Coffee consumption and risk of hypertension: a systematic review and dose-response meta-analysis of cohort studies.

Some debates exist regarding the association of coffee consumption with hypertension risk. We performed a meta-analysis including dose-response analysis aimed to derive a more quantitatively precise estimation of this association. PubMed and Embase were searched for cohort studies published up to 18 July 2017. Fixed-effects generalized least-squares regression models were used to assess the quantitative association between coffee consumption and hypertension risk across studies. Restricted cubic spline was used to model the dose-response association. We identified eight articles (10 studies) investigating the risk of hypertension with the level of coffee consumption, including 243,869 individuals and 58,094 incident cases of hypertension. We found no evidence of a nonlinear dose-response association of coffee consumption and hypertension (P nonlinearity  = 0.243). The risk of hypertension was reduced by 2% (relative risk (RR) = 0.98, 95% confidence interval (CI) 0.98-0.99) with each one cup/day increment of coffee consumption. With the linear cubic spline model, the RRs of hypertension risk were 0.97 (95% CI 0.95-0.99), 0.95 (95% CI 0.91-0.99), 0.92 (95% CI 0.87-0.98), and 0.90 (95% CI 0.83-0.97) for 2, 4, 6, and 8 cups/day, respectively, compared with individuals with no coffee intakes. This meta-analysis provides quantitative evidence that consumption of coffee was inversely associated with the risk of hypertension in a dose-response manner.