This article was by By Patrice Wendling February 28, 2017
TORONTO, ON and LONDON, UK — Two new studies provide reassuring evidence that drinking two alcoholic beverages per day is not harmful to cardiovascular health.
The first study, a meta-analysis of 36 trials, found that reducing alcohol intake lowered blood pressure in a dose-dependent fashion.
Lowering alcohol consumption had no significant effect on blood pressure for people drinking two alcoholic beverages per day, but was associated with higher subsequent BP reduction for those drinking beyond this level.
People who threw back six or more drinks per day at baseline and cut their intake roughly in half had the strongest reduction in systolic BP (mean difference -5.50 mm Hg; 95% CI -6.70 to -4.30) and diastolic BP (mean difference -3.97 mm Hg; 95% CI -4.70 to -3.25).
“For heavy drinkers, a reduction in alcohol consumption to two or fewer drinks per day could be the first choice in treatment of hypertension,” lead author Dr Michael Roerecke (Centre for Addiction and Mental Health, Toronto, ON) and colleagues write in the study, published online in Lancet Public Health.
The second study took a rare long view of alcohol consumption over a 25-year time span and its association with changes in arterial stiffness as measured by carotid-femoral pulse-wave velocity (PWV).
PWV has been shown to be a reliable prognostic marker for cardiovascular morbidity and mortality, with higher PWV values signaling greater arterial stiffness.
After analyzing data for 3869 mostly male (73%) civil servants in the Whitehall II cohort study, British investigators found that men who regularly drank heavy amounts of alcohol (>3.9 ounces ethanol/wk or about >14 servings/wk) had higher baseline PWV values than stable moderate (<3.9 ounces ethanol/wk) drinkers (b=0.26 m/s; P=0.045).
A similar effect was seen among women who were regular heavy drinkers in models adjusted for demographic and lifestyle factors (b=0.73 m/s; P=0.029) but the association was no longer significant after full adjustment including clinical covariates (b=0.42 m/s; P=0.169)
“Compared with heavier volumes, moderate intake is known to be associated with higher high-density lipoprotein cholesterol, a protective factor against arterial stiffening,” lead author Dr Darragh O’Neill (University College London, UK) and colleagues write in the study, published February 20, 2017 in the Journal of the American Heart Association.
Commenting to heartwire from Medscape, American Society of Hypertension president Dr John Bisognano (University of Rochester Medical Center, NY) said, “It was known from the cholesterol data in the past that it always looked like two drinks a day was the optimal number if your goal was to improve HDL cholesterol, but what this is telling us now is that there’s a threshold that if you go above two drinks a day you start to move things in the wrong direction.”
Bisognano said patients regularly ask whether they should start drinking in order to improve their cholesterol, and while he wouldn’t necessarily recommend someone start just for that reason, alcohol is something that spans almost all cultures and countries.
“What I’m looking at is people who just truly enjoy two glasses of wine or two beers or two mixed drinks a day, and I have reasonable evidence now that they are not doing themselves any harm.”
Asked why the effect of alcohol on arterial stiffness was more pronounced in males than females, Bisognano said it may be due to the small number of female participants, but “it may also be that there’s other cardiovascular risk factors such as hypertension, hyperlipidemia that affect males earlier than females. So it may just be that you are seeing an effect of age.”
Participants in the Whitehall II cohort were originally recruited between 1985 and 1988 (age range 34 to 56 years) and self-reported alcohol consumption through 2009. PWV was measured at baseline and then during follow-up in 2012 and 2013.
Men were more likely to be heavy drinkers (stable 17.l7%, unstable 27.9%) than females, who were more than twice as likely to be stable nondrinkers (8.2%) and former drinkers (18.7%). While few among either sex were current smokers, 68% of males and 74.1% of women failed to meet World Health Organization–recommended weekly exercise levels.
Mean PWV values increased significantly among males from 8.5 m/s at baseline to 9.1 m/s by follow-up and from 8.2 m/s to 8.7 m/s among females (P<0.001 for both).
While all drinker types, regardless of sex, had increases in their PWV from baseline across follow-up, only male former drinkers had significant accelerated progression of arterial stiffness (b=0.11 m/s; P=0.009).
Bisognano said the message for physicians going forward is to ask their patients not whether they consume alcohol, but how much.
“If you have someone who is drinking heavily, they have another issue that has to be addressed in a more formal alcohol-reduction program,” he said.
Roerecke and his meta-analysis colleagues write that “a reduction of both alcohol consumption and blood pressure has the potential for substantial synergistic health gains in terms of morbidity, mortality, and healthcare costs; yet only about half of hypertension guidelines worldwide recommend reduction in alcohol consumption to reduce raised blood pressure.”
By their calculations, if half of UK residents drinking more than two drinks a day reduced their alcohol intake, the proportion of people with systolic blood pressure >140 mm Hg would fall by 4.4% for men and 1.2% for women, with most of the effect emerging in mid-adulthood. This reduction in BP would translate into 7272 inpatient hospitalizations and 678 cardiovascular deaths prevented every year.
The meta-analysis was funded by the National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health (NIH). Roerecke reports grants from these institutes during the study and grants and personal fees from Lundbeck outside the conduct of the study. Disclosures for the coauthors are listed in the paper. The Whitehall II study was supported by funds from the UK Medical Research Council, British Heart Foundation, and the NIH. The authors as well as Bisognano report no relevant financial relationships.
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- Roerecke M, Kaczorowski J, Tobe SW, et al. The effect of a reduction in alcohol consumption on blood pressure: a systematic review and meta-analysis. Lancet Public Health 2017; DOI:10.1016/S2468-2667(17)30003-8. Article
- O’Neill D, Britton A, Brunner EJ, et al. Twenty-five-year alcohol consumption trajectories and their association with arterial aging: a prospective cohort study. J Am Heart Assoc 2017; DOI:10.1161/JAHA.116.005288. Article
original article appears on: http://www.medscape.com/viewarticle/876422