Is there a role for soy isoflavones in the therapeutic approach to polycystic ovary syndrome? Results from a pilot study.

OBJECTIVE: To evaluate the effect of the soy isoflavone genistein on the metabolic and hormonal disturbances of polycystic ovary syndrome (PCOS), we studied a group of obese, hyperinsulinemic, and dyslipidemic women presenting this syndrome during 6 months of phytoestrogen administration.
DESIGN: Pilot prospective study.
SETTING: Operative division of endocrinological gynecology in a university hospital. PATIENT(S): Twelve Caucasian obese, hyperinsulinemic, and dyslipidemic women with PCOS. INTERVENTION(S): Patients received 36 mg/d of genistein for 6 months. Ultrasonographic pelvic exams, hormonal and lipid features, oral glucose tolerance test, and euglycemic hyperinsulinemic clamp were performed at baseline and after 3 and 6 months of treatment. MAIN OUTCOME MEASURE(S): Basal hormonal assays, lipid profile, and glycoinsulinemic assessment. RESULT(S): Phytoestrogens supplementation significantly improved total cholesterol levels, reducing low-density lipoprotein (LDL) cholesterol and resulting in a significant decrease in the LDL-high-density lipoprotein ratio (LDL-HDL). Triglycerides showed a trend toward decrease, whereas no changes were detected in very low-density lipoprotein cholesterol plasma levels. Genistein treatment did not significantly affect anthropometric features, the hormonal milieu, and menstrual cyclicity. No significant changes occurred in glycoinsulinemic metabolism. CONCLUSION(S): The possible advantages derived from the therapeutic use of phytoestrogens in PCOS are limited to improvement of the lipidic assessment.