London, Aug 30 (IANS): If you are young and suffering from mild hypertension, it is time to shun your love for coffee. According to a research, coffee drinkers - especially those who drink over four cups a day - are at an increased risk of heart attacks and other cardiovascular events.

Not just this, heavy coffee consumption can also trigger pre-diabetes in young adults with hypertension, the study said.

The 12-year research involving more than 1,200 patients (age 18-45) found that heavy coffee drinkers had a four-fold increased cardiovascular risk while moderate drinkers had tripled risk.

"Our study shows that coffee use is linearly associated with increased risk of cardiovascular events in young adults with mild hypertension," said lead researcher Dr Lucio Mos, cardiologist at Hospital of San Daniele del Friuli in Udine, Italy.

The study included non-diabetic patients who had untreated stage 1 hypertension (systolic blood pressure between 140 and 159 mmHg and/or diastolic blood pressure between 90 and 99 mmHg).

Coffee consumption was categorised by the number of caffeine-containing cups per day: non-drinkers (0), moderate (one-three) and heavy drinkers (four or more).

As Type 2 diabetes often develops in hypertensive patients at a later stage, the study examined the long-term effect of coffee drinking on the risk of developing pre-diabetes.

A linear relationship was found, with a 100 percent (30 percent-210 percent) increased risk of pre-diabetes in the heavy coffee drinkers.

"We found that drinking coffee increases the risk of pre-diabetes in young adults with hypertension who are slow caffeine metabolisers," Dr Mos said.

Slow caffeine metabolisers have longer exposure to the detrimental effects of caffeine on glucose metabolism.

"The risk is even greater if they are overweight or obese, and if they are heavy coffee drinkers. Thus, the effect of coffee on pre-diabetes depends on the amount of daily coffee intake and genetic background," he said.

The blood pressure 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, the authors said.

The findings were presented at the ESC Congress - the annual congress of the European Society of Cardiology (ESC) - in London on August 29.