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

Sex hormone-binding globulin exerts sex-related causal effects on lower extremity varicose veins: evidence from gender-stratified Mendelian randomization

Background

The association between serum sex hormones and lower extremity varicose veins has been reported in observational studies. However, it is unclear whether the association reflects a causal relationship. Besides, serum sex hormone-binding globulin (SHBG) has been rarely studied in lower extremity varicose veins. Here, we aim to investigate the association between serum levels of SHBG, testosterone, and estradiol and the risk of lower extremity varicose veins using Mendelian randomization (MR).

Methods

We obtained genome-wide association study summary statistics for serum SHBG levels with 369,002 European participants, serum testosterone levels with 424,907 European participants, serum estradiol levels with 361,194 European participants, and lower extremity varicose veins with 207,055 European participants. First, a univariable MR was performed to identify the causality from SHBG and sex hormone levels to lower extremity varicose veins with several sensitivity analyses being performed. Then, a multivariable MR (MVMR) was performed to further assess whether the causal effects were independent. Finally, we performed a gender-stratified MR to understand the role of genders on lower extremity varicose veins.

Results

Genetically predicted higher serum SHBG levels significantly increased the risk of lower extremity varicose veins in the univariable MR analysis (OR=1.39; 95% CI: 1.13-1.70; P=1.58×10-3). Sensitivity analyses and MVMR (OR=1.50; 95% CI:1.13-1.99; P=5.61×10-3) verified the robustness of the causal relationships. Gender-stratified MR revealed that higher serum SHBG levels were associated with lower extremity varicose veins in both sexes. However, the OR of serum SHBG levels on lower extremity varicose veins risk in females (OR=1.51; 95% CI: 1.23-1.87; P=1.00×10-4) was greater than in males (OR=1.26; 95% CI: 1.04-1.54; P=1.86×10-2).

Conclusions

Serum SHBG levels are positively related to lower extremity varicose veins risk in both sexes, especially in females. This may partly explain the higher prevalence of varicose vines among females.

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

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

Menopause, androgens, and cardiovascular ageing: a narrative review

Cardiovascular disease is the leading cause of death worldwide; however, women tend to be less affected than men during their reproductive years. The female cardiovascular risk increases significantly around the time of the menopausal transition. The loss of the protective action of ovarian oestrogens and the circulating androgens has been implicated in possibly inducing subclinical and overt changes in the cardiovascular system after the menopausal transition. In vitro studies performed in human or animal cell lines demonstrate an adverse effect of testosterone on endothelial cell function and nitric oxide bioavailability. Cohort studies evaluating associations between testosterone and/or dehydroepiandrosterone and subclinical vascular disease and clinical cardiovascular events show an increased risk for women with more pronounced androgenicity. However, a mediating effect of insulin resistance is possible. Data on cardiovascular implications following low-dose testosterone treatment in middle-aged women or high-dose testosterone supplementation for gender affirmatory purposes remain primarily inconsistent. It is prudent to consider the possible adverse association between testosterone and endothelial function during the decision-making process of the most appropriate treatment for a postmenopausal woman.

Pathophysiological effects of androgens on the female vascular system

Sex hormones and their respective receptors affect vascular function differently in men and women, so it is reasonable to assume they play a role in the sex differences in cardiovascular disease states. This review focuses on how the effects of testosterone on arterial vessels impact the female vasculature. In women with androgen-excess polycystic ovary syndrome, and in transgender men, testosterone exposure is associated with high blood pressure, endothelial dysfunction, and dyslipidemia. These relationships suggest that androgens may exert pathophysiological effects on the female vasculature, and these effects on the female vasculature appear to be independent from other co-morbidities of cardiovascular disease. There is evidence that the engagement of androgens with androgen receptor induces detrimental outcomes in the female cardiovascular system, thereby representing a potential causative link with sex differences and cardiovascular regulation. Gender affirming hormone therapy is the primary medical intervention sought by transgender people to reduce the characteristics of their natal sex and induce those of their desired sex. Transgender men, and women with androgen-excess polycystic ovary syndrome both represent patient groups that experience chronic hyperandrogenism and thus lifelong exposure to significant medical risk. The study of testosterone effects on the female vasculature is relatively new, and a complex picture has begun to emerge. Long-term research in this area is needed for the development of more consistent models and controlled experimental designs that will provide insights into the impact of endogenous androgen concentrations, testosterone doses for hormone therapy, and specific hormone types on function of the female cardiovascular system.

Associations of Endogenous Sex Hormones with Carotid Plaque Burden and Characteristics in Midlife Women

CONTEXT

Endogenous sex hormones may be involved in the pathogenesis of cardiovascular disease (CVD) in women. Carotid plaque characteristics, such as echogenicity, an ultrasound measure that reflects plaque composition, may identify unstable plaques that are more likely to rupture, precipitating a CVD event. However, few studies have considered sex steroids in relation to carotid plaque and its characteristics.

OBJECTIVE

To evaluate estrone (E1), estradiol (E2), testosterone (T), sex hormone binding globulin (SHBG), and free T (FT) in relation to carotid plaque in women.

DESIGN, SETTING, AND PARTICIPANTS

In MsHeart, a cross-sectional study of 304 women aged 40 to 60 years, participants underwent a carotid artery ultrasound assessment. The current analysis included MsHeart participants with carotid plaque (n = 141, 46%). E1, E2, and T were assayed using liquid chromatography-tandem mass spectrometry; FT was estimated using ensemble allostery models. Regression models were adjusted for sociodemographic characteristics and CVD risk factors.

MAIN OUTCOMES

Carotid plaque burden (number of plaques, total plaque area [TPA]) and characteristics (calcification, echogenicity) were determined using semi-automated software.

RESULTS

SHBG was inversely related to TPA (odds ratio [OR] 0.39; 95% confidence interval [CI] 0.21, 0.74; multivariable) and higher FTs were associated with greater TPA (OR 2.89; 95% CI 1.31, 6.37; multivariable). Higher E1 was related to echogenicity (OR 2.31; 95% CI 1.26, 4.33; multivariable), characteristic of more stable plaque.

CONCLUSIONS

SHBG and FT are related to TPA while E1 is related to plaque echogenicity, suggesting these hormones have different roles in the development of carotid plaque. Our findings highlight the importance of sex hormones in the development of carotid plaque in midlife women.

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.

Cardiovascular evaluation and serum paraoxonase-1 levels in adolescents with polycystic ovary syndrome

The aim of our study was to evaluate whether cardiovascular disease risks seen in adults with polycystic ovary syndrome (PCOS) develop in adolescents with PCOS using conventional Doppler echocardiography (CDE) and tissue Doppler echocardiography (TDE) or not. The other aim was to investigate the association of paraoxonase-1 (PON-1) level with cardiovascular parameters. 30 PCOS patients and 30 control patients were included in the study. All patients were evaluated with TDE and CDE. Paraoxonase-1 levels of both groups were studied. In CDE study, myocardial performance index (MPI) was higher in the PCOS group than in the control group (0.54 ± 0.11, 0.50 ± 0.12, p = .049, respectively). In the TDE study, early diastolic myocardial velocity (E)'/late diastolic myocardial velocity (A') was lower in PCOS group than in the control group (2.07 ± 0.08, 2.44 ± 0.10, p = .008, respectively). PON-1 was higher in PCOS group than in the control group (26.81 ± 3.05, 18.68 ± 1.18, p = .011, respectively). Cardiovascular disease risks, which are among the long-term complications of PCOS, seem to begin from the early stage of PCOS. The high PON-1 level was thought to increase in response to increased oxidative stress in PCOS.Impact statementWhat is already known on this subject? Polycystic ovary syndrome (PCOS) is one of the most commonly seen endocrinopathy in the adolescent age group. PCOS has detrimental effects on the cardiovascular system in the adult population which is reported in many studies.What the results of this study add? The result of this study showed that cardiovascular effects, which are among the long-term complications of PCOS, seem to begin from the early stage of PCOS. And also, serum paraoxonase-1 level increases in response to the oxidative stress in the adolescent with PCOS.What are the implications of these findings for clinical practice and/or further research? The cardiovascular system evaluation should be started in early phases of PCOS development in the adolescent age group. The potential role of oxidative effect of Paraoxonase-1 on the PCOS needs to be elucidated in further studies.

Association of serum androgens and coronary artery calcium scores in women

OBJECTIVE

To determine the association between serum androgens measured by high-resolution liquid chromatography-mass spectrometry and coronary artery calcium (CAC) scores.

DESIGN

Cross-sectional study.

SETTING

Academic institution.

PATIENT(S)

A total of 239 women, aged 40-75 years, with CAC testing and complete cardiovascular disease risk evaluation. Total T, DHEA, and androstenedione were measured using high-resolution liquid chromatography-mass spectrometry, whereas E₂ and sex hormone-binding globulin were measured using commercial assays.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Independent associations between CAC scores and sex steroids.

RESULT(S)

Overall, 164 subjects had a CAC score < 10, 48 had a CAC score between 10 and 100, and 27 had a score > 100. There were no differences in sex hormone levels between women with CAC scores > 10 vs. CAC scores ≤ 10. In multivariable models adjusting for age, body mass index, and low-density lipoprotein cholesterol, a higher T/E₂ ratio was associated with an elevated CAC score, with an unadjusted odds ratio associated with 1-SD change in log-transformed T/E₂ of 1.38 (95% confidence interval 1.01-1.89) and adjusted OR 1.02 (95% confidence interval 1.002-1.04). Total T, DHEA, androstenedione, sex hormone-binding globulin, and E₂ levels were not associated with increased CAC.

CONCLUSION(S)

In the general population, there are mixed reports regarding the relationship between serum androgens and risk factors for cardiovascular disease, and limited information on the relationship between androgens and subclinical atherosclerosis. Our study shows that increased androgens relative to estrogens may have a weak but independent association with subclinical atherosclerosis, as measured by CAC scores.

Sex differences in endothelial function important to vascular health and overall cardiovascular disease risk across the lifespan

Diseases of the cardiovascular system are the leading cause of morbidity and mortality in men and women in developed countries, and cardiovascular disease (CVD) is becoming more prevalent in developing countries. The prevalence of atherosclerotic CVD in men is greater than in women until menopause, when the prevalence of CVD increases in women until it exceeds that of men. Endothelial function is a barometer of vascular health and a predictor of atherosclerosis that may provide insights into sex differences in CVD as well as how and why the CVD risk drastically changes with menopause. Studies of sex differences in endothelial function are conflicting, with some studies showing earlier decrements in endothelial function in men compared with women, whereas others show similar age-related declines between the sexes. Because the increase in CVD risk coincides with menopause, it is generally thought that female hormones, estrogens in particular, are cardioprotective. Moreover, it is often proposed that androgens are detrimental. In truth, the relationships are more complex. This review first addresses female and male sex hormones and their receptors and how these interact with the cardiovascular system, particularly the endothelium, in healthy young women and men. Second, we address sex differences in sex steroid receptor-independent mechanisms controlling endothelial function, focusing on vascular endothelin and the renin-angiotensin systems, in healthy young women and men. Finally, we discuss sex differences in age-associated endothelial dysfunction, focusing on the role of attenuated circulating sex hormones in these effects.

Androgens, Irregular Menses, and Risk of Diabetes and Coronary Artery Calcification in the Diabetes Prevention Program

CONTEXT

It is unclear whether relative elevations in androgens or irregular menses (IM) are associated with greater cardiometabolic risk among women who are already overweight and glucose intolerant.

RESEARCH DESIGN AND METHODS

We conducted a secondary analysis of the Diabetes Prevention Program (DPP) and the Diabetes Prevention Program Outcomes Study (DPPOS). Participants included women with sex hormone measurements who did not use exogenous estrogen (n = 1422). We examined whether free androgen index (FAI) or IM was associated with diabetes risk during the DPP/DPPOS or with coronary artery calcification (CAC) at DPPOS year 10. Models were adjusted for menopausal status, age, race or ethnicity, randomization arm, body mass index (BMI), and hemoglobin A1c.

RESULTS

Women had an average age of 48.2 ± 9.9 years. Elevations in FAI and IM were associated with greater BMI, waist circumference, and blood pressure and lower adiponectin. FAI was not associated with diabetes risk during the DPP/DPPOS [hazard ratio (HR) 0.97; 95% confidence interval (CI), 0.93 to 1.02] or increased odds of CAC [odds ratio (OR) 1.06; 95% CI, 0.92 to 1.23]. IM was also not associated with diabetes risk during the DPP/DPPOS (HR 1.07; 95% CI, 0.87 to 1.31) or increased odds of CAC (OR 0.89; 95% CI, 0.53 to 1.49). Women who had both relative elevations in FAI and IM had similar diabetes risk and odds of CAC as women without these conditions. Differences by treatment arm and menopausal status were not observed.

CONCLUSIONS

Among midlife women who were already glucose intolerant and overweight, androgen concentrations and IM did not additionally contribute to increased risk for diabetes or CAC.

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.

Androsterone glucuronide to dehydroepiandrosterone sulphate ratio is discriminatory for obese Caucasian women with polycystic ovary syndrome

BACKGROUND

Androsterone glucuronide (ADTG) concentrations have been suggested as a marker of the effects of androgens at the target tissue level. As the mechanism for hyperandrogenemia in obese and nonobese polycystic ovary syndrome (PCOS) may differ, this study compared the different androgen parameters in non-obese compared to obese women with PCOS, and in normal subjects.

METHODS

Eleven non-obese and 14 obese women with PCOS were recruited and compared to 11 control women without PCOS. Total testosterone, dehydroepiandrosterone sulphate (DHEAS), ADTG, and androstenedione were analysed using gold standard tandem mass spectrometry, and the free androgen index (FAI) was calculated.

RESULTS

Total testosterone, ADTG and androstendione levels did not differ between non-obese (body mass index (BMI) ≤25 kg/m²) and obese PCOS (BMI >25 kg/m²) but all were significantly higher than for controls (p < 0.01). The ADTG to DHEAS ratio was significantly elevated 39 ± 6 (p < 0.01) in obese PCOS in comparison to non-obese PCOS and controls (28 ± 5 and 29 ± 4, respectively). The free androgen index (FAI) and insulin resistance (HOMA-IR) were significantly higher in obese PCOS compared to non-obese PCOS and controls (p < 0.01). DHEAS was significantly higher in the non-obese versus obese PCOS (p < 0.01). All androgen parameters were significantly lower and sex hormone binding globulin (SHBG) significantly higher in normal subjects compared to those with obese and non-obese PCOS.

CONCLUSIONS

The ADTG:DHEAS ratio was significantly elevated in obese PCOS compared to non-obese PCOS and controls suggesting that this may be a novel biomarker discriminatory for obese PCOS subjects, perhaps being driven by higher hepatic 5α reductase activity increasing ADTG formation in these women.

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

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

Low Testosterone in Men with Cardiovascular Disease or Risk Factors: To Treat or Not To Treat?

OPINION STATEMENT

Current evidence supports the use of testosterone replacement in men with the clinical-biochemical syndrome of hypogonadism, defined as low testosterone serum levels and symptoms such as fatigue, exercise intolerance, erectile dysfunction, low libido, or depression. Although the evidence consistently shows that hypogonadism is associated with elevated cardiovascular risk, evidence is mixed regarding whether testosterone (T) replacement provides cardiovascular (CV) benefit or harm. For a man with symptomatic hypogonadism in the setting of CV disease, clinical heart failure, and/or traditional CV risk factors (hypertension, diabetes, and hyperlipidemia), a balanced approach would be to counsel him that overall, the evidence should not dissuade him from utilizing T replacement for non-cardiac symptom relief but that more data are needed before a definitive recommendation can be made about T replacement for CV benefit. The preponderance of available evidence, reviewed in this article, suggests that T replacement, at appropriate doses and with monitored response, is likely to be safe for men with CV disease or CV risk factors and may even reduce major adverse cardiovascular events (MACE). The 2015 American Association of Clinical Endocrinologists and American College of Endocrinology position statement supports this stance and calls for improved prospective data. There is a clear need for a large, prospective randomized trial evaluating the impact of T replacement on MACE, for men both with and without CV disease or CV risk factors. Clinicians should be aware that all men who elect to take T replacement therapy require regular follow-up with the prescribing physician to include both clinical assessment and surveillance laboratory assessment of total T level, complete blood count, and prostate specific antigen.