Do differences in risk factors explain the lower rates of coronary heart disease in Japanese versus U.S. women?
BACKGROUND
Mortality from coronary heart disease (CHD) in women in Japan is one of the lowest in developed countries. In an attempt to shed some light on possible reasons of lower CHD in women in Japan compared with the United States, we extensively reviewed and analyzed existing national data and recent literature.


METHODS
We searched recent epidemiological studies that reported incidence of acute myocardial infarction (AMI) and examined risk factors for CHD in women in Japan. Then, we compared trends in risk factors between women currently aged 50-69 years in Japan and the United States, using national statistics and other available resources.


RESULTS
Recent epidemiological studies have clearly shown that AMI incidence in women in Japan is lower than that reported from other countries, and that lipids, blood pressure (BP), diabetes, smoking, and early menopause are independent risk factors. Comparing trends in risk factors between women in Japan and the United States, current levels of serum total cholesterol are higher in women in Japan and levels have been similar at least since 1990. Levels of BP have been higher in in Japan for the past 3 decades. Prevalence of type 2 diabetes has been similar in Japanese and white women currently aged 60-69 for the past 2 decades. In contrast, rates of cigarette smoking, although low in women in both countries, have been lower in women in Japan.


CONCLUSIONS
Differences in risk factors and their trends are unlikely to explain the difference in CHD rates in women in Japan and the United States. Determining the currently unknown factors responsible for low CHD mortality in women in Japan may lead to new strategy for CHD prevention.
1 Department of Epidemiology, University of Pittsburgh , Pittsburgh Pennsylvania.
Akira
A
Sekikawa
Bradley J
BJ
Willcox
Takeshi
T
Usui
John Jeffrey
JJ
Carr
Emma J M
EJ
Barinas-Mitchell
Kamal H
KH
Masaki
Makoto
M
Watanabe
Russell P
RP
Tracy
Marianne H
MH
Bertolet
Rhobert W
RW
Evans
Kunihiko
K
Nishimura
Kim
K
Sutton-Tyrrell
Lewis H
LH
Kuller
Yoshihiro
Y
Miyamoto
D000328:Adult; D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D003327:Coronary Disease / Q000208:ethnology* / Q000209:etiology / Q000401:mortality; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
D002784:Cholesterol