The Influence of Testosterone Combined with a PDE5-inhibitor on Cognitive, Affective, and Physiological Sexual Functioning in Women Suffering from Sexual Dysfunction

The elusive concept of sexual motivation: can it be anchored in the nervous system?

Sexual motivation is an abstract concept referring to the mechanisms determining the responsivity to sexually relevant stimuli. This responsivity determines the likelihood of producing a sexual response and the intensity of that response. Both responsivity to stimuli and the likelihood of making a response as well as the intensity of response are characteristics of an individual. Therefore, we need to assume that the concept of sexual motivation materializes in physiological mechanisms within the individual. The aim of the present communication is to analyze the requisites for the endeavor to materialize sexual motivation. The first requisite is to provide an operational definition, making the concept quantifiable. We show that parameters of copulatory behavior are inappropriate. We argue that the intensity of sexual approach behaviors provides the best estimate of sexual motivation in non-human animals, whereas the magnitude of genital responses is an exquisite indicator of human sexual motivation. Having assured how to quantify sexual motivation, we can then proceed to the search for physiological or neurobiological underpinnings. In fact, sexual motivation only manifests itself in animals exposed to appropriate amounts of gonadal hormones. In female rats, the estrogen receptor α in the ventrolateral part of the ventromedial nucleus of the hypothalamus is necessary for the expression of sexual approach behaviors. In male rats, androgen receptors within the medial preoptic area are crucial. Thus, in rats sexual motivation can be localized to specific brain structures, and even to specific cells within these structures. In humans, it is not even known if sexual motivation is materialized in the brain or in peripheral structures. Substantial efforts have been made to determine the relationship between the activity of neurotransmitters and the intensity of sexual motivation, particularly in rodents. The results of this effort have been meager. Likewise, efforts of finding drugs to stimulate sexual motivation, particularly in women complaining of low sexual desire, have produced dismal results. In sum, it appears that the abstract concept of sexual motivation can be reliably quantified, and the neurobiological bases can be described in non-human animals. In humans, objective quantification is feasible, but the neurobiological substrate remains enigmatic.

The Dual Control Model of Sexual Response: A Scoping Review, 2009-2022

The Dual Control Model proposes that sexual arousal and related processes are dependent on the balance between sexual excitation and sexual inhibition, and that individuals vary in their propensity for these processes. This scoping review provides an overview and discussion of the questionnaires used to measure the propensities for sexual excitation and inhibition, their translation and validation in other languages, and their application in empirical research on topics ranging from sexual desire and arousal, sexual (dys)function, sexual risk taking, asexuality, hypersexuality, and sexual aggression. A total of 152 papers, published between 2009 and 2022 and identified using online databases, were included in this review. The findings, consistent with those reviewed by Bancroft et al. (2009), suggest that sexual excitation is particularly relevant to sexual desire and responsivity and predictive of asexuality and hypersexuality. Sexual inhibition plays a role in sexual dysfunction. sexual risk taking, and sexual aggression, although often in interaction with sexual excitation. Suggestions for the further development of the model and for future studies are discussed.

Treatment of Sexual Dysfunction in Women with Systemic Autoimmune Rheumatic Disorders: A Systematic Review

Introduction

Female sexual dysfunction (SD) is an under-recognized and undertreated problem in patients with systemic autoimmune rheumatic disorders (SARDs).

Objectives

To summarize and evaluate the existing treatment modalities for SD in females with SARDs.

Methods

A systematic review was conducted following the PRISMA guidelines. Electronic databases were searched up to April 2022 for studies that assessed the use of pharmacological and non-pharmacological treatment modalities for the management of SD in females with SARDs. Randomized and observational studies were included. (PROSPERO: CRD42022296381).

Results

Seven studies with 426 females with SD were included. Seven different treatment modalities belonging to 5 different classes (androgen therapy, phosphodiesterase-5 inhibitors, exercise, education and local creams) were evaluated in patients with systemic lupus erythematosus, rheumatoid arthritis and systemic sclerosis. The majority of the studies were of low methodological quality. Standardized patient education and 8-week aerobic walking programs were successful in improving female SD. Local creams improved dyspareunia in females with systemic sclerosis. Testosterone did not significantly improve SD in patients with systemic lupus erythematosus. Accordingly, tadalafil did not result in a significant improvement of SD in females with systemic sclerosis, based on the Female Sexual Function Index.

Conclusion

There is a lack of sufficient evidence to recommend a certain management strategy for SD in females with SARDs. Nonpharmacological therapy and lubricant creams may be beneficial in females with SARDs. No benefit was demonstrated after androgen therapy or tadalafil. Still, no definite conclusions can be drawn due to the important limitations of the available literature. Overall, our results may be considered preliminary and further research in the field is mandatory.

Introducing sexual dysfunction in mental care

Introduction: People with any psychiatric disorder tend to have difficulties in responding sexually. However,sexual dysfunction (SD) is usually under-recognized, even the tightly hormonal and neuronal common connexions through the brain-sex axis. Multiple sources of resistance to SD assessment and intervention persist. Areas covered: The present review aims to underline the feasibility to introduce SD evaluation in patients with any psychiatric disorders, evaluating the potential mutual benefits of their management. Expert opinion: Women and men living with mental disorders frequently display sexual difficulties; however, some of them consider sexuality as a relevant parameter of their quality of life. In fact, SD as a side effect is a frequent reason for stopping the intake of medication. What is more, a holistic approach integrating sexual function could foster a better understanding of mental pathologies due to a common origin of pathogenesis. This could improve care quality, in keeping with the global tendency toward the development of personalized medicine. Consistently, the integration of SD assessment is highly recommended in mental health, all the more so when a psychotropic drug is prescribed. An expected consequence would be a reconstruction of the healthcare professional's consideration for the sexuality of people experiencing mental disorders.

Testosterone therapy and other treatment modalities for female sexual dysfunction

PURPOSE OF REVIEW

Recently in October 2019 a Global Consensus Position on the use of Testosterone Therapy for Women was published. The use of testosterone and other agents for female sexual dysfunction (FSD) is an important topic for the urologist focusing on sexual health. This review describes the known causes for FSD, and discusses the role of androgens in this disorder, the evidence for using testosterone treatment, and other current and emerging therapies.

RECENT FINDINGS

A recent meta-analysis, published in The Lancet Diabetes & Endocrinology evaluated a total of 36 randomized control trials spanning 1990-2018 and includes a total of 8480 patients. The primary findings were that testosterone therapy (TTh) increased sexual function including satisfactory sexual event frequency, sexual desire, pleasure, arousal, orgasm, responsiveness, and self-image when compared with either a placebo or drug-control (e.g., estrogen ± progestogen). In addition, TTh reduced sexual concerns and distress in postmenopausal women. Side effects included an increase in weight, acne, and hair growth, but there was no increase in serious adverse events. Importantly, TTh duration was greater than 12 weeks in all randomized control trials included in this meta-analysis.

SUMMARY

TTh is effective to treat FSD in postmenopausal women. More data is required to evaluate the long-term safety data on the effects of TTh on cardiovascular health, breast health, cognitive function, and the musculoskeletal system in women.

Understanding sexual arousal and subjective-genital arousal desynchrony in women

Sexual arousal in women comprises two components: genital arousal and subjective arousal. Genital arousal is characterized by genital vasocongestion and other physiological changes that occur in response to sexual stimuli, whereas subjective arousal refers to mental engagement during sexual activity. For some women, genital arousal enhances subjective arousal; for others, the two types of arousal are desynchronous. However, the relationship between genital and subjective arousal might not be relevant to the diagnosis and treatment of sexual arousal dysfunction. Studies have shown that not all women who report sexual arousal problems have decreased genital arousal, and only some women with decreased genital arousal have low subjective arousal. To develop efficacious treatments for female sexual arousal dysfunction, researchers need to differentiate the women for whom genital sensations have a critical role in their subjective arousal from those who are not mentally aroused by genital cues. The mechanisms by which women become aroused and the inputs into arousal have considerable implications for treatment outcomes.

Genotype scores predict drug efficacy in subtypes of female sexual interest/arousal disorder: A double-blind, randomized, placebo-controlled cross-over trial

Attempts to develop a drug treatment for female sexual interest/arousal disorder have so far been guided by the principle of ‘one size fits all’, and have failed to acknowledge the complexity of female sexuality. Guided by personalized medicine, we designed two on-demand drugs targeting two distinct hypothesized causal mechanisms for this sexual disorder. The objective of this study was to design and test a novel procedure, based on genotyping, that predicts which of the two on-demand drugs will yield a positive treatment response. In a double-blind, randomized, placebo-controlled cross-over experiment, 139 women with female sexual interest/arousal disorder received three different on-demand drug-combination treatments during three 2-week periods: testosterone 0.5 mg + sildenafil 50 mg, testosterone 0.5 mg + buspirone 10 mg, and matching placebo. The primary endpoint was change in satisfactory sexual events. Subjects’ genetic profile was assessed using a microarray chip that measures 300,000 single-nucleotide polymorphisms. A preselection of single-nucleotide polymorphisms associated with genes that are shown to be involved in sexual behaviour were combined into a Phenotype Prediction Score. The Phenotype Prediction Score demarcation formula was developed and subsequently validated on separate data sets. Prediction of drug-responders with the Phenotype Prediction Score demarcation formula gave large effect sizes (d = 0.66 through 1.06) in the true drug-responders, and medium effect sizes (d = 0.51 and d = 0.47) in all patients (including identified double, and non-responders). Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the Phenotype Prediction Score demarcation formula were all between 0.78 and 0.79, and thus sufficient. The resulting Phenotype Prediction Score was validated and shown to effectively and reliably predict which women would benefit from which on-demand drug, and could therefore also be useful in clinical practice, as a companion diagnostic establishing the way to a true personalized medicine approach.

Recent Developments in Psychopharmaceutical Approaches to Treating Female Sexual Interest and Arousal Disorder

Purpose of Review

This review summarizes the recent literature and empirical studies on psychopharmacological approaches to treating female sexual interest/arousal disorder (FSIAD).

Recent Findings

Several new drugs for FSIAD that are intended to increase sexual responsiveness by influencing central excitatory and inhibitory neuromodulatory processes are under development. Studies on flibanserin resulted in the first approved medication for the treatment of low sexual desire in premenopausal women. New drugs under development are testosterone combined with sildenafil or buspiron, bremelanotide, BP101, and nasal testosterone (TBS-2).

Summary

Although pharmacological enhancement of sexual responsiveness may be potentially helpful in the treatment of FSIAD, the observed effects of flibanserin and other new drugs under development seem limited in terms of clinical significance. Given the multifactorial character of FSIAD, it may be important to integrate psychopharmacological treatment with sex therapy for optimal treatment efficacy.

Flavonoid glycosides isolated from Epimedium brevicornum and their estrogen biosynthesis-promoting effects

Epimedium brevicornum Maxim has a long history of use in the treatment of estrogen deficiency-related diseases. However, the chemical constituents and mechanism of action of this medicinal plant are not fully understood. In the present study, we isolated four new isoprenylated flavonoid glycosides, as well as 16 known flavonoids (13 isoprenylated flavonoids), from this plant. The chemical structures of the new flavonoid glycosides were elucidated by extensive spectroscopic analysis. The new compounds 1–4 were potent promoters of estrogen biosynthesis in human ovarian granulosa-like KGN cells. ZW1, an isoprenylated flavonoid analogue and a specific inhibitor of phosphodiesterase 5 (PDE5), was synthesized and used to explore the mechanism of the isoprenylated analogues on estrogen biosynthesis. ZW1 treatment increased estrogen production by upregulation of aromatase mRNA and protein expression. ZW1 increased the phosphorylation of cAMP response element-binding protein (CREB). Further study showed that the inhibition of PDE5 by ZW1 increased estrogen biosynthesis partly through suppression of phosphodiesterase 3 (PDE3). Our results suggested that the isoprenylated flavonoids from E. brevicornum may produce beneficial health effects through the promotion of estrogen biosynthesis. PDE5 warrants further investigation as a new therapeutic target for estrogen biosynthesis in the prevention and treatment of estrogen-deficiency related diseases.

Evidence-based treatments for low sexual desire in women

Low sexual desire is the most common sexual complaint in women, with multinational studies finding that at least a third of women experience low sexual desire. No single etiology for the development of Female Sexual Interest/Arousal Disorder, the diagnosis laid out by the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders, has been established. There has been considerable interest in pharmacological approaches to improving low desire, and agents targeting a range of neurotransmitters have been examined. To date, only flibanserin, a centrally acting medication targeting the serotonin, dopamine, and norepinephrine systems, has been approved by the Food and Drug Administration (FDA). Despite statistically significant effects on sexual desire, sexual distress, and sexually satisfying events, side-effects are significant, and flibanserin is completely contraindicated with alcohol. As such, there has been renewed interest in advancing the science of psychological approaches to low desire, including cognitive behavioral and mindfulness therapies.

Peripheral Female Genital Arousal as Assessed by Thermography Following Topical Genital Application of Alprostadil vs Placebo Arousal Gel: A Proof-of-Principle Study Without Visual Sexual Stimulation

Introduction

Female sexual arousal disorder is a pathophysiologic state characterized clinically by persistent or recurrent inability to attain or maintain an adequate lubrication-swelling response of sexual excitement until completion of sexual activity. Prior clinical experience with alprostadil products for men with erectile dysfunction supports its use in women with female sexual arousal disorder.

Aim

To compare the effect of topical alprostadil with over-the-counter (OTC) lubricant on female genital arousal in the absence of visual sexual stimuli.

Methods

Healthy premenopausal women without sexual dysfunction were recruited from the community to participate in the study. Of 17 women who consented, 10 were enrolled and completed the trial. The mean age of subjects was 32 years (range = 27–43). Study drug or placebo was applied topically to the genitals. Continuous temperature monitoring was performed. Participants completed questionnaires assessing genital sensation, effect, intensity, and duration.

Main Outcome Measures

Change in temperature from baseline in vestibule, clitoris and vulva.

Results

In all 10 subjects, topical alprostadil induced a statistically significant increase in temperature of the vestibule, clitoris, and vulva compared with the OTC lubricant. The most rapid difference in genital temperature between placebo and alprostadil was seen on the vulva, which demonstrated a significant difference at approximately 9 minutes. There was a significant difference in temperature seen for the vestibule and clitoris at 11 and 19 minutes, respectively. Sixty percent of women reported being aware or conscious of genital sensations with topical alprostadil, but not with OTC lubricant. Discordance was noted in 30% of subjects who reported being aware or conscious of genital sensations with the two treatments and 10% who reported not being aware or conscious of genital sensations with either treatment.

Conclusion

Topical alprostadil administered to healthy premenopausal women induced statistically significant, sustained increases in genital temperatures of the vestibule, clitoris, and vulva within 20 minutes compared with OTC lubricant.

Single dose sublingual testosterone and oral sildenafil vs. a dual route/dual release fixed dose combination tablet: a pharmacokinetic comparison

AIM

The aim was to compare the pharmacokinetic profiles of two formulations of a combination drug product containing 0.5 mg testosterone and 50 mg sildenafil for female sexual interest/arousal disorder. The prototype (formulation 1) consists of a testosterone solution for sublingual administration and a sildenafil tablet that is administered 2.5 h later. The dual route/dual release fixed dose combination tablet (formulation 2) employs a sublingual and an oral route for systemic uptake. This tablet has an inner core of sildenafil with a polymeric time delay coating and an outer polymeric coating containing testosterone. It was designed to increase dosing practicality and decrease potential temporal non-adherence through circumventing the relatively complex temporal dosing scheme.

METHODS

Twelve healthy premenopausal subjects received both formulations randomly on separate days. Blood was sampled frequently to determine the pharmacokinetics of free testosterone, total testosterone, dihydrotestosterone, sildenafil and N-desmethyl-sildenafil.

RESULTS

Formulation 2 had a higher maximum concentration (Cmax ) for testosterone, 8.06 ng ml(-1) (95% confidence interval [CI] 6.84, 9.28) and higher area under the plasma concentration-time curve (AUC), 7.69 ng ml(-1)  h (95% CI 6.22, 9.16) than formulation 1, 5.66 ng ml(-1) (95% CI 4.63, 6.69) and 5.12 ng ml(-1)  h (95% CI 4.51, 5.73), respectively. Formulation 2 had a lower Cmax for sildenafil, 173 ng ml(-1) (95% CI 126, 220) and a lower AUC, 476 ng ml(-1)  h (95% CI 401, 551) than formulation 1, 268 ng ml(-1) (95% CI 188, 348) and 577 ng ml(-1)  h (95% CI 462, 692), respectively. Formulation 2 released sildenafil after 2.75 h (95% CI 2.40, 3.10).

CONCLUSIONS

The dual route/dual release fixed dose combination tablet fulfilled its design criteria and is considered suitable for further clinical testing.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Female sexual interest/arousal disorder (FSIAD) is a significant problem impacting psychological well-being, but the pharmacotherapeutic options for this problem are lacking. The combined, on-demand, sublingual administration of low dose sublingual testosterone and oral administration of sildenafil is a novel pharmacotherapeutic option under development for FSIAD. In proof-of-concept trials, these compounds were successfully administered via different dosage forms (sublingual and oral) at different time points (separated by 2.5 h) because of their markedly different pharmacokinetic-pharmacodynamic profiles. For future larger scale studies and the clinical practice, this raises obvious adherence issues.

WHAT THIS STUDY ADDS

A newly developed dual route/dual release fixed dose combination tablet containing testosterone and sildenafil mimics the pharmacokinetic profile of these components when they are administered as different dosage forms, 2.5 h apart. This combination tablet is a suitable final pharmaceutical drug product that will be used in future studies.

The Female Sexual Response: Current Models, Neurobiological Underpinnings and Agents Currently Approved or Under Investigation for the Treatment of Hypoactive Sexual Desire Disorder

How a woman responds to sexual cues is highly dependent on a number of distinct, yet related, factors. Researchers have attempted to explain the female sexual response for decades, but no single model reigns supreme. Proper female sexual function relies on the interplay of somatic, psychosocial and neurobiological factors; misregulation of any of these components could result in sexual dysfunction. The most common sexual dysfunction disorder is hypoactive sexual desire disorder (HSDD). HSDD is a disorder affecting women across the world; a recent in-person diagnostic interview study conducted in the USA found that an estimated 7.4% of US women suffer from HSDD. Despite the disorder's prevalence, it is often overlooked as a formal diagnosis. In a survey of primary care physicians and obstetrics/gynaecology specialists, the number one reason for not assigning an HSDD diagnosis was the lack of a safe and effective therapy approved by the US Food and Drug Administration (FDA). This changed with the recent FDA approval of flibanserin (Addyi™) for the treatment of premenopausal women with acquired, generalized HSDD; there are still, however, no treatments approved outside the USA. HSDD is characterized by a marked decrease in sexual desire, an absence of motivation (also known as avolition) to engage in sexual activity, and the condition's hallmark symptom, marked patient distress. Research suggests that HSDD may arise from an imbalance of the excitatory and inhibitory neurobiological pathways that regulate the mammalian sexual response; top-down inhibition from the prefrontal cortex may be hyperactive, and/or bottom-up excitation to the limbic system may be hypoactive. Key neuromodulators for the excitatory pathways include norepinephrine, oxytocin, dopamine and melanocortins. Serotonin, opioids and endocannabinoids serve as key neuromodulators for the inhibitory pathways. Evolving treatment strategies have relied heavily on these crucial research findings, as many of the agents currently being investigated as treatment options for HSDD target and influence key players within these excitatory and inhibitory pathways, including various hormone therapies and centrally acting drugs, such as buspirone, bupropion and bremelanotide.

Pharmacokinetics of a prototype formulation of sublingual testosterone and a buspirone tablet, versus an advanced combination tablet of testosterone and buspirone in healthy premenopausal women

The study aimed to compare the kinetics of two novel combination drug products for Female Sexual Interest/Arousal Disorder (FSIAD). Thirteen women received testosterone via the sublingual route followed 2.5 hours later by a buspirone tablet, versus a single combination tablet swallowed at once. The first clinical prototype consisted of a sublingual solution containing testosterone (0.5 mg) complexed with cyclodextrin and a tablet containing 10 mg buspirone, in a gelatin capsule to ensure blinding during the clinical studies. The innovative fixed-combination tablet consists of an inner-core component of 10 mg buspirone coated with a polymeric time-delay coating and an outer polymeric coating containing testosterone with hydroxypropyl-beta cyclodextrin. We observed an immediate testosterone pulse absorption from both formulations. We also demonstrated that there was adequate absorption of buspirone (>80 % relative to the conventional tablet) and a time delay in release of buspirone of 3.3 hours, close to the 3.0 hours of the reference formulation that showed clinical efficacy in early proof-of-principle studies. The newly developed combination tablet fulfils its design criteria and is a convenient tablet for further clinical studies in FSIAD.

Multiple hormonal dysregulation as determinant of low physical performance and mobility in older persons

Mobility-disability is a common condition in older individuals. Many factors, including the age-related hormonal dysregulation, may concur to the development of disability in the elderly. In fact, during the aging process it is observed an imbalance between anabolic hormones that decrease (testosterone, dehydroepiandrosterone sulphate (DHEAS), estradiol, insulin like growth factor-1 (IGF-1) and Vitamin D) and catabolic hormones (cortisol, thyroid hormones) that increase. We start this review focusing on the mechanisms by which anabolic and catabolic hormones may affect physical performance and mobility. To address the role of the hormonal dysregulation to mobility-disability, we start to discuss the contribution of the single hormonal derangement. The studies used in this review were selected according to the period of time of publication, ranging from 2002 to 2013, and the age of the participants (≥65 years). We devoted particular attention to the effects of anabolic hormones (DHEAS, testosterone, estradiol, Vitamin D and IGF-1) on both skeletal muscle mass and strength, as well as other objective indicators of physical performance. We also analyzed the reasons beyond the inconclusive data coming from RCTs using sex hormones, thyroid hormones, and vitamin D (dosage, duration of treatment, baseline hormonal values and reached hormonal levels). We finally hypothesized that the parallel decline of anabolic hormones has a higher impact than a single hormonal derangement on adverse mobility outcomes in older population. Given the multifactorial origin of low mobility, we underlined the need of future synergistic optional treatments (micronutrients and exercise) to improve the effectiveness of hormonal treatment and to safely ameliorate the anabolic hormonal status and mobility in older individuals.

Women taking the "blue pill" (sildenafil citrate): such a big deal?

For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra^®) in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate) should be kept as the last option.

Development of the Sexual Five-Facet Mindfulness Questionnaire (FFMQ-S): Validation Among a Community Sample of French-Speaking Women

It has been recently demonstrated that mindfulness-based intervention may be particularly suitable for addressing sexual difficulties in women. Although the Five-Facet Mindfulness Questionnaire (FFMQ) is currently one of the most widely used scales to assess mindfulness, no adaptation and validation of the FFMQ to measure female sexual functioning has been published. The main aim of this study was to develop and validate a sexual version of the Five Facets Mindfulness Questionnaire (FFMQ-S) to specifically measure mindfulness in the context of sexual encounters. A total of 251 healthy, French-speaking female volunteers were administered the FFMQ-S, the original FFMQ, and the Female Sexual Distress Scale (FSDS-R). Confirmatory factor analyses indicated that the FFMQ-S exhibits a five-factor model, as implied by the original FFMQ. Good scale reliability was observed. The FFMQ-S showed significant correlations with the FSDS-R and the usual FFMQ. Scores on the FFMQ-S correlated significantly more negatively with the total FSDS-R score than with the total score of the original version of the FFMQ. These findings clearly support the relevance of developing a version of the FFMQ tailored to sexual functioning.

Sexual desire, not hypersexuality, is related to neurophysiological responses elicited by sexual images

BACKGROUND

Modulation of sexual desires is, in some cases, necessary to avoid inappropriate or illegal sexual behavior (downregulation of sexual desire) or to engage with a romantic partner (upregulation of sexual desire). Some have suggested that those who have difficulty downregulating their sexual desires be diagnosed as having a sexual 'addiction'. This diagnosis is thought to be associated with sexual urges that feel out of control, high-frequency sexual behavior, consequences due to those behaviors, and poor ability to reduce those behaviors. However, such symptoms also may be better understood as a non-pathological variation of high sexual desire. Hypersexuals are thought to be relatively sexual reward sensitized, but also to have high exposure to visual sexual stimuli. Thus, the direction of neural responsivity to sexual stimuli expected was unclear. If these individuals exhibit habituation, their P300 amplitude to sexual stimuli should be diminished; if they merely have high sexual desire, their P300 amplitude to sexual stimuli should be increased. Neural responsivity to sexual stimuli in a sample of hypersexuals could differentiate these two competing explanations of symptoms.

METHODS

Fifty-two (13 female) individuals who self-identified as having problems regulating their viewing of visual sexual stimuli viewed emotional (pleasant sexual, pleasant-non-sexual, neutral, and unpleasant) photographs while electroencephalography was collected.

RESULTS

Larger P300 amplitude differences to pleasant sexual stimuli, relative to neutral stimuli, was negatively related to measures of sexual desire, but not related to measures of hypersexuality.

CONCLUSION

Implications for understanding hypersexuality as high desire, rather than disordered, are discussed.

Pharmacokinetics of three doses of sublingual testosterone in healthy premenopausal women

CONTEXT

Sublingual testosterone is a single-dose treatment often used in studies regarding social, cognitive and sexual behavior. It is hypothesized that an increase in the ratio of free to total testosterone (free fraction) is indirectly, via genomic effects, responsible for the behavioral effects after sublingual testosterone administration.

OBJECTIVE

To characterize the pharmacokinetics of three doses sublingual testosterone in premenopausal women. Also, to investigate the SHBG saturation threshold influencing the free level and free fraction of testosterone.

DESIGN

We conducted an investigator-blind, randomized, cross-over placebo controlled study.

SETTING

This study was undertaken at the research and development department of a scientific company for research regarding female sexual dysfunction.

PARTICIPANTS

16 healthy premenopausal women (mean age 27.3±5.3 years).

INTERVENTIONS

Sublingual testosterone solution; 0.25, 0.50 and 0.75 mg.

MAIN OUTCOMES MEASURE

The pharmacokinetics of three single doses sublingual testosterone solution; the influence of SHBG levels on free and total levels of testosterone.

RESULTS

After sublingual testosterone administration, serum free and total testosterone levels peaked at 15 min and reached baseline levels within 150 min. The AUCs and C(max) of free and total testosterone differed significantly between the three doses (p<0.0001) and increased dose-dependently. A dose-dependent increase in free fraction of testosterone was found in women with low SHBG levels, but not in women with high SHBG levels.

CONCLUSIONS

The three doses sublingual testosterone are rapidly absorbed and quickly metabolized in premenopausal women. These data demonstrate the influence of SHBG levels on the treatment induced alterations in plasma free testosterone.

The role of androgens and estrogens on healthy aging and longevity

Aging is associated with a loss of sex hormone in both men (andropause) and women (menopause). In men, reductions in testosterone can trigger declines in muscle mass, bone mass, and in physical function. In women, the impact of the loss of sex hormones, such as estradiol, on bone is well elucidated, but evidence is limited on whether the loss of estradiol negatively affects muscle mass and physical function. However, deficiencies in multiple anabolic hormones have been shown to predict health status and longevity in older persons. Thus, consideration should be given as to whether targeted hormone replacement therapies may prove effective at treating clinical conditions, such as age-related sarcopenia, cancer cachexia, and/or acute or chronic illnesses. If initiated carefully in the appropriate clinical population, hormone replacement therapies in men and women may prevent and reverse muscle and bone loss and functional declines and perhaps promote healthy aging and longevity.

Acute effects of steroid hormones and neuropeptides on human social-emotional behavior: a review of single administration studies

Steroids and peptides mediate a diverse array of animal social behaviors. Human research is restricted by technical-ethical limitations, and models of the neuroendocrine regulation of social-emotional behavior are therefore mainly limited to non-human species, often under the assumption that human social-emotional behavior is emancipated from hormonal control. Development of acute hormone administration procedures in human research, together with the advent of novel non-invasive neuroimaging techniques, have opened up opportunities to systematically study the neuroendocrinology of human social-emotional behavior. Here, we review all placebo-controlled single hormone administration studies addressing human social-emotional behavior, involving the steroids testosterone and estradiol, and the peptides oxytocin and vasopressin. These studies demonstrate substantial hormonal control over human social-emotional behavior and give insights into the underlying neural mechanisms. Finally, we propose a theoretical model that synthesizes detailed knowledge of the neuroendocrinology of social-emotional behavior in animals with the recently gained data from humans described in our review.

The testosterone metabolite 3α-diol enhances female rat sexual motivation when infused in the nucleus accumbens shell

AIM

The purpose of this study was to provide a quantitative assessment of female rat sexual behaviors after acute exposure to the A-ring reduced testosterone metabolite, androstanediol (3α-Diol), through the nucleus accumbens (NA) shell.

MAIN OUTCOME MEASURES

Quantitative analyses of female rat sexual behaviors and assessment of protein levels for the enzyme glutamic acid decarboxylase isoform 67 (GAD67) and gephyrin, a protein that participates in the clustering of GABA-A receptors in postsynaptic cells, were accomplished.

METHODS

Female rats were ovariectomized and primed with estrogen and progesterone to induce sexual behaviors. Females received a 3α-Diol infusion via guided cannula that aimed to the NA shell five minutes prior to a sexual encounter with a stud male. The following parameters were videotaped and measured in a frame by frame analysis: lordosis quotient (LQ), Lordosis rating (LR), frequency and duration of proceptive behaviors (hopping/darting and ear wiggling). Levels of GAD67 and gephyrin were obtained by Western blot analysis two or twenty-four hours after the sexual encounter.

RESULTS

Acute exposure to 3α-Diol in the NA shell enhanced LR, ear wiggling, and hopping/darting but not LQ. Some of these behavioral effects were counteracted by co-infusion of 3α-Diol plus the GABAA-receptor antagonist GABAzine. A transient reduction of GAD67 levels in the NA shell was detected.

CONCLUSIONS

The testosterone metabolite 3α-Diol enhances sexual proceptivity, but not receptivity, when infused into the NA shell directly. The GABAergic system may participate in the androgen-mediated enhancement of female rat sexual motivation.

Testosterone administration impairs cognitive empathy in women depending on second-to-fourth digit ratio

During social interactions we automatically infer motives, intentions, and feelings from bodily cues of others, especially from the eye region of their faces. This cognitive empathic ability is one of the most important components of social intelligence, and is essential for effective social interaction. Females on average outperform males in this cognitive empathy, and the male sex hormone testosterone is thought to be involved. Testosterone may not only down-regulate social intelligence organizationally, by affecting fetal brain development, but also activationally, by its current effects on the brain. Here, we show that administration of testosterone in 16 young women led to a significant impairment in their cognitive empathy, and that this effect is powerfully predicted by a proxy of fetal testosterone: the right-hand second digit-to-fourth digit ratio. Our data thus not only demonstrate down-regulatory effects of current testosterone on cognitive empathy, but also suggest these are preprogrammed by the very same hormone prenatally. These findings have importance for our understanding of the psychobiology of human social intelligence.

Disorders in sexual desire and sexual arousal in women, a 2010 state of the art

In this contribution, female sexual desire and arousal disorders are viewed from the perspective of incentive motivation and information processing models of sexual response. The effects of hormones, somatic disease, and medication on sexual arousability are discussed, as well as the influence of psychological factors, such as stimulus meaning, mood and cognition, and relational context on female sexual desire and arousal. Specific topics to attend to during the anamnesis of sexual desire and arousal problems, and empirically evaluated psychological and pharmacological treatments for these problems are discussed.

Testosterone decreases trust in socially naive humans

Trust plays an important role in the formation and maintenance of human social relationships. But trusting others is associated with a cost, given the prevalence of cheaters and deceivers in human society. Recent research has shown that the peptide hormone oxytocin increases trust in humans. However, oxytocin also makes individuals susceptible to betrayal, because under influence of oxytocin, subjects perseverate in giving trust to others they know are untrustworthy. Testosterone, a steroid hormone associated with competition and dominance, is often viewed as an inhibitor of sociality, and may have antagonistic properties with oxytocin. The following experiment tests this possibility in a placebo-controlled, within-subjects design involving the administration of testosterone to 24 female subjects. We show that compared with the placebo, testosterone significantly decreases interpersonal trust, and, as further analyses established, this effect is determined by those who give trust easily. We suggest that testosterone adaptively increases social vigilance in these trusting individuals to better prepare them for competition over status and valued resources. In conclusion, our data provide unique insights into the hormonal regulation of human sociality by showing that testosterone downregulates interpersonal trust in an adaptive manner.

Hormone treatment and muscle anabolism during aging: androgens

Aging is associated with a gradual decline in circulating testosterone concentrations and decreased musculature in men. While testosterone administration is often considered when symptoms of hypogonadism are presented, the long-term effects of androgen use on muscle physiology are not yet fully understood. The definition of hypogonadism in men remains obscure but is generally indicated by total testosterone concentrations less than a threshold value of 300-500 ng/dL. Androgen replacement therapy is generally safe in men and women with low endogenous testosterone concentrations. The development of selective androgen receptor modulators (SARMs) may provide additional options in treatment of hypogonadism while lowering the potential of side effects often associated with long-term androgen use. Androgen administration, either alone or in combination with other treatments, can be successful in improving muscle mass by increasing protein anabolism and reducing protein catabolism in men and women. Further research is necessary to optimize the anabolic and anticatabolic properties of androgens for treatment and prevention of muscle loss in men and women.

Female sexual dysfunction in urological patients: findings from a major metropolitan area in the USA

OBJECTIVE

To determine the prevalence of and risk factors for female sexual dysfunction (FSD) in a practice focused mainly on female urology.

PATIENTS AND METHODS

A modified version of the Female Sexual Function Index (FSFI) was used to assess the prevalence of FSD in 587 patients who completed the questionnaire. Logistic regression was used to identify risk factors.

RESULTS

The prevalence of FSD was 63%; age, menopausal status and usage of selective serotonin reuptake inhibitors were statistically significant risk factors for FSD.

CONCLUSIONS

FSD is highly prevalent in this population of patients and screening female urological patients for FSD should be considered.

Phosphodiesterase type 5 inhibitors and female sexual response: faulty protocols or paradigms?

INTRODUCTION

Phosphodiesterase type 5 inhibitors (PDE5), such as sildenafil, tadalafil, and vardenafil, have revolutionized the treatment of erectile dysfunction. Few successes, in contrast, have been reported for the use of these agents in treatment of sexual arousal problems in women.

AIM

To review research examining efficacy of PDE5 in women, critique the methods and models employed, and integrate the findings within a broader, gender-specific understanding of female sexual response.

METHODS

A conceptual and methodological review of all published studies examining PDE5 efficacy in female samples.

MAIN OUTCOME MEASURES

Study methods, populations, outcome measures, study results.

RESULTS

A total of 16 studies were reviewed. Studies using self-reported measures of sexual functioning showed mixed results whereas studies examining physiological effects of PDE5 on genital vasocongestion consistently report significant effects on genital sexual response.

CONCLUSIONS

The lack of efficacy of PDE5 treatment in women is likely attributable to gender differences in the concordance between physiological and psychological components of sexual response. Discordance between genital and subjective measures of sexual response in women may be augmented by PDE5 effects on genital vasocongestion in some populations, rendering successful treatment unlikely via pharmacological treatment alone.