Plasma Renin Activity and Resting Heart Rate in a Population of Community-Dwelling Japanese: The Tanushimaru Study

BACKGROUND Heart rate is a strong predictor of mortality and development of obesity and diabetes. The renin-angiotensin-aldosterone system plays an important role in blood pressure control and volume homeostasis. Although many studies have indicated the association between aldosterone and hypertension or insulin resistance, epidemiological evidence of the association of heart rate with plasma renin activity (PRA) remains scant. Therefore, we investigated whether heart rate is associated with PRA. METHODS A total of 1,943 subjects were enrolled, who underwent a health examination in Tanushimaru in 2009. Plasma renin and aldosterone concentrations were measured by radioimmunoassay. PRA and the homeostasis model assessment (HOMA) were used by natural-log transformed. Resting heart rate was measured using electrocardiography. RESULTS We divided the subjects into four groups by heart rate (< 60/min, 60-69/min, 70-79/min, >= 80/ min), and analyzed an association between PRA and heart rate by analysis of covariance after adjustments for age and sex. The adjusted mean PRA and HOMA index showed a significant trend (P < 0.01) as higher heart rate, although there was no significant trend between aldosterone and heart rate (P = 0.26). In multiple linear regression analysis adjusted for age, sex, systolic blood pressure, HOMA index, and hypertensive medication, PRA was positively and strongly associated with elevated heart rate (P < 0.01). CONCLUSIONS This epidemiological study demonstrated that PRA, but not aldosterone, is significantly and positively associated with higher resting heart rate in a general population.