Low plasma testosterone and elevated carotid intima-media thickness: importance of low-grade inflammation in elderly men

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.

Testosterone and aging male, a perspective from a developing country

PURPOSE

Hypogonadism is associated with a wide range of physical and psychological symptoms that can affect the overall health of men. However, in a developing country, there are several imposing challenges in the diagnosis and treatment of hypogonadism, including a lack of awareness and understanding of the condition among healthcare providers and patients, limited resources and the high cost of treatment. This review aimed to examine the potential benefits and risks of testosterone replacement therapy (TRT) and provides a perspective of a developing country on the topic.

MATERIALS AND METHODS

A comprehensive literature review was conducted to gather relevant information on the impact of testosterone deficiency on ageing males and the effectiveness of TRT for treating hypogonadism. Published peer-reviewed articles were analyzed to evaluate the benefits and risks of TRT. Additionally, the unique challenges faced in the diagnosis and treatment of hypogonadism in a developing country were considered.

RESULTS

Testosterone replacement therapy has been shown to be an effective treatment for hypogonadism, particularly in symptomatic men with low testosterone levels. It offers potential benefits such as improvements in symptoms and overall quality of life. However, there are associated risks and side effects that need to be considered. In a developing country, challenges such as limited awareness and understanding of hypogonadism, resource constraints, and high treatment costs pose additional barriers to accessing TRT and comprehensive care.

CONCLUSION

In conclusion, TRT holds promise as a treatment for hypogonadism, but its implementation and accessibility face significant challenges in a developing country. Addressing these challenges, including raising awareness, allocating resources, and finding cost-effective solutions, is crucial for ensuring that men with hypogonadism in such settings receive appropriate diagnosis and treatment. Further research and efforts are needed to improve the management of hypogonadism in developing countries and optimize the potential benefits of TRT for affected individuals.

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.

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.

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.

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.

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.

Testosterone replacement therapy and cardiovascular risk

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

Testosterone inhibits aneurysm formation and vascular inflammation in male mice

Abdominal aortic aneurysm (AAA), one of the pathological phenotypes of vascular aging, is characterized by aortic dilation with impaired arterial wall integrity. Recent epidemiologic studies have shown that men with AAA have lower serum testosterone compared to men without. However, the underlying mechanisms remain unclear. In this study, we investigated the effects of testosterone on AAA formation using a murine AAA model under the conditions of depletion and administration of testosterone. In wild-type male mice (C57BL/6J), AAA was induced by CaCl2 application and angiotensin II infusion at 5 weeks after castration. Exacerbated AAA formation was seen in castrated mice, compared with sham-operated mice. Histological analysis revealed marked infiltration of macrophages in the destroyed aorta and IL-6/pSTAT3 expression was significantly elevated, suggesting that AAA development by castration is attributable to pronounced inflammation. Conversely, both 4-week and 9-week administration of testosterone significantly prevented AAA formation, and improvement of histological findings was confirmed. Aortic F4/80, Il-1b and Il-6 expression were significantly inhibited both by testosterone administration. Indeed, mice with implanted flutamide exhibited exacerbated AAA formation and aortic F4/80, Il-1b and Il-6 expression were significantly increased. Taken together, these results demonstrate that testosterone depletion and AR blockade precede AAA formation, and conversely, testosterone administration could suppress AAA formation by regulating macrophage-mediated inflammatory responses. This anti-inflammatory action of testosterone/AR on AAA formation might provide a mechanistic insight into the vascular protective actions of testosterone and suggest that its proper administration or selective AR modulators might be novel therapeutic strategies for this aortic pathology.

Testosterone, myocardial function, and mortality

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

Association of appendicular skeletal muscle mass with carotid intima-media thickness according to body mass index in Korean adults

OBJECTIVES

The combined effects of obesity and appendicular skeletal muscle (ASM) on atherosclerosis, especially in middleaged populations, remain poorly understood. This cross-sectional study investigated the effects of ASM on carotid intima-media thickness (IMT) according to body mass index (BMI) in middle-aged Korean adults.

METHODS

Herein, 595 men and 1,274 women aged 30-64 years completed questionnaires and underwent health examinations as part of the Cardiovascular and Metabolic Disease Etiology Research Center cohort. ASM was measured via bioelectrical impedance analysis and adjusted for weight (ASM/Wt). IMT was assessed using B-mode ultrasonography; highest quartile of IMT was defined as gender-specific top quartile of the IMT values. Higher BMIs was defined as a BMI over 25.0 kg/m2 .

RESULTS

Compared to the highest ASM/Wt quartile, the lowest ASM/Wt quartile was significantly associated with highest quartile of IMT in men with lower BMIs (adjusted odds ratio [aOR], 2.78; 95% confidence interval [CI], 1.09 to 7.13), but not in those with higher BMIs (aOR, 0.59; 95% CI, 0.24 to 1.91). In women, there was no significant association of low skeletal muscle mass with highest quartile of IMT, regardless of BMI.

CONCLUSIONS

Low appendicular skeletal muscle mass is associated with carotid arterial wall thickening in men with lower BMIs, but not in men with higher BMIs. Our findings suggest that the risk of atherosclerosis may be low in middle-aged Korean men with appropriate body weight and skeletal muscle mass maintenance.

What does the research say about androgen use and cerebrovascular events?

Many studies have investigated the benefits of androgen therapy and neurosteroids in aging men, while concerns remain about the potential associations of exogenous steroids and incidents of cerebrovascular events and ischemic stroke (IS). Testosterone is neuroprotective, neurotrophic and a potent stimulator of neuroplasticity. These benefits are mediated primarily through conversion of a small amount of testosterone to estradiol by the catalytic activity of estrogen synthetase (aromatase cytochrome P450 enzyme). New studies suggest that abnormal serum levels of the nonaromatized potent metabolite of testosterone, either high or low dihydrotestosterone (DHT), is a risk factor for stroke. Associations between pharmacologic androgen use and the incidence of IS are questionable, because a significant portion of testosterone is converted to DHT. There is also insufficient evidence to reject a causal relationship between the pro-testosterone adrenal androgens and incidence of IS. Moreover, vascular intima-media thickness, which is a predictor of stroke and myocardial symptoms, has correlations with sex hormones. Current diagnostic and treatment criteria for androgen therapy for cerebrovascular complications are unclear. Confounding variables, including genetic and metabolic alterations of the key enzymes of steroidogenesis, ought to be considered. Information extracted from pharmacogenetic testing may aid in expounding the protective-destructive properties of neurosteroids, as well as the prognosis of androgen therapy, in particular their cerebrovascular outcomes. This investigative review article addresses relevant findings of the clinical and experimental investigations of androgen therapy, emphasizes the significance of genetic testing of androgen responsiveness towards individualized therapy in post-IS injuries as well as identifying pertinent questions.

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

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

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.

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.

Low testosterone levels are related to oxidative stress, mitochondrial dysfunction and altered subclinical atherosclerotic markers in type 2 diabetic male patients

INTRODUCTION

Low testosterone levels in men are associated with type 2 diabetes and cardiovascular risk. However, the role of testosterone in mitochondrial function and leukocyte-endothelium interactions is unknown. Our aim was to evaluate the relationship between testosterone levels, metabolic parameters, oxidative stress, mitochondrial function, inflammation and leukocyte-endothelium interactions in type 2 diabetic patients.

MATERIALS AND METHODS

The study was performed in 280 male type 2 diabetic patients and 50 control subjects. Anthropometric and metabolic parameters, testosterone levels, reactive oxygen species (ROS) production, mitochondrial membrane potential, TNFα, adhesion molecules and leukocyte-endothelium cell interactions were evaluated.

RESULTS

Testosterone levels were lower in diabetic patients. Total and mitochondrial ROS were increased and mitochondrial membrane potential, SOD and GSR expression levels were reduced in diabetic patients. TNFα, ICAM-1 and VCAM-1 levels, leukocyte rolling flux and adhesion were all enhanced in diabetic patients, while rolling velocity was reduced. Testosterone levels correlated negatively with glucose, HOMA-IR, HbA1c, triglycerides, nonHDL-c, ApoB, hs-CRP and AIP, and positively with HDL-c and ApoA1. The multivariable regression model showed that HDL-c, HOMA-IR and age were independently associated with testosterone. Furthermore, testosterone levels correlated positively with membrane potential and rolling velocity and negatively with ROS production, VCAM-1, rolling flux and adhesion.

CONCLUSIONS

Our data highlight that low testosterone levels in diabetic men are related to impaired metabolic profile and mitochondrial function and enhanced inflammation and leukocyte-endothelium cell interaction, which leaves said patients at risk of cardiovascular events.

Low-Grade Inflammation and Increased Arterial Stiffness in Chinese Youth and Adolescents with Newly-Diagnosed Type 2 Diabetes Mellitus

OBJECTIVE

To investigate the relationship between low-grade inflammation (LI) and increased arterial stiffness in Chinese youth and adolescents with newly-diagnosed type 2 diabetes mellitus (T2DM).

METHODS

Ninety-eight subjects aged 10 to 24 years with newly-diagnosed T2DM were investigated for findings of general inflammation. Anthropometric measurements were taken. Data related to arterial stiffness [brachial artery distensibility (Branch D), augmentation index (AIx), carotid-femoral pulse wave velocity (CF-PWV)] were collected. The subjects were divided into a non-LI group (NLI, n=42) and a LI group (n=56) according to their high-sensitivity C-reactive protein (Hs-CRP) levels.

RESULTS

There were no significant differences in age and gender between the LI group and the NLI group. CF-PWV and AIx values of the LI group were higher than those of the NLI group (p<0.01), while Branch D values were lower in the LI group (p<0.01). Branch D, CF-PWV, and AIx values correlated significantly with Hs-CRP overall (r=-0.32, 0.34, 0.33, all p<0.01). Multivariate models revealed that in either group (LI or NLI), Hs-CRP, as a continuous variable, was an independent determinant of arterial stiffness parameters even after adjusting for other risk factors.

CONCLUSION

Newly-diagnosed T2DM youth and adolescents with LI present a more adverse cardiovascular disease risk profile and stiffer arteries. Hs-CRP levels correlated with arterial stiffness parameters and constituted an independent determinant of arterial stiffness.

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

CONTEXT

Epidemiologic studies suggest that endogenous testosterone (T) levels in males may be implicated in cardiovascular disease (CVD), however further clarification is needed.

OBJECTIVE

We assessed the cross-sectional relationship between endogenous plasma T and mean carotid intima media thickness (cIMT), and the longitudinal relationship with incident clinical CVD events, cardiac mortality, and all-cause mortality using male participants in the Atherosclerosis Risk in Communities (ARIC) study.

DESIGN

This study involved a subset of men from visit 4 of the ARIC study.

SETTING

The study was conducted in a community based cohort.

PARTICIPANTS

Males who provided a morning blood sample excluding those taking androgen therapy, with prevalent coronary heart disease (CHD), stroke, or heart failure (HF) (n = 1558).

INTERVENTION

None.

MAIN OUTCOME MEASURES

Plasma T by liquid chromatography mass spectrometry and carotid IMT using high resolution B-mode ultrasound were obtained at visit 4. Incident CHD, HF, cardiac mortality, and all-cause mortality were identified by surveillance through 2010 (median 12.8 years).

RESULTS

Lower T was significantly associated with higher body mass index, greater waist circumference, diabetes, hypertension, lower HDL, and never smoking (P = 0.01). T was not associated with mean cIMT in unadjusted or adjusted analyses. Following multivariable adjustment, there was no association of quartile (Q) of T with incident CHD [hazard ratio (HR) = 0.87 (95% CI = 0.60-1.26) for Q1; 0.97 (95% CI = 0.69-1.38) for Q2; 0.97 (95% CI = 0.69-1.36) for Q3 compared to reference of Q4] or for incident HF [HR = 0.77 (95% CI = 0.46-1.29) for Q1; 0.72 (95% CI = 0.43-1.21) for Q2; 0.87 (95% CI = 0.53-1.42) for Q3 compared to reference of Q4]. Similarly there was no association of Q of T with mortality or cardiac-associated mortality.

CONCLUSIONS

Low male plasma T is cross-sectionally associated with key CVD risk factors, but after adjustment there was no association with mean cIMT, incident cardiac events, or mortality. Our results are reassuring that neither high nor low T levels directly predict atherosclerosis, but are a marker for other cardiovascular risk factors.

Testosterone therapy and cardiovascular risk: advances and controversies

Two recent studies raised new concerns regarding cardiovascular (CV) risks with testosterone (T) therapy. This article reviews those studies as well as the extensive literature on T and CV risks. A MEDLINE search was performed for the years 1940 to August 2014 using the following key words: testosterone, androgens, human, male, cardiovascular, stroke, cerebrovascular accident, myocardial infarction, heart attack, death, and mortality. The weight and direction of evidence was evaluated and level of evidence (LOE) assigned. Only 4 articles were identified that suggested increased CV risks with T prescriptions: 2 retrospective analyses with serious methodological limitations, 1 placebo-controlled trial with few major adverse cardiac events, and 1 meta-analysis that included questionable studies and events. In contrast, several dozen studies have reported a beneficial effect of normal T levels on CV risks and mortality. Mortality and incident coronary artery disease are inversely associated with serum T concentrations (LOE IIa), as is severity of coronary artery disease (LOE IIa). Testosterone therapy is associated with reduced obesity, fat mass, and waist circumference (LOE Ib) and also improves glycemic control (LOE IIa). Mortality was reduced with T therapy in 2 retrospective studies. Several RCTs in men with coronary artery disease or heart failure reported improved function in men who received T compared with placebo. The largest meta-analysis to date revealed no increase in CV risks in men who received T and reduced CV risk among those with metabolic disease. In summary, there is no convincing evidence of increased CV risks with T therapy. On the contrary, there appears to be a strong beneficial relationship between normal T and CV health that has not yet been widely appreciated.

The relationship between testosterone, metabolic syndrome, and mean carotid intima-media thickness in aging men

We studied relationships between testosterone, metabolic syndrome, and mean carotid intima-media thickness (IMT) in aging men. We enrolled 935 men who had participated in a health examination. The median age was 57.0 years. Mean IMT showed a significant and negative linear correlation with testosterone (correlation co-efficiency = -0.067, p = 0.039). There was a significant increase in the percentage of men with hypogonadism in the second and third tertiles of mean IMT (p trend = 0.022). Logistic regression revealed a greater likelihood of hypogonadism in the third tertile mean IMT group when compared to the first tertile mean IMT group after adjusting for age and metabolic syndrome (OR = 1.700, p = 0.044). After adjusting for age and testosterone level, mean IMT was significantly higher in metabolic syndrome group as compared to non-metabolic syndrome group (0.733 mm versus 0.764 mm; p < 0.001). Mean testosterone level was significantly lower in metabolic syndrome group as compared to non-metabolic syndrome group after adjusting for age and mean IMT (5.52 ng/mL versus 4.89 ng/mL; p < 0.001). Mean IMT, testosterone, and metabolic syndrome were significantly and independently correlated with each other in aging male. Further studies are needed to confirm our results and to elucidate their causative relationship.

Metabolic effects of testosterone replacement therapy on hypogonadal men with type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials

This systematic review was aimed at assessing the metabolic effects of testosterone replacement therapy (TRT) on hypogonadal men with type 2 diabetes mellitus (T2DM). A literature search was performed using the Cochrane Library, EMBASE and PubMed. Only randomized controlled trials (RCTs) were included in the meta-analysis. Two reviewers retrieved articles and evaluated the study quality using an appropriate scoring method. Outcomes including glucose metabolism, lipid parameters, body fat and blood pressure were pooled using a random effects model and tested for heterogeneity. We used the Cochrane Collaboration's Review Manager 5.2 software for statistical analysis. Five RCTs including 351 participants with a mean follow-up time of 6.5-months were identified that strictly met our eligibility criteria. A meta-analysis of the extractable data showed that testosterone reduced fasting plasma glucose levels (mean difference (MD): −1.10; 95% confidence interval (CI) (−1.88, −0.31)), fasting serum insulin levels (MD: −2.73; 95% CI (−3.62, −1.84)), HbA1c % (MD: −0.87; 95% CI (−1.32, −0.42)) and triglyceride levels (MD: −0.35; 95% CI (−0.62, −0.07)). The testosterone and control groups demonstrated no significant difference for other outcomes. In conclusion, we found that TRT can improve glycemic control and decrease triglyceride levels of hypogonadal men with T2DM. Considering the limited number of participants and the confounding factors in our systematic review; additional large, well-designed RCTs are needed to address the metabolic effects of TRT and its long-term influence on hypogonadal men with T2DM.

Crucial role of androgen receptor in vascular H2S biosynthesis induced by testosterone

BACKGROUND AND PURPOSE

Hydrogen sulphide (H2S) is a gaseous mediator strongly involved in cardiovascular homeostasis, where it provokes vasodilatation. Having previously shown that H2 S contributes to testosterone-induced vasorelaxation, here we aim to uncover the mechanisms underlying this effect.

EXPERIMENTAL APPROACH

H2 S biosynthesis was evaluated in rat isolated aortic rings following androgen receptor (NR3C4) stimulation. Co-immunoprecipitation and surface plasmon resonance analysis were performed to investigate mechanisms involved in NR3C4 activation.

KEY RESULTS

Pretreatment with NR3C4 antagonist nilutamide prevented testosterone-induced increase in H2S and reduced its vasodilator effect. Androgen agonist mesterolone also increased H2S and induced vasodilatation; effects attenuated by the selective cystathionine-γ lyase (CSE) inhibitor propargylglycine. The NR3C4-multicomplex-derived heat shock protein 90 (hsp90) was also involved in this effect; its specific inhibitor geldanamycin strongly reduced testosterone-induced H2S production. Neither progesterone nor 17-β-oestradiol induced H2S release. Furthermore, we demonstrated that CSE, the main vascular H2S-synthesizing enzyme, is physically associated with the NR3C4/hsp90 complex and the generation of such a ternary system represents a key event leading to CSE activation. Finally, H2S levels in human blood collected from male healthy volunteers were higher than those in female samples.

CONCLUSIONS AND IMPLICATIONS

We demonstrated that selective activation of the NR3C4 is essential for H2S biosynthesis within vascular tissue, and this event is based on the formation of a ternary complex between cystathionine-γ lyase, NR3C4and hsp90. This novel molecular mechanism operating in the vasculature, corroborated by higher H2S levels in males, suggests that the L-cysteine/CSE/H2S pathway may be preferentially activated in males leading to gender-specific H2S biosynthesis.

The Effect of Testosterone on Cardiovascular Disease

Cardiovascular disease is the leading cause of death in the United States. Testosterone is the principal male sex hormone and plays an important role in men’s health and well-being. Historically, testosterone was believed to adversely affect cardiovascular function. However, contemporary literature has refuted this traditional thinking; testosterone has been suggested to have a protective effect on cardiovascular function through its effects on the vascular system. Data from modern research indicate that hypogonadism is closely related to the development of various cardiovascular risk factors, including hyperlipidemia and insulin resistance. Several studies have demonstrated beneficial effects of testosterone supplementation therapy on reversing symptoms of hypogonadism and improving cardiovascular disease risk profiles. In this review, we perform a critical analysis on the association between testosterone and cardiovascular disease.

Risks and benefits of testosterone therapy in older men

In young men (defined as age<50 years) with classic hypogonadism caused by known diseases of the hypothalamus, pituitary or testes, testosterone replacement therapy induces a number of beneficial effects, for example, the development of secondary sex characteristics, improvement and maintenance of sexual function, and increases in skeletal muscle mass and BMD. Moreover, testosterone treatment in this patient population is associated with a low frequency of adverse events. Circulating testosterone levels decline progressively with age, starting in the second and third decade of life, owing to defects at all levels of the hypothalamic-pituitary-testicular axis. In cohort studies, testosterone levels are associated weakly but consistently with muscle mass, strength, physical function, anaemia, BMD and bone quality, visceral adiposity, and with the risk of diabetes mellitus, coronary artery disease, falls, fractures and mortality. However, the clinical benefits and long-term risks of testosterone therapy--especially prostate-related and cardiovascular-related adverse events--have not been adequately assessed in large, randomized clinical trials involving older men (defined as age>65 years) with androgen deficiency. Therefore, a general policy of testosterone replacement in all older men with age-related decline in testosterone levels is not justified.

A J-shaped association between plasma testosterone and risk of ischemic arterial event in elderly men: the French 3C cohort study

OBJECTIVES

Low plasma testosterone is associated with increased mortality in men. However, the relation between testosterone and cardiovascular disease is uncertain. We assessed the association of plasma sex hormones with the incidence of ischemic arterial disease (IAD) in elderly men.

METHODS

We used data from the French Three-City prospective cohort study (3650 men aged >65 years). A case-cohort design was set up including a random sample of 495 men and 146 incident cases of first IAD event (112 coronary heart disease (CHD) and 34 strokes) after a 4-year follow-up. Plasma total and bioavailable testosterone, total estradiol and sex hormone-binding globulin (SHBG) were measured at baseline. Multivariate hazard ratios (HRs) and 95% confidence intervals for IAD were assessed using Cox model.

RESULTS

After adjustment for cardiovascular risk factors, a J-shaped association between plasma total testosterone and IAD risk was found (p<0.01). The HRs associated with the lowest and the highest total testosterone quintiles relative to the second quintile were 2.23 (95% CI: 1.02; 4.88) and 3.61 (95% CI: 1.55; 8.45) respectively. Additional analysis for CHD showed similar results (HR: 3.11, 95% CI: 1.27; 7.63 and HR: 4.75, 95% CI: 1.75; 12.92, respectively). Similar J-shaped association was observed between bioavailable testosterone and IAD risk (p=0.01). No significant association of estradiol and SHBG with IAD was found.

CONCLUSION

High and low plasma testosterone levels are associated with an increased risk of IAD in elderly men. Optimal range of plasma testosterone may confer cardiovascular protection and these results may have clinical implications in the management of testosterone deficiency.

The effect of androgens on lipids

PURPOSE OF REVIEW

To review recent data concerning the relationship between endogenous testosterone and lipids as well as testosterone replacement therapy and lipids. To describe the effects of sex hormones on cardiovascular disease (CVD) that may act via serum lipids.

RECENT FINDINGS

Low endogenous testosterone is associated with high low-density lipoprotein and low high-density lipoprotein in both cross-sectional and prospective observational studies. Exogenous testosterone administration is associated with decreased high-density lipoprotein coupled with beneficial decreases in low-density lipoprotein and total cholesterol. The overall impact of testosterone administration on CVD is still unclear, with mixed safety results from recent randomized controlled trials.

SUMMARY

There may be CVD risk reduction benefits, including an improved lipid profile, from testosterone administration in hypogonadal men. The overall effect of testosterone on CVD risk has not been definitively determined.