Heart rate and mortality in a Japanese general population: An 18-year follow-up study

The predictive power of elevated heart rate for total mortality was evaluated in a Japanese general population. A total of 573 male participants, aged 40 to 64, who underwent a health examination in 1977, were followed until 1994. Heart rate (beats per minute; bpm) was measured using an electrocardiogram. During the 18 years, 82 subjects died; 18 from cerebro-cardiovascular diseases and 36 from cancer. In a multivariate proportional hazards regression model, age, elevated systolic and diastolic blood pressures, antihypertensive medication, heart rate, uric acid, vital capacity (inversely), and serum cholesterol (inversely) were significantly associated with all-cause death. Of these variables, elevated heart rate was the strongest predictor of all-cause death after adjustment for age. Resting heart rate levels were classified into five groups: <60 (G1), 60-69 (G2), 70-79 (G3), 80-89 (G4), and <greater than or equal to>90 (G5) bpm. Heart rates of 60-69 (G2) bpm showed the lowest death rate (14.3%) and heart rate greater than or equal to 90 (G5) bpm showed the highest death rate (38.2%) after adjustments for age and other confounding factors. The relative risk of G2 versus G5 was 2.68. An increased mortality risk was shown in men whose heart rate was greater than or equal to 90 bpm. Moreover, a continuous model suggested a graded increase in risk, so that risk is likely elevated even for heart rates less than 90 bpm, and lowest risk may be around 60 bpm. (C) 2001 Elsevier Science Inc. All rights reserved.