Prognostic cardiovascular cut-off values of dietary caffeine in a cohort of unselected men and women from general population

Abstract

Background and aimsAmong an unselected cohort of men and women from general population (n = 1.668), the prognostic effects of being over the cut-off of all-source dietary caffeine intake were studied. Methods and resultsPrognostic cut-off values for coronary events, incident heart failure (HF), cerebrovascular events (CBV) and arrhythmic events (ARR) were found by means of the receiver-operating-characteristic curves method. Those for HF (>230 mg/day), for CBV (>280 mg/day) and for ARR (>280 mg/day) were confirmed in multivariate Cox analysis adjusted for age, body mass index, circulating thyroid hormone, diabetes mellitus, arterial hypertension, smoking, dietary intake of ethanol, basal heart rate, low-density-lipoprotein cholesterol, forced expiratory volume in 1 s and β-blocking therapy. Being over these cut-off values was associated to a reduced hazard ratio during the follow-up in the whole cohort (HR 0.678, 95%CI 0.567–0.908, p = 0.009 for HF; 0.651, 95%CI 0.428–0.994, p = 0.018 for CBV; 0.395, 95%CI 0.395–0.933, p = 0.022 for ARR) and in men (0.652, 0.442–0.961, p = 0.029; 0.432, 0.201–0.927, p = 0.03; 0.553, 0.302–1.000, p = 0.05, respectively) but not in women. The caffeine-induced risk decrease observed in the whole cohort is therefore entirely attributable to men. In the case of HF, heart rate entered the risk equation in a positive manner without rejecting caffeine. The –163C>A polymorphism of the CYP1A2 gene, codifying for ability to metabolize caffeine, introduced in sensitivity analysis, did not alter the prognostic models. ConclusionMen introducing >230 mg/day caffeine show a reduced risk of HF, and those introducing >280 mg/day a reduced risk of CBV and ARR independent of genetic pattern.