Insulin-Mediated Substrate Use in Women With Different Phenotypes of PCOS: the Role of Androgens

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

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 AUC0-120min (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.

IL-18BP Therapy Ameliorates Reproductive and Metabolic Phenotypes in a PCOS Mouse Model by Relieving Inflammation, Fibrosis and Endoplasmic Reticulum Stress

There is a chronic inflammation in PCOS patients, which is correlated with the pathogenesis of PCOS. IL-18 and IL-18BP are related with some inflammatory diseases, while less explored in PCOS. Whether IL-18BP could be a potential drug of PCOS remains unknown.IL-18 and testosterone levels were evaluated in serum of 10 non-PCOS control patients and 20 PCOS patients. Female C57/BL6 mice were gavaged with letrozole to induce PCOS mouse model and IL-18 level was evaluated in the serum of PCOS mouse model, and IL-18 is intraperitoneally injected in female mice, IL-18BP is intraperitoneally injected in the PCOS mice models. Then the body weights, estrous cycles, reproductive hormones and morphology of ovaries were analyzed. The level of ovarian chronic inflammation, fibrosis and endoplasmic reticulum (ER) stress are evaluated.IL-18 levels are increased in the serum of PCOS patients and PCOS mice models respectively. The serum DHEAS, iWAT weight and adipocyte size were increased in IL-18 group compared to the control group (P < 0.05). In the PCOS mouse model treated with IL-18BP, the body weight and serum LH/FSH ratio was decreased compared to the PCOS group (P < 0.05). The expression levels of inflammatory factors and fibrosis-related genes, the expression level of endoplasmic reticulum stress-related genes, and the ROS positive area of ovarian tissue was decreased (P < 0.05).IL-18 is involved in inducing PCOS phenotypes, while IL-18BP relieves PCOS phenotypes by alleviating ovarian chronic inflammation, fibrosis and ER stress in PCOS mice.

Gonadotropin upregulates intraovarian calpains-1 and -2 during ovarian follicular recruitment in the SD rat model

Calpain role has been shown in the cumulus cell-oocyte complexes and, corpus luteum. We investigated the association of calpains-1 and -2 in ovarian folliculogenesis using the Sprague-Dawley (SD) rat model and steroidogenesis in the human granulosa cells (hGCs). We induced PCOS in 42-day-old SD rats by letrozole oral gavage for 21 days. Premature ovarian failure (POF) was induced in 21-day-old SD rats by 4-vinylcyclohexene diepoxide (VCD). Ovulation and ovarian hyperstimulatory (OHS) syndrome were induced by pregnant mare gonadotropin (PMSG) + human chorionic gonadotropin (hCG) treatments in 21 days SD rats, respectively. Steroidogenesis is stimulated in human granulosa cells (hGCs) by forskolin and the response of 17-beta-estradiol (E2) on calpains expression was checked in hGCs. The protein expression by immunoblotting and activity by biochemical assay of calpains-1 and -2 showed an oscillating pattern in the ovarian cycle. PMSG-induced follicular recruitment showed upregulation of calpains-1 and -2, but with no change during ovarian function cessation (POF). Upregulated calpain-2 expression and calpain activity was found in the hCG +PMSG-induced ovulation. Letrozole-induced PCOS showed downregulation of calpain-1, but upregulation of calpain-2. PMSG+hCG-induced OHS led to the upregulation of calpain-1. Letrozole and metformin separately increased the expression level of calpains-1 and -2 in the hGCs during luteinization. In conclusion, the expression levels of calpains -1 and -2 are increased with ovarian follicular recruitment by PMSG and calpain-1 is decreased in the PCOS condition, and letrozole and metformin upregulate the expression of calpains-1 and -2 during luteinization in the hGCs possibly via E2 action.

Hyperandrogenism and Cardiometabolic Risk in Pre- and Postmenopausal Women-What Is the Evidence?

Hyperandrogenism in women, such as polycystic ovary syndrome, ovarian hyperthecosis, congenital adrenal hyperplasia, and androgen-secreting tumors, are all associated with increased prevalence of cardiovascular risk factors that include type 2 diabetes, hypertension, dyslipidemia, and metabolic syndrome. However, it is not clear whether this also implies enhanced risk of cardiovascular disease and mortality. Furthermore, the involvement of obesity and menopausal status for cardiometabolic risk in these women has not been elucidated. Based on the most recent systematic reviews and meta-analyses, this review summarizes the latest scientific evidence. To conclude, hyperandrogenism in premenopausal women is associated with enhanced prevalence of cardiovascular risk factors, as well as increased risk of cardiovascular disease and mortality, independently of body mass index. In contrast, elevated cardiovascular risk factors and increased risk of myocardial infarction and stroke in hyperandrogenic postmenopausal women are dependent on obesity. Furthermore, the overall risk of cardiovascular disease and coronary artery disease in hyperandrogenic postmenopausal women is similar to controls. The reason for a reduced cardiometabolic risk after menopause in hyperandrogenic women compared to nonhyperandrogenic women is not clear. It can be speculated that the difference in endocrine balance and metabolic status between women with and without hyperandrogenism might decrease after menopause because hyperandrogenism usually improves with age, whereas menopausal transition itself is associated with androgen dominance and abdominal obesity. Although we have gained increased knowledge about cardiometabolic risks in women with hyperandrogenism, it must be acknowledged that the quality of data is overall low. More research is needed, especially longer and larger follow-up studies in women with hyperandrogenism of different etiologies and phenotypes.

Treatment with Myo-Inositol Does Not Improve the Clinical Features in All PCOS Phenotypes

BACKGROUND

The aim of the present study is to investigate the effects produced by a treatment with myo-Inositol (myo-Ins) in women presenting polycystic ovary syndrome (PCOS) of different phenotypes.

METHODS

We performed a retrospective study to evaluate whether patients presenting different PCOS phenotypes, treated for 6 months with myo-Ins, might exhibit a differential response to the treatment. On this premise, we clustered women with PCOS phenotypes A, B, and C in the first study group (hyperandrogenic PCOS or H-PCOS), and women presenting PCOS phenotype D in a separate study group (non-hyperandrogenic PCOS or NH-PCOS) to evaluate if the presence of hyperandrogenism, shared by H-PCOS, might imply a metabolic/endocrine condition rather than a gynecological issue.

RESULTS

The administration of myo-Ins induced a significant improvement in metabolic and endocrine parameters in H-PCOS, while the effects on NH-PCOS were negligible. Additionally, myo-Ins treatment improved the endometrial thickness of H-PCOS.

CONCLUSIONS

Subjects selected for the study exhibited a differential response to myo-Ins therapy according to their PCOS phenotypes. The data suggest that the same treatment might not equally improve the parameters of the PCOS condition in each sub-group of patients. It is crucial to distinguish the various phenotypes to properly select the therapeutical approach.

A PCOS Paradox: Does Inositol Therapy Find a Rationale in All the Different Phenotypes?

A recent evaluation of the published data regarding the PCOS topic has highlighted a paradox in the definition of this condition. Even though the name of the syndrome refers to ovarian dysfunction, it seems that patients diagnosed with PCOS are more likely affected by an endocrine and metabolic issue. The term PCOS might not be appropriate to indicate the phenotypes described by the Rotterdam criteria, since the only phenotype with a gynecological issue alone is PCOS phenotype D. This novel perspective regarding how PCOS is currently defined leads the way to a reinterpretation of the entire pathological context and the treatment prescribed, such as inositols. A new point of view on the etiopathogenesis of the disease completely changes the current meaning of PCOS and consequently the therapeutic rationale evaluated to date.

Treatments targeting neuroendocrine dysfunction in polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age and is the leading cause of anovulatory subfertility. Increased gonadotrophin releasing hormone (GnRH) pulsatility in the hypothalamus results in preferential luteinizing hormone (LH) secretion from the pituitary gland, leading to ovarian hyperandrogenism and oligo/anovulation. The resultant hyperandrogenism reduces negative feedback from sex steroids such as oestradiol and progesterone to the hypothalamus, and thus perpetuates the increase in GnRH pulsatility. GnRH neurons do not have receptors for oestrogen, progesterone, or androgens, and thus the disrupted feedback is hypothesized to occur via upstream neurons. Likely candidates for these upstream regulators of GnRH neuronal pulsatility are Kisspeptin, Neurokinin B (NKB), and Dynorphin neurons (termed KNDy neurons). Growing insight into the neuroendocrine dysfunction underpinning the heightened GnRH pulsatility seen in PCOS has led to research on the use of pharmaceutical agents that specifically target the activity of these KNDy neurons to attenuate symptoms of PCOS. This review aims to highlight the neuroendocrine abnormalities that lead to increased GnRH pulsatility in PCOS, and outline data on recent therapeutic advancements that could potentially be used to treat PCOS. Emerging evidence has investigated the use of neurokinin 3 receptor (NK3R) antagonists as a method of reducing GnRH pulsatility and alleviating features of PCOS such as hyperandrogenism. We also consider other potential mechanisms by which increased GnRH pulsatility is controlled, which could form the basis of future avenues of research.

Clinical Value of Serum Levels of 11-Oxygenated Metabolites of Testosterone in Women With Polycystic Ovary Syndrome

CONTEXT

Recent data suggested that 11-oxygenated androgens may be the preponderant circulating androgens in women with PCOS. However, the pathophysiological significance of these hormones remains unclear.

OBJECTIVE

The aim of this study was to evaluate the relationships between serum 11-OH testosterone (11-OHT) and 11-keto testosterone (11-KetoT) and clinical and biochemical hyperandrogenism, as well as the metabolic parameters, in women with PCOS.

METHODS

The main classic and 11-oxygenated androgens were measured by LC-MS/MS and direct equilibrium dialysis in 123 women with PCOS, diagnosed according to the Rotterdam criteria, and 38 healthy controls. Insulin sensitivity was assessed by hyperinsulinemic euglycemic clamp.

RESULTS

Serum 11-oxygenated androgens were higher in women with PCOS than in controls. Elevated levels of 11-OHT and 11-KetoT were found in 28.5% and 30.1% of PCOS women, respectively, whereas free testosterone (FT) was increased in 61.0% of them. Serum 11-oxygenated androgens showed a limited performance in recognizing women with classically defined hyperandrogenism. Unlike FT, 11-oxygenated androgens did not show significant relationships with anthropometric and metabolic parameters, except for a direct association with insulin sensitivity. In multivariable analysis, 11-OHT and 11-KetoT, directly, and FT, inversely, remained significant independent predictors of insulin sensitivity.

CONCLUSIONS

Serum levels of 11-oxygenated androgens are higher in women with PCOS than in controls. However, these hormones show a poor performance in recognizing women with hyperandrogenism, as currently defined. The relationships of these androgens with insulin sensitivity strongly differ from that of FT, suggesting a different role of classic and 11-oxygenated androgens in the pathophysiology of PCOS.