Endogenous sex hormones and the prospective association with cardiovascular disease and mortality in men: the Tromsø Study

Associations of Testosterone and Related Hormones With All-Cause and Cardiovascular Mortality and Incident Cardiovascular Disease in Men : Individual Participant Data Meta-analyses

BACKGROUND

Whether circulating sex hormones modulate mortality and cardiovascular disease (CVD) risk in aging men is controversial.

PURPOSE

To clarify associations of sex hormones with these outcomes.

DATA SOURCES

Systematic literature review to July 2019, with bridge searches to March 2024.

STUDY SELECTION

Prospective cohort studies of community-dwelling men with sex steroids measured using mass spectrometry and at least 5 years of follow-up.

DATA EXTRACTION

Independent variables were testosterone, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), dihydrotestosterone (DHT), and estradiol concentrations. Primary outcomes were all-cause mortality, CVD death, and incident CVD events. Covariates included age, body mass index, marital status, alcohol consumption, smoking, physical activity, hypertension, diabetes, creatinine concentration, ratio of total to high-density lipoprotein cholesterol, and lipid medication use.

DATA SYNTHESIS

Nine studies provided individual participant data (IPD) (255 830 participant-years). Eleven studies provided summary estimates (n = 24 109). Two-stage random-effects IPD meta-analyses found that men with baseline testosterone concentrations below 7.4 nmol/L (<213 ng/dL), LH concentrations above 10 IU/L, or estradiol concentrations below 5.1 pmol/L had higher all-cause mortality, and those with testosterone concentrations below 5.3 nmol/L (<153 ng/dL) had higher CVD mortality risk. Lower SHBG concentration was associated with lower all-cause mortality (median for quintile 1 [Q1] vs. Q5, 20.6 vs. 68.3 nmol/L; adjusted hazard ratio [HR], 0.85 [95% CI, 0.77 to 0.95]) and lower CVD mortality (adjusted HR, 0.81 [CI, 0.65 to 1.00]). Men with lower baseline DHT concentrations had higher risk for all-cause mortality (median for Q1 vs. Q5, 0.69 vs. 2.45 nmol/L; adjusted HR, 1.19 [CI, 1.08 to 1.30]) and CVD mortality (adjusted HR, 1.29 [CI, 1.03 to 1.61]), and risk also increased with DHT concentrations above 2.45 nmol/L. Men with DHT concentrations below 0.59 nmol/L had increased risk for incident CVD events.

LIMITATIONS

Observational study design, heterogeneity among studies, and imputation of missing data.

CONCLUSION

Men with low testosterone, high LH, or very low estradiol concentrations had increased all-cause mortality. SHBG concentration was positively associated and DHT concentration was nonlinearly associated with all-cause and CVD mortality.

PRIMARY FUNDING SOURCE

Medical Research Future Fund, Government of Western Australia, and Lawley Pharmaceuticals. (PROSPERO: CRD42019139668).

An evolutionarily conserved olfactory receptor is required for sex differences in blood pressure

Sex differences in blood pressure are well-established, with premenopausal women having lower blood pressure than men by ~10 millimeters of mercury; however, the underlying mechanisms are not fully understood. We report here that sex differences in blood pressure are absent in olfactory receptor 558 knockout (KO) mice. Olfr558 localizes to renin-positive cells in the kidney and to vascular smooth muscle cells. Female KOs exhibit increased blood pressure and increased pulse wave velocity. In contrast, male KO mice have decreased renin expression and activity, altered vascular reactivity, and decreased diastolic pressure. A rare OR51E1 (human ortholog) missense variant has a statistically significant sex interaction effect with diastolic blood pressure, increasing diastolic blood pressure in women but decreasing it in men. In summary, our findings demonstrate an evolutionarily conserved role for OLFR558/OR51E1 to mediate sex differences in blood pressure.

Major cardiovascular disease risk in men with testosterone deficiency (hypogonadism): appraisal of short, medium and long-term testosterone therapy - a narrative review

INTRODUCTION

Low testosterone (T) levels are associated with obesity, metabolic syndrome, type 2 diabetes mellitus and altered lipid profiles, thus contributing to increased cardiovascular disease risk. Hence T deficiency has a detrimental effect on men's vascular health, quality of life and increased mortality.

OBJECTIVES

This review aims to present summary of data in the contemporary clinical literature pertaining to the benefits of T therapy in clinical studies with varying durations on vascular health in men with T deficiency.

METHODS

A Medline search using PubMed and EMBASE was performed using the following key words: "testosterone deficiency," "testosterone therapy," major cardiovascular adverse events", "cardiovascular disease". Relevant studies were extracted, evaluated, and analyzed. We evaluated findings from clinical trials, observational studies and systematic reviews and meta-analyses to develop a comprehensive account of the critical role of T in maintaining vascular health.

RESULTS

Considerable evidence beginning with studies published in 1940s concomitant with findings from the utmost recent clinical studies suggests a clinical value of T therapy in maintaining vascular health and reducing cardiovascular mortality. The current scientific and clinical evidence demonstrates strong relationship between low circulating T levels and risk of cardiovascular disease and T therapy is deemed safe in men with hypogonadism when given in the physiological range with no apparent harm.

CONCLUSION

What emerges from the current clinical literature is that, irrespective of the length of study durations, testosterone therapy provides significant health benefits and reduces risk of cardiovascular disease. More important is that data from many observational and registry studies, demonstrated that longer durations of testosterone therapy were associated with greater health benefits and reduced cardiovascular risk. T therapy in men with T deficiency reduces the incidence of major adverse cardiovascular events attributed to improving overall metabolic function.

Endogenous Sex Hormone Levels and Myocardial Fibrosis in Men and Postmenopausal Women

BACKGROUND

Sex hormone (SH) imbalances have been linked to a higher risk of heart failure in both sexes. However, mechanisms that underlie this relationship remain unclear. We examined the association of baseline SH with interstitial and replacement myocardial fibrosis in the MESA (Multi-Ethnic Study of Atherosclerosis) using cardiac magnetic resonance (CMR) T1 mapping and late gadolinium enhancement (LGE).

OBJECTIVES

The purpose of this study was to assess the link between baseline sex hormone levels and myocardial fibrosis in the MESA cohort using CMR.

METHODS

A total of 2,324 participants (men and postmenopausal women [PMW]) were included in the MESA with SH measured at baseline and had underwent CMR 10 years later. All analyses were stratified by sex and age. Regression models were constructed to assess the associations of baseline SH with extracellular volume (ECV)% and native T1 time and with LGE. Higher native T1 time and ECV% are interpreted as evidence of increasing interstitial myocardial fibrosis (IMF). Given the limited number of myocardial scars present in PMW, analysis of LGE was limited to men.

RESULTS

Among older men (age ≥65 years), a 1-SD increment higher free testosterone was significantly associated with 2.45% lower ECV% and 21.5% lower native T1 time, while a 1-SD increment higher bioavailable testosterone was associated with 12.5% lower native T1 time. A 1-SD increment greater sex hormone-binding globulin level was associated with 1% higher ECV%. Among PMW of 55 to 64 years, a 1-SD increment higher total testosterone was associated with 9.5% lower native T1 time. Higher levels of estradiol in older men were independently associated with higher odds of having a myocardial scar (OR: 4.10; 95% CI: 1.35-12.40; P = 0.01).

CONCLUSIONS

Among older men, SH imbalances at initial evaluation were independently associated with CMR defined IMF and replacement fibrosis, respectively; while increasing total testosterone in middle-aged PMW was associated with lesser marker of IMF. (JACC Adv 2023;2:100320) Published by Elsevier on behalf of the American College of Cardiology Foundation.

Sex Hormone-Binding Globulin and Risk of Coronary Heart Disease in Men and Women

BACKGROUND

The role of sex hormone-binding globulin (SHBG) levels in clinical risk stratification and intervention for coronary heart disease (CHD) remains uncertain. We aimed to examine whether circulating levels of SHBG are predictive of CHD risk in men and women.

METHODS

We investigated the association between SHBG and the risk of incident CHD in 128 322 men and 135 103 women free of CHD at baseline in the prospective United Kingdom Biobank (UKB) cohort. The unconfounded associations were estimated using Mendelian randomization (MR) analysis. We further conducted a meta-analysis to integrate currently available prospective evidence. CHD events included nonfatal and fatal myocardial infarction and coronary revascularization.

RESULTS

In the UKB, during a median of 11.7 follow-up years, 10 405 men and 4512 women developed CHD. Serum levels of SHBG were monotonically associated with a decreased risk of CHD in both men (adjusted hazard ratio [HR] per log nmol/L increase in SHBG: 0.88 [0.83-0.94]) and women (HR: 0.89 [0.83-0.96]). MR-based analyses suggested causality and a dose-response relationship of SHBG with CHD risk. A cumulative meta-analysis including 216 417 men and 138 282 women from 11 studies showed that higher levels of SHBG were prospectively associated with decreased CHD risk in men comparing the highest with the lowest quartile: pooled relative risk (RR) 0.81 (0.74-0.89) and women (pooled RR: 0.86 [0.78-0.94]).

CONCLUSIONS

Higher circulating SHBG levels were directly and independently predictive of lower CHD risk in both men and women. The utility of SHBG for CHD risk stratification and prediction warrants further study.

Low endogenous estradiol levels are associated with elevated risk of cardiovascular disease mortality in young and middle-aged men in the United States

BACKGROUND AND AIMS

Evidence for the association of total estradiol (E2) with cardiovascular disease (CVD) in young men is limited. We investigated the association of total E2 or free estradiol (FE2) and CVD mortality in a nationally representative multiracial sample of young and middle-aged men in the United States.

METHODS

Data were from 954 men without CVD, cancer, diabetes and not on androgen therapy or taking anabolic steroids, who participated in the National Health and Nutrition Examination Survey (1988-1991), for whom E2 was measured, and were followed for mortality through to 2015. Fasting serum levels of E2 were measured using competitive electrochemiluminescence immunoassays. Free estradiol was estimated from the levels of estradiol, sex hormone binding globulin, and albumin. International Classification of Diseases codes were used to define CVD mortality. Cox regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

The average age of participants at baseline was 35.7 ± 11.6 years, with 11% and 6% reporting Black and Hispanic race and ethnicity, respectively. During a median follow-up of 25.2 years, 40 CVD deaths were recorded. Controlling for baseline demographic and CVD risk factors, and total testosterone levels, a 1 standard deviation decrement in log E2 (HR: 2.33, 95%CI: 1.11-5.00) or FE2 (HR: 1.89, 95%CI: 1.01-3.57) was associated with elevated risk of CVD mortality. This elevated risk was largely limited to non-Hispanic White men.

CONCLUSIONS

In this study, low levels of E2 or FE2 were associated with elevated risk of CVD mortality.

Low testosterone and high cholesterol levels in relation to all-cause, cardiovascular disease, and cancer mortality in White, Black, and Hispanic men: NHANES 1988-2015

PURPOSE

The role of testosterone (T) deficiency (T ≤ 300 ng/dL) and hypercholesterolemia (total cholesterol ≥ 240 mg/dL) in the risk of all-cause cardiovascular diseases (CVD) and cancer mortality among a nationally representative sample of non-Hispanic White (NHW), non-Hispanic Black (NHB) and Hispanic men remains poorly understood.

METHODS

Data included a full sample (NHANES 1988-1991, 1999-2004, 2011-2014) and subset sample (excluding 2011-2012, no estradiol and SHBG levels available) of 5379 and 3740 men, respectively. Participants were aged ≥ 20 y with serum T and cholesterol data (median follow-up 7.6 years). Weighted multivariable-adjusted Cox proportional hazards models were used in this study.

RESULTS

In the overall population of full and subset samples, hypercholesterolemia was inversely associated with all-cause (HR = 0.76, 95% CI, 0.63-0.91) and cancer mortality (HR = 0.56, 95% CI, 0.34-0.90). Similar findings were observed among NHW men, but higher T levels increased the risk of CVD mortality in the subset sample (T₃ vs T_1, P_trend = 0.02). Among NHB men in the full and subset samples, T deficiency increased the risk of CVD mortality, but T₃ vs. T₁ decreased it (P_trend = 0.03), and hypercholesterolemia decreased cancer mortality. Among Hispanic men in the full and subset samples, T deficiency increased, and hypercholesterolemia decreased the risk of CVD mortality.

CONCLUSION

Hypercholesterolemia was inversely associated with cancer mortality. However, higher levels of T were positively associated with CVD mortality among NHW and were inversely associated with CVD mortality among NHB and Hispanic men. Larger prospective studies are warranted to clarify the underlying relationship between T and cholesterol with mortality among racial and ethnic groups.

Associations of Serum Testosterone and Sex Hormone-Binding Globulin With Incident Cardiovascular Events in Middle-Aged to Older Men

BACKGROUND

The influence of testosterone on risk for cardiovascular events in men is uncertain. Previous observational studies of sex hormones and incident cardiovascular disease in men have reported inconsistent findings, limited by cohort sizes and different selection criteria.

OBJECTIVE

To analyze associations of serum total testosterone and sex hormone-binding globulin (SHBG) with incident cardiovascular events in men.

DESIGN

Cohort study.

SETTING

UK Biobank prospective cohort.

PARTICIPANTS

Community-dwelling men aged 40 to 69 years.

MEASUREMENTS

Testosterone and SHBG were assayed, and free testosterone was calculated. Cox proportional hazards regression was done, with outcomes of incident myocardial infarction (MI), hemorrhagic stroke (HS), ischemic stroke (IS), heart failure (HF), and major adverse cardiovascular events (MACE), adjusted for sociodemographic, lifestyle, and medical factors.

RESULTS

Of 210 700 men followed for 9 years, 8790 (4.2%) had an incident cardiovascular event. After adjustment for key variables, lower total testosterone concentrations (quintile 1 vs. quintile 5) were not associated with incident MI (fully adjusted hazard ratio [HR], 0.89 [95% CI, 0.80 to 1.00]), HS (HR, 0.94 [CI, 0.70 to 1.26]), IS (HR, 0.95 [CI, 0.82 to 1.10]), HF (HR, 1.15 [CI, 0.91 to 1.45]), or MACE (HR, 0.92 [CI, 0.84 to 1.00]). Men with lower calculated free testosterone values had a lower incidence of MACE (HR, 0.90 [CI, 0.84 to 0.97]). Lower SHBG concentrations were associated with higher incidence of MI (HR, 1.23 [CI, 1.09 to 1.38]) and lower incidence of IS (HR, 0.79 [CI, 0.67 to 0.94]) and HF (HR, 0.69 [CI, 0.54 to 0.89]), but not with HS (HR, 0.81 [CI, 0.57 to 1.14]) or MACE (HR, 1.01 [CI, 0.92 to 1.11]).

LIMITATION

Observational study; single baseline measurement of testosterone and SHBG.

CONCLUSION

Men with lower total testosterone concentrations were not at increased risk for MI, stroke, HF, or MACE. Calculated free testosterone may be associated with risk for MACE. Men with lower SHBG concentrations have higher risk for MI but lower risk for IS and HF, with causality to be determined.

PRIMARY FUNDING SOURCE

Western Australian Health Translation Network, Medical Research Future Fund, and Lawley Pharmaceuticals.

Androgen Deprivation Therapy, Hypogonadism and Cardiovascular Toxicity in Men with Advanced Prostate Cancer

Androgen deprivation therapy (ADT) is successfully used in patients with advanced prostatic cancer, but there are many concerns about its systemic side effects, especially due to advanced age and frequent comorbidities in most patients. In patients treated with ADT there are metabolic changes involving the glycaemic control and lipid metabolism, increased thrombotic risk, an increased risk of myocardial infarction, severe arrhythmia and sudden cardiac death. Still, these adverse effects can be also due to the subsequent hypogonadism. Men with heart failure or coronary artery disease have a lower level of serum testosterone than normal men of the same age, and hypogonadism is related to higher cardiovascular mortality. Many clinical studies compared the cardiovascular effects of hypogonadism post orchiectomy or radiotherapy with those of ADT but their results are controversial. However, current data suggest that more intensive treatment of cardiovascular risk factors and closer cardiological follow-up of older patients under ADT might be beneficial. Our paper is a narrative review of the literature data in this field.

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'.

Association of Genetically Predicted Serum Estradiol With Risk of Thromboembolism in Men: A Mendelian Randomization Study

CONTEXT

An association was recently reported between genetic markers related to high testosterone and increased risk of thromboembolism in men, but a possible causal role of estradiol for risk of thromboembolism in men remains unknown.

OBJECTIVE

This work aimed to determine whether endogenous estradiol has a causal role in thromboembolism in men.

METHODS

A 2-sample mendelian randomization study using gene-based genetic instruments assessed the association between endogenous estradiol genetically predicted by 22 variants in the aromatase CYP19A1 gene region and the risk of thromboembolism (5815 cases) in 170 593 unrelated men of White ancestry in the UK Biobank. The main outcome measure included thromboembolism based on self-reports, hospital episodes, and death.

RESULTS

Endogenous estradiol genetically predicted by variants in the CYP19A1 gene region was inversely associated with the risk of thromboembolism (odds ratio per SD increase in estradiol 0.74; 95% CI, 0.62-0.90). In contrast, genetic variants in the JMJD1C gene, used as a predictor of high endogenous testosterone, were associated with an increased risk of thromboembolism (odds ratio per SD increase in testosterone 1.39; 95% CI, 1.12-1.72). Subsequent explorative analyses evaluating potential repercussions of thromboembolism revealed that endogenous estradiol genetically predicted by variants in the CYP19A1 gene region was inversely associated with the risk of ischemic stroke (0.68; 95% CI, 0.49-0.95) but not myocardial infarction (0.97; 95% CI, 0.84-1.13).

CONCLUSION

Genetically predicted estradiol was inversely associated with the risk of thromboembolism and ischemic stroke in men. The ratio between testosterone and estradiol, determined by CYP19A1 activity, may contribute to the overall impact of sex steroids on thromboembolism in men.

Both comorbidity burden and low testosterone can explain symptoms and signs of testosterone deficiency in men consulting for sexual dysfunction

Low testosterone (T) is frequent in men with chronic illnesses. The clinical features of T deficiency (TD) overlap with those of chronic diseases. The aim of this study is to evaluate the relative contribution of chronic disease score (CDS) and low T to the presence of TD symptoms. A consecutive series of 3862 men (aged 52.1 ± 13.1 years) consulting for sexual dysfunction were studied. Several clinical and biochemical parameters were collected, including the structured interview, ANDROTEST, for the assessment of TD symptoms. Penile color Doppler ultrasound (PCDU) was also performed. Based on the medications taken, the CDS was calculated. For a subset of 1687 men, information on mortality was collected (follow-up of 4.3 ± 2.6 years). Higher CDS was associated with lower free and total T (TT) as well as with higher ANDROTEST score. When introducing CDS and TT in multivariable models adjusted for age, severe erectile dysfunction and impaired morning erections were associated with both CDS (odds ratio and 95% confidence interaval, OR [95% CI] = 1.25 [1.13; 1.37] and 1.38 [1.29; 1.48], respectively) and low TT (OR [95% CI] = 1.11 [1.00; 1.23] and 1.13 [1.06; 1.21], respectively). Similar results were obtained for PCDU parameters. Hypoactive sexual desire was associated with low TT (OR [95% CI] = 1.21 [1.13; 1.30]), whereas it was inversely related with CDS (OR [95% CI] = 0.91 [0.84; 0.97]). When considering mortality for major cardiovascular events, TT <8 nmol l⁻¹, but not CDS, was a significant predictor (hazard ratio [95% CI] = 5.57 [1.51; 20.63]). Chronic illnesses are associated with an overt TD. Both chronic diseases and low T can be involved in determining symptoms present in subjects complaining for sexual dysfunction. This should be considered in the diagnostic workup for TD.

Serum Testosterone is Inversely and Sex Hormone-binding Globulin is Directly Associated with All-cause Mortality in Men

CONTEXT

Serum testosterone concentrations decline with age, while serum sex hormone-binding globulin (SHBG) concentrations increase.

OBJECTIVE

To analyze associations of baseline serum testosterone and SHBG concentrations, and calculated free testosterone (cFT) values, with all-cause and cause-specific mortality in men.

DESIGN, SETTING, AND PARTICIPANTS

The UK Biobank prospective cohort study of community-dwelling men aged 40-69 years old, followed for 11 years.

MAIN OUTCOME MEASURES

All-cause, atherosclerotic cardiovascular disease (CVD) and cancer-related mortality. Cox proportional hazards regression was performed, adjusting for age, waist circumference, medical conditions, and other covariates. Models for testosterone included SHBG and vice versa.

RESULTS

In a complete case analysis of 149 436 men with 10 053 deaths (1925 CVD and 4927 cancer-related), men with lower testosterone had a higher mortality rate from any cause (lowest vs highest quintile, Q1 vs Q5, fully-adjusted hazard ratio [HR] = 1.14, 95% confidence interval [CI] = 1.06-1.22, overall trend P < 0.001), and cancer (HR = 1.20, CI = 1.09-1.33, P < 0.001), with no association for CVD deaths. Similar results were seen for cFT. Men with lower SHBG had a lower mortality rate from any cause (Q1 vs Q5, HR = 0.68, CI = 0.63-0.73, P < 0.001), CVD (HR = 0.70, CI = 0.59-0.83, P < 0.001), and cancer (HR = 0.80, CI = 0.72-0.89, P < 0.001). A multiply imputed dataset (N = 208 425, 15 914 deaths, 3128 CVD-related and 7468 cancer-related) and analysis excluding deaths within the first 2 years (9261, 1734, and 4534 events) yielded similar results.

CONCLUSIONS

Lower serum testosterone is independently associated with higher all-cause and cancer-related, but not CVD-related, mortality in middle-aged to older men. Lower SHBG is independently associated with lower all-cause, CVD-related, and cancer-related mortality. Confirmation and determination of causality requires mechanistic studies and prospective trials.

Worse progression of COVID-19 in men: Is testosterone a key factor?

BACKGROUND

The novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) disease 2019 (COVID-19) seems to have a worse clinical course among infected men compared with women, thus highlighting concerns about gender predisposition to serious prognosis. Therefore, androgens, particularly testosterone (T), could be suspected as playing a critical role in driving this excess of risk. However, gonadal function in critically ill men is actually unknown, mainly because serum T concentration is not routinely measured in clinical practice, even more in this clinical context.

OBJECTIVE

To overview on possible mechanisms by which serum T levels could affect the progression of COVID-19 in men.

METHODS

Authors searched PubMed/MEDLINE, Web of Science, EMBASE, Cochrane Library, Google, and institutional websites for medical subject headings terms and free text words referred to "SARS-CoV-2," "COVID-19," "testosterone," "male hypogonadism," "gender" "immune system," "obesity," "thrombosis" until May 19th 2020.

RESULTS

T, co-regulating the expression of angiotensin-converting enzyme 2 and transmembrane protease serine 2 in host cells, may facilitate SARS-CoV-2 internalization. Instead, low serum T levels may predispose to endothelial dysfunction, thrombosis and defective immune response, leading to both impaired viral clearance and systemic inflammation. Obesity, one of the leading causes of severe prognosis in infected patients, is strictly associated with functional hypogonadism, and may consistently strengthen the aforementioned alterations, ultimately predisposing to serious respiratory and systemic consequences.

DISCUSSION AND CONCLUSION

T in comparison to estrogen may predispose men to a widespread COVID-19 infection. Low serum levels of T, which should be supposed to characterize the hormonal milieu in seriously ill individuals, may predispose men, especially elderly men, to poor prognosis or death. Further studies are needed to confirm these pathophysiological assumptions and to promptly identify adequate therapeutic strategies.

Oral Contraceptives and Venous Thromboembolism: Focus on Testing that May Enable Prediction and Assessment of the Risk

Combined oral contraceptives (COCs) induce several changes in the levels of coagulation factors. The levels of procoagulant factors are often increased, while levels of anticoagulant factors are decreased. Fibrinolysis is also affected, even if the effect seems to be more counterbalanced by opposite regulation of profibrinolytic and antifibrinolytic factors. These effects on hemostasis are more pronounced with third- or fourth-generation COC compared with second-generation COC. Venous thromboembolism (VTE) risk increases when multiple risk factors, including genetic and environmental, are present simultaneously. COC use causes changes in coagulation that modify the prothrombotic state induced by preexisting hemostatic alterations in a supra-additive manner. Therefore, testing appears to be of importance not only before implementing COC but also to monitor any potential thrombogenicity induced by COC therapy. Inherited genetic factors, such as factor V Leiden, G20210A prothrombin mutation, antithrombin, protein C or protein S deficiencies, non-O blood group, as well as CYP2C9*2 and the rs4379368 mutations, have all been identified as genetic predictive risk factors of VTE in women. Nevertheless, the screening of these genetic biomarkers is not capable of assessing the phenotypic expression of the risk. This review will focus on the different options for screening the thrombogenic status in this population. Specific attention will be given to the endogenous thrombin potential-based activated protein C resistance, a test aiming at assessing the thrombogenicity induced by hormonal therapies and inherited or acquired thrombophilia.

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.

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.

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.

Testosterone and its metabolites: differential associations with cardiovascular and cerebrovascular events in men

As men grow older, circulating testosterone declines while the incidence of cardiovascular disease increases. Thus, the role of sex hormones as biomarkers, and possibly contributing factors to clinical manifestations of cardiovascular disease in the increasing demographic of aging men, has attracted considerable interest. This review focuses on observational studies of endogenous androgens, namely circulating testosterone and dihydrotestosterone, which have examined their associations with cardiovascular events such as myocardial infarction and stroke. Studies which have examined the associations of endogenous estrogens, namely circulating estradiol, with these outcomes are also discussed. In large prospective cohort studies of predominantly middle-aged and older men, lower circulating testosterone consistently predicts higher incidence of cardiovascular events. Of note, both lower circulating testosterone and lower dihydrotestosterone are associated with higher incidence of stroke. These associations are less apparent when myocardial infarction is considered as the outcome. Results for estradiol are inconsistent. Lower circulating testosterone has been shown to predict higher cardiovascular disease-related mortality, as has lower circulating dihydrotestosterone. It is possible that the relationship of circulating androgens to cardiovascular events or mortality outcomes may be U-shaped rather than linear, with an optimal range defining men at lowest risk. Epidemiological studies are observational in nature and do not prove causality. Associations observed in studies of endogenous androgens need not necessarily translate into similar effects of exogenous androgens. Rigorous randomized controlled trials are needed to clarify the effects of testosterone treatment on cardiovascular risk in men.

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.

Benefits and risks of testosterone therapy in older men

Adult-onset hypogonadism is used to define androgen deficiency and its associated symptoms commonly occurring in middle-aged and elderly men, who are unable to mount an adequate compensatory gonadotropin response but may also have an element of testicular failure. It often occurs in relation with chronic metabolic conditions such as diabetes and the metabolic syndrome. There is a growing demand from elderly men for testosterone therapy. The physician should therefore be well-informed so as the patient can make an informed decision. Indeed, testosterone therapy in older men has been a matter of debate, especially with regard to its impact on cardiovascular events and mortality. Not all studies have reported consistent results regarding its effect on diabetes, obesity and the metabolic syndrome. In contrast, it appears to improve sexual, physical function and bone density and it does not appear to increase the risk of prostate cancer; however, it increases hematocrit and hemoglobin levels. Therefore, testosterone therapy might provide significant beneficial effects in older symptomatic hypogonadal men; treatment should be individualized, and comorbidities addressed. Further research is required into its long-term effects.

Testosterone, sex hormone-binding globulin and risk of cardiovascular events: A report from the Outcome Reduction with an Initial Glargine Intervention trial

Aims: Testosterone and its binding protein sex hormone-binding globulin have been associated with cardiovascular disease and dysglycaemia. However, information on the prognostic implication in patients at high cardiovascular risk with dysglycaemia is inconsistent. The study objective was to determine whether testosterone and/or sex hormone-binding globulin predict cardiovascular events or death in dysglycaemic patients.

Methods: Dysglycaemic males at high cardiovascular risk ( n = 5553) who participated in the Outcome Reduction with an Initial Glargine Intervention (ORIGIN) trial and provided baseline blood samples were studied. Testosterone and sex hormone-binding globulin were measured at baseline and used to estimate free testosterone. Low levels of total and free testosterone were defined as ≤300 ng/dl and ≤7 ng/dl, respectively. Patients were followed for six years for cardiovascular events (defined as the composite of cardiovascular death, non-fatal myocardial infarction or stroke) and all-cause mortality.

Results: The mean total and free testosterone levels were 416.6 ng/dl and 8.4 ng/dl, and low levels were present in 13% and 37% of the patients. The median sex hormone-binding globulin level was 35 nmol/l. In Cox regression models adjusted for age, previous diseases and pharmacological treatment, neither total nor free testosterone predicted cardiovascular events. However, a one-standard-deviation increase in sex hormone-binding globulin predicted both cardiovascular events (hazard ratio 1.07; 95% confidence interval 1.00–1.14; p = 0.03) and all-cause mortality (hazard ratio 1.13; 95% confidence interval 1.06–1.21; p < 0.01).

Conclusion: Sex hormone-binding globulin, but not total testosterone, predicts cardiovascular disease and all-cause mortality in dysglycaemic males at high cardiovascular risk.

Obesity, Male Reproductive Function and Bariatric Surgery

Overweight and obesity are associated with several chronic complications, such as type 2 diabetes, arterial hypertension and atherosclerotic cardiovascular diseases, with relevant consequences for patients and public health systems. Reproductive function abnormalities, such as obesity-related secondary hypogonadism, erectile dysfunction and infertility, represent other abnormalities negatively affecting the quality of life of men suffering from obesity but, despite their high prevalence, these are often understated because of a general lack of awareness in clinical practice. Obesity and gonadal function are closely related, with obesity being associated with hypogonadism that is reversed by body weight reduction thus ameliorating reproductive and sexual health. Clinical studies specifically evaluating the impact of non-surgical weight loss on testosterone levels sometimes showed conflicting results, whereas extensive literature has demonstrated that weight loss after bariatric surgery is correlated with an increase in testosterone levels greater than that obtained with only lifestyle interventions, suggesting the role of surgery also for the treatment of hypogonadism in obese male. However, studies concerning the consequences of bariatric surgery on overall reproductive function in the male, including also sexual activity and fertility, are limited and data regarding long-term effects are lacking. Here we present a brief review summarizing the evidence regarding the interplay between obesity and reproductive abnormalities in the obese male, together with the role of bariatric surgery for the treatment of these complications, describing both the positive effects and the limitations of this procedure.

Dynamics of testosterone levels in patients with newly detected glucose abnormalities and acute myocardial infarction

OBJECTIVE

Low testosterone has been associated with increased cardiovascular risk and glucose abnormalities. This study explored the prevalence of low testosterone, dynamics over time and prognostic implications in acute myocardial infarction patients with or without glucose abnormalities.

METHODS

Male acute myocardial infarction patients (n = 123) and healthy controls (n = 124) were categorised as having normal or abnormal glucose tolerance (impaired glucose tolerance or diabetes) by oral glucose tolerance testing. Testosterone was measured at hospital admission, discharge, 3 and 12 months thereafter in patients. Patients and controls were followed for 11 years for major cardiovascular events (cardiovascular death/acute myocardial infarction/stroke/severe heart failure).

RESULTS

At hospital admission, more patients had low testosterone (⩽300 ng/dl) and lower median levels than controls (64 vs 28%; p < 0.001 and 243 vs 380 ng/dl; p < 0.01). At the subsequent time points, testosterone had increased to 311, 345 and 357 ng/dl. Patients with abnormal glucose tolerance had the highest prevalence (75%) of low levels. In adjusted Cox regression models, neither total nor free testosterone predicted major cardiovascular events.

CONCLUSION

Low testosterone levels were common in male acute myocardial infarction patients in the acute phase, especially in the presence of abnormal glucose tolerance, but increased over time indicating that testosterone measured in close proximity to acute myocardial infarction should be interpreted with caution.

Oestradiol level, oestrogen receptors, and mortality in elderly men: The three-city cohort study

CONTEXT

Although endogenous oestradiol, generally considered as the female hormone, has been little investigated in men, it could play a role in men's health, mortality in particular. The influence of oestrogen receptors (ER) genetic polymorphisms on this relationship has never been studied.

DESIGN AND PARTICIPANTS

The Three-City cohort study included (1999-2001) 3650 men ≥65 years who were followed for mortality over 12 years. At baseline, total oestradiol (tE2) was measured and ER genotyped in a random subsample of 472 men without hormonal treatment. Free oestradiol (fE2) was estimated using Vermeulen and Södergard algorithms.

MAIN OUTCOME

Mortality data were obtained from death certificates. We used inverse probability weighted Cox models to examine the association of oestradiol with all-cause and cause-specific mortality and its interaction with ER genetic polymorphisms.

RESULTS

A total of 183 men died over the follow-up (cardiovascular disease (CVD), n = 44; cancer, n = 57; other causes, n = 82). After adjustment, there was a quadratic relationship of all-cause mortality with tE2 and fE2 (P-quadratic = 0.04 and 0.05, respectively), with higher mortality for the top and bottom tertiles compared to the middle one. These associations were stronger for CVD mortality (P-quadratic = 0.01 and 0.02 for tE2 and fE2, respectively) and disappeared for cancer mortality. There was no evidence of an interaction of oestradiol with any ER polymorphisms on all-cause mortality.

CONCLUSION

In elderly men, we showed a nonlinear association of tE2 and fE2 with all-cause mortality. These quadratic relationships were stronger for CVD mortality and did not exist for cancer mortality. ER genetic polymorphisms did not modify this association.

Low testosterone in ApoE/LDL receptor double-knockout mice is associated with rarefied testicular capillaries together with fewer and smaller Leydig cells

The testis as a site for atherosclerotic changes has so far attracted little attention. We used the apolipoprotein E (ApoE)/low density lipoprotein (LDL) receptor deficient mouse model (KO) for atherosclerosis (20, 40, 60 and 87-week-old) to investigate whether Leydig cells or the capillary network are responsible for reduced serum testosterone levels previously observed in extreme ages of this model. In KO mice, overall testosterone levels were reduced whereas the adrenal gland-specific corticosterone was increased excluding a general defect of steroid hormone production. In addition to micro-CT investigations for bigger vessels, stereology revealed a reduction of capillary length, volume and surface area suggesting capillary rarefaction as a factor for diminished testosterone. Stereological analyses of interstitial cells demonstrated significantly reduced Leydig cell numbers and size. These structural changes in the testis occurred on an inflammatory background revealed by qPCR. Reduced litter size of the KO mice suggests hypo- or infertility as a consequence of the testicular defects. Our data suggest reduced testosterone levels in this atherosclerosis model might be explained by both, rarefication of the capillary network and reduced Leydig cell number and size. Thus, this study calls for specific treatment of male infertility induced by microvascular damage through hypercholesterolemia and atherosclerosis.

Testosterone and All-Cause Mortality in Older Men: The Role of Metabolic Syndrome

Previous studies have shown controversial results about the role of testosterone in all-cause mortality in elderly men. We hypothesized that metabolic syndrome (MetS) could partly explain this discrepancy. We therefore examined the association of all-cause mortality with total and bioavailable testosterone, taking into account the MetS. We used data from the Three-City Cohort (3C) study with 12-year follow-up. The 3C study included 3650 men aged >65 years in three French cities. Hormone was measured in a random subsample of 444 men, and MetS was determined as stated by the International Diabetes Federation criteria. We used inverse-probability-weighted Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs). Of 444 men included in the analysis, 106 (23.9%) had MetS at baseline, and 166 died over the follow-up. There was a significant interaction between testosterone level and MetS for all-cause mortality (P = 0.002 and P = 0.008 for total and bioavailable testosterone, respectively). Among men with MetS, a decrease in one standard deviation of testosterone was associated with higher mortality risk [HR 1.78 (95% CI 1.13 to 2.78) and HR 1.83 (95% CI 1.17 to 2.86) for total and bioavailable testosterone, respectively]. By contrast, there was no association of testosterone with mortality risk among men without MetS. Our results suggest that MetS modifies the association between testosterone and mortality in older men. If confirmed, these findings could contribute to improve risk stratification and better manage the health of older men.

Association of sex hormones with physical, laboratory, and imaging markers of anthropometry in men and women from the general population

OBJECTIVES

The aim of this study was to evaluate the association of sex hormones with anthropometry in a large population-based cohort, with liquid chromatography-mass spectrometry (LCMS)-based sex hormone measurements and imaging markers.

STUDY DESIGN/MAIN OUTCOME MEASURES

Cross-sectional data from 957 men and women from the population-based Study of Health in Pomerania (SHIP) were used. Associations of a comprehensive panel of LCMS-measured sex hormones with anthropometric parameters, laboratory, and imaging markers were analyzed in multivariable regression models for the full sample and stratified by sex. Sex hormone measures included total testosterone (TT), free testosterone (fT), estrone and estradiol, androstenedione (ASD), dehydroepiandrosterone sulfate (DHEAS), and sex hormone-binding globulin (SHBG). Domains of anthropometry included physical measures (body-mass-index (BMI), waist circumference, waist-to-height-ratio, waist-to-hip-ratio, and hip circumference), laboratory measures of adipokines (leptin and vaspin), and magnet resonance imaging-based measures (visceral and subcutaneous adipose tissue).

RESULTS

In men, inverse associations between all considered anthropometric parameters with TT were found: BMI (β-coefficient, standard error (SE): -0.159, 0.037), waist-circumference (β-coefficient, SE: -0.892, 0.292), subcutaneous adipose tissue (β-coefficient, SE: -0.156, 0.023), and leptin (β-coefficient, SE: -0.046, 0.009). In women TT (β-coefficient, SE: 1.356, 0.615) and estrone (β-coefficient, SE: 0.014, 0.005) were positively associated with BMI. In analyses of variance, BMI and leptin were inversely associated with TT, ASD, and DHEAS in men, but positively associated with estrone. In women, BMI and leptin were positively associated with all sex hormones.

CONCLUSION

The present population-based study confirmed and extended previously reported sex-specific associations between sex hormones and various anthropometric markers of overweight and obesity.

Individual testosterone decline and future mortality risk in men

OBJECTIVE

Male aging is characterized by a decline in testosterone (TS) levels with a substantial variability between subjects. However, it is unclear whether differences in age-related changes in TS are associated with general health. We investigated associations between mortality and intra-individual changes in serum levels of total TS, SHBG, free TS and LH during a ten-year period with up to 18 years of registry follow-up.

DESIGN

1167 men aged 30-60 years participating in the Danish Monitoring Trends and Determinants of Cardiovascular Disease (MONICA1) study and who had a follow-up examination ten years later (MONICA10) were included. From MONICA10, the men were followed up to 18 years (mean: 15.2 years) based on the information from national mortality registries via their unique personal ID numbers.

METHODS

Cox proportional hazard models were used to investigate the association between intra-individual hormone changes and all-cause, CVD and cancer mortalities.

RESULTS

A total of 421 men (36.1%) died during the follow-up period. Men with most pronounced decline in total TS (<10th percentile) had a higher all-cause mortality risk compared to men within the 10th to 90th percentile (hazard ratio (HR): 1.60; 95% confidence interval (CI): 1.08-2.36). No consistent associations were seen in cause-specific mortality analyses.

CONCLUSION

Our study showed that higher mortality rates were seen among the men who had the most pronounced age-related decline in TS, independent of their baseline TS levels.

Aging and sex hormones in males

Several large cohort studies have disclosed the trajectories of sex steroids changes overtime in men and their clinical significance. In men the slow, physiological decline of serum testosterone (T) with advancing age overlaps with the clinical condition of overt, pathological hypogonadism. In addition, the increasing number of comorbidities, together with the high prevalence of chronic diseases, all further contribute to the decrease of serum T concentrations in the aging male. For all these reasons both the diagnosis of late-onset hypogonadism (LOH) in men and the decision about starting or not T replacement treatment remain challenging. At present, the biochemical finding of T deficiency alone is not sufficient for diagnosing hypogonadism in older men. Coupling hypogonadal symptoms with documented low serum T represents the best strategy to refine the diagnosis of hypogonadism in older men and to avoid unnecessary treatments.

Dose-response effects of sex hormone concentrations on body composition and adipokines in medically castrated healthy men administered graded doses of testosterone gel

OBJECTIVE

Serum sex steroid concentrations may alter body composition and glucose homoeostasis in men in a dose-response manner. We evaluated these end-points in healthy men rendered medically castrate through use of a gonadotrophin-releasing hormone antagonist (acyline) with incremental doses of exogenous testosterone (T) gel.

DESIGN

Subjects (n=6-9 per group) were randomly assigned to injections of acyline every 2 weeks plus transdermal T gel (1.25 g, 2.5 g, 5.0 g, 10 g or 15 g) daily or double placebo (injections and gel) for 12 weeks.

PATIENTS

Healthy men, ages 25-55 years, with normal serum total T concentrations.

MEASUREMENTS

Serum T, dihydrotestosterone (DHT) and oestradiol (E2) were measured at baseline and every 2 weeks. Body composition was analysed by dual-energy X-ray absorptiometry at baseline and week 12. Fasting serum adiponectin, leptin, glucose and insulin concentrations were measured at baseline and week 10.

RESULTS

Forty-eight men completed the study. A significant treatment effect was observed for change in lean mass (ANOVAP=.01) but not fat mass (P=.14). Lean mass increased in the 15 g T group relative to all lower dose groups, except the 10 g T group. When all subjects were analysed together, changes in lean mass correlated directly and changes in fat mass correlated inversely with serum T, E2 and DHT. No changes were noted in serum glucose, insulin or adipokine levels.

CONCLUSIONS

In healthy men, higher serum concentrations of T, DHT and E2 were associated with greater increases in lean mass and decreases in fat mass but not with changes in serum glucose, insulin or adipokines.

The Graham Jackson Memorial Lecture ISSM 2016-"The Man Who Knew Too Much": Time to Recognize Erectile Dysfunction and Low Testosterone as Independent Risk Factors for Cardiovascular Disease

INTRODUCTION

Graham Jackson introduced the concept that erectile dysfunction (ED) is a marker for undiagnosed cardiovascular (CV) disease and future events. In the Princeton 3 guidelines, he recognized the important impact of testosterone deficiency (TD) on all-cause and CV mortality. Recent evidence suggests that testosterone therapy to target levels and for sufficient duration decreases CV events. Unfortunately, this had a modest impact on CV disease management because ED is not incorporated into current risk calculators. This report is based on the Graham Jackson Memorial Lecture presented at the International Society for Sexual Medicine (ISSM) in Beijing in 2016.

AIM

To examine recent evidence as to whether ED should be upgraded to a risk factor, especially with the high predictive value in younger men, and to develop a case for TD to be considered an independent risk factor based on a large number of long-term studies during the past 5 years.

METHODS

A Medline search was undertaken to include articles on ED and TD and related terms from 1998 to 2016 during the preparation of ISSM guidelines on ED and TD.

MAIN OUTCOME MEASURES

A rational justification for ED and low testosterone to be considered risk factors for CV disease and be included in risk calculators.

RESULTS

The evidence for inclusion of ED and TD might be stronger than for accepted risk factors and have the advantages of being easily assessed, quantitative, symptomatic, and clinically relevant, especially in younger men. Because important studies are often published in endocrine, sexual medicine, urology, and cardiology journals, a multidisciplinary approach is needed.

CONCLUSION

There is strong evidence that ED and low testosterone might be of more practical relevance to programs that decrease CV risk than some current recognized risk factors. Hackett G. The Graham Jackson Memorial Lecture ISSM 2016-"The Man Who Knew Too Much": Time to Recognize Erectile Dysfunction and Low Testosterone as Independent Risk Factors for Cardiovascular Disease. Sex Med Rev 2017;5:256-265.

An independent validation study of three single nucleotide polymorphisms at the sex hormone-binding globulin locus for testosterone levels identified by genome-wide association studies

Study question

Are the single nucleotide polymorphisms (SNPs) rs2075230, rs6259 and rs727428 at the sex hormone-binding globulin (SHBG) locus, which were identified by genome-wide association studies (GWASs) for testosterone levels, associated with testosterone levels in Japanese men?

Summary answer

The SNP rs2075230, but not rs6259 and rs727428, is significantly associated with testosterone levels in Japanese men.

What is already known

Previous GWASs have revealed that rs2075230 is associated with serum testosterone levels in 3495 Chinese men and rs6259 and rs727428 are associated with serum testosterone levels in 3225 men of European ancestry.

Study design, size, and duration

This is an independent validation study of 1687 Japanese men (901 in Cohort 1 and 786 in Cohort 2).

Participants/materials, setting and method

Cohort 1 (20.7 ± 1.7 years old, mean ± SD) and Cohort 2 (31.2 ± 4.8 years) included samples obtained from university students and partners of pregnant women, respectively. The three SNPs were genotyped using either TaqMan probes or restriction fragment length polymorphism PCR. Blood samples were drawn from the cubital vein of the study participants in the morning, and total testosterone and SHBG levels were measured using a time-resolved immunofluorometric assay. Association between each SNP and testosterone levels was evaluated by meta-analysis of the two Japanese male cohorts.

Main results and the role of chance

The age of the two cohorts was significantly different (P < 0.0001). We found that rs2075230 was significantly associated with serum testosterone levels (β_STD = 0.15, P = 7.2 × 10⁻⁶); however, rs6259 and rs727428 were not (β_STD = 0.17, P = 0.071; β_STD = 0.082, P = 0.017, respectively), after adjusting for multiple testing in a combined analysis of two Japanese male cohorts. Moreover, rs2075230, rs6259 and rs727428 were significantly associated with high SHBG levels (β_STD = 0.22, P = 3.4 × 10⁻¹²; β_STD = 0.23, P = 6.5 × 10⁻⁶ and β_STD = 0.21, P = 3.4 × 10⁻¹⁰, respectively).

Large scale data

Not applicable.

Limitations, reasons for caution

This study had differences in the age and background parameters of participants compared to those observed in previous GWASs. In addition, the average age of participants in the two cohorts in our study also differed from one another. Therefore, the average testosterone levels, which decrease with age, between studies or the two cohorts were different.

Wider implications of the findings

The three SNPs have a considerable effect on SHBG levels and hence may indirectly affect testosterone levels.

Study funding/competing interests

This study was supported partly by the Ministry of Health and Welfare of Japan (1013201) (to T.I.), Grant-in-Aids for Scientific Research (C) (26462461) (to Y.S.) and (23510242) (to A.Ta.) from the Japan Society for the Promotion of Science, the European Union (BMH4-CT96-0314) (to T.I.) and the Takeda Science Foundation (to A.Ta.). There are no conflicts of interest to declare.

Low Levels of Sex Hormone-Binding Globulin Constitute an Independent Risk Factor for Arterial Stiffness in Korean Women

The association between sex hormone-binding globulin (SHBG) and arterial stiffness in women is not conclusive. In addition, obesity might also be involved in the relationship between SHBG and atherosclerosis. The aim of this study was to determine the relationship between SHBG and arterial stiffness in association with central obesity in women. This cross-sectional study included 381 women who participated in the health checkup programs in one hospital. The brachial-ankle pulse wave velocity (baPWV) was measured as a marker for arterial stiffness. A negative correlation was observed between SHBG levels and baPWV (rho = -0.281). The relationship was significant even after adjusting for potential confounders (beta = -0.087 in fully adjusted model). After considering the interaction between central obesity and SHBG levels, the significant association was evident only in obese women (P for interaction = 0.025). Adjustment for a 10-year atherosclerotic cardiovascular disease (ASCVD) risk scores, instead of each cardiovascular risk factor individually, did not affect the significance of the relationship between SHBG levels and baPWV. Serum levels of SHBG were negatively associated with arterial stiffness independent of cardiovascular risk factors or 10-year ASCVD risk scores in Korean women. The relationship may be potentiated by central obesity.

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.

Testosterone replacement therapy and the heart: friend, foe or bystander?

The role of testosterone therapy (TTh) in cardiovascular disease (CVD) outcomes is still controversial, and it seems will remain inconclusive for the moment. An extensive body of literature has investigated the association of endogenous testosterone and use of TTh with CVD events including several meta-analyses. In some instances, a number of studies reported beneficial effects of TTh on CVD events and in other instances the body of literature reported detrimental effects or no effects at all. Yet, no review article has scrutinized this body of literature using the magnitude of associations and statistical significance reported from this relationship. We critically reviewed the previous and emerging body of literature that investigated the association of endogenous testosterone and use of TTh with CVD events (only fatal and nonfatal). These studies were divided into three groups, “beneficial (friendly use)”, “detrimental (foe)” and “no effects at all (bystander)”, based on their magnitude of associations and statistical significance from original research studies and meta-analyses of epidemiological studies and of randomized controlled trials (RCT’s). In this review article, the studies reporting a significant association of high levels of testosterone with a reduced risk of CVD events in original prospective studies and meta-analyses of cross-sectional and prospective studies seems to be more consistent. However, the number of meta-analyses of RCT’s does not provide a clear picture after we divided it into the beneficial, detrimental or no effects all groups using their magnitudes of association and statistical significance. From this review, we suggest that we need a study or number of studies that have the adequate power, epidemiological, and clinical data to provide a definitive conclusion on whether the effect of TTh on the natural history of CVD is real or not.

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.

Neutral associations of testosterone, dihydrotestosterone and estradiol with fatal and non-fatal cardiovascular events, and mortality in men aged 17-97 years

CONTEXT

Lower testosterone (T) is associated with poorer health outcomes in older men, however, the relationship between T, dihydrotestosterone (DHT) and estradiol (E2) with cardiovascular disease (CVD) in younger to middle-aged men remains unclear.

OBJECTIVES

We assessed associations between endogenous sex hormones with mortality (all-cause and CVD) and CVD events, in a cohort of men aged 17-97 years.

PARTICIPANTS AND METHODS

Sex hormones were assayed using mass spectrometry in 2143 men from the 1994/5 Busselton Health Survey. Outcomes to December 2010 were analysed.

RESULTS

Of the 1804 men included in the analysis, mean age was 50·3 ± 16·8 years and 68·9% of men were aged <60. Mean follow-up period was 14·9 years. There were 319 deaths, 141 CVD deaths and 399 CVD events. Compared to the full cohort, men who died had lower baseline T (12·0 ± 4·4 vs 13·6 ± 4·9 nmol/l), free T (181·9 ± 52·9 vs 218·3 ± 63·8 pmol/l) and DHT (1·65 ± 0·64 vs 1·70 ± 0·72 nmol/l), but higher E2 (64·0 ± 32 vs 60·1 ± 30·2 pmol/l). After adjustment for risk factors, T was not associated with mortality (adjusted HR = 0·90, 95% CI 0·79-1·04; P = 0·164 for every increase in 1 SD of T), CVD deaths (adjusted HR = 1·04, 95% CI 0·84-1·29; P = 0·708) or CVD events (adjusted HR = 1·03, 95% CI 0·92-1·15, P = 0·661). No associations were found for free T, DHT or E2. Results were similar for men older and younger than 60 years.

CONCLUSIONS

In predominantly middle-aged men, T, DHT and E2 do not influence mortality or CVD outcomes. This neutral association of hormones with CVD contrasts with prior studies of older men.

Stable Intraprostatic Dihydrotestosterone in Healthy Medically Castrate Men Treated With Exogenous Testosterone

CONTEXT

Concern exists that T replacement therapy (TRT) might increase the risk of prostate disease. There are limited data regarding the impact of TRT on prostate androgen concentrations.

OBJECTIVE

Determine the dose-dependent effects of exogenous T administration on intraprostatic androgen concentrations.

DESIGN

Twelve-week, double-blinded, randomized, placebo-controlled trial.

SETTING

Academic medical center.

PARTICIPANTS

Sixty-two healthy eugonadal men, aged 25-55 years.

INTERVENTIONS

Subjects were randomly assigned to receive injections of acyline, a GnRH antagonist (used to achieve medical castration), every 2 weeks plus transdermal T gel (1.25 g, 2.5 g, 5.0 g, 10 g, or 15 g daily), or placebo injections and transdermal gel for 12 weeks.

MAIN OUTCOMES

Serum T and dihydrotestosterone (DHT) were measured at baseline and every 2 weeks during treatment. Intraprostatic T and DHT concentrations were assessed from tissue obtained through ultrasound-guided prostate needle biopsies at week 12. Androgens were quantified by liquid chromatography-tandem mass spectrometry.

RESULTS

51 men completed the study and were included in the analysis. There were no significant adverse events. Exogenous T resulted in a dose-dependent increase in serum T and DHT concentrations (190-770 and 60-180 ng/dL, respectively). Although intraprostatic T differed among dose groups (P = .01), intraprostatic DHT was comparable regardless of T dose (P = .11) and was 10- to 20-fold greater than intraprostatic T.

CONCLUSIONS

In healthy, medically castrate men receiving exogenous T, the total intraprostatic androgen concentration (predominantly DHT) remained stable across serum T concentrations within the physiological range. These findings further our knowledge of the relationship between serum and intraprostatic androgens and suggest that physiological serum T achieved by TRT is unlikely to alter the prostate hormonal milieu.

Testosterone deficiency and cardiovascular mortality

New concerns have been raised regarding cardiovascular (CV) risks with testosterone (T) therapy (TTh). These concerns are based primarily on two widely reported retrospective studies. However, methodological flaws and data errors invalidate both studies as credible evidence of risk. One showed reduced adverse events by half in T-treated men but reversed this result using an unproven statistical approach. The authors subsequently acknowledged serious data errors including nearly 10% contamination of the dataset by women. The second study mistakenly used the rate of T prescriptions written by healthcare providers to men with recent myocardial infarction (MI) as a proxy for the naturally occurring rate of MI. Numerous studies suggest T is beneficial, including decreased mortality in association with TTh, reduced MI rate with TTh in men with the greatest MI risk prognosis, and reduced CV and overall mortality with higher serum levels of endogenous T. Randomized controlled trials have demonstrated benefits of TTh in men with coronary artery disease and congestive heart failure. Improvement in CV risk factors such as fat mass and glycemic control have been repeatedly demonstrated in T-deficient men treated with T. The current evidence does not support the belief that TTh is associated with increased CV risk or CV mortality. On the contrary, a wealth of evidence accumulated over several decades suggests that low serum T levels are associated with increased risk and that higher endogenous T, as well as TTh itself, appear to be beneficial for CV mortality and risk.

Controversies in testosterone replacement therapy: testosterone and cardiovascular disease

The role of testosterone in the cardiovascular (CV) health of men is controversial. Data suggest that both the condition and treatment of clinical hypogonadism is associated with decreased CV mortality; however, two recent studies suggest that hypogonadal subjects treated with testosterone replacement therapy have a higher incidence of new CV events. There has been increased media attention concerning the risk of CV disease in men treated with testosterone. Until date, there are no long-term prospective studies to determine safety. Literature spanning over the past 30 years has suggested that not only is there a possible increased CV risk in men with low levels of testosterone, but the benefits from testosterone therapy may even lower this risk. We review here the recent studies that have garnered such intense scrutiny. This article is intended as a thorough review of testosterone levels and CV risk, providing the clinician with the facts needed to make informed clinical decisions in managing patients with clinical hypogonadism.

Androgen Modulates Functions of Endothelial Progenitor Cells through Activated Egr1 Signaling

Researches show that androgens have important effects on migration of endothelial cells and endothelial protection in coronary heart disease. Endothelial progenitor cells (EPCs) as a progenitor cell type that can differentiate into endothelial cells, have a critical role in angiogenesis and endothelial protection. The relationship between androgen and the functions of EPCs has animated much interest and controversy. In this study, we investigated the angiogenic and migratory functions of EPCs after treatment by dihydrotestosterone (DHT) and the molecular mechanisms as well. We found that DHT treatment enhanced the incorporation of EPCs into tubular structures formed by HUVECs and the migratory activity of EPCs in the transwell assay dose dependently. Moreover, microarray analysis was performed to explore how DHT changes the gene expression profiles of EPCs. We found 346 differentially expressed genes in androgen-treated EPCs. Angiogenesis-related genes like Egr-1, Vcan, Efnb2, and Cdk2ap1 were identified to be regulated upon DHT treatment. Furthermore, the enhanced angiogenic and migratory abilities of EPCs after DHT treatment were inhibited by Egr1-siRNA transfection. In conclusion, our findings suggest that DHT markedly enhances the vessel forming ability and migration capacity of EPCs. Egr1 signaling may be a possible pathway in this process.

Central and peripheral testosterone effects in men with heart failure: An approach for cardiovascular research

Heart failure (HF) is a syndrome recognized as a health problem worldwide. Despite advances in treatment, patients with HF still have increased morbidity and mortality. Testosterone is one of the most researched hormones in the course of HF. Growing interest regarding the effect of testosterone, on a variety of body systems, has increased the knowledge about its mechanisms of action. The terms central and peripheral effects are used to distinguish the effects of testosterone on cardiac and extracardiac structures. Central effects include influences on cardiomyocytes and electrophysiology. Peripheral effects include influences on blood vessels, baroreceptor reactivity, skeletal muscles and erythropoesis. Current knowledge about peripheral effects of testosterone may explain much about beneficiary effects in the pathophysiology of HF syndrome. However, central, i.e., cardiac effects of testosterone are to be further explored.

A review of the relationships between endogenous sex steroids and incident ischemic stroke and coronary heart disease events

For decades, it has been recognized that men have a higher age-adjusted risk of ischemic cardiovascular (CVD) events compared to women, thus generating hypotheses that sex steroids contribute to CVD risk. Potential mechanisms include genomic and non-genomic effects of sex steroids as well as mediation through classic CVD risk factors and obesity. However, results from randomized studies suggest that sex steroid supplementation in men and women do not result in improved CVD outcomes and may increase CVD risk. In contrast, prospective observations from endogenous sex steroid studies, i.e. among participants not using sex steroids, have suggested the opposite relationship. We reviewed the findings of prospective observational studies in men (17 studies) and women (8 studies) that examined endogenous sex steroids and CVD risk. These studies suggested a lack of association or that lower levels of testosterone or dihydrotestosterone are associated with higher CVD risk in both men and women. Higher, rather than lower, estradiol levels were associated with higher CVD risk in women. There were several significant gaps in the literature. First, it is unclear whether more sensitive measures of sex steroid levels might detect significant differences. Second, there are few prospective studies in women. Similarly, no studies report outcomes for high-risk groups such as African-Americans and Hispanics. Finally, few studies report upon ischemic coronary disease as opposed to ischemic stroke separately, although relationships between sex steroids and CVD may vary by vascular bed. Future investigations need to examine high risk groups and to distinguish between subtypes of CVD.

Regular exercise improves cardiac contractile activation by modulating MHC isoforms and SERCA activity in orchidectomized rats

Data from the trial known as Testosterone in Older Men with Mobility Limitations (TOM) has indicated an association between testosterone administration and a greater risk for adverse cardiovascular events. We therefore propose that regular exercise is a cardioprotective alternative that prevents detrimental changes in contractile activation when a deficiency in male sex hormones exists. Ten-week-old orchidectomized (ORX) rats were subjected to a 9-wk treadmill running program at moderate intensity starting 1 wk after surgery. Although exercise-induced cardiac hypertrophy was observed both in rats that underwent ORX and sham surgery, regular exercise enhanced cardiac myofilament Ca(2+) sensitivity and myosin light-chain 2 phosphorylation only in rats that underwent a sham operation. Although the rats that had sham surgery and and given exercise exhibited no change in maximum developed tension, regular running prevented the suppression of maximum active tension in the hearts of ORX rats. Regular exercise also prevented a shift in myosin heavy chain (MHC) isoforms toward β-MHC, a reduction in sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) activity, and an increase in SERCA sensitivity in the hearts of ORX rats. Neither SERCA content nor its modulating component, phospholamban (PLB), was altered by exercise in either sham-operated or ORX rats. However, decreases in the phosphorylated Thr(17) form of PLB and the phosphorylated Thr(287) form of Ca(2+)/calmodulin-dependent kinase II in the hearts of ORX rats were abolished after regular exercise. These results thus support the use of regular running as a cardioprotective alternative to testosterone replacement in hypogonadal conditions.

Testosterone and cardiovascular disease risk

PURPOSE OF REVIEW

Ageing is accompanied by a reduction in circulating testosterone and progressive accumulation of medical morbidities. There is an intense debate whether low testosterone contributes to ill-health as opposed to being a biomarker for its presence. Prescriptions for testosterone are rising on a background of concern over potential adverse effects. This review examines evidence relating androgens to cardiovascular risk in older men.

RECENT FINDINGS

Observational studies show lower risk of cardiovascular events in older men with higher testosterone, and lower mortality from ischaemic heart disease in men with higher concentrations of its more potent androgenic metabolite dihydrotestosterone. However, randomized controlled trials of testosterone supplementation have been underpowered for the outcome of cardiovascular events. Recent meta-analyses have reached contrasting conclusions regarding cardiovascular adverse events associated with testosterone therapy. Retrospective studies of prescription databases have produced controversial and conflicting results.

SUMMARY

Additional randomized controlled trials are required to clarify the role of testosterone supplementation in older men in the absence of pituitary or gonadal disease. Pending such studies, testosterone therapy should be considered in androgen-deficient men, with evaluation of potential benefits and risks.