Exploring the effects of reduced alcohol consumption on major adverse cardiovascular and cerebrovascular events in chronic heavy drinkers: a nationwide population-based cohort study
Authors: Kang D O , Lee D I , Kang J , Chu W , Park S Y , Jo E , Kim J , Lee J W , Jung J M 
Published: October 2024

Abstract

Background/Introduction
Chronic heavy alcohol consumption is a well-established risk factor for cardiovascular disease (CVD), and the potential cardiovascular benefits of mild to moderate alcohol consumption need validation, particularly in the context of behavioral change from heavy drinking. Currently, there is a lack of research examining the potential benefits of reduced alcohol consumption in chronic heavy drinkers, specifically in relation to different subtypes of CVD. We hypothesized that habitual changes in alcohol consumption among chronic heavy drinkers would have a long-term prognostic effect on future CVD outcomes.

Purpose
We investigated the association between reduced alcohol consumption and the risk of major adverse cardiovascular and cerebrovascular events (MACCE) in chronic heavy drinkers.

Methods
From the Korean National Health Insurance Service-Health Screening database, we included a cohort of chronic heavy drinkers who underwent serial health examinations over two consecutive time-periods (first period: 2005–2008; second period: 2009–2012). Heavy drinking was defined according to the National Institute on Alcohol Abuse and Alcoholism criteria as &gt;56 g/day or &gt;196 g/week for men, and &gt;42 g/day or &gt;98 g/week for women. Overall, 13,854 heavy drinkers at baseline (mean age 55.84 ± 5.98 years; 91.6 % men) were categorized into two groups based on the alcohol consumption changes in the second period: sustained heavy drinking (n=9,403; 67.9%) or reduced drinking (n=4,451; 32.5%). The primary outcome was MACCE, a composite of nonfatal myocardial infarction or angina undergoing revascularization, any stroke accompanied by hospitalization, and all-cause death during follow-up.

Results
In this nationwide population-based cohort study, during a total follow-up of 107,102 person-years, the sustained heavy drinking group experienced a significantly higher incidence of MACCE than the reduced drinking group (incidence rate, 825 vs. 655 per 100,000 person-years; log-rank p=0.004). Reduced alcohol consumption was associated with a 28% lower risk of MACCE compared to sustained heavy drinking (adjusted-hazard ratio [HR]: 0.780, 95% confidence interval [CI] 0.656–0.928). These benefits were mostly driven by a significant reduction in the incidence of angina (adjusted-HR: 0.631, 95% CI 0.425–0.926) and ischemic stroke (adjusted-HR: 0.657, 95% CI 0.472–0.914). The preventive effects of reduced alcohol intake were consistently observed across various subgroups of heavy drinkers, except for smoking status (p-interaction=0.015) and even after including abstainers in the sensitivity analysis.

Conclusion
Reduced alcohol consumption in heavy drinkers could lower the future risk of CVD, with the most pronounced benefits expected for stable/unstable angina and ischemic stroke. Further research is warranted to explore the optimal strategies for promoting sustained reductions in alcohol intake.Cumulative MACCE incidence curves