Testosterone: A Novel Therapeutic Approach in Chronic Heart Failure?⁎⁎Editorials published in the Journal of the American College of Cardiologyreflect the views of the authors and do not necessarily represent the views of JACCor the American College of Cardiology

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 relationship between serum sex hormone and cardiac echocardiographic findings in healthy men

Serum sex hormones are known to be associated with cardiovascular disease (CVD), but effects in healthy men on cardiac function have not been well quantified. The authors sought to evaluate an association of sex hormones with cardiac structure and function. Study participants were 857 Korean men without significant cardiovascular diseases participating in the Healthy Twin Study. We estimated the associations of total testosterone (TT) and sex hormone-binding globulin (SHBG) with cardiac structure and function measured by echocardiography using a linear mixed regression model with consideration of random and fixed effects of covariates. The ratio of peak early diastolic velocity of mitral inflow over peak early diastolic mitral annular velocity (E/e') and left atrial volume index (LAVI), functional parameters reflecting left ventricle (LV) filling pressure, were inversely associated with TT even after further cross-adjustment for SHBG level. There was a positive association between LAVI and SHBG, regardless of TT adjustment. These findings suggest that serum testosterone level is positively associated with LV diastolic function independent of SHBG level.

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'.

Cardiovascular risk and testosterone - from subclinical atherosclerosis to lipoprotein function to heart failure

The cardiovascular (CV) benefit and safety of treating low testosterone conditions is a matter of debate. Although testosterone deficiency has been linked to a rise in major adverse CV events, most of the studies on testosterone replacement therapy were not designed to assess CV risk and thus excluded men with advanced heart failure or recent history of myocardial infarction or stroke. Besides considering observational, interventional and prospective studies, this review article evaluates the impact of testosterone on atherosclerosis process, including lipoprotein functionality, progression of carotid intima media thickness, inflammation, coagulation and thromboembolism, quantification of plaque volume and vascular calcification. Until adequately powered studies evaluating testosterone effects in hypogonadal men at increased CV risk are available (TRAVERSE trial), clinicians should ponder the use of testosterone in men with atherosclerotic cardiovascular disease and discuss benefit and harms with the patients.

Effects of lifelong testosterone exposure on health and disease using Mendelian randomization

Testosterone products are prescribed to males for a variety of possible health benefits, but causal effects are unclear. Evidence from randomized trials are difficult to obtain, particularly regarding effects on long-term or rare outcomes. Mendelian randomization analyses were performed to infer phenome-wide effects of free testosterone on 461 outcomes in 161,268 males from the UK Biobank study. Lifelong increased free testosterone had beneficial effects on increased bone mineral density, and decreased body fat; adverse effects on decreased HDL, and increased risks of prostate cancer, androgenic alopecia, spinal stenosis, and hypertension; and context-dependent effects on increased hematocrit and decreased C-reactive protein. No benefit was observed for type 2 diabetes, cardiovascular or cognitive outcomes. Mendelian randomization suggests benefits of long-term increased testosterone should be considered against adverse effects, notably increased prostate cancer and hypertension. Well-powered randomized trials are needed to conclusively address risks and benefits of testosterone treatment on these outcomes.

Plasma testosterone and arrhythmic events in male patients with arrhythmogenic right ventricular cardiomyopathy

AIMS

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with life-threatening ventricular arrhythmia and progressive ventricular dysfunction. Previous studies suggested that sex hormones play an important role in the onset and prognosis of ARVC. This study aimed to investigate the role of testosterone in predicting major adverse cardiac events in the Chinese ARVC cohort.

METHODS AND RESULTS

Ninety-nine ARVC patients (median age, 40 years; 70.7% male) and 96 healthy controls (median age, 41 years; 62.5% male) were enrolled. The circulating levels of testosterone were measured by enzyme-linked immunosorbent assays (ELISA). The median follow-up time of all ARVC male patients was 17 months (interquartile range/IQR 9-29). Cox proportional hazards regression was used to analyse the effect of plasma testosterone and other well-described risk factors on malignant arrhythmic events in male ARVC patients. The male ARVC patients had significantly elevated levels of total testosterone [TT, 6.390 (4.438-8.768) ng/mL vs. 3.617 (2.073-4.479) ng/mL, P < 0.0001, data shown as the median with IQR], bioavailable testosterone [BT, 4.11 (1.990-6.545) ng/mL vs. 1.32 (0.7965-2.0350) ng/mL, P < 0.0001, median with IQR], and free testosterone [FT, 0.2055 (0.1000-0.4073) ng/mL vs. 0.0768 (0.0405-0.1105) ng/mL, P < 0.0001, median with IQR] than healthy male volunteer, whereas no differences were observed among female counterparts. There was no significant correlation between the baseline clinical characteristics and testosterone levels in male ARVC patients (Spearman's correlation test, P > 0.05). During the follow-up, the levels of testosterone were higher in male patients who experienced malignant arrhythmic events (N = 22) than in those who did not (N = 25) [TT, 9.034 (7.222-15.370) ng/mL vs. 4.633 (3.363-6.375) ng/mL, P < 0.001; BT, 7.485 (2.070-9.163) ng/mL vs. 3.300 (1.685-4.690) ng/mL, P < 0.05; FT, 0.453 (0.221-0.758) ng/mL vs. 0.161 (0.075-0.337) ng/mL P < 0.05, data expressed as median (IQR) and adjusted by Dunn's multiple comparisons test], whereas such distinction was not observed among patients with significant structural progression events (N = 16). Through multivariable adjustments, the Cox regression analysis showed the level of plasma total testosterone (HR = 1.325, 95% confidence interval = 1.171-1.498, P < 0.001) was an independent predictor for malignant arrhythmic events.

CONCLUSIONS

The levels of plasma testosterone in ARVC male patients are higher than those in healthy males. Testosterone level, without relation to the baseline cardiac function and future significant structural progression events, is a strong predictor of future adverse arrhythmic events in male patients with ARVC. Therefore, our results suggest that testosterone may be a useful biomarker in arrhythmic risk prediction in the ARVC.

Metabolic Dysfunction in Continuous-Flow Left Ventricular Assist Devices Patients and Outcomes

Background

Metabolic impairment is common in heart failure patients. Continuous‐flow left ventricular assist devices (CF‐LVADs) improve hemodynamics and outcomes in patients with advanced heart failure; however, the effect of CF‐LVADs on metabolic status is unknown. This study aims to evaluate the changes in metabolic status following CF‐LVAD implantation and measure the correlation of metabolic status with outcomes.

Methods and Results

Prospective data on CF‐LVAD patients were obtained. Metabolic evaluation, including hemoglobin A1C, free and total testosterone, thyroid‐stimulating hormone (TSH), and free T4, was obtained before and at multiple time points following implantation. Patients with nonelevated thyroid‐stimulating hormone and normal hemoglobin A1C and testosterone levels were defined as having normal metabolic status. Baseline characteristics, hemodynamics, and outcomes were collected. One hundred six patients were studied, of which 56 had paired data at baseline and 1‐ to 3‐month follow‐up. Before implantation, 75% of patients had insulin resistance, 86% of men and 39% of women had low free testosterone, and 44% of patients had abnormal thyroid function. There was a significant improvement in hemoglobin A1C, free testosterone, and thyroid‐stimulating hormone following implantation (P<0.001 for all). Patients with normal hemoglobin A1C (<5.7%) following implantation had higher 1‐year survival free of heart failure readmissions (78% versus 23%; P<0.001). Patients with normal metabolic status following implantation also had higher 1‐year survival free of heart failure readmissions (92% versus 54%; P=0.04).

Conclusions

Metabolic dysfunction is highly prevalent in advanced heart failure patients and improves after CF‐LVAD implantation. Normal metabolic status is associated with a significantly higher rate of 1‐year survival free of heart failure readmissions.

Testosterone Replacement Therapy in Deficient Patients With Chronic Heart Failure: A Randomized Double-Blind Controlled Pilot Study

BACKGROUND

Testosterone deficiency is associated with heart failure (HF) progression and poor prognosis. Testosterone therapy has been shown to improve exercise capacity in patients with chronic HF, but no trial has evaluated the impact of replacement in patients with demonstrated testosterone deficiency.

METHODS

Prospective, randomized, double-blind, placebo-controlled, and parallel-group trial comparing testosterone replacement with placebo in males with chronic HF with reduced ejection fraction (HFrEF) and testosterone deficiency (NCT01813201). Long-acting undecanoate testosterone at a fixed dose of 1000 mg was supplied by intramuscular injection at inclusion and then every 3 months. The placebo group received isotonic saline serum. Patients were randomly allocated 1:1 to testosterone or placebo while receiving optimal medical therapy, and the study was conducted for 12 months.

RESULTS

The final sample comprised 29 patients, 15 in the placebo group and 14 in the testosterone group (aged 65 ± 8, 62% with an ischemic etiology, left ventricular ejection fraction [LVEF] 30% ± 6%, 69% New York Heart Association functional [NYHA II]). After 12 months, testosterone replacement increased testosterone levels ( P = .002) but was not associated with benefit in terms of clinical symptoms and functional capacity including NYHA class, Framingham score, Minnesota Living Heart Failure Questionnaire, 6-minute walk test, or LVEF and N-terminal pro-B-type natriuretic peptide levels. No significant side effects associated with testosterone treatment were observed. No effects were found in other hormonal, metabolic, and bone turnover biomarkers.

CONCLUSION

In patients with HFrEF and testosterone deficiency, replacement therapy was not associated with any significant improvement.

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.

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.

Skeletal Muscle Changes in Chronic Cardiac Disease and Failure

Peak exercise performance in healthy man is limited not only by pulmonary or skeletal muscle function but also by cardiac function. Thus, abnormalities in cardiac function will have a major impact on exercise performance. Many cardiac diseases affect exercise performance and indeed for some cardiac conditions such as atherosclerotic heart disease, exercise testing is frequently used not only to measure functional capacity but also to make a diagnosis of heart disease, evaluate the efficacy of treatment, and predict prognosis. Early in the course of cardiac diseases, exercise performance will be minimally affected but with disease progression impairment in exercise capacity will become apparent. Ejection fraction, that is, the percent of blood volume ejected with each cardiac cycle is often used as a measure of cardiac performance but frequently there is a dissociation between the ejection fraction and exercise capacity in patients with heart disease. How abnormalities in cardiac function impacts the muscles, vasculature, and lungs to impact exercise performance will here be reviewed. The focus of this work will be on patients with systolic heart failure as the incidence and prevalence of heart failure is reaching epidemic proportions and heart failure is the end result of many other chronic cardiac diseases. The prognostic role of exercise and benefits of exercise training will also be discussed.

Outcomes of testosterone therapy in men with testosterone deficiency (TD): part II

Testosterone (T) deficiency (TD) is a common clinical condition, which contributes to co-morbidities including loss of muscle mass, increased fat mass, increased inflammation, insulin resistance, risk of vascular disease, sexual dysfunction, fatigue, depressed mood and reduced quality of life. T therapy attenuates inflammation, increases insulin sensitivity, muscle mass and reduces fat mass and adiposity. T therapy improves lipid profiles and endothelial function and reduces systolic and diastolic blood pressure. In addition, T therapy may reduce risk of vascular disease and mortality. T therapy improves bone mineral density and increases energy and vitality and improves mood and sexual function and overall quality of life. T therapy appears to be safe if treatment and monitoring are appropriately executed. The evidence available to date does not support alleged concerns regarding risk of cardiovascular disease and prostate cancer. Indeed, T therapy remains controversial. The data in the contemporary literature suggest that T therapy reduces cardiovascular risk and fears promoted by some recent studies should be re-evaluated. The cardiovascular risk and mortality with T therapy must await large prospective controlled clinical trials, which depend on many complex factors. Such studies may be prohibitive in the current environment due to logistical challenges, such as recruiting large number of men to be treated for long-durations with appropriate follow-up, requiring astronomical cost.

Metabolic and structural impairment of skeletal muscle in heart failure

Physiologic endurance exercise performance is primarily limited by cardiac function. In patients with heart failure, there is dissociation between cardiac performance and exercise capacity, suggesting a distinct role of abnormal peripheral organ function, including skeletal muscle function. The impact of heart failure upon skeletal muscle and exercise performance will be discussed with a focus on molecular, structural, and functional derangements in skeletal muscle of patients with heart failure.

Effect of testosterone undecanoate on hematological profiles, blood lipid and viscosity and plasma testosterone level in castrated rabbits

OBJECTIVE

The association between testosterone replacement therapy and cardiovascular risk remains controversial. Blood viscosity is a known individual risk factor for cardiovascular disease mortality. The objective of the present study was to investigate the effects of the long-acting injectable testosterone undecanoate (TU) on risk factors of cardiovascular disease.

METHODS

In total, 24 male New Zealand white rabbits (2.5 kg) were randomly divided into 3 groups of 8. Group 1 was used as control. Group 2 was castrated bilaterally and Group 3 was administrated with 6 mg/kg of TU at day 1 and 6 weeks after castration. Whole blood viscosity, total plasma testosterone, hemoglobin (Hb), hematocrit (Hct), fibrinogen (FBN), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were measured at baseline, 6 weeks and 18 weeks.

RESULTS

In the control group, whole blood viscosity and FBN were significantly increased at 6 and 18 weeks. Castration significantly increased the levels of TC, TG, HDL-C and LDL-C, but decreased Hct and Hb. In the TU injection group, whole blood viscosity was markedly decreased in all share rates, whereas the FBN level was increased. Hb and Hct showed a tendency for higher concentration at 6 weeks.

CONCLUSIONS

Long-acting injectable TU provides another reliable treatment option for testosterone replacement therapy. Moreover, the patients may receive additional beneficial effect in lowered whole blood viscosity.

Testosterone therapy: treatment of metabolic disturbances in heart failure

Heart failure (HF) is a complex progressive multisystem disease state with significant morbidity and mortality, which is not solely defined by pathology of the cardiovascular system but also is influenced by neurohormonal regulatory adjustments, peripheral cytokines, as well as hormonal and musculoskeletal dysfunction. Recent attention to the catabolic state found in patients with chronic heart failure has sparked interest in new potential targets for medical therapy. In particular, as many as 26% to 37% of men affected with HF have been found to be testosterone deficient. The severity of androgen deficiency has been shown to correlate with symptoms, functional class, and prognosis in patients with heart failure. Testosterone supplementation has been an accepted therapy in hypogonadal men with fatigue, muscle wasting, and sexual dysfunction for some time. Patients with severe HF show a similar constellation of symptoms and hypothetically would benefit from androgen replacement. Recent clinical studies have confirmed that functional, biochemical, and cardiopulmonary status in patients with HF have significant improvements when treated with testosterone supplementation. Symptomatic improvements may be obtainable in hypogonadal patients with HF who receive supplemental testosterone. This review seeks to outline the cardiovascular and peripheral effects of testosterone supplementation in patients with chronic HF.

Growth hormone and testosterone in heart failure therapy

IMPORTANCE OF THE FIELD

Heart failure is a progressive disease affecting millions of people worldwide. The disease carries a significantly high morbidity and mortality risk. There are multiple pharmaceutical options to decrease this risk and prolong survival; however, despite optimization of medical management, several patients still await heart transplant, the only definitive cure for heart failure. To slow the progression of disease preventing need for transplantation, improve clinical symptoms, and improve heart failure outcomes, there is a persistent need to discover new therapeutic strategies. Of interest, low growth hormone and testosterone levels have been associated with a worsening degree of heart failure. Many studies have begun to show a clinical improvement in heart failure symptoms when these levels are corrected with hormonal therapy. These findings, although mixed, are promising and indicate that both testosterone and growth hormone therapy should be considered as adjunctive therapy in advanced heart failure patients.

AREAS COVERED IN THIS REVIEW

This review discusses the physiology of both of these natural hormones, their therapeutic effects in heart failure and data from the published literature on studies using growth hormone or testosterone in patients with chronic heart failure. An extensive search of PubMed was conducted for topics on heart failure, growth hormone, insulin-like growth factor, testosterone, their physiology and pathophysiology, and trials in which they have been used as therapeutic interventions between 1989 and 2009.

WHAT THE READER WILL GAIN

The reader will gain an understanding of the intricate balance of both of these hormones in the disease state of heart failure. In addition, the trials conducted using these hormones in pharmacotherapy for heart failure are discussed along with proposed theories for interstudy variability.

TAKE HOME MESSAGE

Testosterone deficiency and growth hormone resistance are positively associated with a poor state of heart failure. Treatment of deficiency improves outcomes in heart failure; however, there is a significant paucity of data with regard to testosterone and heart failure as well as a significant amount of study variability with growth hormone and heart failure.

Differential actions of eplerenone and spironolactone on the protective effect of testosterone against cardiomyocyte apoptosis in vitro

INTRODUCTION AND OBJECTIVES

Testosterone deficiency is associated with a poor prognosis in patients with heart failure. It is not clear whether testosterone reduces cardiomyocyte apoptosis or whether the effect of spironolactone, an aldosterone receptor blocker with progestogenic and anti-androgen activity, differs from that of the selective aldosterone blocker eplerenone.

METHODS

Apoptosis induced by hyperosmotic stress in the embryonic rat heart cell line H9c2 was monitored by measuring cell viability, DNA fragmentation and caspase-3, -8 and -9 activation. The effect of testosterone was investigated in the presence or absence of spironolactone and eplerenone.

RESULTS

Exposure to sorbitol (0.6 M, 3 h) decreased cell viability and increased DNA fragmentation and caspase-3, -8 and -9 activation. These effects were all significantly reduced by testosterone, 100 nM (P< .01). Pretreatment with spironolactone, 10 .M, blocked the effects of testosterone, decreased cell viability (P< .01) and increased caspase activation (P< .01). In contrast, eplerenone, 10 .M, increased cell viability (P< .001) without altering the effect on caspase activation. These actions were not modified by the androgen receptor blocker flutamide. They were mediated by SAPK/JNK and ERK1/2 signaling pathways (P< .01).

CONCLUSIONS

Testosterone appears to have a protective effect against cardiomyocyte apoptosis which is antagonized by spironolactone but not by eplerenone. These effects await confirmation in in vivo models, but their presence could have clinical and therapeutic implications.