Too much coffee may increase CV risk in young hypertensive adults

LONDON — Drinking more than four cups of caffeinated coffee per day was associated with a fourfold higher risk for MI, stroke, peripheral artery disease and kidney failure among young adults with untreated stage 1 hypertension, according to research presented at the European Society of Cardiology Congress.

Lucio Mos, MD, presented data on 1,202 participants with untreated stage 1 hypertension (systolic BP 140-159 mm Hg and/or diastolic BP 90-99 mm Hg) and no diabetes who participated in HARVEST, a long-term, prospective study conducted at 17 hypertension units in Italy.

Based on the number of caffeine-containing cups consumed each day, 63.8% of participants were classified as moderate drinkers (one to three cups), 26.3% were classified as nondrinkers and 9.9% were classified as heavy drinkers (four or more cups). Coffee drinkers were older and had a higher BMI compared with nondrinkers.

Sixty CV events were recorded over 12 years of follow-up. Of those, approximately 80% were MI.

Heavy (HR = 4.3; 95% CI, 1.3-13.9) and moderate (HR = 2.9; 95% CI, 1.04-8.2) coffee consumption independently predicted CV events in multivariable analyses, including other lifestyle factors, age, sex, parental CV morbidity, BMI, total cholesterol, 24-hour ambulatory BP and heart rate, and changes in body weight, according to a press release.

The researchers also analyzed the long-term effect of coffee consumption on risk for prediabetes. Risk was increased by 100% among heavy coffee drinkers (range, 30% to 210%; P = .0017). However, risk for prediabetes related to coffee consumption differed according to CYP1A2 genotype, which determines whether individuals metabolize caffeine slowly or quickly, according to the release. Risk for prediabetes was increased significantly only among slow caffeine metabolizers (HR for heavy coffee drinkers = 2.78; 95% CI, 1.32-5.88).

The addition of development of hypertension to the analysis attenuated the association between coffee and CV events (heavy consumption, HR = 3.9; 95% CI, 1.2-12.5; moderate consumption, HR = 2.8; 95% CI, 0.99-7.8). After the further addition of future prediabetes, the relationship was borderline significant among heavy coffee drinkers (HR = 3.2, 95% CI, 0.94-10.9) and lost its statistical significance among moderate drinkers (HR = 2.3, 95% CI, 0.8-6.5).

“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,” Mos, cardiologist at Hospital of San Daniele del Friuli in Udine, Italy, said in the release.

During a press conference, Mos concluded, “Coffee consumption should be reduced in young- to middle-aged patients with hypertension.” – by Katie Kalvaitis

Reference:

Mos L, et al. Abstract P899. Presented at: European Society of Cardiology Congress; Aug. 29-Sept. 2, 2015; London.

Disclosure: Mos reports no relevant financial disclosures.