely to study broader outcomes, and be cited more widely, and exclusively reported favorable conclusions.

Alcohol consumption in relation to cardiovascular diseases and mortality: a systematic review of Mendelian randomization studies

The causal effects of alcohol-in-moderation on cardiometabolic health are continuously debated. Mendelian randomization (MR) is an established method to address causal questions in observational studies. We performed a systematic review of the current evidence from MR studies on the association between alcohol consumption and cardiometabolic diseases, all-cause mortality and cardiovascular risk factors. We performed a systematic search of the literature, including search terms on type of design and exposure. We assessed methodological quality based on key elements of the MR design: use of a full instrumental variable analysis and validation of the three key MR assumptions. We additionally looked at exploration of non-linearity. We reported the direction of the studied associations. Our search yielded 24 studies that were eligible for inclusion. A full instrumental variable analysis was performed in 17 studies (71%) and 13 out of 24 studies (54%) validated all three key assumptions. Five studies (21%) assessed potential non-linearity. In general, null associations were reported for genetically predicted alcohol consumption with the primary outcomes cardiovascular disease (67%) and diabetes (75%), while the only study on all-cause mortality reported a detrimental association. Considering the heterogeneity in methodological quality of the included MR studies, it is not yet possible to draw conclusions on the causal role of moderate alcohol consumption on cardiometabolic health. As MR is a rapidly evolving field, we expect that future MR studies, especially with recent developments regarding instrument selection and non-linearity methodology, will further substantiate this discussion.

Alcohol use and cardiometabolic risk in the UK Biobank: A Mendelian randomization study

Observational studies suggest alcohol use promotes the development of some adverse cardiometabolic traits but protects against others including outcomes related to coronary artery disease. We used Mendelian randomization (MR) to explore causal relationships between the degree of alcohol consumption and several cardiometabolic traits in the UK Biobank. Using the well-established ADH1B Arg47His variant (rs1229984) and up to 24 additional SNPs recently found to be associated with alcohol consumption in an independent dataset as instruments, we conducted two-stage least squares and inverse weighted variance MR analyses, both as one-sample analyses in the UK Biobank and as two-sample analyses in external consortia. In the UK Biobank inverse variance weighted analyses, we found that one additional drink of alcohol per day was positively associated with systolic blood pressure (beta = 2.65 mmHg [1.40, 3.89]), hemorrhagic stroke (OR = 2.25 [1.41, 3.60]), and atrial fibrillation (OR = 1.26 [1.07, 1.48]), which were replicated in multivariable analyses. Alcohol was also associated with all cardiovascular disease and all-cause death. A positive association with myocardial infarction did not replicate in multivariable analysis, with suggestive mediation through blood pressure; similarly, a positive association between alcohol use with type 2 diabetes was mitigated by BMI in multivariable analysis. Findings were generally null in replication with two-sample analyses. Alcohol was not protective for any disease outcome with any analysis method, dataset, or strata. Stratifications by sex and smoking in the UK Biobank revealed higher point estimates of risk for several outcomes for men and mixed results for smoking strata, but no statistically significant heterogeneity. Our results are consistent with an overall harmful and/or null effect of alcohol on cardiometabolic health at all levels of use and suggest that even moderate alcohol use should not be promoted as a part of a healthy diet and lifestyle.

Consensus and Controversy in the Debate over the Biphasic Impact of Alcohol Consumption on the Cardiovascular System

In the past few decades, research has focused on the importance of addressing modifiable risk factors as a means of lowering the risk of cardiovascular disease (CVD), which represents the worldwide leading cause of death. For quite a long time, it has been considered that ethanol intake has a biphasic impact on the cardiovascular system, mainly depending on the drinking pattern, amount of consumption, and type of alcoholic beverage. Multiple case-control studies and meta-analyses reported the existence of a "U-type" or "J-shaped" relationship between alcohol and CVD, as well as mortality, indicating that low to moderate alcohol consumption decreases the number of adverse cardiovascular events and deaths compared to abstinence, while excessive alcohol use has unquestionably deleterious effects on the circulatory system. However, beginning in the early 2000s, the cardioprotective effects of low doses of alcohol were abnegated by the results of large epidemiological studies. Therefore, this narrative review aims to reiterate the association of alcohol use with cardiac arrhythmias, dilated cardiomyopathy, arterial hypertension, atherosclerotic vascular disease, and type 2 diabetes mellitus, highlighting literature disagreements over the risk and benefits of low to moderate drinking on the cardiovascular system.

Benefits and hazards of alcohol-the J-shaped curve and public health

Purpose

The purpose of this paper is a review of updated evidence of a J-shaped association between alcohol consumption and the risk of coronary heart disease (CHD) and all-cause mortality in relation to public health issues to create a basis for sensible individual health deliberations.

Design/methodology/approach

A review of the evidence from the first observation of a J-shaped association between a moderate alcohol intake and CHD in 1926 to recent studies of the effect of healthy lifestyles (including moderate alcohol intake) on life expectancy free of cardiovascular disease (CVD), cancer and Type 2 diabetes. An update on the biological plausibility of the J-shaped association with focus on recent findings of the association of alcohol intake and blood lipid levels.

Findings

Plausible J-shaped relations between light to moderate alcohol consumption and the risk of CHD, CVD mortality and all-cause mortality have been found in a large number of robust epidemiological studies. Among the potential mechanisms underlying the proposed protective effects are higher levels of high-density lipoprotein lacking apolipoprotein C3, reduced platelet aggregability, increased level of endothelial cell fibrinolysis, increased insulin sensitivity and decreased inflammation.

Originality/value

The existence of a J-shaped association between alcohol consumption and the risk of CHD and all-cause mortality is based on observational evidence and accordingly challenged by a degree of uncertainty leading some public health circles to state: “there is no safe level of alcohol consumption.” The authors propose that communication on the pros and cons of alcohol intake should emphasize the nadir of a J-shaped curve as a healthy range for the general population while advice regarding the consumption of alcohol should be adjusted to factor in the risks and potential benefits for each individual patient considering age, sex, family history, personal drinking history and specific medical history.