Long-term benefits of testosterone replacement therapy on angina threshold and atheroma in men

Evaluating the impact of testosterone replacement therapy on carotid atherosclerosis: a systematic review and meta-analysis

Aim: This meta-analysis investigates the association between testosterone replacement therapy [TRT] and carotid artery atherosclerosis. Methods: 3 databases were searched for studies up to June 2023 per the PRISMA guidelines. The eligibility criteria comprised RCTs and observational studies involving hypogonadal males receiving exogenous testosterone, in which CIMT was assessed. CAA was the primary outcome, whereas secondary outcomes included HDL, LDL, CRP, total cholesterol and total testosterone. The statistical analysis was performed using Review Manager. Results: Statistical analysis revealed no association between TRT and assessed outcomes. There was a significant increase in total testosterone levels, depicting indirect anti-atherosclerotic effects of TRT. Conclusion: Meta-analysis shows no relation between TRT and CIMT or other markers, allowing its safe usage for hypogonadal males.

Novel perspectives of testosterone therapy in men with functional hypogonadism: traversing the gaps of knowledge

INTRODUCTION

In the past decade, there has been a significant augmentation in the corpus of evidence pertaining to functional hypogonadism. Despite this, prevailing clinical guidelines continue to advise against the universal screening for hypogonadism in middle-aged and elderly males.

FINDINGS

Numerous randomized controlled trials have scrutinized the effects of testosterone therapy in males afflicted with type 2 diabetes and/or obesity. However, these guidelines uniformly assert that lifestyle modifications and weight reduction should be the primary intervention strategies in overweight and obese males, relegating testosterone therapy to a secondary, selective option. It is extensively documented that testosterone therapy can yield substantial improvements in various metabolic parameters as well as ameliorate symptoms of erectile dysfunction. Moreover, recent studies have demonstrated the potential of testosterone therapy in reversing type 2 diabetes in males with low-normal testosterone levels who are at elevated risk for this condition, in comparison to the outcomes achievable through lifestyle modifications alone.

CONCLUSION

This focused review article aims to present a comprehensive update on the latest data concerning the innovative aspects of testosterone therapy in males with functional hypogonadism, particularly in the context of type 2 diabetes and/or obesity. Additionally, it will delve into the cardiovascular safety of such interventions within this high-risk demographic, with a special emphasis on insights gleaned from the TRAVERSE trial.

Androgen Society Position Paper on Cardiovascular Risk With Testosterone Therapy

The Androgen Society is an international, multidisciplinary medical organization committed to advancing research and education in the field of testosterone deficiency and testosterone therapy (TTh). This position paper is written in response to results of the TRAVERSE study, published in June 2023, which reported no increased risk of major adverse cardiovascular events (MACE) in men who received TTh compared with placebo. In 2013-2014, 2 observational studies reported increased cardiovascular (CV) risks with TTh and received wide media attention. Despite strong criticism of those 2 studies, in 2015, the Food and Drug Administration added a CV warning to testosterone product labels and required pharmaceutical companies to perform a CV safety study, which became the TRAVERSE trial. TRAVERSE enrolled 5246 men at high risk for MACE based on existing heart disease or multiple risk factors. Participants were randomized to daily testosterone gel or placebo gel, with a mean follow-up of 33 months. Results revealed no greater risk of MACE (myocardial infarction, stroke, or CV death) or venothrombotic events in men who received TTh compared with placebo. Review of the prior literature reveals near uniformity of studies reporting no increased MACE with TTh. This includes 2 additional large randomized controlled trials, multiple smaller randomized controlled trials, several large observational studies, and 19 meta-analyses. In view of these findings, it is the position of the Androgen Society that it has now been conclusively determined that TTh is not associated with increased risks of heart attack, stroke, or CV death.

Cardiovascular disease and testosterone therapy in male hypogonadism

This review assesses the evidence of the physiological effects of testosterone on cardiovascular health, the association between male hypogonadism and cardiovascular health, and the effects of testosterone therapy on cardiovascular health in male hypogonadism. Preclinical studies suggest complex effects of testosterone on cardiovascular risk by acting on skeletal muscle, cardiomyocytes, vasculature, adipocytes, insulin action, and erythropoiesis. Furthermore, low testosterone has a bi-directional association with cardiometabolic risk. Observational studies have reported worse metabolic profiles in men with organic hypogonadism. However, a consistent association between major cardiovascular events and male hypogonadism has not been established. Hematocrit increases with testosterone therapy; however, most studies do not report an increase in venous thromboembolism risk. Although some observational studies and a small randomized controlled study reported an increased risk of cardiovascular disease, recent data confirm the medium-term cardiovascular safety of testosterone therapy in middle-aged and older men with low testosterone.

Cardiovascular safety of testosterone replacement therapy in men: an updated systematic review and meta-analysis

INTRODUCTION

The cardiovascular (CV) safety of testosterone (T) replacement therapy (TRT) is still conflicting. Recent data suggested a TRT-related increased risk of atrial fibrillation (AF). The aim of this study was to systematic review and meta-analyze CV risk related to TRT as derived from placebo controlled randomized trials (RCTs).

AREAS COVERED

An extensive Medline, Embase, and Cochrane search was performed. All placebo-controlled RCTs reporting data on TRT-related CV safety were considered. To better analyze the role of T on AF, population-based studies investigating the relationship between endogenous circulating T levels and AF incidence were also included and analyzed.

EXPERT OPINION

Out of 3.615, 106 studies were considered, including 8.126 subjects treated with TRT and 7.310 patients allocated to placebo. No difference between TRT and placebo was observed when major adverse CV events were considered. Whereas the incidence of non-fatal arrhythmias and AF was increased in the only trial considering CV safety as the primary endpoint, this was not confirmed when all other studies were considered (MH-OR 1.61[0.84;3.08] and 1.44[0.46;4.46]). Similarly, no relationship between endogenous T levels and AF incidence was observed after the adjustment for confounders Available data confirm that TRT is safe and it is not related to an increased CV risk.

Testosterone therapy and the risk of cardiovascular disease in older, hypogonadal men

The debate over the cardiovascular (CV) implications of testosterone therapy (TT) have resulted in diverging safety recommendations and clinical guidelines worldwide. This narrative review synthesizes and critically evaluates long-term studies examining the effects of TT within the context of aging, obesity, and endogenous sex hormones on CV disease (CVD) risk to support informed clinical decision-making. Observational studies have variably linked low endogenous testosterone with increased CVD risk, while randomized controlled trials (RCTs) demonstrate that TT yields cardiometabolic benefits without increasing short-term CV risk. The TRAVERSE trial, as the first RCT powered to assess CVD events, did not show increased major adverse cardiac events (MACE) incidence; however, its limitations - specifically the maintenance of testosterone at low-normal levels, a high participant discontinuation rate, and short follow-up - warrant a careful interpretation of its results. Furthermore, findings from the TTrials cardiovascular sub-study, which showed an increase in non-calcified plaque, indicate the need for ongoing research into the long-term CV impact of TT. The decision to initiate TT should consider the current evidence gaps, particularly for older men with known CVD. The CV effects of maintaining physiological testosterone levels through exogenous means remain to be fully explored. Until more definitive evidence is available, clinical practice should prioritize individualized care and informed discussions on the potential CV implications of TT.

A review of testosterone supplementation and cardiovascular risk

Testosterone therapy is commonly utilized to treat hypogonadism. After diagnosis with morning serum testosterone level in patients with symptoms of hypogonadism, therapy has been shown to improve symptoms. Research focusing on cardiovascular risks associated with testosterone therapy has produced contradictory statements. We review trials that have investigated the impact of testosterone supplementation on heart failure, coronary artery disease, and myocardial ischemia.

The effects of long-term testosterone treatment on endocrine parameters in hypogonadal men: 12-year data from a prospective controlled registry study

Testosterone therapy (TTh) is the primary treatment for aging men with functional hypogonadism. Whilst the benefits of testosterone (T) replacement are well-evidenced, the long-term data for TTh on metabolic and endocrine parameters is limited. Here we present the effect of TTh on endocrine parameters in hypogonadal men at a 12-year follow-up. In this single-centre, cumulative, prospective, registry study, 321 hypogonadal men (mean age: 58.9 years) received testosterone undecanoate injections in 12-week intervals for up to 12 years. Blood samples were taken at every other visit to measure levels of total T (TT), calculated free T, sex hormone-binding globulin (SHBG), estradiol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone and prolactin. We observed an increase in TT of 15.5 nmol/L (p < 0.0001), a reduction in SHBG of 10.5 nmol/L (p < 0.0001) and an increase in calculated free T of 383.04 pmol/L (p < 0.0001) over the study period. This was accompanied by an increase in estradiol levels by 14.9 pmol/L (p < 0.0001), and decreases in progesterone (0.2 ng/mL, p < 0.0001), LH (10.4 U/L, p < 0.0001) and FSH (8.4 U/L, p < 0.0001) were demonstrated at 12-years. The levels of prolactin remained unchanged. Long-term TTh altered hormonal parameters to predictably modify the endocrine system. These effects were sustained during the entire observation time of 12 years.

[Testosterone treatment]

Male hypogonadism is a congenital or acquired disorder that exerts a negative influence on various organ functions and can massively impair the quality of life through the relative or absolute deficiency of testosterone. A variety of preparations are available for substitution treatment, which differ in administration form and intake interval. For the execution of testosterone treatment various guidelines exist with clear and practical instructions on the indications, contraindications, treatment procedure and monitoring. Of particular importance are cardiovascular aspects and diseases of the prostate gland, which underlines the central position of the urologist in the treatment.

Testosterone replacement therapy and cardiovascular disease

The use of testosterone therapy has a complex history of apprehension and questions regarding its safety. Despite an eventual consensus that testosterone therapy was safe and effective, several studies relating to cardiovascular risks emerged in the last decade, rekindling skepticism regarding the safety of testosterone therapy. Given the utility of testosterone therapy in treating the symptoms of hypogonadism, it remains crucial to closely examine the safety of testosterone therapy. The present article synthesizes the current evidence regarding cardiovascular risks that may be associated with testosterone therapy, the potential mechanisms regarding testosterone's efficacy, and future directions in evaluating the safety of its use.

The Roles of Androgens in Humans: Biology, Metabolic Regulation and Health

Androgens are an important and diverse group of steroid hormone molecular species. They play varied functional roles, such as the control of metabolic energy fate and partition, the maintenance of skeletal and body protein and integrity and the development of brain capabilities and behavioral setup (including those factors defining maleness). In addition, androgens are the precursors of estrogens, with which they share an extensive control of the reproductive mechanisms (in both sexes). In this review, the types of androgens, their functions and signaling are tabulated and described, including some less-known functions. The close interrelationship between corticosteroids and androgens is also analyzed, centered in the adrenal cortex, together with the main feedback control systems of the hypothalamic-hypophysis-gonads axis, and its modulation by the metabolic environment, sex, age and health. Testosterone (T) is singled out because of its high synthesis rate and turnover, but also because age-related hypogonadism is a key signal for the biologically planned early obsolescence of men, and the delayed onset of a faster rate of functional losses in women after menopause. The close collaboration of T with estradiol (E2) active in the maintenance of body metabolic systems is also presented Their parallel insufficiency has been directly related to the ravages of senescence and the metabolic syndrome constellation of disorders. The clinical use of T to correct hypoandrogenism helps maintain the functionality of core metabolism, limiting excess fat deposition, sarcopenia and cognoscitive frailty (part of these effects are due to the E2 generated from T). The effectiveness of using lipophilic T esters for T replacement treatments is analyzed in depth, and the main problems derived from their application are discussed.

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.

The Effect of Testosterone on Cardiovascular Disease and Cardiovascular Risk Factors in Men: A Review of Clinical and Preclinical Data

Cardiovascular disease (CVD) is the leading cause of death worldwide. The effects of testosterone, the primary male sex hormone, on cardiovascular risk have been of special interest due to the increased risk of CVD in men. Although it is well established that testosterone levels decline and cardiovascular mortality increases with age, the association between testosterone and CVD remains unclear. Observational and randomized studies on the effects of endogenous and exogenous testosterone have produced conflicting data, and meta-analyses have been inconclusive, suggesting significant study heterogeneity. Despite a lack of adequately powered randomized controlled trials, large observational studies in the early 2010s led to advisories on the use of testosterone replacement therapy. Similar advisories have been mandated for certain types of androgen deprivation therapy. Additional research suggests that testosterone shortens the heart-rate-corrected QT interval, improves glycemic control, induces vasodilation, is prothrombotic, and has anti-obesity effects, whereas associations with atherosclerosis and inflammation are less clear. Despite inconclusive evidence on cardiovascular risk and inconsistencies among clinical practice guidelines, millions of men continue to use testosterone replacement and androgen deprivation therapy. In addition to summarizing clinical and preclinical data, this review provides insight on potential mechanisms of action of testosterone on CVD, applications of this knowledge to clinical settings, and avenues for future research.

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.

Testosterone Replacement Therapy in Hypogonadal Men and Myocardial Infarction Risk: Systematic Review & Meta-Analysis

Testosterone replacement therapy (TRT) has become increasingly popular over the years and there has been an increasing debate on whether testosterone replacement should be offered to older men due to its association with cardiovascular events. In this study, we evaluated the risk of myocardial infarction (MI) associated with TRT in hypogonadal men through a meta-analysis. We carried out the analysis by following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines and conducted a literature search utilizing the following databases: Google Scholar, PubMed, Science Direct, Cochrane Library trials, and ClinicalTrials.gov. The search strategy resulted in a total of 782 articles, after applying our inclusion and exclusion criteria. Six observational studies and two randomized controlled trials (RCTs) were included for the analysis. A total of 55,806 hypogonadal men with baseline testosterone levels <300ng/mL were included in the analysis. The intervention group received testosterone in various routes including transdermal patches, gels, mouth patches, testosterone injections, and deposits. The incidence of MI was taken to be the primary measure outcomes. The pooled data from eight studies showed MI incidence in 249 out of 11,720 (2.1%) in the TRT group and 1420 out of 33,086 (4.3%) in the control group. The pooled OD showed no statistically significant association of TRT and MI compared to the control group (OR = 0.76, 95% CI 0.36-1.31; p=0.48). The model revealed high heterogeneity with I2 =79%. With sensitivity analysis and, excluding two studies out of the eight, the pooled data was able to achieve low heterogeneity with I2 = 0%. The newly pooled data from six studies showed MI incidence in 226 out of 10,137 (2.2%) in the TRT group and 969 out of 36,304 (2.7%) in the control group. The pooled OD shows no statistical significance in the association between TRT treatment and MI compared to the control group. (OR =0.87, 95% CI 0.75-1.01; P =0.08). It appears that TRT does not increase the risk of MI as compared to the non-intervention group. Further RCTs with greater population size are needed that could produce more solid results, allowing more definitive conclusions to be made on this topic.

Testosterone therapy and cardiovascular diseases

Since it was first synthesised in 1935, testosterone (T) has been viewed as the mythical Fountain of Youth, promising rejuvenation, restoring sexual appetites, growing stronger muscles, and quicker thinking. T is endowed with direct effects on myocardial and vascular structure and function, as well as on risk factors for cardiovascular (CV) disease. Indeed, low serum T levels are a risk factor for diabetes, metabolic syndrome, inflammation, and dyslipidaemia. Moreover, many studies have shown that T deficiency per se is an independent risk factor of CV and all-cause mortality. On this background and due to direct-to-patient marketing by drug companies, we have witnessed to the widespread use of T replacement therapy (TT) without clear indications particularly in late-life onset hypogonadism. The current review will dwell upon current evidence and controversies surrounding the role of T in the pathophysiology of CV diseases, the link between circulating T levels and CV risk, and the use of replacing T as a possible adjuvant treatment in specific CV disorders. Specifically, recent findings suggest that heart failure and type 2 diabetes mellitus represent two potential targets of T therapy once that a state of hypogonadism is diagnosed. However, only if ongoing studies solve the CV safety issue the T orchid may eventually 'bloom'.

Testosterone replacement therapy in hypogonadal male patients with hypogonadism and heart failure: a meta-analysis of randomized controlled studies

BACKGROUND

The recently published guidelines of the European Academy of Andrology (EAA) recommended not to prescribe testosterone replacement therapy (TRT) in male patients with hypotestosteronemia and severe heart failure (HF) [New York Hearth Association (NYHA) class III and IV] since the risk in these patients has not been formally documented. Therefore, the aim of this study was to systematically evaluate the risk of TRT on the cardiac function and angina, in male patients with hypotestosteronemia and HF or coronary heart disease.

METHODS

Randomized controlled trials (RCTs) on male patients with hypotestosteronemia and chronic HF (ejection fraction <40%) or stable angina documenting the effect of TRT on NYHA class, left ventricula ejection fraction (LVEF), adverse events, ST depression and other indexes of cardiovascular function.

RESULTS

Seven articles were included, for a total of 140 participants with HF (71 on TRT and 69 on placebo or no treatment). Included patients were of NYHA class II and III. TRT had no effect on death and rehospitalization rates of patients with HF and significantly delayed the time to ischemia in patients with chronic angina. TRT had not effect on the NYHA class, the LVEF, and on the Minnesota Living with Heart Failure questionnaire. Although a significant increase of oxygen consumption was found in the TRT group, no improvement to the physical exercise tolerance tests was observed. TRT showed no effect on systolic nor diastolic blood pressure, but it significantly ameliorated the heart rate. It significantly decreased the insulin serum levels and the HOMA index.

CONCLUSIONS

These results suggest the safety of TRT, in patients with hypotestosteronemia and severe HF (class NYHA II and III). Although deriving from a limited number of studies, these data could prompt to perform other RCTs on the effects of TRT in patients with hypotestosteronemia and severe HFrEF (NYHA class III).

Effect of Co-administration of Agnus castus Aqueous Leaf Extract and Cadmium Chloride on Testicular Function Indices

Background: Cadmium toxicity is an environmental health menace in developing countries, which can result in damage to the male reproductive system. The mechanisms of cadmium toxicity include an increase in lipid peroxidation, depletion of glutathione, reduction in protein-bound sulfhydryl groups, and increase of oxidative stress. Agnus castus has been differently reported for its strong antioxidant potential and reproductive-enhancing properties. These two properties make the plant viable for the possible amelioration of cadmium toxicity. Objectives: This study was carried out to investigate the effect of Agnus castus aqueous leaf extract on the testicular function indices in cadmium chloride-treated rats. Methods: Twenty-five male Wistar rats (100 - 160) g, Rattus norvegicus strain, were randomly distributed into five different groups, each containing five animals. The animals were grouped as follows. Group A (control group) received distilled water, and group B received 6.5 mg/kg body weight of cadmium chloride. Groups C, D, and E received 6.5 mg/kg body weight of cadmium chloride each together with 50 mg/kg, 100 mg/kg, and 200 mg/kg body weight of aqueous extract of Agnus castus, respectively. The administration was done by oral gavage, once daily for 21 days. The animals were finally sacrificed on day 22. The serum was collected, and the testis was excised for testicular function indices, hormonal assays, and antioxidant activities. Results: Exposure to cadmium chloride caused a significant reduction (P < 0.05) in the weight of the testes and antioxidant enzymes (catalase, superoxide dismutase, and reduced glutathione) compared to the control group. However, co-treatment with cadmium chloride and Agnus castus leaves resulted in the amelioration of cadmium-induced reduction in testicular weight and antioxidant enzymes. Exposure to cadmium chloride caused a significant decrease in testosterone, follicle-stimulating hormone, and luteinizing hormone when compared to the control group. Co-treatment with cadmium chloride and Agnus castus increased the levels of glycogen, testosterone, follicle-stimulating hormone, and luteinizing hormone in the rats’ testes. Conclusions: The aqueous leaf extract of Agnus castus displayed a protective role in testicular function and antioxidants in Wistar rats against cadmium chloride toxicity, compared to control rats that received distilled water only.

Testosterone stimulates cholesterol clearance from human macrophages by activating LXRα

AIMS

Low testosterone in men is associated with increased cardiovascular events and mortality. Testosterone has beneficial effects on several cardiovascular risk factors including cholesterol, endothelial dysfunction and inflammation as key mediators of atherosclerosis. Although evidence suggests testosterone is anti-atherogenic, its mechanism of action is unknown. The present study investigates whether testosterone exerts anti-atherogenic effects by stimulating cholesterol clearance from macrophages via activation of liver X receptor (LXRα), a nuclear master regulator of cellular cholesterol homeostasis, lipid regulation, and inflammation.

MAIN METHODS

Using human monocyte THP-1 cells differentiated into macrophages, the effect of testosterone (1-10 nM) treatment (24-72 h) on the expression of LXRα and LXR- targets apolipoprotein E (APOE), ATP-binding cassette transporter A1 (ABCA1), sterol regulatory element-binding transcription factor 1 (SREBF1) and fatty acid synthase (FAS), was investigated via qPCR and western blotting, with or without androgen receptor blockade with flutamide or LXR antagonism with CPPSS-50. Cholesterol clearance was measured by monitoring fluorescent dehydroergosterol (DHE) cellular clearance and ABCA1 cellular translocation was observed via immunocytochemistry in testosterone treated macrophages.

KEY FINDINGS

Testosterone increased mRNA and protein expression of LXRα, APOE, ABCA1, SREBF1 and FAS. These effects were blocked by flutamide and independently by LXR antagonism with CPPSS-50. Furthermore testosterone stimulated cholesterol clearance from the macrophages and promoted the translocation of ABCA1 toward the cell membrane.

SIGNIFICANCE

Testosterone acts via androgen receptor-dependent pathways to stimulate LXRα and downstream targets to induce cholesterol clearance in human macrophages. This may, in part, explain the anti-atherogenic effects of testosterone frequently seen clinically.

Effect of Testosterone Treatment on Cardiovascular Events in Men: Protocol for a Systematic Literature Review and Meta-Analysis

Background

Testosterone prescriptions have increased dramatically in recent decades, with increasing usage in men. Despite epidemiological associations reported high circulating concentrations of endogenous androgens and low risk of cardiovascular events and mortality, the effects of exogenous androgens in the form of testosterone therapy for maintaining physiological circulating androgen concentrations on the cardiovascular system remain uncertain with no published meta-analysis on this topic.

Objective

The aim of this study was to investigate the effects of prescribed testosterone treatment, in all forms and durations, from well-developed randomized controlled trials, on cardiovascular events in men aged 18 years or older.

Methods

Peer-reviewed journal articles published from 1980 to 2019 will be searched from databases (ie CINAHL [Cumulated Index to Nursing and Allied Health Literature], Embase, Medline, Scopus, Cochrane Controlled Register of Trials as well as the Clinical Trial Registry). Randomized controlled trials or cluster randomized controlled trials with at least one intervention arm of testosterone and a control group of usual care or no testosterone treatment will be included in this review and meta-analysis. Studies on men with previous cardiovascular events or cardiac vascularization (coronary bypass surgery or percutaneous coronary intervention) will be excluded. Data related to primary outcomes such as clinical events of any type of stroke or transient ischemic attack, nonfatal myocardial infarction or acute coronary syndrome, emergency coronary artery revascularization, carotid surgery, cardiac mortality, and all-cause mortality will be extracted for analysis. The criteria for PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) will be followed in the evaluation of evidence.

Results

Search terms have been piloted and finalized. This study will be completed by the end of 2020.

Conclusions

This protocol will guide a systematic literature review of the evidence around prescribed testosterone and its effect on cardiovascular events in men aged 18 years or older. The findings will inform clinical management of hypogonadal men.

Trial Registration

PROSPERO International Prospective Register of Systematic Reviews CRD42019134278; https://tinyurl.com/y6t7ggge

International Registered Report Identifier (IRRID)

PRR1-10.2196/15163

Testosterone therapy in hypogonadal patients and the associated risks of cardiovascular events

Since the male secondary sex characters, libido and fertility are attributed to their major androgen hormone testosterone, the sub-optimum levels of testosterone in young adults may cause infertility and irregularities in their sexual behaviour. Such deficiency is often secondary to maladies involving testes, pituitary or hypothalamus that could be treated with an administration of exogenous testosterone. In the last few decades, the number of testosterone prescriptions has markedly increased to treat sub-optimal serum levels even though its administration in such conditions is not yet approved. On account of its associated cardiovascular hazards, the food and drug authority in the United States has issued safety alerts on testosterone replacement therapy (TRT). Owing to a great degree of conflict among their findings, the published clinical trials seem struggling in presenting a decisive opinion on the matter. Hence, the clinicians remain uncertain about the possible cardiovascular adversities while prescribing TRT in hypogonadal men. The uncertainty escalates even further while prescribing such therapy in older men with a previous history of cardiovascular ailments. In the current review, we analysed the pre-clinical and clinical studies to evaluate the physiological impact of testosterone on cardiovascular and related parameters. We have enlisted studies on the association of cardiovascular health and endogenous testosterone levels with a comprehensive analysis of epidemiological studies, clinical trials, and meta-analyses on the cardiovascular risk of TRT. The review is aimed to assist clinicians in making smart decisions regarding TRT in their patients.

Hypogonadism management and cardiovascular health

In the early days of its use, testosterone therapy faced skepticism regarding its safety and efficacy. After a converging consensus that testosterone therapy was safe and effective for the treatment of hypogonadism, several recent studies showed adverse cardiovascular outcomes associated with testosterone treatment, ultimately resulting in a mandated FDA label warning about the unknown safety of testosterone therapy. Given the clear efficacy of testosterone therapy in the treatment of hypogonadism, establishing the safety of this therapeutic tool is essential. This article summarizes the current evidence regarding the cardiovascular safety of testosterone therapy for the management of hypogonadism, as well as the proposed mechanisms that may explain testosterone's underlying effects.

Late-onset hypogonadism: Reductio ad absurdum of the cardiovascular risk-benefit of testosterone replacement therapy

BACKGROUND

Low testosterone (T) level is considered a marker of poor cardiovascular health. Ten years ago, the Testosterone in Older Men with Mobility Limitations (TOM) trial was discontinued due to a higher number of adverse events in men receiving T compared with placebo. Since then, several studies have investigated the risks of T replacement therapy (TRT) in late-onset hypogonadism (LOH).

OBJECTIVE

To review the mechanism by which TRT could damage the cardiovascular system.

MATERIALS AND METHODS

Comprehensive literature search of recent clinical and experimental studies.

RESULTS

The mechanisms of T-mediated coronary vasodilation were reviewed with emphasis on calcium-activated and ATP-sensitive potassium ion channels. We showed how T regulates endothelial nitric oxide synthase (eNOS) and phosphoinositide 3-kinase/protein kinase B/eNOS signaling pathways in vessel walls and its direct effects on cardiomyocytes via β1-adrenergic and ryanodine receptors and provided data on myocardial infarction and heart failure. Vascular smooth muscle senescence could be explained by the modulation of growth factors, matrix metalloproteinase-2, and angiotensin II by T. Furthermore, leukocyte trafficking, facilitated by changes in TNF-α, could explain some of the effects of T on atheromatous plaques. Conflicting data on prothrombotic risk linked to platelet aggregation inhibition via NO-triggered arachidonate synthesis or increased aggregability due to enhanced thromboxane A in human platelets provide evidence regarding the hypotheses on plaque maturation and rupture risk. The effects of T on cardiac electrophysiology and oxygen delivery were also reviewed.

DISCUSSION

The effects of TRT on the cardiovascular system are complex. Although molecular studies suggest a potential benefit, several clinical observations reveal neutral or occasionally detrimental effects, mostly due to confounding factors.

CONCLUSIONS

Attempts to demonstrate that TRT damages the cardiovascular system via systematic analysis of the putative mechanisms led to the contradiction of the initial hypothesis. Current evidence indicates that TRT is safe once other comorbidities are addressed.

Effectiveness of testosterone therapy in hypogonadal patients and its controversial adverse impact on the cardiovascular system

Testosterone is the major male hormone produced by testicles which are directly associated with man's appearance and secondary sexual developments. Androgen deficiency starts when the male hormonal level falls from its normal range though, in youngsters, the deficiency occurs due to disruption of the normal functioning of pituitary, hypothalamus glands, and testes. Thus, testosterone replacement therapy was already known for the treatment of androgen deficiency with lesser risks of producing cardiovascular problems. Since from previous years, the treatment threshold in the form of testosterone replacement therapy has effectively increased to that extent that it was prescribed for those conditions which it was considered as inappropriate. However, there are some research studies and clinical trials available that proposed the higher risk of inducing cardiovascular disease with the use of testosterone replacement therapy. Thus under the light of these results, the FDA has published the report of the increased risk of cardiovascular disease with the increased use of testosterone replacement therapy. Nevertheless, there is not a single trial available or designed that could evaluate the risk of cardiovascular events with the use of testosterone replacement therapy. As a result, the use of testosterone still questioned the cardiovascular safety of this replacement therapy. Thus, this literature outlines the distribution pattern of disease by investigating the data and link between serum testosterone level and the cardiovascular disease, also the prescription data of testosterone replacement therapy patients and their tendency of inducing cardiovascular disease, meta-analysis and the trials regarding testosterone replacement therapy and its connection with the risks of causing cardiovascular disease and lastly, the possible effects of testosterone replacement therapy on the cardiovascular system. This study aims to evaluate the available evidence regarding the use of testosterone replacement therapy when choosing it as a treatment plan for their patients.

Hypogonadism and its treatment following ischaemic stroke in men with type 2 diabetes mellitus

Premature mortality in Russia is a major socio-economic problem, especially from acute cerebrovascular diseases which constitute 21.4% of the total mortality and is a considerable contributor to chronic disability. Risk of vascular catastrophe is higher in males than females, thought, in part, due to anti-atherosclerotic effects of oestrogens in females whilst an associated age-related deficiency of testosterone is observed in men. Clinical symptoms such as high blood pressure, changes in lipid profile, insulin resistance, obesity, and blood coagulation factors often accompany declining testosterone in males and reduced total testosterone is considered a cardiovascular risk factor. In the present study, the prevalence of hypogonadism in men who had suffered ischaemic stroke was evaluated along with the efficacy of testosterone undecanoate injections (TU) in patients with testosterone deficiency and type-2 diabetes (T2DM) in the acute phase of hemispheric ischaemic stroke. Hypogonadism was present in 66.3% of patients with ischaemic stroke, 50% with T2DM, and 26.3% without T2DM, respectively. TU treatment, at both the 2 and 5-year observation points, demonstrated significant improvements in biochemical, physical, and mental parameters. This supports that testosterone deficiency is a contributing factor in ischaemic events and that long-term testosterone therapy could play an important role in patient recovery.

Efficacy and Safety of Testosterone Treatment in Men: An Evidence Report for a Clinical Practice Guideline by the American College of Physicians

BACKGROUND

Testosterone treatment rates in adult men have increased in the United States over the past 2 decades.

PURPOSE

To assess the benefits and harms of testosterone treatment for men without underlying organic causes of hypogonadism.

DATA SOURCES

English-language searches of multiple electronic databases (January 1980 to May 2019) and reference lists from systematic reviews.

STUDY SELECTION

38 randomized controlled trials (RCTs) of at least 6 months' duration that evaluated transdermal or intramuscular testosterone therapies versus placebo or no treatment and reported prespecified patient-centered outcomes, as well as 20 long-term observational studies, U.S. Food and Drug Administration review data, and product labels that reported harms information.

DATA EXTRACTION

Data extraction by a single investigator was confirmed by a second, 2 investigators assessed risk of bias, and evidence certainty was determined by consensus.

DATA SYNTHESIS

Studies enrolled mostly older men who varied in age, symptoms, and testosterone eligibility criteria. Testosterone therapy improved sexual functioning and quality of life in men with low testosterone levels, although effect sizes were small (low- to moderate-certainty evidence). Testosterone therapy had little to no effect on physical functioning, depressive symptoms, energy and vitality, or cognition. Harms evidence reported in trials was judged to be insufficient or of low certainty for most harm outcomes. No trials were powered to assess cardiovascular events or prostate cancer, and trials often excluded men at increased risk for these conditions. Observational studies were limited by confounding by indication and contraindication.

LIMITATION

Few trials exceeded a 1-year duration, minimum important outcome differences were often not established or reported, RCTs were not powered to assess important harms, few data were available in men aged 18 to 50 years, definitions of low testosterone varied, and study entry criteria varied.

CONCLUSION

In older men with low testosterone levels without well-established medical conditions known to cause hypogonadism, testosterone therapy may provide small improvements in sexual functioning and quality of life but little to no benefit for other common symptoms of aging. Long-term efficacy and safety are unknown.

PRIMARY FUNDING SOURCE

American College of Physicians. (PROSPERO: CRD42018096585).

Testosterone replacement therapy and cardiovascular risk

Testosterone is the main male sex hormone and is essential for the maintenance of male secondary sexual characteristics and fertility. Androgen deficiency in young men owing to organic disease of the hypothalamus, pituitary gland or testes has been treated with testosterone replacement for decades without reports of increased cardiovascular events. In the past decade, the number of testosterone prescriptions issued for middle-aged or older men with either age-related or obesity-related decline in serum testosterone levels has increased exponentially even though these conditions are not approved indications for testosterone therapy. Some retrospective studies and randomized trials have suggested that testosterone replacement therapy increases the risk of cardiovascular disease, which has led the FDA to release a warning statement about the potential cardiovascular risks of testosterone replacement therapy. However, no trials of testosterone replacement therapy published to date were designed or adequately powered to assess cardiovascular events; therefore, the cardiovascular safety of this therapy remains unclear. In this Review, we provide an overview of epidemiological data on the association between serum levels of endogenous testosterone and cardiovascular disease, prescription database studies on the risk of cardiovascular disease in men receiving testosterone therapy, randomized trials and meta-analyses evaluating testosterone replacement therapy and its association with cardiovascular events and mechanistic studies on the effects of testosterone on the cardiovascular system. Our aim is to help clinicians to make informed decisions when considering testosterone replacement therapy in their patients.

Systemic effects of the hormonal treatment of male hypogonadism with preliminary indications for the management of COVID-19 patients

Male hypogonadism, defined as an inadequate production of testosterone (T), is associated with a greater morbidity and mortality. Epidemiological studies identified T deficiency as a risk factor for cardiovascular disease. Also, low serum T levels impact on glucose homeostasis through a worse glucose uptake, utilization, and disposal, and the general negative impact on metabolism. The aim of this review is to provide a comprehensive and updated overview of the effects of T replacement therapy on metabolic and cardiovascular systems and prostate tissue in patients with hypogonadism, including molecular mechanisms through which T exerts its actions. Furthermore, recent findings on novel coronavirus disease (COVID-19) epidemiology have shown a greater mortality in male compared with female patients and a role of T in promoting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection of the host cells has been demonstrated. Hence, the secondary aim of this review is to provide preliminary indications on the management in patients with COVID-19.

Testosterone and Cardiovascular Risk: Meta-Analysis of Interventional Studies

BACKGROUND

The relationship between testosterone (T) and cardiovascular (CV) risk in men is conflicting.

AIM

To verify whether T therapy (TTh) represents a possible risk factor for CV morbidity and mortality.

METHODS

We conducted a random effect meta-analysis considering all available data from pharmaco-epidemiological studies as well as randomized placebo-controlled trials (RCTs).

OUTCOMES

CV mortality and morbidity were investigated.

RESULTS

After screening, 15 pharmaco-epidemiological and 93 RCT studies were considered. The analysis of pharmaco-epidemiological studies documented that TTh reduces overall mortality and CV morbidity. Conversely, in RCTs, TTh had no clear effect, either beneficial or detrimental, on the incidence of CV events. However, a protective role of TTh on CV morbidity was observed when studies enrolling obese (body mass index >30 kg/m²) patients were scrutinized (Mantel-Haenszel odds ratio 0.51 [95% CI 0.27-0.96]; P = .04), although this association disappeared when only high-quality RCTs were considered (Mantel-Haenszel odds ratio 0.64 [95% CI 0.22-1.88]; P = .42). Finally, an increased risk of CV diseases was observed in RCTs when T preparations were prescribed at dosages above those normally recommended, or when frail men were considered.

CLINICAL IMPLICATIONS

Pharmaco-epidemiological studies showed that TTh might reduce CV risk, but this effect was not confirmed when RCTs were considered.

STRENGTHS & LIMITATIONS

Meta-analysis of pharmaco-epidemiological studies indicates that TTh reduces overall mortality and CV morbidity. In addition, even in RCTs, a protective role of TTh on CV morbidity was envisaged when studies enrolling obese (body mass index >30 kg/m²) patients were considered. Pharmaco-epidemiological studies should be considered with caution due to the lack of completeness of follow-up and of the management of missing data. In addition, properly powered placebo-controlled RCTs with a primary CV end point, in men with late-onset hypo-gonadism, are not yet available. Finally, the duration of all studies evaluated in the present meta-analysis is relatively short, reaching a maximum of 3 years.

CONCLUSIONS

Data from RCTs suggest that treatment with T is not effective in reducing CV risk, however, when TTh is correctly applied, it is not associated with an increase in CV risk and it may have a beneficial effect in some sub-populations. Corona G, Rastrelli G, Di Pasquale G, et al. Testosterone and Cardiovascular Risk: Meta-Analysis of Interventional Studies. J Sex Med 2018;15:820-838.

Testosterone and the Heart

The development of a subnormal level of testosterone (T) is not universal in ageing men, with 75% of men retaining normal levels. However, a substantial number of men do develop T deficiency (TD), with many of them carrying a portfolio of cardiovascular (CV) risk factors, including type 2 diabetes (T2D) and the metabolic syndrome. TD increases the risk of CV disease (CVD) and the risk of developing T2D and the metabolic syndrome. The key symptoms suggesting low T are sexual in nature, including erectile dysfunction (ED), loss of night-time erections and reduced libido. Many men with heart disease, if asked, admit to ED being present; a problem that is often compounded by drugs used to treat CVD. A large number of studies and meta-analyses have provided evidence of the link between TD and an increase in CVD and total mortality. Patients with chronic heart failure (CHF) who have TD have a poor prognosis and this is associated with more frequent admissions and increased mortality compared with those who do not have TD. Conversely, in men with symptoms and documented TD, T therapy has been shown to have beneficial effects, namely improvement in exercise capacity in patients with CHF, improvement of myocardial ischaemia and coronary artery disease. Reductions in BMI and waist circumference, and improvements in glycaemic control and lipid profiles, are observed in T-deficient men receiving T therapy. These effects might be expected to translate into benefits and there are more than 100 studies showing CV benefit or improved CV risk factors with T therapy. There are flawed retrospective and prescribing data studies that have suggested increased mortality in treated men, which has led to regulatory warnings, and one placebo-controlled study demonstrating an increase in coronary artery non-calcified and total plaque volumes in men treated with T, which is open for debate. Men with ED and TD who fail to respond to phosphodiesterase type 5 (PDE5) inhibitors can be salvaged by treating the TD. There are data to suggest that T and PDE5 inhibitors may act synergistically to reduce CV risk.

Advances in small-molecule therapy for managing angina pectoris in the elderly

Introduction: As our population ages, the prevalence of angina is growing, leading to increased morbidity and decreased quality of life. The management of angina in the elderly is challenging due to drug intolerance and/or drug resistance as well as frailty. Over the past decades, many new therapeutic small molecules have been investigated for the management of angina. Although none of these studies have specifically focused on the therapies for the elderly, they offer promising new avenues for the treatment of angina in the elderly. Areas covered: Herein, the authors provide a review of the recently published literature on the use of small-molecule therapies for angina management in the elderly and provide a brief overview of these therapies. Expert opinion: A variety of therapeutic classes of existing and newer small molecules are emerging for the management of angina in the elderly. An individualized approach to the management of angina in this growing population is critical for good outcomes. Many small molecules are in their initial stages of clinical use, and further research should be conducted on their utility, especially in the elderly.

Randomized controlled trials - mechanistic studies of testosterone and the cardiovascular system

Testosterone deficiency is common in men with cardiovascular disease (CVD), and randomized placebo-controlled trials (RCTs) have reported beneficial effects of testosterone therapy on exercise-induced cardiac ischemia in chronic stable angina, functional exercise capacity, maximum oxygen consumption during exercise (VO_2max) and muscle strength in chronic heart failure (CHF), shortening of the Q-T interval, and improvement of some cardiovascular risk factors. Testosterone deficiency is associated with an adverse CV risk profile and mortality. Clinical and scientific studies have provided mechanistic evidence to support and explain the findings of the RCTs. Testosterone is a rapid-onset arterial vasodilator within the coronary circulation and other vascular beds including the pulmonary vasculature and can reduce the overall peripheral systemic vascular resistance. Evidence has demonstrated that testosterone mediates this effect on vascular reactivity through calcium channel blockade (L-calcium channel) and stimulates potassium channel opening by direct nongenomic mechanisms. Testosterone also stimulates repolarization of cardiac myocytes by stimulating the ultra-rapid potassium channel-operated current. Testosterone improves cardiac output, functional exercise capacity, VO_2max and vagally mediated arterial baroreceptor cardiac reflex sensitivity in CHF, and other mechanisms. Independent of the benefit of testosterone on cardiac function, testosterone substitution may also increase skeletal muscle glucose metabolism and enhance muscular strength, both factors that could contribute to the improvement in functional exercise capacity may include improved glucose metabolism and muscle strength. Testosterone improves metabolic CV risk factors including body composition, insulin resistance, and hypercholesterolemia by improving both glucose utilization and lipid metabolism by a combination of genomic and nongenomic actions of glucose uptake and utilization expression of the insulin receptor, glucose transporters, and expression on regulatory enzymes of key metabolic pathways. The effect on high-density lipoprotein-cholesterol (HDL-C) differs between studies in that it has been found to fall, rise, or have no change in levels. Testosterone replacement can suppress the levels of circulating pro-inflammatory cytokines and stimulate the production of interleukin-10 (IL-10) which has anti-inflammatory and anti-atherogenic actions in men with CVD. No effect on C-reactive protein has been detected. No adverse effects on clotting factors have been detected. RCTs have not clearly demonstrated any significant evidence that testosterone improves or adversely affects the surrogate markers of atherosclerosis such as reduction in carotid intima thickness or coronary calcium deposition. Any effect of testosterone on prevention or amelioration of atherosclerosis is likely to occur over years as shown in statin therapy trials and not months as used in testosterone RCTs. The weight of evidence from long-term epidemiological studies supports a protective effect as evidenced by a reduction in major adverse CV events (MACEs) and mortality in studies which have treated men with testosterone deficiency. No RCT where testosterone has been replaced to the normal healthy range has reported a significant benefit or adverse effect on MACE nor has any recent meta-analysis.

An update on heart disease risk associated with testosterone boosting medications

INTRODUCTION

The cardiovascular (CV) safety of testosterone replacement therapy (TRT) remains a crucial issue in the management of subjects with late-onset hypogonadism. The authors systematically reviewed and discussed the available evidence focusing our analysis on heart-related issues.

AREAS COVERED

All the available data from prospective observational studies evaluating the role endogenous T levels on the risk of acute myocardial infarction (AMI) were collected and analyzed. In addition, the impact of TRT on heart-related diseases, as derived from pharmaco-epidemiological studies as well as from randomized placebo-controlled trials (RCTs), was also investigated.

EXPERT OPINION

Available evidence indicates that endogenous low T represents a risk factor of AMI incidence and its related mortality. TRT in hypogonadal patients is able to improve angina symptoms in subjects with ischemic heart diseases and exercise ability in patients with heart failure (HF). In addition, when prescribed according to the recommended dosage, TRT does not increase the risk of heart-related events.

Testosterone, myocardial function, and mortality

The cardiovascular system is particularly sensitive to androgens, but some controversies exist regarding the effect of testosterone on the heart. While among anabolic abusers, cases of sudden cardiac death have been described, recently it was reported that low serum level of testosterone was correlated with increased risk of cardiovascular diseases (CVD) and mortality rate. This review aims to evaluate the effect of testosterone on myocardial tissue function, coronary artery disease (CAD), and death. Low testosterone level is associated with increased incidence of CAD and mortality. Testosterone administration in hypogonadal elderly men and women has a positive effect on cardiovascular function and improved clinical outcomes and survival time. Although at supraphysiologic doses, androgen may have a toxic effect, and at physiological levels, testosterone is safe and exerts a beneficial effect on myocardial function including mechanisms at cellular and mitochondrial level. The interaction with free testosterone and estradiol should be considered. Further studies are necessary to better understand the interaction mechanisms for an optimal androgen therapy in CVD.

Association between serum levels of testosterone and biomarkers of subclinical atherosclerosis

OBJECTIVE

To investigate the association between serum levels of testosterone and biomarkers of subclinical atherosclerosis based on data from 119 middle-aged men of the general population.

METHODS

Testosterone, Apolipoprotein A-1 (ApoA-1), Apolipoprotein B (ApoB), Apolipoprotein B-to-Apolipoprotein A-1 ratio (ApoB-to-ApoA-1), high-sensitive C-reactive protein (hsCRP), and fibrinogen levels were measured. Data were also gathered based on age, BMI, waist circumference, smoking, alcohol consumption, and family history of cardiovascular diseases. Men were classified into two groups based on testosterone levels: hypogonadal (testosterone ≤12 nmol/L) and eugonadal men (testosterone >12 nmol/L).

RESULTS

When compared to eugonadal, the hypogonadal men were significantly older (56 years vs. 55 years, p = .03), had greater BMI (28 kg/cm² vs. 26 kg/cm², p = .01), and higher waist circumference (104 cm vs. 100 cm, p = .01). Moreover, ApoB, ApoB-to-ApoA-1 ratio, and hsCRP were significantly higher in hypogonadal men compared to eugonadal men (1.1 g/L vs. 1.0 g/L, p = .03), (0.8 vs. 0.7, p = .03), (3.3 mg/L vs. 2.0 mg/L, p = .01), respectively. On the other hand, ApoA-1 and fibrinogen levels did not differ significantly between groups (p > .05). In an adjusted multivariate regression analysis model, only ApoB showed a significant negative association with testosterone levels (β = -0.01; 95% CI = -0.02, -1.50; p = .04).

CONCLUSION

Testosterone levels showed an inverse relation to ApoB, a biomarker implicated in subclinical atherosclerosis. These findings support the hypothesis that low testosterone levels play a role in atherosclerosis.

Testosterone treatment in older men: clinical implications and unresolved questions from the Testosterone Trials

A decrease in the concentration of circulating testosterone in many older men is a biomarker and possibly a rectifiable contributing factor to ill health. Low circulating testosterone concentration has been associated with cardiovascular disease, reduced cognition, fracture risk, and anaemia. However, randomised placebo-controlled trials are essential to clarify the benefits and possible risks of testosterone treatment in men without hypothalamic, pituitary, or testicular disease. The Testosterone Trials (T-Trials) were a coordinated set of trials that, following a screening-to-enrolment ratio of 65:1, randomly assigned 790 men aged 65 years or older who had a baseline testosterone concentration of less than 9·54 nmol/L and symptoms consistent with hypogonadism, but no recognisable hypothalamic-pituitary-testicular axis pathology, to daily transdermal testosterone or placebo for 12 months. In the main trial, testosterone treatment resulted in a modest benefit for sexual function, whereas the other primary outcomes of vitality and physical function were not met. Data from concomitant substudies raised a possible concern over changes in coronary plaque volume, showed a neutral effect on memory and other cognitive functions, and revealed improvements in volumetric bone mineral density and anaemia. Although insufficient to alter the existing clinical equipoise, the T-Trials provided substantial new data on organ-specific outcomes for testosterone treatment in older men. Further clinical trials are necessary to determine whether testosterone treatment will translate into patient-valued health outcomes and to clarify effects on the cardiovascular system.

Trials of testosterone replacement reporting cardiovascular adverse events

The numbers of testosterone prescriptions written have increased several-fold worldwide, but the incidence of pathological hypogonadism due to hypothalamic, pituitary, and testicular disease has remained unchanged. Most of these prescriptions are being dispensed to middle-aged and older men who have experienced age-related decline in serum testosterone levels; a subset of the population in which benefits of testosterone replacement is at best, modest. Recently, some randomized controlled trials have reported increased cardiovascular events in men (mainly older men and those with prevalent cardiovascular disease) with testosterone use, and a few recent meta-analyses have confirmed these findings. In this review, we discuss trials of testosterone therapy that have reported higher cardiovascular events, relevant trials that have not reported increased cardiovascular events and large trials that have focused on cardiovascular risk (mainly atherosclerosis progression) as their main outcome. We also review findings from meta-analyses that have evaluated cardiovascular events in various testosterone trials. Finally, we discuss some potential mechanisms by which testosterone use might result in an increased cardiovascular risk. As none of the trials conducted to date were adequately powered to evaluate cardiovascular events, no firm conclusions can be drawn regarding the cardiovascular safety of testosterone therapy at this time. In the interim, we hope that this review will help practitioners make informed decisions regarding the care of their patients.

Testosterone and Cardiovascular Health

There is an ongoing debate in the medical community regarding the effects of testosterone on cardiovascular (CV) health. For decades, there has been conflicting evidence regarding the association of endogenous testosterone levels and CV disease (CVD) events that has resulted in much debate and confusion among health care providers and patients alike. Testosterone therapy has become increasingly widespread, and after the emergence of studies that reported increased CVD events in patients receiving testosterone therapy, the US Food and Drug Administration (FDA) released a warning statement about testosterone and its potential risk regarding CV health. Some of these studies were later found to be critically flawed, and some experts, including the American Association of Clinical Endocrinologists and an expert panel regarding testosterone deficiency and its treatment, reported that some of the FDA statements regarding testosterone therapy were lacking scientific evidence. This article summarizes the current evidence regarding the relationship between testosterone (endogenous and supplemental) and CV health. A literature review was conducted via search using PubMed and specific journal databases, including the New England Journal of Medicine and the Journal of the American College of Cardiology. Key search terms included testosterone and cardiovascular health, coronary artery disease, heart failure, androgen deprivation therapy, intima-media thickness, and adrenal androgens. Initial study selection was limited to publications within the past 10 years (January 1, 2007, through December 31, 2016); however, key publications outside of this time frame were selected if they provided important quantitative data or historical perspectives for the review of this topic. The search was further supplemented by reviewing references in selected articles.

Recent Progress in Vascular Aging: Mechanisms and Its Role in Age-related Diseases

As with many age-related diseases including vascular dysfunction, age is considered an independent and crucial risk factor. Complicated alterations of structure and function in the vasculature are linked with aging hence, understanding the underlying mechanisms of age-induced vascular pathophysiological changes holds possibilities for developing clinical diagnostic methods and new therapeutic strategies. Here, we discuss the underlying molecular mediators that could be involved in vascular aging, e.g., the renin-angiotensin system and pro-inflammatory factors, metalloproteinases, calpain-1, monocyte chemoattractant protein-1 (MCP-1) and TGFβ-1 as well as the potential roles of testosterone and estrogen. We then relate all of these to clinical manifestations such as vascular dementia and stroke in addition to reviewing the existing clinical measurements and potential interventions for age-related vascular dysfunction.

Role of Testosterone in the Treatment of Cardiovascular Disease

Cardiovascular disease (CVD) is the most prevalent non-communicable cause of death worldwide. Testosterone is a sex hormone that is predominant in males but also occurs in lower concentrations in females. It has effects directly on the blood vessels of the cardiovascular system and on the heart, as well as effects on risk factors for CVD. Serum testosterone concentrations are known to decrease with age and reduced testosterone levels are linked to premature coronary artery disease, unfavourable effects on CVD risk factors and increased risk of cardiovascular mortality independent of age. A significant number of men with heart failure demonstrate reduced serum testosterone concentrations and there is early evidence suggesting that low testosterone levels affect cardiac repolarisation. Any association between endogenous testosterone concentrations and CVD in women has yet to be established. Testosterone replacement is used to treat men with hypogonadism but also has cardiovascular effects. This review will present the current evidence, expert opinion and controversies around the role of testosterone in the pathophysiology of CVD and surrounding the use of testosterone treatment and its effects on the cardiovascular system and CVD.

Association between exogenous testosterone and cardiovascular events: an overview of systematic reviews

Given the conflicting evidence regarding the association between exogenous testosterone and cardiovascular events, we systematically assessed published systematic reviews for evidence of the association between exogenous testosterone and cardiovascular events. We searched PubMed, MEDLINE, Embase, Cochrane Collaboration Clinical Trials, ClinicalTrials.gov, and the US Food and Drug Administration website for systematic reviews of randomised controlled trials published up to July 19, 2016. Two independent reviewers screened 954 full texts from 29 335 abstracts to identify systematic reviews of randomised controlled trials in which the cardiovascular effects of exogenous testosterone on men aged 18 years or older were examined. We extracted data for study characteristics, analytic methods, and key findings, and applied the AMSTAR (A Measurement Tool to Assess Systematic Reviews) checklist to assess methodological quality of each review. Our primary outcome measure was the direction and magnitude of association between exogenous testosterone and cardiovascular events. We identified seven reviews and meta-analyses, which had substantial clinical heterogeneity, differing statistical methods, and variable methodological quality and quality of data abstraction. AMSTAR scores ranged from 3 to 9 out of 11. Six systematic reviews that each included a meta-analysis showed no significant association between exogenous testosterone and cardiovascular events, with summary estimates ranging from 1·07 to 1·82 and imprecise confidence intervals. Two of these six meta-analyses showed increased risk in subgroup analyses of oral testosterone and men aged 65 years or older during their first treatment year. One meta-analysis showed a significant association between exogenous testosterone and cardiovascular events, in men aged 18 years or older generally, with a summary estimate of 1·54 (95% CI 1·09-2·18). Our optimal information size analysis showed that any randomised controlled trial aiming to detect a true difference in cardiovascular risk between treatment groups receiving exogenous testosterone and their controls (with a two-sided p value of 0·05 and a power of 80%) would require at least 17 664 participants in each trial group. Therefore, given the challenge of adequately powering clinical trials for rare outcomes, rigorous observational studies are needed to clarify the association between testosterone-replacement therapy and major adverse cardiovascular outcomes.

Experimental and early investigational drugs for angina pectoris

INTRODUCTION

Ischemic heart disease (IHD) is a major cause of death and disability among Western countries and angina pectoris is the most prevalent symptomatic manifestation. Strategies to improve management of chronic stable angina are a priority. Areas covered: A comprehensive review was conducted using the Medline and Cochrane databases as well as the clinical trial databases in the United States and Europe. Traditional therapies for angina will be discussed. This review particularly emphasizes investigational therapies for angina (including pharmacological agents, cell and gene based therapies, and herbal medications). Expert opinion: There has been renewed interest in older anti-angina agents (e.g., perhexiline, amiodarone, and phosphodiestrase-5 inhibitors). Other anti-inflammatory agents (e.g., allopurinol and febuxostat) are currently undergoing evaluation for angina therapy. Therapeutic angiogenesis continues to face some challenges. Future trials should evaluate the optimum patient population that would benefit from this form of therapy.

Testosterone Replacement Therapy and Mortality in Older Men

While US testosterone prescriptions have tripled in the last decade with lower trends in Europe, debate continues over the risks, benefits and appropriate use of testosterone replacement therapy (TRT). Several authors blame advertising and the availability of more convenient formulations, whilst others have pointed out that the routine testing of men with erectile dysfunction (ED) (a significant marker of cardiovascular risk) and those with diabetes would inevitably increase the diagnosis of hypogonadism and lead to an increase in totally appropriate prescribing. They commented that this was merely an appropriate correction of previous under-diagnosis and under-treatment in line with evidence based guidelines. It is unlikely that persuasive advertising or convenient formulations could grow a market over such a sustained period if the treatment was not effective. Urologists and primary care physicians are the most frequent initiators of TRT usually for ED. Benefits are clearly established for sexual function, increase in lean muscle mass and strength, mood and cognitive function, with a possible reduction in frailty and osteoporosis. There remains no evidence that TRT is associated with increased risk of prostate cancer or symptomatic benign prostatic hyperplasia, yet the decision to initiate and continue therapy is often decided by urologists. The cardiovascular issues associated with TRT have been clarified by recent studies showing that therapy associated with clear increases in serum testosterone levels to the normal range is associated with reduced all-cause mortality. Studies reporting to show increased risk have been subject to flawed designs with inadequate baseline diagnosis and follow-up testing. Effectively, they have compared non-treated patients with under-treated or non-compliant subjects involving a range of different therapy regimes. Recent evidence suggests long-acting injections may be associated with decreased cardiovascular risk, but the transdermal route may be associated with potentially relatively greater risk because of conversion to dihydrotestosterone by the effect of 5-alpha reductase in skin. The multiple effects of TRT may add up to a considerable benefit to the patient that might be underestimated by the physician primarily concerned with his own specialty. In a response to concerns about the possible risks associated with inappropriate prescribing expressed by Public Citizen, the Food and Drug Administration (FDA) published a complete refutation of all the concerns, only to issue a subsequent bulletin of concern over inappropriate use, whilst confirming the benefits in treating men with established testosterone deficiency. No additional evidence was provided for this apparent change of opinion, but longer term safety data on testosterone products were strongly suggested. In contrast, the European Medicines Agency (EMA), in November 2014, concluded that “there is no consistent evidence of increased cardiovascular risk with testosterone products”. This paper explores the most recent evidence surrounding the benefits and risks associated with TRT.

Treatment of Men for “Low Testosterone”: A Systematic Review

Testosterone products are recommended by some prescribers in response to a diagnosis or presumption of “low testosterone” (low-T) for cardiovascular health, sexual function, muscle weakness or wasting, mood and behavior, and cognition. We performed a systematic review of 156 eligible randomized controlled trials in which testosterone was compared to placebo for one or more of these conditions. We included studies in bibliographic databases between January 1, 1950 and April 9, 2016, and excluded studies involving bodybuilding, contraceptive effectiveness, or treatment of any condition in women or children. Studies with multiple relevant endpoints were included in all relevant tables. Testosterone supplementation did not show consistent benefit for cardiovascular risk, sexual function, mood and behavior, or cognition. Studies that examined clinical cardiovascular endpoints have not favored testosterone therapy over placebo. Testosterone is ineffective in treating erectile dysfunction and controlled trials did not show a consistent effect on libido. Testosterone supplementation consistently increased muscle strength but did not have beneficial effects on physical function. Most studies on mood-related endpoints found no beneficial effect of testosterone treatment on personality, psychological well-being, or mood. The prescription of testosterone supplementation for low-T for cardiovascular health, sexual function, physical function, mood, or cognitive function is without support from randomized clinical trials.

Testosterone and Cardiovascular Disease

Testosterone (T) is the principal male sex hormone. As men age, T levels typically fall. Symptoms of low T include decreased libido, vasomotor instability, and decreased bone mineral density. Other symptoms may include depression, fatigue, erectile dysfunction, and reduced muscle strength/mass. Epidemiology studies show that low levels of T are associated with more atherosclerosis, coronary artery disease, and cardiovascular events. However, treating hypogonadism in the aging male has resulted in discrepant results in regard to its effect on cardiovascular events. Emerging studies suggest that T may have a future role in treating heart failure, angina, and myocardial ischemia. A large, prospective, long-term study of T replacement, with a primary endpoint of a composite of adverse cardiovascular events including myocardial infarction, stroke, and/or cardiovascular death, is needed. The Food and Drug Administration recently put additional restrictions on T replacement therapy labeling and called for additional studies to determine its cardiac safety.