Hormone responses to buserelin in polycystic ovary syndrome and in eumenorrheic women with hyperandrogenism/hyperandrogenemia, and the relationship of these responses with insulin resistance

We compared 37 women with polycystic ovary syndrome (PCOS) with 24 women with eumenorrhea plus hyperandrogenism and/or hyperandrogenemia without ultrasound evidence of PCO morphology (EuHyperA) to assess their hormone responses to a GnRH-agonist (buserelin). Following our recent paper on PCOS and EuHyperA, we selected patients who performed the 2 h-oral glucose tolerance test (OGTT), and stratified them according to presence/absence of insulin resistance (IR), viz. HOMA-index ≥ 2.5. IR impacted on the PCOS group since IR-yes-PCOS women had significantly higher body weight, BMI, total testosterone (TT), free androgen index (FAI), and 17-hydroxyprogesterone (17-OHP), borderline higher delta-4 androstenedione (Δ4-ASD) and ovarian volume, and significantly lower sex hormone-binding globulin (SHBG) vs IR-no-PCOS. IR-no-EuHyperA had significantly higher follicle-stimulating hormone (FSH), borderline higher dehydroepiandrosterone sulfate (DHEAS) and borderline lower 17-OHP vs IR-no-PCOS. IR-yes-EuHyperA had significantly higher DHEAS, borderline lower TT and FAI vs IR-yes-PCOS. The insulin curve was significantly higher in the IR-yes vs IR-no-PCOS, and IR-yes vs IR-no-EuHyperA. Compared to PCOS, EuHyperA had insignificantly lower glucose and insulin responses regardless of IR status. After steroidogenic ovarian stimulation (24 h-buserelin test), IR presence vs IR absence impacted on 4 curves in PCOS (significantly higher TT, borderline higher 17-OHP, significantly lower Δ4-ASD and DHEAS), and only one curve in EuHyperA (significantly higher TT). IR-no-EuHyperA had two curves significantly lower than IR-no-PCOS (Δ4-ASD and TT). Instead, IR-yes-EuHyperA had significantly lower Δ4-ASD, TT and 17-OHP curves, and significantly higher DHEAS curve vs IR-yes-PCOS. In conclusion, of 35 parameters (baseline, OGTT-related, buserelin-related), 28 (80%) were statistically similar in EuHyperA vs PCOS regardless of IR status. However, IR presence impacted on more parameters in PCOS than EuHyperA. Given the known ovary sparing by IR in PCOS, it appears that IR exacerbates androgen production of PCOS women more markedly than EuHyperA women.