Secular trends in cardiovascular disease and its risk factors in Japanese: half-century data from the Hisayama Study (1961-2009)

Abstract

Background: Changes in lifestyle and advances in medical technology during the past half century are likely to have affected the incidence and mortality of cardiovascular disease and the prevalence of its risk factors in Japan.

Methods and results: We established 5 cohorts consisting of residents aged ≥40 years in a Japanese community, in 1961 (n=1618), 1974 (n=2038), 1983 (n=2459), 1993 (n=1983), and 2002 (n=3108), and followed up each cohort for 7 years. The age-adjusted incidence of stroke decreased greatly, by 51% in men and by 43% in women, from the 1960s to the 1970s, but this decreasing trend slowed from the 1970s to the 2000s. Among the stroke subtypes, ischemic stroke in both sexes and intracerebral hemorrhage in men showed a similar pattern. Stroke mortality decreased as a result of the decline in incidence and a significant improvement in survival rate. Although the incidence of acute myocardial infarction did not change in either sex, disease mortality declined slightly in women. From the 1960s to the 2000s, blood pressure control among hypertensive individuals improved significantly and the smoking rate decreased, but the prevalence of glucose intolerance, hypercholesterolemia, and obesity increased steeply.

Conclusions: Our findings suggest that in Japanese, the decreasing trends in the incidence of ischemic stroke have recently slowed down, and there has been no clear change in the incidence of acute myocardial infarction, probably because the benefits of hypertension control and smoking cessation have been negated by increasing metabolic risk factors.

Keywords: coronary disease; incidence; mortality; stroke; trends.