ABSTRACT

It is well known that subjects with metabolic syndrome show an elevated resting heart rate. We previously reported that elevated heart rate was significantly related to all-cause mortality, and that coffee consumption was inversely associated with metabolic syndrome. We hypothesized that higher coffee consumption may decrease all-cause mortality by reducing resting heart rate. We performed a longitudinal epidemiological study in Tanushimaru (a cohort of the Seven Countries Study). A total of 1920 residents aged over 40 years received health check ups in 1999. We measured components of metabolic syndrome, and eating and drinking patterns were evaluated by a food frequency questionnaire. We followed up the participants annually for 15 years. During the follow-up period, 343 of the participants died. Of these, 102 subjects died of cancer, 48 of cerebro-cardiovascular diseases, and 44 of infectious diseases. Multivariate analyses revealed that higher coffee consumption was inversely associated with resting heart rate. Kaplan-Meier curves found lower mortality rates in the higher coffee consumption groups. In the lower coffee consumption groups, elevated hazard ratios of all-cause death were observed in the increased heart rate quintiles, whereas heart rate was not associated with all-cause death in the higher coffee consumption groups. These significant associations remained after further adjustment for confounders. This prospective study suggests that higher coffee consumption may have a protective effect against all-cause death due to reducing resting heart rate.