New Perspectives on the Pathogenesis of PCOS: Neuroendocrine Origins

Adipokine levels and carbohydrate metabolism in patients diagnosed de novo with polycystic ovary syndrome

INTRODUCTION

Central obesity appears to play a major role in the pathogenesis of metabolic disorders in polycystic ovary syndrome. Insulin resistance and carbohydrate disorders are associated with dysfunctional secretion of various adipokines by the adipose tissue.

OBJECTIVES

This study aimed to evaluate leptin, apelin, and visfatin against a background of carbohydrate metabolism parameters in patients diagnosed de novo with polycystic ovary syndrome (PCOS).

MATERIAL AND METHODS

The study group consisted of 40 patients with PCOS (mean age, 29 years) diagnosed in accordance with the American Society for Reproductive Medicine criteria from 2003. The control group consisted of 37 clinically healthy women (mean age, 26 years). All controls had regular menses and no clinical or biochemical signs of hyperandrogenism. Concentrations of leptin, apelin, visfatin, and insulin were measured by immunoenzymatic methods. Glucose concentrations were determined using spectrophotometry.

RESULTS

Significantly higher concentrations of leptin, insulin, homeostatic model assessment for insulin resistance (HOMA-IR) index, and the immunoreactive insulin (IRI)/glucose index were found in the PCOS group than in the control group. Notably, the concentration of apelin was over five times lower in the PCOS group than in the control group. In patients with PCOS, a positive correlation was found between the concentrations of insulin and leptin and concentrations of leptin and IRI/glucose. Patients of the PCOS group with body mass index (BMI) ≥  25 had significantly higher values of leptin, insulin, HOMA-IR index, and IRI/glucose index than patients of the PCOS group with normal BMI. In the PCOS group, a positive correlation was found between BMI and leptin concentration (r = 0.7176; p < 0.0001) and carbohydrate metabolism, such as insulin (r = 0.5524; p = 0.0003), glucose (r = 0.3843; p = 0.0157), HOMA-IR (r = 0.5895; p < 0.0001), and IRI/glucose (r = 0.3872; p = 0.0163). These findings were not observed in the control group.

CONCLUSIONS

(1) Increased leptin concentration observed in women diagnosed de novo with PCOS as well as positive correlations between leptin and HOMA-IR, and IRI/glucose and BMI may indicate a potential role of leptin in the reduction of tissue sensitivity to insulin. (2) Significantly lower apelin concentration in the PCOS group (>5 fold) than in the control group, associated with a concomitant increase in leptin, may also contribute to carbohydrate metabolism disorders occurring in the course of PCOS.

The Need to Reassess the Diagnosis of Polycystic Ovary Syndrome (PCOS): A Review of Diagnostic Recommendations from the International Evidence-Based Guideline for the Assessment and Management of PCOS

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that is associated with negative metabolic, reproductive, endocrine, and psychological consequences among women of reproductive age. The diagnosis of PCOS remains challenging due to limited and conflicting evidence regarding definitions for each of the diagnostic features. This review of the recommended PCOS assessment criteria from the international evidence-based guideline highlights the crucial need to reassess, redefine, and optimize the diagnosis of PCOS. Notably, normal values and cut-offs need to be defined for each diagnostic feature across the lifespan and diverse ethnic groups. Understanding how these features cluster together and relate to short- and long-term health outcomes in PCOS is also vital. Ultimately, greater knowledge of the natural history of PCOS is needed through well-characterized, community-based longitudinal studies, which will inform future PCOS diagnosis guidelines and optimize women's health in reproductive life.

Constitutive expression of Steroidogenic factor-1 (NR5A1) disrupts ovarian functions, fertility, and metabolic homeostasis in female mice

Steroid hormones regulate various aspects of physiology, from reproductive functions to metabolic homeostasis. Steroidogenic factor-1 (NR5A1) plays a central role in the development of steroidogenic tissues and their ability to produce steroid hormones. Inactivation of Nr5a1 in the mouse results in a complete gonadal and adrenal agenesis, absence of gonadotropes in the pituitary and impaired development of ventromedial hypothalamus, which controls glucose and energy metabolism. In this study, we set out to examine the consequences of NR5A1 overexpression (NR5A1+) in the NR5A1-positive cell populations in female mice. Ovaries of NR5A1+ females presented defects such as multi-oocyte follicles and an accumulation of corpora lutea. These females were hyperandrogenic, had irregular estrous cycles with persistent metestrus and became prematurely infertile. Furthermore, the decline in fertility coincided with weight gain, increased adiposity, hypertriglyceridemia, hyperinsulinemia, and impaired glucose tolerance, indicating defects in metabolic functions. In summary, excess NR5A1 expression causes hyperandrogenism, disruption of ovarian functions, premature infertility, and disorders of metabolic homeostasis. This NR5A1 overexpression mouse provides a novel model for studying not only the molecular actions of NR5A1, but also the crosstalk between endocrine, reproductive, and metabolic systems.

Morphological evidence indicates a role for microglia in shaping the PCOS-like brain

Although polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility worldwide, the aetiology of the disorder remains poorly defined. Animal-based evidence highlights the brain as a prime suspect in both the development and maintenance of PCOS. Prenatally androgenised (PNA) models of PCOS exhibit excessive GABAergic wiring associated with PCOS-like reproductive deficits in adulthood, with aberrant brain wiring detected as early as postnatal day (P) 25, prior to disease onset, in the PNA mouse. The mechanisms underlying this aberrant brain wiring remain unknown. Microglia, the immune cells of the brain, are regulators of neuronal wiring across development, mediating both the formation and removal of neuronal inputs. Here, we tested the hypothesis that microglia play a role in the excessive GABAergic wiring that leads to PCOS-like features in the PNA brain. Using specific immunolabelling, microglia number and morphology associated with activation states were analysed in PNA and vehicle-treated controls across developmental timepoints, including embryonic day 17.5, P0, P25 and P60 (n = 7-14 per group), and in two regions of the hypothalamus implicated in fertility regulation. At P0, fewer amoeboid microglia were observed in the rostral preoptic area (rPOA) of PNA mice. However, the greatest changes were observed at P25, with PNA mice exhibiting fewer total microglia, and specifically fewer "sculpting" microglia, in the rPOA. Based on these findings, we assessed microglia-mediated refinement of GABAergic synaptic terminals at two developmental stages of peak synaptic refinement: P7 and P15 (n = 7 per group). PNA mice showed a reduction in the uptake of GABAergic synaptic material at P15. These findings reveal time-specific changes in the microglia population and refinement of GABAergic inputs in a mouse model of PCOS driven by prenatal androgen excess and suggest a role for microglia in shaping the atypical brain wiring associated with the development of PCOS features.

Obesity, but not hyperandrogenism or insulin resistance, predicts skeletal muscle mass in reproductive-aged women with polycystic ovary syndrome: A systematic review and meta-analysis of 45 observational studies

Women with polycystic ovary syndrome (PCOS) exhibit reduced muscle insulin-mediated glucose uptake, potentially attributed to altered muscle mass; however, this is inconclusive. Altered muscle mass may aggravate PCOS complications. Our systematic review and meta-analysis evaluated whether PCOS alters muscle mass and function. Databases (MEDLINE, Web of Science, Scopus) were searched through September 2, 2020, for studies documenting skeletal muscle mass (lean tissue mass) and function (strength) in PCOS and control groups. The primary outcome was total lean body mass (LBM) or fat-free mass (FFM). Data were pooled by random-effects models and expressed as mean differences and 95% confidence intervals. Forty-five studies (n = 3676 participants) were eligible. Women with PCOS had increased total (0.83 [0.08,1.58] kg; p = 0.03; I²  = 72.0%) yet comparable trunk (0.84 [-0.37,2.05] kg; p = 0.15; I²  = 73.0%) LBM or FFM versus controls. Results of meta-regression analyses showed no associations between mean differences between groups in total testosterone or homeostatic model assessment of insulin resistance and total or trunk LBM or FFM (All: p ≥ 0.75). Mean differences in body mass index (BMI) were associated with total (0.65 [0.23,1.06] kg; p < 0.01; I²  = 56.9%) and trunk (0.56 [0.11,1.01] kg; p = 0.02; I²  = 42.8%) LBM or FFM. The PCOS subgroup with BMI ≥ 25 kg/m² had greater total LBM or FFM versus controls (1.58 [0.82,2.34] kg; p < 0.01; I²  = 64.0%) unlike the PCOS subgroup with BMI < 25 kg/m² (-0.45 [-1.94,1.05] kg; p = 0.53; I²  = 69.5%). Appendicular lean mass and muscle strength data were contradictory and described narratively, as meta-analyses were impossible. Women with PCOS have higher total and trunk lean tissue mass attributed to overweight/obesity, unlike hyperandrogenism or insulin resistance.

Thyroid, Adrenal, PRL Impairments and Ovarian Function

Endocrine axes (prolactin, thyroid and adrenal axes) directly and indirectly modulate and drive human female central functions, mainly behavior and reproduction. Though having distinct abilities, they greatly act both at peripheral as well as at neuroendocrine levels, so as to participate in the control of reproduction. Any event that changes these balanced activities produces specific peripheral signals that induce abnormal functions centrally, thus triggering menstrual disorders such as oligomenorrhea or amenorrhea. It is clear that the knowledge of the relationships that exist between the different endocrine axes becomes essential for the choice of therapeutical approach. This review aims to focus on the main aspects of the physiopathology of the endocrine diseases that might be at the basis of that interference with female reproductive capacity.

The relationships of sex hormone-binding globulin, total testosterone, androstenedione and free testosterone with metabolic and reproductive features of polycystic ovary syndrome

Objective

A recent Mendelian randomization study has suggested a causal role for sex hormone‐binding globulin (SHBG), total testosterone and free testosterone in the pathogenesis of polycystic ovary syndrome (PCOS). The aim of this study was to assess the relationships of SHBG, androstenedione, total and free testosterone with the individual metabolic and reproductive features of PCOS.

Design

Cross‐sectional data in PCOS patients (n=96) prospectively collected in a secondary/tertiary clinic for menstrual cycle disorders.

Methods

Multivariable regression analyses were conducted to study the associations between SHBG, androstenedione, total and free testosterone with metabolic (BMI, waist circumference, systolic and diastolic blood pressure, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and homeostatic model assessment for insulin resistance [HOMA2‐IR]) and reproductive features (menstrual cycle length, antral follicle count, anti‐Müllerian hormone, luteinizing hormone, follicle‐stimulating hormone and Ferriman‐Gallwey score) of PCOS.

Results

Serum SHBG and free testosterone, but not total testosterone or androstenedione, were significantly associated with BMI, waist circumference, serum triglycerides, HDL cholesterol, LDL cholesterol and HOMA2‐IR. The strength of the associations with serum lipids was reduced after adjustment for BMI, but not for HOMA2‐IR. Total testosterone was significantly associated with antral follicle count. SHBG, total testosterone and androstenedione were significantly associated with serum AMH. Only the strength of the association for SHBG was reduced after adjustment for BMI.

Conclusions

Serum SHBG is associated with primarily metabolic features, whereas total testosterone and androstenedione are associated with reproductive features of PCOS. These results suggest a differential underlying pathophysiology for the metabolic and reproductive features of PCOS.

Endometriosis and polycystic ovary syndrome are diametric disorders

Evolutionary and comparative approaches can yield novel insights into human adaptation and disease. Endometriosis and polycystic ovary syndrome (PCOS) each affect up to 10% of women and significantly reduce the health, fertility, and quality of life of those affected. PCOS and endometriosis have yet to be considered as related to one another, although both conditions involve alterations to prenatal testosterone levels and atypical functioning of the hypothalamic-pituitary-gonadal (HPG) axis. Here, we propose and evaluate the novel hypothesis that endometriosis and PCOS represent extreme and diametric (opposite) outcomes of variation in HPG axis development and activity, with endometriosis mediated in notable part by low prenatal and postnatal testosterone, while PCOS is mediated by high prenatal testosterone. This diametric disorder hypothesis predicts that, for characteristics shaped by the HPG axis, including hormonal profiles, reproductive physiology, life-history traits, and body morphology, women with PCOS and women with endometriosis will manifest opposite phenotypes. To evaluate these predictions, we review and synthesize existing evidence from developmental biology, endocrinology, physiology, life history, and epidemiology. The hypothesis of diametric phenotypes between endometriosis and PCOS is strongly supported across these diverse fields of research. Furthermore, the contrasts between endometriosis and PCOS in humans parallel differences among nonhuman animals in effects of low versus high prenatal testosterone on female reproductive traits. These findings suggest that PCOS and endometriosis represent maladaptive extremes of both female life-history variation and expression of sexually dimorphic female reproductive traits. The diametric disorder hypothesis for endometriosis and PCOS provides novel, unifying, proximate, and evolutionary explanations for endometriosis risk, synthesizes diverse lines of research concerning the two most common female reproductive disorders, and generates future avenues of research for improving the quality of life and health of women.

Polycystic Ovary Syndrome Can Lead to Neurocognitive Changes in Female Rats Treated with Letrozole

Background: Polycystic ovary syndrome (PCOS) is a common endocrine disorder in premenopausal women. Brain functions may be affected in PCOS, and studies reported that PCOS patients are at greater risk for developing mental health conditions, including anxiety or depression. Objectives: This study was designed to evaluate the neurocognitive changes in letrozole-induced PCOS model. Methods: Twenty female Wistar rats (eight-week-old; 160 ± 10 g) were divided into two groups. Group one received vehicle only (carboxymethyl cellulose, orally) once daily, and group two received letrozole (1 mg/kg, orally) once daily. Drugs or vehicles were administered for 21 days. Afterward, behavioral tests, including forced swimming test, open field test, and Y-maze alteration task, were performed. Ovaries were removed after behavioral tests and assessed histologically to confirm the induction of PCOS. Results: Animals with PCOS developed depressive-like behaviors compared with control in forced swimming test (P < 0.001). Anxiety-like behaviors were detected in letrozole-induced PCOS group (P < 0.05). Moreover, animals with PCOS exhibited memory impairment in comparison to normal animals in Y-maze memory assessment (P < 0.05). Conclusions: Rats with PCOS showed a neurocognitive decline in the model of letrozole administration. Future studies should be conducted to clarify the exact mechanisms of these changes and possible approaches to restore them.

Neurokinin 3 Receptor Antagonism Ameliorates Key Metabolic Features in a Hyperandrogenic PCOS Mouse Model

Polycystic ovary syndrome (PCOS) is a prevalent endocrine condition characterized by a range of endocrine, reproductive, and metabolic abnormalities. At present, management of women with PCOS is suboptimal as treatment is only symptomatic. Clinical and experimental advances in our understanding of PCOS etiology support a pivotal role for androgen neuroendocrine actions in PCOS pathogenesis. Hyperandrogenism is a key PCOS trait and androgen actions play a role in regulating the kisspeptin-/neurokinin B-/dynorphin (KNDy) system. This study aimed to investigate if targeted antagonism of neurokinin B signaling through the neurokinin 3 receptor (NK3R) would reverse PCOS traits in a dihydrotestosterone (DHT)-induced mouse model of PCOS. After 3 months, DHT exposure induced key reproductive PCOS traits of cycle irregularity and ovulatory dysfunction, and PCOS-like metabolic traits including increased body weight; white and brown fat pad weights; fasting serum triglyceride and glucose levels, and blood glucose incremental area under the curve. Treatment with a NK3R antagonist (MLE4901) did not impact the observed reproductive defects. In contrast, following NK3R antagonist treatment, PCOS-like females displayed decreased total body weight, adiposity, and adipocyte hypertrophy, but increased respiratory exchange ratio, suggesting NK3R antagonism altered the metabolic status of the PCOS-like females. NK3R antagonism did not improve circulating serum triglyceride or fasted glucose levels. Collectively, these findings demonstrate that NK3R antagonism may be beneficial in the treatment of adverse metabolic features associated with PCOS and support neuroendocrine targeting in the development of novel therapeutic strategies for PCOS.

Polycystic Ovary Syndrome and Fibrocystic Breast Disease: An Updated Review

Polycystic ovary syndrome (PCOS) is the most common hormonal disorder in women of reproductive age. There is no clear association between PCOS and benign breast disease (BBD). The latter is a frequent benign disorder, affecting women between 20 and 50 years of age. To date, the classification remains controversial, and the risk of developing breast cancer that is associated with these changes is different depending on the histopathological findings. The most frequent changes are breast cysts, which are noted in up to 50% of patients older than 30 years of age. This up-to-date review presents the relationship between PCOS and BBD. In conclusion, there is no clear association between benign breast disease and PCOS. Further studies on a large population with prospectively collected data using updated PCOS criteria are necessary.

Ovarian cysts disappear after 14-day oral regimen of Korean red ginseng extract in letrozole-induced polycystic ovarian syndrome

Objective

Hormonal and inflammatory mechanisms are involved in the pathogenesis of polycystic ovarian syndrome (PCOS), which is a prevalent metabolic disorder among women of reproductive age. We aimed to evaluate the comparative efficiency of short-term oral administration of Korean red ginseng extract (KRGE) and the standard treatment on PCOS by focusing on the histopathological parameters and serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and nuclear factor kappa B (NF-κB).

Methods

A PCOS rat model was established by oral gavage of letrozole (1 mg/kg) for 21 days. The serum levels of LH, FSH, testosterone, and NF-κB were measured, and the morphological features and differences of the ovaries were examined in each group using a light microscope before and after 14 days of treatment with oral regimens—KRGE, oral contraceptives (OCPs), KRGE+OCPs, and carboxymethyl cellulose (CMC).

Results

OCPs alone could not normalize the mean ovarian weights of PCOS rats despite the 14-day oral regimen, but they were more effective in reducing the number and size of cysts compared to others. KRGE alone and in combination with OCPs was effective in normalizing abnormal ovarian weights, decreasing LH serum levels, and dissipating the ovarian cysts in PCOS rats. However, when combined with the standard regimen, KRGE showed additional therapeutic effects by efficiently reducing serum testosterone and NF-κB levels.

Conclusion

Our necropsy and histopathological evidence suggests the efficacy of KRGE as a novel integrative medicine against abnormal multiple follicular cysts. However, antiandrogenic and anti-inflammatory effects were only seen in animals that were administered a combination of KRGE and the standard regimen.

Polycystic ovary syndrome is transmitted via a transgenerational epigenetic process

Polycystic ovary syndrome (PCOS) is the most common reproductive and metabolic disorder affecting women of reproductive age. PCOS has a strong heritable component, but its pathogenesis has been unclear. Here, we performed RNA sequencing and genome-wide DNA methylation profiling of ovarian tissue from control and third-generation PCOS-like mice. We found that DNA hypomethylation regulates key genes associated with PCOS and that several of the differentially methylated genes are also altered in blood samples from women with PCOS compared with healthy controls. Based on this insight, we treated the PCOS mouse model with the methyl group donor S-adenosylmethionine and found that it corrected their transcriptomic, neuroendocrine, and metabolic defects. These findings show that the transmission of PCOS traits to future generations occurs via an altered landscape of DNA methylation and propose methylome markers as a possible diagnostic landmark for the condition, while also identifying potential candidates for epigenetic-based therapy.

Hyperandrogenic Anovulation: Differential Diagnosis and Evaluation

Hyperandrogenic anovulation refers to the constellation of disorders that present in women with irregular menses, hirsutism and/or acne across the lifespan. Understanding the clinical signs and symptoms of each diagnosis in the differential and laboratory testing to confirm or exclude a diagnosis allows a clinician to appropriately counsel and treat the patient.

Paeoniflorin attenuates DHEA-induced polycystic ovary syndrome via inactivation of TGF-β1/Smads signaling pathway in vivo

Polycystic ovarian syndrome (PCOS) is one of the most common reproductive endocrine disorders which are involved in complicated and unknown pathogenic mechanisms. Paeoniflorin (PAE) plays a significant anti-fibrotic role according to previous studies. The aim of the present study was to investigate the effect of PAE on ovarian fibrosis and its underlying mechanism in PCOS development. An animal model of PCOS was established by subcutaneous injection of 60mg/kg/d dehydroepiandrosterone (DHEA) for 35 consecutive days. Rats in PAE-L, PAE-M and PAE-H groups were administrated by gavage with PAE (20, 40, 80 mg/kg/d) for 4 weeks. Our results indicated that DHEA-induced PCOS rats showed similar phenotypes with PCOS patients. PAE could significantly block the DHEA-induced decline of ovary weight and organ coefficient, shorten the prolonged diestrus period, and regulate the irregular estrous cycle of PCOS rats. Moreover, PAE regulated reproductive hormone levels and improved ovarian fibrosis induced by DHEA. PAE treatment could also reduce the expression levels of TGF-β1 and Smad3, and increase the expression levels of Smad7 and MMP2. In conclusion, PAE significantly attenuated the ovarian fibrosis in PCOS, which could be mediated by TGF-β1/Smads signaling pathway. Herein, PAE can be used for the treatment of ovarian fibrosis in PCOS progression.

Improving the sexual activity and reproduction of female zebrafish with high testosterone levels

High levels of testosterone cause clinical symptoms in female reproduction and possibly, alterations in sexuality. Yet, the underlying mechanisms remain to be examined. Here, we report a study that investigates the effects of testosterone in follicle development and sexual mating using zebrafish models. We developed an acute zebrafish model with high testosterone levels by exposing young female zebrafish to testosterone dissolved in swimming water. After given a high concentration of testosterone treatment (e.g., 100 ng/ml), the fish showed hallmark pathological symptoms similar to those displayed in patients with polycystic ovary syndrome (PCOS), such as follicular growth-arrest, rare ovulation, ovary enlargement, decrease in reproduction, and down regulation of the expression of some PCOS susceptible genes, such as Tox3. These fish are referred to as the PCOS fish. By monitoring mating-like swimming behaviors, we measured the sexual activity of PCOS zebrafish. In general, the PCOS fish showed no desire to interact with males. As a consequence, their mating rate was decreased as compared to control animals. The sexuality levels of PCOS fish, however, could be improved after short periods of rearing in conditions that lack of males. After only 3 days of rearing alone, the PCOS fish showed an increase in sexuality levels and displayed characteristic swimming patterns for mating. After 30 days of separation from males, not only the sexual activity, but also the mating rate was improved in the PCOS fish. Together, the data suggests that zebrafish can serve as a new type of research model to further develop strategies for the treatment of reproductive disorders, such as those related to PCOS.

Insulin resistance and PCOS: chicken or egg?

PCOS is a common and heterogeneous endocrine disorder in women of reproductive age, frequently associated with metabolic abnormalities. It was estimated that about 75% of these subjects have an impairment of insulin action, as measured by gold standard methods. While the relationship between insulin resistance and PCOS is consistently shown by a number of studies, the mechanisms underlying its primary origin still remains an unsolved issue. Insulin resistance and the associated hyperinsulinemia can induce both the endocrine and reproductive traits of PCOS. However, androgen excess, in turn, can impair insulin action, directly and/or through several changes occurring in different tissues. Body fat excess, which is another common feature in these women, can contribute to worsening the whole picture. Nevertheless, insulin resistance may also be found in many normal-weight individuals. Endocrine and metabolic abnormalities can develop in different moments, and probably there is fetal programming of these alterations. However, a number of vicious circles, with bidirectional relationships between androgen excess and insulin resistance, and with the contribution of several other factors, make it extremely difficult to understand where this process really originates. This review summarizes available evidence on this topic, in order to better understand the complex relationships linking hyperandrogenism and impaired insulin action in women with PCOS.

Polycystic Ovary Syndrome and Brain: An Update on Structural and Functional Studies

CONTEXT

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of women in reproductive age and is associated with reproductive, endocrine, metabolic, cardiovascular, and psychological outcomes. All these disorders are thought to be affected by central mechanisms which could be a major contributor in pathogenesis of PCOS.

EVIDENCE ACQUISITION

This mini-review discusses the relevance of central nervous system imaging modalities in understanding the neuroendocrine origins of PCOS as well as their relevance to understanding its comorbidities.

EVIDENCE SYNTHESIS

Current data suggest that central nervous system plays a key role in development of PCOS. Decreased global and regional brain volumes and altered white matter microstructure in women with PCOS is shown by structural imaging modalities. Functional studies show diminished reward response in corticolimbic areas, brain glucose hypometabolism, and greater opioid receptor availability in reward-related regions in insulin-resistant patients with PCOS. These structural and functional disturbances are associated with nonhomeostatic eating, diminished appetitive responses, as well as cognitive dysfunction and mood disorders in women with PCOS.

CONCLUSION

Structural and functional brain imaging is an emerging modality in understanding pathophysiology of metabolic disorders such as diabetes and obesity as well as PCOS. Neuroimaging can help researchers and clinicians for better understanding the pathophysiology of PCOS and related comorbidities as well as better phenotyping PCOS.

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.

Administration of a VIP-antagonist in vivo modifies ovarian hormone secretion in a rat model with polycystic ovary syndrome

AIMS

In the cyclic rat in estrus, the vasoactive intestinal peptide (VIP) has an impact on ovarian function, which depends on the endocrine status of the animal. In this work, we aimed to clarify the participation of VIP in the pathophysiological condition of polycystic ovary syndrome (PCOS) using a model of PCOS induced by estradiol valerate (EV-PCOS) in rats.

MAIN METHODS

In the cyclic rat in estrus and in the EV-PCOS model, we analyzed the acute effects of blocking VIP receptors with the use of an antagonist (Ant-VIP) injected into the left or right ovarian bursa on the steroidogenic response and ovarian catecholamine levels.

KEY FINDINGS

In the cyclic animal in estrus, the treatment with Ant-VIP in the left ovarian bursa resulted in a reduction in testosterone serum levels and in ovarian levels of dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC), without changes in 4-hydroxy-3-methoxyphenyl (MHPG) and norepinephrine (NE). When the treatment was applied on the right side, only MHPG levels increased. In the EV-PCOS model, the treatment with Ant-VIP in the left ovarian bursa increased testosterone, estradiol, MHPG, and NE levels. When the treatment was performed on the right side, progesterone levels decreased and estradiol increased, without changes in ovarian catecholamines.

SIGNIFICANCE

The binding of VIP to its receptors differentially regulates steroidogenesis in the cyclic animal in estrus and in the EV-PCOS model. The blocking of VIP signaling produces changes in ovarian catecholamines.

Polycystic Ovary Syndrome: A Brain Disorder Characterized by Eating Problems Originating during Puberty and Adolescence

Polycystic ovary syndrome (PCOS) is an endocrine condition associated with reproductive and psychiatric disorders, and with obesity. Eating disorders, such as bulimia and recurrent dieting, are also linked to PCOS. They can lead to the epigenetic dysregulation of the hypothalamic-pituitary-gonadal (HPG) axis, thereby impacting on ovarian folliculogenesis. We postulate that PCOS is induced by psychological distress and episodes of overeating and/or dieting during puberty and adolescence, when body dissatisfaction and emotional distress are often present. We propose that upregulated activation of the central HPG axis during this period can be epigenetically altered by psychological stressors and by bulimia/recurrent dieting, which are common during adolescence and which can lead to PCOS. This hypothesis is based on events that occur during a largely neglected stage of female reproductive development. To date, most research into the origins of PCOS has focused on the prenatal induction of this disorder, particularly in utero androgenization and the role of anti-Müllerian hormone. Establishing causality in our peripubertal model requires prospective cohort studies from infancy. Mechanistic studies should consider the role of the gut microbiota in addition to the epigenetic regulation of (neuro) hormones. Finally, clinicians should consider the importance of underlying chronic psychological distress and eating disorders in PCOS.

MiRNAs expression profiling of rat ovaries displaying PCOS with insulin resistance

Purpose

The present study established microRNA (miRNA) expression profiles for rat ovaries displaying polycystic ovary syndrome (PCOS) with insulin resistance and explored the underlying biological functions of differentially expressed miRNAs.

Methods

A PCOS with insulin resistance rat model was created by administering letrozole and a high-fat diet. Total RNA was extracted from the ovaries of PCOS with insulin resistance rats and normal rats. Three ovaries from each group were used to identify differentially expressed miRNAs by deep sequencing. A hierarchical clustering heatmap and volcano plot were used to display the pattern of differentially expressed miRNAs. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to explore the potential target genes of the differentially expressed miRNAs and identify their putative biological function. Nine of the differentially expressed miRNAs were selected for validation by Real-time Quantitative PCR (qRT-PCR).

Results

A total of 58 differentially expressed miRNAs were identified in the rat ovaries exhibiting PCOS with insulin resistance compared with control ovaries, including 23 miRNAs that were upregulated and 35 miRNAs that were downregulated. GO and KEGG pathway analyses revealed that the predicted target genes were related to metabolic processes, cellular processes, and metabolic pathways. Furthermore, qRT-PCR confirmed that miR-3585-5p and miR-30-5p were significantly upregulated and miR-146-5p was downregulated in the ovaries of PCOS with insulin resistance rats compared with the controls.

Conclusion

These results indicate that differentially expressed miRNAs in rat ovaries may be involved in the pathophysiology of insulin resistance in PCOS. Our study may be beneficial in establishing miRNAs as novel diagnostic and therapeutic biomarkers for insulin resistance in PCOS.

Anogenital distance and anti-Müllerian hormone combined improves the diagnosis of polycystic ovary syndrome

The objective of this study was to assess the accuracy of the combination of anogenital distance (AGD) and anti-Müllerian hormone (AMH) in the diagnosis of polycystic ovary syndrome (PCOS). The study included women diagnosed with PCOS and a control group who attended the Clinical University Hospital 'Virgen de la Arrixaca' in Murcia (Spain). Serum concentrations of AMH were measured and two AGD measurements were obtained: (i) from the anterior clitoral surface to the upper verge of the anus (AGD_AC); and (ii) from the posterior fourchette to the upper verge of the anus (AGD_AF). Data were assessed by receiver operator characteristic (ROC) curves. Women with PCOS (n = 126) had significantly larger AGD_AC (80.5 ± 11.3 versus 76.0 ± 10.4 mm; p < 0.001) and higher AMH (7.2 ± 4.7 versus 3.1 ± 2.2; p < 0.001) compared to control women (n = 159). Women with serum AMH above 3.8 ng/mL (clinical cut-off used in PCOS) were 9.1 times more likely to have PCOS (95% CI: 5.1-16.2). The area under the ROC curve of combined model of AMH and AGD_AC was 0.87 (95% CI: 0.83-0.91). The combined model for predicting PCOS based on AMH and AGD_AC has better diagnostic accuracy than that of AMH or AGD_AC alone. This model could be useful for clinicians and improve diagnosis and clinical management of these women.

Animal Models to Understand the Etiology and Pathophysiology of Polycystic Ovary Syndrome

More than 1 out of 10 women worldwide are diagnosed with polycystic ovary syndrome (PCOS), the leading cause of female reproductive and metabolic dysfunction. Despite its high prevalence, PCOS and its accompanying morbidities are likely underdiagnosed, averaging > 2 years and 3 physicians before women are diagnosed. Although it has been intensively researched, the underlying cause(s) of PCOS have yet to be defined. In order to understand PCOS pathophysiology, its developmental origins, and how to predict and prevent PCOS onset, there is an urgent need for safe and effective markers and treatments. In this review, we detail which animal models are more suitable for contributing to our understanding of the etiology and pathophysiology of PCOS. We summarize and highlight advantages and limitations of hormonal or genetic manipulation of animal models, as well as of naturally occurring PCOS-like females.

Androgen Action in Adipose Tissue and the Brain are Key Mediators in the Development of PCOS Traits in a Mouse Model

Polycystic ovary syndrome (PCOS) is a complex disorder characterized by endocrine, reproductive, and metabolic abnormalities. Despite PCOS being the most common endocrinopathy affecting women of reproductive age, the etiology of PCOS is poorly understood, so there is no cure and symptomatic treatment is suboptimal. Hyperandrogenism is the most consistent feature observed in PCOS patients, and recently aberrant neuroendocrine signaling and adipose tissue function have been proposed as playing a role in the development of PCOS. To investigate the role of adipose tissue and the brain as key sites for androgen receptor (AR)-mediated development of PCOS, we combined a white and brown adipose and brain-specific AR knockout (AdBARKO) mouse model with a dihydrotestosterone (DHT)-induced mouse model of PCOS. As expected, in wildtype (WT) control females, DHT exposure induced the reproductive PCOS traits of cycle irregularity, ovulatory dysfunction, and reduced follicle health, whereas in AdBARKO females, DHT did not produce the reproductive features of PCOS. The metabolic PCOS characteristics of increased adiposity, adipocyte hypertrophy, and hepatic steatosis induced by DHT in WT females were not evident in DHT-treated AdBARKO females, which displayed normal white adipose tissue weight and no adipocyte hypertrophy or liver steatosis. Dihydrotestosterone treatment induced increased fasting glucose levels in both WT and AdBARKO females. These findings demonstrate that adipose tissue and the brain are key loci of androgen-mediated actions involved in the developmental origins of PCOS. These data support targeting adipocyte and neuroendocrine AR-driven pathways in the future development of novel therapeutic strategies for PCOS.

Le syndrome des ovaires polykystiques : quelles nouveautés en 2019 ?

PolyCystic Ovary Syndrome (PCOS) is the first endocrinopathy of women of child-bearing age and the leading cause of anovulatory infertility. The pathophysiology of this syndrome is complex and involves genetic traits highlighted by GWAS and epigenetic traits with DNA methylation modifications. Initially described as an ovarian disease, works carried out over recent years were turned towards neuroendocrine disorder involving GABAergic pathways, KNDy neurons and a possible role of prenatal androgen exposure determined by animal models. Clinically, PCOS leads to many complications including psychological and emotional disorders demonstrated in large populations of PCOS women. © 2019 Published by Elsevier Masson SAS. All rights reserved. Cet article fait partie du numéro supplément Les Must de l'Endocrinologie 2019 réalisé avec le soutien institutionnel de Ipsen-Pharma.

Gut microbiota dysbiosis in polycystic ovary syndrome: association with obesity - a preliminary report

The objective was to explore if and how the microbiota changed in polycystic ovary syndrome (PCOS) women compared with healthy women. Eight obese PCOS (PO group), 10 nonobese PCOS (PN group), and nine healthy normal weight women (control) (C group) were enrolled. Insulin (INS), testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (E2), and dehydroepiandrosterone (DHEA) were detected with radioimmunoassay. Antimullerian hormone (AMH), fasting glucose, and hemoglobin A1c (HbA1c) were determined by a chemiluminescence immunoassay, glucose oxidase method, and HPLC, respectively. Gut microbiota composition was evaluated by PCR. Alpha diversity was assessed using Chao1 and the Shannon index. PCOS women showed significantly higher T, LH, and LH/FSH and lower FSH levels than the C group (p < 0.05). The AMH level was significantly higher in the PO than in the PN group (p < 0.05). The PO group presented a significantly higher fasting INS level and HMOA-IR scores than the other groups, lower observed SVs and alpha diversity than the C group, higher beta diversity than the PN group (p < 0.05), and decreased abundances of genera (mainly butyrate producers). Regression analysis showed that decreased abundances of several genera were correlated with higher circulating T and impaired glucose metabolism. PCOS is associated with changes in the gut microbiota composition. Obesity has a driving role in the development of dysbiotic gut microbiota in PCOS.

Metabolic dysfunction in polycystic ovary syndrome: Pathogenic role of androgen excess and potential therapeutic strategies

Background

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among reproductive age women. Although its cardinal manifestations include hyperandrogenism, oligo/anovulation, and/or polycystic ovarian morphology, PCOS women often display also notable metabolic comorbidities. An array of pathogenic mechanisms have been implicated in the etiology of this heterogeneous endocrine disorder; hyperandrogenism at various developmental periods is proposed as a major driver of the metabolic and reproductive perturbations associated with PCOS. However, the current understanding of the pathophysiology of PCOS-associated metabolic disease is incomplete, and therapeutic strategies used to manage this syndrome's metabolic complications remain limited.

Scope of review

This study is a systematic review of the potential etiopathogenic mechanisms of metabolic dysfunction frequently associated with PCOS, with special emphasis on the metabolic impact of androgen excess on different metabolic tissues and the brain. We also briefly summarize the therapeutic approaches currently available to manage metabolic perturbations linked to PCOS, highlighting current weaknesses and future directions.

Major conclusions

Androgen excess plays a prominent role in the development of metabolic disturbances associated with PCOS, with a discernible impact on key peripheral metabolic tissues, including the adipose, liver, pancreas, and muscle, and very prominently the brain, contributing to the constellation of metabolic complications of PCOS, from obesity to insulin resistance. However, the current understanding of the pathogenic roles of hyperandrogenism in metabolic dysfunction of PCOS and the underlying mechanisms remain largely incomplete. In addition, the development of more efficient, even personalized therapeutic strategies for the metabolic management of PCOS patients persists as an unmet need that will certainly benefit from a better comprehension of the molecular basis of this heterogeneous syndrome.

Curtailing PCOS

Polycystic ovary syndrome (PCOS), characterized by hormonal imbalance and ovarian dysfunction, often starts during adolescence. Inconsistent diagnostic criteria, variable provider knowledge, and lack of consensus pose specific challenges for the care of women with PCOS. These factors encourage inaccurate diagnosis with both under and overdiagnosis. This unfavorable diagnostic experience exasperates affected women and limits timely opportunities for intervention to minimize associated comorbidities, especially during the transition from pediatric to adult care. Recognition of these issues in the care of adolescents and women with PCOS inspired the development of the International Evidence-Based PCOS Guidelines, which emphasize the prevention, screening, and treatment of PCOS across the reproductive lifespan. The Guidelines and accompanying meta-analyses focus on three major categories of associated comorbidities: (1) reproductive; (2) metabolic; and (3) psychological. With the exception of infertility, this article considers common manifestations and comorbidities associated with PCOS throughout the lifecycle. Healthy lifestyle interventions with prevention of excess weight gain comprise the primary intervention for all comorbidities. Hence, early identification of girls "at risk" for PCOS and those with PCOS is a priority. Extensive guidelines for provider and patient education aim to decrease the medical, psychosocial, and economic burdens attributable to PCOS and its associated comorbidities.

Role of Anti-Müllerian Hormone in the Pathogenesis of Polycystic Ovary Syndrome

Besides its interest for diagnosis, the finding of an elevated serum AMH level in PCOS has open major pathophysiological issues. This review addresses the three most important issues: 1- the role of AMH in the disturbed folliculogenesis of PCOS; 2- the role of AMH in the gonadotropin dysregulation of PCOS and 3- the role of AMH in the trans-generational transmission of PCOS. For each of those issues, the clinical and experimental evidences currently available are discussed and pathophysiological hypothesis are proposed.

Prenatally androgenized female rats develop uterine hyperplasia when adult

Prenatal hyperandrogenization (PH) is hypothesized as one of the main factors contributing to the development of polycystic ovary syndrome (PCOS). In this study, we aimed to investigate the impact of prenatal exposure to androgen excess on the uterus when animals reach their adulthood. We found that PH altered the morphology of the uteri that show a hyperplastic morphology with increased total uterine thickness as well as luminal epithelium thickness, with both enhanced and altered distribution of glands as compared with controls. Morphological alterations were associated with an unbalanced homeostasis as assessed by the expression of regulators of cell cycle progression and cell death dynamics. PH also causes disturbances in the cell cycle of the uterine tissue and dysregulates cell death and survival pathways leading to the development of uterine hyperplasia. These findings suggest that PH may have a deleterious effect on the uterus.

Don't Trust Your Gut: When Gut Microbiota Disrupt Fertility

Emerging evidence indicates that the composition of the gut microbiome might affect metabolic homeostasis as well as reproductive fitness in women. In Nature Medicine, a new study by Qi et al. (2019), provides exciting insights into how gut microbiota dysbiosis may drive development of polycystic ovary syndrome (PCOS) and insulin resistance.

Neuroendocrine Impairments of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a prevalent and distressing disorder of largely unknown etiology. Although PCOS defined by ovarian dysfunction, accumulating evidence supports a critical role for the brain in the ontogeny and pathophysiology of PCOS. A critical pathological feature of PCOS is impaired gonadal steroid hormone negative feedback to the GnRH neuronal network in the brain that regulates fertility. This impairment is associated with androgen excess, a cardinal feature of PCOS. Impaired steroid hormone feedback to GnRH neurons is thought to drive hyperactivity of the neuroendocrine axis controlling fertility, leading to a vicious cycle of androgen excess and reproductive dysfunction. Decades of clinical research have been unable to uncover the mechanisms underlying this impairment, because of the extreme difficulty in studying the brain in humans. It is only recently, with the development of preclinical models of PCOS, that we have begun to unravel the role of the brain in the development and progression of PCOS. Here, we provide a succinct overview of what is known about alterations in the steroid hormone-sensitive GnRH neuronal network that may underlie the neuroendocrine defects in clinical PCOS, with a particular focus on those that may contribute to impaired progesterone negative feedback, and the likely role of androgens in driving this impairment.

The diagnosis and treatment of PCOS in adolescents: an update

PURPOSE OF REVIEW

Polycystic ovary syndrome (PCOS) is often difficult to diagnose in adolescents. Recent recommendations and concepts regarding the diagnosis and treatment of PCOS in the adolescent girl are considered.

RECENT FINDINGS

The diagnosis of PCOS in adolescents should be primarily based on clinical and biochemical signs of hyperandrogenism and presentation with irregular menses. Because of the similarity of normal pubertal development and features of PCOS, the diagnosis should be deferred until at least 2 years following menarche. For girls who do not fulfill the diagnostic criteria, the focus should be on treatment of symptoms.

SUMMARY

PCOS is a complex, multifaceted disorder, and should be diagnosed and treated in adolescents after taking into consideration the patient's full diagnostic picture, metabolic risks, and individual concerns, to both avoid overdiagnosis but yet be able to provide early and meaningful interventions.

Hyperandrogenic origins of polycystic ovary syndrome - implications for pathophysiology and therapy

INTRODUCTION

Polycystic ovary syndrome (PCOS) diagnosis comprises combinations of female hyperandrogenism, menstrual irregularity and polycystic ovaries. While it is a familial and highly prevalent endocrine disorder, progress towards a cure is hindered by absence of a definitive pathogenic mechanism and lack of an animal model of naturally occurring PCOS.

AREAS COVERED

These include an overview of PCOS and its potential etiology, and an examination of insights gained into its pathogenic origins. Animal models derived from experimentally-induced hyperandrogenism during gestation, or from naturally-occurring PCOS-like traits, most reliably demonstrate reproductive, neuroendocrine and metabolic pathogenesis.

EXPERT OPINION

Genetic studies, while identifying at least 17 PCOS risk genes, account for <10% of women with PCOS. A number of PCOS risk genes involve regulation of gonadotropin secretion or action, suggesting a reproductive neuroendocrine basis for PCOS pathogenesis. Consistent with this notion, a number of animal models employing fetal androgen excess demonstrate epigenetic induction of PCOS-like traits, including reproductive neuroendocrine and metabolic dysfunction. Monkey models are most comprehensive, while mouse models provide molecular insight, including identifying the androgen receptor, particularly in neurons, as mediating androgen-induced PCOS-like programming. Naturally-occurring female hyperandrogenism is also demonstrated in monkeys. Animal models are poised to delineate molecular gateways to PCOS pathogenesis.

Is polycystic ovary syndrome a 20th Century phenomenon?

Polycystic ovary syndrome (PCOS) affects around 10% of women of reproductive age and is most common in developed countries. The aetiology of PCOS is not completely understood. Current evidence suggests that the syndrome results from a genetic predisposition interacting with developmental events during fetal or perinatal life that together increase susceptibility in some individuals. This implies that environmental factors influence the initiation of PCOS in the fetus or infant, either directly or via the mother. PCOS is often considered to be an ancient disorder but there is no direct proof of this in the medical or historic record. One of the cardinal features, polycystic ovaries, was first described only in the early 1900s, despite reports of many thousands of autopsies recorded earlier. This conundrum could be explained by postulating that polycystic ovaries were rare before the 1900s and have become more common over the last 100 years. The hypothesis that PCOS is a syndrome of the 20th Century would eliminate the need to explain the paradox of why there exists a genetic predisposition to subfertility syndrome.

Vitamin D and probiotic co-supplementation affects mental health, hormonal, inflammatory and oxidative stress parameters in women with polycystic ovary syndrome

Objective

The aim of this study was to determine the effect of vitamin D and probiotic co-administration on mental health, hormonal, inflammatory and oxidative stress parameters in women with polycystic ovary syndrome (PCOS).

Methods

This randomized, double-blinded, placebo-controlled clinical trial was carried out on 60 subjects, aged 18–40 years old. Subjects were randomly allocated to take either 50,000 IU vitamin D every 2 weeks plus 8 × 10⁹ CFU/day probiotic (n = 30) or placebo (n = 30) for 12 weeks.

Results

Vitamin D and probiotic co-supplementation, compared with the placebo, significantly improved beck depression inventory [β (difference in the mean of outcomes measures between treatment groups) − 0.58; 95% CI, − 1.15, − 0.02; P = 0.04], general health questionnaire scores (β − 0.93; 95% CI, − 1.78, − 0.08; P = 0.03) and depression, anxiety and stress scale scores (β − 0.90; 95% CI, − 1.67, − 0.13; P = 0.02). Vitamin D and probiotic co-supplementation was associated with a significant reduction in total testosterone (β − 0.19 ng/mL; 95% CI, − 0.28, − 0.10; P < 0.001), hirsutism (β − 0.95; 95% CI, − 1.39, − 0.51; P < 0.001), high-sensitivity C-reactive protein (hs-CRP) (β − 0.67 mg/L; 95% CI, − 0.97, − 0.38; P < 0.001) and malondialdehyde (MDA) levels (β − 0.25 μmol/L; 95% CI, − 0.40, − 0.10; P = 0.001), and a significant increase in total antioxidant capacity (TAC) (β 82.81 mmol/L; 95% CI, 42.86, 122.75; P < 0.001) and total glutathione (GSH) levels (β 40.42 μmol/L; 95% CI, 4.69, 76.19; P = 0.02), compared with the placebo.

Conclusions

Overall, the co-administration of vitamin D and probiotic for 12 weeks to women with PCOS had beneficial effects on mental health parameters, serum total testosterone, hirsutism, hs-CRP, plasma TAC, GSH and MDA levels.

Trial Registration

This study was retrospectively registered in the Iranian website (www.irct.ir) for registration of clinical trials (IRCT20170513033941N37).

Emerging Roles of Anti-Müllerian Hormone in Hypothalamic-Pituitary Function

Since its initial discovery in the 1940s, research into the physiological actions of anti-Müllerian hormone (AMH), from its eponymous role in male developmental biology to its routine clinical use in female reproductive health, has undergone a paradigm shifting change. With several exciting studies recently reporting hitherto unforeseen AMH actions at all levels in the hypogonadal-pituitary-gonadal axis, the importance of this hormone for both hypothalamic and pituitary reproductive control is finding increasing support and significance. In this review, we will briefly summarize what is known about the traditional roles and biology of AMH and how this could be integrated with new findings of AMH actions at the level of the hypothalamic-pituitary axis. We also synthesize the important findings from these new studies and discuss their potential impact and significance to our understanding of one of the most common reproductive disorders currently affecting women, polycystic ovary syndrome.