In a recent study published in JAMA Network Open, a gaggle of researchers explored the link between lowering alcohol intake and the occurrence of major opposed cardiovascular events (MACEs) in heavy drinkers, specializing in different subtypes of heart problems (CVD).

Study: Reduced Alcohol Consumption and Major Hostile Cardiovascular Events Amongst Individuals With Previously High Alcohol Consumption. Image Credit: Vaclav Mach / Shutterstock

Background 

Alcohol consumption significantly influences each individual and public health, with research showing its complex relationship with CVD. While light to moderate drinking is believed to supply some protection against CVD, this effect varies by the style of CVD, and the connection between alcohol intake and heart health will not be linear. Previous studies have typically measured alcohol consumption at a single cut-off date and compared drinkers to non-drinkers without considering changes in drinking habits over time. Further research is crucial to know the mechanisms underlying the cardiovascular advantages of reduced alcohol consumption and to determine tailored guidelines for various populations and CVD subtypes.

Concerning the study 

In the current study, researchers utilized data from the Korean National Health Insurance Service–Health Screening (NHIS-HEALS) database to look at a representative sample of Korean adults aged 40 to 79. Approved by Chungbuk National University Hospital’s institutional review board (IRB) and adhering to the Declaration of Helsinki and Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines, the study utilized the National Health Screening Program’s (NHSP’s) broad coverage to research information on demographics, medical histories, and lifestyle aspects, including alcohol consumption. This careful documentation provided a foundation for an in depth investigation into the consequences of alcohol on health.

Participant selection was methodical, excluding non-drinkers within the latter period to avoid confounding aspects just like the sick-quitter effect. The study’s rigor prolonged to defining heavy drinking based on established criteria and dividing participants into groups based on their drinking habits over time. 

Confounding variables were identified with precision, including a variety of demographic, health, and lifestyle aspects. The study’s outcomes centered on MACEs, with detailed coding and procedures to make sure accuracy. Statistical analyses were conducted with sophisticated tools and methods, including propensity rating matching (PSM) and multivariate Cox proportional hazards regression models, to attract reliable conclusions in regards to the relationship between alcohol consumption and cardiovascular health.

Study results 

In the great study analyzing 21,011 participants with initially high alcohol consumption levels, 14,220 maintained their heavy drinking habits, while 6,791 reduced their intake to mild or moderate levels. Predominantly male (90.3%) and averaging 56 years of age, this cohort provided an in depth snapshot of baseline health and lifestyle characteristics. Initially, the heavy drinkers were younger on average and had a better proportion of males in comparison with those that reduced their alcohol consumption.

Clinical indicators similar to body mass index (BMI), blood pressure, and various biochemical markers showed differences between the groups, with the sustained heavy drinkers generally presenting poorer health metrics. Interestingly, despite the health disparities, after PSM, these groups were closely aligned on most variables, allowing for a more accurate comparison of outcomes.

Over the course of the study, the incidence of MACEs was notably higher within the group that continued heavy drinking in comparison with those that reduced their intake, with a big divergence in outcomes over time. Specifically, reduced drinking was related to a 23% lower risk of experiencing a MACE. When examining specific CVDs, reductions in alcohol consumption significantly lowered the chance of coronary artery disease (CAD), angina, any stroke, ischemic stroke, and all-cause mortality, while no advantages were observed for nonfatal myocardial infarction (MI) or hemorrhagic stroke.

Subgroup analyses highlighted the cardiovascular benefits of reducing alcohol intake across various demographics and health statuses, including age, gender, BMI, smoking status, and levels of physical activity. Notably, these advantages were evident no matter pre-existing conditions like atrial fibrillation and chronic kidney disease and were consistent across different socioeconomic statuses and comorbidities.

Further sensitivity analyses, which excluded variables potentially modifiable by alcohol consumption changes, reaffirmed the cardiovascular advantages of reducing alcohol intake. 

Conclusions 

To summarize, within the study, heavy drinkers who reduced their alcohol intake demonstrated a significantly lower risk of cardiovascular events over a decade, with notable health improvements visible three years post-reduction. This reduction in alcohol consumption correlated with a broad array of cardiovascular advantages, especially in lowering the chance of ischemic stroke and angina-related interventions. The study clarifies the complex biological mechanisms through which moderate alcohol consumption may confer cardiovascular protection, highlighting improvements in lipid regulation, endothelial function, and reduced inflammation. Importantly, it revealed specific reductions in CAD and ischemic stroke risk amongst heavy drinkers, underlining the potential health advantages of moderating alcohol intake.