Risk Factor Effects and Total Mortality in Older Japanese Men in Japan and Hawaii

Abstract

We sought to identify factors related to total mortality in older Japanese men in Japan and Hawaii. Baseline data were collected from 1980 to 1982 in 1379 men in Hawaii and 954 men in Japan. Ages ranged from 61 to 81 years, with mortality follow-up during a 19-year period. Compared with Japan, men in Hawaii had a 2-fold excess of diabetes and a 4-fold excess of prevalent coronary heart disease (P < .001). Total cholesterol and body mass index were also greater in Hawaiian men (P < .001). In contrast, men in Japan had greater systolic blood pressure and were nearly 3 times more likely to smoke cigarettes (P < .001). Although each cohort had elements of a poor risk factor profile, there was a 1.4-fold excess in the risk of death in Japan (49.4 vs. 36.2/1,000 person-years, P < .001). Although mortality was similar after risk factor adjustment, only blood pressure and cigarette smoking accounted for the higher risk of death in Japan. Cigarette smoking and hypertension explain much of the excess mortality in Japan versus Hawaii. In this comparison of genetically similar cohorts, evidence further suggests that Japanese in Japan are equally susceptible to develop the same adverse risk factor conditions that exist in Hawaii.