title: [Equol-producing phenotype and in relation to serum sex hormones among healthy adults in Beijing].
abstract: OBJECTIVE
  To evaluate relations between equol-producing phenotype and serum sex hormones among adults in Beijing.
  
  
  METHODS
  90 male and 90 female adults participated in a cross-sectional study and provided twice 24h urine samples on a regular diet and after 3-d soy isoflavone challenge respectively. A health and demographics questionnaire, and 2 days food record were completed before the urine collection. Isoflavones and their metabolites in urine were measured to determine equol phenotype by HPLC.
  
  
  RESULTS
  The serum total testosterone level of the male and the serum estradiol and progesterone levels among the female participants were no significant differences between the equol producers and non-producers (P > 0.05). There were negative correlations between urinary total isoflavone, daidzein, equol, O-desmethylangolensinl, glysitein, dihydroglysitein levels and serum total testosterone concentration among the male equol producers on a regular diet (r = -0.29 - -0.36, P < 0.05). There were no significant correlations between urinary isoflavonoid excretion and serum estradiol and progesterone concentration among the female participants on a regular diet (P > 0.05), regardless of equol phenotype.
  
  
  CONCLUSIONS
  The result suggests that exposure of isoflavone is correlated with the testosterone in healthy men under the usually lifestyle, and may be related to equol phenotype.
authors.affiliation: Department of Social Medicine & Health Education, School of Public Health, Peking University, Beijing 100191, China. eddy-liu331@163.com
authors.forename: Baohua
authors.initials: B
authors.lastname: Liu
authors.forename: Liqiang
authors.initials: L
authors.lastname: Qin
authors.forename: Aiping
authors.initials: A
authors.lastname: Liu
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Shi
authors.forename: Peiyu
authors.initials: P
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D002681:China; D003430:Cross-Sectional Studies; D060754:Equol / Q000378:metabolism* / Q000652:urine; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D007529:Isoflavones / Q000008:administration & dosage / Q000652:urine*; D008297:Male; D008875:Middle Aged; D013025:Glycine max / Q000737:chemistry*; D013739:Testosterone / Q000097:blood; D055815:Young Adult
chemical_list: D012739:Gonadal Steroid Hormones; D007529:Isoflavones; D013739:Testosterone; D060754:Equol