Abstract WP192: Secular Trends in the Incidence, Mortality and Survival Rates of Cardiovascular Disease in a General Japanese Population: the Hisayama Study, 1961-2009

Abstract

Background: Changes in lifestyle and advances in medical technology during the past half century have been likely to affect the incidence and mortality of cardiovascular diseases and the prevalence of their risk factors in Japan. Methods: We established 5 cohorts consisting of residents of the town of Hisayama, Fukuoka, Japan, aged 40 years or older without a history of cardiovascular disease in 1961, 1974, 1983, 1993, and 2002. Each cohort was followed up for 7 years. Results: The age-adjusted incidence and mortality rates of ischemic stroke decreased significantly in men and women over the past half century. These decreasing trends were the greatest in the earlier period (from the 1960s to the 1970s) and slowed down in the recent period (from the 1980s to the 2000s). The incidence and mortality of intracerebral hemorrhage decreased significantly in men but not in women. The incidence and mortality of coronary heart disease decreased in women, but did not show a clear change in men. Five-year survival rates of stroke and acute myocardial infarction increased significantly with time. While the prevalence of hypertension did not show a drastic secular change, the proportion of individuals with antihypertensive treatment increased consistently, and mean systolic and diastolic blood pressures among hypertensive participants significantly decreased over the study period. On the other hand, the prevalence of glucose intolerance, hypercholesterolemia, and obesity increased steeply. Conclusions: The incidence and mortality rates of ischemic stroke in both sexes, intracerebral hemorrhage in men, and coronary heart disease in women decreased significantly, probably owing to better management of hypertension. However, the decreasing trends in ischemic stroke slowed down recently and there was no clear change for coronary heart disease in men, probably because the benefits of hypertension control were negated by increasing prevalence of metabolic risk factors. In addition to strict control of hypertension, urgent management of metabolic disorders is needed for further prevention of cardiovascular disease in Japan.