Insight on the Intracrinology of Menopause: Androgen Production within the Human Vagina

Counseling Women About Sexual Health Effects of Contraceptives

Background: Choosing a contraceptive method is a pivotal decision for patients, whereas health care professionals (HCPs) face challenges in providing suitable recommendations. Adverse sexual effects often lead to dissatisfaction and discontinuation of contraceptives, underscoring the importance of thorough counseling and shared decision making between HCPs and patients. Objective: This article aims to investigate the relationship between contraceptive methods and female sexual function through a comprehensive review of available literature, emphasizing the importance of considering sexual health in contraceptive prescription and management. Methods: A systematic analysis of existing literature, incorporating studies utilizing validated sexual health questionnaires, was conducted to elucidate the intricate interplay between contraceptives and female sexual function. Results: The review encompasses various contraceptive methods, including combined hormonal contraceptives, progestin-only pills, depot medroxyprogesterone acetate, subdermal contraceptive implants, hormonal intrauterine devices, permanent sterilization, and barrier methods. Insights gleaned from the analysis shed light on the impact of these methods on female sexual health. Conclusion: Comprehensive understanding of the effects of contraceptives on female sexual function is crucial for both HCPs and patients. By integrating sexual health considerations into contraceptive surveillance, compliance can be improved, contraceptive efficacy optimized, and the risk of unwanted pregnancies minimized. This review underscores the significance of tailored counseling and shared decision making in contraceptive management, particularly for cisgender women.

Genitourinary syndrome of lactation: a new perspective on postpartum and lactation-related genitourinary symptoms

BACKGROUND

The genitourinary syndrome of menopause (GSM) is a well-documented condition characterized by a range of genitourinary symptoms in peri- and postmenopausal women. As with GSM, postpartum lactating women experience reduced estrogen and androgen levels. However, there is limited research on the impact of symptoms during the postpartum breastfeeding period.

OBJECTIVES

The aim was to review the literature for genitourinary health in the postpartum breastfeeding population and summarize key findings and potential treatments.

METHODS

We performed a comprehensive literature review in PubMed, Google Scholar, and Scopus from inception of database to November 2023 using the following keywords individually and in combination: "physiology of postpartum" or "physiology of lactogenesis" or "vulvovaginal health" or "vaginal atrophy" or "vaginal dryness" or "dyspareunia" or "urinary incontinence" or "lactation" or "breastfeeding" or "vaginal estrogen." All identified articles published in English were considered. Relevant studies were extracted, evaluated, and analyzed. The work presented in this article represents a summative review of the identified literature.

RESULTS

During lactation, high levels of prolactin inhibit estrogen and androgen secretion via negative feedback, which leads to an increased prevalence of vulvovaginal atrophy, vaginal dryness, dyspareunia, and urinary incontinence in lactating postpartum women. Despite these highly prevalent and potentially devastating symptoms, there is a lack of consistent screening at postpartum visits and no treatment guidelines available to health care providers.

CONCLUSION

Postpartum breastfeeding women experience similar physiology and symptoms to the postmenopausal phase, as seen in GSM. We propose the introduction of a novel term to describe the genitourinary changes seen in postpartum breastfeeding individuals: genitourinary syndrome of lactation. The diagnostic use of genitourinary syndrome of lactation will equip health care providers with an all-encompassing term to bring awareness to the symptoms experienced by postpartum breastfeeding individuals and lead to improved screening and treatment for the high numbers of individuals experiencing these genitourinary changes.

Development and validation of the genitourinary syndrome of menopause symptoms and vaginal treatments acceptability questionnaire (GSM-SVTAQ): An electronic patient-reported outcomes measure

OBJECTIVES

To develop and validate an electronic, patient-reported outcomes measure (PROM) specific for genitourinary syndrome of menopause (GSM) patients. The PROM aimed to accurately assess the burden of GSM symptoms, their impact on health-related and sexual quality of life, and the acceptability of vaginal treatments.

METHODS

The study encompassed a comprehensive three-stage approach to the development and validation of the PROM. Initially, during the preliminary design stage, the necessity for a new PROM was recognized, an expert panel was formed, and semi-structured qualitative interviews were carried out with GSM patients. In the second stage, the study used the five-step pre-validation methodology established by Prior et al. to generate and refine the PROM items. The third and final stage encompassed the determination of scale and item content validity indexes to ensure validity. Additionally, the reliability of each construct was evaluated using Cronbach's α.

RESULTS

The resulting PROM was named GSM-SVTAQ (GSM-symptoms and vaginal treatments acceptability questionnaire). It demonstrated excellent validity in assessing symptoms burden, health-related and sexual quality of life, and vaginal treatment acceptability, with high content validity indices and strong internal consistency. The scale content validity indices and Cronbach's α coefficients for the three domains were (0.926, 0.939), (0.875, 0.947), and (0.824, 0.855), respectively.

CONCLUSION

The GSM-SVTAQ stands as the first GSM-specific, valid, and reliable PROM capable of comprehensively measuring the three components of GSM and the acceptability of vaginal treatments. Its implementation has the potential to significantly enhance patient care and outcomes in GSM management.

Therapeutic Effects of Vitamin D on Vaginal, Sexual, and Urological Functions in Postmenopausal Women

Recent years have witnessed the emergence of growing evidence concerning vitamin D's potential role in women's health, specifically in postmenopausal women. This evidence also includes its connection to various genitourinary disorders and symptoms. Numerous clinical studies have observed improvements in vulvovaginal symptoms linked to the genitourinary syndrome of menopause (GSM) with vitamin D supplementation. These studies have reported positive effects on various aspects, such as vaginal pH, dryness, sexual functioning, reduced libido, and decreased urinary tract infections. Many mechanisms underlying these pharmacological effects have since been proposed. Vitamin D receptors (VDRs) have been identified as a major contributor to its effects. It is now well known that VDRs are expressed in the superficial layers of the urogenital organs. Additionally, vitamin D plays a crucial role in supporting immune function and modulating the body's defense mechanisms. However, the characterization of these effects requires more investigation. Reviewing existing evidence regarding vitamin D's impact on postmenopausal women's vaginal, sexual, and urological health is the purpose of this article. As research in this area continues, there is a potential for vitamin D to support women's urogenital and sexual health during the menopausal transition and postmenopausal periods.

Endometrial safety of low-dose vaginal estrogens

ABSTRACT

It is estimated that up to 50% to 90% of postmenopausal women may experience genitourinary syndrome of menopause (GSM), which may have a detrimental impact on quality of life. One of the most effective modes of treatment of GSM is low-dose vaginal estrogens. Numerous studies have addressed the safety of these estrogens using endometrial biopsy and/or endometrial thickness on ultrasound. Based on these studies, the consensus is that low-dose vaginal estrogens do not substantially increase the risk of endometrial hyperplasia or cancer; however, the data are severely limited by short duration of follow-up. Although long-term trials are warranted, they are difficult to carry out, costly, and will not yield data for years. More immediate information regarding endometrial safety may be obtained from studies measuring endometrial tissue and serum concentrations of estradiol, estrone, and relevant equine estrogens after administration of different estrogen formulations and doses. This would allow us to understand better the metabolism of estrogens by the vagina and endometrium, and how much estrogen is reaching the endometrium. Here, we discuss metabolism, receptor binding, and signaling of estrogens in vaginal and endometrial tissue, and summarize the existing studies on the endometrial impact of low-dose vaginal estrogen treatment in postmenopausal women.

Androgens in endometrial carcinoma: the killer or helper?

PURPOSE

The aim of this review is to discuss the role of androgens in the progression of endometrial carcinoma (EC) with particular focus on the different kinds of androgenic hormones, androgen receptor (AR) and intracrine androgen metabolism.

METHODS

A comprehensive literature search within PubMed was performed. Selected publications related to androgens and EC were reviewed.

RESULTS

There are different kinds of androgenic hormones, and different kinds of androgens may have different effects. Elevated androgens (especially testosterone) have been associated with an increased EC risk in postmenopausal women. 5α-reductases (5α-Reds) and 17β-hydroxysteroid dehydrogenase type 2 (17βHSD2) pathway may inhibit the progression of EC mediated by dihydrotestosterone (DHT), but aromatases stimulate further progression of EC. The most of studies accessing the prognostic value of AR have found that AR expression may be a favorable prognostic indicator.

CONCLUSION

Androgens may have both oncogenic and tumor suppressive roles. Androgen-specific biases in metabolism and the expression of AR may contribute to the different prognosis of patients with EC.

The regulatory effect of sex steroids on the RhoA/ROCK pathway in the rat distal vagina

BACKGROUND

Sex steroids have been demonstrated as important modulators of vaginal function. The RhoA/ROCK calcium-sensitizing pathway plays a role in genital smooth muscle contractile mechanism, but its regulation has never been elucidated.

AIM

This study investigated the sex steroid regulation of the vaginal smooth muscle RhoA/ROCK pathway using a validated animal model.

METHODS

Ovariectomized (OVX) Sprague-Dawley rats were treated with 17β-estradiol (E2), testosterone (T), and T with letrozole (T + L) and compared with intact animals. Contractility studies were performed to test the effect of the ROCK inhibitor Y-27632 and the nitric oxide (NO) synthase inhibitor L-NAME. In vaginal tissues, ROCK1 immunolocalization was investigated; mRNA expression was analyzed by semiquantitative reverse transcriptase-polymerase chain reaction; and RhoA membrane translocation was evaluated by Western blot. Finally, rat vaginal smooth muscle cells (rvSMCs) were isolated from the distal vagina of intact and OVX animals, and quantification of the RhoA inhibitory protein RhoGDI was performed after stimulation with NO donor sodium nitroprusside, with or without administration of the soluble guanylate cyclase inhibitor ODQ or PRKG1 inhibitor KT5823.

OUTCOMES

Androgens are critical in inhibiting the RhoA/ROCK pathway of the smooth muscle compartment in the distal vagina.

RESULTS

ROCK1 was immunolocalized in the smooth muscle bundles and blood vessel wall of the vagina, with weak positivity detected in the epithelium. Y-27632 induced a dose-dependent relaxation of noradrenaline precontracted vaginal strips, decreased by OVX and restored by E2, while T and T + L decreased it below the OVX level. In Western blot analysis, when compared with control, OVX significantly induced RhoA activation, as revealed by its membrane translocation, with T reverting it at a level significantly lower than in controls. This effect was not exerted by E2. Abolishing NO formation via L-NAME increased Y-27632 responsiveness in the OVX + T group; L-NAME had partial effects in controls while not modulating Y-27632 responsiveness in the OVX and OVX + E2 groups. Finally, stimulation of rvSMCs from control animals with sodium nitroprusside significantly increased RhoGDI protein expression, counteracted by ODQ and partially by KT5823 incubation; no effect was observed in rvSMCs from OVX rats.

CLINICAL IMPLICATIONS

Androgens, by inhibiting the RhoA/ROCK pathway, could positively contribute to vaginal smooth muscle relaxation, favoring sexual intercourse.

STRENGTHS AND LIMITATIONS

This study describes the role of androgens in maintaining vaginal well-being. The absence of a sham-operated animal group and the use of the only intact animal as control represented a limitation to the study.

Revisiting the physiological role of androgens in women

INTRODUCTION

Extensive research underlines the critical functions of androgens in females. Nevertheless, the precise mechanisms of their action are poorly understood. Here, we review the existing literature regarding the physiological role of androgens in women throughout life.

AREAS COVERED

Several studies show that androgen receptors (ARs) are broadly expressed in numerous female tissues. They are essential for many physiological processes, including reproductive, sexual, cardiovascular, bone, muscle, and brain health. They are also involved in adipose tissue and liver function. Androgen levels change with the menstrual cycle and decrease in the first decades of life, independently of menopause.

EXPERT OPINION

To date, studies are limited by including small numbers of women, the difficulty of dosing androgens, and their cyclical variations. In particular, whether androgens play any significant role in regulating the establishment of pregnancy is poorly understood. The neural functions of ARs have also been investigated less thoroughly, although it is expressed at high levels in brain structures. Moreover, the mechanism underlying the decline of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) with age is unclear. Other factors, including estrogen's effect on adrenal androgen production, reciprocal regulation of ARs, and non-classical effects of androgens, remain to be determined.

Excess dietary zinc drives a Cushing's-like syndrome in ovariectomized mice - Implications for postmenopausal obesity

Postmenopausal women have an increased risk of obesity, but the underlying cause is not clear. We unexpectedly found that excess dietary zinc induced severe obesity and a Cushing's-like syndrome without increased food intake in ovariectomized (Ovx) but not in sham-operated mice. Zinc accumulated in the adrenal glands and inhibited adrenal 17,20-lyase activity and steroid synthesis. As adrenal steroids are the only source of estrogen in Ovx mice, estrogen deficiency induced adrenal hyperplasia, glucocorticoid overproduction, and consequent development of a Cushing's-like syndrome. Adrenal steroid supplementation prevented the effects of zinc. Plasma zinc was positively correlated with cortisol level and negatively correlated with the levels of adrenal steroids and estrogen in obese postmenopausal women. The finding of a link between dietary zinc, estrogen deficiency, and postmenopausal obesity, implies that postmenopausal obesity might be prevented by supplementation with a adrenal steroid and avoiding excess dietary zinc.

Testosterone positively regulates vagina NO-induced relaxation: an experimental study in rats

PURPOSE

Female sexual response involves a complex interplay between neurophysiological mechanisms and the nitric oxide (NO)-mediated relaxation of clitoris and vagina. The aim of this study was to evaluate sex steroids regulation of the relaxant pathway in vagina, using a validated animal model.

METHODS

Subgroups of OVX Sprague-Dawley rats were treated with 17β-estradiol, testosterone, or testosterone and letrozole, and compared with a group of intact animals. Masson's trichrome staining was performed for morphological evaluation of the distal vaginal wall, in vitro contractility studies investigated the effect of OVX and in vivo treatments on vaginal smooth muscle activity. RNA from vaginal tissue was analyzed by semi-quantitative RT-PCR.

RESULTS

Immunohistochemical analysis showed that OVX induced epithelial and smooth muscle structural atrophy, testosterone and testo + letrozole increased the muscle bundles content and organization without affecting the epithelium while 17β-estradiol mediated the opposite effects. In vitro contractility studies were performed on noradrenaline pre-contracted vaginal strips from each experimental group. Acetylcholine (0.001-10 µM) stimulation induced a concentration-dependent relaxation, significantly reduced by NO-synthase inhibitor L-NAME and by guanylate cyclase inhibitor ODQ. OVX resulted in a decreased responsiveness to acetylcholine, restored by testosterone, with or without letrozole, but not by 17β-estradiol. OVX sensitivity to the NO-donor SNP was higher than in the control. Vardenafil, a PDE5 inhibitor, enhanced SNP effect in OVX + testosterone as well as in control, as supported by RNA expression analysis.

CONCLUSIONS

Our study demonstrates that testosterone improves the NO-mediated smooth muscle vaginal cells relaxation confirming its role in maintaining the integrity of muscular relaxant machinery.

Safety of prasterone in breast cancer survivors treated with aromatase inhibitors: the VIBRA pilot study

BACKGROUND

Due to safety concerns on estrogen-based treatments for genitourinary syndrome of menopause (GSM) in breast cancer survivors (BCS), new options are appearing, such as androgen-based treatments, which according to proprieties would not be transformed systemically to estrogens in patients receiving aromatase inhibitors (AIs).

OBJECTIVE

The aim of this pilot study is to assess the security and efficacy of vaginal prasterone (dehydroepiandrostenedione [DHEA]) in BCS treated with AIs.

METHODS

This open, prospective, pilot study included 10 BCS treated with AIs. All participants complained of severe GSM. DHEA was administrated as a vaginal ovule. Participants were instructed to use one ovule every night during the first month, and one ovule every two nights for the entire five remaining months. The patients were requested to attend seriated visits after the beginning of the prasterone treatment to evaluate symptoms, physical improvement and serum estradiol.

RESULTS

Mean serum estradiol remained low from 3.4 pg/ml to 4.3 pg/ml (p = 0.9136) after 6 months of follow-up. The visual analog scale of dyspareunia improved from 8.5 to mean values after treatment of 0.4 (p = 0.0178). The Vaginal Health Index (VHI) scale and Female Sexual Function Index improved from 9.75 to 15.8 (p = 0.0277) and from an initial score of 11.2 to 20.6 (p = 0.0277), respectively. Vaginal pH changed from basal 8.1 to final 6.5 (p = 0.0330).

CONCLUSION

Symptoms and physical examination regarding sexuality and vaginal health improved significantly, while serum estradiol remained at low levels. Prasterone seems a safe and effective option to treat GSM in BCS receiving AIs.

Female Reproductive Systems: Hormone Dependence and Receptor Expression

The female reproductive system which consists of the ovaries, uterus (myometrium, endometrium), Fallopian tubes, cervix and vagina is exquisitely sensitive to the actions of steroid hormones. The ovaries play a key role in the synthesis of bioactive steroids (oestrogens, androgens, progestins) that act both within the tissue (intracrine/paracrine) as well as on other reproductive organs following release into the blood stream (endocrine action). Sex steroid receptors encoded by the oestrogen (ESR1, ESR2), progesterone (PR) and androgen (AR) receptor genes, which are members of the superfamily of ligand activated transcription factors are widely expressed within these tissues. These receptors play critical role(s) in regulation of cell proliferation, ovulation, endometrial receptivity, myometrial cell function and inflammatory cell infiltration. Our understanding of their importance has been informed by studies on human tissues and cells, which have employed immunohistochemistry as well as a wide range of molecular and genetic methods to identify which processes are dependent steroid ligand activation. The development of mice with targeted deletions of each of these receptors has provided complementary data that has extended our appreciation of cell-cell interactions in the fine tuning of reproductive tissue function. This large body of work has formed the basis of new and improved therapeutics to treat conditions such as infertility.

Effect of Zinc on Testosterone Levels and Sexual Function of Postmenopausal Women: A Randomized Controlled Trial

This study aimed to investigate the effect of zinc supplementation on testosterone levels and sexual function in postmenopausal women. This randomized clinical trial was performed on 116 postmenopausal women with serum zinc levels below 62, and low sexual function who were randomly divided into two groups: intervention and control. Serum zinc levels, testosterone, hemoglobin and hematocrit, as well as their Female Sexual Function Index (FSFI) were evaluated before and after the intervention. Data analysis was performed using paired and independent t-tests, Fisher's exact test, and Chi Square test. The use of zinc supplementation in the intervention group significantly improved sexual desire, arousal, orgasm, satisfaction, vaginal moisture, and pain during intercourse and also the overall score of sexual function compared to the control group (p < 0.001). Zinc supplementation in the intervention group, resulted in a significant increase in testosterone levels compared to the control group, which improved sexual function in postmenopausal women non-significantly. The results of this study showed that zinc supplementation can improve testosterone levels and sexual function in postmenopausal women. Using this supplement in postmenopausal women having zinc insufficiency is recommended. Also, there is need for more studies to prove the effect of zinc on testosterone and sexual function.