A new study suggests that the previously reported benefits of alcohol intake for patients with cardiovascular disease appear to be partially mediated by the modulation of stress-associated brain activity.
The researchers found two J-shaped relationships: one between alcohol intake and major cardiovascular adverse events (MACE) and another between alcohol intake and stress-associated amygdala metabolic activity, as measured by fluor / fluorodeoxyglucose (CT) positron emission tomography (CT)18F-FDG PET / CT).
Compared to those with low alcohol consumption, which is defined as having less than one drink per week, or those with high alcohol consumption, which is defined as having more than 14 drinks per week, those with moderate alcohol consumption (between one and 14 drinks per week) were less likely to have MACE events, and were also found to have less tonsillar activity in the image.
Kenechukwu Mezue, MD, clinical and nuclear cardiology researcher at Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, reported the findings at a press conference and will present the study in an oral session at next American College of Cardiology 2021 Scientific Session.
“Association is not causality” is a mantra we learn in epidemiology, ”Mezue noted theheart.org | Cardiology Medscape in an email. However, these findings present a possible mechanism for part of the cardiovascular benefit of moderate alcohol, which should be examined in a later study.
“Following an analysis that robustly controlled for confounding factors, including socioeconomic and lifestyle factors, there was a 20% reduction in MACE events due to moderate alcohol intake,” he noted. Mezue, according to previous research.
The current study also showed for the first time that moderate alcohol intake was associated with a reduction in brain activity associated with stress, which may explain some of the benefits of cardiovascular outcomes.
“Our study is not intended to encourage alcohol consumption, as excessive alcohol intake is associated with a lot of damage [including liver damage], and even moderate alcohol intake is associated with an increased risk and dependence on cancer, ”Mezue warned.
Rather, “we believe that shedding light on this potential mechanism for reducing cardiovascular events may open doors to new therapies that can optimize stress reduction without the harmful effects of alcohol,” he said. For example, exercise or yoga may also be prescribed to reduce stress.
Future studies with repeated brain scans and more detailed assessments of alcohol intake over time could provide additional insight into the mechanism of action.
Confirm previous studies
“This study confirmed previous studies showing that moderate consumption appears to have a lower risk of cardiovascular events,” said press conference moderator Eugene Yang, MD, of the University of Washington, Seattle, Washington, and chairman of the ACC Prevention of Cardiovascular Disease Council.
“Then he goes further looking at the brain image,” he said theheart.org | Cardiology Medscape in an interview. “It may give a clue as to why there is one [cardiovascular] alcohol will benefit in moderation. “
The limitations of the study, Yang noted, include that it was not allowed to distinguish between men and women, although it is drunk moderately as up to seven drinks a week for women and up to 14 drinks a week. for men.
In addition, the individuals only underwent a scan, but brain activity is dynamic, he said.
In addition, it would have been good to have data on excessive alcohol consumption (defined as taking> 5 drinks for men and> 4 drinks for women in 2 hours), which, in a previous study, was related to a higher risk of cardiovascular events.
He also noted that the researchers did not have information on the type of alcohol consumed, so they could not determine whether, for example, red wine was more beneficial.
Massachusetts General Brigham Biobank
The researchers identified 53,064 individuals in Massachusetts General Brigham Biobank, who agreed to provide data for genetic studies. They all provided self-reported information on alcohol consumption, as indicated in a survey question.
The mean age of the participants was 57 years and 60% were women.
Participants were divided into three groups based on alcohol consumption. About half had low or low alcohol consumption, half had moderate alcohol consumption, and only 2,000 drank> 14 alcoholic beverages a week.
A subset of 752 participants underwent whole body 18PET-TC F-FDG analysis, mainly for cancer diagnosis or surveillance, between 2005 and 2020. They fasted overnight and abstained from alcohol for 12 hours before the scan.
In this subset, 220 individuals had MACE, defined as unstable angina, myocardial infarction, coronary revascularization, symptomatic peripheral artery disease, peripheral revascularizations, stroke, i transient ischemic attack.
After adapting by age, sex, race, hypertension, diabetes, hyperlipemia, smoking, physical activity, body mass index, employment, education, income, depression, anxiety, i insomnia, moderate alcohol intake was associated with a reduced risk of MACE compared with low / zero alcohol intake (probability of 0.80; Pg <.0001).
The researchers determined the proportion of metabolic activity in the amygdala, which increases during stress, to that of the prefrontal cortex, which acts to modulate amygdala activity.
Activity in the prefrontal cortex was similar in all three groups.
“It’s important to note that moderate chronic alcohol intake did not have a general effect on the brain,” Mezue said. “Rather, it preferentially reduced activity in stress-related areas.”
After adjusting for age and sex, compared with low / zero alcohol intake, moderate intake was associated with a decrease in stress-associated neuronal activity (Pg = 0.018).
Researchers do not report relevant financial relationships.
Annual Scientific Session of the American College of Cardiology (ACC) 2021: Summary 912-08. It will be presented on May 17, 2021.
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