Trends in coronary risk factors and electrocardiogram findings from 1977 to 2009 with 10-year mortality in Japanese elderly males – The Tanushimaru Study

Abstract Background An understanding of the trends in regard to coronary risk factors and electrocardiogram (ECG) findings has an important role in public health. We investigated the trends in coronary risk factors and main ECG findings in 1977, 1989, 1999, and 2009 in the Japanese cohort of the Seven Countries Study, in Tanushimaru, a typical farming town on Kyushu Island. Methods and results A total of 1397 subjects (231 in 1977, 332 in 1989, 389 in 1999, and 445 in 2009) were enrolled in this study, and all of them were males aged over 65 years. In coronary risk factors, total cholesterol levels, diastolic blood pressure, body mass index, and uric acid significantly increased during these 3 decades. The prevalence of smokers markedly decreased from 56.7% in 1977 to 16.8% in 2009. ECG changes during 3 decades were wider QRS interval, increased prevalence of major abnormality, reduced heart rate, shortened PR interval and corrected QT, and decreased prevalence of left ventricular hypertrophy. Age, smoking habits, major and minor abnormalities in ECG were associated with mortality in 1977–1987. Age, total cholesterol levels (inversely) and corrected QT were associated with mortality in 1989–1999. Age, smoking habits, heart rate, and systolic blood pressure were associated with mortality in 1999–2009. Conclusions Predictors of mortality have changed with the times. Coronary risk factors such as smoking, increased heart rate, and elevated blood pressure have been recently associated with mortalities in elderly male Japanese general population.