Significant inverse association of equol-producer status with coronary artery calcification but not dietary isoflavones in healthy Japanese men.

Equol, a metabolite of the dietary isoflavone daidzein, is produced by the action of gut bacteria in some individuals who are termed as equol-producers. It is proposed to have stronger atheroprotective properties than dietary isoflavones. We examined a cross-sectional association of dietary isoflavones and equol-producer status with coronary artery calcification (CAC), a biomarker of coronary atherosclerosis, among men in Japan. A population-based sample of 272 Japanese men aged 40-49 years recruited from 2004 to 2007 was examined for serum isoflavones, serum equol, CAC and other factors. Equol-producers were classified as individuals having a serum level of equol >83 nm. The presence of CAC was defined as a coronary Ca score ≥10 Agatston units. The associations of dietary isoflavones and equol-producers with CAC were analysed using multiple logistic regression. The median of dietary isoflavones, equol and CAC were 512·7 (interquartile range (IQR) 194·1, 1170·0), 9·1 (IQR 0·10, 33·1) and 0·0 (IQR 0·0, 1·0) nm, respectively. Prevalence of CAC and equol-producers was 9·6 and 16·0 %, respectively. Dietary isoflavones were not significantly associated with CAC. After multivariable adjustment, the OR for the presence of CAC in equol-producers compared with equol non-producers was 0·10 (95 % CI 0·01, 0·90, P<0·04). Equol-producers had significantly lower CAC than equol non-producers, but there was no significant association between dietary isoflavones and CAC, suggesting that equol may be a key factor for atheroprotective properties of isoflavones in Japanese men. This finding must be confirmed in larger studies or clinical trials of equol that is now available as a dietary supplement.

Progression of coronary artery calcium in Japanese American men and white men in the ERA JUMP study.

BACKGROUND: Progression of coronary artery calcium (CAC) is associated with increased risk of coronary heart disease (CHD) and is reported to be greater in whites than blacks, Hispanics, and Chinese in the US. Our objective was to compare progression of CAC between Japanese Americans and whites. METHODS: Population-based sample of 303 Japanese American men and 310 white men aged 40-49years, free of clinical cardiovascular disease at baseline, were examined for CAC at baseline (2004-2007) and follow-up (2008-2013). Progression of CAC was defined as change in coronary calcium scores (CCS) in participants with baseline CCS>0 and incident CAC in participants with baseline CCS=0. Multiple linear regression and relative risk regression were used to compare change in CCS scores and incident CAC between the two races, respectively. RESULTS: Japanese American men had significantly greater annual change in CCS than white men (median [interquartile range]: 11.3 Agatston units [1.4, 24.9] vs 2.5 [-0.22, 14.5]) in the unadjusted analyses. After adjusting for cardiovascular risk factors and follow-up time, change in CCS (beta±CI) and incidence rate ratio of CAC was similar in Japanese American men and white men: -0.12 (-0.34, 0.15) and (0.87 [95% CI: 0.20, 3.9]), respectively. CONCLUSIONS: In contrast to previously reported greater progression of CAC in whites than other races, we found a similar progression of CAC in Japanese American men as white men. Our study identifies Japanese American men as a target group for prevention of CHD. Large prospective studies are warranted to confirm these findings.