Endogenous testosterone and its relationship to preclinical and clinical measures of cardiovascular disease in the atherosclerosis risk in communities study

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

INTRODUCTION

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

FINDINGS

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

CONCLUSION

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

Association between life's essential 8 and male biochemical androgen deficiency: evidence from NHANES 2013-2016

Purpose

To evaluate the association of Life's Essential 8 (LE8) and its subscales with male biochemical androgen deficiency (MBAD) and total testosterone based on the data from the national health and nutrition examination survey (NHANES) database.

Methods

Data of males aged 20 years or older from NHANES of 2013-2016 were extracted. LE8 score was calculated based on American Heart Association definitions. Total testosterone (TT) values were measured in NHANES using precise isotope dilution liquid chromatography. MBAD was defined as serum TT of <300 ng/dL. Univariate and multivariable analyses were conducted. Propensity score matching (PSM) and weighted regression after matching were added as sensitivity analyses. The generalized additive model, smooth curve fitting, and the recursive algorithm were used to determine the potential inflection points. Piecewise regression models with log-likelihood ratio test were used to quantify nonlinear effects.

Results

A total of 3094 participants who were males and aged 20 years or above were included. Out of them, 805 males were diagnosed with MBAD. After adjusting the confounders in the multivariable model, LE8 was independently associated with MBAD (OR 0.96, P < 0.001) and TT (β 2.7, P < 0.001). The association remained robust even after PSM. The non-linear relationship of LE8 behaviors score with MBAD and TT was revealed.

Conclusion

LE8 was an independent protective factor of MBAD and a feasible approach to promote male endocrine sexual function.

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).

The association between serum testosterone level and congestive heart failure in US male adults: data from National Health and Nutrition Examination Survey (NHANES) 2011-2016

BACKGROUND

This study aimed to investigate the relationship between serum testosterone levels and the risk of congestive heart failure (CHF) in adult males. Previous research has suggested a potential link between serum testosterone and cardiovascular health, but the findings have been inconclusive.

METHODS

This study was cross-sectional, and the data were obtained from the 2011-2016 cycle of the National Health and Nutrition Examination Survey (NHANES), which included a sample of 6,841 male participants. Serum testosterone levels were measured using a standardized assay, and CHF status was assessed through self-reporting. Covariates such as age, ethnicity, lifestyle factors, and health conditions were considered in the analysis.

RESULTS

Among the participants, 242 individuals had a documented history of CHF. We observed a linear correlation between serum testosterone levels and CHF occurrence, with higher serum testosterone levels associated with a decreased risk of CHF (Q4 vs. Q1, OR = 0.29, 95% CI: 0.19-0.47, P < 0.001). After adjusting for confounding variables, multivariate analysis revealed that high serum testosterone levels remained significantly associated with a lower risk of CHF (OR: 0.47, 95% CI: 0.27-0.80, P = 0.01). Subgroup analysis indicated a significant association between high serum testosterone levels and reduced CHF risk in individuals over 50 years old.

CONCLUSION

Our findings suggest that the serum testosterone level was positively associated with CHF in adult males. This study highlights the potential role of serum testosterone in cardiovascular health, particularly in older individuals. Further research is needed to elucidate the underlying mechanisms and explore the clinical implications of these findings.

New Horizons: Testosterone or Exercise for Cardiometabolic Health in Older Men

Middle-aged and older men have typically accumulated comorbidities, are increasingly sedentary, and have lower testosterone concentrations (T) compared to younger men. Reduced physical activity (PA) and lower T both are associated with, and may predispose to, metabolically adverse changes in body composition, which contribute to higher risks of cardiometabolic disease. Exercise improves cardiometabolic health, but sustained participation is problematic. By contrast, rates of T prescription have increased, particularly in middle-aged and older men without organic diseases of the hypothalamus, pituitary, or testes, reflecting the unproven concept of a restorative hormone that preserves health. Two recent large randomized trials of T, and meta-analyses of randomized trials, did not show a signal for adverse cardiovascular (CV) events, and T treatment on a background of lifestyle intervention reduced type 2 diabetes by 40% in men at high risk. Men with both higher endogenous T and higher PA levels have lower CV risk, but causality remains unproven. Exercise training interventions improve blood pressure and endothelial function in middle-aged and older men, without comparable benefits or additive effects of T treatment. Therefore, exercise training improves cardiometabolic health in middle-aged and older men when effectively applied as a supervised regimen incorporating aerobic and resistance modalities. Treatment with T may have indirect cardiometabolic benefits, mediated via favorable changes in body composition. Further evaluation of T as a pharmacological intervention to improve cardiometabolic health in aging men could consider longer treatment durations and combination with targeted exercise programs.

The Beneficial Changes on Inflammatory and Endothelial Biomarkers Induced by Metabolic Surgery Decreases the Carotid Intima-Media Thickness in Men

Obesity increases cardiovascular risk in men through several mechanisms. Among them, low-grade chronic inflammation and obesity-associated hypogonadism have been described. We aimed to study the effects of metabolic surgery on the carotid-intima media thickness through changes in inflammatory, endothelial biomarkers, and testosterone. We included 60 men; 20 submitted to laparoscopic Roux-en-Y gastric bypass (RYGB), 20 to sleeve gastrectomy (SG), and 20 to lifestyle modification (controls). Several inflammatory and endothelial biomarkers and total testosterone (TT) were measured at baseline and six months after surgery. Free testosterone (FT) was calculated, and carotid intima-media thickness (cIMT) was measured by ultrasonography. Compared to controls, cIMT decreased after surgery concomitantly with CRP, PAI-1, sICAM-1, and IL-18 (p < 0.01) and with an increase in sTWEAK (p = 0.027), with no differences between RYGB and SG. The increase in TT and FT after surgery correlated with the changes in cIMT (p = 0.010 and p = 0.038, respectively), but this association disappeared after multivariate analysis. Linear regression showed that sTWEAK (ß = -0.245, p = 0.039), PAI-1 (ß = 0.346, p = 0.005), and CRP (ß = 0.236, p = 0.049) were associated with the changes in cIMT (R² = 0.267, F = 6.664, p = 0.001). In conclusion, both RYGB and SG induced improvements in inflammation and endothelial biomarkers that drove a decrease in cIMT compared to men with obesity who submitted to diet and exercise.

Relationships between endogenous and exogenous testosterone and cardiovascular disease in men

In this narrative review, we discuss the evidence about the controversy about the cardiovascular effects of endogenous and exogenous testosterone in men. Prospective cohort studies with follow-up of ~5-15 years generally indicate no association or a possible inverse relationship between serum endogenous testosterone concentrations and composite major cardiovascular events, cardiovascular deaths and overall mortality. Pharmacoepidemiological studies of large databases generally show no association between testosterone therapy and incident major cardiovascular events, and some pharmacoepidemiological studies demonstrate an association with decreased overall mortality. Randomized, placebo-controlled trials indicate that there is no increased incidence of overall major cardiovascular events with 1-3 years of testosterone therapy. These placebo-controlled trials have major limitations including small numbers of participants, short duration of testosterone therapy and follow-up, and lack of systematic adjudication of cardiovascular events. Overall, the evidence indicates that endogenous testosterone concentrations and testosterone therapy at physiological dosages confer no or minimal effects on the incidence of cardiovascular outcomes. There is insufficient evidence to make conclusions about testosterone therapy for patients at high risk of cardiovascular events (e.g., men with recent myocardial infarctions or stroke and men with recurrent idiopathic deep venous thromboses). In general, clinicians should avoid prescribing supraphysiological testosterone therapy to hypogonadal men or men with slightly low to low-normal serum testosterone concentrations and no identified disorder of the hypothalamus-pituitary-testicular axis because of the uncertain cardiovascular risks and the lack of proven health benefits. For most men with bona fide hypogonadism, benefits of testosterone therapy exceed the potential risk of adverse cardiovascular effects.

Endogenous Risk Factors of Cardiovascular Diseases (CVDs) in Military Professionals with a Special Emphasis on Military Pilots

Cardiovascular disease (CVD) risk factors can be categorized as non-modifiable and modifiable. Modifiable risk factors include some exogenous and behavioral factors that can be easily modified, whereas endogenous modifiable risk factors, such as hypertension, hyperlipidemia, diabetes, or obesity may be modified to a limited extend. An increased prevalence of CVDs as well as their risk factors have been observed in military personnel, as specific military-related stressors are highly correlated with acute cardiac disorders. Military pilots are a subpopulation with great CVD risk due to an accumulation of different psychological and physical stressors also considered to be CVD risk factors. This review presents data concerning CVD risk in military professionals, with a special emphasis on military pilots and crew members. We also discuss the usefulness of novel indicators related to oxidative stress, inflammation, or hormonal status as well as genetic factors as markers of CVD risk. For a correct and early estimation of CVD risk in asymptomatic soldiers, especially if no environmental risk factors coexist, the scope of performed tests should be increased with novel biomarkers. An indication of risk group among military professional, especially military pilots, enables the implementation the early preventive activities, which will prolong their state of health and military suitability.

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.

Clinical characteristics and comorbidities associated with testosterone prescribing in men

OBJECTIVE

Testosterone replacement therapy (TRT) is recommended for the treatment of symptomatic hypogonadism in men. Data on prescription behaviours are, however, limited and conflicting. The objective of this study was to investigate clinical characteristics associated with the likelihood of being prescribed TRT by general practitioners (GP) in North-West London (NWL).

DESIGN

Retrospective cohort study using Discover database of GP-registered patients in NWL between 2015 and 2019.

PATIENTS

We identified 20,299 men aged ≥18 years with serum total testosterone measurement (TT) and without prior TRT prescription records.

MEASUREMENTS

We determined whether TRT was subsequently commenced, while analysing clinical characteristics related to hypogonadism.

RESULTS

Of all men having TT measurement, 19,583 (96.4%) were not commenced on TRT (Group A) and 716 (3.5%) men were commenced on TRT (Group B). Men prescribed TRT (Group B) had higher mean age, body mass index (BMI) and higher risks of hypertension, depression type 2 diabetes and ischaemic heart disease; conversely, men in Group B had lower mean pretreatment TT and were less likely to have prostate cancer. Four-hundred and thirty-six men (24.3%) with TT < 8 nmol/L and symptoms of low libido were not prescribed TRT.

CONCLUSIONS

Our study highlights several factors which may influence the decisions made by clinicians when initiating TRT in primary care. Clearer guidance for clinicians may help to improve the consistency of treatment of men with hypogonadism.

Systematic review and meta-analyses on associations of endogenous testosterone concentration with health outcomes in community-dwelling men

OBJECTIVES

The overall study aim is to clarify the relation of endogenous sex hormones with major health outcomes in men. This paper reports a systematic review focusing on published estimates for testosterone associations.

SETTING

Community-dwelling men.

PARTICIPANTS

20 180 adult men participated in the final set of studies identified and selected from a systematic review. Eligible studies included prospective cohort studies with plasma or serum testosterone concentrations measured for adult men using mass spectrometry with at least 5 years of follow-up data and one of the specified outcome measures recorded. Only published or grey literature items written in English were considered.

PRIMARY AND SECONDARY OUTCOME MEASURES

Planned prospective outcome measures: cardiovascular disease (CVD) events, CVD deaths, all-cause mortality, cancer deaths, cancer diagnoses, cognitive decline, dementia. Meta-analyses were of the most frequently reported outcomes in selected studies: CVD deaths and all-cause mortality. Succinct characterisations of testosterone associations with other outcomes are also presented.

RESULTS

Screening of 1994 deduplicated items identified 9 suitable studies, with an additional 2 identified by colleagues (11 in total). Summary estimates of mean testosterone concentration and age at recruitment for 20 180 adult men were 15.4±0.7 nmol/L and 64.9±3.3 year. Despite considerable variation in mean testosterone, a metaregression estimated no significant dependence on mean age at recruitment among studies (slope=-0.03, 95% CI -0.11 to 0.06). Meta-analyses demonstrated negligible heterogeneity and no significant effect of a 5 nmol/L increase in testosterone on the risk of all-cause mortality (HR=0.96, 95% CI 0.89 to 1.03) or death from CVD (HR=0.95, 95% CI 0.83 to 1.08).

CONCLUSIONS

Analyses of published estimates did not demonstrate associations of endogenous testosterone with CVD deaths or with all-cause mortality. Suggested further research includes the planned individual participant data meta-analyses for selected studies, enabling the investigation of non-linear summary effects.

PROSPERO REGISTRATION NUMBER

PROSPERO: CRD42019139668.

Anabolic-Androgenic Steroid Use in Sports, Health, and Society

This consensus statement is an update of the 1987 American College of Sports Medicine (ACSM) position stand on the use of anabolic-androgenic steroids (AAS). Substantial data have been collected since the previous position stand, and AAS use patterns have changed significantly. The ACSM acknowledges that lawful and ethical therapeutic use of AAS is now an accepted mainstream treatment for several clinical disorders; however, there is increased recognition that AAS are commonly used illicitly to enhance performance and appearance in several segments of the population, including competitive athletes. The illicit use of AAS by competitive athletes is contrary to the rules and ethics of many sport governing bodies. Thus, the ACSM deplores the illicit use of AAS for athletic and recreational purposes. This consensus statement provides a brief history of AAS use, an update on the science of how we now understand AAS to be working metabolically/biochemically, potential side effects, the prevalence of use among athletes, and the use of AAS in clinical scenarios.

LncRNA FENDRR promotes apoptosis of Leydig cells in late-onset hypogonadism by facilitating the degradation of Nrf2

This study aimed to investigate the role of lncRNA FENDRR in apoptosis of Leydig cells and the further mechanism. The apoptosis of Leydig cells (TM3 cell line) was induced by H₂O₂-treatment and detected by flow cytometry. The function of FENDRR was determined by in vitro and in vivo silencing experiments. The mechanism of FENDRR in regulating the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) was assessed by RNA immunoprecipitation, RNA pull-down, and ubiquitination assays. FENDRR expression was up-regulated in H₂O₂-treated TM3 cells. Knockdown of FENDRR augmented Nrf2 and HO-1 protein levels and testosterone production in H₂O₂-treated TM3 cells, whereas the apoptosis rate and caspase 3 activity were decreased. Mechanically, FENDRR bound to Nrf2 and promoted its ubiquitination and degradation. Nrf2 overexpression reversed the effects FENDRR overexpression on apoptosis, caspase 3 activity, and testosterone concentration in H₂O₂-treated TM3 cells. The in vivo experiments showed that FENDRR silence increased serum testosterone level and improved testosterone-related anti-depression behaviors of late-onset hypogonadism (LOH) mice. Our findings suggested that FENDRR could promote apoptosis of Leydig cells in LOH partly through facilitating Nrf2 degradation.

Testosterone replacement therapy in men with type 2 diabetes mellitus and functional hypogonadism -an Integrated Diabetes and Endocrine Academy (IDEA) consensus guideline

BACKGROUND

Though testosterone replacement therapy in men with organic hypogonadism is established, its role in men with type 2 diabetes mellitus (T2DM) and functional hypogonadism is unclear.

METHODS

Thirteen experts addressed ten topic-specific questions after an in-depth review of literature, where all relevant issues were critically evaluated.

RESULTS

Ten recommendations concerning diagnosis and management of men with T2DM and functional hypogonadism have been put forward.

CONCLUSION

Routine measurement of serum testosterone in all, and inappropriate replacement of testosterone in asymptomatic T2DM men with functional hypogonadism and borderline low serum testosterone values, is not recommended.

Pituitary Dysfunction as a Cause of Cardiovascular Disease

The hypothalamic-pituitary axis is responsible for the neuroendocrine control of several organ systems. The anterior pituitary directly affects the functions of the thyroid gland, the adrenal glands, and gonads, and regulates growth and milk production. The posterior hypophysis, through nerve connections with the hypothalamic nuclei, releases vasopressin and oxytocin responsible for water balance and social bonding, sexual reproduction and childbirth, respectively. Pituitary gland hormonal excess or deficiency results in dysregulation of metabolic pathways and mechanisms that are important for the homeostasis of the organism and are associated with increased morbidity and mortality. Cardiovascular (CV) disorders are common in pituitary disease and have a significant impact on survival. Hormonal imbalance is associated with CV complications either through direct effects on the heart structure and function and vasculature or indirectly by altering the metabolic profile. Optimal endocrine control can prevent or reverse CV defects and preserve survival and quality of life. In this review, we discuss the effects of pituitary hormone excess and deficiency on the CV system. Specifically, we assess the impact of Somatotroph, Corticotroph, Gonadotroph, and Lactotroph anterior pituitary axes on the CV system. The effect of posterior pituitary function on the CV system is also explored.

Low Serum-Free Testosterone Concentration in Chinese Male Patients with Uncomplicated Acute Type B Aortic Dissection

OBJECTIVE

Although aortic dissection occurs predominantly in men, its association with androgens is unknown. The aim of this study was to evaluate the androgen levels in Chinese male patients with uncomplicated, acute type B aortic dissection.

STUDY DESIGN

Cross-sectional study.

MATERIALS AND METHODS

A total of 192 age-matched male patients with uncomplicated, acute type B aortic dissection or essential hypertension were recruited between 2016 and 2018. The demographic and clinical data were analyzed.

RESULTS

Male patients with uncomplicated, acute type B aortic dissection had lower serum total testosterone and free testosterone than male patients with essential hypertension (7.6 ± 3.7 nmol/L vs. 10.9 ± 3.8 nmol/L, P < 0.001; 36.0 ± 19.8 pmol/L vs. 56.4 ± 19.2 pmol/L, P < 0.001). Lower free testosterone level was significantly associated with uncomplicated, acute type B aortic dissection (univariate odds ratio 0.948, P < 0.001; multivariate odds ratio = 0.966, P = 0.002). No statistical difference was observed for free testosterone between younger patient groups (aged < 51 years; aged 51-60 years) and older patient groups (aged 61-70 years; aged >70 years) with uncomplicated, acute type B aortic dissection (33.7 ± 19.8 pmol/L vs. 38.5 ± 19.8 pmol/L, P = 0.239).

CONCLUSIONS

Lower free testosterone was independently associated with uncomplicated, acute type B aortic dissection in the Chinese male population with hypertension. Additional studies are needed to clarify whether earlier onset in Chinese patients with aortic dissection is associated with androgen deficiency.

Recent testosterone drop-off and risk of cardiovascular events

Low baseline testosterone level has been associated with the development of risk factors for cardiovascular disease such as insulin resistance and obesity. In addition to the absolute testosterone level, remarkable changes in testosterone level may have an acute effect on cardiovascular disease development and progression, which has been rarely investigated. In this study, we used a clinical dataset of 376 hypogonadal men whose testosterone levels were measured every six months for up to 11 years from a registry study in Germany, and conducted survival analyses to investigate the effect of testosterone changes since the last visit (time-varying) on the risk of cardiovascular events. Given the potential discrepancies in comorbidity conditions among patients with prior cardiovascular events and those without, all the analyses were stratified by patients' prior cardiovascular event status. We found the effects were not different among patients with prior cardiovascular events and those without. Regardless of patients' prior cardiovascular event status, patients with larger testosterone declines (≥3.12 nmol/L, 90^th percentile) since the last visit were more likely to experience myocardial infarction. In conclusion, recent pronounced testosterone drop-offs may affect the risk of cardiovascular events among hypogonadal men. Future longitudinal studies are needed to confirm our exploratory study findings.

Sex Hormones and Incident Heart Failure in Men and Postmenopausal Women: The Atherosclerosis Risk in Communities Study

CONTEXT

Sex differences exist in heart failure (HF) phenotypes, but there is limited research on the role of sex hormones in HF and its subtypes.

OBJECTIVE

To examine the associations of total testosterone, dehydroepiandrosterone sulfate (DHEA-S), and sex hormone-binding globulin (SHBG) with incident HF, HF with preserved ejection fraction (HFpEF), and HF with reduced ejection fraction (HFrEF).

DESIGN

Atherosclerosis Risk in Communities (ARIC) study (prospective cohort study). Median follow-up is 19.2 years.

SETTING

General community.

PARTICIPANTS

4107 men and 4839 postmenopausal women, with mean age of 63.2 (standard deviation [SD] 5.7) and 62.8 (5.5) years, respectively.

EXPOSURE

Plasma sex hormone levels were measured at visit 4 (1996-1998).

MAIN OUTCOME MEASURES

Incident HF events were identified through hospital discharge codes and death certificates.

RESULTS

The Hazard Ratios for HF associated with 1 SD decrease in log-transformed total testosterone, DHEA-S, and SHBG were 1.10 (95% confidence interval 1.03, 1.17), 1.07 (1.00, 1.15), and 1.04 (0.96, 1.11) in men, and 1.05 (0.99, 1.13), 1.17 (1.09, 1.24), and 0.93 (0.85, 1.01) in women, respectively. The associations between sex hormones with subtypes of HF had similar patterns but were attenuated and became statistically insignificant.

CONCLUSION

In this prospective cohort, lower levels of endogenous testosterone and DHEA-S in men and DHEA-S in postmenopausal women were associated with the development of HF. Similar directions of association in both sexes and both HF subtypes suggest that sex hormones play a role in the development of HF through common pathways regardless of sex.

Androgens In Men Study (AIMS): protocol for meta-analyses of individual participant data investigating associations of androgens with health outcomes in men

INTRODUCTION

This study aims to clarify the role(s) of endogenous sex hormones to influence health outcomes in men, specifically to define the associations of plasma testosterone with incidence of cardiovascular events, cancer, dementia and mortality risk, and to identify factors predicting testosterone concentrations. Data will be accrued from at least three Australian, two European and four North American population-based cohorts involving approximately 20 000 men.

METHODS AND ANALYSIS

Eligible studies include prospective cohort studies with baseline testosterone concentrations measured using mass spectrometry and 5 years of follow-up data on incident cardiovascular events, mortality, cancer diagnoses or deaths, new-onset dementia or decline in cognitive function recorded. Data for men, who were not taking androgens or drugs suppressing testosterone production, metabolism or action; and had no prior orchidectomy, are eligible. Systematic literature searches were conducted from 14 June 2019 to 31 December 2019, with no date range set for searches. Aggregate level data will be sought where individual participant data (IPD) are not available. One-stage IPD random-effects meta-analyses will be performed, using linear mixed models, generalised linear mixed models and either stratified or frailty-augmented Cox regression models. Heterogeneity in estimates from different studies will be quantified and bias investigated using funnel plots. Effect size estimates will be presented in forest plots and non-negligible heterogeneity and bias investigated using subgroup or meta-regression analyses.

ETHICS AND DISSEMINATION

Ethics approvals obtained for each of the participating cohorts state that participants have consented to have their data collected and used for research purposes. The Androgens In Men Study has been assessed as exempt from ethics review by the Human Ethics office at the University of Western Australia (file reference number RA/4/20/5014). Each of the component studies had obtained ethics approvals; please refer to respective component studies for details. Research findings will be disseminated to the scientific and broader community via the publication of four research articles, with each involving a separate set of IPD meta-analyses (articles will investigate different, distinct outcomes), at scientific conferences and meetings of relevant professional societies. Collaborating cohort studies will disseminate findings to study participants and local communities.

PROSPERO REGISTRATION NUMBER

CRD42019139668.

Endogenous Testosterone Levels and the Risk of Incident Cardiovascular Events in Elderly Men: The MrOS Prospective Study

Context

Observational studies show discordant links between endogenous testosterone levels and cardiovascular diseases (CVD).

Objective

We assessed whether sex hormones and sex hormone–binding globulin (SHBG) are associated with CVD in community-dwelling elderly men.

Design, Setting and Participants

Prospective study of incident CVD among 552 men ≥ 65 years in the MrOS Sleep Study without prevalent CVD and no testosterone therapy at baseline.

Outcomes

Fasting serum levels of total testosterone and estradiol were measured using liquid chromatography-mass spectrometry, and SHBG by chemiluminescent substrate. The association of sex hormones and SHBG with incident coronary heart disease (CHD), cerebrovascular (stroke and transient ischemic attack) and peripheral arterial disease (PAD) events were assessed by quartile and per SD increase in proportional hazards models.

Results

After 7.4 years, 137 men (24.8%) had at least 1 CVD event: 90 CHD, 45 cerebrovascular and 26 PAD. The risk of incident CVD events was not associated with quartiles of baseline sex hormones or SHBG (all P ≥ 0.16). For +1 SD in total testosterone, the multivariate-adjusted hazard ratio was 1.04 (95% CI, 0.80-1.34) for CHD, 0.86 (0.60-1.25) for cerebrovascular, and 0.81 (0.52-1.26) for PAD events. When analyzed as continuous variables or comparing highest to low quartile, levels of bioavailable testosterone, total estradiol, testosterone/estradiol ratio and SHBG were not associated with CVD events.

Conclusions

In community-dwelling elderly men, endogenous levels of testosterone, estradiol, and SHBG were not associated with increased risk of CHD, cerebrovascular, or PAD events. These results are limited by the small number of events and should be explored in future studies.

Higher Serum Sex Hormone-Binding Globulin Levels Are Associated With Incident Cardiovascular Disease in Men

CONTEXT

Sex hormone-binding globulin (SHBG) levels are associated with cardiovascular disease (CVD) risk factors. However, prospective data on the association between SHBG levels and CVD events are sparse, with conflicting results.

OBJECTIVES

To examine associations between serum SHBG, total testosterone (TT), and incident CVD and CVD-related mortality in middle-aged to elderly men.

DESIGN AND METHODS

Data on 2563 community-dwelling men (35 to 80 years) were obtained from participants in the Men Androgen Inflammation Lifestyle Environment and Stress cohort. The analytic sample included 1492 men without baseline (2002 to 2007) CVD and with fasted morning serum SHBG and TT available at both baseline and follow-up (2007 to 2010) and without medications affecting TT or SHBG. Associations of baseline SHBG and TT, with incident CVD and CVD mortality, were analyzed using logistic regression for incident CVD and Cox proportional hazard regression for CVD mortality, adjusting for established CVD risk factors.

RESULTS

In multivariable models, elevated baseline SHBG and lower baseline TT were independently associated with incident CVD (SHBG: OR, 1.54; 95% CI, 1.15 to 2.06 per SD increase in SHBG, P = 0.003; TT: OR, 0.71; 95% CI, 0.52 to 0.97 per SD decrease in TT; P = 0.03). A decrease in TT between time points was associated with incident CVD (OR, 0.72; 95% CI, 0.56 to 0.92; P = 0.01). Neither SHBG nor TT was significantly associated with all-age CVD mortality [hazard ratio (HR), 0.69; 95% CI, 0.29 to 1.63; P = 0.40; and HR, 0.60; 95% CI, 0.28 to 1.26; P = 0.18, respectively].

CONCLUSIONS

Among all men and men >65 years, elevated SHBG and lower TT were independently associated with both a greater risk of CVD and an increased CVD mortality risk.

Characteristics of atheromatosis in the prediabetes stage: a cross-sectional investigation of the ILERVAS project

Background

Prediabetes has recently been associated with subclinical atheromatous disease in the middle-aged population. Our aim was to characterize atheromatous plaque burden by the number of affected territories and the total plaque area in the prediabetes stage.

Methods

Atheromatous plaque burden (quantity of plaques and total plaque area) was assessed in 12 territories from the carotid and femoral regions using ultrasonography in 6688 non-diabetic middle-aged subjects without cardiovascular disease. Prediabetes was defined by glycosylated hemoglobin (HbA1c) between 5.7 and 6.4% according to the American Diabetes Association guidelines.

Results

Prediabetes was diagnosed in 33.9% (n = 2269) of the ILERVAS participants. Subjects with prediabetes presented a higher prevalence of subclinical atheromatous disease than participants with HbA1c < 5.7% (70.4 vs. 67.5%, p = 0.017). In the population with prediabetes this was observed at the level of the carotid territory (p < 0.001), but not in the femoral arteries. Participants in the prediabetes stage also presented a significantly higher number of affected territories (2 [1;3] vs. 1 [0;3], p = 0.002), with a positive correlation between HbA1c levels and the number of affected territories (r = 0.068, p < 0.001). However, atheromatosis was only significantly (p = 0.016) magnified by prediabetes in those subjects with 3 or more cardiovascular risk factors. The multivariable logistic regression model showed that the well-established cardiovascular risk factors together with HbA1c were independently associated with the presence of atheromatous disease in participants with prediabetes. When males and females were analyzed separately, we found that only men with prediabetes presented both carotid and femoral atherosclerosis, as well as an increase of total plaque area in comparison with non-prediabetic subjects.

Conclusions

The prediabetes stage is accompanied by an increased subclinical atheromatous disease only in the presence of other cardiovascular risk factors. Prediabetes modulates the atherogenic effect of cardiovascular risk factors in terms of distribution and total plaque area in a sex-dependent manner.

Trial registration NCT03228459 (clinicaltrials.gov)

Resting heart rate is associated with metabolic syndrome and predicted 10-year risk of cardiovascular disease: a cross-sectional study

BACKGROUND

This study examined whether resting heart rate (RHR) was associated with metabolic syndrome (MetS) and the 10-year predicted risk of cardiovascular disease in a Chinese population.

METHODS

The associations of RHR with MetS and 10-year risk of atherosclerotic cardiovascular diseases (ASCVD) was examined in a cross-sectional study conducted in Shanghai, China (n = 9486).

RESULTS

Compared with individuals in the lowest RHR quintile (≤71 b.p.m.), those in the highest quintile (≥91 b.p.m.) had a higher prevalence of MetS (21.2% vs 32.6%, respectively; P < 0.001). Logistic regression analyses showed that the multivariate-adjusted odds ratio (OR) and 95% confidence interval (CI) for MetS was 1.13 (1.08-1.18) for each 10-b.p.m. increment of RHR (P < 0.0001). Furthermore, RHR was strongly associated with the prevalence of hypertension, high blood glucose, and dyslipidemia, but not with central obesity. A stronger association of RHR with MetS was observed among individuals aged <65 years, male, with a body mass index <24 kg/m² , without diabetes, hypertension, abnormal lipids, and insulin resistance than among their counterparts (P < 0.05 for all). A significantly higher 10-year risk for ASCVD was observed with each 10-b.p.m. increment in RHR in both men and women (ORs [95% CIs] 1.20 [1.07-1.33] and 1.28 [1.17-1.39], respectively; P_trend  = 0.002 and < 0.0001, respectively).

CONCLUSIONS

In this study, RHR was associated with a higher prevalence of MetS and elevated 10-year predicted risk of ASCVD in both Chinese men and women. Whether RHR may serve as an indicator for MetS among relatively healthy individuals requires further investigation.

Aging and the Male Reproductive System

This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.

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.

Plasma total testosterone and risk of incident atrial fibrillation: The Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVE

Whether endogenous testosterone concentrations are associated with atrial fibrillation (AF) development is not well established. We assessed the association between plasma total testosterone concentrations and incident AF in a population-based longitudinal study.

STUDY DESIGN

Using data from the prospective Atherosclerosis Risk in Communities (ARIC) study, we identified incident AF among 9282 participants who had plasma total testosterone measured by liquid chromatography tandem mass spectrometry at Visit 4 (1996-1998).

MAIN OUTCOME MEASURES

AF cases were identified by electrocardiograms performed during study visits, hospital records/discharge codes, and death certificates through 2013. We estimated hazard ratios (HRs) and 95% confidence intervals (95% CIs) for incident AF across quartiles of plasma total testosterone, stratified by sex, with multivariable Cox models.

RESULTS

The mean age of the participant sample at ARIC Visit 4 was 63 years (range 52-75); 54.5% were women. Mean (SD) plasma total testosterone levels were 537 ng/dL (213) for men and 27.6 ng/dL (34.7) for women. Over a mean of 13.7 years of follow-up, 1664 incident cases of AF were identified. Comparing those in the highest quartile of plasma total testosterone concentration to those in the lowest quartile and after adjustment for potential confounding variables, there was a positive association between plasma total testosterone and incident AF in men (HR 1.33, 95% CI 1.07, 1.66), but no such association in women (HR 0.99, 95% CI 0.80, 1.22). Conclusion A higher plasma total testosterone concentration was associated with a modestly greater incidence rate of AF 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.

HC diet inhibited testosterone synthesis by activating endoplasmic reticulum stress in testicular Leydig cells

Emerging epidemiological studies indicate that hypercholesterolaemia is a risk factor for testosterone deficiency. However, the underlying mechanism is unclear. Testicular Leydig cells are the primary source of testosterone in males. To identify the effect and mechanism of cholesterol overload on Leydig cell function, rats were fed with a HC (HC) diet to induce hypercholesterolaemia. During the 16‐week feeding period, serum testosterone levels were reduced in a time‐dependent manner in rats fed the HC diet. Accordingly, these steroidogenic enzymes within the Leydig cells, including steroidogenic acute regulatory protein (StAR), cholesterol side‐chain cleavage cytochrome P450 (P450scc) and 3β‐hydroxysteroid dehydrogenase (3β‐HSD), were down‐regulated. Notably, the HC‐fed rats showed evident endoplasmic reticulum (ER) stress in the testis, including a dilated ER as an evident pathological change in the Leydig cell ultrastructure, up‐regulated ER stress biomarker (binding immunoglobulin protein) levels and activation of the activating transcription factor 6 (ATF6)‐related unfolded protein response pathway. Further analysis showed that when 4‐phenyl butyric acid (4‐PBA) was used to block ER stress in HC‐fed rats for 8 weeks, the testosterone deficiency was significantly alleviated. Our findings suggested that high dietary cholesterol intake affected serum testosterone levels by down‐regulating steroidogenic enzymes and that activated ER stress might serve as the underlying mechanism.

Cross-sectional and longitudinal associations between serum testosterone concentrations and hypertension: Results from the Fangchenggang Area Male Health and Examination Survey in China

BACKGROUND

Low testosterone concentrations have been suggested as a risk factor for hypertension, but their contribution to the development of hypertension is not well studied. We carried out a cohort study based on the results of an earlier cross-sectional investigation. We established the association between testosterone concentrations and hypertension.

METHOD

Data on 2427 healthy male subjects, aged from 17 to 88 y, were collected for the cross-sectional study. A representative sample of 853 individuals who did not suffer from hypertension at baseline was followed up for 4 y. Differences between the tertiles groups of sex hormones were analyzed, relative risks (RR) were estimated using binary logistic regression model.

RESULTS

In the cross-sectional analysis, the serum total testosterone (TT), free testosterone (FT), and bioavailable testosterone (BT) concentrations of the hypertensive population were lower than those of the non-hypertensive population. Binary logistic regression analysis showed that TT, BT, and FT were inversely associated with hypertension. Moreover, decreasing odds ratio (OR) was observed from the lowest tertile group to the highest tertile group. After multivariate adjustment, the correlation between FT, BT, and hypertension was attenuated. Statistically significant differences remained only in the middle tertile group of TT and in the highest tertile group of TT, FT, and BT. In the longitudinal analysis, the 4-y incidence of hypertension was higher in participants with lower TT than in those with higher TT. Subjects in the middle and highest tertile groups of TT had an RR of 0.35 (0.22-0.57) and 0.30 (0.18-0.50), respectively (P for trend <0.001). After further adjustments, these associations still remained statistically significant.

CONCLUSIONS

Serum TT, FT, and BT concentrations were inversely associated with blood pressure in man, and TT independent of age and body mass index (BMI) influences the development of hypertension. Furthermore, TT can be employed as a risk marker for hypertension in the identification of high-risk individuals.

Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To update the "Testosterone Therapy in Men With Androgen Deficiency Syndromes" guideline published in 2010.

PARTICIPANTS

The participants include an Endocrine Society-appointed task force of 10 medical content experts and a clinical practice guideline methodologist.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications facilitated consensus development. Endocrine Society committees and members and the cosponsoring organization were invited to review and comment on preliminary drafts of the guideline.

CONCLUSIONS

We recommend making a diagnosis of hypogonadism only in men with symptoms and signs consistent with testosterone (T) deficiency and unequivocally and consistently low serum T concentrations. We recommend measuring fasting morning total T concentrations using an accurate and reliable assay as the initial diagnostic test. We recommend confirming the diagnosis by repeating the measurement of morning fasting total T concentrations. In men whose total T is near the lower limit of normal or who have a condition that alters sex hormone-binding globulin, we recommend obtaining a free T concentration using either equilibrium dialysis or estimating it using an accurate formula. In men determined to have androgen deficiency, we recommend additional diagnostic evaluation to ascertain the cause of androgen deficiency. We recommend T therapy for men with symptomatic T deficiency to induce and maintain secondary sex characteristics and correct symptoms of hypogonadism after discussing the potential benefits and risks of therapy and of monitoring therapy and involving the patient in decision making. We recommend against starting T therapy in patients who are planning fertility in the near term or have any of the following conditions: breast or prostate cancer, a palpable prostate nodule or induration, prostate-specific antigen level > 4 ng/mL, prostate-specific antigen > 3 ng/mL in men at increased risk of prostate cancer (e.g., African Americans and men with a first-degree relative with diagnosed prostate cancer) without further urological evaluation, elevated hematocrit, untreated severe obstructive sleep apnea, severe lower urinary tract symptoms, uncontrolled heart failure, myocardial infarction or stroke within the last 6 months, or thrombophilia. We suggest that when clinicians institute T therapy, they aim at achieving T concentrations in the mid-normal range during treatment with any of the approved formulations, taking into consideration patient preference, pharmacokinetics, formulation-specific adverse effects, treatment burden, and cost. Clinicians should monitor men receiving T therapy using a standardized plan that includes: evaluating symptoms, adverse effects, and compliance; measuring serum T and hematocrit concentrations; and evaluating prostate cancer risk during the first year after initiating T therapy.

Greater physical activity and higher androgen concentrations are independently associated with lower cardiometabolic risk in men

CONTEXT

Male ageing is associated with lower circulating testosterone (T) and increased incidence of cardiovascular disease (CVD). Whether physical activity (PA) interacts with hormones to modify CVD risk is unclear.

OBJECTIVE

We assessed whether PA and sex hormone concentrations were independently associated with measures of CVD risk.

PARTICIPANTS

A total of 1649 men.

METHODS

Leisure, home, work and total PA were ascertained. At baseline, serum T, dihydrotestosterone (DHT) and oestradiol (E2) were assayed. Men were stratified into high PA+high hormone (H/H); low PA+high hormone (L/H); high PA+low hormone (H/L); and low PA+low hormone (L/L).

RESULTS

Mean age was 49.8 years at outset with 415 CVD events and 127 CVD deaths occurring during 20-year follow-up. Men with higher PA and higher T or DHT had lower odds of metabolic syndrome (eg leisure H/H vs L/L odds ratio [OR] 0.17 P<.001 for T, 0.26 P<.001 for DHT). Men with higher PA and E2 had lower risk of metabolic syndrome (eg leisure PA H/H vs L/L OR 0.51, P=.001). Men with higher leisure, work or total PA and higher DHT had the lowest risk of CVD death (eg leisure H/H hazard ratio [HR] 0.55 vs L/L, P=.033). Men with lower leisure, home or work PA and higher E2 were at greater risk of CVD death (eg leisure L/H HR 1.60 vs L/L, P=.039).

CONCLUSIONS

Considering T, DHT and E2 in the context of PA better informs consideration of cardiovascular risk. A 2×2 factorial RCT assessing PA and androgens would illuminate the scope for preventing CVD in men.

Transplanted human p75-positive stem Leydig cells replace disrupted Leydig cells for testosterone production

Previous studies have demonstrated that rodent stem Leydig cell (SLC) transplantation can partially restore testosterone production in Leydig cell (LC)-disrupted or senescent animal models, which provides a promising approach for the treatment of hypogonadism. Here, we isolated human SLCs prospectively and explored the potential therapeutic benefits of human SLC transplantation for hypogonadism treatment. In adult human testes, p75 neurotrophin receptor positive (p75⁺) cells expressed the known SLC marker nestin, but not the LC lineage marker hydroxysteroid dehydrogenase-3β (HSD3β). The p75⁺ cells which were sorted by flow cytometry from human adult testes could expand in vitro and exhibited clonogenic self-renewal capacity. The p75⁺ cells had multi-lineage differentiation potential into multiple mesodermal cell lineages and testosterone-producing LCs in vitro. After transplantation into the testes of ethane dimethane sulfonate (EDS)-treated LC-disrupted rat models, the p75⁺ cells differentiated into LCs in vivo and secreted testosterone in a physiological pattern. Moreover, p75⁺ cell transplantation accelerated the recovery of serum testosterone levels, spermatogenesis and reproductive organ weights. Taken together, we reported a method for the identification and isolation of human SLCs on the basis of p75 expression, and demonstrated that transplanted human p75⁺ SLCs could replace disrupted LCs for testosterone production. These findings provide the groundwork for further clinical application of human SLCs for hypogonadism.

Association of Testosterone Replacement Therapy and the Incidence of a Composite of Postoperative In-hospital Mortality and Cardiovascular Events in Men Undergoing Noncardiac Surgery

Background

Whether patients on testosterone replacement therapy undergoing noncardiac surgery have an increased risk of postoperative in-hospital mortality and cardiovascular events remains unknown. We therefore sought to identify the impact of testosterone replacement on the incidence of a composite of postoperative in-hospital mortality and cardiovascular events in men undergoing noncardiac surgery.

Methods

Data from male American Society of Anesthesiologists I through IV patients 40 yr or older who underwent noncardiac surgery between May 2005 and December 2015 at the Cleveland Clinic (Cleveland, Ohio) main campus were included. The primary exposure was preoperative testosterone use. The primary outcome was a composite of postoperative in-hospital mortality and cardiovascular events. We compared patients who received testosterone and those who did not using propensity score matching within surgical procedure matches.

Results

Among 49,273 patients who met inclusion and exclusion criteria, 947 patients on testosterone were matched to 4,598 nontestosterone patients. The incidence of in-hospital mortality was 1.3% in the testosterone group and 1.1% in the nontestosterone group, giving an odds ratio of 1.17 (99% CI, 0.51 to 2.68; P = 0.63). The incidence of myocardial infarction was 0.2% in the testosterone group and 0.6% in the nontestosterone group (odds ratio = 0.34; 99% CI, 0.05 to 2.28; P = 0.15). Similarly, no significant difference was found in stroke (testosterone vs. nontestosterone: 2.0% vs. 2.1%), pulmonary embolism (0.5% vs. 0.7%), or deep venous thrombosis (2.0% vs. 1.7%).

Conclusions

Preoperative testosterone is not associated with an increased incidence of a composite of postoperative in-hospital mortality and cardiovascular events.

Androgens and cardiovascular disease in women and men

Cardiovascular disease is the leading cause of death in both women and men. Its pathogenesis is multifactorial, with sex hormones playing an important role. Androgens have both direct and indirect effects on the vasculature. This review summarizes evidence on the association of both endogenous and exogenous androgens with subclinical and overt cardiovascular disease in women and men. Concerning women, both high and low levels of endogenous androgens have been associated with cardiovascular disease, while other studies have reported no association. Adiposity, impaired glucose metabolism, dyslipidemia and estrogen levels may mediate the observed associations. Regarding testosterone therapy in women, there have been no large prospective studies on cardiovascular outcomes. Concerning men, most studies indicate that low levels of circulating testosterone are associated with increased rates of cardiovascular disease in the general population; the causality, however, of this association remains to be proven. Testosterone replacement therapy in men with symptoms of hypogonadism and low serum testosterone merits caution with regard to cardiovascular safety, as evidence is still conflicting.

ACTH and gonadotropin deficiencies predict mortality in patients treated for nonfunctioning pituitary adenoma: long-term follow-up of 519 patients in two large European centres

CONTEXT AND OBJECTIVE

Nonfunctioning pituitary adenomas (NFPAs) are the most common subtype of pituitary tumour. Hypopituitarism is observed in NFPAs due to tumour- or treatment-related factors and may increase mortality risk. Here, we analysed the associations of hypopituitarism, hormone replacement and mortality in a large NFPA cohort derived from two large European centres.

DESIGN, SETTING AND PARTICIPANTS

Case note review of all patients treated for NFPA in University Hospitals Birmingham and Beaumont Hospital Dublin between 1999 and 2014 was performed.

MAIN OUTCOME MEASURES

Clinical presentation, treatment strategies, pituitary function and vitality status were recorded in each patient. A multivariate Cox regression model was used to examine the association between hypopituitarism, hormone replacement and premature mortality.

RESULTS

A total of 519 patients were included in the analysis. Median duration of follow-up was 7·0 years (0·5-43). A total of 81 deaths were recorded (15·6%). On multivariate analysis, adrenocorticotropic hormone (ACTH) and gonadotropin (Gn) deficiencies were associated with an increased relative risk of death (OR 2·26, 95% CI 1·15-4·47, P = 0·01 and OR 2·56, 95% CI 1·10-5·96, P = 0·01, respectively). Increased hydrocortisone (HC) (P-trend = 0·02) and lower levothyroxine (LT4) doses (P-trend = 0·03) were associated with increased risk of death. Mortality increased with the degree of pituitary failure observed (P-trend = 0·04).

CONCLUSION

ACTH and gonadotropin-deficient patients have higher mortality rates compared to those with intact hormonal axes. Excessive HC and suboptimal LT4 replacement may also increase risk of death. Complex associations between hormone deficiency and replacement underpin the increased mortality risk in NFPA patients.

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.

Prevalence and prognosis of a low serum testosterone in men with type 2 diabetes: the Fremantle Diabetes Study Phase II

BACKGROUND

Because published studies have usually involved imprecise assays and selected patients with limited additional data and follow-up, the consequences of a low serum testosterone in diabetes are unclear. This study assessed the prevalence, associates and prognosis of a low testosterone in community-dwelling men with type 2 diabetes.

DESIGN

Longitudinal observational study.

PATIENTS

788 men (mean ± SD age: 65·8 ± 11·3 years) followed for 4·0 ± 1·1 years.

MEASUREMENTS

Serum testosterone, SHBG, erectile dysfunction (ED; Sexual Health Inventory for Men score <22), anaemia (haemoglobin <130 g/l), all-cause mortality.

RESULTS

The mean ± SD total serum testosterone by liquid chromatography/mass spectrometry was 13·1 ± 5·9 nmol/l (30·6% <10 nmol/l). Most men with a total testosterone <10 nmol/l (67·0%) had a normal/low serum LH. Serum testosterone was independently associated with anaemia (P < 0·001), but not ED (P = 0·80), in logistic regression models. The optimal cut-point (Youden Index) for anaemia was 9·8 nmol/l (sensitivity 53·6%, specificity 75·4%). During the follow-up, 102 men (12·9%) died. There was a U-shaped relationship between total serum testosterone quintiles and death (P = 0·003, log rank test). The middle quintile (>11·1 to ≤13·7 nmol/l) had the lowest risk and there was a 78% increased risk for highest (>16·9 nmol/l) vs lowest (≤8·6 nmol/l) quintile in Cox proportional hazards modelling (P = 0·036). Free serum testosterone and SHBG quintiles were not associated with death.

CONCLUSIONS

These data provide some support for the general conventional serum testosterone <10 nmol/l cut-point in identifying an increased risk of anaemia and the subsequent death in men with type 2 diabetes, but indicate that high-normal levels are also an adverse prognostic indicator.

Low-dose testosterone alleviates vascular damage caused by castration in male rats in puberty via modulation of the PI3K/AKT signaling pathway

The aim of the present study was to investigate the effect of testosterone on glucolipid metabolism and vascular injury in male rats, and examine the underlying molecular mechanisms. A total of 40 male Sprague-Dawley rats were divided into a control group (n=10), high-fat-diet + castration group (n=10), high-fat-diet + castration + low dose testosterone group (n=10), and high-fat-diet + castration + high dose testosterone group (n=10). Hematoxylin and eosin staining was performed to evaluate the morphology of the thoracic aortic tissues. Immunohistochemical staining was used to detect biomarkers of the phosphoinositide 3-kinase (PI3K) signaling pathway. The mRNA and protein expression levels of PI3K, AKT, insulin receptor substrate-1 (IRS-1), glucose transporter type 4 (GLUT-4), nuclear factor (NF)-κB and tumor necrosis factor (TNF)-α in the aortas were determined using quantitative polymerase chain reaction and Western blot analyses, respectively. Apoptosis in the aortic tissues was detected using a TUNEL assay. Castration induced apoptosis in the animals fed a high-fat-diet, whereas low dose testosterone replacement ameliorated the apoptosis in the aorta. However, the levels of apoptosis was more severe following high-dose testosterone treatment. Low-dose testosterone induced upregulation in the levels of IRS-1, AKT, GLUT-4 protein, NF-κB, TNF-α and PI3K, compared with those in the animals fed a high-fat diet following castration. A high dose of testosterone resulted in a significant decrease in the levels of IRS-1, AKT, GLUT-4, NF-κB, TNF-α and PI3K. Compared with the rats in the high-fat diet + castration group, a low dose of testosterone induced upregulation in the mRNA levels of IRS-1, AKT and GLUT-4, and downregulation of the mRNA levels of NF-κB, TNF-α and PI3K. A high dose of testosterone resulted in a significant decrease in the levels of IRS-1, AKT and GLUT-4, and marked increases in the mRNA levels of NF-κB, TNF-α and PI3K, compared with the low dose group. Castration induced marked disorders of glucolipid metabolism and vascular injuries in the pubescent male rats. Low-dose testosterone treatment was found to ameliorate the vascular damage caused by castration via the PI3K/AKT signaling pathway.

Men with testosterone deficiency and a history of cardiovascular diseases benefit from long-term testosterone therapy: observational, real-life data from a registry study

Background/objectives

Long-term testosterone therapy (TTh) in men with hypogonadism has been shown to improve all components of the metabolic syndrome. In this study, we investigated the effects of long-term TTh up to 8 years in hypogonadal men with a history of cardiovascular disease (CVD).

Patients and methods

In two urological clinics observational registries, we identified 77 hypogonadal men receiving TTh who also had a history of CVD. The effects of TTh on anthropometric and metabolic parameters were investigated for a maximum duration of 8 years. Any occurrence of major adverse cardiovascular events was reported. All men received long-acting injections of testosterone undecanoate at 3-monthly intervals.

Results

In 77 hypogonadal men with a history of CVD who received TTh, we observed a significant weight loss and a decrease in waist circumference and body mass index. Mean weight decreased from 114±13 kg to 91±9 kg, change from baseline: −24±1 kg and −20.2%±0.5%. Waist circumference decreased from 112±8 cm to 99±6 cm, change from baseline: −13±0.3 cm. Body mass index decreased from 37±4 to 29±3, change from baseline: −8±0.2 kg/m². Cardio-metabolic parameters such as lipid pattern, glycemic control, blood pressure, heart rate, and pulse pressure all improved significantly and sustainably. No patient suffered a major adverse cardiovascular event during the full observation time.

Conclusion

In men with hypogonadism, TTh appears to be effective in achieving sustained improvements in all cardiometabolic risk factors and may be effective as an add-on measure in the secondary prevention of cardiovascular events in hypogonadal men with a history of CVD.

Testosterone and cardiac mass and function in men with type 1 diabetes in the Epidemiology of Diabetes Interventions and Complications Study (EDIC)

OBJECTIVE

Low testosterone concentrations have been reported to be associated with increased risk of congestive heart failure, but the mechanisms are unclear. Our objective was to examine the relationship between endogenous testosterone and measures of cardiac mass and function among men with type 1 diabetes.

DESIGN

Secondary analysis of a prospective observational study.

PARTICIPANTS

Men (n = 508) in the Epidemiology of Diabetes Interventions and Complications (EDIC) study, the observational follow-up of the Diabetes Control and Complications Trial (DCCT).

MEASUREMENTS

Testosterone assessed by liquid chromatography mass spectrometry at EDIC year 10 and cardiac magnetic resonance imaging (CMR) measures at EDIC years 14/15. Linear regression models were used to assess the relationship between testosterone, sex hormone binding globulin (SHBG) and left ventricular (LV) mass, volume, ejection fraction and cardiac index before and after adjustment for age, randomization arm, alcohol and cigarette use, macroalbuminuria, haemoglobin A1c, insulin dose, body mass index, lipids, blood pressure, use of antihypertensive medications and microvascular complications.

RESULTS

In fully adjusted models, total testosterone concentrations were significantly associated with LV mass (P = 0·014), end-diastolic volume (P = 0·002), end-systolic volume (P = 0·012) and stroke volume (P = 0·022), but not measures of LV function after adjustment for cardiac risk factors. Bioavailable testosterone was associated with LV mass, but not volume or function, while SHBG was associated with volume, but not mass or function.

CONCLUSIONS

Among men with type 1 diabetes, higher total testosterone was associated with higher LV mass and volume, but not with function. The clinical significance of this association remains to be established.

Inverse association of total testosterone with central haemodynamics and left ventricular mass in hypertensive men

BACKGROUND

There is evidence for inverse association between endogenous testosterone and blood pressure. Furthermore, low plasma testosterone is associated with increased risk of major cardiovascular events in middle-aged hypertensive men. Central (aortic) blood pressures determine left ventricular hypertrophy and predict cardiovascular mortality. The aim of the present study was to assess the relationship of total testosterone (TT) with central haemodynamics and left ventricular mass in hypertensive men.

METHODS

We investigated 134 non-diabetic, middle-aged, hypertensive men and 60 age-matched normotensive males. All participants were subject to measurement of aortic systolic (aoSBP) and pulse pressure (aoPP) by pulse wave analysis using the SphygmoCor device. Wave reflections were assessed by the measurement of heart rate corrected augmentation index (AIx75). Echocardiography was performed in all individuals and left ventricular mass (LVM) was calculated using the Devereux's formula. Plasma TT was measured by enzyme immunoassay.

RESULTS

In hypertensive men, univariate analysis showed an inverse, significant correlation between TT and aoSBP (r = -20, p = 0.02), aoPP (r = -0.21, p = 0.01), AIx75 (r = -0.22, p = 0.01) and LVM (r = -0.19, p = 0.008). Multivariate regression analysis demonstrated an independent inverse association of TT with aoPP (b = -0.21, p = 0.02), AIx75 (b = -0.19, p = 0.03) and LVM (b = -0.28, p = 0.005) after adjustment for age, BMI, smoking, total cholesterol, triglycerides, fasting glucose, mean arterial pressure, antihypertensive treatment and statin use. Independent associations were retained even after inclusion of normotensive subjects in the analysis.

CONCLUSIONS

In hypertensive men, TT is independently and inversely associated with central pulse pressure, wave reflections and left ventricular mass. Considering the adverse prognostic role of central blood pressures and LV hypertrophy on cardiovascular outcomes in hypertensive patients, the present findings might explain part of the increased cardiovascular risk associated with low testosterone. Whether measurement of central haemodynamics may improve risk stratification in hypertensive men with low testosterone warrants further investigation.

Impact of Testosterone Replacement Therapy on Myocardial Infarction, Stroke, and Death in Men With Low Testosterone Concentrations in an Integrated Health Care System

The aim of this study was to assess the effect of testosterone replacement therapy (TRT) on cardiovascular outcomes. Men (January 1, 1996, to December 31, 2011) with a low initial total testosterone concentration, a subsequent testosterone level, and >3 years of follow-up were studied. Levels were correlated with testosterone supplement use. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of death, nonfatal myocardial infarction, and stroke at 3 years. Multivariate adjusted hazard ratios (HRs) comparing groups of persistent low (<212 ng/dl, n = 801), normal (212 to 742 ng/dl, n = 2,241), and high (>742 ng/dl, n = 1,694) achieved testosterone were calculated by Cox hazard regression. A total of 4,736 men were studied. Three-year rates of MACE and death were 6.6% and 4.3%, respectively. Subjects supplemented to normal testosterone had reduced 3-year MACE (HR 0.74; 95% confidence interval [CI] 0.56 to 0.98, p = 0.04) compared to persistently low testosterone, driven primarily by death (HR 0.65, 95% CI 0.47 to 0.90). HRs for MI and stroke were 0.73 (95% CI 0.40 to 1.34), p = 0.32, and 1.11 (95% CI 0.54 to 2.28), p = 0.78, respectively. MACE was noninferior but not superior for high achieved testosterone with no benefit on MI and a trend to greater stroke risk. In conclusion, in a large general health care population, TRT to normal levels was associated with reduced MACE and death over 3 years but a stroke signal with high achieved levels suggests a conservative approach to TRT.

Testosterone: a hormone preventing cardiovascular disease or a therapy increasing cardiovascular events?

Decreasing testosterone levels with ageing is a well-known condition in older men named 'low T', 'manopause', or hypogonadism. Observational studies suggested an association between low endogenous testosterone levels and a high cardio-metabolic profile (increased blood pressure, dyslipidaemia, insulin resistance, atherosclerosis, thrombosis), as well as a modest increase in total and cardiovascular (CV) mortality. Controversies persist regarding the need for screening 'low T' in older men, as well as what precisely should be the indication(s) for testosterone replacement therapy. So far, no data have shown that normalization of testosterone levels reduce CV events. Although testosterone replacement therapy seems to have beneficial effects on male quality of life or physical condition, some data suggest serious adverse events, such as CV events. In addition, there is a lack of consensus on the threshold for treatment indication in men with non-specific symptoms or borderline levels of testosterone. Available data from clinical practice setting suggest an increase in testosterone prescription over time and possible overtreatment. In recent years, pharmaceutical companies have promoted 'low T' as a treatable disease, suggesting that testosterone replacement may help restore energy, positive mood and sexuality, and despite ageing. Currently, well-designed, adequately powered randomized controlled trials are needed to assess the impact of testosterone replacement therapy on CV clinically relevant CV outcomes within age-specific ranges to strengthen the evidence for clinical practice guidelines.

Could Testosterone Replacement Therapy in Hypogonadal Men Ameliorate Anemia, a Cardiovascular Risk Factor? An Observational, 54-Week Cumulative Registry Study

PURPOSE

In this study we investigated if testosterone undecanoate attenuates anemia and the risk of cardiovascular disease in patients with hypogonadism.

MATERIALS AND METHODS

A registry study consisted of 58 participants with a subnormal total testosterone level (less than 2.35 ng/ml) and at least mild symptoms of testosterone deficiency. All patients received an injection of 1,000 mg testosterone undecanoate at the initial visit, followed by injection at 6, 18, 30, 42 and 54 weeks. Serum hormones, hemoglobin, hematocrit, anemia risk factors, lipid profiles, whole blood viscosity and anthropometry were measured.

RESULTS

Total testosterone (from mean ± SD 1.87 ± 1.09 to 5.52 ± 1.92 ng/ml, p <0.001) and free testosterone (from 3.04 ± 2.03 to 7.23 ± 2.90 pg/ml, p <0.001) were restored by testosterone undecanoate therapy. Hemoglobin and hematocrit significantly increased after testosterone undecanoate therapy by an average of 2.46 gm/dl (p <0.001) and 3.03% (p <0.001), respectively. The prevalence of anemia (from 29.6% to 10.0%) significantly decreased (p <0.001) and patients with anemia showed a significant increase in erythropoietin after testosterone undecanoate therapy (p = 0.047). A reduction in total cholesterol (from 165.89 ± 39.16 to 153.80 ± 154.27 mg/dl, p = 0.002), increased whole blood viscosity and increased hematocrit were observed until 54 weeks compared with baseline. However, whole blood viscosity and hematocrit stabilized after 18 weeks.

CONCLUSIONS

After 54 weeks testosterone undecanoate decreased the prevalence of anemia and components of the metabolic syndrome. A longer duration of testosterone undecanoate therapy of more than 18 weeks may be effective and safe in reducing blood viscosity and improving anemia.