The greatest increase in risk for heart events was seen in people who drink more than 4 cups of coffee a day. Photo by Boumen Japet/Shutterstock
LONDON, Sept. 1 (UPI) -- Young adults with high blood pressure who drink 4 or more cups of coffee per day are 4 times as likely to have a cardiovascular event as those who abstain from the beverage, according to a 12-year study in Italy.
The risk was found to be strongest for heavy drinkers, however coffee consumption overall was found to increase the risk with researchers seeing a three-fold increase for moderate drinkers, who were defined as having 1 to 3 cups per day.
"There is controversy surrounding the long term cardiovascular and metabolic effects of coffee consumption in patients with hypertension," said Dr. Lucio Mos, a cardiologist at Hospital of San Daniele del Friuli, in a press release. "Our study was designed to evaluate whether coffee drinking had an effect on the risk of cardiovascular events, and if the association was mediated by effects on blood pressure and glucose metabolism."
The research, presented at the 2015 congress of the European Society of Cardiology, included data on 1,201 non-diabetic people between the ages of 18 and 45 with untreated stage 1 hypertension who participated in the 12-year HARVEST study in Italy.
Coffee consumption was split into three categories: Non-drinkers, moderate drinkers who had 1 to 3 cups per day, and heavy drinkers who consume 4 or more cups per day. Most participants were moderate drinkers, 62.7 percent, while 26.3 percent were non-drinkers and 10 percent were heavy drinkers.
During the 12-year follow-up period after the initial HARVEST survey, researchers reported 60 cardiovascular events, 80 percent of which were heart attacks. Other events included included strokes, peripheral artery disease and kidney failure.
The researchers found, based on the data, that heavy coffee drinkers were 4.3 times more likely than non-drinkers to experience some type of cardiovascular event and moderate drinkers were 2.9 times more likely.
When considering the data, researchers said they also factored in other information about participants, including lifestyle factors, age, sex, parental cardiovascular morbidity, BMI, total blood cholesterol, 24-hour ambulatory blood pressure, and 24-hour ambulatory heart rate.
High blood pressure often can lead to the development of type 2 diabetes, with the researchers finding a 100 percent increased risk for diabetes in the survey's heavy drinkers of coffee.
"Our study shows that coffee use is linearly associated with increased risk of cardiovascular events in young adults with mild hypertension," Mos said. "These patients should be aware that coffee consumption may increase their risk of developing more severe hypertension and diabetes in later life and should keep consumption to a minimum."