Hyperandrogenic eumenorrheic NON-PCOS women versus women with PCOS after the GnRH-agonist stimulation test preceded by suppression of adrenal steroidogenesis with dexamethasone

Abstract

The subject of polycystic ovary syndrome (PCOS) has been extensively covered in the literature; however, there is a paucity of data regarding eumenorrheic women with hyperandrogenism and/or hyperandrogenemia without ultrasound evidence of PCO morphology (EuHyperA), and even less data on the comparison between PCOS and EuHyperA subjects. It has previously been shown that around half of PCOS women exhibit a hyper-response of serum 17-hydroxy-progesterone (17-OHP) to the stimulation by GnRH-agonists, also indicated as functional ovarian hyperandrogenism (FOH). Often, this stimulation test is preceded by suppression of the adrenal steroidogenesis with oral dexamethasone (Dex). FOH has been associated with an increase of the P450c17 activity in the ovaries driven by elevated insulin levels. Interestingly, treatment of women with PCOS with Dex suppression and GnRH-agonist stimulation (buserelin) highlighted the possible existence of two clusters of patients: hyper-responders (HR) and normal responders (NR).

In this retrospective study, we included 15 hyper-responders (HR) EuHyperA, 34 normal responders (NR) EuHyperA, 62 HR-PCOS and 45 NR-PCOS. The demographic characteristics, glucose-metabolism indices, and the hormonal response to Dex or buserelin were analyzed, with both intra-group and inter-group comparisons performed.

The rate of FOH was significantly greater in PCOS than EuHyperA women. Compared to HR-PCOS, HR-EuHyperA had [i.] significantly greater age at observation; [ii.] lower cortisol, 17-OHP, Δ4-androstenedione (Δ4-ASD), total testosterone (TT), LH, and buserelin-stimulated whole curve of dehydroepiandrosterone sulfate (DHEAS), 17-OHP, Δ4-ASD and TT. Compared to NR-PCOS, NR-EuHyperA had [i.] significantly greater FSH, and buserelin-stimulated whole curve of DHEAS; [ii.] significantly lower post-HD Dex Δ4-ASD, TT, buserelin-stimulated whole curve of 17-OHP, Δ4-ASD and TT. Compared to NR-PCOS, HR-PCOS had [i.] significantly greater body mass index (BMI), homeostasis model assessment for insulin resistance (HOMA-IR), cortisol, DHEAS, Δ4-ASD, TT, FT, FAI, E2, and insulin AUC_0-120min (area under the curve) at oral glucose tolerance test (OGTT); [ii] higher levels of post-LD and post-HD Dex 17-OHP, Δ4-ASD, TT, post-HD Dex DHEAS (with greater levels indicating weaker adrenal suppression), whole curve of DHEAS, 17-OHP, Δ4-ASD, TT and LH; [iii] significantly lower sex-hormone binding globulin (SHBG).

Even if most of the parameters evaluated were statistically similar in the two sets of comparisons, interesting differences were observed. Women with PCOS exhibit higher androgen levels at baseline, after adrenal suppression and at the buserelin test, further to a higher ovarian volume. Of note, the percentage of women with HOMA-IR≥2.5 and serum insulin levels were greater in PCOS group compared to EuHyperA women. Moreover, within women with PCOS, the HR subgroup has higher insulin levels compared to the NR subgroup, when OGTT is performed. The alteration of the glucose-insulin balance and elevation of circulating androgens were more pronounced in PCOS, thus indicating that [i.] metabolic alterations might be crucial in the onset of PCOS itself and, [ii] EuHyperA might represent a milder form of PCOS.