0454 GMT August 22, 2019
The 12-year study in more than 1, 200 patients found that heavy coffee drinkers had a four-fold increased risk while moderate drinkers tripled their risk. Future prediabetes attenuated the associations suggesting that the effect of coffee on cardiovascular events may be mediated by its long term influence on blood pressure and glucose metabolism, Medical Xpress said.
"There is controversy surrounding the long-term cardiovascular and metabolic effects of coffee consumption in patients with hypertension," said Mos. "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 study included 1,201 non-diabetic patients aged 18 to 45 years from the prospective HARVEST study who had untreated stage one hypertension.
There was a linear relationship between coffee use and risk of hypertension needing treatment. The association reached statistical significance for heavy drinkers. 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 prediabetes. A linear relationship was found, with a 100 percent (30 percent to 210 percent) increased risk of prediabetes in the heavy coffee drinkers.
"Drinking coffee increases the risk of prediabetes in young adults with hypertension who are slow caffeine metabolizers," said Mos. "Slow caffeine metabolizers 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 prediabetes depends on the amount of daily coffee intake and genetic background."
During the 12.5-year follow-up, there were 60 cardiovascular events. Of these, about 80 percent were heart attacks and the remainder included strokes, peripheral artery disease and kidney failure.
Mos concluded: "Our study shows that coffee use is linearly associated with increased risk of cardiovascular events in young adults with mild hypertension. This relationship seems to be at least partially mediated by the long-term effect of coffee on blood pressure and glucose metabolism. 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."