title: Significant inverse association of equol-producer status with coronary artery calcification but not dietary isoflavones in healthy Japanese men.
abstract: 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.
authors.affiliation: 1Department of Epidemiology,Graduate School of Public Health,University of Pittsburgh,Pittsburgh,PA 15260,USA.
authors.forename: Vasudha
authors.initials: V
authors.lastname: Ahuja
authors.affiliation: 2Department of Public Health,Shiga University of Medical Science,Japan520-2121.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Miura
authors.affiliation: 1Department of Epidemiology,Graduate School of Public Health,University of Pittsburgh,Pittsburgh,PA 15260,USA.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Vishnu
authors.affiliation: 2Department of Public Health,Shiga University of Medical Science,Japan520-2121.
authors.forename: Akira
authors.initials: A
authors.lastname: Fujiyoshi
authors.affiliation: 1Department of Epidemiology,Graduate School of Public Health,University of Pittsburgh,Pittsburgh,PA 15260,USA.
authors.forename: Rhobert
authors.initials: R
authors.lastname: Evans
authors.affiliation: 2Department of Public Health,Shiga University of Medical Science,Japan520-2121.
authors.forename: Maryam
authors.initials: M
authors.lastname: Zaid
authors.affiliation: 2Department of Public Health,Shiga University of Medical Science,Japan520-2121.
authors.forename: Naoko
authors.initials: N
authors.lastname: Miyagawa
authors.affiliation: 2Department of Public Health,Shiga University of Medical Science,Japan520-2121.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hisamatsu
authors.affiliation: 2Department of Public Health,Shiga University of Medical Science,Japan520-2121.
authors.forename: Aya
authors.initials: A
authors.lastname: Kadota
authors.affiliation: 4Department of Preventive Medicine and Public Health,Keio University,Japan108-8345.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Okamura
authors.affiliation: 2Department of Public Health,Shiga University of Medical Science,Japan520-2121.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Ueshima
authors.affiliation: 1Department of Epidemiology,Graduate School of Public Health,University of Pittsburgh,Pittsburgh,PA 15260,USA.
authors.forename: Akira
authors.initials: A
authors.lastname: Sekikawa
mesh_terms: D000328:Adult; D050197:Atherosclerosis / Q000209:etiology / Q000378:metabolism* / Q000517:prevention & control; D001419:Bacteria / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002114:Calcinosis / Q000209:etiology / Q000517:prevention & control; D003331:Coronary Vessels / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D003430:Cross-Sectional Studies; D004032:Diet; D060754:Equol / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007529:Isoflavones / Q000097:blood / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010641:Phenotype
chemical_list: D015415:Biomarkers; D007529:Isoflavones; D060754:Equol; C004742:daidzein
keywords:  CAC coronary artery calcification;  CCS coronary calcium score; Coronary artery calcification; Equol-producers; Isoflavones; Japanese; Men