Endocrine Abstracts

JOINT2757

Background: Polycystic ovary syndrome (PCOS) is a common endocrine condition of heterogeneous origin, characterized by hyperandrogenism, oligo-/amenorrhoea, and/or polycystic ovarian morphology. PCOS phenotypes are associated with several comorbidities including depression, obesity and insulin resistance. Isoflavones are plant-derived hormones (phytoestrogens) with similar chemical structure and properties like estrogens. Soy products, among other nutrients, contain clinically relevant concentrations of isoflavones such as genistein and daidzein. The ability to derive health benefits from a soy-based nutrition is thought to depend on the production of the isoflavone metabolite equol, based on specific human gut bacteria. Equol has been shown to bind to estrogen-receptors alpha and beta and to have anti-androgenic, anti-cancer and anti-inflammatory effects and is therefore of particular interest for women with PCOS. However, in Western countries, only 25-30% of the population are so-called “equol-producers” and have the appropriate bacteria to convert daidzein to equol. The prevalence in women with PCOS was reported to be even lower. The present interim analysis of the Isoflavone Study aimed to assess potential differences in the prevalence of equol-producers among women with PCOS, healthy women and healthy men.

Methods: After a one-day consumption of 2x200 ml soy drink, equol and daidzein concentrations in the morning urine of the following day were measured by gas chromatography and mass spectrometry (GC-MS) in the women enrolled with PCOS (n = 33), in control women (n = 13) and men (n = 45). A cut-off value for the log10-transformed urinary equol:daidzein ratio of -1.75 was used to define equol production.

Results: Prevalence of equol-producers was 38.5% in the PCOS-group, 40.0% in healthy women and 27.9% in men. The frequency of equol producers did not differ across the groups, nor between women with PCOS and the control group, nor between women with PCOS and men. Equol-daidzein ratio was -1.9 ± 0.8 in women with PCOS, -1.8 ± 0.8 in the control group and -2.0 ± 0.8 in the group of men.

Conclusion: Equol producer prevalence in Western countries is around 30-40%. In our interim analysis, we found no significant differences among women with PCOS, healthy women, and healthy men. Similarly, the equol-daidzein ratio did not show meaningful variation between the groups. However, due to the limited sample size, these results should be interpreted with caution. A final analysis after full recruitment is necessary to confirm these first findings and to provide more robust conclusions.