A study presented at the European Society of Cardiology Congress shows that drinking three or more cups of caffeinated espresso per day may increase blood pressure and blood glucose levels. The Hypertension and Ambulatory Recording Venetia Study (HARVEST) began in Italy in 1990 and recruited more than 1,000 patients, aged 18–45, who had stage 1 hypertension and did not have diabetes.
Enrolled participants underwent ambulatory blood pressure monitoring and three office-based measurements were repeated at 1, 2, 3, and 6 months, and at 6-month intervals thereafter. The endpoint was hypertension requiring any antihypertensive treatment according to international guidelines. During the study, 24-hr urine samples were collected to assess catecholamine levels. Lifestyle factors such as body weight, physical activity, smoking status, and blood glucose were measured. Patients underwent echocardiography.
They were divided into three groups according to their caffeinated coffee intake: 316 (26%) were designated as abstainers because they did not drink coffee; 767 (64%) drank 1–2 cups a day and were categorized as moderate drinkers; and 119 (10%) drank three or more cups of coffee a day and were defined as heavy drinkers.
The researchers found that in multivariate analysis, coffee consumption was a significant predictor for developing hypertension that required antihypertensive therapy, with a hazard ratio (HR) of 1.5 for heavy drinkers and 1.1 for moderate drinkers, compared to abstainers. The difference was significant only for heavy coffee consumption.
In addition, heavy coffee consumption was a predictor of future prediabetes. The incidence of prediabetes was highest in the heavy coffee drinkers and significantly predicted the risk of developing prediabetes compared to abstainers.
There was a significant linear relationship found after multivariate adjustment between coffee intake and cardiovascular events such as heart attacks, with the risk increasing with higher coffee intake. Even moderate coffee intake, defined as one to three cups per day, could up the risk of a cardiovascular event when compared to that of non–coffee drinkers.
