Low testosterone levels are associated with carotid atherosclerosis in men

Cardiovascular disease and testosterone therapy in male hypogonadism

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

Clomiphene Citrate Treatment as an Alternative Therapeutic Approach for Male Hypogonadism: Mechanisms and Clinical Implications

Male hypogonadism, which is characterized by low testosterone levels, has a significant impact on male sexual function, overall health, and fertility. Testosterone replacement therapy (TRT) is the conventional treatment for this condition, but it has potential adverse effects and is not suitable for men seeking to conceive. Testosterone plays an essential role in male sexual function, metabolism, mood, and overall well-being. Clomiphene citrate, a drug originally developed for female infertility, has recently gained attention as an off-label treatment for male hypogonadism. By blocking the negative feedback of estrogen on the hypothalamus and pituitary glands, clomiphene stimulates gonadotropin secretion, leading to increased endogenous testosterone production, which, in turn, improves sperm parameters and fertility and alleviates the symptoms of hypogonadism. Regarding the safety profile of clomiphene compared with TRT, clomiphene appears to confer a lower risk than TRT, which is associated with adverse effects such as polycythemia. Furthermore, combination therapy with clomiphene and anastrozole or human chorionic gonadotropin has been investigated as a potential approach to enhancing the effectiveness of treatments for improving hypogonadism symptoms. In conclusion, clomiphene citrate may offer a promising alternative to TRT for men with hypogonadism, particularly those desiring fertility preservations. However, its long-term efficacy and safety remain inadequately understood. Future research should focus on exploring the benefits of combination therapies and personalized treatment strategies based on individual patient characteristics.

Age-related decrease in serum dihydrotestosterone concentration is accompanied by impaired vascular status

INTRODUCTION

The effect of androgens on the cardiovascular system in humans is ambiguous. Moreover, still little is known about the effects of the most potent androgen, dihydrotestosterone, on arterial stiffness and endothelial function. The aim of this study was to evaluate whether age-dependent alterations in serum concentration of dihydrotestosterone and its circulating metabolite are accompanied by changes in endothelial function and arterial stiffness.

METHODS

In 12 young and 11 older men, basal serum concentrations of testosterone, dehydroepiandrosterone sulfate (DHAE-S), androstenedione (AE), dihydrotestosterone (DHT) and androstanediol glucuronide (ADG) were analyzed in relation to vascular status including cIMT - carotid intima media thickness, cAI - central augmentation index, crPWV - carotid radial pulse wave velocity, SI - stiffness index, endothelial and inflammatory markers.

RESULTS

Although concentration of testosterone was not different between young and older group, it was demonstrated that DHT, DHEA-S, AE and ADG were significantly lower in older men in comparison to young men (p < 0.01). Interestingly the most surprising difference was found for DHT concentration, that was as much as 61 % lower in aged men that displayed significantly higher values of cIMT, AI, crPWV and SI (p < 10^-4), suggestive of arterial stiffness. Furthermore, DHT was negatively correlated to all arterial wall parameters (cAI, crPWV, SI and cIMT), c-reactive protein (CRP) and hyaluronic acid (HA) concentration, as well as positively correlated to markers of endothelial function (MNA and 6-keto-PGF_1α) in all studied individuals (n = 23).

CONCLUSIONS

We have shown that ageing leads to a significant decrease in DHT concentration that is accompanied by impaired arterial wall characteristics and worsened endothelial function. Therefore more attention should be paid to the DHT, DHEA-S and ADG concentrations as a biomarkers for vascular dysfunction in ageing men.

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

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

Relationship between Serum Testosterone Level and Carotid Intima-Media Thickness among Korean Men and Postmenopausal Women

Background

Given that the role of serum testosterone on incident cardiovascular disease has been uncertain, it is necessary to find out the relationship between serum testosterone and carotid atherosclerosis.

Methods

The study participants included 1,302 Korean adults (873 men and 429 postmenopausal women) who participated in the Healthy Twin Study and were not receiving androgen deprivation therapy. The participants were classified into three groups: men aged <40 and ≥40 years and postmenopausal women. Total testosterone (TT) and sex hormone-binding globulin (SHBG) concentrations were measured using electrochemiluminescence immunoassays, and free testosterone (cFT) levels were calculated using Vermeulen’s method. Carotid intima-media thickness (IMT) was measured at three levels using a high-resolution B-mode ultrasound equipped with a 7-MHz linear transducer. The associations between sex hormone concentrations and carotid IMT were evaluated using a mixed linear regression analysis.

Results

After adjusting for cardiovascular risk factors, TT was found to be inversely associated with common carotid IMT in men aged ≥40 years, with a 4.5% decrease in common carotid IMT for every one-standard deviation increase in TT concentration (P=0.0063). In contrast, TT was not significantly associated with carotid IMT in all segments in men aged <40 years and postmenopausal women. Additionally, SHBG and cFT were not associated with carotid IMT in any segment.

Conclusion

The significant association between TT level and common carotid IMT in men aged ≥40 years suggests that decreased testosterone levels are involved in the development of atherosclerosis in men.

Hypertension in Women

Hypertension is one of the main causes of morbidity and mortality in the human population. Nevertheless, the intricate network of pathophysiological mechanisms that lead to the development of hypertension in women still awaits to be fully understood. From young age to maturity and senescence, the female body transits through different stages, each of them characterized with specific physiological features and disposition to particular pathological conditions, and that is exactly what makes the understanding of the genesis and adequate treatment of hypertension in women so challenging. Clinical and experimental findings emphasize the role of sex hormones, autonomic nervous system, renin-angiotensin-aldosterone system and arterial stiffness in the development of chronically elevated blood pressure in females. The purpose of this review is to briefly summarize the knowledge of the mechanisms and treatment of hypertension in women.

Androgenic steroids dysregulation and the risk of coronary artery disease

INTRODUCTION

Endogenous testosterone deficiency or excess anabolic-androgenic steroids (AAS) have been linked to alter the physiology of different organs in the body, more specifically, the vasculature of coronary arteries. Despite the health-related concerns of using synthetic testosterone derivatives, such as AAS, there has been a tremendous increase in the use of AAS among athletes and bodybuilders.

AREAS COVERED

We have highlighted the three main mechanisms that AAS increase the risk of coronary artery disease (CAD): altering the homeostasis of lipid metabolism which results in dyslipidemia and subsequently atherosclerosis, disturbing the function of platelet which results in platelet aggregation and subsequent thrombosis, and increasing the risk of coronary vasospasm by affecting the physiological function of vascular bed.

EXPERT OPINION

Despite the restriction of AAS in specific clinical conditions such as testosterone deficiency and cancer therapy, many amateurs' athletes misuse the AAS. Although there has been a strong association between the AAS misuse and risk of developing CAD, the more valued approach would be a randomized clinical double-blind trial. The suggested primary endpoint would be an occurrence of adverse cardiovascular events, such as myocardial infarction, cerebrovascular accidents, and death. Increasing awareness of the risk of missing AAS among high-risk groups is imperative.

Associations of endogenous androgens and sex hormone-binding globulin with kidney function and chronic kidney disease

INTRODUCTION

The role of endogenous androgens in kidney function and disease has not been extensively explored in men and women.

RESEARCH DESIGN AND METHODS

We analyzed data from the observational KORA F4 study and its follow-up examination KORA FF4 (median follow-up time 6.5 years) including 1293 men and 650 peri- and postmenopausal women, not using exogenous sex hormones. We examined the associations between endogenous androgens (testosterone [T], dihydrotestosterone [DHT], free T [fT], free DHT [fDHT], and T/DHT), with estimated glomerular filtration rate (eGFR) at baseline and follow-up, prevalent, and incident chronic kidney disease (CKD) adjusting for common CKD risk factors.

RESULTS

At baseline, 73 men (5.7%) and 54 women (8.4%) had prevalent CKD. Cross-sectionally, no significant associations between androgens and kidney function were observed among men. In women, elevated T (β=-1.305, [95% CI -2.290; -0.320]) and fT (β=-1.423, [95% CI -2.449; -0.397]) were associated with lower eGFR. Prospectively, 81 men (8.8%) and 60 women (15.2%) developed incident CKD. In women, a reverse J-shaped associations was observed between DHT and incident CKD (P_non-linear=0.029), while higher fDHT was associated with lower incident CKD risk (odds ratio per 1 standard deviation=0.613, [95% CI 0.369; 0.971]. Among men, T/DHT (β=-0.819, [95% CI -1.413; -0.226]) and SHBG (P_non-linear=0.011) were associated with eGFR at follow-up but not with incident CKD. Some associations appeared to be modified by type 2 diabetes (T2D).

CONCLUSION

Suggestive associations are observed of androgens and SHBG with kidney impairment among men and women. However, larger well-phenotyped prospective studies are required to further elucidate the potential of androgens, SHBG, and T2D as modifiable risk factors for kidney function and CKD.

Is there an increased cardiovascular risk in patients with prolactinoma? A challenging question

PURPOSE

Epicardial adipose tissue thickness (EATT) is considered to be a surrogate for visceral fat and a novel cardiovascular risk indicator. Hyperprolactinemia has been shown to be associated with increased cardiovascular risk. The aim was to evaluate the association between EATT, carotid intima media thickness (CIMT), and cardiac functions in patients with prolactinoma.

METHODS

Patients with the diagnosis of prolactinoma were included. The control group consisted of healthy age matched individuals with normal prolactin levels. Prolactin, fasting blood glucose (FBG), insulin, hemoglobin A1c (HbA1c), alanine aminotransferase (ALT), total cholesterol, triglycerides, and high (HDL) and low density lipoprotein (LDL) cholesterol were measured. EATT, CIMT, cardiac systolic, and diastolic functions were determined using echocardiography.

RESULTS

We evaluated 67 patients with prolactinoma (aged 40.7 ± 11.9 years, F/M: 51/16) and 57 controls (aged 42.5 ± 7.4 years, F/M: 36/21). Of the 67 patients, 24 had normal prolactin levels. FBG level was higher in prolactinoma patients than in controls. Patients and controls had similar HbA1c, HOMA-IR, ALT, total, HDL, LDL cholesterol, and triglycerides levels, and similar cardiac systolic and diastolic functions. Prolactinoma patients had greater EATT (3.0 ± 0.5 mm vs. 2.6 ± 0.4 mm, p < 0.001) and CIMT (0.57 ± 0.08 mm vs. 0.52 ± 0.04 mm, p = 0.03) than controls. EATT was correlated with body mass index, FBG, HbA1c, and triglyceride levels.

CONCLUSIONS

EATT and CIMT were greater in patients with prolactinoma, although they had normal cardiac systolic and diastolic functions.

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

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

Vulnerable Plaque Is More Prevalent in Male Individuals at High Risk of Stroke: A Propensity Score-Matched Study

OBJECTIVES

To assess the gender differences in the prevalence of carotid vulnerable plaques in high-risk individuals for stroke in a multicenter, cross-sectional study.

METHODS

In the year 2015, 18595 residents who were at the age of 40 or older participated in a face-to-face study in eight communities in southwestern China. Totally 2,644 participants at high risk of stroke were enrolled. Before and after propensity score matching (PSM), the prevalence of carotid plaques and vulnerable plaques were compared between men and women. Multivariate analyses were applied to explore the association between the gender and carotid plaques. Stratified analyses and interaction tests were performed to identify factors that might modify the association between the gender and carotid plaques.

RESULTS

Among 2644 high-risk individuals enrolled, there were 1,202 (45.5%) men and 1442 (54.5%) women. Carotid plaques were detected in 904 (34.2%) participants, while vulnerable plaques were found in 425 (16.1%) participants. Before PSM, carotid plaques were more prevalent in male individuals than the female (36.7% vs. 32.1%, p = 0.01), as well as vulnerable plaque (20.0% vs. 12.8%, p < 0.01). Men tend to have a higher prevalence of vulnerable plaques in multivariate analyses (adjusted OR 1.70, 95% CI 1.10-2.62, p = 0.02). Stratified analyses and interaction tests demonstrated that the association between male sex and vulnerable carotid plaque did not change by age, family history of stroke, histories of chronic disease, smoking status, drinking status, physical activity, and BMI (all p for interaction > 0.05). After PSM, vulnerable plaques were still more prevalent in male individuals than the female (17.03% vs. 12.07%, p = 0.032).

CONCLUSION

Male individuals had a higher risk of vulnerable carotid plaque independent of classical vascular risk factors. Whether there is a gender-specific association between variations in genes related to inflammation, lipid metabolis, and endothelial function and plaque vulnerability needs to be further studied.

Lowered Serum Testosterone Concentration Is Associated With Enhanced Inflammation and Worsened Lipid Profile in Men

The negative relationship between testosterone and inflammatory cytokines has been reported for decades, although the exact mechanisms of their interactions are still not clear. At the same time, little is known about the relation between androgens and acute phase proteins. Therefore, in this investigation, we aimed to study the relationship between androgen status and inflammatory acute phase reactants in a group of men using multi-linear regression analysis. Venous blood samples were taken from 149 men ranging in age from 18 to 77 years. Gonadal androgens [testosterone (T) and free testosterone (fT)], acute phase reactants [C-reactive protein (CRP), ferritin (FER), alpha-1-acid glycoprotein (AAG), and interleukin-6 (IL-6)], cortisol (C), and lipid profile concentrations were determined. It was demonstrated that the markers of T and fT were negatively correlated with all acute phase proteins (CRP, FER, and AAG; p < 0.02) and the blood lipid profile [total cholesterol (TC), low-density lipoprotein (LDL), and triglycerides (TG); p < 0.03]. Multivariate analysis showed that T, fT, and the fT/C ratio were inversely correlated with the CRP, AAG, and FER concentrations independently of age and blood lipids. When adjustment for BMI was made, T, fT, and the fT/C ratio were negatively correlated with the AAG concentrations only. In addition, it was demonstrated that gonadal androgens were positively correlated with physical activity level (p < 0.01). We have concluded that a lowered serum T concentration may promote inflammatory processes independently of adipose tissue and age through a reduced inhibition of inflammatory cytokine synthesis, which leads to enhanced acute phase protein production. Therefore, a low serum T concentration appears to be an independent risk factor in the development of atherosclerosis and cardiovascular diseases. Moreover, the positive correlation between testosterone and physical activity level suggests that exercise training attenuates the age-related decrease in gonadal androgens and, in this way, may reduce the enhancement of systemic low-grade inflammation in aging men.

Testosterone Therapy and Cardiovascular Risk: A Critical Analysis of Studies Reporting Increased Risk

BACKGROUND

Treatment of "adult-onset hypogonadism" (AOH) with exogenous testosterone therapy (TTh) to raise serum testosterone (T) levels may influence cardiovascular (CV) risk factors in patients with AOH, whereas low endogenous T levels are associated with an increased CV risk and mortality.

AIM

To critically evaluate studies reporting increased CV risk associated with TTh and to provide an overview of the risks and benefits of restoring T levels through exogenous TTh.

METHODS

A review of publications focusing on the association between TTh and increased CV risk was conducted, and the study methodologies and conclusions of each were critically evaluated. Further, recent clinical and epidemiological studies associating AOH or TTh with a change in CV risk, and pertinent hematologic and vascular effects noted in animal studies and in vitro, as well as in clinical practice were also reviewed.

OUTCOMES

A review of the literature shows that untreated testosterone deficiency and/or low T is associated with an increase in CV risk and adverse outcomes, with numerous studies and meta-analyses to support a positive association between exogenous TTh and an improvement in CV risk factors in men with AOH.

RESULTS

Numerous studies in the literature demonstrate the positive benefits of using TTh; however, since 2013, some publications have suggested a link to increased CV risk associated with TTh. A number of these studies retrospectively analyzed insurance claims databases using diagnosis codes, procedures codes, and prescription information. Many reviews published since have pointed out the methodological flaws and debatable conclusions of these studies.

CLINICAL IMPLICATIONS

A careful assessment of the patient's current health status and CV risk factors should be weighed against the benefits and possible risks resulting from TTh, and consideration should be given to deferring treatment pending resolution or stabilization of CV disease or risk factors.

STRENGTHS & LIMITATIONS

In this review, we provide an in-depth analysis of studies reporting increased CV risk with TTh. Many of the studies were not well-designed, randomized, double-blind, prospective clinical trials but rather post hoc analyses of cohort data. These studies may reflect bias in how treatment and nontreatment decisions are made or reflect conclusions based on widely cited methodological flaws.

CONCLUSION

Appropriate patient selection supported by low pre-treatment T levels and monitoring T levels during treatment with the goal of achieving and maintaining physiologic levels all contribute to the safe and effective use of TTh in men with AOH. Khera M, Miner M, Jaffe J, et al. Testosterone Therapy and Cardiovascular Risk: A Critical Analysis of Studies Reporting Increased Risk. J Sex med 2021;18:83-98.

Male childlessness as independent predictor of risk of cardiovascular and all-cause mortality: A population-based cohort study with more than 30 years follow-up

In a recent population-based study, an elevated risk of the Metabolic syndrome (MetS) and type 2 diabetes was found in childless men compared to those who have fathered one or more children. Therefore, by using a larger cohort of more than 22 000 men from the Malmo Preventive Project (MPP) we aimed to expand our observations in order to evaluate the metabolic profile of childless men and to evaluate if childlessness is an additional and independent predictor of major adverse cardiovascular events (MACE), mortality and incident diabetes when accounting for well-known biochemical, anthropometric, socio-economic and lifestyle related known risk factors. Logistic regression was used to assess risk of MACE, diabetes and MetS at baseline. Multivariate Cox regression was used to evaluate the risks of MACE and mortality following the men from baseline screening until first episode of MACE, death from other causes, emigration, or end of follow-up (31^st December 2016) adjusting for age, family history, marital status, smoking, alcohol consumption, educational status, body mass index, prevalent diabetes, high blood lipids, increased fasting glucose and hypertension. Childless men presented with a worse metabolic profile than fathers at the baseline examination, with elevated risk of high triglycerides, odds ratio (OR) 1.24 (95%CI: 1.10–1.42), high fasting glucose OR 1.23 (95%CI: 1.05–1.43) and high blood pressure, OR 1.28 (95%CI: 1.14–1.45), respectively. In the fully adjusted prospective analysis, childless men presented with elevated risk of cardiovascular mortality, HR: 1.33 (95% CI: 1.18–1.49) and all-cause mortality, HR 1.23 (95%CI: 1.14–1.33), respectively. In conclusion, these results add to previous studies showing associations between male reproductive health, morbidity and mortality. Male childlessness, independently of well-known socio-economic, behavioral and metabolic risk factors, predicts risk of cardiovascular disease and mortality. Consequently, this group of men should be considered as target population for preventive measures.

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.

The Effects of Androgens on Cardiometabolic Syndrome: Current Therapeutic Concepts

INTRODUCTION

Cardiometabolic syndrome (CMS), as a bunch of metabolic disorders mainly characterized by type 2 diabetes mellitus (T2DM), hypertension, atherosclerosis, central adiposity, and abdominal obesity triggering androgen deficiency, is one of the most critical threats to men. Although many significant preclinical and clinical findings explain CMS, new approaches toward common pathophysiological mechanisms and reasonable therapeutic targets are lacking.

AIM

To gain a further understanding of the role of androgen levels in various facets of CMS such as the constellation of cardiometabolic risk factors including central adiposity, dyslipidemia, insulin resistance, diabetes, and arterial hypertension and to define future directions for development of effective therapeutic modalities.

METHODS

Clinical and experimental data were searched through scientific literature databases (PubMed) from 2009 to October 2019.

MAIN OUTCOME MEASURE

Evidence from basic and clinical research was gathered with regard to the causal impact and therapeutic roles of androgens on CMS.

RESULTS

There are important mechanisms implicated in androgen levels and the risk of CMS. Low testosterone levels have many signs and symptoms on cardiometabolic and glycometabolic risks as well as abdominal obesity in men.

CLINICAL IMPLICATIONS

The implications of the findings can shed light on future improvements in androgen levels and add potentially predictive risk for CMS, as well as T2DM, abdominal obesity to guide clinical management in the early stage.

STRENGTHS & LIMITATIONS

This comprehensive review refers to the association between androgens and cardiovascular health. A limitation of this study is the lack of large, prospective population-based studies that analyze the effects of testosterone treatment on CMS or mortality.

CONCLUSION

Low testosterone levels have several common features with metabolic syndrome. Thus, testosterone may have preventive role in the progress of metabolic syndrome and subsequent T2DM, abdominal obesity, and cardiovascular disease and likely affect aging men's health mainly through endocrine and vascular mechanisms. Further studies are necessary to evaluate the therapeutic interventions directed at preventing CMS in men. Kirlangic OF, Yilmaz-Oral D, Kaya-Sezginer E, et al. The Effects of Androgens on Cardiometabolic Syndrome: Current Therapeutic Concepts. Sex Med 2020;8:132-155.

Vascular mechanisms of testosterone: The non-genomic point of view

Testosterone (T) is the predominant endogenous androgen in the bloodstream. At the vascular level, T presents genomic and non-genomic effects, and both effects may overlap. The genomic actions assume that androgens can freely cross the plasma membrane of target cells and bind to nuclear androgen receptors, inducing gene transcription and protein synthesis. The non-genomic effects have a more rapid onset and may be related to the interaction with protein/receptor/ion channels of the plasma membrane. The key T effect at the vascular level is vasorelaxation, which is primarily due to its rapid effect. Thus, the main purpose of this review is to discuss the T non-genomic effects at the vascular level and the molecular pathways involved in its vasodilator effect observed in in vivo and in vitro studies. In this sense, the nuclear receptor activation, the influence of vascular endothelium and the activation or inhibition of ion channels (potassium and calcium channels, respectively) will be reviewed regarding all the data that corroborated or not. Moreover, this review also provides a brief update on the association of T with the risk factors for cardiovascular diseases, namely metabolic syndrome, type 2 diabetes mellitus, obesity, atherosclerosis, dyslipidaemia, and hypertension. In summary, in this paper we consider the non-genomic vascular mode of action of androgen in physiological conditions and the main risk factors for cardiovascular diseases.

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.

Is androgen deprivation therapy for prostate cancer associated with cardiovascular disease? A meta-analysis and systematic review

BACKGROUND

Androgen deprivation therapy (ADT) is widely being applied in men who suffered from prostate cancer. Whether androgen deprivation therapy (ADT) is associated with an increased risk of developing cardiovascular-related disease is poorly defined.

OBJECTIVES

The aim of the present meta-analysis is to explore the relationship between ADT and the risk of cardiac events. MATERIALS AND METHODS: For this systematic review and meta-analysis, we searched databases from inception to April 2019 for randomized controlled trials (RCT) or observational studies that reported data on ADT administration and cardiac event incidence. The connection was evaluated through estimating relative risk ratio (RR) and 95% confidence intervals (CIs).

RESULTS

A significantly increased acute myocardial infarction (AMI) was detected in the ADT group compared with the control group (RR = 1.19, 95% confidence interval (CI), 1.02-1.39, P < .05). A significant difference between cardiovascular disease (CVD) and ADT was also observed, with summary RR = 1.25, 95% CI, 1.11-1.40, P < .05. Furthermore, our study also suggested ADT was not related to increased incidence of sudden cardiac death (SCD) (RR = 1.13, 95% CI, 0.92-1.38, P = .24); AMI and CVD were not connected with the duration of ADT (AMI: RR = 1.31; 95% CI, 0.66-2.63, P = .44, for > 5 year group; CVD: RR = 1.12, 95% CI, 0.97-1.30, P = .12, for > 5 year group). In addition, the RR for risk of CVD was 1.28 (95% CI, 1.01-1.62, P < .05) for men with PCa on new hormonal agents.

DISCUSSION

Various ADT modalities have different impact on cardiovascular disease risk in different level. Long-term application of ADT is not associated with increased risk of AMI and CVD. Both abiraterone and enzalutamide could significantly increase the incidence of cardiac events in patients who suffered from prostate cancer. Cautions and periodic cardiovascular elevation are necessary for patients before the ADT starting.

CONCLUSIONS

Androgen deprivation therapy is associated with increased risk of AMI, CHD, in contrast, this association is not detected in SCD.

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 the Heart

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

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.

Effects of testosterone and progressive resistance exercise on vascular function in older men

The cardiovascular effects of testosterone (T) are controversial. Low T has been associated with accelerated vascular aging, characterized by large elastic artery stiffening (decreased compliance), intimal-medial thickening (IMT), and endothelial dysfunction. Endurance exercise improves vascular function, but resistance training may increase arterial stiffness. We sought to determine whether T supplementation improved markers of vascular aging in men with low-normal T and whether T supplementation prevented arterial stiffness with resistance exercise. We studied 160 community-dwelling older men (66 ± 5 yr) with low-normal baseline total T levels (200-350 ng/dl). Participants were randomized to transdermal T gel targeting either a lower (400-550 ng/dl) or higher (600-1,000 ng/dl) T range or to placebo gel and to either progressive resistance training (PRT) or to no exercise for 12 mo. Carotid artery stiffness (arterial compliance) and carotid IMT were measured at baseline, 6 mo, and 12 mo. Endothelial function (brachial artery flow-mediated dilation) was measured in a subset (n = 86). Changes in carotid artery compliance, IMT, and endothelial function with either the lower or higher range of T supplementation were not different from placebo at 6 or 12 mo. There were no differences between PRT and no PRT groups, alone or with T supplementation, in changes in any of the vascular measures at either time point. Supplementation of T and PRT in older men with low-normal levels do not appear to improve or harm vascular function.NEW & NOTEWORTHY Increased promotion and prescription of testosterone (T) to aging men has raised concerns about potential adverse cardiovascular effects. We show that in older men with T levels in the low-normal range, 12 mo of T supplementation with or without resistance exercise did not improve or harm vascular function.

Role of androgens in cardiovascular pathology

Cardiovascular effects of android hormones in normal and pathological conditions can lead to either positive or negative effects. The reason for this variation is unknown, but may be influenced by gender-specific effects of androids, heterogeneity of the vascular endothelium, differential expression of the androgen receptor in endothelial cells (ECs) and route of androgen administration. Generally, androgenic hormones are beneficial for ECs because these hormones induce nitric oxide production, proliferation, motility, and growth of ECs and inhibit inflammatory activation and induction of procoagulant, and adhesive properties in ECs. This indeed prevents endothelial dysfunction, an essential initial step in the development of vascular pathologies, including atherosclerosis. However, androgens can also activate endothelial production of some vasoconstrictors, which can have detrimental effects on the vascular endothelium. Androgens also activate proliferation, migration, and recruitment of endothelial progenitor cells (EPCs), thereby contributing to vascular repair and restoration of the endothelial layer. In this paper, we consider effects of androgen hormones on EC and EPC function in physiological and pathological conditions.

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 Cardiovascular Health

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

Benefits and Health Implications of Testosterone Therapy in Men With Testosterone Deficiency

INTRODUCTION

Testosterone (T) deficiency (TD; hypogonadism) has deleterious effects on men's health; negatively affects glycometabolic and cardiometabolic functions, body composition, and bone mineral density; contributes to anemia and sexual dysfunction; and lowers quality of life. T therapy (TTh) has been used for the past 8 decades to treat TD, with positive effects on signs and symptoms of TD.

AIM

To summarize the health benefits of TTh in men with TD.

METHODS

A comprehensive literature search was carried out using PubMed, articles relevant to TTh were accessed and evaluated, and a comprehensive summary was synthesized.

MAIN OUTCOME MEASURES

Improvements in signs and symptoms of TD reported in observational studies, registries, clinical trials, and meta-analyses were reviewed and summarized.

RESULTS

A large body of evidence provides significant valuable information pertaining to the therapeutic value of TTh in men with TD. TTh in men with TD provides real health benefits for bone mineral density, anemia, sexual function, glycometabolic and cardiometabolic function, and improvements in body composition, anthropometric parameters, and quality of life.

CONCLUSION

TTh in the physiologic range for men with TD is a safe and effective therapeutic modality and imparts great benefits on men's health and quality of life. Traish AM. Benefits and Health Implications of Testosterone Therapy in Men With Testosterone Deficiency. Sex Med Rev 2018;6:86-105.

Genomic and non-genomic effects of androgens in the cardiovascular system: clinical implications

The principle steroidal androgens are testosterone and its metabolite 5α-dihydrotestosterone (DHT), which is converted from testosterone by the enzyme 5α-reductase. Through the classic pathway with androgens crossing the plasma membrane and binding to the androgen receptor (AR) or via mechanisms independent of the ligand-dependent transactivation function of nuclear receptors, testosterone induces genomic and non-genomic effects respectively. AR is widely distributed in several tissues, including vascular endothelial and smooth muscle cells. Androgens are essential for many developmental and physiological processes, especially in male reproductive tissues. It is now clear that androgens have multiple actions besides sex differentiation and sexual maturation and that many physiological systems are influenced by androgens, including regulation of cardiovascular function [nitric oxide (NO) release, Ca²⁺ mobilization, vascular apoptosis, hypertrophy, calcification, senescence and reactive oxygen species (ROS) generation]. This review focuses on evidence indicating that interplay between genomic and non-genomic actions of testosterone may influence cardiovascular function.

Association of admission testosterone level with ST-segment resolution in male patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background

Low level of testosterone may be associated with cardiovascular diseases in men, as some evidence suggests a protective role for testosterone in cardiovascular system. Little is known about the possible role of serum testosterone in response to reperfusion therapy in ST-elevation myocardial infarction (STEMI) and its relationship with ST-segment recovery. The present study was conducted to evaluate the association of serum testosterone levels with ST-segment resolution following primary percutaneous coronary intervention (PPCI) in male patients with acute STEMI.

Methods

Forty-eight men (mean age 54.55 ± 12.20) with STEMI undergoing PPCI were enrolled prospectively. Single-lead ST segment resolution in the lead with maximum baseline ST-elevation was measured and patients were divided into two groups according to the degree of ST-segment resolution: complete (> or =50%) or incomplete (<50%). The basic and demographic data of all patients, their left ventricular ejection fraction (LVEF) and laboratory findings including serum levels of free testosterone and cardiac enzymes were recorded along with angiographic finding and baseline TIMI (Thrombolysis in Myocardial Infarction) flow and also in-hospital complications and then these variables were compared between two groups.

Results

A complete ST-resolution (≥50%) was observed in 72.9% of the patients. The serum levels of free testosterone (P = 0.04), peak cardiac troponin (P = 0.03) were significantly higher and hs-CRP (P = 0.02) were lower in patients with complete ST-resolution compared to those with incomplete ST-resolution. In-hospital complications were observed in 31.2% of patients. The patients with a lower baseline TIMI flow (P = 0.03) and those who developed complications (P = 0.04) had lower levels of free testosterone. A significant positive correlation was observed between the left ventricular function and serum levels of free testosterone (P = 0.01 and r = +0.362).

Conclusion

This study suggests that in men with STEMI undergoing PPCI, higher serum levels of testosterone are associated with a better reperfusion response, fewer complications and a better left ventricular function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12610-017-0058-7) contains supplementary material, which is available to authorized users.

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.

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.

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

AIM

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Associations of Cardiovascular Risk Factors with Carotid Intima-Media Thickness in Middle-Age Adults and Elders

Aims: Elevated carotid intima-media thickness (cIMT) is a preclinical phenotype of atherosclerotic diseases. There are significant sex differences in the morbidities of cardiovascular diseases and their major determinants, and we explored the sex-specific effects of cardiovascular factors on cIMT by a community-based study.

Methods: We measured the cIMT and cardiovascular profiles of 1579 residents aged 40–74 years in northern Taiwan. Multivariate regression analyses were used to assess the effects and contributions of these factors on cIMT.

Results: Males had significantly higher mean (± SD) of cIMT than females (0.668 ± 0.113 vs. 0.632 ± 0.100 nm, p < 0.0001). The common factors of the best-fit regression models in both sexes were age, BMI, and LDL-/HDL-C ratio; however, their contributions and effects were different. The partial coefficients of determination (r²) were 17.9, 5.8, and 4.1%, respectively, for males and were 27.8, 1.4, and 1.2%, respectively, for females. Test statistics showed that the regression coefficients of BMI and LDL-/HDL-C ratio of males were significantly higher than those of females. As compared with females, per 1.0 SD increases of BMI and LDL-/HDL-C in males resulted in 0.0971 (p = 0.030) and 0.1177 (p = 0.0087), respectively, SD increases in cIMT. There was no difference in the means of cIMT between pre- and post-menopausal women of the same age groups.

Conclusions: There was a significant sex difference in cIMT. The contributions and effects of LDL-/HDL-C ratio and BMI on cIMT were more profound in males. Our findings indicate that sex-specific factors, but possibly not menstrual status-related factors, contribute to thicker cIMT.

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.

A Comparative Study of Lipid Profile and Cardiovascular Risk Biomarkers Among Chronic Haemodialysis Patients and Healthy Individuals

INTRODUCTION

Lipid abnormalities and increase in inflammatory markers are common among patients with End Stage Renal Disease (ESRD) and it tends to persist/worsen even after initiating Intermittent Haemodialysis (IHD). The cardiovascular mortality and morbidity remains significantly high in this population.

AIM

The present study was carried out to assess the pattern of lipid abnormality in our population and to find its association with inflammatory markers.

MATERIALS AND METHODS

It was a cross-sectional, observational study on ESRD patients undergoing Haemodialysis (HD) in comparison with age and sex matched healthy individuals in a tertiary care hospital. About 40 adult male and female patients aged >18 years, undergoing chronic HD for more than 6 months were enrolled in Group A. Patients who were alcoholics, tobacco consumers and those on steroids and hypolipidemic drugs were excluded. Group B consisted of healthy, age and sex matched controls. Serum lipid profile, lipoprotein A, apolipoprotein A1, apolipoprotein B and apo B/A1 ratio, serum uric acid, homocysteine, hs-CRP and testosterone levels were estimated among patients undergoing intermittent HD and healthy individuals. Chi-square/Fisher's-exact test was used for comparing ratios. A p-value of <0.05 was considered statistically significant.

RESULTS

The mean Total Cholesterol (TC), Low Density Lipoprotein (LDL) and Non-HDL High Density Lipoprotein cholesterol was significantly lower in HD patients as compared to control group with all the three parameters attaining statistical significance (p<0.005). The mean lipoprotein A level was significantly higher (p=0.037), while Apo A1 was found to be significantly lower (p=0.001) in patients receiving HD. Inflammatory markers like uric acid was high (p<0.005) and serum testotsterone level in male HD patient was significantly low (p<0.005).

CONCLUSION

The mean values of traditional serum lipid profile remained lower in HD patients than the control group. The abnormalities in lipoprotein A and apolipoproteins were more pronounced in patients undergoing HD. The mean level of testosterone also was found to be lower in male patients receiving HD. Hence, estimation of lipoprotein A, apolipoproteins and inflammatory markers may serve as a potential tool in cardiovascular risk stratification.

Androgen actions on endothelium functions and cardiovascular diseases

The roles of androgens on cardiovascular physiology and pathophysiology are controversial as both beneficial and detrimental effects have been reported. Although the reasons for this discrepancy are unclear, multiple factors such as genetic and epigenetic variation, sex-specificity, hormone interactions, drug preparation and route of administration may contribute. Recently, growing evidence suggests that androgens exhibit beneficial effects on cardiovascular function though the mechanism remains to be elucidated. Endothelial cells (ECs) which line the interior surface of blood vessels are distributed throughout the circulatory system, and play a crucial role in cardiovascular function. Endothelial progenitor cells (EPCs) are considered an indispensable element for the reconstitution and maintenance of an intact endothelial layer. Endothelial dysfunction is regarded as an initiating step in development of atherosclerosis and cardiovascular diseases. The modulation of endothelial functions by androgens through either genomic or nongenomic signal pathways is one possible mechanism by which androgens act on the cardiovascular system. Obtaining insight into the mechanisms by which androgens affect EC and EPC functions will allow us to determine whether androgens possess beneficial effects on the cardiovascular system. This in turn may be critical in the prevention and therapy of cardiovascular diseases. This article seeks to review recent progress in androgen regulation of endothelial function, the sex-specificity of androgen actions, and its clinical applications in the cardiovascular system.

Association of endogenous testosterone with subclinical atherosclerosis in men: the multi-ethnic study of atherosclerosis

OBJECTIVES

Whether endogenous sex hormones play a role in cardiovascular disease (CVD) risk in men is unclear. Few studies have examined associations of sex hormones with atherosclerosis measured by coronary artery calcium score (CACS) and carotid intima-media thickness (cIMT). We evaluated the association of testosterone (T) and other sex hormones with CACS and cIMT.

METHODS

Using the large multi-ethnic cohort of 3164 men without known CVD in the Multi-Ethnic Study of Atherosclerosis (MESA), cross-sectional associations of tertiles of endogenous sex hormones with CACS and cIMT were analysed.

RESULTS

In regard to CAC, there was a significant negative trend (P-trend = 0·02) for CACS>0 over tertiles of free T (FT) with RRs (95% CI) for the lowest to highest tertiles. There was also a marginally significant positive trend (P-trend = 0·06) for CACS>0 over tertiles of sex hormone-binding globulin (SHBG) with RRs for the lowest to highest tertiles. There were no significant associations with CACS >0 for tertiles of TT (Total T), bioavailable T (BT), oestradiol (E2) and dehydroepiandrosterone (DHEA). There was significantly higher log CACS after adjustment for CVD risk factors for lower TT levels, compared to higher levels, using 9·54 and 10·4 nmol/l as cut-off points. In regard to cIMT, there was a significant positive trend (P = 0·003) in mean cIMT over the tertiles of BT, but not for TT, FT, E2, DHEA and SHBG. There was significantly lower cIMT after adjustment for CVD risk factors for lower TT levels compared to higher levels.

CONCLUSION

In a population of male subjects with no known CVD, lower FT is associated with higher RR of CACS>0 and lower TT is associated with higher log CACS. Lower BT and TT are associated with lower cIMT. While these findings support the positive correlation between low T and coronary atherosclerosis, the opposite findings on cIMT warrant further evaluation.

Androgen receptor (AR) in cardiovascular diseases

Cardiovascular diseases (CVDs) are still the highest leading cause of death worldwide. Several risk factors have been linked to CVDs, including smoking, diabetes, hyperlipidemia, and gender among others. Sex hormones, especially the androgen and its receptor, androgen receptor (AR), have been linked to many diseases with a clear gender difference. Here, we summarize the effects of androgen/AR on CVDs, including hypertension, stroke, atherosclerosis, abdominal aortic aneurysm (AAA), myocardial hypertrophy, and heart failure, as well as the metabolic syndrome/diabetes and their impacts on CVDs. Androgen/AR signaling exacerbates hypertension, and anti-androgens may suppress hypertension. Androgen/AR signaling plays dual roles in strokes, depending on different kinds of factors; however, generally males have a higher incidence of strokes than females. Androgen and AR differentially modulate atherosclerosis. Androgen deficiency causes elevated lipid accumulation to enhance atherosclerosis; however, targeting AR in selective cells without altering serum androgen levels would suppress atherosclerosis progression. Androgen/AR signaling is crucial in AAA development and progression, and targeting androgen/AR profoundly restricts AAA progression. Men have increased cardiac hypertrophy compared with age-matched women that may be due to androgens. Finally, androgen/AR plays important roles in contributing to obesity and insulin/leptin resistance to increase the metabolic syndrome.

Serum androgen concentrations and subclinical measures of cardiovascular disease in men and women

OBJECTIVES

Most of the observed associations of androgens and sex hormone-binding globulin (SHBG) with subclinical cardiovascular disease (CVD) stem from selected study samples with immunoassay-based hormone measurements. Thus, we used a large population-based sample with total testosterone (TT) and androstenedione (ASD) concentrations measured by liquid chromatography-tandem mass spectrometry.

DESIGN

Data of 2140 individuals (mean age: 60,8 years) from the cohort Study of Health in Pomerania were assessed at baseline and 5-year follow-up.

METHODS

Multivariable regression models were implemented to assess cross-sectional and longitudinal associations of TT, free testosterone (fT), ASD, SHBG and dehydroepiandrosterone-sulphate (DHEAS) with measures of subclinical CVD including intima media thickness (IMT), carotid plaques, left ventricular mass (LVM), fractional shortening (FS), relative wall thickness (RWT), and left ventricular geometry.

RESULTS

Cross-sectional analyses yielded an association of TT with IMT in women (β-coefficient per log unit increase: 0.02; 95% CI: 0.007; 0.45) and ASD with FS in both sexes (men: β-coefficient: -2.94; 95% CI: -4.75; -1.12; women: β-coefficient: 1.64; 95% CI: 0.55; 2.73). In longitudinal analyses, DHEAS was positively associated with FS change (β-coefficient: 2.34; 95% CI: -0.59; 4.08). In women, SHBG was positively associated with incident plaques (Q1 vs. Q3 (Ref.): β-coefficient: 1.35; 95% CI: 1.04; 1.74). In both sexes, longitudinal analyses showed no consistent association of TT with subclinical CVD.

CONCLUSIONS

Despite several sex-specific associations of androgens and SHBG with subclinical CVD, the present representative study for the age group ≥45 years among men and women from the general population detected no consistent associations in longitudinal analyses.

Reactive oxygen species: players in the cardiovascular effects of testosterone

Androgens are essential for the development and maintenance of male reproductive tissues and sexual function and for overall health and well being. Testosterone, the predominant and most important androgen, not only affects the male reproductive system, but also influences the activity of many other organs. In the cardiovascular system, the actions of testosterone are still controversial, its effects ranging from protective to deleterious. While early studies showed that testosterone replacement therapy exerted beneficial effects on cardiovascular disease, some recent safety studies point to a positive association between endogenous and supraphysiological levels of androgens/testosterone and cardiovascular disease risk. Among the possible mechanisms involved in the actions of testosterone on the cardiovascular system, indirect actions (changes in the lipid profile, insulin sensitivity, and hemostatic mechanisms, modulation of the sympathetic nervous system and renin-angiotensin-aldosterone system), as well as direct actions (modulatory effects on proinflammatory enzymes, on the generation of reactive oxygen species, nitric oxide bioavailability, and on vasoconstrictor signaling pathways) have been reported. This mini-review focuses on evidence indicating that testosterone has prooxidative actions that may contribute to its deleterious actions in the cardiovascular system. The controversial effects of testosterone on ROS generation and oxidant status, both prooxidant and antioxidant, in the cardiovascular system and in cells and tissues of other systems are reviewed.

The effect of testosterone on cardiovascular risk factors in men with type 2 diabetes and late-onset hypogonadism treated with metformin or glimepiride

BACKGROUND

Men with type 2 diabetes are often characterized by abnormal plasma testosterone levels. This study was aimed at investigating whether testosterone treatment has an impact on cardiovascular risk factors in patients with type 2 diabetes and late-onset hypogonadism (LOH), chronically treated with hypoglycemic agents.

METHODS

This study included 51 men with type 2 diabetes, 26 of whom had already been treated with metformin and 25 with glimepiride for at least 6 months. On the basis of patient preference, 15 men receiving metformin and 12 receiving glimepiride were treated with intramuscular testosterone enanthate (100mg weekly) for 12 weeks. Plasma lipids, glucose homeostasis markers, as well as plasma levels of androgens, uric acid, high-sensitivity C-reactive protein (hsCRP), homocysteine and fibrinogen were determined before and at the end of the study.

RESULTS

With the exception of insulin sensitivity, plasma hsCRP and homocysteine, there were no differences between patients treated with metformin and glimepiride. Testosterone enanthate administered to both groups of patients increased plasma testosterone, reduced plasma hsCRP and improved insulin sensitivity. Testosterone-metformin combination therapy reduced also circulating levels of uric acid, homocysteine and fibrinogen. These effects, stronger in patients treated with metformin than glimepiride, correlated with the impact of testosterone on insulin sensitivity.

CONCLUSIONS

Our results suggest that testosterone may bring more clinical benefits to metformin- than sulfonylurea-treated men with diabetes and LOH.