Associations between Inflammatory Markers and Subclinical Atherosclerosis in Middle-aged White, Japanese-American and Japanese Men: The ERA-JUMP Study.

AIM: To examine whether the inflammatory markers C-reactive protein (CRP) and fibrinogen are associated with biomarkers of atherosclerosis [carotid intima-media thickness (IMT) and coronary artery calcification (CAC)] in the general male population, including Asians. METHODS: Population-based samples of 310 Japanese, 293 Japanese-American and 297 white men 40-49 years of age without clinical cardiovascular disease underwent measurement of IMT, CAC and the CRP and fibrinogen levels as well as other conventional risk factors using standardized methods. Statistical associations between the variables were evaluated using multiple linear or logistic regression models. RESULTS: The Japanese group had significantly lower levels of inflammatory markers and subclinical atherosclerosis than the Japanese-American and white groups (P-values all ＜0.001). The mean level of CRP was 0.66 vs. 1.11 and 1.47 mg/L, while that of fibrinogen was 255.0 vs. 313.0 and 291.5 mg/dl, respectively. In addition, the mean carotid IMT was 0.61 vs. 0.73 and 0.68 mm, while the mean prevalence of CAC was 11.6% vs. 32.1% and 26.3%, respectively. Body mass index (BMI) showed significant positive associations with both the CRP and fibrinogen levels. Although CRP showed a significant positive association with IMT in the Japanese men, this association became non-significant following adjustment for traditional risk factors or BMI. In all three populations, CRP was not found to be significantly associated with the prevalence of CAC. Similarly, fibrinogen did not exhibit a significant association with either IMT or the prevalence of CAC. CONCLUSIONS: The associations between inflammatory markers and subclinical atherosclerosis may merely reflect the strong associations between BMI and the levels of inflammatory markers and incidence of subclinical atherosclerosis in both Eastern and Western populations.

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.