Background: Since World War II, people in Japan, South Korea, and Taiwan have been exposed to a westernized lifestyle. It is most likely that the post World War II cohorts (1950+) have been more exposed. We hypothesize that there would be an increase in mortality from coronary heart disease (CHD) in men aged 35-44 in these countries.
Methods and results: Mortality from CHD in men aged 35-44 in South Korea and Taiwan has recently increased, and in Japan it has decreased. Mortality from CHD in men aged 35-44 is lower in Japan than in either South Korea or Taiwan, and much lower than in the US. National sample data and several epidemiological studies have shown that risk factors for CHD including hypercholesterolaemia and hypertension in the past decade were not much different between young adult men in Japan and the US. Based upon these risk factors, CHD death rates among post World War II cohorts should be similar in Japan and the US. However, the rates are five times higher in the US for men aged 35-44. The majority of deaths in the category of diseases of the heart were from heart failure in men in this age group in Japan; the mortality from heart failure was about three times higher than the mortality from CHD. Heart failure was rarely used in men aged 35-44 in the US.
Conclusions: The continued low mortality rates from CHD in young men in Japan may be an artifact. It is possible that CHD death rates in post World War II birth cohort in Japan are similar to US rates.