Male Reproductive Endocrine Hormone Disturbance Of Exposure To Phytoestrogens

PartⅠDetermination of phytoestrogen metabolite in human urineTo establish a high sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analytical methods for the determination of phytoestrogens (PEs) and their metabolites in urine which including dadzein (DAD), genistin(GEN), equol(EQU), coumestrol(COU), naringenin(NAR), secoisolariciresinol(SEC), enterodiol(END) and enterolactone(ENT). The human urine was processed by enzymatic hydrolysis using beta-glucuronidase and liquid-liquid extraction, and determined by LC-MS/MS. Between the concentration range of 0.8-3000μg/L of urine sample, all compounds give good linearity and the linear correlation coefficient is over 0.99. The recovery is between 82.8 and 106.3%. The within-day precision and the day to day precision are 3.2~10.3% and 4.2~13.4% respectively. Conclusion: This method can be used for determination of PEs and its metabolites in human urine with a stable recovery, good reproducibility and low detection limit. PartⅡRelationship between PEs levels and male reproductive hormones among non-occupational exposure malesIn the present study, we explored the association between serum reproductive hormone levels and urinary CR adjusted concentration of phytoestrogens (which contains DAD, GEN, EQU, COU, NAR, SEC, END and ENT), in Chinese adult men. Study subjects (n=948) were from the affiliated hospitals of Nanjing Medical University. By using UPLC-MS/MS, urinary PEs level of each subject were measured and adjusted by urinary CR. Blood samples were collected for measuring serum levels of reproductive hormones, including FSH, LH, E2, T and PRL. The median concentration of DAD, GEN, EQU, COU, NAR, SEC, END and ENT is 17.13, 88.82, 0.55, 74.39, 11.43, 69.36, 16.87 and 4.87μg/g?CR, respectively. There were suggestive association between some increased CR-adjusted PEs and reproductive hormone levels. These observed associations between PEs levels and some altered hormone level indicated the reproductive effects on adult men of PEs exposure.PartⅢRelationship between PEs levels and thyroid hormone levels among non-occupational exposure malesIn the present study, we explored the association between serum thyroid hormone levels and urinary CR adjusted concentration of PEs, in Chinese adult men. A population of 486 Chinese males was recruited. Using UPLC-MS/MS, eight PEs including DAD, GEN, EQU, COU, NAR, SEC, END and ENT were measured in spot urinary samples which were adjusted by urinary creatinine (CR). Blood samples were collected for measuring serum levels of thyroid hormones including total thyroxine (T4), free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH). There were suggestive association between increased CR-adjusted SEC/END and abnormal thyroid hormone levels. These results indicated that PEs exposure might be related to altered male thyroid hormone levels, but further study is needed to confirm these observed findings.PartⅣRelationship betweenPEs levels and male idiopathic infertility in Chinese non-occupational exposure adult malesLimited studies have suggested that male reproductive function might be associated with exposure to PEs. We recruited 1077 males in this study, through eligibility screening procedures. Individual exposures to PEs were measured as spot urinary concentrations of eight PEs(including DAD, GEN, EQU, COU, NAR, SEC, END and ENT), which were adjusted by urinary creatinine (CR). Subjects with idiopathic infertility were further divided into'normal'and'abnormal'semen quality groups based on their semen volume, sperm concentration, sperm number per ejaculum and sperm motility. Subjects with higher urinary concentrations of SEC, GEN, DAD (assessed as quintiles) were more likely to have idiopathic male infertility. Subjects with higher urinary concentrations of END and ENT (assessed as quintiles) were less likely to have idiopathic male infertility. Thus, increased urinary concentrations of some PEs were associated with male idiopathic infertility risks.