Mechanisms of action of testosterone--unraveling a Gordian knot

Impaired vascular function among young users of anabolic-androgenic steroids

Supraphysiological doses of anabolic-androgenic steroids (AAS) is popular among recreational weightlifters and bodybuilders due to the performance-enhancing properties but is also associated with adverse cardiovascular effects. The knowledge about how AAS affect the vasculature is limited, although results from previous studies suggest alterations in vasoreactivity and morphology. In the present study we investigate the association between long-term use of AAS and vascular function. Hundred and twenty-three males were included in the study, 56 of them current AAS users and 67 weightlifting controls. Vascular function was evaluated by carotid artery reactivity and flow-mediated dilation. AAS users had significantly reduced carotid artery reactivity (p < 0.001) and flow-mediated dilation (p < 0.001) compared to weightlifting controls. Results from the present study indicate that long-term use of AAS affect the cardiovascular system negatively, measured as reduced carotid artery reactivity and flow-mediated dilation. These findings could partly explain sudden cardiovascular events among young long-term users of AAS.

Current Techniques for the Objective Measures of Erectile Hardness

INTRODUCTION

One of the most discussed topics in the urology provider's office is that of the male penile erection. Moreover, this is also a frequent basis for consultation by primary care practitioners. As such, it is essential that urologists are familiar with the various means by which the male erection may be evaluated.

OBJECTIVES

This article describes several techniques presently available that may serve to objectively quantify the rigidity and hardness of the male erection. These techniques are meant to bolster information gathered from the patient interview and physical examination to better guide patient management.

METHODS

An extensive literature review was performed examining publications in PubMed on this subject, including corresponding contextual literature.

RESULTS

While validated patient questionnaires have been routinely employed, the urologist has many additional means available to uncover the extent of the patient's pathology. Many of these tools are noninvasive techniques that involve virtually no risk to the patient and take advantage of pre-existing physiologic properties of the phallus and its blood supply to estimate corresponding tissue stiffness. Specifically, Virtual Touch Tissue Quantification which precisely quantifies axial and radial rigidity, can provide continuous data on how these forces change over time, thus providing a promising comprehensive assessment.

CONCLUSION

Quantification of the erection allows for the patient and provider to assess response to therapy, aids the surgeon in choice of appropriate procedure, and guides effective patient counseling regarding expectation management. Rohrer GE, Premo H, Lentz AC. Current Techniques for the Objective Measures of Erectile Hardness. Sex Med Rev 2022;XX:XXX-XXX.

Role of shear wave elastography measured in the flaccid state in predicting arteriogenic erectile dysfunction

The gold-standard method for diagnosing arteriogenic erectile dysfunction (AED) is the penile Doppler ultrasonography. We proposed a novel method for predicting AED using ultrasonic shear wave elastography (SWE) considering that the former was invasive and variable. A total of 98 male patients were enrolled in our study, referred for ED between December 2018 and October 2020. For comparison, we also included 42 volunteers from the Healthy Physical Examination Center of our hospital. The Penile Doppler Ultrasonography (PDU) and SWE were performed for all patients with the intracavernosal injection (ICI). We named three groups as AED group, nonvascular ED group and healthy controls group. No statistically significant differences were found among the three groups in terms of demographic and clinical characteristics. There were no significant differences in IIEF-5 between AED and nonvascular ED. A significant (r = 0.642, p < 0.0001) positive correlation between flaccid and erectile SWE was observed. With a cut-off value of 13.45 KPa, the area under curve, specificity, and sensitivity of the SWE values under the flaccid state in distinguishing AED from healthy subjects were 0.867, 0.786 and 0.896 respectively. The SWE value in the flaccid state can distinguish the AED from healthy subjects.

Predictive value of low testosterone concentrations regarding coronary heart disease and mortality in men and women - evidence from the FINRISK97 study

INTRODUCTION

The relevance of low testosterone concentrations for incident coronary heart disease (CHD) and mortality has been discussed in various studies. Here, we evaluate the predictive value of low baseline testosterone levels in a large population-based cohort.

METHODS

We measured the serum levels of testosterone in 7671 subjects (3710 male, 3961 female) of the population-based FINRISK97 study.

RESULTS

The median follow-up (FU) was 13.8 years. During the FU, a total of 779 deaths from any cause, and 395 incident CHD events were recorded. The age-adjusted baseline testosterone levels were similar in subjects suffering incident events during FU and those without incident events during FU (men: 15.80 vs. 17.01 nmol L-1 ; P = 0.69, women: 1.14 vs. 1.15 nmol L-1 ; P = 0.92). Weak correlations of testosterone levels were found with smoking (R = 0.09; P < 0.001), HDL cholesterol levels (R = 0.22, P < 0.001), systolic blood pressure (R = -0.05; P = 0.011), BMI (R = -0.23; P < 0.001) and waist-hip-ratio (R = -0.21; P < 0.001) in men, and with eGFR (R = -0.05; P = 0.009) in women. Kaplan-Meier analyses did not reveal a positive association of testosterone levels with incident CHD or mortality. Accordingly, also in Cox regression analyses, testosterone levels were not predictive for incident CHD or mortality - neither in men (HR 1.02 [95%CI: 0.70-1.51]; P = 0.79 for lowest versus highest quarter regarding CHD and HR 1.06 [95%CI: 0.80-1.39]; P = 0.67 regarding mortality), nor in women (HR 1.13 [95%CI: 0.69-1.85]; P = 0.56 for lowest versus highest quarter regarding CHD and HR 0.99 [95%CI: 0.71-1.39]; P = 0.80 regarding mortality).

CONCLUSIONS

Low levels of testosterone are not predictive regarding future CHD or mortality - neither in men, nor in women.

Testosterone Levels and Type 2 Diabetes-No Correlation with Age, Differential Predictive Value in Men and Women

Most studies reporting on the association of circulating testosterone levels with type 2 diabetes in men are of cross-sectional design. Reports on the relevance of altered testosterone levels in women are scarce. Here, we evaluate the role of low serum testosterone levels for incident diabetes in men and women in a population setting of 7706 subjects (3896 females). During a mean follow up time of 13.8 years, 7.8% developed type 2 diabetes. Significant correlations of testosterone with high density lipoprotein (HDL)-cholesterol (R = 0.21, p < 0.001), body-mass-index (R = −0.23, p < 0.001), and waist-to-hip-ratio (R = −0.21, p < 0.001) were found in men. No correlation was found with age in men; in women, the correlation was negligible (R = 0.04, p = 0.012). In men, low testosterone levels predicted high risk of type 2 diabetes, while in women this relationship was opposite. Men with low testosterone levels showed increased risk of future diabetes (hazard ratio (HR) 2.66, 95% confidence interval (CI) 1.91–3.72, p < 0.001 in basic model; HR 1.56 95%, CI 1.10–2.21, p = 0.003). In women, low testosterone levels indicated lower risk with (HR 0.53, 95% CI 0.37–0.77, p = 0.003), while the association lost significance in the fully adjusted model (HR 0.72, 95% CI 0.49–1.05, p = 0.09). Low levels of testosterone predicted future diabetes in men. A borderline opposite association was found in women.

The weight of fatherhood: identifying mechanisms to explain paternal perinatal weight gain

Men appear to gain weight during the transition to parenthood, and fathers are heavier than non-fathers. Paternal perinatal weight gain may set weight trajectories in midlife and have long-term health implications. Since men do not undergo the physical demands of pregnancy and breastfeeding, the specific mechanisms underlying weight gain in new fathers warrant investigation. This review aims to stimulate research on paternal perinatal weight gain by suggesting testable potential mechanisms that (1) show change across the transition to parenthood and (2) play a role in weight and body composition. We identify seven mechanisms, within three categories: behavioural mechanisms (sleep, physical activity, and diet), hormonal mechanisms (testosterone and cortisol), and psychological mechanisms (depression and stress). We also discuss direct effects of partner pregnancy influences (e.g., 'couvade syndrome') on men's body weight. In presenting each mechanism, we discuss how it may be affected by the transition to parenthood, and then review its role in body composition and weight. Next, we describe bidirectional and interactive effects, discuss timing, and present three broad research questions to propel theoretical development.

Age-specific population centiles for androgen status in men

AIM

The age-specific population profiles in men of circulating testosterone and its two bioactive metabolites dihydrotestosterone (DHT) and estradiol (E2) across the adult lifespan and its determinants are not well described.

OBJECTIVE

Our objective was to deduce smoothed age-specific centiles of circulating testosterone, DHT, and E2 in men using pooled data from population-based studies in three Australian cities from liquid chromatography-mass spectrometry steroid measurements in a single laboratory.

DESIGN, SETTING, AND PARTICIPANTS

We pooled data of 10 904 serum samples (serum testosterone, DHT, E2, age, height, and weight) from observational population-based studies in three major cities across Australia.

MAIN OUTCOME MEASURES

Age-specific smoothed centiles for serum testosterone, DHT, and E2 in men aged 35-100 years were deduced by large sample data analysis methods.

RESULTS

We found that serum testosterone, DHT, and E2 decline gradually from ages 35 onwards with a more marked decline after 80 years of age. Higher weight, BMI, and body surface area as well as shorter stature are associated with reduced serum testosterone, DHT, and E2.

CONCLUSIONS

Among Australian men, there is a gradual progressive population-wide decline in androgen status during male aging until the age of 80 years after which there is a more marked decline. Obesity and short stature are associated with reduced androgen status. Research into the age-related decline in androgen status should focus on the progressive accumulation of age-related comorbidities to better inform optimal clinical trial design.

A new method of measuring the stiffness of corpus cavernosum penis with ShearWave™ Elastography

OBJECTIVE

To evaluate the feasibility of measuring the stiffness of corpus cavernosum penis (CCP) with ShearWave™ Elastography (SWE; SuperSonic Imagine, Aix-en-Provence, France).

METHODS

40 healthy volunteers with ages ranging from 19 to 81 years (mean, 36 years; standard deviation, 17 years) were selected in this study. The ultrafast ultrasound device Aixplorer(®) (SuperSonic Imagine) was used for the research and the probe selected was SuperLinear™ SL15-4 (SuperSonic Imagine). The shear wave stiffness (SWS) of CCP was measured using SWE images. The measurement indexes of SWS included (1) SWS of CCP measured in the transverse section (SWS-T), (2) SWS of CCP measured in the longitudinal section (SWS-L) and (3) mean of SWS-T and SWS-L (SWS-M). The interval between hormone test and SWE examination of each subject was less than 7 days. The paired t-test was used to analyse the differences between SWS-T and SWS-L. The Pearson correlation was used to analyse the correlation of SWS of CCP with age as well as with sex hormone levels.

RESULTS

There was no significant difference between SWS-T and SWS-L (p > 0.05). SWS (SWS-T, SWS-L, SWS-M) was negatively correlated with age and oestradiol value, and SWS (SWS-T, SWS-L, SWS-M) was positively correlated with testosterone value.

CONCLUSION

SWE could serve as a new non-invasive method of evaluating the stiffness of CCP.

ADVANCES IN KNOWLEDGE

It is the first time that we have discussed the feasibility of measuring the stiffness of CCP with SWE and analysed the correlation of SWS of CCP with age as well as with sex hormone levels.

When and when not to use testosterone for palliation in cancer care

Hypogonadism is common throughout the illness trajectory of patients with cancer. About two thirds of male patients with advanced cancer have hypothalamic-pituitary-gonadal dysfunction and low testosterone levels. Chronic inflammation, comorbidities, cachexia, chemotherapy, and medications such as opioids, megestrol acetate, and corticosteroids contribute to primary and secondary hypogonadism. Studies have reported increased symptom burden, diminished quality of life, and poor prognosis associated with low testosterone levels in males with cancer. The Endocrine Society has published clinical practice guidelines for replacing testosterone in symptomatic patients with chronic illness and in patients receiving opioids; however, the role of testosterone therapy specifically in patients with cancer is not addressed. This review explores the potential benefits and limitations of testosterone replacement on the basis of current evidence.

The multiple actions of testosterone in men: nature knows best

In male hormone replacement therapy Finkelstein et al. show that testosterone rather than synthetic "pure" androgens should be prescribed. Testosterone is converted to the superactive androgen dihydrotestosterone and to estradiol, and thus has actions via androgen receptors and both estrogen receptors (ERα, ERβ). Although muscle strength is androgen dependent, estradiol has major physiologic effects in men-on bone, cartilage, and together with androgens, on sexual functioning. Neither dihydrotestosterone nor 'pure' synthetic androgens can be converted to estradiol; those so treated thus risk missing out on the beneficial (and necessary) effects of estrogens in men.