Endocrine Abstracts

Polycystic Ovary Syndrome (PCOS) is the most common endocrinological dysfunction among women of reproductive age, often featuring hyperandrogenemia and anovulation. Reciprocal effects exist between elevated LH, androgens, anovulation and other features, increasing the hormonal disbalance, while the origins of PCOS are still not fully clear. The neuropeptides Phoenixin-20 (PNX20) and Nesfatin1 (NES1) are being co-expressed and thought to play opposing roles in the hypothalamic–pituitary–gonadal axis. PNX20 seems to regulate pituitary LH secretion and to be elevated in PCOS. NES1 is involved in metabolism and inflammation. This study characterized changes of PNX20 and NES1 within cycles of PCOS patients with anovulation, ovulation and progestin administration.

Methods: Women of reproductive age with PCOS, diagnosed according to the Rotterdam Criteria were included in this observational study after informed consent. All women had a clinical indication for a progestin test, conducted with 10 mg dydrogesterone daily for 14 days in the second half of the first menstrual cycle. For observational purposes 5 blood samples were taken from each participant, on day 3 - 7 of the menstrual cycle and 14 - 19 days later, spanning two and a half consecutive menstrual cycles – one under dydrogesterone and 1.5 cycles thereafter. Follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, testosterone, dehydroepiandrosterone-sulfate (DHEAS), prolactin, and sexual hormone binding globulin (SHBG) were measured.

Results: 40 complete cycles in 26 patients were analyzed. 20 cycles were anovulatory, 20 ovulatory-marked by a progesterone increase over 5.8 ng/ml. A linear association was found between PNX20 and LH levels and significant (P<0.05) differences in anovulatory cycles were noted between follicular phase (mean PNX20 = 1.89 ng/ml ± 1.16 ng/ml) and the second half of the cycle (mean PNX20 = 2.90 ng/ml ± 1.52 ng/ml). Pearson’s coefficient between progesterone and PNX20 was -0.551 (P<0.05). In the follicular and luteal phase of ovulatory cycles, the difference was not significant. By contrast, NES1 levels only differed significantly between phases of ovulatory cycles (mean follicular NES1 = 1.83 ng/ml ± 1.20 ng/ml, mean luteal NES1= 2.16 ng/ml ± 1.22 ng/ml). Exogenous progestin administration at the dose administered had no significant influence on PNX20 or NES1 levels. We conclude that endogenous progesterone and/or ovulation itself may be important modulators of PNX20 and NES1. This opens different explanation models as to why PNX20 is elevated amongst PCOS patients.