Testosterone deficiency: a risk factor for cardiovascular disease?

Acute effects of testosterone on whole body protein metabolism in hypogonadal and eugonadal conditions: a randomized, placebo-controlled, crossover study

Chronic testosterone (T) substitution and short-term T administration positively affect protein metabolism, however, data on acute effects in humans are sparse. This study aimed to investigate T's acute effects on whole body protein metabolism in hypogonadal and eugonadal conditions. We designed a randomized, double-blind, placebo-controlled, crossover study, including 12 healthy young males. Whole body protein metabolism was evaluated during 1) eugonadism, and after medically induced hypogonadism, with application of a gel on each trial day containing either 2) placebo, 3) T 50 mg, or 4) T 150 mg; under basal (5-h basal period) and insulin-stimulated conditions (3-h clamp). The main outcome measure was a change in net protein balance. The net protein loss was 62% larger in the placebo-treated hypogonadal state compared with the eugonadal state during the basal period (-5.5 ± 3.5 µmol/kg/h vs. -3.4 ± 1.2 µmol/kg/h, P = 0.038), but not during the clamp (P = 0.06). Also, hypogonadism resulted in a 25% increase in whole body urea flux (P = 0.006). However, T did not result in any significant changes in protein breakdown, synthesis, or net balance during either the basal period or clamp (all P > 0.05). Protein breakdown was reduced during clamp compared with the basal period regardless of gonadal status or T exposure (all P ≤ 0.001). In conclusion, the application of transdermal T did not counteract the negative effects of hypogonadism with no effects on protein metabolism within 5 h of administration. Insulin (during clamp) mitigated the effects of hypogonadism. This study is the first to investigate acute protein metabolic effects of T in hypogonadal men.NEW & NOTEWORTHY In a model of medically induced hypogonadism in male volunteers, we found increased whole body urea flux and net protein loss as an expected consequence of hypogonadism. Our study demonstrates the novel finding that the application of transdermal testosterone had no acute effects on whole body protein metabolism under eugonadal conditions, nor could it mitigate the hypogonadism-induced changes in protein metabolism. In contrast, insulin (during clamp) mitigated the effects of hypogonadism on protein metabolism.

Identification and characterization of structural variants related to meat quality in pigs using chromosome-level genome assemblies

BACKGROUND

Many studies have been performed to identify various genomic loci and genes associated with the meat quality in pigs. However, the full genetic architecture of the trait still remains unclear in part because of the lack of accurate identification of related structural variations (SVs) which resulted from the shortage of target breeds, the limitations of sequencing data, and the incompleteness of genome assemblies. The recent generation of a new pig breed with superior meat quality, called Nanchukmacdon, and its chromosome-level genome assembly (the NCMD assembly) has provided new opportunities.

RESULTS

By applying assembly-based SV calling approaches to various genome assemblies of pigs including Nanchukmacdon, the impact of SVs on meat quality was investigated. Especially, by checking the commonality of SVs with other pig breeds, a total of 13,819 Nanchukmacdon-specific SVs (NSVs) were identified, which have a potential effect on the unique meat quality of Nanchukmacdon. The regulatory potentials of NSVs for the expression of nearby genes were further examined using transcriptome- and epigenome-based analyses in different tissues.

CONCLUSIONS

Whole-genome comparisons based on chromosome-level genome assemblies have led to the discovery of SVs affecting meat quality in pigs, and their regulatory potentials were analyzed. The identified NSVs will provide new insights regarding genetic architectures underlying the meat quality in pigs. Finally, this study confirms the utility of chromosome-level genome assemblies and multi-omics analysis to enhance the understanding of unique phenotypes.

ATP10A deficiency results in male-specific infertility in mice

Over 8% of couples worldwide are affected by infertility and nearly half of these cases are due to male-specific issues where the underlying cause is often unknown. Therefore, discovery of new genetic factors contributing to male-specific infertility in model organisms can enhance our understanding of the etiology of this disorder. Here we show that murine ATP10A, a phospholipid flippase, is highly expressed in male reproductive organs, specifically the testes and vas deferens. Therefore, we tested the influence of ATP10A on reproduction by examining fertility of Atp10A knockout mice. Our findings reveal that Atp10A deficiency leads to male-specific infertility, but does not perturb fertility in the females. The Atp10A deficient male mice exhibit smaller testes, reduced sperm count (oligozoospermia) and lower sperm motility (asthenozoospermia). Additionally, Atp10A deficient mice display testes and vas deferens histopathological abnormalities, as well as altered total and relative amounts of hormones associated with the hypothalamic-pituitary-gonadal axis. Surprisingly, circulating testosterone is elevated 2-fold in the Atp10A knockout mice while luteinizing hormone, follicle stimulating hormone, and inhibin B levels were not significantly different from WT littermates. The knockout mice also exhibit elevated levels of gonadotropin receptors and alterations to ERK, p38 MAPK, Akt, and cPLA2-dependent signaling in the testes. Atp10A was knocked out in the C57BL/6J background, which also carries an inactivating nonsense mutation in the closely related lipid flippase, Atp10D. We have corrected the Atp10D nonsense mutation using CRISPR/Cas9 and determined that loss of Atp10A alone is sufficient to cause infertility in male mice. Collectively, these findings highlight the critical role of ATP10A in male fertility in mice and provide valuable insights into the underlying molecular mechanisms.

Associations of Serum Testosterone and Sex Hormone-binding Globulin With Incident Arrhythmias in Men From UK Biobank

CONTEXT

Sex hormones have been identified as cardiovascular risk factors, whereas the relationship between sex hormones and the risk of arrhythmias in men has not yet been well studied in the prospective cohort study.

OBJECTIVE

To analyze associations of serum testosterone and SHBG concentrations and calculate free testosterone (cFT) with arrhythmias in men.

METHODS

Sex hormones were measured at baseline from UK Biobank. Main outcomes were incidence of atrial fibrillation/flutter (AF), ventricular arrhythmia (VA), and bradyarrhythmia (BA).

RESULTS

Of 173 498 men (aged 37-73 years, followed for 11 years), 11 368 had incident AF, 1646 had incident VA, and 4788 had incident BA. Compared with the third quartiles, the lowest category of serum testosterone was associated with increased risks of AF (hazard ratio [HR], 1.06; 95% CI, 1.00-1.12) and BA (HR, 1.11; 95% CI, 1.02-1.20) after multivariable adjustment, but no VA. Likewise, similar associations were found between cFT values and AF and BA events. Furthermore, higher levels of cFT were associated with increased risks of AF (HR, 1.07; 95% CI, 1.02-1.13) and VA (HR, 1.18; 95% CI, 1.01-1.37). Higher SHBG concentrations were associated with increased risks of AF (HR, 1.44; 95% CI, 1.34-1.54), VA (HR, 1.27; 95% CI, 1.07-1.52), and BA (HR, 1.17; 95% CI ,1.05-1.29).

CONCLUSIONS

Lower levels of testosterone and cFT were associated with increased risk of AF and BA. Higher cFT levels were associated with increased risk of AF and VA. Higher SHBG levels were associated with increased risk of AF, VA, and BA.

A phase III, single-arm, 6-month trial of a wide-dose range oral testosterone undecanoate product

Background

Oral testosterone undecanoate (TU) formulations may provide effective, safe, and easily titratable testosterone replacement therapy.

Objective

Demonstrate efficacy and safety of a novel oral TU formulation.

Design

An open-label, single-arm, multi-center trial treated 155 hypogonadal men for 180 days. Treatment began at 200 mg TU twice daily with meals; doses were titrated over two 28-day cycles to between 100 and 800 mg TU daily, measuring average testosterone (T Cavg) after 90 days. Ambulatory blood pressure monitoring (ABPM) occurred at baseline, 120, and 180 days.

Methods

Titrations used a randomized blood sample taken 3-, 4-, or 5-h post-morning dose. Outcomes used sodium fluoride/ethylenediaminetetraacetate plasma testosterone (T) values; serum results were also reported. Blood pressure (ABPM and in-clinic) was evaluated for change from baseline.

Results

After titration, 87.8% of KYZATREX™ treated participants (worse-case scenario) and 96.1% of 90-day completers achieved eugonadal mean plasma T values. Serum T Cavg was 452 ng/dL and maximum T concentrations (T Cmax) met all FDA criteria. Participant eugonadal percentages were comparable across subgroups for age, weight, and body mass index. Diet had no effect on participant eugonadal percentages. KYZATREX was well tolerated, with no drug-related serious adverse events (SAE) and one adverse drug reaction (hypertension) observed in 2% or more of participants. Systolic ambulatory blood pressure increased 1.7 mmHg (95% confidence interval: 0.3-3.1). At baseline, 36% of 155 participants were receiving anti-hypertensive medication and 22% were diabetic. No dose increases occurred in existing anti-hypertensive medication; five participants (3.2%) started anti-hypertensive medication.

Conclusion

KYZATREX provided safe and effective testosterone levels within the normal range in hypogonadal male study participants.

Clinical trial registration

URL: https://clinicaltrials.gov/ unique identifier NCT04467697, conducted under NCT03198728. Post-completion, clinicaltrials.gov requested creation of the separate NCT04467697 identifier. All subjects were recruited under NCT03198728.

Efficacy of multidisciplinary interventions in preventing metabolic syndrome and improving body composition in prostate cancer patients treated with androgen deprivation therapy: A systematic review and meta-analysis

BACKGROUND

Exercise is known to reduce adverse side effects of androgen-deprivation therapy (ADT) on quality of life, bone health and fatigue for prostate cancer (PCa) patients. We conducted a systematic review with meta-analysis to evaluate the effect of multidisciplinary interventions on body composition and metabolic syndrome (MetS) in ADT-treated PCa patients.

METHODS

A systematic review and meta-analysis were conducted based on searches of EMBASE, MEDLINE, CENTRAL and Scopus databases from inception to March 2023. Participants included ADT-treated PCa patients who received multidisciplinary interventions including exercise, diet, nutrition, pharmacotherapy, bariatric surgery, or psychological/behavioural therapy. Primary outcomes were changes in body composition and MetS, with prostate-specific antigen (PSA) as a secondary outcome. After meta-analysis, results were reported in mean difference, 95% confidence interval and p-value, with forest plots. Additionally, we conducted subgroup analyses to compare the effect of different interventions.

RESULTS

Thirty-three articles met the eligibility criteria out of 1443 articles and 28 studies were included in meta-analysis. Of 33 studies, 17 included exercise-only interventions and 10 included exercise + diet/nutrition interventions, but no studies included diet/nutrition-only interventions. All studies employed multidisciplinary approaches in developing or delivering the interventions. Most studies (85%) had low-moderate risk of bias, thus providing good evidence to this review. Overall, interventions had a positive effect on body composition measures; lean mass (LM):0.82 kg (95% CI:0.47,1.17;p < 0.00001), body fat mass (BFM):-0.68 kg (95% CI:-1.12,-0.24;p = 0.002), fat-free mass:0.75 kg (95% CI:0.14,1.37;p = 0.02) and body fat percentage (BFP):-0.99% (95% CI:-1.29,-0.68;p < 0.00001), as well as on MetS; waist circumference:-1.95 cm (95% CI:-3.10,-0.79;p = 0.0009), systolic blood pressure:-3.43 mmHg (95% CI:-6.36,-0.50;p = 0.02) and diastolic blood pressure:-2.48 mmHg (95% CI:-4.19,-0.76;p = 0.005). Subgroup-analyses showed that a combined approach including exercise + diet/nutrition was most effective in improving BFP, WC, SBP and DBP whereas exercise was more effective in improving LM and BFM.

CONCLUSIONS

In ADT-treated PCa patients, multidisciplinary interventions, especially those combining exercise and diet/nutrition, can improve body composition and metabolic health.

Testosterone and aging male, a perspective from a developing country

PURPOSE

Hypogonadism is associated with a wide range of physical and psychological symptoms that can affect the overall health of men. However, in a developing country, there are several imposing challenges in the diagnosis and treatment of hypogonadism, including a lack of awareness and understanding of the condition among healthcare providers and patients, limited resources and the high cost of treatment. This review aimed to examine the potential benefits and risks of testosterone replacement therapy (TRT) and provides a perspective of a developing country on the topic.

MATERIALS AND METHODS

A comprehensive literature review was conducted to gather relevant information on the impact of testosterone deficiency on ageing males and the effectiveness of TRT for treating hypogonadism. Published peer-reviewed articles were analyzed to evaluate the benefits and risks of TRT. Additionally, the unique challenges faced in the diagnosis and treatment of hypogonadism in a developing country were considered.

RESULTS

Testosterone replacement therapy has been shown to be an effective treatment for hypogonadism, particularly in symptomatic men with low testosterone levels. It offers potential benefits such as improvements in symptoms and overall quality of life. However, there are associated risks and side effects that need to be considered. In a developing country, challenges such as limited awareness and understanding of hypogonadism, resource constraints, and high treatment costs pose additional barriers to accessing TRT and comprehensive care.

CONCLUSION

In conclusion, TRT holds promise as a treatment for hypogonadism, but its implementation and accessibility face significant challenges in a developing country. Addressing these challenges, including raising awareness, allocating resources, and finding cost-effective solutions, is crucial for ensuring that men with hypogonadism in such settings receive appropriate diagnosis and treatment. Further research and efforts are needed to improve the management of hypogonadism in developing countries and optimize the potential benefits of TRT for affected individuals.

Clinical Pathway for Coronary Atherosclerosis in Patients Without Conventional Modifiable Risk Factors: JACC State-of-the-Art Review

Reducing the incidence and prevalence of standard modifiable cardiovascular risk factors (SMuRFs) is critical to tackling the global burden of coronary artery disease (CAD). However, a substantial number of individuals develop coronary atherosclerosis despite no SMuRFs. SMuRFless patients presenting with myocardial infarction have been observed to have an unexpected higher early mortality compared to their counterparts with at least 1 SMuRF. Evidence for optimal management of these patients is lacking. We assembled an international, multidisciplinary team to develop an evidence-based clinical pathway for SMuRFless CAD patients. A modified Delphi method was applied. The resulting pathway confirms underlying atherosclerosis and true SMuRFless status, ensures evidence-based secondary prevention, and considers additional tests and interventions for less typical contributors. This dedicated pathway for a previously overlooked CAD population, with an accompanying registry, aims to improve outcomes through enhanced adherence to evidence-based secondary prevention and additional diagnosis of modifiable risk factors observed.

Male sex hormones, aging, and inflammation

Adequate levels of androgens (eugonadism), and specifically testosterone, are vital compounds for male quality of life, longevity, and positive health outcomes. Testosterone exerts its effects by binding to the androgen receptor, which is expressed in numerous tissues throughout the body. Significant research has been conducted on the impact of this steroid hormone on skeletal, muscle and adipose tissues and on the cardiovascular, immune, and nervous systems. Testosterone levels have also been studied in relation to the impact of diseases, aging, nutrition and the environment on its circulating levels. Conversely, the impact of testosterone on health has also been evaluated with respect to its cardiac and vascular protective effects, body composition, autoimmunity and all-cause mortality. The male aging process results in decreasing testosterone levels over time. The exact mechanisms and impact of these changes in testosterone levels with age on health- and life-span are still not completely clear. Further research is needed to determine the optimal testosterone and androgen levels to protect from chronic age-related conditions such as frailty and osteoporosis.

Androgens and Androgen Receptors as Determinants of Vascular Sex Differences Across the Lifespan

Androgens, including testosterone and its more potent metabolite dihydrotestosterone, exert multiple actions in the body. Physiologically, they play a critical role in male sex development. In addition, they influence vascular function, including arterial vasodilation and mediation of myogenic tone. Androgens are produced from 9 weeks' gestation in the human fetal testis, as well as in small amounts by the adrenal glands. Serum concentrations vary according to age and sex. The vasculature is a target for direct actions of androgens, which bind to various sex hormone receptors expressed in endothelial and vascular smooth muscle cells. Androgens exert both vasoprotective and vasoinjurious effects, depending on multiple factors including sex-specific effects of androgens, heterogeneity of the vascular endothelium, differential expression of androgen and sex hormone receptors in endothelial and vascular smooth muscle cells, and the chronicity of androgen administration. Long-term administration of androgens induces vasoconstriction and influences endothelial permeability, whereas acute administration may have opposite effects. At the cellular level, androgens stimulate endothelial cell production of nitric oxide and inhibit proinflammatory signalling pathways, inducing vasorelaxation and vasoprotection. However, androgens also activate endothelial production of vasoconstrictors and stimulate recruitment of endothelial progenitor cells. In humans, both androgen deficiency and androgen excess are associated with increased cardiovascular morbidity and mortality. This review discusses how androgens modulate vascular sex differences across the lifespan by considering the actions and production of androgens in both sexes and describes how cardiovascular risk is altered as levels of androgens change with aging.

Effect of High-Fructose Diet-Induced Metabolic Syndrome on the Pituitary-Gonadal Axis in Male Rats

Plasma testosterone levels have been found to decrease in older insulin-resistant male patients. Both lower total testosterone levels and a higher incidence of metabolic syndrome have also been reported. The aim of this study was to investigate the effects of high-fructose diet-induced diabetes on both the testosterone release by Leydig cells and the activity of the hypothalamus-pituitary-gonadal (HPG) axis in male rats. Male rats were fed with either standard chow (control group) or a high-fructose diet (fructose-fed group) for 21 weeks. Hyperglycemia, hyperinsulinemia, and hypertension were observed in the fructose-fed group. Moreover, plasma testosterone and LH levels decreased in the fructose-fed group compared to the control group. Sperm motility was also reduced by 15% in the fructose-fed rats. In contrast, the basal release of testosterone from rat Leydig cells was not altered by fructose feeding. Moreover, in vitro studies showed that the testosterone release, in response to different stimulants, including forskolin (an adenylyl cyclase activator, 10^-5 M), 8-Br-cAMP (a permeable analog of cAMP, 10^-5 M), A23187 (a calcium ionophore, 10^-5 M), or 25-hydroxy-cholesterol (water-soluble cholesterol, 10^-5 M), did not significantly differ between the fructose-fed and control groups. Interestingly, the release of testosterone in response to human chorionic gonadotropin (hCG, 0.05 IU/mL) was enhanced by eightfold in the control group, but elevenfold in the fructose-fed group. LH receptor expression in rat Leydig cells was also increased. Moreover, LH secretion from the anterior pituitary was altered in the fructose diet-fed group. These results suggest that fructose diet-fed rats have lower plasma testosterone levels, which can lead to a higher sensitivity of hCG in Leydig cells.

Novel androgen therapies including selective androgen receptor modulators

Male hypogonadism is associated with reduced quality of life and the development of co-morbidities including obesity, diabetes mellitus, and dyslipidaemia. The mainstay of treatment for male hypogonadism is testosterone replacement therapy (TRT). However, TRT has recognised side effects including impaired spermatogenesis and there are concerns regarding its use in men with concurrent cardiovascular disease. Thus, there has been an impetus to develop novel androgen therapies for treating male hypogonadism to mitigate the side effects of TRT. This review will discuss the benefits and adverse effects of TRT, and novel therapies including nasal testosterone, aromatase inhibitors, selective oestrogen receptor modulators, and selective androgen receptor modulators.

Androgens and Non-Genomic vascular responses in hypertension

Arterial hypertension is a global public health concern. In the last few years, the interest in androgen deficiency has been growing, and the association between androgens and high blood pressure (BP) is still controversial. One purpose of this review was to summarize the available findings in order to clarify whether male sex steroid hormones have beneficial or harmful effect on BP. The second purpose was to enhance the recognition of the acute non-genomic sex-independent vasorelaxing effect of androgens. Remarkably, BP variation is expected to be a consequence of the androgen-induced vasorelaxation which reduces systemic BP; hence the in vivo vasodepressor, hypotensive, and antihypertensive responses of androgens were also analyzed. This article reviews the current understanding of the physiological regulation of vascular smooth muscle contractility by androgens. Additionally, it summarizes older and more recent data on androgens, and some of the possible underlying mechanisms of relaxation, structural-functional differences in the androgen molecules, and their designing ability to induce vasorelaxation. The clinical relevance of these findings in terms of designing future therapeutics mainly the 5-reduced metabolite of testosterone, 5β-dihydrotestosterone, is also highlighted. Literature collected through a PubMed database search, as well as our experimental work, was used for the present review.

Does Patient-Applied Testosterone Replacement Therapy Pose Risk for Blood Pressure Elevation? Circadian Medicine Perspectives

We reviewed medication package inserts, US Food and Drug Administration (FDA) reports, and journal publications concerning the 10 nonbiosimilar patient-applied (PA) testosterone (T) replacement therapies (TRTs) for intraday serum T patterning and blood pressure (BP) effects. Blood T concentration is circadian rhythmic in young adult eugonadal males, being highest around awakening and lowest before bedtime. T level and 24 h variation are blunted in primary and secondary hypogonadism. Utilized as recommended, most PA-TRTs achieve nonphysiologic T 24 h patterning. Only Androderm^® , an evening PA transdermal patch, closely replicates the normal T circadian rhythmicity. Accurate determination of risk for BP elevation and hypertension (HTN) by PA-TRTs is difficult due to limitations of office BP measurements (OBPM) and suboptimal methods and endpoints of ambulatory BP monitoring (ABPM). OBPM is subject to "White Coat" pressor effect resulting in unrepresentative BP values plus masked normotension and masked HTN, causing misclassification of approximately 45% of trial participants, both before and during treatment. Change in guideline-recommended diagnostic thresholds over time causes misclassification of an additional approximately 15% of participants. ABPM is improperly incorporated into TRT safety trials. It is done for 24 h rather than preferred 48 h; BP is oversampled during wakefulness, biasing derived 24 h mean values; 24 h mean systolic and diastolic BP (SBP, DBP) are inappropriate primary outcomes, because of not being best predictors of risk for major acute cardiovascular events (MACE); "daytime" and "nighttime" BP means referenced to clock time are reported rather than biologically relevant wake-time and sleep-time BP means; most importantly, asleep SBP mean and dipping, strongest predictors of MACE, are disregarded. © 2022 American Physiological Society. Compr Physiol 12: 1-20, 2022.

Genetic, Molecular, and Cellular Determinants of Sex-Specific Cardiovascular Traits

Despite the well-known sex dimorphism in cardiovascular disease traits, the exact genetic, molecular, and cellular underpinnings of these differences are not well understood. A growing body of evidence currently points at the links between cardiovascular disease traits and the genome, epigenome, transcriptome, and metabolome. However, the sex-specific differences in these links remain largely unstudied due to challenges in bioinformatic methods, inadequate statistical power, analytic costs, and paucity of valid experimental models. This review article provides an overview of the literature on sex differences in genetic architecture, heritability, epigenetic changes, transcriptomic signatures, and metabolomic profiles in relation to cardiovascular disease traits. We also review the literature on the associations between sex hormones and cardiovascular disease traits and discuss the potential mechanisms underlying these associations, focusing on human studies.

The association of new-onset diabetes mellitus and medical therapy for benign prostatic hyperplasia: A population-based study

INTRODUCTION

Benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms are highly prevalent in the aging male. Similarly, the prevalence of metabolic syndrome is increasing worldwide, with mounting evidence that these two common conditions share more than age as a predisposing factor. The objective of this study was to determine if medical management of BPH is associated with an increased risk of new-onset diabetes mellitus (DM) in routine care.

METHODS

This population-based, retrospective cohort study expands on a parent study of linked administrative databases identifying patients diagnosed and treated for BPH between 2005 and 2015. The primary outcome of this secondary analysis was a new diagnosis of DM after the index date of BPH diagnosis. Covariates included age, dyslipidemia, hypertension, and vascular diseases. A Cox proportional hazards regression model was used for inferential statistical analysis.

RESULTS

A total 129 223 men were identified with a BPH diagnosis and no prior history of DM. Of those men, 6390 (5%) were exposed to 5-alpha-reductase inhibitor (5-ARI), 39 592 (31%) exposed to alpha-blocker (AB), and 30 545 (24%) exposed to combination therapy. Compared to those men with no BPH medication use, those exposed to drugs had an increased risk of new DM. Men treated with combination therapy of 5-ARI and AB (hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.25-1.35), 5-ARI monotherapy (HR 1.25, 95% CI 1.17-1.34), or AB monotherapy (HR 1.17, 95% CI 1.13-1.22) all were at higher risk of new DM diagnosis after adjusting for important covariates. When calculating the risk of a new diabetes diagnosis measured from the start of drug exposure, men treated with 5-ARIs had an increased risk of DM compared to AB monotherapy as the reference, with HR 1.12 (95% CI 1.03-1.21) for 5-ARI monotherapy and HR 1.20 (95% CI 1.14-1.25) for combination therapy.

CONCLUSIONS

In this large, long-term, retrospective study of men with a BPH diagnosis in routine practice, the risk of a new diagnosis of DM was greater in patients receiving medical management compared to controls. This modest but significant increased risk was highest in men treated with any 5-ARIs, in combination as well as monotherapy, compared to the ABs.

Testosterone treatment improves liver function and reduces cardiovascular risk: A long-term prospective study

Objectives: To report the association between testosterone treatment in hypogonadal men with hepatic steatosis, non-alcoholic fatty liver disease and cardiovascular disease (CVD). Methods: A prospective study was conducted to assess the physiological and functional performance of the long-term effects of testosterone undecanoate treatment on hepatic steatosis in 496 hypogonadal men. Two groups were studied, the treatment group (T-group) of 312 patients treated with TU 1000 mg every 12 weeks and followed for 8 years, and an untreated control group (C-group) of 184 patients. We evaluated liver functions and Fatty Liver Index (FLI) according to Mayo Clinic parameters and guidelines. Results: The T-group showed a decrease in the FLI (from a mean [SD] of 83.70 [12.15] to 67.12 [19.21]), bilirubin (from a mean [SD] of 1.69 [4.21] to 1.31 [1.91] mg/dL), triglycerides (from a mean [SD] of 254.87 [92.99] to 213.37 [66.91] mg/dL), and gamma-glutamyl-transferase (from a mean [SD] of 39.45 [11.51] to 29.11 [7.68] U/L) over the duration of the study. Other parameters were also reduced in the T-group such as body mass index (from a mean [SD] of 31.59 [4.51] to 29.50 [3.84] kg/m²) and waist circumference (from a mean [SD] of 107.51 [9.95] to 101.86 [9.28] cm). A total of 25 deaths (7.8%) were recorded in the T-group, among them, 11 (44%) were related to CVD. While in the C-group 28 deaths (15.2%) were recorded and all the reported deaths (100%) were related to CVD. Conclusions: The findings suggest that long-term testosterone therapy in hypogonadal men improves liver function. While, the physiological and functional improvements in the liver may be associated with a decrease in CVD-related mortality.

Abbreviations

ALT: alanine transaminase; AR: androgen receptor; AST: aspartate transaminase; BMI: body mass index; CVD: cardiovascular disease; FLI: Fatty Liver Index; γ-GT: gamma-glutamyl-transferase; MetS: metabolic syndrome; LDL: low-density lipoprotein; NAFLD: non-alcoholic fatty liver disease; RCT: randomised controlled trial; T2DM: type II diabetes mellitus; TT: total testosterone; TTh: testosterone therapy; TU: testosterone undecanoate; WC: waist circumference

iTRAQ-based proteomics of testicular interstitial fluid during aging in mice

Advancing age is associated with a decline in fertility and testicular function in males. The testicular interstitial fluid (TIF) bathing the seminiferous tubules and testicular interstitium is considered an important part of the testicular microenvironment. However, the TIF proteome in mice and whether it changes with age remain unclear. This study aimed to map the TIF proteome and identify differentially abundant proteins (DEPs) among young, middle-aged, and old mice using isobaric tags for relative and absolute quantification (iTRAQ) coupled with liquid chromatography-tandem mass spectrometry. A total of 1477 proteins were identified in murine TIF. The abundance of 706 proteins showed a linear change trend with age, of which 360 and 346 proteins increased and decreased, respectively. In addition, 45 age-related DEPs were identified (P < 0.05, with at least 1.2-fold up- or downregulation). Bioinformatic analyses revealed that these proteins were involved in "actin cytoskeleton organization," "intrinsic apoptotic signaling pathway," and "regulation of protein transport." Comparative analysis with relevant proteomes previously reported further revealed the characteristics of mouse TIF proteome. Moreover, two of the age-related DEPs (Fga and Qsox1) were also found to be age-related differentially expressed proteins in human blood plasma and senescence-related secretome of human peritubular myoid cells. Taken together, these findings may represent the foundation for a better understanding of the molecular function of TIF and testicular aging.

Cardiovascular Disease, Hypogonadism and Erectile Dysfunction: Early Detection, Prevention and the Positive Effects of Long-Term Testosterone Treatment: Prospective Observational, Real-Life Data

Purpose

Erectile dysfunction (ED) is associated with testosterone deficiency and is a symptom of functional hypogonadism. A correlation between ED and cardiovascular disease (CVD) has been recognized, and ED has been proposed as an early marker of CVD. However, the relationship between ED and CVD risk in hypogonadism requires clarification and whether testosterone therapy (TTh) can be a beneficial treatment strategy, but long-term data are limited. This study investigates long-term TTh in men with hypogonadism and ED with a history of CVD.

Methods

Seventy-seven patients with a history of CVD and diagnosed with functional hypogonadism and erectile dysfunction (erectile function domain score <21 on the International Index of Erectile Function questionnaire (IIEF questions 1–5)) were enrolled and TTh effects on anthropometric and metabolic parameters investigated for a maximum duration of 12 years. All men received long-acting injections of testosterone undecanoate at 3-monthly intervals. Eight-year data were analysed. Data collection registry started in November 2004 till January 2015.

Results

In hypogonadal men receiving TTh, IIEF increased by 5.4 (p<0.001). Total weight loss was 23.6 ± 0.6 kg after 8 years. HbA1c had declined by an average of 2.0% (P<0.0001). Total cholesterol levels significantly declined following TTh after only 1 year (P<0.0001), and HDL increased from 1.6±0.5 at baseline to 2±0.5 mmol/L following 8 years of TTh (P<0.0001). SBP decreased from 164±14 at baseline to 133±9 mmHg, signifying a reduction of 33±1 mmHg (P<0.0001).

Conclusion

In hypogonadal men with a history of CVD, TTh improves and preserves erectile function over prolonged periods with concurrent sustained improvements in cardiometabolic risk factors. Measuring ED and testosterone status may serve as an important male health indicator predicting subsequent CVD-related events and mortality and TTh may be an effective add-on treatment in secondary prevention of cardiovascular events in hypogonadal men with a history of CVD.

The Interplay between Androgen and Gut Microbiota: Is There a Microbiota-Gut-Testis Axis

The gut microbiota, a large ecosystem interacting with the host, has been shown to affect the health and fitness of the host-microbial superorganism. Increasing evidence suggests that the gut microbiota communicates with distal organs of the host including the brain, liver, and muscle, as well as testis, through various complex mechanisms. So far, we know that the androgen can markedly remodel the gut microbiota and has initiated an interdisciplinary field termed "microgenderome." More recently, the gut microbiota has been found as a major regulator of androgen production and metabolism in turn and even could trespass the blood-testis barrier (BTB) to regulate spermatogenesis, which largely updates the current knowledge on male reproduction. In this review, we provided a brief overview of the context of the gender bias of diseases related to gut microbiota, the sex dimorphism of gut microbiota, and their relationships with androgen. We also summarized the known interaction between the testis and gut microbiota based on published animal studies and tentatively discussed the hypothesis of microbiota-gut-testis axis. Finally, we highlighted the opportunities and challenges underlying the ongoing research. This knowledge may extend our understanding of the role of gut microbiota in male health and microbiota-related diseases.

Reproductive disorders in male rats induced by high-fructose consumption from juvenile age to puberty

There is compelling evidence that a hypercaloric, high-fructose diet can cause metabolic syndrome (MetS) and a whole range of other metabolic changes. In the context of androgen deficiency, MetS in boys merits special attention, but the effects of fructose-rich diet in youth on future male reproductive function are still poorly evidenced. The aim of this study was to address this issue and analyse the effects of high-fructose intake starting from weaning to puberty (postnatal day 23 up to 83) on the reproductive function of male rats. For this purpose juvenile male Wistar rats were divided in two groups: control and the group receiving 10 % fructose solution instead of drinking water. Reproductive function was evaluated in terms of fertility, sperm count, testes/epididymis morphology, and serum sex hormones. The fructose-treated group showed a decrease in testosterone and twofold increase in luteinising and follicle-stimulating hormone levels in the serum. This was accompanied with lower testis/epididymis weights, sperm count, and changed testis/epididymis morphology. Their fertility remained unchanged, but the fertility of females mating with these males diminished. In addition, pre-implantation and post-implantation embryonic death rate rose in these females. Our results have confirmed that high fructose consumption from early age until puberty can impair the reproductive function of male rats, and call for further animal and epidemiological investigation.

Effect of bariatric surgery on endogenous sex hormones and sex hormone-binding globulin levels: a systematic review and meta-analysis

BACKGROUND

Most studies have shown beneficial effect of bariatric surgery (BS) on serum levels of sex hormones.

OBJECTIVE

A systematic review and meta-analysis was conducted to examine the magnitude of possible changes in levels of sex hormones following BS.

SETTINGS

Electronic databases were searched, including PubMed, Scopus, Web of Science, and Embase, for relevant studies.

METHODS

The heterogeneity of the studies was examined by χ² tests and the degree of heterogeneity was estimated using I² statistic.

RESULTS

The results of pooled analyses revealed that BS caused a significant increase in luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), and sex hormone binding globulin (SHBG) levels and conversely, decreased dehydroepiandrosterone (DHEA) and estradiol (E2) levels in males. For females, BS significantly increased LH, FSH, and SHBG levels and conversely, decreased androstenedione (AE), E2 and TT levels. Additionally, the level of progesterone (P), prolactin (PRL), free testosterone (FT) and dehydroepiandrosterone sulfate (DHEA-S) showed no significant changes in patients who had undergone BS.

CONCLUSION

BS changed most sex hormones levels including LH, FSH, TT, SHBG, AE, DHEA, and E2. It seems that BS is able to exert substantial impacts on sex hormones levels and as well as sexual function, however, larger, and more precise trials are required to specifically focus on these claims.

Age-Related Arteriolar Changes With Lipid and Amyloid Deposits in the Gonads of Dogs

Arteriolar lesions with lipid and/or amyloid deposits are frequently detected in canine gonads by routine histopathologic examination; however, they have never been examined in detail. In the present study, a total of 139 testes/epididymides and 200 ovaries from 72 male (4 months to 14 years old) and 105 female (7 months to 16 years old) dogs were examined for arteriolar lesions. Arteriolar lesions were detected in 21 of 72 male dogs (29%) and 54 of 105 female dogs (51%). These lesions were histologically classified into 4 types: "fibromuscular hypertrophy," characterized by thickening of the tunica intima; "focal vasculitis," characterized by mononuclear cell infiltration; "vacuolar change," consisting of lipid accumulation and infiltration of foamy cells; and "hyalinosis," characterized by irregular thickening with amyloid deposits. In the lesions of vacuolar change and hyalinosis, lipid deposition and infiltration of α-SMA-positive cells and Iba-1-positive cells were also observed. Foamy cells and amyloid deposits were immunopositive for apolipoproteins and oxidized low-density lipoprotein-related proteins. These results indicate that vacuolar change is possibly an early stage of atherosclerosis, and that amyloid may deposit as a consequence of the microenvironment associated with atherogenesis. Logistic regression analysis revealed that arteriolar lesions with lipid deposits were associated with age and interstitial cell tumors in male dogs, and with age in female dogs. Aging is likely an important risk factor of arteriolar lesions with lipid deposits of the canine gonads.

Testosterone target therapy: focus on immune response, controversies and clinical implications in patients with COVID-19 infection

The pandemic acute respiratory syndrome coronavirus 2 (SARS-CoV-2) named COVID-19 is causing a severe health emergency, and an individual's hormonal milieu may play an important role in both susceptibility to infection and severity of clinical course. We analyzed the role of testosterone in the immune response, and we hypothesized possible mechanisms to explain the high incidence of COVID-19 infection and a worse clinical course in elderly male patients. Testosterone may impair the immune response, and this effect could explain the greater susceptibility of men to infection. Transmembrane serine protease 2 (TMPRSS2) plays a crucial role in the entry of the virus into the respiratory epithelial cells, leading to COVID-19 disease. It is crucial to emphasize that testosterone levels and chemical castration (e.g. by androgen deprivation therapy for prostate cancer) may have contrasting roles in the phases of COVID-19 infection. Whereas low testosterone levels may be protective against the initial susceptibility (due to a restoration of immunological functions and a block of TMPRSS2), low testosterone may stimulate a worse clinical course in the advanced COVID-19 infection as it could exacerbate or activate the cytokine storm. If testosterone levels play these different roles, it is necessary to carefully identify patients for any indicated testosterone manipulation.

Effect of Metformin on Testosterone Levels in Male Patients With Type 2 Diabetes Mellitus Treated With Insulin

AIM

To explore the chronic effects of metformin on testosterone levels in men with type 2 diabetes mellitus (T2DM).

METHODS

This is a secondary analysis of a real-world study evaluating the efficacy and safety of premixed insulin treatment in patients with T2DM via 3-month intermittent flash glucose monitoring. Male patients aged 18-60 who were using metformin during the 3-month study period were included as the metformin group. The control group included males without metformin therapy by propensity score matching analysis with age as a covariate. Testosterone levels were measured at baseline and after 3-month treatment.

RESULTS

After 3-month treatment, the control group had higher levels of total testosterone, free and bioavailable testosterone than those at baseline (P<0.05). Compared with the control group, the change of total (-0.82 ± 0.59 vs. 0.99 ± 0.59 nmol/L) and bioavailable (-0.13 ± 0.16 vs. 0.36 ± 0.16 nmol/L) testosterone levels in the metformin group significantly decreased (P=0.036 and 0.029, respectively). In Glycated Albumin (GA) improved subgroup, the TT, FT, and Bio-T levels in the control subgroup were higher than their baseline levels (P < 0.05). Compared with the metformin subgroup, TT level in the control subgroup also increased significantly (P=0.044). In GA unimproved subgroup, the change of TT level in the metformin subgroup was significantly lower than that in the control subgroup (P=0.040).

CONCLUSION

In men with T2DM, 3-month metformin therapy can reduce testosterone levels, and counteract the testosterone elevation that accompanied with the improvement of blood glucose.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov/ct2/show/NCT04847219?term=04847219&draw=2&rank=1.

Long-term testosterone therapy improves liver parameters and steatosis in hypogonadal men: a prospective controlled registry study

Non-alcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease (CVD) and both are prevalent in men with testosterone deficiency. Long-term effects of testosterone therapy (TTh) on NAFLD are not well studied. This observational, prospective, cumulative registry study assesses long-term effects of testosterone undecanoate (TU) on hepatic physiology and function in 505 hypogonadal men (T levels ≤350 ng/dL). Three hundred and twenty one men received TU 1000 mg/12 weeks for up to 12 years following an initial 6-week interval (T-group), while 184 who opted against TTh served as controls (C-group). T-group patients exhibited decreased fatty liver index (FLI, calculated according to Mayo Clinic guidelines) (83.6 ± 12.08 to 66.91 ± 19.38), γ-GT (39.31 ± 11.62 to 28.95 ± 7.57 U/L), bilirubin (1.64 ± 4.13 to 1.21 ± 1.89 mg/dL) and triglycerides (252.35 ± 90.99 to 213 ± 65.91 mg/dL) over 12 years. Waist circumference and body mass index were also reduced in the T-group (107.17 ± 9.64 to 100.34 ± 9.03 cm and 31.51 ± 4.32 to 29.03 ± 3.77 kg/m²). There were 25 deaths (7.8%) in the T-group of which 11 (44%) were cardiovascular related. In contrast, 28 patients (15.2%) died in C-group, and all deaths (100%) were attributed to CVD. These data suggest that long-term TTh improves hepatic steatosis and liver function in hypogonadal men. Improvements in liver function may have contributed to reduced CVD-related mortality.

Androgen receptor-reduced sensitivity is associated with increased mortality and poorer glycaemia in men with type 2 diabetes mellitus: a prospective cohort study

Introduction

Hypogonadism is associated with poorer glycaemic outcomes/increased all-cause and cardiovascular morbidity/mortality in type 2 diabetes mellitus (T2DM). Increasing CAG repeat number within exon-1 of the androgen receptor (AR) gene is associated with increased AR resistance/insulin resistance.

Methods

We determined in a long-term 14-year follow-up cohort of 423 T2DM Caucasian men, the association between baseline androgen status/CAG repeat number (by PCR then Sequenom sequencing) and metabolic/cardiovascular outcomes.

Results

Metabolic outcomes: Lower total testosterone was associated with higher BMI (kg/m²) at 14-year-follow-up: regression coefficient -0.30 (95% confidence interval -0.445 to -0.157), P = 0.0001. The range of CAG repeat number was 9-29 repeats. Higher CAG repeat number in exon-1 of the AR gene was associated with higher follow-up HbA1c2016 - each unit increase in CAG repeat-associated with an increment of 0.1% in HbA1C2016 (P = 0.04), independent of baseline testosterone. Cardiovascular outcomes and mortality: At an average of 14-year-follow-up, 55.8% of hypogonadal men had died vs 36.1% of eugonadal men (P = 0.001). There was a 'u' shaped relation between number of CAG repeats and mortality. Twenty-one CAG repeats were associated with an up to nearly 50% lower mortality rate than <21 CAG repeats and >21 CAG repeats - independent of baseline testosterone level.

Conclusion

A higher number of CAG repeats at the AR gene associates with higher future HbA1c. There was a 'u' shaped relation between CAG repeat number and mortality rate. Determination of CAG repeat number may become part of assessment of androgen status/its consequences for men with T2DM.

Testosterone deficiency caused by castration increases adiposity in male rats in a tissue-specific and diet-dependent manner

Background

Testosterone deficiency in men is clinically associated with the development of metabolic syndrome, which manifests as obesity, hepatic steatosis, and type-2 diabetes. We investigated the effects of castration-induced testosterone deficiency on body adiposity and the expression of genes related to lipid metabolism and glucose uptake and androgen signaling in male rats fed a normal diet (ND) or a high-fat diet (HFD).

Methods

Changes in lipid and glucose metabolism and androgen signaling were investigated at physiological and molecular levels in the muscle, liver, and adipose tissues of non-castrated and castrated rats under ND or HFD feeding.

Results

Castration-induced testosterone deficiency predisposed animals on ND to early development of fatty liver by activating fatty acid (FA) synthesis, whereas HFD activated hepatic FA uptake CD36 expression, leading to the development of hepatic steatosis. In rats fed ND, castration induced muscle fat accumulation by activating CD36 expression. In the subcutaneous fat of ND-fed rats, castration increased adiposity and the expression of FA synthesis-related genes, but it decreased glucose transporter gene expression. In the abdominal fat of rats fed ND, castration increased adiposity by upregulating FA synthesis-related genes, and HFD promoted adiposity by inducing FA uptake, glucose transporter, and FA synthesis-related gene expression. In rats fed ND, castration decreased body growth and muscle weight and downregulated the expression of genes androgen signaling in the longissimus dorsi muscle.

Conclusions

Testosterone deficiency increases adiposity in a tissue-specific and diet-dependent manner. Testosterone deficiency decreases body and muscle weights and downregulates androgen signaling.

Testosterone replacement therapy in men who conceived with intracytoplasmic sperm injection: nationwide register study

OBJECTIVES

Male hypogonadism is associated with higher risk of co-morbidity and premature mortality. It is, therefore, of utmost importance to identify young men who are at the highest risk of testosterone deficiency and who may benefit from preventive measures. In this context, infertile men constitute a high-risk group. The extent of testosterone replacement therapy (TRT) among infertile men, defined as men who have to undergo assisted reproduction for fatherhood, is currently unknown. Therefore, we evaluated the pattern of prescription of TRT in the years following child conception among men who have fathered children with the help of intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF).

DESIGN

By sourcing data from national population registries, hazard ratio (HR) for subsequent TRT was assessed for IVF and ICSI-treated men and compared to those who conceived spontaneously with age Cox regression analysis adjusted for age, educational level and previous intake of medicines for metabolic diseases.

RESULTS

ICSI and IVF fathers had increased incidence of newly prescribed TRT compared to fathers conceiving spontaneously (ICSI: HR = 3.81, 95% CI = 3.09-4.69, P < 0.001; IVF: HR = 1.54, 95% CI = 1.15-2.05, P = 0.003). After adjustment for prescription of medication for one or more components of the MetS prior to TRT, the risk estimates attenuated but remained robust both for ICSI-treated (HR = 3.17 (95% CI: 2.56-3.9) and IVF-treated men (HR = 1.06 (95% CI: 1.05-1.07).

CONCLUSION

Men who have to utilise powerful techniques, such as ICSI for fathering children, may be at risk for testosterone deficiency. Routine endocrine evaluation of men seeking fertility treatment is hence warranted.

Sexual dysfunction and central obesity in patients with first episode psychosis

Background

In recent years the association between sexual dysfunction (SD) and obesity in the general population has drawn major attention. Although sexual dysfunction is common in psychosis, its relationship with weight gain and obesity remains unclear.

Aims

To investigate the association between sexual dysfunction and obesity in a cohort of patients with first episode psychosis.

Method

Sexual function was assessed in a cohort of patients with first episode psychosis using the Sexual Function Questionnaire (SFQ). Anthropometric measures, including weight, BMI, waist, waist–hip ratio were investigated. Additionally, leptin and testosterone were investigated in male patients.

Results

A total of 116 patients (61 males and 55 females) were included. Of these 59% of males and 67.3% of females showed sexual dysfunction (SD) according to the SFQ. In males, higher SFQ scores were significantly correlated with higher BMI (Std. β = 0.36, P = 0.01), higher leptin levels (Std. β = 0.34, P = 0.02), higher waist–hip ratio (Std. β = 0.32, P = 0.04) and lower testosterone levels (Std. β = −0.44, P = 0.002). In contrast, in females, SFQ scores were not associated with any of these factors.

Conclusions

While sexual dysfunction is present in both female and male patients with their first episode of psychosis, only in males is sexual dysfunction associated with increased BMI and waist–hip ratio. The association between SD, BMI, low levels of testosterone and high levels of leptin suggest that policies that lead to healthier diets and more active lifestyles can be beneficial at least, to male patients.

The Interplay between Vascular Function and Sexual Health in Prostate Cancer: The Potential Benefits of Exercise Training

Prostate cancer and its associated treatments can cause significant and lasting morbidities, such as cardiovascular and sexual dysfunctions. Various interventions have attempted to prevent or mitigate these dysfunctions. This review summarises the available evidence on the effects of exercise training on markers of cardiovascular disease (as assessed via vascular health outcomes) and sexual health in this prevalent cancer population. Current studies predominantly report blood pressure outcomes as a marker of vascular health, as well as various questionnaires assessing sexual health parameters, in men on active treatment (i.e., hormone or radiation therapies) or post-treatment. Preliminary evidence suggests that exercise interventions may elicit improvements in sexual function, but not blood pressure, in these populations. Future studies in more advanced and varied prostate cancer populations (i.e., those on chemotherapies or immunotherapies, or undergoing active surveillance) are required to ascertain the duration, intensity and frequency of exercise that optimises the effects of exercise training on cardiovascular and sexual dysfunctions (and their relationship) in men during and following treatment for prostate cancer.

Undernutrition and hyperandrogenism during pregnancy: Role in programming of cardiovascular disease and infertility

Maternal nutritional status programs the development of several systems in female offspring, with effects that depend on the severity, duration, and window of development when the nutritional perturbation is imposed. On the basis of the developmental origins of health and disease concept, we hypothesize that gestational low caloric intake may induce maternal subclinical hyperandrogenism during early pregnancy and compromise cardiovascular health and fertility in the female offspring. To examine this possibility, a literature search for human and animal studies was conducted using two electronic databases, PubMed and Cochrane until April 2019 to address the following questions: (a) Do androgens have a developmental role in cardiovascular and ovarian development? (b) Is excess maternal testosterone linked to cardiovascular disease and infertility? and (c) Could early pregnancy undernutrition enhance maternal androgen production and compromise health and fertility in female offspring? The observations reviewed, establish a potential causative link between maternal undernutrition and subclinical hyperandrogenism with hypertension and reduced ovarian reserve in the progeny. Further studies in appropriate models are needed to better understand whether low energy intake and subclinical maternal hyperandrogenism during early pregnancy can negatively affect the health of the female offspring.

Male hypogonadism: 14-year prospective outcome in 550 men with type 2 diabetes

INTRODUCTION

Hypogonadism is more prevalent in men with type 2 diabetes (T2DM) (25%-40%) than in men without T2DM. Hypogonadism has been associated with poorer glycaemic outcomes and increased cardiovascular morbidity/mortality. We report a 14-year follow-up study to evaluate the influence of baseline testosterone level on T2DM outcomes.

RESEARCH DESIGN AND METHODS

A total of 550 men with T2DM underwent baseline total testosterone and dihydrotestosterone measurement by tandem mass spectrometry. Mean age of the men was 59.7 ± 12 (mean ± SD) years. Sex hormone-binding globulin (SHBG) was measured and free testosterone estimated. Patients were followed up between 2002 and 2016. Mean follow-up period was 12.2 ± 4 years using the Salford (UK) Integrated Health Records system.

RESULTS

Mean baseline total testosterone was 13.7 ± 5.8 nmol/L, and mean free testosterone was 245.7 ± 88.0 pmol/L. Mean for low total testosterone (<10 nmol/L) was 7.6 ± 2.0 nmol/L (n = 154) and 142 men had a free testosterone <190 pmol/L. During the 14-year duration follow-up, 22% of men experienced a myocardial infarction, 18% experienced a stroke, 11% developed angina, 14% underwent coronary revascularization. About 38% of the men initially recruited died. A lower total testosterone was associated with a higher body mass index (kg/m2) at follow-up: regression coefficient -0.30 (95% CI -0.445 to -0.157), P = 0.0001. The mortality rate was higher in patients with lower total testosterone compared to normal baseline total testosterone (5.0% vs 2.8% per year, P < 0.0001). A similar phenomenon was seen for dihydrotestosterone (4.3% vs 2.9% per year, P = 0.002) for normal vs low dihydrotestosterone) and for lower SHBG. Over the whole follow-up period 36.1% (143/396), men with normal baseline testosterone died vs 55.8% (86/154) of hypogonadal men at baseline. In Cox regression, the age-adjusted hazard ratio (HR) for higher mortality associated with low total testosterone was 1.54 (95% CI: 1.2-2.0, P < 0.002), corresponding to a 3.2 year reduced life expectancy for hypogonadal T2DM men.

CONCLUSION

Low testosterone and dihydrotestosterone levels are associated with higher all-cause mortality in T2DM men. Hypogonadal men with T2DM should be considered as very high risk for cardiovascular events/death.

Potential associations of circulating growth differentiation factor-15 with sex hormones in male patients with coronary artery disease

This study aimed to explore the association between growth differentiation factor-15 (GDF-15), a stress-induced factor, and sex hormones in male patients with coronary artery disease (CAD). In this study, we recruited 253 male patients with CAD and 205 male controls. Patients were divided into three groups in accordance with GDF-15 tertiles. Serum levels of GDF-15, testosterone, estradiol and other biochemical variables were measured. Serum levels of GDF-15 were significantly increased and serum testosterone and testosterone/estradiol ratio (T/E2 ratio) were significantly decreased in CAD patients compared with controls. Patients with high GDF-15 levels had lower testosterone (203.97, 95% CI 154.67-328.30 vs. 303.98, 95% CI 246.93-345.66; P = 0.001) and T/E2 ratio (8.82, 95% CI 5.77-11.41 vs. 11.07, 95% CI 7.91-14.32; P = 0.013). Correlation analyses showed that serum GDF-15 levels inversely correlated with testosterone levels (r = -0.339) and T/E2 ratio (r = -0.365) (both P < 0.001). In multivariate regression analyses, the association between GDF-15 and T/E2 ratio was maintained (B=-0.442, 95% CI -99.568 to -6.991, P = 0.015). Furthermore, in vitro studies showed a synergistic effect of testosterone and estradiol on GDF-15 secretion, and demonstrated that testosterone association with estradiol decreased GDF-15 secretion through androgen receptor/estrogen receptor-mediated pathways. Together, these results suggest that upregulation of GDF-15 in the presence of low and imbalanced sex hormone levels may contribute to CAD. Thus, restoring the balance of testosterone and estradiol may inhibit the effects of GDF-15 and serve as a promising therapeutic strategy for the treatment of CAD.

The association between serum testosterone and insulin resistance: a longitudinal study

The objective of this study was to investigate whether there is a bidirectional association between testosterone concentrations and insulin resistance, in a prospective population study. A random population sample of 1400 men, aged 30-74, was examined in 2002-2005 in southwestern Sweden and followed up in 2012-2014 (N = 657). After excluding subjects without information on sex hormones and insulin resistance, 1282 men were included in the baseline study. Fasting measurements of plasma glucose, insulin and hormones were performed. Insulin resistance was defined using HOMA-Ir. Mean age at baseline was 47.3 ± 11.4 years. From the follow-up survey 546 men were included, mean age 57.7 ± 11.6 years. Low concentrations of total testosterone at baseline were significantly associated with high logHOMA-Ir at follow-up in a multivariable model including age, waist-hip ratio, physical activity, alcohol intake, smoking, LDL, CRP, hypertension, diabetes and logHOMA-Ir at baseline as covariates (β = -0.096, P = 0.006). Similar results were observed for bioavailable testosterone. Men within the lowest quartile of total testosterone at baseline had significantly higher logHOMA-Ir at follow-up than other quartiles (Q1 vs Q2 P = 0.008, Q1 vs Q3 P = 0.001, Q1 vs Q4 P = 0.052). Multivariable analysis of the impact of insulin resistance at baseline on testosterone levels at follow-up revealed no significant associations regarding testosterone concentrations (β = -0.003, P = 0.928) or bioavailable testosterone (β = -0.006, P = 0.873), when adjusting for baseline concentrations of total testosterone, age, waist-hip-ratio, LDL, CRP, physical activity, alcohol intake, smoking, hypertension and diabetes. Low testosterone concentrations at baseline predicted higher insulin resistance at follow-up, but high insulin resistance at baseline could not predict low testosterone at follow-up.

Low-protein diet in puberty impairs testosterone output and energy metabolism in male rats

We examined the long-term effects of protein restriction during puberty on the function of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes in male rats. Male Wistar rats from the age of 30 to 60 days were fed a low-protein diet (4%, LP). A normal-protein diet (20.5%) was reintroduced to rats from the age of 60 to 120 days. Control rats were fed a normal-protein diet throughout life (NP). Rats of 60 or 120 days old were killed. Food consumption, body weight, visceral fat deposits, lipid profile, glycemia, insulinemia, corticosteronemia, adrenocorticotropic hormone (ACTH), testosteronemia and leptinemia were evaluated. Glucose-insulin homeostasis, pancreatic-islet insulinotropic response, testosterone production and hypothalamic protein expression of the androgen receptor (AR), glucocorticoid receptor (GR) and leptin signaling pathway were also determined. LP rats were hypophagic, leaner, hypoglycemic, hypoinsulinemic and hypoleptinemic at the age of 60 days (P < 0.05). These rats exhibited hyperactivity of the HPA axis, hypoactivity of the HPG axis and a weak insulinotropic response (P < 0.01). LP rats at the age of 120 days were hyperphagic and exhibited higher visceral fat accumulation, hyperleptinemia and dyslipidemia; lower blood ACTH, testosterone and testosterone release; and reduced hypothalamic expression of AR, GR and SOCS3, with a higher pSTAT3/STAT3 ratio (P < 0.05). Glucose-insulin homeostasis was disrupted and associated with hyperglycemia, hyperinsulinemia and increased insulinotropic response of the pancreatic islets. The cholinergic and glucose pancreatic-islet responses were small in 60-day-old LP rats but increased in 120-day-old LP rats. The hyperactivity of the HPA axis and the suppression of the HPG axis caused by protein restriction at puberty contributed to energy and metabolic disorders as long-term consequences.

Testosterone a key factor in gender related metabolic syndrome

Metabolic syndrome (MetS) is highly correlated with cardiovascular diseases. Although an excess of body fat is a determinant factor for MetS development, a reduced level of testosterone plays a fundamental role in its regulation. Low testosterone level is highly related to insulin resistance, visceral obesity and MetS. We have searched in Pubmed clinical trial with the password: testosterone and insulin resistance, and testosterone and MetS. We found 19 studies on the correlation between testosterone level with insulin resistance and 18 on the effect of testosterone therapy on MetS. A high correlation between low testosterone and insulin resistance has been found in men, but not in women. Testosterone administration in hypogonadal men improved MetS and reduced the mortality risk. Androgen and oestrogen receptors are expressed in adipocytes, muscle and liver tissue, and their activation is necessary to improve metabolic control. Normalization of testosterone level should be the primary treatment in men, along with caloric restriction and physical exercise. These findings come mainly from correlative data, and there remains a need for randomized trials to strengthen this evidence. This review will consider the effects of testosterone on the regulation and development of MetS in men and women.

Gonadal Hormones and Retinal Disorders: A Review

AIM

Gonadal hormones are essential for reproductive function, but can act on neural and other organ systems, and are probably the cause of the large majority of known sex differences in function and disease. The aim of this review is to provide evidence for this hypothesis in relation to eye disorders and to retinopathies in particular.

METHODS

Epidemiological studies and research articles were reviewed.

RESULTS

Analysis of the biological basis for a relationship between eye diseases and hormones showed that estrogen, androgen, and progesterone receptors are present throughout the eye and that these steroids are locally produced in ocular tissues. Sex hormones can have a neuroprotective action on the retina and modulate ocular blood flow. There are differences between the male and the female retina; moreover, sex hormones can influence the development (or not) of certain disorders. For example, exposure to endogenous estrogens, depending on age at menarche and menopause and number of pregnancies, and exposure to exogenous estrogens, as in hormone replacement therapy and use of oral contraceptives, appear to protect against age-related macular degeneration (both drusenoid and neurovascular types), whereas exogenous testosterone therapy is a risk factor for central serous chorioretinopathy. Macular hole is more common among women than men, particularly in postmenopausal women probably owing to the sudden drop in estrogen production in later middle age. Progestin therapy appears to ameliorate the course of retinitis pigmentosa. Diabetic retinopathy, a complication of diabetes, may be more common among men than women.

CONCLUSION

We observed a correlation between many retinopathies and sex, probably as a result of the protective effect some gonadal hormones may exert against the development of certain disorders. This may have ramifications for the use of hormone therapy in the treatment of eye disease and of retinal disorders in particular.

The protective role of oestradiol against silent myocardial ischemia and hypertension risk in South African men: The SABPA study

BACKGROUND

Oestradiol has a protective effect on coronary artery health in women but the effect it has on men, is controversial. A translational approach was followed to assess whether sex hormone levels are associated with silent myocardial ischemia (SMI) and hypertension risk over a 3year period.

METHODS

Participants included 89 Black and 91 White men (aged 21-63years) participating in both phases of the Sympathetic activity and Ambulatory Blood Pressure in Africans prospective study. Fasting blood samples, ambulatory blood pressure and 2-lead ECG recordings were obtained.

RESULTS

No difference in the levels of the various baseline serum T fractions between the two ethnic groups occurred. Oestradiol of the Black men increased by 54.2% compared to a decrease of 24.1% in the White men. Changes in total oestradiol (adjusted R²=0.33, β=-0.31, p=0.023) and free oestradiol (adjusted R²=0.34, β=-0.33, p=0.019) were inversely associated with changes in SMI in the Black men but not in White men. Baseline serum nitric oxide metabolites were inversely associated with ΔSMI in the Blacks only (adjusted R²=0.33, β=-0.28, p=0.047). Chronic SMI was associated with 24h hypertension in Blacks [cut point 1.5 events: Area under the curve 0.71 (95% CI: 0.60, 0.82); p=0.006; with sensitivity/specificity 44%/94%].

CONCLUSIONS

Chronic SMI events facilitated future ischemic heart disease in Black men. Up-regulated free oestradiol seems to be involved in the protection of the heart against SMI and hypertension risk in Black but not in White men. A similar protective role for testosterone could however not be shown.

Effects of testosterone supplementation therapy on lipid metabolism in hypogonadal men with T2DM: a meta-analysis of randomized controlled trials

Testosterone supplementation may be effective for the treatment of hypogonadism in men with type 2 diabetes mellitus (T2DM), but the evidence from randomized controlled trials (RCTs) is inconclusive. We aimed to systematically summarize results from intervention studies and assess the effects of testosterone supplementation therapy (TST) on lipid metabolism in RCTs of hypogonadal men with T2DM by meta-analysis. PubMed, Embase, and Cochrane Library databases were searched for studies reporting the effect of TST on lipid metabolism in hypogonadal men with T2DM until December 31, 2016. Seven RCTs from 252 trials, enrolling a total of 612 patients in the experimental and control groups with a mean age of 58.5 years, were included in this study. The pooled results of the meta-analysis demonstrated that TST significantly decreased TC and TG levels in hypogonadal men with T2DM compared with the control group, with mean differences (MDs) of -6.44 (95% CI: -11.82 to -1.06; I²  = 28%; p = 0.02) and -27.94 (95% CI: -52.33 to -3.54; I²  = 76%; p = 0.02). Subgroup analyses revealed that the heterogeneity (I²  = 76%) of TG originated from different economic regions, in which economic development, genetic and environmental factors, and dietary habits affect lipid metabolism of human, with a decrease (I²  = 45%) in developed countries. Additionally, subgroup analyses showed that TST increased HDL-C level in developing countries compared with the control group (MD = 2.79; 95% CI: 0.73 to 4.86; I²  = 0%; p = 0.008), but there was no improvement in developed countries (MD = 1.02; 95% CI: -4.55 to 6.60; I²  = 91%; p = 0.72). However, LDL-C levels were not improved consistently. Because the relationship between lipid metabolism and atherosclerosis is unequivocal, TST, which ameliorates lipid metabolism, may decrease the morbidity and mortality of cardiovascular disease in hypogonadal men with T2DM by preventing atherogenesis.

Prostanoids in the pathophysiology of human coronary artery

Coronary artery disease is one of the leading causes of death in wordwide. There is growing evidence that prostanoids are involved in the physiology and pathophysiology of the human coronary artery by controlling vascular tone, remodelling of the vascular wall or angiogenesis. In this review, the production of prostanoids and the expression of prostanoid receptors in human coronary artery in health or disease are described. In addition, the interactions between sex hormones and prostanoids, their participations in the development of coronary artery diseases have been addressed. Globally, most of the studies performed in human coronary artery preparations have shown that prostacyclin (PGI₂) has beneficial effects by inducing vasodilatation and promoting angiogenesis while reverse effects are confirmed by thromboxane A₂ (TxA₂). More studies are needed to determine the roles of the other prostanoids (PGE₂, PGD₂ and PGF_2α) in vascular functions of the human coronary artery. Finally, in addition to the in vitro data about the human coronary artery, myocardial infarction induced by cyclooxygenase-2 (COX-2) inhibitor and the protective effects of aspirin after coronary artery bypass surgery suggest that prostanoids are key mediators in coronary homeostasis.

Long-Term Testosterone Therapy Improves Cardiometabolic Function and Reduces Risk of Cardiovascular Disease in Men with Hypogonadism: A Real-Life Observational Registry Study Setting Comparing Treated and Untreated (Control) Groups

Objectives:

In the absence of large, prospective, placebo-controlled studies of longer duration, substantial evidence regarding the safety and risk of testosterone (T) therapy (TTh) with regard to cardiovascular (CV) outcomes can only be gleaned from observational studies. To date, there are limited studies comparing the effects of long-term TTh in men with hypogonadism who were treated or remained untreated with T, for obvious reasons. We have established a registry to assess the long-term effectiveness and safety of T in men in a urological setting. Here, we sought to compare the effects of T on a host of parameters considered to contribute to CV risk in treated and untreated men with hypogonadism (control group).

Patients and Methods:

Observational, prospective, cumulative registry study in 656 men (age: 60.7 ± 7.2 years) with total T levels ≤12.1 nmol/L and symptoms of hypogonadism. In the treatment group, men (n = 360) received parenteral T undecanoate (TU) 1000 mg/12 weeks following an initial 6-week interval for up to 10 years. Men (n = 296) who had opted against TTh served as controls. Median follow-up in both groups was 7 years. Measurements were taken at least twice a year, and 8-year data were analyzed. Mean changes over time between the 2 groups were compared by means of a mixed-effects model for repeated measures, with a random effect for intercept and fixed effects for time, group, and their interaction. To account for baseline differences between the 2 groups, changes were adjusted for age, weight, waist circumference, fasting glucose, blood pressure, and lipids.

Results:

There were 2 deaths in the T-treated group, none was related to CV events. There were 21 deaths in the untreated (control) group, 19 of which were related to CV events. The incidence of death in 10 patient-years was 0.1145 in the control group (95% confidence interval [CI]: 0.0746-0.1756; P < .000) and 0.0092 in the T-treated group (95% CI: 0.0023-0.0368; P < .000); the estimated difference between groups was 0.0804 (95% CI: 0.0189-0.3431; P < .001). The estimated reduction in mortality for the T-group was between 66% and 92%. There were also 30 nonfatal strokes and 26 nonfatal myocardial infarctions in the control group and none in the T-treated group.

Conclusion:

Long-term TU was well tolerated with excellent adherence suggesting a high level of patient satisfaction. Mortality related to CV disease was significantly reduced in the T-group.

Prevalence of hypogonadism in male Type 2 diabetes mellitus patients with and without coronary artery disease

AIM

The present study is carried out to investigate hypogonadism using serum testosterone levels in male Type 2 diabetes mellitus (T2DM) subjects with and without coronary artery disease (CAD).

SUBJECTS AND METHODS

A total of 150 age and body mass index-matched male subjects in the age group of 30-70 years were recruited in three groups; Group A - subjects with normal glucose tolerance, Group B - T2DM subjects without CAD, and Group C - T2DM subjects with CAD (n = 50 each group). Subjects with CAD were diagnosed on the basis of electrocardiogram, treadmill testing, stress echocardiography, or coronary angiography. Total testosterone (TT), free testosterone (FT), bioavailable testosterone, calculated FT and glycemic parameters were measured and compared between all the three study groups. One-way ANOVA followed by post hoc Tukey's test and Pearson's coefficient of correlation tests were used for analysis.

RESULTS

Hypogonadism (TT <3 ng/ml) was observed in 40% (20/50) of subjects in Group C and 32% (16/50) of subjects in Group B as compared to only 14% (7/50) of subjects in Group A (Groups A vs. B; P = 0.055, Groups A vs. C; P = 0.006 and Groups B vs. C; P = 0.53). Group C subjects had significantly lower levels of TT (3.55 ± 1.46 ng/ml vs. 4.73 ± 2.17 ng/ml, P = 0.005), calculated FT (0.062 ± 0.0255 pg/ml vs. 0.0951 ± 0.0508 pg/ml, P ≤ 0.001), and bioavailable testosterone (1.48 ± 0.65 ng/ml vs. 2.18 ± 1.20 ng/ml, P ≤ 0.001) compared to control Group A subjects. There was no significant difference in any of the testosterone parameters between Groups A and B. Furthermore, an overall positive correlation was found between hypogonadism and CAD (r = 0.177, P = 0.030, n = 150).

CONCLUSION

We observed hypogonadism as indicated by low testosterone levels in a significant proportion of male T2DM subjects with CAD.

Testosterone therapy and prostate cancer

The use of exogenous testosterone to treat hypogonadism in the men with a history of prostate cancer (CaP) remains controversial due to fears of cancer recurrence or progression. Due to the detrimental impact of hypogonadism on patient quality of life, recent work has examined the safety of testosterone therapy (TTh) in men with a history of CaP. In this review, we evaluate the literature with regards to the safety of TTh in men with a history of CaP. TTh results in improvements in quality of life with little evidence of biochemical recurrence or progression in men with a history of CaP, or de novo cancer in unaffected men. An insufficient amount of evidence is currently available to truly demonstrate the safe use of TTh in men with low risk CaP. In men with high-risk cancer, more limited data suggest that TTh may be safe, but these findings remain inconclusive. Despite the historic avoidance of TTh in men with a history of CaP, the existing body of evidence largely supports the safe and effective use of testosterone in these men, although additional study is needed before unequivocal safety can be demonstrated.