Increased acute CV risk 1 hour after moderate and heavy alcohol consumption
Alcohol and Immediate Risk of Cardiovascular Events: A Systematic Review and Dose-Response Meta-AnalysisMostofsky E, Chahal HS, Mukamal KJ, et al. - Circulation 2016; published online ahead of print
Existing evidence suggests that habitual moderate consumption of alcohol is associated with a lower risk of CHD, whereas heavy alcohol consumption may be harmful . A single dose of alcohol causes within 1-3 hours increased heart rate, electromechanical delay and impaired fibrinolysis [2-4]. On the other hand, 12-24 hours later, transient improvements in flow-mediated vasodilatation, endothelial function and coagulation have been reported [5,6]. After weeks of regular intake, there are improvements in inflammatory markers, lipid profile, adipokines and insulin sensitivity .
One to two drinks per day are linked with improvements in HDL-c, heart rate variability, endothelial function, insulin sensitivity, coagulation and fibrinolytic cascades and a lower risk of cardiovascular disease and stroke (both ischemic and hemorrhagic) [7,8]. However, the consumption of 3-4 drinks per day is associated with a higher risk of hypertension, diabetes, cardiovascular disease, stroke, and mortality after MI [8,9]. Accordingly, the 2015 Dietary Guidelines Advisory Committee recommended that, if alcohol is consumed, it should not exceed one drink per day for women and two drinks per day for men .
In this systematic review and dose-response meta-analysis of 23 studies including almost 30.000 participants, the risk of myocardial infarction (MI) and stroke (both ischemic and hemorrhagic, IS and HS) within hours and days after alcohol intake were evaluated, because the immediate risks after alcohol intake have not been described so far.
Moderate alcohol consumption was associated with
- a higher CV risk (approximately twofold) in the hour after alcohol intake
- a lower risk of MI and HS (2-4 drinks associated with 30% lower relative risk) after 24 hours
-a lower risk of IS after one week (6 drinks associated with 19% lower risk)
Heavy alcohol drinking was associated with
- a higher CV risk in the following day (6-9 drinks: RR: 1.3-2.3)
- a higher CV risk in the following week (19-30 drinks: RR: 2.25-6.2)
A U-shaped association was observed between the amount of alcohol intake within the 24 hours prior to MI onset and MI risk (pcurve<0.001) with
- the greatest benefit following approximately 28 grams of alcohol (2 drinks) in one day (RR: 0.67)
- a higher risk following approximately 108 grams (9 drinks) in one day (RR: 1.59).
When considering a week following alcohol consumption, a lower risk of MI was seen with moderate intake, and a higher risk after heavy alcohol consumption.
Similar U-shaped associations were observed for IS risk (pcurve=0.007) and for HS risk (pcurve=0.02).
Immediately following alcohol consumption, both harmful and protective physiologic responses take place. Moderate and heavy alcohol consumption was associated with a higher immediate CV risk in the hour after alcohol intake. After 24 hours, habitual moderate alcohol consumption was associated with a CV benefit, but heavy alcohol consumption was associated with continued CV risk.