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

Abstract

Polycystic ovary syndrome (PCOS) is the most common cause of menstrual disorders, and is characterized by chronic anovulation, hyperandrogenism and infertility. In recent years, it has become apparent that PCOS is also associated with hyperinsulinemia that is probably central to the pathogenesis of PCOS. As a peculiar vascular pattern has been reported to be present in PCOS, the aim of this study was to investigate intraovarian stromal vascularization in PCOS patients and its possible correlation with sex hormones, gonadotropins and insulin levels. Twenty-eight oligomenorrheic or amenorrheic patients with PCOS and 14 eumenorrheic women with a PCOS-like ovarian pattern undergoing endoctrine screening and ultrasound color Doppler intraovarian blood flow were recruited to the study. Ten healthy women with regular menses represented the control group. Hormonal assays (follicle-stimulating hormone (FSH), luteinizing hormone (LH), androstenedione, testosterone, sex hormone-binding globulin (SHBG) and estradiol), oval glucose tolerance test (OGTT), baseline and glucose-induced insulin levels, and transvaginal ultrasonographic and color Doppler analysis (pulsatility index (PI), resistance index (RI) and velocity (V-max) of ovarian stromal flow) were performed in all participants in the early proliferative phase. Endocrine values showed significant differences in PCOS patients compared with PCOS-like women and controls, while PI and RI indices were signifcantly higher in controls. PCOS patients were divided into hyperinsulinemic (n = 16) and normoinsulinemic (n = 12). Androstenedione was significantly higher (p < 0.01) in the hyperinsulinemic than in the normoinsulinemic patients and controls, while SHBG was significantly (p < 0.01) lower in the hyperinsulinemic group. Analysis of color Doppler intraovarian vascularization showed a significantly lower RT and a higher V-max in the hyperinsulinemic subjects than in the normoinsulinemic PCOS patients and controls. An increased stromal blood flow was observed in the PCOS and PCOS-like patients by transvaginal color Doppler evaluation, but this technique is not able to differentiate these two similar ovarian patterns. However, hyperinsulinemic 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

Efficacy of exenatide on weight loss, metabolic parameters and pregnancy in overweight/obese polycystic ovary syndrome

“…These changes could be due to a reduction in their circulating insulin. This finding is in accordance with previous studies showing that insulin has a strong negative effect on SHBG, further limiting peripheral androgen bioavailability . Another study reported that the state of relative IR is related to the suppression of SHBG in the liver .…”

Serum levels of TSP‐1, NF‐κB and TGF‐β1 in polycystic ovarian syndrome (PCOS) patients in northern China suggest PCOS is associated with chronic inflammation

“…Insulin and insulin‐like growth factor‐1 (IGF‐1) receptors are found in ovarian tissue, and thus, insulin may directly stimulate ovarian tissue . High insulin levels may inhibit the expressions of IGF‐binding protein (IGFBP) and SHBG in the liver, thus increasing serum‐free testosterone, and high insulin levels may also stimulate adrenal P450c17 hydroxylase to increase adrenal androgens leading to hyperandrogenism in PCOS . Patients with IR are more likely to be obese and have lower LH and testosterone levels and a lower LH/FSH ratio, and it has been suggested that these patients have defective autophosphorylation of the insulin receptor, which may be a mechanism for IR in PCOS .…”

A Case-controlled Comparative Hospital-based Study on the Clinical, Biochemical, Hormonal, and Gynecological Parameters in Polycystic Ovary Syndrome

“…PCOS women showed increased levels of insulin. High basal insulin levels (35.7%) were reported in a study carried out with seventy women with PCOS in the age range 12-35 y of age [31] . Increased concentration of insulin binds to insulin growth factor 1 (IGF-1) receptor of theca cells leading to increased levels of androstenedione and HA [32] .…”