Coffee consumption and risk of cardiovascular events in hypertensive patients. Results from the HARVEST

Abstract

Background: Controversy still exists about the long-term cardiovascular effects of coffee consumption in hypertension.

Methods: The predictive capacity of coffee use for cardiovascular events (CVEs) was investigated in 1204 participants from the HARVEST, a prospective cohort study of non-diabetic subjects aged 18-45years, screened for stage 1 hypertension. Subjects were grouped into three categories of coffee drinking, non-drinkers (none), moderate drinkers (1 to 3cups/day) and heavy drinkers (4or more cups/day). Multivariate Cox proportional hazards models were developed adjusting for possible confounding variables and risk factors.

Results: During a median follow-up of 12.6years, CVEs were developed by 60 participants. CVEs were more common among coffee drinkers than abstainers (abstainers, 2.2%; moderate drinkers, 7.0%; heavy drinkers, 14.0%; p for trend=0.0003). In a multivariable Cox regression model, coffee use was a significant predictor of CVE in both coffee categories, with a hazard ratio of 2.8 (95% CI, 1.0-7.9) in moderate coffee drinkers and of 4.5 (1.4-14.2) in heavy drinkers compared to abstainers. After inclusion of change in body weight (p=ns), incident hypertension (p=0.027) and presence of diabetes/prediabetes (p=ns) at follow-up end, the association with CVE was attenuated but remained significant in heavy coffee drinkers (HR, 95% CI, 3.4, 1.04-11.3).

Conclusions: These data show that coffee consumption increases the risk of CVE in a linear fashion in hypertension. This association may be explained in part by the association between coffee and development of hypertension. Hypertensive patients should be discouraged from drinking coffee.

Keywords: Caffeine; Cardiovascular; Coffee; Events; Hypertension.