Clinical and biochemical discriminants between functional hypothalamic amenorrhoea (FHA) and polycystic ovary syndrome (PCOS)

GnRH ability to release FSH and LH in women with functional hypothalamic amenorrhea: a retrospective cohort study about women with and without polycystic ovarian morphology

Nearly 50% of women with functional hypothalamic amenorrhea (FHA) reveal polycystic ovarian morphology (PCOM), a known risk factor for ovarian hyperstimulation syndrome. However, gonadotropin releasing hormone-agonist (GnRH-a) triggers are not recommended in FHA, since an inadequate endogenous surge in luteinizing hormone (LH) is expected. We aimed to challenge this concept and evaluated LH levels after GnRH stimulation in FHA-women with and without PCOM. In a retrospective cohort study, 82 women with FHA, who underwent a GnRH stimulation test, were included. Thirty-five women revealed PCOM (42.7%). Twenty minutes after GnRH stimulation, there was an increase of serum LH levels in FHA-PCOM (median basal: 2.7 mIU/mL, IQR 1.1-4.6 versus median stimulated: 13.5 mIU/mL, IQR 7.8-21.6, p < 0.001) and in FHA-nonPCOM patients (median basal: 2.5 mIU/mL, IQR 0.5-3.9 versus median stimulated: 5.7 mIU/mL, IQR 2.4-13.9, p < 0.001). Overall, positive correlations (p < 0.001) were found between basal and stimulated LH levels. In FHA-PCOM patients, 42.9% of patients revealed stimulated LH levels >15 mIU/mL, while this was the case in 19.1% of FHA-nonPCOM patients (p = 0.034). In women with FHA-PCOM, ovulation induction with a GnRH-a trigger might be feasible. Future research should focus on the prediction of an adequate response to GnRH triggers in the IVF setting.

Intranasal kisspeptin administration rapidly stimulates gonadotropin release in humans

BACKGROUND

Kisspeptin administration by intravenous or subcutaneous routes activates hypothalamic gonadotropin-releasing hormone (GnRH) neurons and is being developed to treat reproductive disorders. However, these invasive routes markedly limit patient acceptability and clinical use. Recent rodent data has identified a large GnRH population within the olfactory system communicating directly with hypothalamic GnRH neurons. Intranasal kisspeptin administration may be able to capitalise on this novel pathway and thus offer a potential non-invasive approach to stimulate reproductive hormones. Herein, we examine intranasal kisspeptin using human, pharmaceutical, and rodent studies.

METHODS

Reproductive hormone profiles were measured after intranasal kisspeptin administration in healthy volunteers and patients with reproductive disorders as part of a randomised, double-blinded, crossover, placebo-controlled clinical study. Pharmaceutical testing evaluated the chemical stability and nasal kisspeptin delivery, and rodent studies provided mechanistic insight.

FINDINGS

Intranasal kisspeptin-54 rapidly stimulates gonadotropin release in healthy men and women, and in patients with a common reproductive disorder (hypothalamic amenorrhoea), without any side effects or adverse events encountered. Specifically, intranasal kisspeptin (at 12.8 nmol/kg) induced clinically-significant mean maximal increases above baseline in serum luteinising hormone in all study groups: 4.4 ± 0.6 IU/L (mean difference = 3.1 IU/L [95% CI, 1.2-4.9], P = 0.002 vs. placebo) in healthy men; 1.4 ± 0.3 IU/L (mean difference = 1.0 IU/L [95% CI, 0.4-1.7], P = 0.004 vs. placebo) in healthy women; 4.4 ± 0.2 IU/L (mean difference = 4.3 IU/L [95% CI, 2.7-6.0], P < 0.001 vs. placebo) in patients with hypothalamic amenorrhoea. Kisspeptin-54 was delivered effectively via nasal spray and was stable for up to 60 days at 4 °C. Mirroring the human effects, intranasal kisspeptin-54 in adult C57BL/6J male mice stimulates luteinising hormone release. Further mechanistic insights reveal the accumulation of fluorescently-tagged kisspeptin in the olfactory epithelium, as well as the presence of kisspeptin receptors in olfactory bulb GnRH neurons, implicating the involvement of these extra-hypothalamic GnRH neurons in the pathway mediating intranasal kisspeptin's effects on reproductive hormones.

INTERPRETATION

We demonstrate the clinical potential for intranasal kisspeptin delivery as the first non-invasive method to robustly and safely stimulate gonadotropins with kisspeptin and potentially transform the management of reproductive disorders.

FUNDING

National Institute for Health and Care Research (NIHR)/NIHR Imperial Biomedical Research Centre/Medical Research Council (MRC).

Gonadotropin-releasing hormone regulates transcription of the inhibin B co-receptor, TGFBR3L, via early growth response one

Follicle-stimulating hormone (FSH), a product of pituitary gonadotrope cells, regulates gonadal function and fertility. FSH production is stimulated by gonadotropin-releasing hormone (GnRH) and activin-class ligands of the TGFβ family. Inhibin A and B are TGFβ proteins that suppress FSH synthesis by competitively binding activin type II receptors in concert with the co-receptors betaglycan (TGFBR3) and TGFBR3L. Betaglycan mediates the actions of both inhibins and is broadly expressed. In contrast, TGFBR3L is inhibin B-specific and selectively expressed in gonadotropes. This cell-restricted expression is driven, in part, by steroidogenic factor 1 (SF-1, NR5A1), which stimulates Tgfbr3l/TGFBR3L transcription via two conserved promoter elements. Tgfbr3l expression is lost in mice lacking SF-1 in gonadotropes. However, SF-1 alone is unlikely to fully explain gonadotrope-restricted Tgfbr3l/TGFBR3L expression. Here, we report that GnRH induces binding of the transcription factor, early growth response 1 (EGR1), to the murine Tgfbr3l and human TGFBR3L promoters at a conserved cis-element between the two SF-1 binding sites. In homologous LβT2 cells, GnRH stimulation of Tgfbr3l/TGFBR3L promoter-reporters depends on EGR1 binding to this cis-element. In heterologous cells, over-expressed EGR1 independently and synergistically with SF-1 activates Tgfbr3l/TGFBR3L promoter-reporter activities. In vivo, Tgfbr3l mRNA expression is reduced in the pituitaries of: 1) GnRH-deficient mice, 2) wild-type mice treated with a GnRH receptor antagonist, and 3) gonadotrope-specific Egr1 knockout mice. Gonadectomy, which increases GnRH pulse frequency, enhances Tgfbr3l expression in control but not gonadotrope-specific Egr1 knockouts. Collectively, these data indicate that GnRH stimulates Tgfbr3l/TGFBR3L transcription via EGR1, which acts with SF-1 through conserved promoter elements.

Ovarian function measures in normogonadotropic anovulation and subclinical thyroid dysfunction: a prospective cohort study

PURPOSE

To compare ovarian function measures in euthyroid women with normogonadotropic anovulation in subclinical hypothyroidism (SCH) or thyroid autoimmunity (TAI) to those without thyroid dysfunction.

DESIGN

A prospective open-label cohort study analyzed anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone, estradiol and testosterone concentrations, ovarian volume, and polycystic ovarian morphology (PCOM) incidence between women with and without SCH or TAI in two study arms: polycystic ovary syndrome (PCOS) and hypothalamic-pituitary-ovarian dysfunction (HPOD).

RESULTS

The prevalence of circulating thyroid peroxidase antibodies (TPOAb) was higher in the PCOS compared to the HPOD arm (p = 0.006). No significant differences in the measured parameters were observed based on SCH or TAI status across the entire cohort or individual study arms, except for phenotype D of PCOS, where a greater volume (p = 0.031) and higher incidence of physiological lesions (p = 0.047) in the left ovary were noted in SCH, and phenotype A, where LH concentrations (p = 0.038) were significantly higher in women without TAI. In the PCOS arm, thyroglobulin antibodies (TGAb) concentration correlated negatively with FSH (p = 0.049) and positively with testosterone (p = 0.012) concentrations, while in the HPOD arm, TPOAb and FSH concentrations were negatively correlated (p = 0.028).

CONCLUSIONS

No clinically significant impact of SCH on ovarian function measures was demonstrated. Regarding TAI, significant correlations with still uncertain clinical significance were observed with FSH concentrations, both in PCOS and in HPOD. In view of the obtained results, the benefits of thyroxine supplementation to address menstrual irregularities and improve obstetric outcomes in the examined conditions, require support with clinical evidence.

Kisspeptin and neurokinin B: roles in reproductive health

Kisspeptin and neurokinin B (NKB) play a key role in several physiological processes including in puberty, adult reproductive function including the menstrual cycle, as well as mediating the symptoms of menopause. Infundibular kisspeptin neurons, which coexpress NKB, regulate the activity of gonadotropin-releasing hormone (GnRH) neurons and thus the physiological pulsatile secretion of GnRH from the hypothalamus. Outside of their hypothalamic reproductive roles, these peptides are implicated in several physiological functions including sexual behavior and attraction, placental function, and bone health. Over the last two decades, research findings have considerably enhanced our understanding of the physiological regulation of the hypothalamic-pituitary-gonadal (HPG) axis and identified potential therapeutic applications. For example, recognition of the role of kisspeptin as the natural inductor of ovulation has led to research investigating its use as a safer, more physiological trigger of oocyte maturation in in vitro fertilization (IVF) treatment. Moreover, the key role of NKB in the pathophysiology of menopausal hot flashes has led to the development of pharmacological antagonism of this pathway. Indeed, fezolinetant, a neurokinin 3 receptor antagonist, has recently received Food and Drug Administration (FDA) approval for clinical use to treat menopausal vasomotor symptoms. Here, we discuss the roles of kisspeptin and NKB in human physiology, including in the regulation of puberty, menstrual cyclicity, reproductive behavior, pregnancy, menopause, and bone homeostasis. We describe how perturbations of these key physiological processes can result in disease states and consider how kisspeptin and NKB could be exploited diagnostically as well as therapeutically to treat reproductive disorders.

Probiotics ameliorates hypothalamic amenorrhea in a rat model of PCOS

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrinometabolic disorder affecting women of reproductive age, characterized by hormonal imbalances, irregular menstrual cycles, and often, infertility. Hypothalamic amenorrhea, a condition marked by the cessation of menstruation due to disruptions in the hypothalamic-pituitary-gonadal axis, is a frequent manifestation in PCOS. Probiotics, beneficial microorganisms known for improving metabolic health, have shown promise in restoring hormonal balance and enhancing fertility. In this study, we hypothesize that probiotics would ameliorate hypothalamic amenorrhea by modulating hypothalamic kisspeptin and reducing inflammation in a rat model of PCOS.

METHODS

Eight (8)-week-old female Wistar rats were grouped into four with n = 5. Letrozole administration (1 mg/kg, p.o.) for 21 days induced PCOS, thereafter the animals were treated with probiotics (3 × 109 CFU, p.o.), while control animals received distilled water. The treatment lasted for six weeks.

RESULTS

Reduced insulin sensitivity, hyperinsulinemia, ovarian dysfunction with evidence of disrupted steroid hormone levels (testosterone/17β-Estradiol) and cystic follicles as well as hypothalamic lipid accumulation, elevated inflammatory markers (NF-kB/TNF-α) and antioxidant depletion (GSH/NrF2), which are accompanied by decreased level of kisspeptin. Nonetheless, administration of probiotics reversed these pathological alterations by enhancement of hypothalamic kisspeptin and suppression of inflammatory response.

CONCLUSIONS

Altogether, the present results demonstrate that probiotics significantly ameliorated hypothalamic amenorrhea by mitigating hypothalamic lipid accumulation, suppressed inflammation, and replenished antioxidants. Crucially, probiotics enhanced hypothalamic kisspeptin levels, a key regulator of reproductive function, highlighting their potential as a therapeutic strategy for restoring ovarian function in PCOS.

GnRH pulse generator activity in mouse models of polycystic ovary syndrome

One in ten women in their reproductive age suffer from polycystic ovary syndrome (PCOS) that, alongside subfertility and hyperandrogenism, typically presents with increased luteinizing hormone (LH) pulsatility. As such, it is suspected that the arcuate kisspeptin (ARNKISS) neurons that represent the GnRH pulse generator are dysfunctional in PCOS. We used here in vivo GCaMP fiber photometry and other approaches to examine the behavior of the GnRH pulse generator in two mouse models of PCOS. We began with the peripubertal androgen (PPA) mouse model of PCOS but found that it had a reduction in the frequency of ARNKISS neuron synchronization events (SEs) that drive LH pulses. Examining the prenatal androgen (PNA) model of PCOS, we observed highly variable patterns of pulse generator activity with no significant differences detected in ARNKISS neuron SEs, pulsatile LH secretion, or serum testosterone, estradiol, and progesterone concentrations. However, a machine learning approach identified that the ARNKISS neurons of acyclic PNA mice continued to exhibit cyclical patterns of activity similar to that of normal mice. The frequency of ARNKISS neuron SEs was significantly increased in algorithm-identified 'diestrous stage' PNA mice compared to controls. In addition, ARNKISS neurons exhibited reduced feedback suppression to progesterone in PNA mice and their gonadotrophs were also less sensitive to GnRH. These observations demonstrate the importance of understanding GnRH pulse generator activity in mouse models of PCOS. The existence of cyclical GnRH pulse generator activity in the acyclic PNA mouse indicates the presence of a complex phenotype with deficits at multiple levels of the hypothalamo-pituitary-gonadal axis.

Functional hypothalamic amenorrhoea and polycystic ovarian morphology: a narrative review about an intriguing association

BACKGROUND

Functional hypothalamic amenorrhoea (FHA) is responsible for 20-35% of all cases of secondary amenorrhoea and, thus, is the second most common cause of secondary amenorrhoea after polycystic ovary syndrome (PCOS). A high number of patients with FHA reveal polycystic ovarian morphology (PCOM) on ultrasound. The combination of amenorrhoea and PCOM can lead to confusion. First, amenorrhoeic women with PCOM fulfil the revised Rotterdam criteria and, thus, can easily be misdiagnosed with PCOS. Moreover, it has been claimed that some women with FHA and concomitant PCOM differ from those without PCOM in terms of endocrine regulation and metabolic traits.

OBJECTIVE AND RATIONALE

The main focus of this article was on studies about FHA, which differentiated between patients with or without PCOM. The aim was to estimate the prevalence of PCOM and to look if it has an impact on pathophysiologic, diagnostic and therapeutic issues as well as on long-term consequences.

SEARCH METHODS

Peer review original and review articles were selected from PubMed searches for this review. Searches were performed using the search terms 'polycystic AND functional hypothalamic amenorrhoea'. The reference lists of publications found were searched for relevant additional studies. The inclusion criteria for publications were: English language, patients' age ≥ 18 years, year of publication >1980, original studies, validated diagnosis of FHA, and validated diagnosis of PCOM using transvaginal ultrasound.

OUTCOMES

The prevalence of PCOM in women with FHA varied from 41.9% to 46.7%, which is higher than in healthy non-PCOS controls. Hypothetically, the high prevalence might be due to a mixture of silent PCOM, as in the general population, and pre-existing PCOS. Several differences in metabolic and hormonal parameters were found between FHA-PCOM and FHA-non-PCOM patients. While oestrogen deficiency is common to both groups of patients, FHA-PCOM patients have a higher BMI, higher levels of anti-Müllerian hormone (AMH) and testosterone, a higher increase in LH in the course of a GnRH test, and lower sex hormone binding globulin (SHBG) levels than FHA-non-PCOM patients. The differential diagnosis between FHA-PCOM and PCOS, especially PCOS phenotype D (PCOM and oligo-/anovulation without hyperandrogenism), can be challenging. Several parameters have been suggested, which are helpful though not absolutely reliable. They include the typical causes for FHA (excessive exercise, energy deficit, and/or psychological stress), the serum levels of LH, testosterone, and SHBG, as well as the progestin challenge test. Whether FHA-PCOM has a different risk profile for long-term consequences concerning patients' metabolic and cardiovascular situation as well as their bone mass, is unclear. Concerning therapeutic aspects, there are only few data about FHA-PCOM compared to FHA-non-PCOM. To treat anovulation, the use of pulsatile GnRH treatment seems to be equally effective in both groups. Similar to FHA-non-PCOM patients, pulsatile GnRH therapy would be more efficient than exogenous gonadotropins in FHA-PCOM patients.

WIDER IMPLICATIONS

Women with FHA-PCOM present a special sub-population of FHA patients. The diagnostic pitfall of FHA-PCOM should be emphasized in clinical guidelines about FHA and PCOS. The fact that almost half of the women with FHA have an ovarian follicle excess (i.e. PCOM) in face of low gonadotropin serum levels suggests that the intra-ovarian regulation of folliculogenesis is subject to individual variations, for unknown reasons, either genetic or epigenetic. Further studies are needed to investigate this hypothesis.

REGISTRATION NUMBER

Not applicable.

Analysis of the effects of eating and emotions on reproductive axis function in patients with functional hypothalamic amenorrhea

Objective: To investigate the effects of eating and emotions on reproductive axis function in patients with functional hypothalamic amenorrhea (FHA).

Methods: A retrospective cohort study was conducted to summarize the clinical and endocrine characteristics of 58 patients with FHA at initial diagnosis and to follow up the recovery of ovulation and spontaneous menstruation in the patients to investigate these biochemical indicators and their effects on recovery outcomes.

Results: Among patients with FHA, 13.8% (8/58) and 15.5% (9/58) had above moderately severe depressive and severe anxiety symptoms respectively, and 25.9% (15/58) were at high risk for eating disorders. 34.5% (20/58) were included assessed as having recovered. The non-recovered group had higher scores on the Patient Health Questionnaire (PHQ-9) (p = .022) and higher scores on the Eating Attitude Test-26 (EAT-26) (p = .03) as well as bulimia and food preoccupation (p = .041). Follicle diameter >5 mm at initial diagnosis was an independent factor influencing recovery of reproductive axis function (odds ratio = 7.532; 95% confidence interval, 1.321-42.930; p = .023).

Conculsions: Mood disorders and a certain risk of eating disorders were present in FHA.These, together with weight loss, endocrine and follicle size, could influence the outcome.

[Difficulties of differential diagnosis of functional hypothalamic amenorrhea and polycystic ovary syndrome: a systematic review]

BACKGROUND

Functional hypothalamic amenorrhea (FHA) and polycystic ovary syndrome (PCOS) are pathologies most common in women of reproductive age. Menstrual irregularities (oligo/amenorrhea) are the most common symptom of these diseases. FHA develops against the background of stress or excessive physical exertion, and is characterized by inhibition of neuroendocrine regulation of the hypothalamic-pituitary-ovarian axis with a subsequent decrease in the production of sex steroids. For PCOS, the most important pathogenetic links are insulin resistance and hyperandrogenism. The pathology of neuroendocrine regulation in ovarian hyperandrogenism is accompanied by excessive pulsatile secretion of gonadotropin-releasing hormone (GnRH), promoting increased production of luteinizing hormone (LH). Both FHA and PCOS lead to multiple complications from other organs and systems: cardiovascular pathology, decreased bone mineral density with prolonged amenorrhea and contribute to the development of infertility.

OBJECTIVE

To analyze the works studying the problems of differential diagnosis of FHA and PCOS.

METHODS

Using PubMed, eLibrary, CyberLeninka.ru, a systematic search was conducted for articles published over the past 6 years that met the following criteria: the research that describe methods and develop criteria for the differential diagnosis of FHA and PCOS. Selected impactive publications within 1998-2018 were also included in the review.

RESULTS

This review highlights the differential diagnostic criteria for FHA and PCOS. The features of clinical, laboratory and instrumental studies are also described. Publications describing the coexistence of these pathologies in women are analyzed, and methods that allow differentiating these nosologies are described in detail.

CONCLUSION

A correct and timely diagnosis facilitates the prescription of appropriate treatment regimens, reduces the incidence of complications and improves the quality of life of women. In light of recent advances in the description of the mechanisms of neuroendocrine regulation of the reproductive system, it is necessary to further conduct research to study the role of neuropeptides in the development of FHA and PCOS, which may serve to create more accurate diagnostic markers of diseases.

Kisspeptin in functional hypothalamic amenorrhea: Pathophysiology and therapeutic potential

Functional hypothalamic amenorrhea (FHA) is one of the most common causes of secondary amenorrhea, resulting in anovulation and infertility, and is a low estrogen state that increases the risk of cardiovascular disease and impairs bone health. FHA is characterized by acquired suppression of physiological pulsatile gonadotropin-releasing hormone (GnRH) release by the hypothalamus in the absence of an identifiable structural cause, resulting in a functional hypogonadotropic hypogonadism. FHA results from either decreased energy intake and/or excessive exercise, leading to low energy availability and weight loss-often in combination with psychological stress on top of a background of genetic susceptibility. The hypothalamic neuropeptide kisspeptin is a key component of the GnRH pulse generator, tightly regulating pulsatile GnRH secretion and the downstream reproductive axis. Here, we review the physiological regulation of pulsatile GnRH secretion by hypothalamic kisspeptin neurons and how their activity is modulated by signals of energy status to affect reproductive function. We explore endocrine factors contributing to the suppression of GnRH pulsatility in the pathophysiology of FHA and how hypothalamic kisspeptin neurons likely represent a final common pathway through which these factors affect GnRH pulse generation. Finally, we discuss the therapeutic potential of kisspeptin as a novel treatment for women with FHA.

Impact of the difference in diagnostic criteria for adolescent polycystic ovary syndrome excluding polycystic ovarian morphology

AIM

Exclusion of polycystic ovarian morphology (PCOM) from the diagnostic criteria for adolescent polycystic ovary syndrome (PCOS) has been proposed. We analyzed the profiles of adolescent women with suspected PCOS based on the Japan Society of Obstetrics and Gynecology (JSOG) diagnostic and Rotterdam criteria, excluding those with PCOM.

METHODS

Thirteen- to twenty-one-year-old women with suspected or confirmed diagnosis of PCOS according to the JSOG and Rotterdam criteria were included in this study. Patient characteristics such as hormone levels and body mass index (BMI) were compared between the groups. Correlations between BMI and testosterone, and BMI and time to diagnosis were also analyzed.

RESULTS

Twenty-nine patients were diagnosed with adolescent PCOS according to the JSOG criteria, and 11 patients according to the Rotterdam criteria after excluding the patients fulfilling the PCOM criteria. Serum testosterone levels were significantly higher in adolescents diagnosed with PCOS using the Rotterdam criteria than in those diagnosed using the JSOG criteria (p < 0.001). The obese group had significantly higher testosterone levels and a longer time from menarche to PCOS diagnosis. A positive correlation was observed between BMI and testosterone levels (r = 0.318, p = 0.014).

CONCLUSION

Although adolescents with PCOS diagnosed using the Rotterdam criteria exhibited higher testosterone levels, which is a typical characteristic of this condition, the JSOG criteria may be useful for the early diagnosis of adolescent PCOS, including suspected cases. The differences between the two criteria may reflect the natural history of PCOS and its different reproductive and metabolic phenotypes.

Neuroendocrine disturbances in women with functional hypothalamic amenorrhea: an update and future directions

Functional hypothalamic amenorrhea (FHA) is one of the most common causes of both primary and secondary amenorrhea in women of reproductive age. It is characterized by chronic anovulation and the absence of menses that appear as a result of stressors such as eating disorders, excessive exercise, or psychological distress. FHA is presumed to be a functional disruption in the pulsatile secretion of hypothalamic gonadotropin-releasing hormone, which in turn impairs the release of gonadotropin. Hypoestrogenism is observed due to the absence of ovarian follicle recruitment. Numerous neurotransmitters have been identified which play an important role in the regulation of the hypothalamic-pituitary-ovarian axis and of which the impairment would contribute to developing FHA. In this review we summarize the most recent advances in the identification of contributing neuroendocrine disturbances and relevant contributors to the development of FHA.

Dehydroepiandrosterone with a high-fat diet treatment at inducing polycystic ovary syndrome in rat model

OBJECTIVE

This study aimed to evaluate the effects of dehydroepiandrosterone (DHEA) and DHEA combined with a high-fat diet (HFD) treatment of reproductive and endocrine metabolism in rats and then identify an ideal model of polycystic ovary syndrome (PCOS).

METHODS

Three-week-old female Sprague-Dawley rats were injected subcutaneously with DHEA or oil, fed with or without a HFD, for 21 days, during which body weight, feed intake, and estrous cycle monitoring were carried out. Fasting blood glucose was measured, and serum fasting insulin, testosterone, dihydrotestosterone (DHT), estradiol, progesterone, luteinizing hormone (LH), anti-Müllerian hormone (AMH), and follicle-stimulating hormone (FSH) were estimated by ELISA. Serum total cholesterol (TC), total triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured by colorimetric assay. Whereas, histologic changes in rat ovaries were evaluated by H&E staining. Ovarian steroid hormone synthases and their protein levels (StAR, 3β-HSD2, 17β-HSD1, CYP11A1, CYP17A1, and CYP19A1) were examined by Western blotting.

RESULTS

Both DHEA and DHEA + HFD-treated rats lost a regular estrous cycle; had polycystic ovarian changes, significantly higher serum fasting insulin and testosterone levels; and increased ovarian StAR, 3β-HSD2, and CYP11A1 protein levels. Additionally, rats in the DHEA + HFD-treated group were obese; had elevated fasting blood glucose, TG, DHT, AMH levels and LH:FSH ratios; increased ovarian 17β-HSD1 protein levels.

CONCLUSION

DHEA combined with HFD treatment is more effective at inducing PCOS than DHEA alone. The reproductive and endocrine metabolic aspects of this method are more consistent with the clinical characteristics of PCOS patients.

Irregular Cycles, Ovulatory Disorders, and Cardiometabolic Conditions in a US-Based Digital Cohort

Importance

Polycystic ovary syndrome (PCOS), characterized by irregular menstrual cycles and hyperandrogenism, is a common ovulatory disorder. Having an irregular cycle is a potential marker for cardiometabolic conditions, but data are limited on whether the associations differ by PCOS status or potential interventions.

Objective

To evaluate the association of PCOS, time to regularity since menarche (adolescence), and irregular cycles (adulthood) with cardiometabolic conditions.

Design, Setting, and Participants

This cross-sectional study used a large, US-based digital cohort of users of the Apple Research application on their iPhone. Eligibility criteria were having ever menstruated, living in the US, being at age of consent of at least 18 years (or 19 years in Alabama and Nebraska or 21 years in Puerto Rico), and being able to communicate in English. Participants were enrolled between November 14, 2019, and December 13, 2022, and completed relevant surveys.

Exposures

Self-reported PCOS diagnosis, prolonged time to regularity (not spontaneously establishing regularity within 5 years of menarche), and irregular cycles.

Main Outcomes and Measures

The primary outcome was self-reported cardiometabolic conditions, including obesity, prediabetes, type 1 and 2 diabetes, high cholesterol, hypertension, metabolic syndrome, arrhythmia, congestive heart failure, coronary artery disease, heart attack, heart valve disease, stroke, transient ischemic attack (TIA), deep vein thrombosis, and pulmonary embolism measured using descriptive statistics and logistic regression to estimate prevalence odds ratios (PORs) and 95% CIs. Effect modification by lifestyle factors was also estimated.

Results

The study sample (N = 60 789) had a mean (SD) age of 34.5 (11.1) years, with 12.3% having PCOS and 26.3% having prolonged time to regularity. Among a subset of 25 399 participants who completed the hormonal symptoms survey, 25.6% reported irregular cycles. In covariate-adjusted logistic regression models, PCOS was associated with a higher prevalence of all metabolic and several cardiovascular conditions, eg, arrhythmia (POR, 1.37; 95% CI, 1.20-1.55), coronary artery disease (POR, 2.92; 95% CI, 1.95-4.29), heart attack (POR, 1.79; 95% CI, 1.23-2.54), and stroke (POR, 1.66; 95% CI, 1.21-2.24). Among participants without PCOS, prolonged time to regularity was associated with type 2 diabetes (POR, 1.24; 95% CI, 1.05-1.46), hypertension (POR, 1.09; 95% CI, 1.01-1.19), arrhythmia (POR, 1.20; 95% CI, 1.06-1.35), and TIA (POR, 1.33; 95% CI, 1.01-1.73), and having irregular cycles was associated with type 2 diabetes (POR, 1.36; 95% CI, 1.08-1.69), high cholesterol (POR, 1.17; 95% CI, 1.05-1.30), arrhythmia (POR, 1.21; 95% CI, 1.02-1.43), and TIA (POR, 1.56; 95% CI, 1.06-2.26). Some of these associations were modified by high vs low body mass index or low vs high physical activity.

Conclusions and Relevance

These findings suggest that PCOS and irregular cycles may be independent markers for cardiometabolic conditions. Early screening and intervention among individuals with irregular menstrual cycles may be beneficial.

Distribution and anthropometric characteristics of Rotterdam criteria-based phenotypic forms of Polycystic ovaries syndrome in Ukraine

OBJECTIVE

To explore the distribution of Rotterdam-based PCOS phenotypes and their associations with anthropometric parameters predictive of cardiometabolic risks in Ukrainian referral PCOS women.

STUDY DESIGN

It was a cross-sectional study conducted by the Ukrainian Society of Gynecological Endocrinology between September 2021 and January 2022 involving 42 clinics in 10 regional centres representing the major geographical parts of Ukraine. Two hundred obstetrician-gynecologists whose practice facilities corresponded to study criteria were committed to entering records of their PCOS patients aged 20-45 years into the uniform data collection forms. The recorded parameters were: PCOS phenotype with the mandatory assessment of biochemical hyperandrogenism, age, BMI, waist circumference, and hyperandrogenism symptoms.

RESULTS

5254 patients' records were completed. Phenotype A was the most prevalent - 47.7 %, phenotypes B, C, and D were almost equally distributed in the studied population: 17.6 %, 17.4 %, and 17.3 % respectively. The total prevalence of androgenic phenotypes based on the presence of biochemical hyperandrogenism was 82.7 %. The incidence of obesity and hyperandrogenism symptoms, and mean BMI values were higher in phenotypes A and B compared to C and D. At the same time, the presence of 34.1 % and 46.2 % of normal-weight subjects in phenotypes A and B respectively, supports the fact that the excessive BMI is not a universal characteristic of androgenic phenotypes. In younger age groups, phenotypes C and D demonstrated the predominance of normal weight, but in older subgroups, the situation changed: in the age group of 36-45 y.o. compared to 18-25 y.o., the percentage of overweight and obese subjects for the non-classic phenotypes increased more than for the classic ones: C (OR = 3.91, 95 % CI: 2.41-6.38), D (OR = 4.14, 95 % CI: 2.64-6.52), A (OR = 2.30, 95 % CI:1.72-2.08), and B (OR = 2.56, 95 % CI:1.69-3.89).

CONCLUSIONS

In thoroughly assessed Ukrainian referral PCOS population the classic phenotypes prevailed as in other clinical cohorts. The classic phenotypes were characterized by the higher rate of adiposity and severity of clinical hyperandrogenism. At the same time, obese, overweight, and normal-weight subjects were present in all phenotypes, and the risk of obesity in non-classic phenotypes was higher in older age groups.

Obesity-Related Hypogonadism in Women

Obesity-related hypogonadotropic hypogonadism is a well-characterized condition in men (termed male obesity-related secondary hypogonadism; MOSH); however, an equivalent condition has not been as clearly described in women. The prevalence of polycystic ovary syndrome (PCOS) is known to increase with obesity, but PCOS is more typically characterized by increased gonadotropin-releasing hormone (GnRH) (and by proxy luteinizing hormone; LH) pulsatility, rather than by the reduced gonadotropin levels observed in MOSH. Notably, LH levels and LH pulse amplitude are reduced with obesity, both in women with and without PCOS, suggesting that an obesity-related secondary hypogonadism may also exist in women akin to MOSH in men. Herein, we examine the evidence for the existence of a putative non-PCOS "female obesity-related secondary hypogonadism" (FOSH). We précis possible underlying mechanisms for the occurrence of hypogonadism in this context and consider how such mechanisms differ from MOSH in men, and from PCOS in women without obesity. In this review, we consider relevant etiological factors that are altered in obesity and that could impact on GnRH pulsatility to ascertain whether they could contribute to obesity-related secondary hypogonadism including: anti-Müllerian hormone, androgen, insulin, fatty acid, adiponectin, and leptin. More precise phenotyping of hypogonadism in women with obesity could provide further validation for non-PCOS FOSH and preface the ability to define/investigate such a condition.

The LH:FSH Ratio in Functional Hypothalamic Amenorrhea: An Observational Study

BACKGROUND

In functional hypothalamic amenorrhea (FHA), luteinizing hormone and follicle-stimulating hormone levels show high interindividual variability, which significantly limits their diagnostic value in differentiating FHA from polycystic ovary syndrome (PCOS). Our aim was to profile the LH:FSH ratio in a large sample of patients with well-defined FHA.

METHODS

This observational study included all consecutive patients with FHA presenting to the Department of Gynecologic Endocrinology and Reproductive Medicine, Medical University of Vienna, between January 2017 and August 2023. The main parameters of interest were the LH level, the FSH level, and the LH:FSH ratio. In a subgroup analysis, we compared the LH:FSH ratio of patients with PCO morphology (PCOM) on ultrasound with that of patients without PCOM.

RESULTS

A total of 135 patients were included. Only a minority of patients revealed FSH and LH levels ≤ 2.0 mIU/mL (13% and 39%, respectively). Most patients (81.5%) had an LH:FSH ratio ≤ 1.0, while a minority (2.2%) had a ratio ≥ 2.1. The LH:FSH ratio was similar in patients with and without PCOM.

CONCLUSION

In a well-defined FHA sample, the LH:FSH ratio was ≤ 1 in most patients. The LH:FSH ratio may prove useful in distinguishing FHA from PCOS but needs further investigation.

Quantifying the variability in the assessment of reproductive hormone levels

OBJECTIVE

To quantify how representative a single measure of reproductive hormone level is of the daily hormonal profile using data from detailed hormonal sampling in the saline placebo-treated arm conducted over several hours.

DESIGN

Retrospective analysis of data from previous interventional research studies evaluating reproductive hormones.

SETTING

Clinical Research Facility at a tertiary reproductive endocrinology centre at Imperial College Hospital NHS Foundation Trust.

PATIENTS

Overall, 266 individuals, including healthy men and women (n = 142) and those with reproductive disorders and states (n = 124 [11 with functional hypothalamic amenorrhoea, 6 with polycystic ovary syndrome, 62 women and 32 men with hypoactive sexual desire disorder, and 13 postmenopausal women]), were included in the analysis.

INTERVENTIONS

Data from 266 individuals who had undergone detailed hormonal sampling in the saline placebo-treated arms of previous research studies was used to quantify the variability in reproductive hormones because of pulsatile secretion, diurnal variation, and feeding using coefficient of variation (CV) and entropy.

MAIN OUTCOME MEASURES

The ability of a single measure of reproductive hormone level to quantify the variability in reproductive hormone levels because of pulsatile secretion, diurnal variation, and nutrient intake.

RESULTS

The initial morning value of reproductive hormone levels was typically higher than the mean value throughout the day (percentage decrease from initial morning measure to daily mean: luteinizing hormone level 18.4%, follicle-stimulating hormone level 9.7%, testosterone level 9.2%, and estradiol level 2.1%). Luteinizing hormone level was the most variable (CV 28%), followed by sex-steroid hormone levels (testosterone level 12% and estradiol level 13%), whereas follicle-stimulating hormone level was the least variable reproductive hormone (CV 8%). In healthy men, testosterone levels fell between 9:00 am and 5:00 pm by 14.9% (95% confidence interval 4.2, 25.5%), although morning levels correlated with (and could be predicted from) late afternoon levels in the same individual (r2 = 0.53, P<.0001). Testosterone levels were reduced more after a mixed meal (by 34.3%) than during ad libitum feeding (9.5%), after an oral glucose load (6.0%), or an intravenous glucose load (7.4%).

CONCLUSION

Quantification of the variability of a single measure of reproductive hormone levels informs the reliability of reproductive hormone assessment.

The Emerging Therapeutic Potential of Kisspeptin and Neurokinin B

Kisspeptin (KP) and neurokinin B (NKB) are neuropeptides that govern the reproductive endocrine axis through regulating hypothalamic gonadotropin-releasing hormone (GnRH) neuronal activity and pulsatile GnRH secretion. Their critical role in reproductive health was first identified after inactivating variants in genes encoding for KP or NKB signaling were shown to result in congenital hypogonadotropic hypogonadism and a failure of pubertal development. Over the past 2 decades since their discovery, a wealth of evidence from both basic and translational research has laid the foundation for potential therapeutic applications. Beyond KP's function in the hypothalamus, it is also expressed in the placenta, liver, pancreas, adipose tissue, bone, and limbic regions, giving rise to several avenues of research for use in the diagnosis and treatment of pregnancy, metabolic, liver, bone, and behavioral disorders. The role played by NKB in stimulating the hypothalamic thermoregulatory center to mediate menopausal hot flashes has led to the development of medications that antagonize its action as a novel nonsteroidal therapeutic agent for this indication. Furthermore, the ability of NKB antagonism to partially suppress (but not abolish) the reproductive endocrine axis has supported its potential use for the treatment of various reproductive disorders including polycystic ovary syndrome, uterine fibroids, and endometriosis. This review will provide a comprehensive up-to-date overview of the preclinical and clinical data that have paved the way for the development of diagnostic and therapeutic applications of KP and NKB.

Prevalence of functional hypothalamic amenorrhea in a cohort of women referred because of polycystic ovary syndrome

In this unselected population of women referred to a center specialized in gynecologic endocrinology for suspicion of PCOS, a minimum rate of misdiagnosed FHA patients of about 2% was found. It is necessary to evaluate reliable markers for the differential diagnosis between PCOS and FHA to avoid incorrect treatment, which might lead to negative long-term effects in women with undiagnosed FHA.

[Neuroendocrine features of the pathogenesis of polycystic ovary syndrome (literature review)]

Polycystic ovary syndrome (PCOS) is one of the most pressing problems in endocrine gynecology. The main signs of the disease are hyperandrogenism, menstrual and/or ovulatory dysfunction, and polycystic ovarian structure according to ultrasound. Women with PCOS are at risk for developing metabolic syndrome, type 2 diabetes, cardiovascular disease, and endometrial cancer. In this connection, the pathogenetic mechanisms of the occurrence of this syndrome are continuously studied and new methods of treatment are being sought. PCOS is characterized by a wide range of various disorders of the neuroendocrine regulation of the reproductive system. The main focus of the review is aimed at summarizing information about the etiological role of neuropeptides and neurotransmitters, such as phoenixin, galanins, orexins, GABA, in the pathophysiology of PCOS and about the possibility of their use for diagnostic and therapeutic purposes. In recent decades, the interest of scientists has been focused on the study of KNDy neurons, because it is the kisspeptin synthesized by them that is one of the main regulators of the hypothalamic-pituitary-ovarian axis. This article discusses data on the significance of KNDy neurons in the pathogenesis of the syndrome. Information is provided on the effect of elevated levels of androgens and anti-Müllerian hormone on GnRH neurons. Also analyzed are studies on functional and structural disorders in the hypothalamus in PCOS. Literature search was carried out in national (eLibrary, CyberLeninka.ru) and international (PubMed, Cochrane Library) databases in Russian and English. The priority was free access to the full text of articles. The choice of sources was prioritized for the period from 2018 to 2023.However, taking into account the insufficient knowledge of the chosen topic, the choice of sources dates back to 1998.

Anti-Müllerian hormone beyond an ovarian reserve marker: the relationship with the physiology and pathology in the life-long follicle development

Anti-Müllerian hormone (AMH), an indirect indicator of the number of remaining follicles, is clinically used as a test for ovarian reserve. Typically, a decline suggests a decrease in the number of remaining follicles in relation to ovarian toxicity caused by interventions, which may implicate fertility. In contrast, serum AMH levels are elevated in patients with polycystic ovary syndrome. AMH is produced primarily in the granulosa cells of the preantral and small antral follicles. Thus it varies in association with folliculogenesis and the establishment and shrinking of the follicle cohort. Ovarian activity during the female half-life, from the embryonic period to menopause, is based on folliculogenesis and maintenance of the follicle cohort, which is influenced by developmental processes, life events, and interventions. AMH trends over a woman's lifetime are associated with in vivo follicular cohort transitions that cannot be observed directly.

Serum LH levels are associated to serum insulin and Anti-Müllerian hormone levels in women with both functional hypothalamic amenorrhoea and polycystic ovarian morphology

OBJECTIVE

The aim of the study was to investigate whether serum Luteinizing Hormone (LH) levels in women with Functional Hypothalamic Amenorrhoea (FHA) and Polycystic Ovarian Morphology (PCOM) are still associated to Body Mass Index (BMI) and/or serum insulin and/or Anti-Müllerian Hormone (AMH) levels using a larger population of FHA.

DESIGN

Retrospective observational study (2006-2020).

PARTICIPANTS

Data from 62 FHA patients were used for this study using strict criteria to define them.

MEASUREMENTS

Serum LH, FSH, 17-hydroxyprogesterone (17-OHP), dehydroepiandrosterone sulphate (DHEA-S), androstenedione, total testosterone, prolactin, Sex Hormone Binding Globulin (SHBG) and AMH levels were measured by immunoassay. To homogenize the AMH values, we converted those obtained after 2015. We defined PCOM with strict criteria: a follicle number per ovary (FNPO) ≥12 or ≥20 per ovary, depending on the date on which the assessment was carried out and the ultrasound device.

RESULTS

Forty-two percentage of our FHA population had PCOM. The PCOM+ group had significantly higher ranks of BMI (p = .024) and serum AMH levels (p = .0001) and significantly lower ranks of serum FSH levels (p = .002). LH was positively correlated with fasting insulin (p = .011) and with AMH (p = .035) in the PCOM+ group only but not with BMI. There was a positive correlation between LH and FSH in both groups.

CONCLUSION

Our study suggests that GnRH insufficiency in women with PCOM unravels some mechanisms of LH regulation that are poorly documented in the literature and may involve a direct pituitary effect, as suggested by our results with serum insulin and AMH levels.

Endocrine Responses to Triptorelin in Healthy Women, Women With Polycystic Ovary Syndrome, and Women With Hypothalamic Amenorrhea

CONTEXT

Limited data exist regarding whether the endocrine response to the gonadotropin-releasing hormone receptor agonist (GnRHa) triptorelin differs in women with polycystic ovary syndrome (PCOS) compared with healthy women or those with hypothalamic amenorrhea (HA).

OBJECTIVE

We compared the gonadotropin response to triptorelin in healthy women, women with PCOS, or those with HA without ovarian stimulation, and in women with or without polycystic ovaries undergoing oocyte donation cycles after ovarian stimulation.

METHODS

The change in serum gonadotropin levels was determined in (1) a prospective single-blinded placebo-controlled study to determine the endocrine profile of triptorelin (0.2 mg) or saline-placebo in healthy women, women with PCOS, and those with HA, without ovarian stimulation; and (2) a retrospective analysis from a dose-finding randomized controlled trial of triptorelin (0.2-0.4 mg) in oocyte donation cycles after ovarian stimulation.

RESULTS

In Study 1, triptorelin induced an increase in serum luteinizing hormone (LH) of similar amplitude in all women (mean peak LH: healthy, 52.3; PCOS, 46.2; HA, 41.3 IU/L). The AUC of change in serum follicle-stimulating hormone (FSH) was attenuated in women with PCOS compared with healthy women and women with HA (median AUC of change in serum FSH: PCOS, 127.2; healthy, 253.8; HA, 326.7 IU.h/L; P = 0.0005). In Study 2, FSH levels 4 hours after triptorelin were reduced in women with at least one polycystic morphology ovary (n = 60) vs normal morphology ovaries (n = 91) (34.0 vs 42.3 IU/L; P = 0.0003). Serum anti-Müllerian hormone (AMH) was negatively associated with the increase in FSH after triptorelin, both with and without ovarian stimulation.

CONCLUSION

FSH response to triptorelin was attenuated in women with polycystic ovaries, both with and without ovarian stimulation, and was negatively related to AMH levels.

Nourishing Kidney Promoting Ovulation Decoction (NKPOD) Attenuates Polycystic Ovary Syndrome by Downregulating miRNA-224

Background

Currently, exploring effective agents is urgently required for polycystic ovary syndrome (PCOS) treatment. Although nourishing kidney promoting ovulation decoction (NKPOD) as a traditional Chinese medicine decoction is widely employed to increase pregnancy rates, whether NKPOD attenuates ovulation disorders in PCOS patients remains unknown. Here, we aim to explore the clinical significance and the underlying mechanisms of NKPOD in ovulation disorders.

Methods

PCOS patients were recruited to confirm the clinical significance of NKPOD in attenuating ovulation disorder. Subsequently, regulation targets of NKPOD were identified through network pharmacology analysis. Additionally, a series of experiments were performed to observe the impacts of NKPOD on miRNA-224 transcription through transcription factor AR.

Results

In this study, NKPOD administration improved hormone dysregulation and reproductive outcomes in PCOS patients. Interestingly, 100 potential targets related to NKPOD and PCOS were screened, and transcription regulation was observed to be the most enriched function. Mechanistically, NKPOD inhibited miRNA-224 transcription through reducing AR expression, in which AR as a transcription factor directly regulated miRNA-224 transcription.

Conclusions

Collectively, these findings highlight the therapeutic effect of NKPOD on PCOS, which could provide promising therapeutic agents for PCOS.

Sexual functioning in women with functional hypothalamic amenorrhea: exploring the relevance of an underlying polycystic ovary syndrome (PCOS)-phenotype

PURPOSE

To study sexual function and distress in women with functional hypothalamic amenorrhea (FHA) compared to women with FHA and an underlying polycystic ovary syndrome (PCOS)-phenotype, considering also their psychometric variables. As a secondary aim, we explored the relationship between sexual functioning and hormonal milieu in these women.

METHODS

This is a retrospective cross-sectional study conducted on 36 women with typical FHA and 43 women with FHA + PCOS-phenotype. The following validated psychometric questionnaires were administered: Female Sexual Functional Index (FSFI), Female Sexual Distress Scale-Revised (FSDS-R), Body Attitude Test (BAT), Bulimia Investigation Test (BITE), State Anxiety Inventory (STAI), Beck Depression Inventory (BDI), Multidimensional Perfectionism Scale (MPS). Available hormones to formulate FHA diagnosis in the standard routine were considered.

RESULTS

Women with typical FHA reported a significantly lower FSFI total score than women with FHA + PCOS-phenotype (95% CI for median 16-21.3 vs. 21.1-24.1, p = 0.002), whereas the FSDS-R score was similar in the two groups (95% CI for median 6-16 vs. 6-16.3). No statistically significant differences were evident in body attitude, state and trait anxiety, depression, bulimic risk, and perfectionism between the two groups, confirming the two FHA groups were superimposable from a psychometric perspective. State anxiety correlated negatively with the FSFI total score in both typical FHA (rho: - 0.33, p = 0.05) and FHA + PCOS-phenotype (rho: - 0.40, p = 0.009). In the entire study population, a positive correlation was found between luteinizing hormone, androstenedione, and 17ß-estradiol and the total FSFI score (rho: 0.28, p = 0.01; rho: 0.27, p = 0.01, rho: 0.27, p = 0.01, respectively).

CONCLUSION

Women with FHA showed a very high rate of sexual symptoms as part of their condition, but those with a typical diagnosis displayed a more severe sexual impairment as compared with the FHA + PCOS-phenotype, in spite of a similar psychometric profile. Sexual distress was equally present in both groups (approximately 4 out of 10 women). Further studies should be designed to investigate the potential role of sex hormones, mainly LH-driven androstenedione, in influencing women's sexual functioning.

Current pharmacotherapy and future directions for neuroendocrine causes of female infertility

INTRODUCTION

Infertility is recognized as a major global health issue, often associated with significant psychological distress for affected couples. Causes of female infertility include endocrine conditions leading to oligo/anovulation, in addition to structural causes such as tubal, uterine, or peritoneal disorders. Pharmacological treatments, targeting pathways in the hypothalamic-pituitary-ovarian axis, can improve rates of ovulation, conception, pregnancy, and birth. Some existing therapeutic options are hindered by limited efficacy or by a non-physiological mechanism, which can risk excessive stimulation and treatment-related adverse effects. Therefore, there is a continued need for novel therapies to improve care for patients suffering with infertility.

AREAS COVERED

In this review, the authors focus on endocrine causes of oligo/anovulation in women and on advances in assisted reproductive technology. Current pharmacological treatments and putative future therapeutic avenues in development to aid fertility in women are outlined.

EXPERT OPINION

A deeper understanding of the reproductive neuroendocrine network governing hypothalamic gonadotropin-releasing hormone release can offer novel therapeutic targets for the treatment of female subfertility, leading to improved clinical outcomes, less invasive routes of administration, and decreased treatment-related side-effects. The ultimate aim of development in female subfertility is to offer therapeutic interventions that are effective, reproducible, associated with minimal risks, and have an acceptable route of administration.

Hypothalamic-Pituitary-Gonadal Axis Disorders Impacting Fertility in Both Sexes and the Potential of Kisspeptin-Based Therapies to Treat Them

Impaired function of the hypothalamic-pituitary-gonadal (HPG) axis can lead to a vast array of reproductive disorders some of which are inherited or acquired, but many are of unknown etiology. Among the clinical consequences of HPG impairment, infertility is quite common. According to the latest report from the World Health Organization, the global prevalence of infertility during a person's lifetime is a staggering 17.5% which translate into 1 out of every 6 people experiencing it. In both sexes, infertility is associated with adverse health events, and if unresolved, infertility can cause substantial psychological stress, social stigmatization, and economic strain. Even though significant advances have been made in the management and treatment of infertility, low or variable efficacy of treatments and medication adverse effects still pose a significant problem. However, the discovery that in humans inactivating mutations in the gene encoding the kisspeptin receptor (Kiss1R) results in pubertal failure and infertility has expanded our understanding of the mechanisms underlying the neuroendocrine control of reproduction, opening up potential new therapies for the treatment of infertility disorders. In this chapter we provide an overview of common infertility disorders affecting men and women, their recommended treatments, and the potential of kisspeptin-based pharmacotherapies to treat them.

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.

The Effect of Leptin on the Blood Hormonal Profile (Cortisol, Insulin, Thyroid Hormones) of the Ewe in Acute Inflammation in Two Different Photoperiodical Conditions

As a day animal with sensitivity to inflammation similar to that of humans, the sheep may highly outperform the rodent model in inflammation studies. Additionally, seasonality makes sheep an interesting model in endocrinology research. Although there are studies concerning inflammation’s influence on leptin secretion and vice versa, a ewe model, with its possible ‘long-day leptin resistance’, is still not examined enough. The present study aimed to examine whether leptin may modulate an acute inflammation influence on plasma hormones in two photoperiodical conditions. The experiment was conducted on 48 ewes divided into four groups (control, lipopolysaccharide (LPS), leptin, LPS + leptin) during short and long days. Blood sampling started 1 hour before and continued 3 h after LPS/saline administration for further hormonal analysis. The results showed that the photoperiod is one of the main factors influencing the basal concentrations of several hormones with higher values of leptin, insulin and thyroid hormones during long days. Additionally, the acute inflammation effect on cortisol, insulin and thyroid hormones was photoperiod-dependent. The endotoxemia may also exert an influence on leptin concentration regardless of season. The effects of leptin alone on hormone blood concentrations are rather limited; however, leptin can modulate the LPS influence on insulin or thyroxine in a photoperiod-dependent way.

Comparative study of DHEA and letrozole induced polycystic ovary syndrome in post-pubertal rats

AIM

In order to select a suitable rat model for studying polycystic ovary syndrome (PCOS).

METHODS

Post-pubertal Sprague Dawley (SD) rats were allocated to four groups, abbreviated as the control 1 group, DHEA subcutaneous injection (DHEA) group, control 2 group, letrozole intragastric injection (letrozole) group. Body weight and the estrous cycle were monitored during the modeling. Serum stress hormones and reproductive hormones were evaluated by ELISA. The uterus and ovaries were weighed, ovarian follicle counts were calculated, and AR, LHR, FSHR, and AMH expression were assessed by immunohistochemistry.

RESULTS

In both model group subjected to the 30-day protocol of DHEA or letrozole, the mean body weights were significantly increased. Rats from both model group exhibited a significant increase of the mean length of the diestrous phase of the estrous cycle, the DHEA group had a longer diestrous phase. There was also a significant increase of serum T, E2, LH, insulin, and a significant decrease of AMH in both model group. There was a significant decrease of ovarian weight, P, and serum FSH, and a significant increase of uterus weight, serum LH/FSH in DHEA model group. There was no significant difference in serum P, FSH, and LH/FSH in letrozole model group. Both two model groups showed significantly higher AR, LHR, and AMH protein expression in rats' ovaries. FSHR protein expression in DHEA group was lower, and in letrozole model group was not different.

CONCLUSION

Compared with letrozole intragastric injection group, the pathological characteristics of DHEA subcutaneous injection group rats were closer to the characteristics of PCOS.

Neuroendocrine Determinants of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women and a major cause of anovulatory infertility. A diagnosis of PCOS is established based the presence of two out of three clinical symptoms, which are criteria accepted by the ESHRE/ASRM (European Society of Human Reproduction and Embryology/American Society for Reproductive Medicine). Gonadotropin-releasing hormone (GnRH) is responsible for the release of luteinizing hormone, and follicle stimulating hormone from the pituitary and contributes a leading role in controlling reproductive function in humans. The goal of this review is to present the current knowledge on neuroendocrine determinations of PCOS. The role of such neurohormones as GnRH, and neuropeptides kisspeptin, neurokinin B, phoenixin-14, and galanin is discussed in this aspect. Additionally, different neurotransmitters (gamma-aminobutyric acid (GABA), glutamate, serotonin, dopamine, and acetylcholine) can also be involved in neuroendocrine etiopathogenesis of PCOS. Studies have shown a persistent rapid GnRH pulse frequency in women with PCOS present during the whole ovulatory cycle. Other studies have proved that patients with PCOS are characterized by higher serum kisspeptin levels. The observations of elevated serum kisspeptin levels in PCOS correspond with the hypothesis that overactivity in the kisspeptin system is responsible for hypothalamic-pituitary-gonadal axis overactivity. In turn, this causes menstrual disorders, hyperandrogenemia and hyperandrogenism. Moreover, abnormal regulation of Neurokinin B (NKB) is also suspected of contributing to PCOS development, while NKB antagonists are used in the treatment of PCOS leading to reduction in Luteinizing hormone (LH) concentration and total testosterone concentration. GnRH secretion is regulated not only by kisspeptin and neurokinin B, but also by other neurohormones, such as phoenixin-14, galanin, and Glucagon-like peptide-1 (GLP-1), that have favorable effects in counteracting the progress of PCOS. A similar process is associated with the neurotransmitters such as GABA, glutamate, serotonin, dopamine, and acetylcholine, as well as the opioid system, which may interfere with secretion of GnRH, and therefore, influence the development and severity of symptoms in PCOS patients. Additional studies are required to explain entire, real mechanisms responsible for PCOS neuroendocrine background.

Insulin-like peptide 3 in domestic animals with normal and abnormal reproductive functions, in comparison to rodents and humans

Background

Insulin-like peptide 3 (INSL3) is a circulating hormone secreted from only testis and ovaries in mammals. Findings on INSL3 have been gathered from subjects with normal and abnormal reproductive statuses, especially rodents and humans. However, little to no review articles focusing on INSL3 in domestic animals exist.

Methods

The author reviewed the past and recent literature regarding the structure, expression, roles of INSL3 in the reproductive organs, and its circulation under normal and aberrant reproductive conditions in domestic animals in comparison with rodents and humans.

Main findings

As with humans and rodents, blood INSL3 concentrations rise around puberty in normal male domestic animals and are associated with testicular size. INSL3 levels are acutely upregulated by luteinizing hormone (LH), and the increase is smaller than that of testosterone in male ruminants, whereas the acute regulation of INSL3 by LH does not occur in human men. Dogs with cryptorchidism and bulls with abnormal semen have lowered INSL3 levels.

Conclusion

The findings regarding INSL3 secretions in male domestic animals with normal and aberrant reproductive functions illustrate similar or dissimilar points to humans and rodents. Data on blood INSL3 levels in normal and abnormal female domestic species are still limited and require further investigation.

Kisspeptin-neuron control of LH pulsatility and ovulation

Feedback from oestradiol (E2) plays a critical role in the regulation of major events in the physiological menstrual cycle including the release of gonadotrophins to stimulate follicular growth, and the mid-cycle luteinising hormone (LH) surge that leads to ovulation. E2 predominantly exerts its action via oestrogen receptor-alpha (ERα), however, as gonadotrophin releasing hormone (GnRH) neurons lack ERα, E2-feedback is posited to be indirectly mediated via upstream neurons. Kisspeptin (KP) is a neuropeptide expressed in hypothalamic KP-neurons that control GnRH secretion and plays a key role in the central mechanism regulating the hypothalamic-pituitary-gonadal (HPG) axis. In the rodent arcuate (ARC) nucleus, KP is co-expressed with Neurokinin B and Dynorphin; and thus, these neurons are termed 'Kisspeptin-Neurokinin B-Dynorphin' (KNDy) neurons. ARC KP-neurons function as the 'GnRH pulse generator' to regulate GnRH pulsatility, as well as mediating negative feedback from E2. A second KP neuronal population is present in the rostral periventricular area of the third ventricle (RP3V), which includes anteroventral periventricular (AVPV) nucleus and preoptic area neurons. These RP3V KP-neurons mediate positive feedback to induce the mid-cycle luteinising hormone (LH) surge and subsequent ovulation. Here, we describe the role of KP-neurons in these two regions in mediating this differential feedback from oestrogens. We conclude by considering reproductive diseases for which exploitation of these mechanisms could yield future therapies.

Polycystic Ovary Syndrome Phenotype D Versus Functional Hypothalamic Amenorrhea With Polycystic Ovarian Morphology: A Retrospective Study About a Frequent Differential Diagnosis

The two most frequent causes of secondary amenorrhea are polycystic ovary syndrome (PCOS) and functional hypothalamic amenorrhea (FHA). Despite several studies showing differences in hormonal profile between these groups, the differential diagnosis remains challenging, in particular between FHA women with polycystic ovarian morphology (FHA-PCOM) and PCOS patients without hyperandrogenism (phenotype D, PCOS-D). In a retrospective case-control study, 58 clearly defined patients with FHA-PCOM were compared to 58 PCOS-D patients, matched 1:1 for age and BMI. Significantly higher levels of LH, estradiol, testosterone, and a higher luteinizing hormone (LH): follicle stimulating hormone (FSH) ratio as well as lower sexual hormone binding globulin (SHBG) levels were found in PCOS-D patients (p< 0.05). Optimized cut-off values for the prediction of FHA-PCOM were calculated by the Youden index. The highest sensitivity was found for an estradiol serum level <37.5 pg/mL (84.5%, 95% confidence interval, CI: 72.6-92.6), whereas a LH : FSH ratio <0.96 had the highest specificity (94.8, 95% CI: 85.6-98.9). A linear discriminant analysis including testosterone, SHBG and LH was able to correctly classify 87.9% of FHA-PCOM patients (bootstrap 95% CI: 80.2 - 94.0%). In conclusion, this model including serological parameters could be an easy and reliable tool to distinguish between FHA-PCOM and PCOS-D patients, especially in situations where the clinical profile is not obvious.

Impact on ovarian reserve after minimally invasive single-port laparoscopic ovarian cystectomy in patients with benign ovarian cysts: A systematic review and meta-analysis

BACKGROUND/AIM

The purpose of this article is to review the published literature on single-port laparoscopic (SPL) ovarian cystectomy and to assess whether the reduced port number affects the ovarian reserve in comparison with the conventional multiport laparoscopic (MPL) ovarian cystectomy.

MATERIALS AND METHODS

It has been suggested that the most accurate marker of ovarian reserve is the Serum anti-Müllerian hormone (AMH). A review of the current literature was performed based on the preoperative and postoperative AMH after SPL and MPL ovarian cystectomy in adult patients with benign ovarian cysts.

RESULTS

Ovarian cystectomy causes a non-statistically significant reduction in AMH levels four weeks postoperatively in the SPL group compared to the MPL group [MD = 0.11, 95% CI (-0.01, 0.24), P =0 .07]. Operative time was significantly longer, and blood loss was significantly higher in the SPL group. No difference was reported in terms of major or overall postoperative complications between the two groups.

CONCLUSION

SPL cystectomy may be offered as a minimally invasive surgical alternative for patients who want to preserve their fertility, at the cost of higher blood loss and longer operative time.