The impact of androgen receptor CAG repeat polymorphism on andropausal symptoms in different serum testosterone levels

Clinical efficiency of combination therapy using testosterone replacement therapy, phosphodiesterase 5 inhibitors and Kampo herbal medicine for eugonadal patients with late-onset hypogonadism syndrome

In the present study, the initial treatment efficiency of combination therapy using testosterone replacement therapy (TRT), herbal medicine and phosphodiesterase 5 inhibitors (PDE5i) in male patients with late-onset hypogonadism (LOH) were assessed. A total of 21 patients were enrolled and after 12 weeks, the clinical efficacy was evaluated based on improvement of LOH symptoms via laboratory parameters and several questionnaires, including the Ageing Males' Symptoms (AMS) scale. The overall AMS scores, as well as the psychological, physical and sexual AMS factors prior to and after treatment in the TRT, testosterone enanthate (T enanthate) monotherapy and T enanthate + PDE5i treatment groups were significantly improved. In the herbal medicine group, only the AMS physiological factors were significantly improved after treatment compared with the baseline. The improvement of the overall AMS scores, as well as the physiological and sexual AMS factors, were significantly negatively correlated with the free testosterone (FT) value prior to treatment. In conclusion, treatment with combination therapy using TRT, herbal medicine and PDE5i improved AMS scores in patients with LOH syndrome. Particularly in patients with LOH syndrome and low FT, the symptoms were significantly improved following combination therapy.

Genetics and erectile dysfunction: leveraging early foundations for new discoveries

There is considerable interest in understanding the genetics of erectile dysfunction (ED). Since early twin studies that suggested a genetic component to ED, multiple candidate gene studies have identified genetic variants that may be associated with ED. Genome-wide association studies (GWAS) have overcome some of the criticism of the candidate gene approach. Two recent GWAS studies have identified loci near SIM1 that may be associated with ED and have renewed interest in the leptin melanocortin signaling pathway. We review the current literature on the genetic basis of ED by highlighting several candidate genes and genetic variants associated with ED.

Androgen receptor gene polymorphism and sexual function in midlife women

PURPOSE

To assess the impact of serum androgen levels and androgen receptor CAG polymorphism on sexual function in 45 healthy midlife women living in a heterosexual relationship.

METHODS

Cross-sectional study [Cantonal Ethics Committee Bern (Ref.-Nr.

KEK-BE

087/13)].

MAIN OUTCOME MEASURES

Association between androgen serum levels, androgen receptor CAG polymorphism and sexual function was assessed by the FSFI-d questionnaire.

RESULTS

In our cohort of healthy, midlife, well-educated, middle-class, mostly postmenopausal women living in a heterosexual satisfying partnership, sexual function was perceived to remain stable or to decline during menopausal transition with sexual desire scoring lowest (FSFI-d 3.3 ± 0.9). Androgen serum levels did not correlate with sexual function. Mean CAG repeat number was 21.6 ± 1.9. There was a highly inverse though non-significant correlation between female sexual function and AR CAG repeat polymorphism with specifically higher numbers of CAG repeats being significantly positively correlated to more frequent or more severe pain during or after sexual intercourse.

CONCLUSION

The AR polymorphism is a non-negligible factor in female sexual function. Future studies on female sexual (dys)function should incorporate its assessment.

Low-Intensity Extracorporeal Shockwave Therapy Can Improve Erectile Function in Patients Who Failed to Respond to Phosphodiesterase Type 5 Inhibitors

Managing patients with erectile dysfunction (ED) who failed to respond to phosphodiesterase type 5 inhibitors (PDE5is) is a challenging task. Recently, low-intensity extracorporeal shockwave therapy (LI-ESWT) was reported to improve ED by enhancing perfusion of the penis. The current study was performed to evaluate whether combined treatment with LI-ESWT and PDE5is can restore erectile function in patients who failed to respond to PDE5is alone. This was an open-label single-arm prospective study. ED patients with an erection hardness score (EHS) ≦2 under a maximal dosage of PDE5is were enrolled. Sociodemographic information and detailed medical history were recorded. LI-ESWT treatment consisted of 3,000 shockwaves once weekly for 12 weeks. All patients continued their regular PDE5is use. The EHS and the 5-item version of the International Index of Erectile Function (IIEF-5) were used to evaluate the change in erectile function 1 and 3 months after LI-ESWT. A total of 52 patients were enrolled. After LI-ESWT treatment, 35 of the 52 patients (67.3%) could achieve an erection hard enough for intercourse (EHS ≧ 3) under PDE5is use at the 1-month follow-up. Initial severity of ED was the only significant predictor of a successful response (EHS1: 35.7% vs. EHS2: 78.9%, p = .005). Thirty-three of the 35 (94.3%) subjects who responded to LI-ESWT could still maintain their erectile function at the 3-month follow-up. LI-ESWT can serve as a salvage therapy for ED patients who failed to respond to PDE5is. Initial severity of ED was an important predictor of a successful response.

Lower SHBG level is associated with higher leptin and lower adiponectin levels as well as metabolic syndrome, independent of testosterone

In addition to testosterone (T), the emerging role of sex hormone-binding globulin (SHBG) in pathogenesis of metabolic syndrome (MetS) has been noted recently. However, reports of associations with serum adipocytokine levels are still limited. Therefore, we conducted this study to evaluate whether serum T and SHBG levels are independent predictors for the risk of MetS that are associated with adiponectin and leptin levels in 614 Taiwanese men over 40 years old collected from a free health screening. Subjects in the lowest quartile of TT and SHBG levels are exposed to a 1.58 and 3.22 times risk of developing MetS, as compared to those in the highest quartile of TT and SHBG levels. However, SHBG retains its significance independent of TT as a MetS risk predictor, but not vice versa. In addition, SHBG was significantly correlated with both adiponectin and leptin levels even after adjusting for TT levels. In conclusion, SHBG served as a major predictor for the risk of MetS and was correlated with serum adiponectin and leptin levels that are independent of T. Further studies are needed to elucidate the true role of SHBG in the pathogenesis of MetS and possible mechanisms associated with serum adiponectin and leptin levels.

UK policy statements on testosterone deficiency

To address widespread media and scientific concerns over the appropriate treatment of TDS with Testosterone Therapy (T Therapy), the Executive Committee of the British Society for Sexual Medicine developed eight consensus statements, based on current scientific evidence to address these controversial issues. These statements were in no-way designed to replace the published evidence-based guidelines on the subject developed by various professional organisations, but to provide specific answers to several current controversial issues. This review examined evidence from Medline, EMBASE and Cochrane searches on HG, T Therapy and cardiovascular safety from May 2005 to May 2015, which revealed 1714 articles, with 52 clinical trials and 32 placebo-controlled randomised controlled trials. The task force developed the following eight key statements.

Influence of Androgen Receptor Gene CAG and GGC Polymorphisms on Male Sexual Function: A Cross-Sectional Study

Background. No study has assessed the possible involvement of GGC androgen receptor (AR) polymorphism in sexual function. Our aim is to evaluate the association between CAG and GGC AR polymorphisms in this function. Methods. We retrospectively examined eighty-five outpatients. Clinical, biochemical, and genetic parameters were considered. Sexual assessment was performed using the International Index of Erectile Function (IIEF) which evaluates erectile function (EF), orgasmic function (OF), sexual desire (SD), intercourse satisfaction (IS), and overall satisfaction (OS). Results. In the whole sample, CAG repeats were inversely correlated with EF, OF, and total IIEF-15 score, whereas GGC tracts did not show any significant correlation with sexual function. CAG relationship with IIEF items retained significance only in the eugonadal but not in the hypogonadal cohort. On the other hand, GGC tracts were not found to be significantly correlated with IIEF variables in either eugonadal or hypogonadal subjects. In eugonadal subjects, logistic regression pointed out that a higher number of CAG triplets were associated with lower values of EF, OF, SD, OS, and total IIEF independently from other confounders. Conclusions. GGC polymorphism seems not to exert any influence on sexual function, whereas CAG polymorphism appears to affect sexual parameters only in eugonadal subjects.

Bulbocavernosus muscle area measurement: a novel method to assess androgenic activity

Serum testosterone does not correlate with androgen tissue activity, and it is critical to optimize tools to evaluate such activity in males. Ultrasound measurement of bulbocavernosus muscle (BCM) was used to assess the relationship between the number of CAG repeats (CAGn) in the androgen receptor (AR) and the BCM size; the changes in the number of CAGn over age were also evaluated. Transperineal ultrasound measurement of the BCM was also performed. AR CAGn were determined by high performance liquid chromatography, and morning hormone levels were determined using immunoassays. Forty-eight men had CAG repeat analysis. Twenty-five were <30 years of age, mean 23.7 years (s.d. = 3.24) and 23 were >45 years of age, mean 53 years (s.d. = 5.58). The median CAGn was 21 (13-29). BCM area was greater when the number of CAGn were <18 as compared to the number of CAGn >24 (P = 0.04). There was a linear correlation between the number of CAGn and the BCM area R 2 = 16% (P = 0.01). In the 45 to 65-years-old group, a much stronger negative correlation (R 2 = 29%, P = 0.01) was noticed. In the 19 to 29-years-old group, no such correlation was found (R 2 = 4%, P = 0.36). In older men, the number of CAGn increased with age (R 2 = 32%, P = 0.01). The number of CAGn in the AR correlates with the area of the BCM. Ultrasound assessment of the BCM is an effective surrogate to evaluate end-organ activity of androgens. The number of CAGn may increase with age.

The interaction of serum testosterone levels and androgen receptor CAG repeat polymorphism on the risk of erectile dysfunction in aging Taiwanese men

Testosterone has been found to play important roles in men's sexual function. However, the effects of testosterone can be modulated by androgen receptor (AR) CAG repeat polymorphism. It could also contribute to the risk of erectile dysfunction (ED). The aim of this study is to evaluate the interaction of serum testosterone levels and AR CAG repeat polymorphism on the risk of ED in aging Taiwanese men. This cross-sectional data of Taiwanese men older than 40 years were collected from a free health screening held between August 2010 and August 2011 in Kaohsiung city, Taiwan. All participants completed a health questionnaires included five-item version of the International Index of Erectile Function (IIEF-5) and the International Prostate Symptoms Score, received a detailed physical examination and provided 20 cm3 whole blood samples for biochemical and genetic evaluation. The IIEF-5 was used to evaluate ED. Serum albumin, total testosterone (TT), and sex hormone-binding globulin levels were measured. Free testosterone level was calculated. AR gene CAG repeat polymorphism was determined by direct sequencing. Finally, 478 men with the mean age of 55.7 ± 4.8 years were included. When TT levels were above 330 ng/dL, the effect of testosterone level on erectile function seemed to reach a plateau and a significantly negative correlation between AR CAG repeat length and the score of IIEF-5 was found (r = -0.119, p = 0.034). After adjusting for other covariates, the longer AR CAG repeat length was still an independent risk factor for ED in subjects with TT above 330 ng/dL (p = 0.006), but not in TT of 330 ng/dL or below. In conclusion, both serum testosterone levels and AR CAG repeat polymorphism can influence erectile function concomitantly. In subjects with normal TT concentration, those with longer AR CAG repeat lengths have a higher risk of developing ED.

The prevalence and correlates of the positive Androgen Deficiency in the Aging Male (ADAM) questionnaire among psychiatric outpatients: a cross-sectional survey of 176 men in a general hospital in Taiwan

INTRODUCTION

The Androgen Deficiency in the Aging Male (ADAM) questionnaire is widely used to screen for late-onset hypogonadism. The positive response to the ADAM questionnaire (positive ADAM) has been associated with depression and poorer quality of life in a number of studies. It is unclear whether there is any value of the ADAM questionnaire in psychiatric populations. In this study, we aimed to determine the utility of the ADAM questionnaire in a convenient sample of male psychiatric outpatients.

METHODS

One hundred and seventy-six men (mean age: 54.3 years; standard deviation: 10.7 years; range: 40-80 years) completed the ADAM questionnaire, the Hospital Anxiety and Depression Scale (HADS), and the Aging Males' Symptoms (AMS) scale. Anxiety was defined as a HADS anxiety subscore ≥8; depression as a HADS depression subscore ≥8; and moderate/severe impairment of health-related quality of life (HQoL) as AMS ≥37. ADAM, anxiety, and depression was used to model the moderate/severe impairment of HQoL.

RESULTS

One hundred and sixty-four (93%) men had positive ADAM. Positive ADAM was associated with a lower body mass index (P<0.05) and moderate/severe impairment of HQoL (P<0.001), but was not associated with anxiety or depression (P>0.05). Positive ADAM was associated with five symptoms of the AMS scale: "decline of one's feeling of general well-being", "depressive mood", and three sexual symptoms. In regression analysis, positive ADAM was associated with increased risk of moderate/severe impairment of HQoL (unadjusted odds ratio 20.1, 95% confidence interval 3.77-372, P<0.01), which remained significant with covariates of anxiety and depression (adjusted odds ratio 15.6, 95% confidence interval 2.52-309, P<0.05).

CONCLUSION

The ADAM questionnaire can be used to screen the sexual symptoms but not depression/anxiety in male psychiatric outpatients. Positive ADAM may indicate moderate/severe impairment of HQoL.

Influence of CAG Repeat Polymorphism on the Targets of Testosterone Action

In the last decade, ample evidence has demonstrated the growing importance of androgen receptor (AR) CAG repeat polymorphism in andrology. This genetic parameter is able to condition the peripheral effects of testosterone and therefore to influence male sexual function and fertility, cardiovascular risk, body composition, bone metabolism, the risk of prostate and testicular cancer, the psychiatric status, and the onset of neurodegenerative disorders. In this review, we extensively discuss the literature data and identify a role for AR CAG repeat polymorphism in conditioning the systemic testosterone effects. In particular, our main purpose was to provide an updated text able to shed light on the many and often contradictory findings reporting an influence of CAG repeat polymorphism on the targets of testosterone action.

Influence of androgen receptor CAG polymorphism on sexual function recovery after testosterone therapy in late-onset hypogonadism

INTRODUCTION

Androgen receptor (AR) CAG polymorphism has been found to influence sexual function. However, no study has evaluated its potential to condition sexual function recovery after testosterone replacement therapy (TRT) in a large cohort of hypogonadic subjects.

AIM

To evaluate the role of this polymorphism in sexual function improvement after TRT in late-onset hypogonadism (LOH).

METHODS

Seventy-three men affected by LOH were retrospectively considered. Evaluations were performed before TRT started (time 0) and before the sixth undecanoate testosterone injection.

MAIN OUTCOME MEASURES

International Index of Erectile Function (IIEF) questionnaire (erectile function [EF], orgasmic function [OF], sexual desire [SD], intercourse satisfaction [IS], overall satisfaction [OS], and total IIEF-15 score); total and free testosterone and estradiol; AR gene CAG repeat number.

RESULTS

TRT induced a significant increase in total and free testosterone and estradiol. All IIEF domains significantly improved after TRT. AR CAG repeats negatively and significantly correlated with all the variations (Δ-) of sexual function domains, except for Δ-OS. Conversely, Δ-total testosterone was found to be positively and significantly correlated with sexual function domain variations, except for Δ-IS and Δ-OS. Δ-estradiol did not correlate significantly with any of the variations of sexual function domains. After inclusion in generalized linear models, the number of AR gene CAG triplets was found to be independently and negatively associated with Δ-EF, Δ-SD, Δ-IS, and Δ-Total IIEF-15 score, whereas Δ-total testosterone was independently and positively associated with Δ-EF, Δ-OF, Δ-SD, and Δ-Total IIEF-15 score. However, after including time 0 total testosterone in the model, AR gene CAG triplets remained independently and negatively associated only with Δ-EF and Δ-Total IIEF-15 score, whereas Δ-total testosterone was independently and positively associated only with Δ-EF.

CONCLUSIONS

Longer length of AR gene CAG repeat tract seems to lower TRT-induced improvement of sexual function in LOH.

Associations between Salivary Testosterone Levels, Androgen-Related Genetic Polymorphisms, and Self-Estimated Ejaculation Latency Time

Introduction

Recently, testosterone (T) has been shown to be associated with premature ejaculation (PE) symptoms in the literature. Furthermore, studies suggest that the etiology of PE is partly under genetic control.

Aim

The aim of this study was to reassess findings suggesting an association between testosterone (T) and a key symptom of PE, ejaculation latency time (ELT), as well as exploratively investigating associations between six androgen-related genetic polymorphisms and ELT.

Materials and Methods

Statistical analyses were performed on a population-based sample of 1,429 Finnish men aged 18–45 years (M = 26.9, SD = 4.7). Genotype information was available for 1,345–1,429 of these (depending on the polymorphism), and salivary T samples were available from 384 men. Two androgen receptor gene-linked, two 5-alpha-reductase type 2-gene-linked, and two sex hormone-binding globuline gene-linked polymorphisms were genotyped.

Main Outcome Measures

Ejaculatory function was assessed using self-reported ELT.

Results

We found no association between salivary T levels and ELT. We found a nominally significant association between a 5-alpha-reductase type 2-gene-linked polymorphism (rs2208532) and ELT, but this association did not remain significant after correction for multiple testing. One single nucleotide polymorphism in the sex hormone-binding globulin gene (rs1799941) moderated (significantly after correction for multiple testing) the association between salivary T and ELT, so that A:A genotype carriers had significantly lower salivary T levels as a function of increasing ELT compared with other genotype groups.

Conclusions

We were unable to find support for the hypothesis suggesting an association between T levels and ELT, possibly because of the low number of phenotypically extreme cases (the sample used in the present study was population based). Our results concerning genetic associations should be interpreted with caution until replication studies have been conducted. Jern P, Westberg L, Ankarberg-Lindgren C, Johansson A, Gunst A, Sandnabba NK, and Santtila P. Associations between salivary testosterone levels, androgen-related genetic polymorphisms, and self-estimated ejaculation latency time. Sex Med 2014;2:107–114.

Commentary: Who is a candidate for testosterone therapy? A synthesis of international expert opinions

INTRODUCTION

Despite increasing use of testosterone therapy (TTh) for men with testosterone deficiency (TD), there remains uncertainty determining who is a candidate for treatment.

AIM

The aim if this study was to report the opinions of international experts on TTh, as initially presented at the meeting of the World Meeting on Sexual Medicine in Chicago, United States in August 2012.

METHODS

Expert responses to questions regarding the diagnosis of TD based on their own clinical and research experience.

RESULTS

All experts emphasized the primacy of symptoms for the diagnosis of TD. Total testosterone (T) thresholds used to identify TD ranged from 350 ng/dL to 400 ng/dL (12-14 nmol/L); however, experts emphasized the diagnostic limitations of this test. Free T was obtained by all, with some valuing this test more than total T for clinical decision making. Only one expert routinely used a screening questionnaire. None used age-adjusted values. Bioavailable T and the free androgen index were not used. Luteinizing hormone (LH) and sex hormone-binding globulin levels were routinely obtained at evaluation. Additional supportive evidence for TD diagnosis included small testicular volume, high androgen receptor CAG repeats, elevated LH, and presence of diabetes or metabolic syndrome. Two T tests were generally obtained but not always required. Some experts did not require morning testing in men 50 years and older. All monitored prostate-specific antigen and hematocrit after initiation of TTh. All but one expert would consider a trial of TTh to a symptomatic man with total T within the normal range. Recent studies suggesting increased cardiovascular risk with T therapy were not found to be credible.

CONCLUSIONS

Determining who is a candidate for TTh requires clinical assessment based on symptoms and signs, with confirmatory laboratory evaluation. These expert opinions differed from some published guidelines by the emphasis on symptoms as paramount, recognition of the limitations of total T as a diagnostic test, and the potential utility of a therapeutic trial in symptomatic cases with normal total T concentrations.

CAG repeat testing of androgen receptor polymorphism: is this necessary for the best clinical management of hypogonadism?

INTRODUCTION

It is controversial whether or not testing the length of the androgen receptor polymorphism in clinical practice is useful for correct diagnosis and treatment of hypogonadism.

AIM

To describe the molecular and clinical implications of testing the length of the androgen receptor polymorphism for treatment of hypogonadism in both male and female subjects.

METHODS

A systematic Medline search was conducted using several terms related to and including the terms "androgen receptor," "CAG-repeat polymorphism," "male hypogonadism," "female hypogonadism," and "neurodegenerative disease."

MAIN OUTCOME MEASURES

Clinical evidence that demonstrates the importance of CAG repeat number investigation in male and female hypogonadism.

RESULTS

A thorough review of the clinical utility of CAG repeat polymorphism investigation in men and women with hypogonadism is presented.

CONCLUSIONS

The role of AR CAG repeat number investigation in hypogonadism (male and female) is not yet established in the clinical practice. In both sexes, a role during clinical management of hormonal replacement therapies may be hypothesized, but the CAG repeat number's relationship with the presence or absence of hypogonadal symptoms remains unclear. Pharmacogenomic investigations of the AR polymorphism may be a future option to tailor testosterone titration individually and to better identify subjects as potentially more or less responsive to treatments; also, investigation may be important to individually predict beneficial and side effects in special subpopulations, specifically, obese men and postmenopausal women.