Distinctive study design supports association
Studies examining the association of alcohol consumption with cardiovascular (CVD) outcomes have been mostly observational in nature because of ethical considerations, Anna Kucharska-Newton, PhD, of the University of North Carolina at Chapel Hill, said in an interview. “Results of those studies have not been conclusive, and more research is needed. This study takes advantage of the ‘natural experiment’ of the randomized distribution of genetic variants associated with alcohol consumption,” said Dr. Kucharska-Newton, who served as moderator for the session at the meeting when the study was presented. “This method is similar to a randomized clinical trial and as such is less subject to confounding and potential reverse causality than an observational study..
“The findings confirm data from previous studies, including published data based on the UK Biobank study and the FinnGen registry of genetic data,” said Dr. Kucharska-Newton. “Findings from that study are largely supportive, suggesting that alcohol intake is associated with increased risk of coronary artery disease, an association that is sustained following adjustment for smoking.
“What the present study adds is an elegant presentation of the nonlinearity in that association. However, in contrast to the earlier study that included participants who reported drinking 1-2 drinks per week, Mr. Biddinger and colleagues examined effects among those drinking 7-28 drinks per week, making generalization to light to moderate drinkers [the majority] difficult,” she noted.
As for clinical implications, “assessment of habitual drinking is an important element in routine clinical care.” Dr. Kucharska-Newton noted. “Alcohol intake of seven or more drinks per week is associated exponentially with increased risk of coronary artery disease and, as other data suggest, increased levels of CVD risk factors. Therefore, CVD risk factor control is of particular importance in this population.
“Additional research in populations of ancestry other than White European is very much needed,” Dr. Kucharska-Newton emphasized. “Replication of the analyses presented by Mr. Biddinger and colleagues in different cohorts would strengthen inferences from this study. Extension of study findings to clinically manifest CVD would provide more relevant take-home messages. However, prior studies, based on Mendelian randomization protocols, suggest that adjustment for lifestyle factors attenuates the association of alcohol intake with adverse clinical CVD outcomes.”
Mr. Biddinger had no financial conflicts to disclose, but several coauthors disclosed relationships with companies including Novartis, Regeneron, Bayer, Quest Diagnostics, Corvidia, Pfizer, Verve Therapeutics, and Medgenome. Dr. Kucharska-Newton had no financial conflicts to disclose.