The findings were based on blood pressure readings and self-reported alcohol consumption patterns from a randomly selected sample of 2,609 white men and women between the ages of 35 and 80 who took part in the Western New York Health Study. All participants were free of other cardiovascular diseases.
In a computer-assisted, in-person interview, participants provided data on their alcohol consumption during the past 30 days. Questions covered how often they drank during that time period, when they drank (weekdays versus weekends), how much they drank (drinks per day) and if they drank with meals, with snacks or without food. They also reported whether they drank mostly beer, wine or liquor.
Based on responses, participants also were classified as lifetime abstainers, those who reported having fewer than 12 drinks in their lifetime or in any one-year period; non-current drinkers, participants having more than 12 drinks during their lifetime or in any one year but no drinks during the past 30 days, and current drinkers, participants having consumed at least one alcoholic beverage during the past 30 days.
Current drinkers were divided into categories depending on how often they drank: less than weekly, weekly non-daily; weekend only; or weekly daily.
Three blood-pressure readings were taken on each participant by trained personnel during the interview. The mean of the second and third reading then were used for the study. Hypertension was defined by systolic blood pressure of 140 mm Hg or greater or diastolic blood pressure of 90 mm Hg or greater, or by the fact that an individual was taking medication for high blood pressure.
Results confirmed findings of a previous study conducted in Italy by some of the same investigators and also showed for the first time that even light to moderate alcohol intake outside of meals puts drinkers at risk for hypertension.
"This is a novel finding with potentially important clinical implications," said Stranges. "It points out that drinking without food may counteract any benefit to the cardiovascular system associated with moderate alcohol consumption."
Those drinking mostly outside of mealtimes reported a significant increase in risk of hypertension compared with either lifetime abstainers or those drinking mostly with food.
Not surprisingly, results confirmed that a high level of alcohol consumption -- defined as more than two drinks per day -- is associated with an increased risk of high blood pressure. "In fact," said Stranges, "the average volume of alcohol consumed during the past 30 days played a much more important role in the relationship between drinking and high blood pressure than how often a person drank."
There was no difference in risk based on the type of alcohol consumed, or the gender of drinkers.
"These findings add new and important information to the mounting evidence linking drinking pattern to numerous health outcomes" concluded Stranges.
Additional researchers on the study were, Joan Dorn, Ph.D., Jo Freudenheim, Ph.D., Paola Muti, M.D., and Maurizio Trevisan, M.D., from the UB Department of Social and Preventive Medicine; Tiejan Wu, Ph.D., formerly of UB, now at East Tennessee State University, Johnson City, Tenn.; Eduardo Farinaro, M.D., of "Federico II" University of Naples Medical School, Naples, Italy; Marcia Russell, Ph.D., of the Prevention Research Center, Pacific Institute for Research and Evaluation, Berkeley, Calif., and Thomas H. Nochajski, Ph.D., of the UB School of Social Work.
The study was supported in part by a grant from the National Institute on Alcohol Abuse and Alcoholism.