Polycystic ovary syndrome: relationship between insulin sensitivity, sex hormone levels and ovarian stromal blood flow

Polycystic ovary syndrome (PCOS) is the most common cause of menstrual diso rders, and is characterized by chronic anovulation, hyperandrogenism and in fertility. In recent years, it has become apparent that PCOS is also associ ated with hyperinsulinemia that is probably central to the pathogenesis of PCOS. As a peculiar vascular pattern has been reported to be present in PCO S, the aim of this study was to investigate intraovarian stromal vasculariz ation in PCOS patients and its possible correlation with sex hormones, gona dotropins and insulin levels. Twenty-eight oligomenorrheic or amenorrheic patients with PCOS and 14 eumen orrheic women with a PCOS-like ovarian pattern undergoing endoctrine screen ing and ultrasound color Doppler intraovarian blood flow were recruited to the study. Ten healthy women with regular menses represented the control gr oup. Hormonal assays (follicle-stimulating hormone (FSH), luteinizing hormone (L H), androstenedione, testosterone, sex hormone-binding globulin (SHBG) and estradiol), oval glucose tolerance test (OGTT), baseline and glucose-induce d insulin levels, and transvaginal ultrasonographic and color Doppler analy sis (pulsatility index (PI), resistance index (RI) and velocity (V-max) of ovarian stromal flow) were performed in all participants in the early proli ferative phase. Endocrine values showed significant differences in PCOS pat ients compared with PCOS-like women and controls, while PI and RI indices w ere signifcantly higher in controls. PCOS patients were divided into hyperi nsulinemic (n = 16) and normoinsulinemic (n = 12). Androstenedione was sign ificantly higher (p < 0.01) in the hyperinsulinemic than in the normoinsuli nemic patients and controls, while SHBG was significantly (p < 0.01) lower in the hyperinsulinemic group. Analysis of color Doppler intraovarian vascu larization showed a significantly lower RT and a higher V-max in the hyperi nsulinemic subjects than in the normoinsulinemic PCOS patients and controls . An increased stromal blood flow was observed in the PCOS and PCOS-like pati ents by transvaginal color Doppler evaluation, but this technique is not ab le to differentiate these two similar ovarian patterns. However, hyperinsul inemic PCOS patients had an increased vascularity of the ovarian stroma. A strong correlation between hyperinsulinemia, hyperandrogenism and low SHBG levels tvas evidenced, and a hyperinsulinemia-induced mechanism far ovarian stromal angiogenesis is discussed.