Mechanisms responsible for endothelial dysfunction associated with acute estrogen deprivation in normotensive women

Sex Disparities in Medical Management: Influence on Morbidity in Peripheral Arterial Disease

OBJECTIVE

Peripheral artery disease (PAD) has traditionally been identified as a male-dominant disease, however, current literature suggests that female patients may be at increased risk of adverse outcomes. Given key differences between sexes, we conducted a retrospective review to identify pre-surgery risk predictors that may increase morbidity within the female PAD population.

METHODS

Data was extracted from the Vascular Quality Initiative database for patients who underwent supra- or infra-inguinal bypass surgery for PAD between 2009 and 2020. Binary logistic regression was used to assess for sex differences in risk predictors, drug administration characteristics, and post-operative outcomes; analysis was adjusted for potential covariates.

RESULTS

A total of 79,981 patients were included based on our eligibility criteria, 34% of which were female. Female patients typically presented at an older age, were more frequently hypertensive and diabetic, and were significantly less likely to be prescribed ACE-inhibitors, anticoagulants, and statin pre-operatively. Women had a significantly higher post-operative risk of all-cause morbidity (1.06 (1.03, 1.09);p=0.004), mortality (1.09 (1.05, 1.13);p<0.001), stroke (1.48 (1.35, 1.62);p<0.001), and major adverse cardiovascular events (1.19 (1.10, 1.28);p<0.001) when compared to male patients. No pre-operative statin use was a significantly greater predictor for all cause morbidity in women.

CONCLUSIONS

Following surgery for PAD, our results suggests that female patients have a significantly greater risk of adverse outcomes as compared to male patients. Reduced administration of key medication including statin and ACE-inhibitors along with a greater comorbidity burden in female patients may be major contributors to this greater morbidity risk.

Salt-sensitive hypertension: role of endothelial and vascular dysfunction and sex

For the last 120 years, the contribution of salt has been identified in the pathophysiological elevation of blood pressure. Since then, both human and experimental murine studies have begun to elucidate the key mechanisms contributing to the development of salt-sensitive hypertension. Numerous mechanisms, including increased plasma volume, sodium retention, impaired autoregulatory capability, inflammation, and endothelial and vascular dysfunction, contribute to deleterious elevations in blood pressure during salt sensitivity. The endothelium plays a critical role in blood flow regulation, renal blood flow, and blood pressure elevations and in migrating immune cells to end-organs, contributing to end-organ damage and fibrosis. In this review, we will consider the clinical studies setting the foundation for the definition of salt-sensitive hypertension, murine models to study endothelial and vascular contributions, and endothelial cell cultures that have shed light on signaling mechanisms. Lastly, we will discuss the sex-dependent physiology and mechanisms contributing to salt-sensitive hypertension development and their clinical implications.

Brachial-Ankle Pulse Wave Velocity as a Predictor of Diabetes Development: Elevated Risk Within Normal Range Values in a Low-Risk Population

BACKGROUND

Recent studies have suggested that increased brachial-ankle pulse wave velocity (baPWV) is a risk factor for diabetes. Exploring its relationship with insulin resistance is of interest, necessitating further studies across different sexes and age groups.

METHODS AND RESULTS

This cohort study involved 119 170 Korean adults with an average age of 39.8 years, none of whom had diabetes at baseline. As part of a health screening, baPWV measurements were taken. Over a median follow-up period of 5.6 years, fasting blood glucose, glycated hemoglobin, insulin levels, and questionnaire responses were collected. The risk of developing diabetes was evaluated using a flexible parametric proportional hazards model with data stratified by sex and age group (<40 versus ≥40 years). During the follow-up period, diabetes was diagnosed in 5966 participants (5.0%). A fully adjusted model found that the hazard ratios for diabetes onset associated with baPWV quartiles Q2 (1171.0-1270.5 cm/s), Q3 (1271.0-1376.0 cm/s), and Q4 (≥1376.5 cm/s) compared with Q1 (<1171.0 cm/s) were 1.06 (95% CI, 0.96-1.17), 1.25 (1.14-1.38), and 1.48 (1.34-1.62), respectively (P for trend <0.001). A significant sex-based interaction was noted in this association, with women showing a higher risk of diabetes development. Furthermore, higher baPWV quartiles were associated with an increased risk of developing insulin resistance, defined as the homeostatic model assessment of insulin resistance.

CONCLUSIONS

These findings highlight the importance of arterial stiffness, as measured by elevated baPWV, in the development of diabetes and insulin resistance. Notably, this study highlighted a strong association, particularly among women.

The ASAP study: association of atherosclerosis with pathobiology in a caucasian cohort-a study of 3400 autopsy reports

Cardiovascular plaques result from atherosclerosis. Autopsy investigations of unnatural deaths provide atherosclerosis research. A Central European cohort was studied in a cross-sectional study to determine the origin of atherosclerosis and the link between arterial status and pathobiological variables. This study incorporated 3400 autopsy reports (n = 2318 men; aged 0─96 years; 1928─2010) of persons who died by unnatural causes (suicide, homicide, accident). Age, sex, BMI, abdominal fat thickness, and arterial status of six vascular areas were gathered. The arterial state was divided into five subgroups according to its status. BMI declined from 22.82 kg/m2 in 1931 to 18.43 kg/m2 in 1947, then increased to 27.88 kg/m2 in 2005. Atherosclerotic degeneration begins in the abdominal aorta, then the thoracic, coronary, carotid, ascending, and cerebral arteries. All blood arteries deteriorated faster in men than women until 55. Abdominal aorta damage was the fastest in both sexes. Age is the biggest predictor of atherosclerosis, followed by sex, overweight, and abdominal thickness, according to logistic regression. This is the largest Central European autopsy investigation of six vascular areas. Both sexes develop atherosclerosis in the abdominal aorta in the first decade of life. Being overweight increases the risk. The findings of this study aid healthcare providers in personalized therapy.

Estrone-mediated lowering of ROS and NOX4 improves endothelial function in ovariectomized wistar rats

Estrone (E1) constitutes the primary component in oral conjugated equine estrogens (CEEs) and serves as the principal estrogen precursor in the female circulation in the post-menopause. E1 induces endothelium-dependent vasodilation and activate PI3K/NO/cGMP signaling. To assess whether E1 mitigates vascular dysfunction associated with postmenopause and explore the underlying mechanisms, we examined the vascular effects of E1 in ovariectomized (OVX) rats, a postmenopausal experimental model. Blood pressure was measured using tail-cuff plethysmography, and aortic rings were isolated to assess responses to phenylephrine, acetylcholine (ACh), and sodium nitroprusside. Responses to ACh in rings pre-incubated with superoxide dismutase (SOD), catalase (CAT), or apocynin were also evaluated. Protein expression of SOD, CAT, NOX1, NOX2, and NOX4 was determined by Western blotting. E1 treatment resulted in decreased body weight and retroperitoneal fat, increased uterine weight, and prevented elevated blood pressure in the OVX group. Furthermore, E1 improved endothelium-dependent ACh vasodilation, activated compensatory antioxidant mechanisms - i.e. increased SOD and CAT antioxidant enzymes activity, and decreased NOX4 expression. This, in turn, helped prevent oxidative stress and endothelial dysfunction in OVX rats. Additionally, E1 treatment reversed the increased total LDL cholesterol observed in the OVX group. The findings underscore protective effects of E1 on the cardiovascular system, counteracting OVX-related oxidative stress and endothelial dysfunction in Wistar rats. E1 exhibits promising therapeutic benefits for managing cardiovascular health, particularly in postmenopausal conditions.

Endothelial dysfunction and cardiovascular diseases: The role of human induced pluripotent stem cells and tissue engineering

Cardiovascular disease (CVD) remains to be the leading cause of death globally today and therefore the need for the development of novel therapies has become increasingly important in the cardiovascular field. The mechanism(s) behind the pathophysiology of CVD have been laboriously investigated in both stem cell and bioengineering laboratories. Scientific breakthroughs have paved the way to better mimic cell types of interest in recent years, with the ability to generate any cell type from reprogrammed human pluripotent stem cells. Mimicking the native extracellular matrix using both organic and inorganic biomaterials has allowed full organs to be recapitulated in vitro. In this paper, we will review techniques from both stem cell biology and bioengineering which have been fruitfully combined and have fueled advances in the cardiovascular disease field. We will provide a brief introduction to CVD, reviewing some of the recent studies as related to the role of endothelial cells and endothelial cell dysfunction. Recent advances and the techniques widely used in both bioengineering and stem cell biology will be discussed, providing a broad overview of the collaboration between these two fields and their overall impact on tissue engineering in the cardiovascular devices and implications for treatment of cardiovascular disease.

Timing of hormone therapy and its association with cardiovascular risk and metabolic parameters in 4-vinylcyclohexene diepoxide-induced primary ovarian insufficiency mouse model

OBJECTIVE

To evaluate the effects of various initiation time points and durations of hormone therapy (HT) on cardiovascular and metabolic parameters of premenarche, primary ovarian insufficiency (POI) mouse model, induced by 4-vinylcyclohexene diepoxide.

METHODS

A total of 50 mice at 4 weeks of age were developed into POI mouse model, further randomly categorized into 5 groups: control group without any intervention; no HT group with only high-fat diet (NT); group 1 with delayed estradiol treatment (T1); group 2 with on-time, continuous estradiol treatment (T2); and group 3 with on-time estradiol treatment but early stop (T3). Cardiovascular risk and metabolic parameters were measured.

RESULTS

Presenting with similar body weights, blood glucose levels of T1, T2, and T3 were all significantly lower than NT (p < .001). Serum total cholesterol and insulin were also significantly lower in all HT groups than in NT, especially in T2 (p < .001). For serum low-density lipoprotein-cholesterol, only T2 resulted in the statically lower level than those of NT, T1, and T3 (p < .001). Aortic thickness was significantly increased with aggravated fibrotic change of the intima in NT, and such consequence was significantly ameliorated in HT groups, mostly lowered in T2 (p < .05). Last, serum pro-inflammatory cytokines were significantly low in the HT groups than in NT, especially in T2 with the lowest level (p < .05). .

CONCLUSIONS

On-time, continuous E2 treatment immediately after a biologic estrogen deprivation event significantly reduced metabolic and cardiovascular risks in young, pre-menarche female mouse models of POI, confirming decreased serum levels of pro-inflammatory cytokines.

Caloric restriction-mimetics for the reduction of heart failure risk in aging heart: with consideration of gender-related differences

The literature is full of claims regarding the consumption of polyphenol or polyamine-rich foods that offer some protection from developing cardiovascular disease (CVD). This is achieved by preventing cardiac hypertrophy and protecting blood vessels through improving the function of endothelium. However, do these interventions work in the aged human hearts? Cardiac aging is accompanied by an increase in left ventricular hypertrophy, along with diastolic and systolic dysfunction. It also confers significant cardiovascular risks for both sexes. The incidence and prevalence of CVD increase sharply at an earlier age in men than women. Furthermore, the patterns of heart failure differ between sexes, as do the lifetime risk factors. Do caloric restriction (CR)-mimetics, rich in polyphenol or polyamine, delay or reverse cardiac aging equally in both men and women? This review will discuss three areas: (1) mechanisms underlying age-related cardiac remodeling; (2) gender-related differences and potential mechanisms underlying diminished cardiac response in older men and women; (3) we select a few polyphenol or polyamine rich compounds as the CR-mimetics, such as resveratrol, quercetin, curcumin, epigallocatechin gallate and spermidine, due to their capability to extend health-span and induce autophagy. We outline their abilities and issues on retarding aging in animal hearts and preventing CVD in humans. We discuss the confounding factors that should be considered for developing therapeutic strategies against cardiac aging in humans.

Nitric oxide, aging and aerobic exercise: Sedentary individuals to Master's athletes

Aging is associated with a decline in physiological function and exercise performance. These effects are mediated, at least in part, by an age-related decrease in the bioavailability of nitric oxide (NO), a ubiquitous gasotransmitter and regulator of myriad physiological processes. The decrease in NO bioavailability with aging is especially apparent in sedentary individuals, whereas older, physically active individuals maintain higher levels of NO with advancing age. Strategies which enhance NO bioavailability (including nutritional supplementation) have been proposed as a potential means of reducing the age-related decrease in physiological function and enhancing exercise performance and may be of interest to a range of older individuals including those taking part in competitive sport. In this brief review we discuss the effects of aging on physiological function and endurance exercise performance, and the potential role of changes in NO bioavailability in these processes. We also provide a summary of current evidence for dietary supplementation with substrates for NO production - including inorganic nitrate and nitrite, l-arginine and l-citrulline - for improving exercise capacity/performance in older adults. Additionally, we discuss the (limited) evidence on the effects of (poly)phenols and other dietary antioxidants on NO bioavailability in older individuals. Finally, we provide suggestions for future research.

Effects of the Follicular Menstrual Phase on Forearm Vascular Conductance in Abdominal Obese Premenopausal Women During Graded Handgrip Exercise

Purpose

Previous studies have reported a sympatholytic action of estrogen on the vasculature in response to increased sympathetic outflow, an effect most notable during exercise, providing for necessary increases in blood flow to working muscle. In contrast, elevated concentrations of progesterone can inhibit this action of estrogen, impairing increases in blood flow. We hypothesize that the peak concentration of estrogen during the proliferative portion of the follicular phase of the menstrual cycle in female humans will increase vascular conductance during exercise when the effects of progesterone are negligible. In addition, we hypothesize that overweight abdominally obese females will have an attenuated conductance response to dynamic exercise during the same menstrual phase.

Methods

Participants engaged in graded forearm exercise using an isotonic handgrip dynometer with sequential increases in resistance at a cadence of 30 contractions/minute until task failure. They performed exercise at time points of the menstrual cycle corresponding to low concentrations of both sex hormones and elevated estrogen, while progesterone remained low. Blood flow and vascular conductance were measured using Doppler ultrasound.

Results

This revealed a trend that abdominal obese women during a phase of low estrogen had a lower overall blood flow and vascular conductance response than healthy controls at matching resistance stages during rest and exercise. This group difference was attenuated during the proliferative phase with elevated circulating estrogen. There is not a statistically significant interaction between Ovarian Phase and Weight group (P = 0.778).

Conclusion

The results indicate that overweight women are at a disadvantage during exercise in increasing blood flow to working muscles, which can be detrimental to overall fitness improvement during the early and potentially late follicular phase of the menstrual cycle.

Sex Differences in Peripheral Artery Disease

Peripheral artery disease (PAD) is a prevalent condition that confers substantial morbidity and mortality and remains underdiagnosed as well as undertreated in the overall population. Although PAD prevalence is similar or higher in women compared with men, associations of traditional and nontraditional risk factors with PAD and clinical manifestations of PAD differ by sex and may contribute to delayed or lack of diagnosis in women. Such sex-based differences in the manifestation of PAD may arise from sexual dimorphism in the vascular substrate in health as well as sex variation in the responses to vascular stressors. Despite the availability of proven therapies for improving symptoms and reducing risk of ischemic cardiovascular and limb events among patients with diagnosed PAD, important sex differences in treatment and outcomes have been observed. We provide an overview of current knowledge regarding sex differences in the epidemiology, pathophysiology, clinical presentation, and management of PAD.

Sex Differences in Molecular Mechanisms of Cardiovascular Aging

Cardiovascular disease (CVD) is still the leading cause of illness and death in the Western world. Cardiovascular aging is a progressive modification occurring in cardiac and vascular morphology and physiology where increased endothelial dysfunction and arterial stiffness are observed, generally accompanied by increased systolic blood pressure and augmented pulse pressure. The effects of biological sex on cardiovascular pathophysiology have long been known. The incidence of hypertension is higher in men, and it increases in postmenopausal women. Premenopausal women are protected from CVD compared with age-matched men and this protective effect is lost with menopause, suggesting that sex-hormones influence blood pressure regulation. In parallel, the heart progressively remodels over the course of life and the pattern of cardiac remodeling also differs between the sexes. Lower autonomic tone, reduced baroreceptor response, and greater vascular function are observed in premenopausal women than men of similar age. However, postmenopausal women have stiffer arteries than their male counterparts. The biological mechanisms responsible for sex-related differences observed in cardiovascular aging are being unraveled over the last several decades. This review focuses on molecular mechanisms underlying the sex-differences of CVD in aging.

Vascular Aging in Rodent Models: Contrasting Mechanisms Driving the Female and Male Vascular Senescence

Increasing scientific interest has been directed to sex as a biological and decisive factor on several diseases. Several different mechanisms orchestrate vascular function, as well as vascular dysfunction in cardiovascular and metabolic diseases in males and females. Certain vascular sex differences are present throughout life, while others are more evident before the menopause, suggesting two important and correlated drivers: genetic and hormonal factors. With the increasing life expectancy and aging population, studies on aging-related diseases and aging-related physiological changes have steeply grown and, with them, the use of aging animal models. Mouse and rat models of aging, the most studied laboratory animals in aging research, exhibit sex differences in many systems and physiological functions, as well as sex differences in the aging process and aging-associated cardiovascular changes. In the present review, we introduce the most common aging and senescence-accelerated animal models and emphasize that sex is a biological variable that should be considered in aging studies. Sex differences in the cardiovascular system, with a focus on sex differences in aging-associated vascular alterations (endothelial dysfunction, remodeling and oxidative and inflammatory processes) in these animal models are reviewed and discussed.

Reversible Cerebral Vasoconstriction Syndrome Associated with Levonorgestrel-Releasing Intrauterine System

Reversible cerebral vasoconstriction syndromes (RCVS) is a rare disease that is characterized by reversible multifocal stenosis of the cerebral arteries with various clinical manifestations. Though the pathomechanism of RCVS was unclear, we reported RCVS related to the levonorgestrel-releasing intrauterine system (IUS). A previous healthy 36-year-old woman had thunderclap headache after implanting the levonorgestrel-releasing IUS a year ago. In the serial angiography, we initially found left vertebra artery (VA), and then additionally new stenosis of both anterior cerebral arteries and middle cerebral arteries (MCA). Bilateral MCA stenosis improved but developed stenosis of right VA after a week. The mean flow velocities of both MCA increased in the first transcranial doppler (TCD), but normalized in the follow up TCD. Levonorgestrel might act as the vasoconstrictitve factor that increased the level of endothelin-1, diminished the release of NO and raised oxidative low-density lipoprotein (LDL). Although the exact pathological mechanisms for RCVS were not yet elucidated, this case might help clinicians understand the mechanisms of RCVS.

Report from a large and comprehensive single-center Women's Health Cardiology Clinic

Objective:

This article describes the women population and work at a unique Women’s Health Cardiology Clinic in order to raise cardiovascular disease awareness with an emphasis on women-specific risk factors, and thus to improve women’s clinical outcomes. This expectantly will aid in opening similar centers allowing more women to get superior care.

Methods:

Electronic medical records of women referred to the Women’s Health Cardiology Clinic were analyzed. The statistical analysis is descriptive in nature. Women’s Health Cardiology Clinic personnel work as a multidisciplinary team, and patients receive specialized diagnostic tests and treatments. Referrals are by physicians according to traditional and women’s specific risk factors for cardiovascular disease.

Results:

985 women visited the Women’s Health Cardiology Clinic, accumulating 2062 visits. Median age was 57.5 years. The majority of the women were menopausal (575 women, 58%), 62 pregnant with complications and 25 oncology patients. At least, 30% of women had diabetes/hypertension/or dyslipidemia. 72 women had a history of either cerebrovascular event or acute coronary syndrome, and 139 women had evidence of atherosclerosis. Overall, 388 women underwent endothelial function test, 40% of these women had a score indicating endothelial dysfunction. 277 women underwent a psychological intervention.

Conclusion:

Described here are the experiences from a multidisciplinary Women’s Health Cardiology Clinic using a gender-specific cardiovascular care approach for women geared toward improved health and wellbeing. It is of utmost importance that this report will raise women-specific cardiovascular disease risk factors awareness in order to promote women’s cardiovascular and overall health.

Estrogen and estrogen receptors in kidney diseases

Acute kidney injury (AKI) and chronic kidney disease (CKD) are posing great threats to global health within this century. Studies have suggested that estrogen and estrogen receptors (ERs) play important roles in many physiological processes in the kidney. For instance, they are crucial in maintaining mitochondrial homeostasis and modulating endothelin-1 (ET-1) system in the kidney. Estrogen takes part in the kidney repair and regeneration via its receptors. Estrogen also participates in the regulation of phosphorus homeostasis via its receptors in the proximal tubule. The ERα polymorphisms have been associated with the susceptibilities and outcomes of several renal diseases. As a consequence, the altered or dysregulated estrogen/ERs signaling pathways may contribute to a variety of kidney diseases, including various causes-induced AKI, diabetic kidney disease (DKD), lupus nephritis (LN), IgA nephropathy (IgAN), CKD complications, etc. Experimental and clinical studies have shown that targeting estrogen/ERs signaling pathways might have protective effects against certain renal disorders. However, many unsolved problems still exist in knowledge regarding the roles of estrogen and ERs in distinct kidney diseases. Further research is needed to shed light on this area and to enable the discovery of pathway-specific therapies for kidney diseases.

Decline in endothelial function across the menopause transition in healthy women is related to decreased estradiol and increased oxidative stress

Endothelial function declines progressively across stages of the menopause transition; however, the mechanisms contributing to this decline are unknown. We hypothesized that differences in endothelial function among pre-, peri, and postmenopausal women are related to differences in estradiol and oxidative stress. Brachial artery flow-mediated dilation (FMD) was measured in 87 healthy women categorized by menopause stage (24 premenopausal, 17 early and 21 late perimenopausal, and 25 postmenopausal) before and after 3 days of ovarian hormone suppression (gonadotropin releasing hormone antagonist [GnRHant]) alone, and an additional 3 days of GnRHant with concurrent transdermal estradiol or placebo add-back treatment. In 82 women, FMD during acute vitamin C (antioxidant) infusion was measured before and after GnRHant + add-back. Before GnRHant, FMD was different among groups (p < 0.005; reduced across stages of menopause). Vitamin C increased FMD in late peri- and post- (p < 0.005) but not pre- or early perimenopausal women (p > 0.54). After GnRHant alone, FMD decreased in pre- and peri- (p < 0.01), but not postmenopausal women, and was restored to premenopausal levels by estradiol add-back in the pre- and perimenopausal groups. Vitamin C improved FMD in pre-, peri-, and postmenopausal women on GnRHant + placebo. There was no effect of vitamin C on FMD in women on GnRHant + estradiol. These observations support the concept that the decline in endothelial function across the menopause transition is related to the loss of ovarian estradiol. The decline in estradiol may alter redox balance, thereby increasing oxidative stress and impairing endothelial function.

Estrogen-related mechanisms in sex differences of hypertension and target organ damage

Hypertension (HTN) is a primary risk factor for cardiovascular (CV) events, target organ damage (TOD), premature death and disability worldwide. The pathophysiology of HTN is complex and influenced by many factors including biological sex. Studies show that the prevalence of HTN is higher among adults aged 60 and over, highlighting the increase of HTN after menopause in women. Estrogen (E2) plays an important role in the development of systemic HTN and TOD, exerting several modulatory effects. The influence of E2 leads to alterations in mechanisms regulating the sympathetic nervous system, renin-angiotensin-aldosterone system, body mass, oxidative stress, endothelial function and salt sensitivity; all associated with a crucial inflammatory state and influenced by genetic factors, ultimately resulting in cardiac, vascular and renal damage in HTN. In the present article, we discuss the role of E2 in mechanisms accounting for the development of HTN and TOD in a sex-specific manner. The identification of targets with therapeutic potential would contribute to the development of more efficient treatments according to individual needs.

Effects of resveratrol or estradiol on postexercise endothelial function in estrogen-deficient postmenopausal women

Regular exercise enhances endothelial function in older men, but not consistently in estrogen-deficient postmenopausal women. Estradiol treatment improves basal endothelial function and restores improvements in endothelial function (flow-mediated dilation, FMD) to aerobic exercise training in postmenopausal women; however, estradiol treatment is controversial. Resveratrol, an estrogen receptor ligand, enhances exercise training effects on cardiovascular function and nitric oxide (NO) release in animal models, but impairs exercise training effects in men. We conducted a randomized cross-over, double-blinded, placebo-controlled pilot study to determine whether acute (single dose) resveratrol (250-mg tablet) or estradiol (0.05 mg/day transdermal patch) treatment enhances FMD at rest and after a single bout of moderate-intensity aerobic exercise in healthy estrogen-deficient postmenopausal women (n = 15, 58.1 ± 3.2 yr). FMD was measured before and after (30, 60, and 120 min) a 40-min bout of moderate-intensity treadmill exercise (60-75% peak heart rate) under the respective conditions (separated by 1-2 wk). FMD was higher (P < 0.05) before exercise and at all post-exercise time points in the resveratrol and estradiol conditions compared to placebo. FMD was increased from baseline by 120 min postexercise in the estradiol condition (P < 0.001), but not resveratrol or PL conditions. Consistent with our previous findings, estradiol also enhances endothelial function in response to acute endurance exercise. Although resveratrol improved basal FMD, there was no apparent enhancement of FMD to acute exercise and, therefore, may not act as an estradiol mimetic.NEW & NOTEWORTHY The benefits of endurance exercise training on endothelial function are diminished in estrogen-deficient postmenopausal women, but estradiol treatment appears to restore improvements in endothelial function in this group. We show that basal endothelial function is enhanced with both acute estradiol and resveratrol treatments in estrogen-deficient postmenopausal women, but endothelial function is only enhanced following acute endurance exercise with estradiol treatment.

Endothelial Vascular Function as a Surrogate of Vascular Risk and Aging in Women

Cardiovascular disease is the leading cause of morbidity and mortality in women. We suggest the need to develop a paradigm that connects sex- and age-specific nontraditional risk factors that serve as a common mechanism ultimately leading to an increased risk of cardiovascular events. Vascular injury with abnormal repair leading to functional, rather than structural, abnormalities can be regarded as accelerated vascular aging. It emerges as a common feature that can trigger the early diagnosis and risk stratification for cardiovascular disease in women. We discuss sex-specific risk factors that can contribute to vascular injury with age, and these might not always be considered by cardiovascular physicians. It is important for the primary physician to be aware of these risk factors to enable more intensified management of this at-risk population. Novel technologies that allow the assessment of vascular function noninvasively can serve as key diagnostic and therapeutic tools with which we can identify such individuals and target therapy to manage this important patient population appropriately and effectively. We hope that this article will stimulate interest in this field and encourage further research in these important areas.

Late Onset of Estrogen Therapy Impairs Carotid Function of Senescent Females in Association with Altered Prostanoid Balance and Upregulation of the Variant ERα36

Recent analysis of clinical trials on estrogen therapy proposes the existence of a therapeutic window of opportunity for the cardiovascular benefits of estrogens, which depend on women's age and the onset of therapy initiation. In this study, we aimed to determine how vascular senescence and the onset of estrogen treatment influence the common carotid artery (CCA) function in senescent and non-senescent females. Ovariectomized female senescence-accelerated (SAMP8) or non-senescent (SAMR1) mice were treated with vehicle (OVX) or 17β-estradiol starting at the day of ovariectomy (early-onset, E₂E) or 45 days after surgery (late-onset, E₂L). In SAMR1, both treatments, E₂E and E₂L, reduced constriction to phenylephrine (Phe) in CCA [(AUC) OVX: 193.8 ± 15.5; E₂E: 128.1 ± 11.6; E₂L: 130.2 ± 15.8, p = 0.004] in association with positive regulation of NO/O2- ratio and increased prostacyclin production. In contrast, E₂E treatment did not modify vasoconstrictor responses to Phe in OVX-SAMP8 and, yet, E₂L increased Phe vasoconstriction [(AUC) OVX: 165.3 ± 10; E₂E: 183.3 ± 11.1; E₂L: 256.3 ± 30.4, p = 0.005]. Increased vasoconstriction in E₂L-SAMP8 was associated with augmented thromboxane A2 and reduced NO production. Analysis of wild-type receptor alpha (ERα66) expression and its variants revealed an increased expression of ERα36 in E₂L-SAMP8 in correlation with unfavorable effects of estrogen in those animals. In conclusion, estrogen exerts beneficial effects in non-senescent CCA, regardless of the initiation of the therapy. In senescent CCA, however, estrogen loses its beneficial action even when administered shortly after ovariectomy and may become detrimental when given late after ovariectomy. Aging and onset of estrogen treatment are two critical factors in the mechanism of action of this hormone in CCA.

A Review of the Actions of Endogenous and Exogenous Vasoactive Substances during the Estrous Cycle and Pregnancy in Rats

Vascular endothelium plays a key role in regulating cardiovascular homeostasis by controlling the vascular tone. Variations in sex hormones during the reproductive cycle of females affect the homeostasis of the cardiovascular system. Also, the evidence shows that estrogens show a cardioprotective effect. On this basis, this study describes some vascular responses induced by vasoactive substances during the estrous cycle in rats. We obtained the information available on this topic from the online databases that included scientific articles published in the Web of Science, PubMed, and Scielo. Many investigations have evaluated the vasoactive response of substances such as acetylcholine and norepinephrine during the estrous cycle. In this review, we specifically described the vascular response to vasoactive substances in rats during the estrous cycle, pregnancy, and in ovariectomized rats. In addition, we discussed the existence of different signaling pathways that modulate vascular function. The knowledge of these effects is relevant for the optimization and development of new treatments for some vascular pathologies.

Elevated plasma homocysteine and cysteine are associated with endothelial dysfunction across menopausal stages in healthy women

Hyperhomocysteinemia is associated with endothelial dysfunction and increased cardiovascular disease (CVD). We determined whether elevated homocysteine (Hcy) and markers of Hcy metabolism were associated with the previously reported endothelial dysfunction across stages of the menopause transition. Brachial artery flow-mediated dilation (FMD) and plasma concentrations of Hcy, cysteine, and methionine were measured in healthy women (n = 128) 22-70 yr of age categorized as premenopausal (n = 35), perimenopausal (early: n = 16; late: n = 21), and postmenopausal (early: n = 21; late: n = 35). Dietary intake of micronutrients involved in Hcy metabolism (e.g., vitamins B6, B12, folate) was assessed in a subpopulation of women. Hcy and cysteine concentrations were progressively higher, and methionine was progressively lower across menopausal stages (all P < 0.005). The higher Hcy and cysteine concentrations correlated with lower circulating estradiol levels (r = -0.49 and -0.50, respectively, both P < 0.001). FMD was inversely correlated with Hcy (r = -0.25, P = 0.004) and cysteine (r = -0.39, P < 0.001) and positively correlated with methionine concentrations (r = 0.25, P = 0.005). Dietary intake of vitamins B6 and B12 (both P < 0.05) were lower in postmenopausal women. Vitamin B12 intake correlated with FMD (r = 0.22, P = 0.006). These data suggest that declines in estradiol across stages of the menopause transition may lead to elevations in Hcy and cysteine that may contribute to endothelial dysfunction in postmenopausal women. Future studies should examine whether targeting Hcy metabolism during the perimenopausal to early postmenopausal period with interventions, including diet, attenuates or reverses the decline in endothelial function in women. NEW & NOTEWORTHY Declines in circulating estradiol across the stages of the menopausal transition may lead to elevations in Hcy and cysteine concentrations that may contribute to endothelial dysfunction. Abnormalities in the Hcy metabolic pathways, possibly related to dietary deficiencies of vitamins B12 and B6 and folate, may contribute to elevations in Hcy and cysteine concentrations. Findings also suggest that higher cysteine levels may be more damaging to the vascular endothelium than Hcy.

Modulatory influence of sex hormones on vascular aging

This review summarizes a presentation given during the "Countermeasures to Cardiovascular Aging Symposium" that was part of the American Physiological Society Conference on Cardiovascular Aging: New Frontiers and Old Friends held in Westminster, CO, in August 2017. Endothelial dysfunction, a characteristic of vascular aging, is a major risk factor for age-associated cardiovascular diseases. In women, the decline in endothelial function is attenuated until menopause, whereafter the rate of decline accelerates to match that seen in men. Sex differences in the decline in endothelial function have been attributed to changes in sex hormones with aging. Women have a progressive impairment in endothelial function across the stages of the menopause transition, related in part to declining estradiol levels. In contrast to women, little is known about the impact of declining testosterone levels on endothelial function in men. Some evidence suggests greater endothelial dysfunction in men with low testosterone compared with men with higher testosterone. The underlying causes of endothelial dysfunction with sex hormone deficiency are unknown but may be related to endothelial nitric oxide synthase dysfunction and oxidative stress. Lifestyle behaviors, including habitual endurance exercise, attenuates and reverses the age-associated decline in endothelial function in older men. However, in older women, these exercise adaptations are diminished or absent, possibly related to estrogen deficiency. Understanding how declines in sex hormones contribute to the vascular aging process in both women and men will inform effective sex-specific intervention strategies to preserve vascular health and prevent cardiovascular diseases.

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.

Intersection between gonadal function and vascular aging in women

Vascular aging, characterized by endothelial dysfunction and large elastic arterial stiffening, is a major risk factor for age-associated cardiovascular disease (CVD). Although women have a lower prevalence of CVD until midlife, prevalence rates increase rapidly coincident with the menopausal transition to match those observed in men. The menopausal transition, or perimenopause, is a chaotic period that is associated with increased symptoms (e.g., hot flashes, depressed mood, anxiety, sleep disturbances) and CVD risk factors due to changes in the hormonal environment. Because these quality of life factors and CVD risk factors also change with aging, the arteries of women appear to endure a double insult. Our laboratory has been investigating how changes in gonadal function and hormone levels with the menopause transition impacts the vascular aging process in healthy women. Our work has shown that vascular endothelial function progressively declines, and large elastic arterial stiffness is greater across the stages of the menopausal transition. This acceleration in vascular aging may be due to the loss of vasodilatory, antioxidant, anti-inflammatory, and antiproliferative effects of estradiol on the vascular wall. This minireview discusses the impact of changes in gonadal function and hormones with the menopausal transition on vascular aging in women and areas for investigations to further our understanding of the intersection between gonadal function and vascular aging.

Flow mediated vasodilation compared with carotid intima media thickness in the evaluation of early cardiovascular damage in menopausal women and the influence of biological and psychosocial factors

Background

Women after menopause increase risk for cardiovascular disease and several factors may be related. The purpose was to study biological and psychosocial factors associated with early cardiovascular damage in pre- and postmenopausal women, assessed with carotid intima-media thickness vs flow-mediated dilatation.

Methods

Women 45 to 57 years old were grouped in the pre- (n = 60), early (n = 58) and late post-menopause (n = 59). Anthropometric, metabolic and hormonal data were registered, as well as measures of depression, anxiety, submission, perceived stress, and sleep alterations. Heart Rate Variability was recorded to obtain the information regarding sympathovagal balance. Carotid intima-media thickness and flow-mediated dilatation were assessed by ultrasound. Two-way ANOVA and multiple regression model were used.

Results

At late postmenopause, the carotid intima-media was thicker (p < 0.001) and flow-mediated dilatation decreased (p < 0.001). Carotid intima-media thickness was associated positively with age (p < 0.001), submission score (p = 0.029), follicle stimulating hormone levels (p < 0.001), and body mass index (p = 0.009). Flow-mediated dilatation was associated only with age (p < 0.001). Regarding heart rate variability, the time domain pNN50 measurement was higher in premenopausal women (p = 0.001), Low Frequency (LF) was higher in the two groups of postmenopausal (p = 0.001) and High Frequency (HF) higher in the early postmenopausal women (p = 0.042).

Conclusions

Under our conditions carotid intima-media thickness had higher predictive value for early cardiovascular damage at menopause. The finding of the association of the submission score, indicates de influence of stress on vascular damage.

Treatment with Standard and Low Dose of Conjugated Equine Estrogen Differentially Modulates Estrogen Receptor Expression and Response to Angiotensin II in Mesenteric Venular Bed of Surgically Postmenopausal Hypertensive Rats

Standard hormone therapy for menopausal women [conjugated equine estrogen (CEE) 0.625 mg] has been associated with increased risk of venous thrombosis. Regimens containing a lower CEE dose (0.30 mg) have been used clinically to decrease side effects of supraphysiologic doses of estrogen. In this study, we determined the effects of standard (SD) and low dose (LD) of CEE on venular function in ovariectomized (OVX) spontaneously hypertensive rats (SHR). Contractions by angiotensin-II (Ang-II 10 μM) in perfused mesenteric venular bed were markedly increased in OVX (21.5 ± 1.3 mmHg) compared with Sham (14.7 ± 1.1 mm Hg, P < 0.05). CEE-SD did not modify Ang-II responses in OVX, whereas CEE-LD restored Ang-II contraction to Sham levels. Endothelial nitric oxide synthase (eNOS) inhibition by L-NAME increased Ang-II contractions in Sham and CEE-LD and was without effect in venules of OVX SHR and CEE-SD. In OVX there was decreased NO generation in association with diminished eNOS phosphorylation and increased O2- generation in the venular wall. CEE-LD reverted the deleterious effects of ovariectomy. Although CEE-SD augmented eNOS phosphorylation in OVX, it was unable to increase NO levels, probably owing to its inability to reduce O2- Distinct effects by CEE-SD and CEE-LD parallel the differential modulation of Ang-II and estrogen receptors. Compared with Sham, CEE-LD increases Ang II receptor type 2, whereas CEE-SD modified ERβ expression in the venous bed. Interestingly, both CEE doses increased G protein-coupled estrogen receptor in OVX. Our data suggest that estrogen dose is an important factor for venous function. Although CEE-LD reversed deleterious effects of OVX, CEE-SD showed null effects despite its ability to increase eNOS activity.

ETB receptor contribution to vascular dysfunction in postmenopausal women

Endothelin-1 (ET-1) contributes to age-related endothelial dysfunction in men via the ET_A receptor. However, there are sex differences in the ET-1 system, and ET_B receptors are modulated by sex hormones. The purpose of this study was to test the hypothesis that ET_B receptors contribute to impaired vasodilatory function in postmenopausal women (PMW). We measured flow-mediated dilation (FMD) using ultrasound, and cutaneous nitric oxide-mediated vasodilation during local heating (42°C) via laser Doppler flowmetry in 18 young women (YW; 22 ± 1 yr) and 16 PMW (56 ± 1 yr). Cutaneous microdialysis perfusions of lactated Ringer (control), an ET_B receptor antagonist (BQ-788, 300 nM), and an ET_A receptor antagonist (BQ-123, 500 nM), were done through separate fibers, followed by perfusions of sodium nitroprusside (28 mM) and local heating to 43°C (max). Cutaneous vascular conductance (CVC) was calculated as cutaneous blood flow/mean arterial pressure and expressed as a percent of maximal dilation. FMD (YW: 7.5 ± 0.5 vs. PMW: 5.6 ± 0.6%) and cutaneous vasodilation (YW: 93 ± 2 vs. PMW: 83 ± 4%CVC_max) were lower in PMW (both P < 0.05). Blockade of ET_B receptors decreased cutaneous vasodilation in YW (87 ± 2%CVC_max; P < 0.05 vs. control) but increased vasodilation in PMW (93 ± 1%CVC_max; P < 0.05 vs. control). ET_A receptor blockade had minimal effect in YW (92 ± 1%CVC_max) but increased cutaneous vasodilation in PMW (91 ± 2%CVC_max; P < 0.05 vs. control). In conclusion, ET_B receptors mediate vasodilation in YW, but this effect is lost after menopause. Impaired vasodilatory function in PMW is due in part to a loss of ET_B-mediated dilation.

Vascular Adaptations to Habitual Exercise in Older Adults: Time for the Sex Talk

Regular exercise is promoted as a therapeutic strategy for age-associated endothelial dysfunction. Improvements in endothelial function are observed with endurance exercise in older men, but are diminished or absent in older women. This article examines the hypothesis that sex hormones modulate vascular adaptations to exercise training by influencing antioxidant defense systems, mitochondrial function, oxidative stress, and intracellular signaling.

Estrogens and Coronary Artery Disease: New Clinical Perspectives

In premenopausal women, endogenous estrogens are associated with reduced prevalence of arterial hypertension, coronary artery disease, myocardial infarction, and stroke. Clinical trials conducted in the 1990s such as HERS, WHI, and WISDOM have shown that postmenopausal treatment with horse hormone mixtures (so-called conjugated equine estrogens) and synthetic progestins adversely affects female cardiovascular health. Our understanding of rapid (nongenomic) and chronic (genomic) estrogen signaling has since advanced considerably, including identification of a new G protein-coupled estrogen receptor (GPER), which like the "classical" receptors ERα and ERβ is highly abundant in the cardiovascular system. Here, we discuss the role of estrogen receptors in the pathogenesis of coronary artery disease and review natural and synthetic ligands of estrogen receptors as well as their effects in physiology, on cardiovascular risk factors, and atherosclerotic vascular disease. Data from preclinical and clinical studies using nonselective compounds activating GPER, which include selective estrogen receptor modulators such as tamoxifen or raloxifene, selective estrogen receptor downregulators such as Faslodex™ (fulvestrant/ICI 182,780), vitamin B3 (niacin), green tea catechins, and soy flavonoids such as genistein or resveratrol, strongly suggest that activation of GPER may afford therapeutic benefit for primary and secondary prevention in patients with or at risk for coronary artery disease. Evidence from preclinical studies suggest similar efficacy profiles for selective small molecule GPER agonists such as G-1 which are devoid of uterotrophic activity. Further clinical research in this area is warranted to provide opportunities for future cardiovascular drug development.

Tributyltin chloride increases phenylephrine-induced contraction and vascular stiffness in mesenteric resistance arteries from female rats

Tributyltin chloride (TBT) is an organotin compound that reduces estrogen levels in female rats. We aimed to investigate the effects of TBT exposure on vascular tonus and vascular remodelling in the resistance arteries of female rats. Rats were treated daily with TBT (500 ng/kg) for 15 days. TBT did not change arterial blood pressure but did modify some morpho-physiological parameters of third-order mesenteric resistance arteries in the following ways: (1) decreased lumen and external diameters; (2) increased wall/lm ratio and wall thickness; (3) decreased distensibility and increased stiffness; (4) increased collagen deposition; and (5) increased pulse wave velocity. TBT exposure increased the phenylephrine-induced contractile response in mesenteric resistance arteries. However, vasodilatation responses induced by acetylcholine and sodium nitroprusside were not modified by TBT. It is suggested that TBT exposure reduces vascular nitric oxide (NO) production, because:(1) L-NAME incubation did not cause a leftward shift in the concentration-response curve for phenylephrine; (2) both eNOS protein expression; (3) in situ NO production were reduced. Incubation with L-NAME; and (4) SOD shifted the phenylephrine response curve to the left in TBT rats. Tiron, catalase, ML-171 and VAS2870 decreased vascular reactivity to phenylephrine only in TBT rats. Moreover, increased superoxide anion production was observed in the mesenteric resistance arteries of TBT rats accompanied by an increase in gp91phox, catalase, AT1 receptor and total ERK1/2 protein expression. In conclusion, these findings show that TBT induced alterations are most likely due to a reduction of NO production combined with increased O2(-) production derived from NADPH oxidase and ERK1/2 activation. These findings offer further evidence that TBT is an environmental risk factor for cardiovascular disease.

Decreased bioavailability of nitric oxide in aorta from ovariectomized senescent mice. Role of cyclooxygenase

This study investigates the effects of aging and/or ovariectomy on vascular reactivity to thromboxane A2 (TXA2) receptor stimulation with U46619, and the modulation by nitric oxide (NO) and cyclooxygenase (COX) in aorta from female senescence-accelerated mice (SAMP8) and from senescence resistant mice (SAMR1). Five-month-old female SAMR1 and SAMP8 were divided into three groups: sham-operated, ovariectomized and ovariectomized plus estradiol. Twenty-eight days after surgery, thoracic aortic rings were mounted for isometric recording of tension and concentration-response curves for U46619 (10(-10)-3 × 10(-7) M) were performed in the absence and in the presence of the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) and/or COX inhibitor indomethacin (10(-5)M). Vascular superoxide production was detected by dihydroethidium staining on sections of thoracic aorta. NO bioavailability in response to U46619 was suppressed by estrogen withdrawn in young and senescent mice and was restored by the administration of estradiol. In the presence of indomethacin, contractions to U46619 decreased in all groups indicating an aging- and estrogen-dependent modulation of contractile prostanoids. The simultaneous incubation of L-NAME and indomethacin did not change the maximal responses and sensitivities to TXA2 in any group in comparison with untreated aortic segments. The superoxide generation induced by TXA2 was greater in aorta from SAMP8 than in SAMR1. Moreover, in ovariectomized groups superoxide production was further increased and treatment with 17β-estradiol reverted the effects of the ovariectomy. Inhibition of COX with indomethacin prevented the U46619-induced increase in superoxide formation. Our results indicate that NO bioavailability in response to TP receptor activation is both estrogen- and aging-dependent. TXA2 induced contractions are partially mediated by COX activation. Both aging and ovariectomy enhanced COX-dependent component of the TXA2-induced contraction. It is noteworthy that in the absence of estrogen, COX inhibition induces an increase of NO bioavailability. Therefore, in senescent female mice with an experimental menopause, TP-receptor stimulation is responsible for COX activation and enhanced superoxide generation, which may result in reduced NO bioavailability. These effects were reversed by estrogen administration.

Premature Menopause

A heterogeneous disorder, premature menopause is not an uncommon entity, affecting approximately 1% of women younger than 40 years. Multisystem implications are recognized as sequelae to the premature deprivation of ovarian steroids, posing unique health-related challenges in this population. An integrated management approach that addresses both the physical and psychological health concerns and the overall well-being of this relatively chronologically young population is paramount.

Chronic black tea extract consumption improves endothelial function in ovariectomized rats

Purpose

Menopause escalates the risk of cardiovascular diseases in women. There is an unmet need for better treatment strategy for estrogen-deficiency-related cardiovascular complications. Here we investigated the impact of chronic black tea extract (BT) consumption on cardiovascular function and lipid metabolism using a rat model of estrogen deficiency.

Methods

Female Sprague–Dawley rats were ovariectomized (OVX) and treated with BT (15 mg/kg/day, 4 weeks; active ingredients: theaflavins) or estrogen (E2) treatment for 4 weeks. Serum was collected for measuring cholesterol, triacylglycerol and estradiol levels. Changes in vascular reactivity were examined. The protein levels of NADPH oxidases were assessed by Western blotting. Reactive oxygen species (ROS) level was measured using dihydroethidium fluorescence imaging. The concentrations of cGMP were measured using ELISA kit.

Results

Aortic rings from control, BT-treated and E2-treated OVX rats exhibited a greater increase in Phe-induced contraction after inhibition of NO synthase compared with those from OVX rats. ACh-induced endothelium-dependent relaxations were augmented in aortae and renal arteries in BT/E2-treated OVX rats than in OVX rats. BT/E2 treatment improved flow-mediated dilatation in small mesenteric resistance arteries of OVX rats. BT/E2 treatment restored the eNOS phosphorylation level and reversed the up-regulation of NADPH oxidases and ROS overproduction in OVX rat aortae. ACh-stimulated cGMP production was significantly elevated in the aortae from BT- and E2-treated rats compared with those from OVX rats. BT/E2 treatment reduced circulating levels of total cholesterol.

Conclusions

The present study reveals the novel benefits of chronic BT consumption to reverse endothelial dysfunction and favorably modifying cholesterol profile in a rat model of estrogen deficiency and provides insights into developing BT as beneficial dietary supplements for postmenopausal women.

Understanding the Role of Sex in Heart Valve and Major Vascular Diseases

Cardiovascular disease (CVD) is the major cause of mortality in the elderly population. The cost of CVD treatment and surgeries was over $300 billion in the United States alone in 2010, making this disorder a critical healthcare issue. Many studies have suggested sex as a risk factor for heart valve and major vascular diseases, such as aortic valve stenosis, mitral prolapse and regurgitation, atherosclerosis, coronary artery disease, and abdominal aortic aneurysm. Unfortunately, only a handful of studies have illustrated the role of sex in the etiology and progression of these disorders. Moreover, knowledge of biomolecular factors that affect these diseases in men and women is very limited. Numerous clinical studies have revealed obvious differences in the prevalence of these diseases between the sexes. These reports were supported by a few molecular and cellular physiology studies that associated this difference to sex and sex hormones. In particular, male sex has commonly been identified as a risk factor for majority of heart valve and vascular diseases, whereas females have been identified as higher risk for certain disorders as well. In addition, menopause is a critical issue that turns the tables against women and enhances complications in their cardiovascular structure due to hormonal change. In this review, major vascular and heart valve diseases for which sex is associated as a risk factor have been reviewed to highlight the importance of this risk factor in CVDs.

Effects of sex hormones on inflammatory response in male and female vascular endothelial cells

PURPOSE

Gender-related differences in sex hormones might have a key role in the development of atherosclerosis though direct vascular effects of sex hormones are not yet well understood. Thus, the main purpose of this study was to compare the effects of sex hormones on inflammatory response in Human Umbilical Vein Endothelial Cells (HUVECs) obtained from both male and female donors.

METHODS

We analyzed the expression of receptors and enzymes relevant to the action of androgens (AR, 5α-reductase 1 and 5α-reductase 2) and estrogens (ERα, ERβ, and aromatase) in male and female HUVECs. Furthermore, we analyzed the effect of testosterone (T), 17β-estradiol (E2), dihydrotestosterone (DHT), and several androgenic-anabolic steroids (AAS) on VCAM-1, ICAM-1, and E-selectin gene expression and on adhesion of U937 cells to TNF-α-stimulated male and female HUVECs.

RESULTS

Our results reveal that in HUVECs, regardless of gender, the components involved in the androgen action pathway are predominant as compared to those of estrogen action pathway. In both HUVEC genders, the inflammatory effect of TNF-α was amplified by co-administration of T or DHT and several AAS frequently used in doping, while E2 had no effect.

CONCLUSIONS

This is the first study analyzing, under identical culture conditions, the key components of sex hormone response in male and female HUVECs and the possible role of sex hormones in regulating the endothelial inflammatory response. The data obtained in our experimental system showed a pro-inflammatory effect of androgens, while conclusively excluding any protective effect for all the tested hormones.

Vascular Aging across the Menopause Transition in Healthy Women

Vascular aging, featuring endothelial dysfunction and large artery stiffening, is a major risk factor for developing cardiovascular disease (CVD). In women, vascular aging appears to be accelerated during the menopause transition, particularly around the late perimenopausal period, presumably related to declines in ovarian function and estrogen levels. The mechanisms underlying endothelial dysfunction and large artery stiffening with the menopause transition are not completely understood. Oxidative stress and the proinflammatory cytokine tumor necrosis factor-α contribute to endothelial dysfunction and large artery stiffening in estrogen-deficient postmenopausal women. Habitual endurance exercise attenuates the age-related increase in large artery stiffness in estrogen-deficient postmenopausal women and can reverse arterial stiffening to premenopausal levels in estrogen-replete postmenopausal women. In contrast, estrogen status appears to play a key permissive role in the adaptive response of the endothelium to habitual endurance exercise in that endothelial improvements are absent in estrogen-deficient women but present in estrogen-replete women. We review here the current state of knowledge on the biological defects underlying vascular aging across the menopause transition, with particular focus on potential mechanisms, the role of habitual exercise in preserving vascular health, and key areas for future research.

Ethanolic extract of rhizome of Ligusticum chuanxiong Hort. (chuanxiong) enhances endothelium-dependent vascular reactivity in ovariectomized rats fed with high-fat diet

Rhizome of Ligusticum chuanxiong Hort. (LC), also known as chuanxiong, is a very common herb widely used to treat cardiovascular and cerebrovascular diseases.

Endothelial relaxation mechanisms and oxidative stress are restored by atorvastatin therapy in ovariectomized rats

The studies on hormone replacement therapy (HRT) in females with estrogen deficiency are not conclusive. Thus, non-estrogen therapies, such as atorvastatin (ATO), could be new strategies to substitute or complement HRT. This study evaluated the effects of ATO on mesenteric vascular bed (MVB) function from ovariectomized (OVX) female rats. Female rats were divided into control SHAM, OVX, and OVX treated with 17β-estradiol (EST) or ATO groups. The MVB reactivity was determined in organ chambers, vascular oxidative stress by dihydroethidine staining, and the expression of target proteins by western blot. The reduction in acetylcholine-induced relaxation in OVX rats was restored by ATO or EST treatment. The endothelium-dependent nitric oxide (NO) component was reduced in OVX rats, whereas the endothelium-derived hyperpolarizing factor (EDHF) component or prostanoids were not altered in the MVBs. Endothelial dysfunction in OVX rats was associated with oxidative stress, an up-regulation of iNOS and NADPH oxidase expression and a down-regulation of eNOS expression. Treatment with ATO or EST improved the NO component of the relaxation and normalized oxidative stress and the expression of those signaling pathways enzymes. Thus, the protective effect of ATO on endothelial dysfunction caused by estrogen deficiency highlights a significant therapeutic benefit for statins independent of its effects on cholesterol, thus providing evidence that non-estrogen therapy could be used for cardiovascular benefit in an estrogen-deficient state, such as menopause.

Essential role of estrogen for improvements in vascular endothelial function with endurance exercise in postmenopausal women

OBJECTIVE

In contrast to age-matched men, endurance exercise training is not consistently associated with enhanced endothelial function in estrogen-deficient postmenopausal women. We determined whether endurance exercise training improves endothelial function in postmenopausal women treated with estrogen. In a substudy, we determined if oxidative stress is mechanistically linked to endothelial function adaptations to endurance exercise training.

PARTICIPANTS AND DESIGN

Brachial artery flow-mediated dilation (FMD) was measured in 36 sedentary, estrogen-deficient postmenopausal women (45-65 y) at study entry (baseline), after 12 weeks of either placebo, oral (1 mg/d) estradiol, or transdermal estradiol (0.05 mg/d) (randomized), and after an additional 12 weeks of continued estradiol or placebo treatment with concurrent endurance exercise training. In subgroups of women, FMD also was measured during the infusion of ascorbic acid at baseline and following estradiol/placebo plus endurance exercise training, and in seven habitually endurance-trained estrogen-deficient controls.

RESULTS

FMD increased in the estrogen-treated groups (both P < .01) after 12 weeks and remained unchanged in placebo. FMD further increased following 12 weeks of endurance exercise training in estrogen-treated (both P < .025), but not placebo-treated women (P = .55). In the substudy, baseline FMD was similar between sedentary and endurance-trained controls. Ascorbic acid increased FMD at baseline in sedentary women and endurance-trained controls, and following endurance exercise training in placebo-treated, but not in estrogen-treated women.

CONCLUSIONS

Estrogen status appears to play an important modulatory role in improvements in endothelial function with endurance exercise training in postmenopausal women. The restored endurance exercise training adaptation in estrogen-treated postmenopausal women may be related to mitigation of oxidative stress.

Tumor necrosis factor-α inhibition improves endothelial function and decreases arterial stiffness in estrogen-deficient postmenopausal women

OBJECTIVE

Tumor necrosis factor (TNF)-α, a pleiotropic pro-inflammatory cytokine involved in a variety of biological processes including oxidative stress, has been associated with vascular dysfunction in aged and ovariectomized animals. We determined whether acute inhibition of TNF-α improves vascular endothelial function and decreases arterial stiffness in estrogen-deficient postmenopausal women.

METHODS

Arterial stiffness (carotid artery compliance) and endothelial function (brachial artery flow-mediated dilation [FMD]) were measured in postmenopausal women (n = 23; 57 ± 1 years, mean ± SE) before and following randomization to two days of either transdermal estradiol (0.05 mg/d, N = 12) or placebo (N = 11) alone and following a single subcutaneous injection of the TNF-α inhibitor, etanercept (25 mg), and in premenopausal (n = 9; 33 ± 2 years) before and following etanercept.

RESULTS AND CONCLUSIONS

Baseline carotid artery compliance and brachial artery FMD were lower in postmenopausal than premenopausal women (P < 0.0001). In postmenopausal women, carotid artery compliance (n = 12; 0.59 ± 0.05-0.78 ± 0.06 mm(2)/mmHg × 10(-1), P < 0.001) and FMD (4.1 ± 0.6-6.0 ± 0.7%, P = 0.02) increased in response to estradiol but not placebo (n = 11). Carotid artery compliance (0.71 ± 0.06-0.81 ± 0.06 mm(2)/mmHg × 10(-1), P = 0.02) and FMD (5.2 ± 0.7-7.5 ± 0.9%, P = 0.003) increased with etanercept in the placebo group but had no effect in postmenopausal randomized to estradiol or premenopausal women. These results suggest that TNF-α contributes to impaired endothelial-dependent vasodilation and arterial stiffening in estrogen-deficient postmenopausal women.