Ontogenetic profile of the expression of thyroid hormone receptors in rat and human corpora cavernosa of the penis

Thyroid disorders and male sexual dysfunction

Though early research suggested that thyroid hormones were not involved with the testes, male spermatogenesis, or erectile function, investigations on this topic over the past few decades have increased and shed new light. A literature review of studies conducted between 1963 and 2022 regarding male sexual dysfunction (SD) and thyroid disorders was performed to define the diagnostic consideration, pathophysiology, and management of SD secondary to thyroid dysregulation. This article provides evidence and interpretation of prior clinical and preclinical studies and contextualizes these studies for clinical practice. Clinical manifestations of SDs included erectile and ejaculatory dysfunction, impaired spermatogenesis, and disruption of the hypothalamic-pituitary-gonadal axis. Our aim of this communication was to perform a literature review detailing the impact of thyroid disorders on male SD. We hope to provide a framework for practicing urologists, endocrinologists, or general practitioners when evaluating patients with concurrent thyroid and male SD. It is important to recognize that thyroid disorders can be an important part of the pathophysiology of male SD in patients. Future research studies are needed to further elucidate the mechanisms involved.

Thyroid diseases and female sexual dysfunctions

INTRODUCTION

Female sexual dysfunctions (FSDs) have received little attention in the context of thyroid diseases, despite the high prevalence of both conditions.

OBJECTIVES

This review aims to update and summarize the state of knowledge on the association between thyroid diseases and FSDs and to investigate the complex mechanisms through which thyroid hormone imbalance can impact female sexual health in the context of the biopsychosocial model.

METHODS

A comprehensive literature search was performed through the PubMed, MEDLINE, and Scopus databases, using the following keywords: "female sexual function," "sexual dysfunction," "hypoactive sexual desire disorder," "thyroid disease," "thyroiditis," "hypothyroidism," and "hyperthyroidism."

RESULTS

To date, well-designed studies that describe the relationship between FSDs and thyroid disorders are lacking. However, despite the limitations on available studies, current data indicate that sexual alterations are frequently associated with thyroid diseases in women. A complex interplay of direct and indirect hormonal and nonhormonal mechanisms has been hypothesized, including hormonal changes, neurotransmitter imbalance, reduced nitric oxide release, mood disorders, and other systemic consequences of both hypothyroidism and hyperthyroidism. Thyroid hormone receptors have also been identified in the genitourinary system.

CONCLUSIONS

In a clinical setting, physicians should investigate the sexuality of patients consulting for thyroid disease. At the same time, an evaluation of thyroid function should be performed in patients presenting with FSD, especially after menopause, when the risk of thyroid diseases and FSDs increases strongly.

The Italian Society of Andrology and Sexual Medicine (SIAMS), along with ten other Italian Scientific Societies, guidelines on the diagnosis and management of erectile dysfunction

PURPOSE

Erectile dysfunction (ED) is one of the most prevalent male sexual dysfunctions. ED has been in the past mistakenly considered a purely psycho-sexological symptom by patients and doctors. However, an ever-growing body of evidence supporting the role of several organic factors in the pathophysiological mechanisms underlying ED has been recognized.

METHODS

The Italian Society of Andrology and Sexual Medicine (SIAMS) commissioned an expert task force involving several other National Societies to provide an updated guideline on the diagnosis and management of ED. Derived recommendations were based on the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system.

RESULTS

Several evidence-based statements were released providing the necessary up-to-date guidance in the context of ED with organic and psychosexual comorbidities. Many of them were related to incorrect lifestyle habits suggesting how to associate pharmacotherapies and counseling, in a couple-centered approach. Having the oral therapy with phosphodiesterase type 5 inhibitors as the gold standard along with several other medical and surgical therapies, new therapeutic or controversial options were also discussed.

CONCLUSIONS

These are the first guidelines based on a multidisciplinary approach that involves the most important Societies related to the field of sexual medicine. This fruitful discussion allowed for a general agreement on several recommendations and suggestions to be reached, which can support all stakeholders in improving couple sexual satisfaction and overall general health.

Hyperthyroidism as an Underlying Cause of Premature Ejaculation

INTRODUCTION

Hormonal imbalances have been associated with various sexual dysfunction disorders. In particular, the connection of hyperthyroidism has been discovered to correlate to premature ejaculation (PE) but has yet to been thoroughly elucidated. As one of the most frequently self-reported sexual dysfunctions, it is imperative for health care professionals to evaluate possible underlying conditions in regard to treatment options for individuals with PE.

OBJECTIVES

To review the literature regarding hyperthyroidism effects on sexual dysfunction, with a focus on hyperthyroidism and PE.

METHODS

A literature review of articles and clinical studies was performed to define the classification, pathophysiology, diagnostic considerations, and management of hyperthyroidism on PE. Search terms included "hyperthyroidism" and/or "premature ejaculation," "treatment of premature ejaculation," "defining premature ejaculation," and "management of premature ejaculation."

RESULTS

To improve the accuracy of diagnosing PE, there needs to be a set definition amongst the different guidelines, as using these guidelines can help determine possible underlying etiologies of PE. The correlation of hyperthyroidism and PE has been described in a limited number of studies. It has been reported that individuals with hyperthyroidism are much more likely to have PE than individuals with euthryoidism. Management of hyperthyroidism has been shown to alleviate the symptoms of PE.

CONCLUSION

Further understanding of hyperthyroidism as an underlying cause of PE could lead to increased efficacy of treatment and management of PE. Tannenbaum J, Youssef M, Attia AS, et al. Hyperthyroidism as an Underlying Cause of Premature Ejaculation. Sex Med Rev 2021;XX:XXX-XXX.

Is There a Role for Levo-Thyroxine for the Treatment of Arterial Erectile Dysfunction? The Clinical Relevance of the Mean Platelet Volume

BACKGROUND

Arterial erectile dysfunction (ED) is an early sign of vascular damage. Rare evidence has been published so far as to whether subclinical hypothyroidism (SCH) affects arterial erectile function. Therefore, the objective of this study was to fill this gap.

METHODS

Patients with arterial ED and SCH were consecutive enrolled and randomly divided into Group A (n = 20) and Group B (n = 20). Group A was treated with levo-thyroxine (LT4) at the dose of 1 µg/kg/day for six months, whereas patients of the group B did not receive any treatment. Thyroid stimulating hormone (TSH), free-thyroxine (FT4), peak systolic velocity (PSV), International Index of Erectile Function 5-item version (IIEF-5) score, mean platelet volume (MPV), and total cholesterol were evaluated at enrollment (T0) and after six months (T1). Patients without hypertension, diabetes mellitus, dyslipidemia, not on drugs, and with normal total testosterone (TT) values were included in this study.

RESULTS

Group A and B did not differ for age (61.2 ± 4.8 vs. 60.3 ± 5.6 years), body-mass index (28.7 ± 2.5 vs. 28.3 ± 2.6 Kg/m²), and serum TT levels (481.2 ± 54.0 vs. 492.1 ± 59.7 ng/dL). At T0, serum TSH levels (6.5 ± 1.2 vs. 6.0 ± 1.0 µIU/mL), FT4 (8.8 ± 0.6 vs. 8.8 ± 0.6 pmol/L), PSV (26.5 ± 1.4 vs. 25.8 ± 2.1 cm/s), IIEF-5 score (8.2 ± 1.7 vs. 9.0±1.7), and total cholesterol (167.8 ± 21.7 vs. 171.6 ± 21.3 mg/dL) did not significantly differ in patients of Group A vs. those of Group B. MPV was significantly higher in Group A than in Group B (12.3 ± 0.3 vs. 11.8±0.7 fL). At T1, Group A showed significantly lower TSH (2.26 ± 0.5 µIU/mL), MPV (9.5 ± 0.3 fL), and total cholesterol (137.8 ± 29.2 mg/dL) and significantly higher FT4 (9.3 ± 0.4 pmol/L), PSV (40.0 ± 2.6 cm/s), and IIEF-5 score (20.2 ± 3.6) compared to pre-treatment values. None of these endpoints showed significant change at T1 compared to T0 in patients of group B.

CONCLUSIONS

Lt4 therapy is associated with an improvement of the erectile function at the vascular level, a decrease in MPV and total cholesterol. LT4 therapy should be considered in patients with arterial ED and SCH.

Gender difference and correlation between sexuality, thyroid hormones, cognitive, and physical functions in elderly fit

PURPOSE

Sexuality in the elderly is related to psycho-physical well-being. Aim of this study was to analyze the correlation between sexual health, thyroid hormones, cognitive functions, and physical fitness in elderly population.

METHODS

Fifty-one fit adults were recruited (age: 71.9 ± 5.3 years, 26 females and 25 males). Sexuality was evaluated using the Changes in Sexual Functioning Questionnaire-short form (CSFQ-14) and the Sexual Attitude Scale (SAS). Thyroid function was assessed by measuring serum TSH, FT3, and FT4. Cognitive functions and depressive symptoms were evaluated by the Mini Mental State Examination (MMSE) test and Geriatric Depression Scale (GDS) scores. Subjects' physical fitness was evaluated using the following tests: Short Physical Performance Battery (SPPB), Handgrip test (HG), Timed Up and Go test (TUG), and 2-Minute step test (ST).

RESULTS

CSFQ-14 positively correlated with MMSE (p < 0.05) and negatively with GDS (p < 0.05), while thyroid function was not correlated with sexuality, in both genders. A negative relationship between FT4 vs. weight, FT3 vs. HG and FT3/FT4 ratio vs. ST were found (p = 0.05) in females, while in males, it occurred for TSH vs. TUG (p < 0.05); a positive relationship existed in females between FT4 vs. ST (p < 0.05). Finally, CSFQ-14 was significantly correlated with SPPB (p < 0.05), CST, TUG, and ST (p < 0.01), in both genders.

CONCLUSION

We demonstrated a strict relationship between active sexuality, preserved cognitive function and appropriate physical fitness in elderly subjects, independently from gender. Our preliminary data suggest that in elderly fit population, peripheral thyroxin deiodination may be a useful predictor of better physical performance and more successful aging.

The association between subclinical hypothyroidism and erectile dysfunction

Objectives

Erectile dysfunction (ED) is highly prevalent among males, and hypothyroidism is previously reported to be related with ED. However there have been rare studies to investigate the association between subclinical hypothyroidism (SCH) and ED, hence our objective was to fill this gap.

Methods

ED patients who visited the Urology Outpatients Clinic owere recruited consecutively, and males from the Health Manage Center were included as the controls. Serum thyroid and sexual hormones were estimated, and the International Index of Erectile Function (IIEF-5) questionnaires were evaluated as well. Subjects with normal sexual hormones were included for statistical analysis.

Results

One hundred nine ED patients and 32 healthy controls were included in this study. The ratio of SCH and euthyroidism in ED males was 29.36% and 66.06% respectively. The IIEF-5 scores in ED patients with SCH were significantly lower than the controls with euthyroidism (P<0.05). The serum concentrations of TSH and prolactin were significantly higher and free thyroxine lower in ED patients with SCH when compared with the controls with euthyroidism (all p<0.05), and no significant differences of estradiol and total testosterone were found between those two groups. However the IIEF-5 scores were not significantly different between males with SCH and euthyroidism among ED patients (P>0.05).

Conclusions

SCH is common in ED patients and may be associated with ED, whereas the severity of ED is not related to SCH. Screening for thyroid dysfunction in men presenting with ED is recommended.

Longer trinucleotide repeats of androgen receptor are associated with higher testosterone and low oxytocin levels in diabetic premature ejaculatory dysfunction patients

Background

Despite its worldwide high occurrence, the obscurity regarding the description, epidemiology and management of premature ejaculation remains provocative. It is well established that male premature ejaculatory dysfunction is an increasing problem due to spontaneous ejaculation across a variety of general and clinical subjects. The main goal of this study was to determine the relationships between trinucleotide repeats of the androgen receptor (AR), sex steroids, and pituitary hormones with sexual function in men with type 2 diabetes mellitus (DM) and reported with acquired premature ejaculation (PE).

Methods

A total of 150 normal and 250 PE + DM subjects were enrolled in this study. Each subject was invited to fill out an elaborative questionnaire to acquire precise selective information regarding BMI, duration of PE + DM, self-reported Intra-Vaginal Ejaculatory Latency Time (IELT), sexual and mental health status by using the premature ejaculation diagnostic tool (PEDT) and Beck Depression Inventory-II (BDI-II). Pearson's correlation analysis was used to analyze the relationship between clinical, hormonal, and genetic variables. Ward's minimum variance cluster analysis and principal component analysis were used for evaluation of dependence between genetic, clinical, and demographic parameters.

Results

The patients who have the lowest number of (≤21) (CAG)n repeats have higher serum oxytocin levels (114.2 pg/ml; n = 54, 43.2%) than the controls (69.18 pg/ml; n = 22, 17.6%) and the patients with the highest (≥26) number of (CAG)n repeats (62.9 pg/ml; n = 108, 43.2%).On the other hand, patients who have the highest numbers of (CAG)n repeats (≥26) have higher serum testosterone (6.1 ng/ml; n = 108, 43.2% of cohort) lower prolactin (3.01 ng/ml; n = 108, 43.2% of cohort) levels than the controls and patients with the lowest numbers (≤21) of (CAG)n repeats and their TSH (1.53 mIU/L, P < 0.05) levels are lower than those of controls. In the Pearson correlation model, self-estimated IELT demonstrated significantly negative correlation with both (CAG)n and (GCC)n repeats (r = - 0.16, p = 0.0001; r = - 0.19, p = 0.0001) respectively. These repeats have positive correlation with PEDT (r = 0.28, p = 0.0001: r = 0.24, p = 0.0001, whole model) and inversely correlated with BDI-II (r = - 0.25, p = 0.0001).

Conclusion

This study indicates that androgen receptor polymorphism modulates the endocrine effect on ejaculatory reflex and depends strongly on its "cofactors". Moreover, our results also confirmed an association between long tri-nucleotide repeats of androgen receptor, sex steroids, pituitary, and thyroid hormones in relation to  acquired premature ejaculatory dysfunction in diabetic patients. However, endocrine regulation of PE reflex is a complex phenomenon that requires further investigation.

Premature ejaculation: challenging new and the old concepts

Premature ejaculation remains a difficult condition to manage for patients, their partners, and the clinician. Whilst prevalence rates are estimated to be 20-40%, determining a diagnosis of premature ejaculation is difficult, as the definition remains both subjective and ill-defined in the clinical context. As our understanding of the ejaculatory pathway has improved, new opportunities to treat the condition have evolved with mixed results. In this review, we explore some of these controversies surrounding the aetiology, diagnosis, and treatment of this condition and discuss potential novel therapeutic options.

Distribution of thyroid hormone and thyrotropin receptors in reproductive tissues of adult female rabbits

PURPOSE

Thyroid dysfunctions are related to anovulation, miscarriages, and infertility in women and laboratory animals. Mechanisms associated with these effects are unknown, although indirect or direct actions of thyroid hormones and thyrotropin could be assumed. The present study aimed to identify the distribution of thyroid hormones (TRs) and thyrotropin (TSHR) receptors in reproductive organs of female rabbits.

MATERIAL AND METHODS

Ovary of virgin and pregnant rabbits, as well as the oviduct, uterus, and vagina of virgin rabbits were excised, histologically processed, and cut. Slices from these organs were used for immunohistochemical studies for TRα1-2, TRß1, and TSHR.

RESULTS

The presence of TRs and TSHR was found in the primordial, primary, secondary, tertiary, and Graafian follicles of virgin rabbits, as well as in the corpora lutea, corpora albicans, and wall of hemorrhagic cysts of pregnant rabbits. Oviductal regions (fimbria-infundibulum, ampulla, isthmus, and utero-tubal junction), uterus (endometrium and myometrium), and vagina (abdominal, pelvic, and perineal portions) of virgin rabbits showed anti-TRs and anti-TSHR immunoreactivity. Additionally, the distal urethra, paravaginal ganglia, levator ani and iliococcygeus muscles, dorsal nerve and body of the clitoris, perigenital skin, and prostate had TRs and TSHR.

CONCLUSIONS

The wide presence of TRs and TSHR in female reproductive organs suggests varied effects of thyroid hormones and thyrotropin in reproduction.

Epidemiology of delayed ejaculation

A large body of literature on diminished ejaculatory disorders has been generated without the use of a clear diagnostic definition. Many studies have not distinguished between the orgasm and ejaculation disorders leading to doubtful results. Delayed ejaculation (DE) is one of the diminished ejaculatory disorders, which range from varying delays in ejaculatory latency to a complete inability to ejaculate. The present review is aimed at providing a comprehensive overview of the current knowledge on the definition and epidemiology of diminished ejaculatory disorders. We focus on the acquired diseases, such as benign prostatic hyperplasia (BPH) and specific drug regimens that may cause an iatrogenic form of ejaculatory disorder. In addition, the impact of aging is discussed since the prevalence of DE appears to be moderately but positively related to age. Finally, we also focus on the importance of the hormonal milieu on male ejaculation. To date, evidence on the endocrine control of ejaculation is derived from small clinical trials, but the evidence suggests that hormones modulate the ejaculatory process by altering its overall latency.

Dapoxetine and the treatment of premature ejaculation

Background

Premature ejaculation (PE) is the most common male sexual complaint. Off-label oral selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for the treatment of PE. Dapoxetine is a short-acting SSRI specifically designed for on-demand use. The objective of this communication is to summarize the clinical and physiological evidence regarding the role of the serotonergic pathway and specifically dapoxetine in the treatment of PE.

Methods

A PubMed search was conducted on articles reporting data on dapoxetine for the treatment of PE. Articles describing the pathophysiology and treatment options for PE were additionally included for review.

Results

The etiology of PE is multi-factorial in nature. There are many treatment options for PE such as psychological/behavioral therapy, topical anesthetic agents, phosphodiesterase type 5 (PDE-5) inhibitors, and tramadol hydrochloride. SSRIs play a major role in PE treatment. Animal and clinical studies in addition to its pharmacokinetic document dapoxetine’s clinical efficacy and safety for on-demand treatment of PE.

Conclusions

Dapoxetine demonstrates clinical efficacy and a favorable side effect profile. Dapoxetine is currently the oral drug of choice for on-demand treatment of PE.

Is thyroid hormones evaluation of clinical value in the work-up of males of infertile couples?

STUDY QUESTION

Is thyroid hormones (TH) evaluation of clinical value in the work-up of males of infertile couples?

STUDY ANSWER

Our results suggest that TH evaluation is not mandatory in the work-up of male infertility.

WHAT IS KNOWN ALREADY

A few previous studies performed on a limited series of subjects reported a negative impact of hyper- and hypo-thyroidism on semen volume, sperm concentration, progressive motility and normal morphology. No previous study has systematically evaluated associations between TH variation, semen parameters and ultrasound characteristics of the male genital tract.

STUDY DESIGN, SIZE AND DURATION

Cross-sectional analysis of a consecutive series of 172 subjects seeking medical care for couple infertility from September 2010 to November 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of the entire cohort, 163 men (age 38.9 ± 8.0 years) free of genetic abnormalities were studied. All subjects underwent a complete andrological and physical examination, biochemical and hormonal assessment, scrotal and transrectal colour-Doppler ultrasound (CDUS) and semen analysis (including seminal interleukin 8 levels, sIL-8) evaluation within the same day.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the patients studied, 145 (88.9%) showed euthyroidism, 6 (3.7%) subclinical hyper- and 12 (7.4%) subclinical hypo-thyroidism. No subjects showed overt hyper- or hypo-thyroidism. At univariate analysis, no associations among thyroid-stimulating hormone (TSH) or TH levels and sperm parameters were observed. Conversely, we observed positive associations among free triiodothyronine (fT3) and free thyroxine (fT4) levels, ejaculate volume and seminal fructose levels. In a multivariate model, after adjusting for confounders such as age, body mass index, smoking habit, sexual abstinence, calculated free testosterone, prolactin and sIL-8 levels, only the associations found for fT3 levels were confirmed. When CDUS features were investigated, using the same multivariate model, we found positive associations between fT3 levels and seminal vesicles (SV) volume, both before and after ejaculation (adj. r = 0.354 and adj. r = 0.318, both P < 0.0001), as well as with SV emptying (ΔSV volume; adj. r = 0.346, P < 0.0001) and echo-texture inhomogeneity. In addition, after adjusting for confounders, negative associations between fT4 levels and epididymal body and tail diameters were found. No significant associations between TSH or TH levels and CDUS features of other organs of the male genital tract, including testis and prostate, were found. Finally, when the features of subjects with euthyroidism, subclinical hypo- and hyper-thyroidism were compared, no significant differences in seminal or hormonal parameters were found. Conversely, evaluating CDUS parameters, subjects with subclinical hyperthyroidism showed a higher difference between the SV longitudinal diameters measured before and after ejaculation when compared with that of subclinical hypothyroid men, even after adjusting for confounders (P < 0.007). All the other male genital tract CDUS characteristics did not differ among groups.

LIMITATIONS, REASONS FOR CAUTION

First, the number of patients investigated is relatively small and those with (subclinical) thyroid dysfunctions are an even smaller number; hence, it is therefore difficult to draw firm conclusions. Moreover, the present results are derived from patients consulting an Italian Andrology Clinic for couple infertility, and could have different characteristics from the male general population or from those males consulting general practitioners for reasons other than couple infertility. Finally, due to the cross-sectional nature of the study, neither a causality hypothesis nor mechanistic models can be inferred.

WIDER IMPLICATIONS OF THE FINDINGS

Although no associations between TH and sperm parameters were observed, present data support a positive effect of TH on SV size and a permissive role on the ejaculatory machinery, likely through an action on SV and epididymal contractility. This is the first study reporting such evidence. However, in contrast with the view that TH assessment is important for female fertility, our results do not support a systematic evaluation of thyroid function in males of infertile couples. How TH abnormalities impact male fertility needs to be addressed by further studies.

STUDY FUNDING/COMPETING INTERESTS

No funding was received for the study. None of the authors have any conflict of interest to declare.

Hormonal correlations of premature ejaculation

Premature ejaculation is the most frequent male sexual dysfunction, significantly impairing quality of life of both the patient and the partner and affecting up to one-third of men of every age. In the last years, our knowledge about this topic has greatly increased, and studies on the causes and treatments related to ejaculatory disorders have shed a light on previously uncharted territory. Public interest on sexual dysfunctions has likewise increased in the general population: the time lapse between the first symptoms of sexual dysfunction and the seeking of medical advice has been significantly reduced, whereas demand for a treatment has markedly increased. A role of endocrine regulation has been established in all the aspects of male reproduction; however, the endocrine control of ejaculation is not fully understood. Sex steroid, pituitary, and thyroid hormones have all been advocated as potential candidates in the regulation of the ejaculatory process, but exact mechanisms are not clear yet and further studies are required in order to identify potential targets for treatment.

Crossover of the hypothalamic pituitary-adrenal/interrenal, -thyroid, and -gonadal axes in testicular development

Besides the well-known function of thyroid hormones (THs) for regulating metabolism, it has recently been discovered that THs are also involved in testicular development in mammalian and non-mammalian species. THs, in combination with follicle stimulating hormone, lead to androgen synthesis in Danio rerio, which results in the onset of spermatogenesis in the testis, potentially relating the hypothalamic-pituitary-thyroid (HPT) gland to the hypothalamic-pituitary-gonadal (HPG) axes. Furthermore, studies in non-mammalian species have suggested that by stimulating the thyroid-stimulating hormone (TSH), THs can be induced by corticotropin-releasing hormone. This suggests that the hypothalamic-pituitary-adrenal/interrenal gland (HPA) axis might influence the HPT axis. Additionally, it was shown that hormones pertaining to both HPT and HPA could also influence the HPG endocrine axis. For example, high levels of androgens were observed in the testis in Odonthestes bonariensis during a period of stress-induced sex-determination, which suggests that stress hormones influence the gonadal fate toward masculinization. Thus, this review highlights the hormonal interactions observed between the HPT, HPA, and HPG axes using a comparative approach in order to better understand how these endocrine systems could interact with each other to influence the development of testes.

An Update of the International Society of Sexual Medicine's Guidelines for the Diagnosis and Treatment of Premature Ejaculation (PE)

INTRODUCTION

In 2009, the International Society for Sexual Medicine (ISSM) convened a select panel of experts to develop an evidence-based set of guidelines for patients suffering from lifelong premature ejaculation (PE). That document reviewed definitions, etiology, impact on the patient and partner, assessment, and pharmacological, psychological, and combined treatments. It concluded by recognizing the continually evolving nature of clinical research and recommended a subsequent guideline review and revision every fourth year. Consistent with that recommendation, the ISSM organized a second multidisciplinary panel of experts in April 2013, which met for 2 days in Bangalore, India. This manuscript updates the previous guidelines and reports on the recommendations of the panel of experts.

AIM

The aim of this study was to develop clearly worded, practical, evidenced-based recommendations for the diagnosis and treatment of PE for family practice clinicians as well as sexual medicine experts.

METHOD

A comprehensive literature review was performed.

RESULTS

This article contains the report of the second ISSM PE Guidelines Committee. It offers a new unified definition of PE and updates the previous treatment recommendations. Brief assessment procedures are delineated, and validated diagnostic and treatment questionnaires are reviewed. Finally, the best practices treatment recommendations are presented to guide clinicians, both familiar and unfamiliar with PE, in facilitating treatment of their patients.

CONCLUSION

Development of guidelines is an evolutionary process that continually reviews data and incorporates the best new research. We expect that ongoing research will lead to a more complete understanding of the pathophysiology as well as new efficacious and safe treatments for this sexual dysfunction. We again recommend that these guidelines be reevaluated and updated by the ISSM in 4 years. Althof SE, McMahon CG, Waldinger MD, Serefoglu EC, Shindel AW, Adaikan PG, Becher E, Dean J, Giuliano F, Hellstrom WJG, Giraldi A, Glina S, Incrocci L, Jannini E, McCabe M, Parish S, Rowland D, Segraves RT, Sharlip I, and Torres LO. An update of the International Society of Sexual Medicine's guidelines for the diagnosis and treatment of premature ejaculation (PE). Sex Med 2014;2:60-90.

An update of the International Society of Sexual Medicine's guidelines for the diagnosis and treatment of premature ejaculation (PE)

INTRODUCTION

In 2009, the International Society for Sexual Medicine (ISSM) convened a select panel of experts to develop an evidence-based set of guidelines for patients suffering from lifelong premature ejaculation (PE). That document reviewed definitions, etiology, impact on the patient and partner, assessment, and pharmacological, psychological, and combined treatments. It concluded by recognizing the continually evolving nature of clinical research and recommended a subsequent guideline review and revision every fourth year. Consistent with that recommendation, the ISSM organized a second multidisciplinary panel of experts in April 2013, which met for 2 days in Bangalore, India. This manuscript updates the previous guidelines and reports on the recommendations of the panel of experts.

AIM

The aim of this study was to develop clearly worded, practical, evidenced-based recommendations for the diagnosis and treatment of PE for family practice clinicians as well as sexual medicine experts.

METHOD

A comprehensive literature review was performed.

RESULTS

This article contains the report of the second ISSM PE Guidelines Committee. It offers a new unified definition of PE and updates the previous treatment recommendations. Brief assessment procedures are delineated, and validated diagnostic and treatment questionnaires are reviewed. Finally, the best practices treatment recommendations are presented to guide clinicians, both familiar and unfamiliar with PE, in facilitating treatment of their patients.

CONCLUSION

Development of guidelines is an evolutionary process that continually reviews data and incorporates the best new research. We expect that ongoing research will lead to a more complete understanding of the pathophysiology as well as new efficacious and safe treatments for this sexual dysfunction. We again recommend that these guidelines be reevaluated and updated by the ISSM in 4 years.

Platelet-derived growth factor regulation of type-5 phosphodiesterase in human and rat penile smooth muscle cells

INTRODUCTION

Relaxation of cavernous smooth muscle cells (SMCs) is a key component in the control of the erectile mechanism. SMCs can switch their phenotype from a contractile differentiated state to a proliferative and dedifferentiated state in response to a change of local environmental stimuli. Proliferation and contraction are both regulated by the intracellular second messengers cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are degraded by phosphodiesterases (PDEs). The most abundant PDE present in corpora cavernosa is the electrolytic cGMP-specific phosphodiesterase type 5 (PDE5).

AIM

We investigated the cellular localization of PDE5 in in vitro cultured corpora cavernosa cells and the effect of mitogenic stimulation on PDE5 expression.

METHODS

Biochemical ad molecular techniques on cultured SMCs from human and rat penis.

MAIN OUTCOME MEASURES

We studied the ability of the quiescent SMC phenotype vs. the proliferating phenotype in modulation of PDE5 expression.

RESULTS

We demonstrated that PDE5 is localized in the cytoplasm, in the perinuclear area, and in discrete cytoplasmic foci. As previously demonstrated in human myometrial cells, the cytoplasmic foci may correspond to centrosomes. In corpora cavernosa, PDE5 protein levels are strongly regulated by the mitotic activity of the SMCs, as they were increased in quiescent cultures. In contrast, treatment with platelet-derived grow factor (PDGF), one of the most powerful mitogenic factors for SMCs, reduces the expression of PDE5 after 24 hours of treatment.

CONCLUSION

We found that PDGF treatment downregulates PDE5 expression in proliferating SMCs, suggesting that PDE5 may represent one of the markers of the contractile phenotype of the SMCs of corpora cavernosa.

The hormonal control of ejaculation

Hormones regulate all aspects of male reproduction, from sperm production to sexual drive. Although emerging evidence from animal models and small clinical studies in humans clearly point to a role for several hormones in controlling the ejaculatory process, the exact endocrine mechanisms are unclear. Evidence shows that oxytocin is actively involved in regulating orgasm and ejaculation via peripheral, central and spinal mechanisms. Associations between delayed and premature ejaculation with hypothyroidism and hyperthyroidism, respectively, have also been extensively documented. Some models suggest that glucocorticoids are involved in the regulation of the ejaculatory reflex, but corresponding data from human studies are scant. Oestrogens regulate epididymal motility, whereas testosterone can affect the central and peripheral aspects of the ejaculatory process. Overall, the data of the endocrine system in regulating the ejaculatory reflex suggest that widely available endocrine therapies might be effective in treating sexual disorders in these men. Indeed, substantial evidence has documented that treatments of thyroid diseases are able to improve some ejaculatory difficulties.

Thyroid hormones and male sexual function

The role of thyroid hormones in the control of erectile functioning has been only superficially investigated. The aim of the present study was to investigate the association between thyroid and erectile function in two different cohorts of subjects. The first one derives from the European Male Ageing Study (EMAS study), a multicentre survey performed on a sample of 3369 community-dwelling men aged 40-79 years (mean 60 ± 11 years). The second cohort is a consecutive series of 3203 heterosexual male patients (mean age 51.8 ± 13.0 years) attending our Andrology and Sexual Medicine Outpatient Clinic for sexual dysfunction at the University of Florence (UNIFI study). In the EMAS study all subjects were tested for thyroid-stimulating hormone (TSH) and free thyroxine (FT4). Similarly, TSH levels were checked in all patients in the UNIFI study, while FT4 only when TSH resulted outside the reference range. Overt primary hyperthyroidism (reduced TSH and elevated FT4, according to the reference range) was found in 0.3 and 0.2% of EMAS and UNIFI study respectively. In both study cohorts, suppressed TSH levels were associated with erectile dysfunction (ED). Overt hyperthyroidism was associated with an increased risk of severe erectile dysfunction (ED, hazard ratio = 14 and 16 in the EMAS and UNIFI study, respectively; both p < 0.05), after adjusting for confounding factors. These associations were confirmed in nested case-control analyses, comparing subjects with overt hyperthyroidism to age, BMI, smoking status and testosterone-matched controls. Conversely, no association between primary hypothyroidism and ED was observed. In conclusion, erectile function should be evaluated in all individuals with hyperthyroidism. Conversely, assessment of thyroid function cannot be recommended as routine practice in all ED patients.

Hyperthyroidism and erectile dysfunction: a population-based case-control study

Dysthyroidism has been highlighted as a common endocrine disorder associated with erectile dysfunction (ED); however, to date, no large-scale population-based study has investigated the association between hyperthyroidism and ED. This case-control study aimed to explore the association between ED and hyperthyroidism using a population-based data set. In total, 6310 adult patients who received new diagnoses of ED were recruited as cases together with 18 930 matched enrollees with no history of ED who served as controls. Conditional logistic regressions were conducted to explore the association between ED and having been previously diagnosed with hyperthyroidism. In total, 569 (2.3%) of the 25 240 sampled subjects had been diagnosed with hyperthyroidism before the index date; hyperthyroidism was found in 207 (3.3%) cases and 362 (1.90%) controls. After adjusting for potential confounding factors, the odds ratio (OR) of prior hyperthyroidism among cases was 1.64 (95% confidence interval=1.37-1.96, P<0.001) than that of controls. No association was detected between prior hyperthyroidism and ED for the 18-30, 30-39 and >70 age groups. Subjects aged between 60 and 69 years had the highest ORs for prior hyperthyroidism among cases when compared to controls (OR=1.84; 95% confidence interval=1.20-2.84; P<0.001). Our study further confirms the existence of an association between ED and prior hyperthyroidism.

Hormonal causes of male sexual dysfunctions and their management (hyperprolactinemia, thyroid disorders, GH disorders, and DHEA)

INTRODUCTION

Besides hypogonadism, other endocrine disorders have been associated with male sexual dysfunction (MSD).

AIM

To review the role of the pituitary hormone prolactin (PRL), growth hormone (GH), thyroid hormones, and adrenal androgens in MSD.

METHODS

A systematic search of published evidence was performed using Medline (1969 to September 2011). Oxford Centre for Evidence-Based Medicine-Levels of Evidence (March 2009) was applied when possible.

MAIN OUTCOME MEASURES

The most important evidence regarding the role played by PRL, GH, thyroid, and adrenal hormone was reviewed and discussed.

RESULTS

Only severe hyperprolactinemia (>35 ng/mL or 735 mU/L), often related to a pituitary tumor, has a negative impact on sexual function, impairing sexual desire, testosterone production, and, through the latter, erectile function due to a dual effect: mass effect and PRL-induced suppression on gonadotropin secretion. The latter is PRL-level dependent. Emerging evidence indicates that hyperthyroidism is associated with an increased risk of premature ejaculation and might also be associated with erectile dysfunction (ED), whereas hypothyroidism mainly affects sexual desire and impairs the ejaculatory reflex. However, the real incidence of thyroid dysfunction in subjects with sexual problems needs to be evaluated. Prevalence of ED and decreased libido increase in acromegalic patients; however, it is still a matter of debate whether GH excess (acromegaly) may create effects due to a direct overproduction of GH/insulin-like growth factor 1 or because of the pituitary mass effects on gonadotropic cells, resulting in hypogonadism. Finally, although dehydroepiandrosterone (DHEA) and its sulfate have been implicated in a broad range of biological derangements, controlled trials have shown that DHEA administration is not useful for improving male sexual function.

CONCLUSIONS

While the association between hyperprolactinemia and hypoactive sexual desire is well defined, more studies are needed to completely understand the role of other hormones in regulating male sexual functioning.

Investigation of the neural target level of hyperthyroidism in premature ejaculation in a rat model of pharmacologically induced ejaculation

INTRODUCTION

Association between hyperthyroidism and premature ejaculation was demonstrated in clinical studies.

AIM

The aim of this study is to determine the target level of changes on ejaculatory physiology under hyperthyroid states.

METHODS

p-Chloroamphetamine (PCA)-induced pharmacologic ejaculation model with 24 male Wistar rats was used in the study. Subcutaneous injection of L-thyroxine for 14 days was performed to induce hyperthyroidism. At the end of the injection period, thyroid hormone status was evaluated by serum thyroid-stimulating hormone measurements in all rats. At the beginning of the operations, complete spinal transections (tx) at the T8-T9 level were performed to half of the L-thyroxine-injected and control group rats. Thus, experimental groups were constructed as follows: Group 1--control-spinal intact (n=6), group 2-control-spinal tx (n=6), group 3-hyperthyroid-spinal intact (n=6), and group 4-hyperthyroid-spinal tx (n=6). Ejaculatory responses were recorded before and 30 minutes after intraperitoneal administration of 5 mg/kg PCA.

MAIN OUTCOME MEASURES

During the operations, seminal vesicle (SV) catheterization and bulbospongiosus (BS) muscle dissections were performed in all rats to demonstrate SV pressure (SVP) BS electromyographic (EMG) activity changes.

RESULTS

Following PCA administration SVP tonic amplitude, SV phasic contraction (SVPC) frequency, SVPC maximal amplitude, and BS EMG area under curve values were higher in hyperthyroid intact rats than in control intact rats. The time interval between PCA administration and first ejaculation of hyperthyroid intact rats were significantly shorter than control intact rats (261 ± 7.30 seconds vs. 426 ± 49.6 seconds, P=0.008). All of the changes in the ejaculatory parameters that were induced by hyperthyroidism were completely resolved after spinal transections at the T8-T9 level in group 4.

CONCLUSION

In this study, we confirmed the recent data that hyperthyroidism affects both the emission and expulsion phases of ejaculation. The changes that were induced by hyperthyroidism on ejaculatory physiology probably take place in the supraspinal centers above T8 level.