Estrogen replacement and brachial artery flow-mediated vasodilation in older women

Pharmacological modulation of vascular ageing: A review from VascAgeNet

Vascular ageing, characterized by structural and functional changes in blood vessels of which arterial stiffness and endothelial dysfunction are key components, is associated with increased risk of cardiovascular and other age-related diseases. As the global population continues to age, understanding the underlying mechanisms and developing effective therapeutic interventions to mitigate vascular ageing becomes crucial for improving cardiovascular health outcomes. Therefore, this review provides an overview of the current knowledge on pharmacological modulation of vascular ageing, highlighting key strategies and promising therapeutic targets. Several molecular pathways have been identified as central players in vascular ageing, including oxidative stress and inflammation, the renin-angiotensin-aldosterone system, cellular senescence, macroautophagy, extracellular matrix remodelling, calcification, and gasotransmitter-related signalling. Pharmacological and dietary interventions targeting these pathways have shown potential in ameliorating age-related vascular changes. Nevertheless, the development and application of drugs targeting vascular ageing is complicated by various inherent challenges and limitations, such as certain preclinical methodological considerations, interactions with exercise training and sex/gender-related differences, which should be taken into account. Overall, pharmacological modulation of endothelial dysfunction and arterial stiffness as hallmarks of vascular ageing, holds great promise for improving cardiovascular health in the ageing population. Nonetheless, further research is needed to fully elucidate the underlying mechanisms and optimize the efficacy and safety of these interventions for clinical translation.

Cardiovascular Risk Factors in Premature Ovarian Insufficiency using Hormonal Therapy

OBJECTIVE

 Premature ovarian insufficiency (POI) is characterized by early hypoestrogenism. An increased risk of cardiovascular (CV) disease is a long-term consequence of POI. A challenge of hormone therapy (HT) is to reduce the CV risk.

METHODS

 Cross-sectional study with lipid profile analysis (total cholesterol, LDL-C, HDL-C, VLDL-C and triglycerides), blood glucose levels and arterial blood pressure of women with POI using HT, compared with age and BMI-matched women with normal ovarian function (controls).

RESULTS

 The mean age and BMI of 102 POI patients using HT and 102 controls were 37.2 ± 6.0 and 37.3 ± 5.9 years, respectively; 27.0 ± 5.2 and 27.1 ± 5.4 kg/m². There wasn't difference between groups in arterial systolic and diastolic blood pressure, blood glucose levels, total cholesterol, LDL-C, VLDL-C and triglycerides. HDL-C levels were significantly higher in the POI group (56.3 ± 14.6 and 52 ± 13.9mg/dL; p = 0.03). Arterial hypertension was the most prevalent chronic disease (12% in the POI group, 19% in the control group, p = ns), followed by dyslipidemia (6 and 5%, in POI and control women).

CONCLUSION

 Women with POI using HT have blood pressure levels, lipid and glycemic profile and prevalence of hypertension and dyslipidemia similar to women of the same age and BMI with preserved gonadal function, in addition to better HDL levels.

Brachial Flow-Mediated Dilation and Risk of Atrial Fibrillation in Older Adults: The Cardiovascular Health Study

Background

Endothelial dysfunction is associated with common risk factors for AF and has been implicated in the pathophysiology of atrial fibrillation (AF) through a variety of mechanisms. We determined the prospective association of brachial flow-mediated dilation (FMD) with incident AF among older adults.

Methods

We included 2027 Cardiovascular Health Study participants (mean age=78.3 years, male=39%, Black=17%) who underwent brachial FMD measurement at the 1997 to 1998 clinic visit. Incident AF was ascertained by study electrocardiograms, hospital discharge diagnosis coding and Medicare claims data. Cox regression models were used to examine the association between FMD and incident AF.

Results

We identified 754 incident of AF cases (37%) over a median follow-up of 11.0 years. After adjusting for age, sex, race, height, weight, cardiovascular disease, cigarette smoking, hypertension, diabetes, kidney function, c-reactive protein, physical activity, alcohol consumption, and statins, the risk of AF did not differ according to brachial FMD response (4th vs 1st quartile hazard ratio (HR)=1.01, 95% confidence interval (CI): 0.81, 1.26; per FMD unit increment HR=1.01, 95% CI: 0.97, 1.05).

Conclusion

We found no relationship between brachial FMD and the risk of developing AF in this elderly cohort. Our findings suggest that the utility of brachial FMD as a risk marker for AF in older individuals is minimal.

Is ovarian response associated with adverse perinatal outcomes in GnRH antagonist IVF/ICSI cycles?

RESEARCH QUESTION

Is there an association between ovarian response and perinatal outcomes?

DESIGN

A retrospective, single-centre cohort study including all women undergoing their first ovarian stimulation cycle in a gonadotrophin releasing hormone antagonist protocol, with a fresh embryo transfer that resulted in a singleton live birth from January 2009 to December 2015. Patients were categorized into four groups according to the number of oocytes retrieved: one to three (category 1), four to nine (category 2), 10-15 (category 3), or over 15 oocytes (category 4).

RESULTS

The overall number of patients analysed was 964. No relevant statistical difference was found among neonatal outcomes across the four ovarian response categories. Neonatal weight (in grams) was comparable between all groups (3222 ± 607 versus 3254 ± 537 versus 3235 ± 575 versus 3200 ± 622; P = 0.85, in categories 1, 2, 3 and 4, respectively). No statistically significant differences were found among the ovarian response categories for birth weight z-scores (taking into account neonatal sex and delivery term). The incidence of pre-term birth and low birth weight was comparable across the different ovarian response groups (P = 0.127 and P = 0.19, respectively). Finally, the occurrence of adverse obstetric outcomes did not differ among the ovarian response categories. Multivariate regression analysis revealed that the number of oocytes was not associated with neonatal birth weight.

CONCLUSIONS

No association was found between ovarian response and adverse perinatal outcomes in antagonist IVF and intracytoplasmic sperm injection cycles. Future, larger scale and prospectively designed investigations are needed to validate these results.

Impact of high sodium intake on blood pressure and functional sympatholysis during rhythmic handgrip exercise

High dietary sodium intake is a risk factor for arterial hypertension; given that the ability to overcome sympathetically mediated vasoconstriction (functional sympatholysis) is attenuated in individuals with hypertension, we investigated the cardiovascular responses to high salt (HS) intake in healthy humans. We hypothesized that a HS intake of 15 g/day for 7 days would attenuate functional sympatholysis and augment the blood pressure response to handgrip exercise (HGE). Thirteen participants (6 males, 7 females) underwent 2 individual days of testing. Beat-by-beat blood pressure and heart rate were recorded throughout the trial on the non-exercising limb. Forearm blood flow was derived from ultrasonography on the brachial artery of the exercising limb. Participants then underwent a flow-mediated dilation (FMD) test. Next, a submaximal HGE was performed for 7 min with lower body negative pressure initiated during minutes 5-7. A single spot urine sample revealed a significant increase in sodium excretion during the HS conditions (p < 0.01). FMD was reduced during the HS condition. Mean arterial pressure was significantly higher during HS intake. No alteration to functional sympatholysis was found between conditions (p > 0.05). In summary, HS intake increases blood pressure without impacting functional sympatholysis or blood pressure responsiveness during HGE. These findings indicate that brachial artery dysfunction precedes an inefficient functional sympatholysis. Novelty Functional sympatholysis was not impacted by 1 week of high sodium intake. High sodium intake augmented the rate pressure product during handgrip exercise in healthy humans.

Estrogen effects on arteries vary with stage of reproductive life and extent of subclinical atherosclerosis progression

The past several years have been marked by confusion and controversy concerning whether estrogens are cardioprotective. The issue is of utmost public health importance because coronary heart disease (CHD) remains the leading cause of death among postmenopausal women. Fortunately, a unifying hypothesis has emerged that reproductive stage is a major determinant of the effect of estrogens on atherosclerosis progression, complications, and plaque vulnerability.

PREMENOPAUSAL YEARS

Premenopausal atherosclerosis progression seems to be an important determinant of postmenopausal atherosclerosis and thus the risk for CHD. Clearly, plasma lipids/lipoproteins influence this progression; however, estradiol deficiency seems to be the major modulator. Both monkeys and women with premenopausal estrogen deficiency develop premature atherosclerosis, an effect that can be prevented in both species by estrogen-containing oral contraceptives.

PERIMENOPAUSAL/EARLY POSTMENOPAUSAL YEARS

During this stage, there are robust estrogen benefits. Monkeys given estrogens immediately after surgical menopause have a 70% inhibition in coronary atherosclerosis progression. Estrogen treatment prevented progression of atherosclerosis of women in the Estrogen in the Prevention of Atherosclerosis Trial. A meta-analysis of women younger than 60 years given hormone therapy had reduced total mortality (relative risk = 0.61, 95% CI: 0.39-0.95).

LATE POSTMENOPAUSAL YEARS

This stage is one in which there are no or possible deleterious estrogen effects. Monkeys lose CHD benefits of estrogens when treatment is delayed. The increase in CHD events associated with initiating hormone therapy 10 or more years after menopause seems to be related to up-regulation of the plaque inflammatory processes and plaque instability and may be down-regulated by statin pretreatment.

Differential Effect of Plasma Estradiol on Subclinical Atherosclerosis Progression in Early vs Late Postmenopause

CONTEXT

The Early vs Late Intervention Trial with Estradiol showed that hormone therapy (HT) reduced progression of atherosclerosis when initiated in early but not in late postmenopause.

OBJECTIVE

This posttrial analysis examined the association between plasma estradiol (E2) levels and atherosclerosis determined by rate of change in carotid artery intima-media thickness (CIMT) and tested whether this association is equally evident in early (<6 years) vs late (≥10 years) postmenopause.

DESIGN

Randomized controlled trial stratified by time since menopause (ClinicalTrials.gov no. NCT00114517). Mixed-effects linear models tested the association of E2 levels with CIMT rate of change.

SETTING

Los Angeles, California.

PARTICIPANTS

Healthy women in postmenopause.

INTERVENTION

Oral E2 with/without cyclic vaginal progesterone.

MAIN OUTCOME MEASURES

Plasma E2 levels and CIMT assessed every 6 months over an average of 4.8 years.

RESULTS

Among 596 women in postmenopause, higher E2 level was inversely associated with CIMT progression in those in early postmenopause (P = 0.041) and positively associated with CIMT progression in those in late postmenopause (P = 0.006) (P for interaction <0.001). CIMT progression rates for the lowest vs highest quartile of E2 levels among women in early postmenopause were 8.5 and 7.2 μm/y, respectively , whereas among women in late postmenopause they were 9.8 and 11.7 μm/y, respectively.

CONCLUSION

E2 levels were differentially associated with atherosclerosis progression according to timing of HT initiation. With higher E2 levels, CIMT progression rate was decreased among women in early postmenopause but increased among women in late postmenopause. These results support the timing hypothesis of HT initiation on cardiovascular benefit, with reduced atherosclerosis progression for initiation during early postmenopause.

Vascular Effects of Early versus Late Postmenopausal Treatment with Estradiol

BACKGROUND

Data suggest that estrogen-containing hormone therapy is associated with beneficial effects with regard to cardiovascular disease when the therapy is initiated temporally close to menopause but not when it is initiated later. However, the hypothesis that the cardiovascular effects of postmenopausal hormone therapy vary with the timing of therapy initiation (the hormone-timing hypothesis) has not been tested.

METHODS

A total of 643 healthy postmenopausal women were stratified according to time since menopause (<6 years [early postmenopause] or ≥10 years [late postmenopause]) and were randomly assigned to receive either oral 17β-estradiol (1 mg per day, plus progesterone [45 mg] vaginal gel administered sequentially [i.e., once daily for 10 days of each 30-day cycle] for women with a uterus) or placebo (plus sequential placebo vaginal gel for women with a uterus). The primary outcome was the rate of change in carotid-artery intima-media thickness (CIMT), which was measured every 6 months. Secondary outcomes included an assessment of coronary atherosclerosis by cardiac computed tomography (CT), which was performed when participants completed the randomly assigned regimen.

RESULTS

After a median of 5 years, the effect of estradiol, with or without progesterone, on CIMT progression differed between the early and late postmenopause strata (P=0.007 for the interaction). Among women who were less than 6 years past menopause at the time of randomization, the mean CIMT increased by 0.0078 mm per year in the placebo group versus 0.0044 mm per year in the estradiol group (P=0.008). Among women who were 10 or more years past menopause at the time of randomization, the rates of CIMT progression in the placebo and estradiol groups were similar (0.0088 and 0.0100 mm per year, respectively; P=0.29). CT measures of coronary-artery calcium, total stenosis, and plaque did not differ significantly between the placebo group and the estradiol group in either postmenopause stratum.

CONCLUSIONS

Oral estradiol therapy was associated with less progression of subclinical atherosclerosis (measured as CIMT) than was placebo when therapy was initiated within 6 years after menopause but not when it was initiated 10 or more years after menopause. Estradiol had no significant effect on cardiac CT measures of atherosclerosis in either postmenopause stratum. (Funded by the National Institute on Aging, National Institutes of Health; ELITE ClinicalTrials.gov number, NCT00114517.).

The effects of different hormone treatment on endothelial function in healthy postmenopausal women

We aimed to compare the effects of different types of hormone treatment (HT) on endothelial function by means of brachial artery ultrasonographic examination in postmenopausal women. Sixty-two healthy postmenopausal women were included in this study. Subjects were assigned to one of the five groups receiving 6 months of treatment [estrogen (conjugated estrogen), estrogen (conjugated estrogen) plus progesterone (medroxyprogesterone acetate; MPA), raloxifene, tibolone or control]. Endothelial function was assessed by measurement of flow-mediated dilatation (FMD) and nitrate-dependent dilatation in the brachial artery. At the end of 6 months, FMD values were found to be significantly increased in women with HT use than the control group (p = 0.001). In subgroups, FMD increased significantly in the estrogen [12 ± 7 versus 25 ± 8, p = 0.001] and raloxifene groups [7 ± 5 versus 11 ± 3, p < 0.01] compared to tibolone and estrogen plus progesterone groups. In conclusion, endothelial function is impaired in postmenopausal women. Both estrogen and raloxifene regimens may improve endothelial functions in healthy postmenopausal women. The direct protective effects of these HT on the healthy endothelium may be more remarkable than the favorable effects on lipid profile.

Vascular effects of estrogenic menopausal hormone therapy

Cardiovascular disease (CVD) is more common in men and postmenopausal women (Post-MW) than premenopausal women (Pre-MW). Despite recent advances in preventive measures, the incidence of CVD in women has shown a rise that matched the increase in the Post-MW population. The increased incidence of CVD in Post-MW has been related to the decline in estrogen levels, and hence suggested vascular benefits of endogenous estrogen. Experimental studies have identified estrogen receptor ERα, ERβ and a novel estrogen binding membrane protein GPR30 (GPER) in blood vessels of humans and experimental animals. The interaction of estrogen with vascular ERs mediates both genomic and non-genomic effects. Estrogen promotes endothelium-dependent relaxation by increasing nitric oxide, prostacyclin, and hyperpolarizing factor. Estrogen also inhibits the mechanisms of vascular smooth muscle (VSM) contraction including [Ca2+]i, protein kinase C and Rho-kinase. Additional effects of estrogen on the vascular cytoskeleton, extracellular matrix, lipid profile and the vascular inflammatory response have been reported. In addition to the experimental evidence in animal models and vascular cells, initial observational studies in women using menopausal hormonal therapy (MHT) have suggested that estrogen may protect against CVD. However, randomized clinical trials (RCTs) such as the Heart and Estrogen/ progestin Replacement Study (HERS) and the Women's Health Initiative (WHI), which examined the effects of conjugated equine estrogens (CEE) in older women with established CVD (HERS) or without overt CVD (WHI), failed to demonstrate protective vascular effects of estrogen treatment. Despite the initial set-back from the results of MHT RCTs, growing evidence now supports the 'timing hypothesis', which suggests that MHT could increase the risk of CVD if started late after menopause, but may produce beneficial cardiovascular effects in younger women during the perimenopausal period. The choice of an appropriate MHT dose, route of administration, and estrogen/progestin combination could maximize the vascular benefits of MHT and minimize other adverse effects, especially if given within a reasonably short time after menopause to women that seek MHT for the relief of menopausal symptoms.

Vascular effects and safety of dalcetrapib in patients with or at risk of coronary heart disease: the dal-VESSEL randomized clinical trial

AIMS

High-density lipoprotein cholesterol (HDL-C) is inversely associated with cardiovascular (CV) events and thus an attractive therapeutic target. However, in spite of marked elevations in HDL-C, the first cholesterol transport protein (CETP) inhibitor torcetrapib raised blood pressure (BP), impaired endothelial function, and increased CV mortality and morbidity. Dalcetrapib is a novel molecule acting on CETP with a different chemical structure to torcetrapib. As HDL stimulates nitric oxide (NO), suppresses inflammation, and exerts protective CV effects, we investigated the effects of dalcetrapib on endothelial function, blood pressure, inflammatory markers, and lipids in patients with, or at risk of, coronary heart disease (CHD) in a double-blind randomized placebo-controlled trial (clinicaltrials.gov number NCT00655538).

METHODS AND RESULTS

Patients with target low-density lipoprotein cholesterol (LDL-C) levels received dalcetrapib 600 mg/day or placebo for 36 weeks on top of standard therapy (including statins). The primary outcome measures were the change from baseline of flow-mediated dilatation (%FMD) of the right brachial artery after 5 min of cuff occlusion at 12 weeks and the 24 h ambulatory blood pressure monitoring (ABPM) at week 4. Secondary outcomes included change from baseline in FMD after 36 weeks and the change in ABPM at 12 and 36 weeks, changes in HDL-C, LDL-C, triglycerides, CETP activity, as well as standard safety parameters. Four hundred seventy-six patients were randomized. Baseline FMD was 4.1 ± 2.2 and 4.0 ± 2.4% with placebo or dalcetrapib, respectively and did not change significantly from placebo after 12 and 36 weeks (P = 0.1764 and 0.9515, respectively). After 4, 24, and 36 weeks of treatment with dalcetrapib, CETP activity decreased by 51, 53, and 56% (placebo corrected, all P < 0.0001), while at weeks 4, 12, and 36 HDL-C increased by 25, 27, and 31% (placebo corrected, all P < 0.0001). Low-density lipoprotein cholesterol levels did not change. At baseline, ABPM was 125 ± 12/74 ± 8mmHg in the placebo and 128 ± 11/75 ± 7mmHg in the dalcetrapib group (P = 0.3372 and 0.1248, respectively, placebo-corrected change from baseline) and did not change for up to 36 weeks. Biomarkers of inflammation, oxidative stress, and coagulation did not change during follow-up except for Lp-PLA(2) mass levels which increased by 17% (placebo corrected). Overall 7 patients given dalcetrapib and 8 patients given placebo experienced at least one pre-specified adjudicated event (11 events with dalcetrapib and 12 events with placebo).

CONCLUSION

The dal-VESSEL trial has established the tolerability and safety of CETP-inhibition with dalcetrapib in patients with or at risk of CHD. Dalcetrapib reduced CETP activity and increased HDL-C levels without affecting NO-dependent endothelial function, blood pressure, or markers of inflammation and oxidative stress. The dal-OUTCOMES trial (NCT00658515) will show whether dalcetrapib improves outcomes in spite of a lack of effect on endothelial function.

Progesterone enhances vascular endothelial cell migration via activation of focal adhesion kinase

The mechanisms of progesterone on endothelial cell motility are poorly investigated. Previously we showed that progesterone stimulated endothelial cell migration via the activation of actin-binding protein moesin, leading to actin cytoskeleton remodelling and the formation of cell membrane structures required for cell movement. In this study, we investigated the effects of progesterone on the formation of focal adhesion complexes, which provide anchoring sites for cell movement. In cultured human umbilical endothelial cells, progesterone enhanced focal adhesion kinase (FAK) phosphorylation at Tyr(397) in a dose- and time-dependent manner. Several signalling inhibitors interfered with progesterone-induced FAK activation, including progesterone receptor (PR) antagonist ORG 31710, specific c-Src kinase inhibitor PP2, phosphatidylinosital-3 kinase (PI3K) inhibitor wortmannin as well as ρ-associated kinase (ROCK-2) inhibitor Y27632. It suggested that PR, c-Src, PI3K and ROCK-2 are implicated in this action. In line with this, we found that progesterone rapidly promoted c-Src/PI3K/Akt activity, which activated the small GTPase RhoA/ρ-associated kinase (ROCK-2) complex, resulting in FAK phosphorylation. In the presence of progesterone, endothelial cells displayed enhanced horizontal migration, which was reversed by small interfering RNAs abrogating FAK expression. In conclusion, progesterone promotes endothelial cell movement via the rapid regulation of FAK. These findings provide new information on the biological actions of progesterone on human endothelial cells that are relevant for vascular function.

Sex hormones, aging, and Alzheimer's disease

A promising strategy to delay and perhaps prevent Alzheimer's disease (AD) is to identify the age-related changes that put the brain at risk for the disease. A significant normal age change known to result in tissue-specific dysfunction is the depletion of sex hormones. In women, menopause results in a relatively rapid loss of estradiol and progesterone. In men, aging is associated with a comparatively gradual yet significant decrease in testosterone. We review a broad literature that indicates age-related losses of estrogens in women and testosterone in men are risk factors for AD. Both estrogens and androgens exert a wide range of protective actions that improve multiple aspects of neural health, suggesting that hormone therapies have the potential to combat AD pathogenesis. However, translation of experimental findings into effective therapies has proven challenging. One emerging treatment option is the development of novel hormone mimetics termed selective estrogen and androgen receptor modulators. Continued research of sex hormones and their roles in the aging brain is expected to yield valuable approaches to reducing the risk of AD.

Sex hormones, aging, and Alzheimer's disease

A promising strategy to delay and perhaps prevent Alzheimer's disease (AD) is to identify the age-related changes that put the brain at risk for the disease. A significant normal age change known to result in tissue-specific dysfunction is the depletion of sex hormones. In women, menopause results in a relatively rapid loss of estradiol and progesterone. In men, aging is associated with a comparatively gradual yet significant decrease in testosterone. We review a broad literature that indicates age-related losses of estrogens in women and testosterone in men are risk factors for AD. Both estrogens and androgens exert a wide range of protective actions that improve multiple aspects of neural health, suggesting that hormone therapies have the potential to combat AD pathogenesis. However, translation of experimental findings into effective therapies has proven challenging. One emerging treatment option is the development of novel hormone mimetics termed selective estrogen and androgen receptor modulators. Continued research of sex hormones and their roles in the aging brain is expected to yield valuable approaches to reducing the risk of AD.

Hormones, heart disease, and health: individualized medicine versus throwing the baby out with the bathwater

It is increasingly axiomatic that depression has widespread adverse physiological effects and, conversely, that a variety of physiological systems impact the risk for developing depression. This convergence of depression and altered physiology is particularly dramatic during midlife--a time during which reproductive failure presages dramatic increases in prevalence of both heart disease and depression. The potentially meaningful and illuminating links between estrogen deficiency, cardiovascular disease (CVD), and depression have largely been obscured, first by assertions, subsequently repudiated, that the perimenopause was not a time of increased risk of depression, and more recently by the denegration of hormone replacement therapy by initial reports of the Women's Health Initiative. Increasingly, however, research has led to unavoidable conclusions that CVD and depression share common, mediating pathogenic processes and that these same processes are dramatically altered by the presence or absence of estrogen (E2). This review summarizes data supporting these contentions with the intent of placing depression and estrogen therapy in their proper physiologic context.

Aging and vascular endothelial function in humans

Advancing age is the major risk factor for the development of CVD (cardiovascular diseases). This is attributable, in part, to the development of vascular endothelial dysfunction, as indicated by reduced peripheral artery EDD (endothelium-dependent dilation) in response to chemical [typically ACh (acetylcholine)] or mechanical (intravascular shear) stimuli. Reduced bioavailability of the endothelium-synthesized dilating molecule NO (nitric oxide) as a result of oxidative stress is the key mechanism mediating reduced EDD with aging. Vascular oxidative stress increases with age as a consequence of greater production of reactive oxygen species (e.g. superoxide) without a compensatory increase in antioxidant defences. Sources of increased superoxide production include up-regulation of the oxidant enzyme NADPH oxidase, uncoupling of the normally NO-producing enzyme, eNOS (endothelial NO synthase) (due to reduced availability of the cofactor tetrahydrobiopterin) and increased mitochondrial synthesis during oxidative phosphorylation. Increased bioactivity of the potent endothelial-derived constricting factor ET-1 (endothelin-1), reduced endothelial production of/responsiveness to dilatory prostaglandins, the development of vascular inflammation, formation of AGEs (advanced glycation end-products), an increased rate of endothelial apoptosis and reduced expression of oestrogen receptor α (in postmenopausal females) also probably contribute to impaired EDD with aging. Several lifestyle and biological factors modulate vascular endothelial function with aging, including regular aerobic exercise, dietary factors (e.g. processed compared with non-processed foods), body weight/fatness, vitamin D status, menopause/oestrogen deficiency and a number of conventional and non-conventional risk factors for CVD. Given the number of older adults now and in the future, more information is needed on effective strategies for the prevention and treatment of vascular endothelial aging.

Hormones, heart disease, and health: individualized medicine versus throwing the baby out with the bathwater

It is increasingly axiomatic that depression has widespread adverse physiological effects, and conversely that a variety of physiological systems impact the risk for developing depression. This convergence of depression and altered physiology is particularly dramatic during midlife-a time during which reproductive failure presages dramatic increases in prevalence of both heart disease and depression. The potentially meaningful and illuminating links between estrogen (E2) deficiency, cardiovascular disease (CVD), and depression have largely been obscured, first by assertions, subsequently repudiated that the perimenopause was not a time of increased risk of depression, and more recently by the denegration of hormone replacement therapy by initial reports of the Women's Health Initiative. Increasingly, however, research has led to unavoidable conclusions that CVD and depression share common and mediating pathogenic processes and that these same processes are dramatically altered by the presence or absence of E2. This review summarizes data supporting this contention with the intent of placing depression and E2 therapy in their proper physiologic context.

Depot-medroxyprogesterone acetate and endothelial function before and after acute oral, vaginal, and transdermal estradiol treatment

Young women using depot-medroxyprogesterone acetate (DMPA) contraception have low circulating estrogen and elevated synthetic progestin. Low estrogen and certain progestins have been shown to impact endothelial function even in young healthy women. The purpose of this study was to investigate how DMPA affects endothelial function and serum biomarkers of cardiovascular risk before and after acute oral, vaginal, and transdermal estradiol treatments. Seven young women participated on 3 study days during a normal 12-week DMPA cycle, during weeks 3, 6, and 9. An additional 8 young women participated on 6 separate days during a 12-week DMPA cycle, 3 times on DMPA only and 3 times when using DMPA plus acute estradiol treatments. Wall tracking of high-resolution ultrasound images of the brachial artery were used during endothelium-dependent flow-mediated dilation and nitroglycerin administration to test endothelial function. Serum samples were analyzed for cardiovascular indexes at each study visit. All of the estradiol treatments increased endothelium-dependent flow-mediated dilation compared with DMPA only (P<0.001). Endothelium-dependent flow-mediated dilation was not different among DMPA-only treatment days. Endothelium-independent vasodilation and cholesterol levels were unchanged across DMPA-only and DMPA plus estradiol cycles. These data suggest that acute estradiol treatments improve endothelium-dependent flow-mediated dilation in young hypoestrogenic women using DMPA.

Oral contraceptive use, iron stores and vascular endothelial function in healthy women

BACKGROUND

Increased iron stores are associated with greater cardiovascular risk in postmenopausal women. Oral contraceptive pill (OCP) use decreases the volume of menstrual blood loss and increases iron stores, but the link between OCP use, iron stores and cardiovascular risk in premenopausal women has not been characterized.

STUDY DESIGN

We conducted a cross-sectional study of 23 healthy OCP users to determine the association between type and duration of OCP exposure, iron stores, and vascular endothelial function [flow-mediated dilation (FMD) in the brachial artery].

RESULTS

Median duration of OCP use was 45 months. FMD in the brachial artery was significantly associated with progestin type used (estranes/gonanes vs. drospirenone) and duration of OCP use (both p<.05) but not iron stores. In multivariate analysis, progestin type was the only independent predictor of FMD.

CONCLUSIONS

Use of OCP containing drospirenone was independently associated with greater FMD in the brachial artery and, thus, a potentially more favorable cardiovascular risk profile, when compared with use of OCP containing estranes/gonanes.

Characterization of an animal model of postmenopausal cardiac hypertrophy and novel mechanisms responsible for cardiac decompensation using ovariectomized pressure-overloaded rats

OBJECTIVE

The development of animal models of cardiovascular disease are critical to define pathophysiological mechanisms and to advance diagnosis and therapy. The lack of a suitable animal model represents a failure to define the mechanisms responsible for postmenopausal myocardial hypertrophy in hypertension and adverse cardiac remodeling.

METHODS

In this review, we presented a rat model of postmenopausal myocardial hypertrophy, with particular focus on the similarities between the animal model and postmenopausal women regarding myocardial function as well as molecular and subcellular mechanisms. To elucidate the molecular mechanism of left ventricular (LV) hypertrophy and remodeling in postmenopausal women, we analyzed myocardial hypertrophy as well as cardiac function and hypertrophy-related protein expression in ovariectomized (OVX) and pressure overloaded (PO) rats.

RESULTS

The model is characterized by depletion of serum estrogen and increased heart-to-body weight and lung-to-body weight ratios. Moreover, the OVX-PO rats also show increased mean arterial blood pressure, LV end-diastolic pressure, LV developed pressure, and maximal rates of LV contraction and relaxation compared with the OVX group. Importantly, Akt activity was largely attenuated, and both endothelial nitric oxide synthase expression and activity were markedly reduced in the OVX-PO group. Finally, significant increased mortality was observed in the OVX-PO group after chronic isoproterenol administration.

CONCLUSIONS

Our results demonstrate that rats subject to OVX are unable to compensate for hypertrophy partly due to impaired Akt-endothelial nitric oxide synthase signaling along with deteriorated heart function and demonstrated increased mortality. In this review, we discussed the mechanisms of cardiac injury, which could play a critical role in postmenopausal hypertrophy, as well as the characteristics of the OVX-PO female rats as a model to test cardioprotective drugs in postmenopausal women.

Submaximal exercise coronary artery flow increases in postmenopausal women without coronary artery disease after estrogen and atorvastatin

OBJECTIVE

The aim of this study was to determine the effect of statins and hormone therapy on submaximal exercise-induced coronary artery blood flow in postmenopausal women without a history of coronary artery disease. Hormone therapy or statin therapy in early postmenopausal women without coronary artery disease has been shown to enhance arterial endothelial function; we hypothesized that these agents would improve submaximal exercise-induced coronary artery blood flow.

METHODS

Sixty-four postmenopausal women, aged 50 to 65 years without documented coronary artery disease, were randomized in a double-blind, crossover fashion to receive 8 weeks of hormone therapy versus placebo, with or without 80 mg/day of atorvastatin. Before receipt of any therapy and after each treatment period, each woman underwent measures of coronary artery blood flow at rest and stress.

RESULTS

The combination of hormone therapy and atorvastatin increased submaximal exercise-induced coronary artery blood flow (P = 0.04). In the subgroups of women compliant with treatment, resting coronary artery blood flow increased in those receiving hormone therapy (P = 0.03) or statin therapy (P = 0.02).

CONCLUSIONS

In postmenopausal women aged 50 to 65 years without documented coronary artery disease, resting and submaximal exercise-induced coronary artery blood flow improves after receipt of high-dose atorvastatin and conjugated estrogens therapy.

Is brachial artery flow-mediated dilation associated with negative affect?

BACKGROUND

Trait negative affect has been implicated as a risk marker for cardiovascular disease, but the mechanisms underlying this association are uncertain.

PURPOSE

Our aim was to examine associations between trait measures of anger, hostility, depression, and anxiety with endothelial dysfunction via brachial artery flow-mediated dilation (FMD), an early indicator of cardiovascular disease.

METHOD

FMD was examined in 332 healthy older adults. Measures included Beck Anxiety and Depression Inventories, Cook-Medley Hostility Scale, and Spielberger State-Trait Anger Expression Inventory (Anger In, Anger Out, and Trait Anger).

RESULTS

Mean age was 60.5 +/- 4.8 years; 83% of participants were Caucasian and 49% were female. FMD was greater in women compared to men (6.17% vs. 4.07%, p < 0.001). Women reported significantly greater Anxiety (p < 0.001), and men reported greater Hostility (p = 0.004). In separate multivariable linear regression models controlling for cardiovascular risk factors, plus current hormone therapy for women, smaller FMD was associated with higher Anger In for women (beta = -0.222, p = 0.04) and showed a trend with higher Hostility for men (beta = -0.082, p = 0.09).

CONCLUSION

Endothelial dysfunction, as indicated by less vasodilatation of the brachial artery, is positively associated with measures of hostility and anger suppression in healthy older adults. Thus, associations between negative affect and cardiovascular health may be apparent early in the disease process.

Hormone replacement therapy and cardioprotection: a new dawn? A statement of the Study Group on Cardiovascular Disease in Women of the Italian Society of Cardiology on hormone replacement therapy in postmenopausal women

Cardiovascular disease is the leading cause of death in women in Western countries. Despite preventive strategies, in the past decades the incidence of cardiovascular events has shown a decline in men but a rise in women, matching the growth of the population of postmenopausal women. Several epidemiological findings suggest the causative pathophysiological role of ovarian hormone deficiency in the development of cardiovascular disease in women. Observational and randomized studies have suggested that hormone replacement therapy in early postmenopause could be beneficial from a cardiovascular point of view. Conversely, aging, time since menopause and presence of cardiovascular risk factors or cardiovascular disease may decrease its efficacy and increase the risk of cardiovascular events. It is plausible that the unfavorable effects of the estrogen/progestin combination used in the randomized studies are not related to the hormone preparation per se but rather to the use of hormones in the less receptive group of women, older and with cardiovascular risk factors. Clinical judgment, choice of the right dose and estrogen/progestin combination are of pivotal importance to maximize the beneficial effect of estrogen replacement therapy/hormone replacement therapy, especially if given within a reasonable time after the menopause to women who need the therapy for the relief of menopausal symptoms.

Relationship of urinary cGMP excretion with aging and menopausal status in a general population

AIM

Aging and postmenopausal women are associated with increased risks of cardiovascular disease; however, epidemiological evidence concerning the relationship of aging and the menopause with vascular biological activity is limited.

METHODS

We investigated the relationship of aging and the menopause with urinary excretion of cyclic guanosine 3',5' monophosphate (cGMP) in 1,541 Japanese men and women aged 40 to 79 years. The 24-hour urinary excretion of cGMP was measured with a (125)I-labeled cGMP radioimmunoassay and was adjusted for urinary creatinine excretion (nmol/mmol creatinine).

RESULTS

Aging was positively associated with urinary excretion of cGMP for both sexes. Postmenopausal women excreted significantly less urinary cGMP than premenopausal women after adjustment for age and other cardiovascular risk factors: 48.3+/-0.04 nmol/mmol vs. 61.5+/-0.07 nmol/mmol, p=0.006.

CONCLUSIONS

Our data suggest that cGMP-related vasodilatation is impaired in postmenopausal women.

Effects in postmenopausal women of estradiol and medroxyprogesterone alone and combined on resistance artery function and endothelial morphology and movement

CONTEXT

Endothelial dysfunction in resistance arteries after menopause is important for the development of high blood pressure and cardiovascular disease.

OBJECTIVES

Our objectives were to study the effects of different hormone replacement therapies on the function and morphology of isolated resistance arteries, and to look for their mechanistic basis.

DESIGN AND SETTING

This was a randomized, placebo-controlled double-blind study in a University hospital, along with laboratory based studies.

PATIENTS AND INTERVENTIONS

We isolated resistance arteries in sc biopsies from 55 postmenopausal women before and after 3-month therapy with estradiol (E2), medroxyprogesterone acetate (MPA), E2 plus MPA, or placebo. In addition, we studied isolated human endothelial cells.

MAIN OUTCOME MEASURES AND RESULTS

Artery flow-mediated dilatation was augmented after treatment with E2 or E2 plus MPA, whereas MPA or placebo had no effect. Pressure-induced myogenic tone was reduced by E2 plus MPA, whereas it was unchanged in the other groups. Scanning microscopy showed that E2 improved endothelial cell morphology and decreased signs of endothelial apoptosis, but the addition of MPA impaired these events. E2, MPA, or the combination all increased the expression and phosphorylation of the actin-binding protein, moesin and of the focal adhesion complex controller, focal adhesion kinase, and induced the rearrangement of cytoskeletal actin and vinculin fibers. All treatments promoted endothelial cell horizontal migration, with E2 inducing the strongest effect.

CONCLUSIONS

This study suggests that hormone replacement therapy with estrogens or in combination with MPA may benefit the function of resistance arteries and may preserve the morphological integrity of endothelial cells by regulatory actions on the cytoskeleton.

Relationship between brachial flow-mediated dilation and carotid intima-media thickness in an elderly cohort: the Cardiovascular Health Study

OBJECTIVE

The aim of this study was to determine the relationship between brachial flow-mediated dilation (FMD) and carotid intima-media thickness (IMT) in a large multi-ethnic elderly cohort.

BACKGROUND

Brachial flow-mediated dilation (FMD) is a physiologic measure and carotid IMT is an anatomic structural measure of subclinical atherosclerosis. Both brachial FMD and carotid IMT have been associated with cardiovascular risk factors and cardiovascular events. The relationship between brachial FMD and carotid IMT is less clear especially in older adults.

METHODS

Brachial FMD, carotid IMT and traditional cardiovascular risk factors were measured in 2338 adults, age 72-98 years who were participants in the Cardiovascular Health Study. The relationship between FMD and IMT was assessed both unadjusted and also after adjusting for age, gender and race/ethnicity, BMI, HDL, LDL, systolic and diastolic blood pressure, serum creatinine, current smoking, diabetes mellitus, hormone therapy and prior CVD.

RESULTS

Both brachial FMD and carotid IMT correlated significantly with age, HDL levels, waist/hip ratio, serum cholesterol and number of CV risk factors. Brachial FMD was not associated with CCA IMT in this elderly cohort (Pearson partial correlation coefficient=-0.0252, p=0.222). In the adjusted linear regression model with CCA IMT as the dependent variable, brachial FMD was also not associated with CCA IMT (beta coefficient=-0.006, p=0.470).

CONCLUSION

Brachial FMD and CCA IMT are not related in population-based older adults. Brachial FMD and CCA IMT may be distinct and independent stages in the complex atherosclerotic process.

Association between brachial artery reactivity and cardiovascular disease status in an elderly cohort: the cardiovascular health study

BACKGROUND AND OBJECTIVES

The association of brachial flow-mediated dilation (FMD) and cardiovascular disease (CVD) status is unclear especially in older adults whose FMD is greatly diminished. We assessed the association of FMD and the presence or absence of subclinical and clinical CVD in a population based cohort of older adults.

METHODS AND RESULTS

FMD was measured in 2971 adults aged 72-98 years (mean age 78.6 years) who participated in the Cardiovascular Health Study. Multiple linear regression analysis was used to examine the association between FMD and CVD status (clinical, subclinical and free of CVD). Out of 2791 with complete data, 82.7% were Caucasians and 59% females. Seven hundred and forty-three were classified as having clinical CVD, 607 as subclinical CVD and 1441 as neither clinical CVD nor subclinical CVD (CVD free). FMD was higher in the CVD free group compared with either the clinical (3.13+/-0.05% vs 2.93+/-0.07%, p=0.025) or the subclinical CVD group (3.13+/-0.05% vs 2.95+/-0.08%, p=0.05) after adjusting for covariates. There was no significant difference between the FMD of subjects with clinical and subclinical CVD (2.93+/-0.07% vs 2.95+/-0.08%, p=0.84). Similar but inverted associations were observed between height adjusted brachial artery diameter (BAD) and CVD status. However, FMD and BAD had poor diagnostic accuracies for identifying older adults with subclinical CVD.

CONCLUSION

Among older adults, those with either clinical or subclinical CVD have lower FMD than CVD free subjects. BAD showed similar but inverted associations with CVD status in this cohort. FMD and BAD had poor diagnostic accuracies for identifying older adults with subclinical CVD.

Estrogen effects on arteries vary with stage of reproductive life and extent of subclinical atherosclerosis progression

The past several years have been marked by confusion and controversy concerning whether estrogens are cardioprotective. The issue is of utmost public health importance because coronary heart disease (CHD) remains the leading cause of death among postmenopausal women. Fortunately, a unifying hypothesis has emerged that reproductive stage is a major determinant of the effect of estrogens on atherosclerosis progression, complications, and plaque vulnerability. PREMENOPAUSAL YEARS: Premenopausal atherosclerosis progression seems to be an important determinant of postmenopausal atherosclerosis and thus the risk for CHD. Clearly, plasma lipids/lipoproteins influence this progression; however, estradiol deficiency seems to be the major modulator. Both monkeys and women with premenopausal estrogen deficiency develop premature atherosclerosis, an effect that can be prevented in both species by estrogen-containing oral contraceptives. PERIMENOPAUSAL/EARLY POSTMENOPAUSAL YEARS: During this stage, there are robust estrogen benefits. Monkeys given estrogens immediately after surgical menopause have a 70% inhibition in coronary atherosclerosis progression. Estrogen treatment prevented progression of atherosclerosis of women in the Estrogen in the Prevention of Atherosclerosis Trial. A meta-analysis of women younger than 60 years given hormone therapy had reduced total mortality (relative risk = 0.61, 95% CI: 0.39-0.95). LATE POSTMENOPAUSAL YEARS: This stage is one in which there are no or possible deleterious estrogen effects. Monkeys lose CHD benefits of estrogens when treatment is delayed. The increase in CHD events associated with initiating hormone therapy 10 or more years after menopause seems to be related to up-regulation of the plaque inflammatory processes and plaque instability and may be down-regulated by statin pretreatment.

Raloxifene improves the ovariectomy-induced impairment in endothelium-dependent vasodilation

OBJECTIVE

To examine the effect of raloxifene on the endothelial dysfunction caused by surgical menopause.

DESIGN

Ten premenopausal women who underwent gynecological surgery with ovariectomy were divided into two groups. Five participants used raloxifene (60 mg/d) for 7 days staring 1 week after the surgery, and the other five participants did not use raloxifene. We examined the changes in flow-mediated dilatation (FMD) of the brachial artery using ultrasonography. Vasodilation in response to nitroglycerin was also studied. We also measured the brachial-ankle pulse wave velocity to examine the change in arterial stiffness in these participants before and after surgical menopause.

RESULTS

In both the raloxifene and control groups, a significant decrease in FMD was observed 1 week after the surgery. Although no further changes in FMD were observed in the control group at 2 weeks after surgery, FMD was significantly increased in the raloxifene group. No remarkable changes in nitroglycerin or brachial-ankle pulse wave velocity were observed after surgery in either group.

CONCLUSIONS

Raloxifene rapidly restored FMD that was impaired after surgical menopause. Therefore, raloxifene may be effective for ameliorating and maintaining endothelial function in premenopausal women who undergo ovariectomy.

Hormonal therapy: does it increase or decrease cardiovascular risk?

The use of hormonal therapy (HT) has become one of the most controversial topics in the area of women's health. A particular area of confusion has been the issue of cardiovascular benefit versus cardiovascular risk for women using HT. Although years of observational data have suggested that women receiving HT have a lower incidence of coronary artery disease (CAD) and longer survival, several prospective, randomized controlled trials have brought this tenet into debate. This article provides a historical perspective on the role of HT and CAD. The Heart and Estrogen/Progestin Replacement Study (HERS) and the Women's Health Initiative (WHI) data are analyzed in conjunction with newer data. Finally, an explanation will be provided as to how early initiation of HT could afford cardiovascular protection and not contradict the HERS and WHI.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to state that controversy still remains in the use of hormonal therapy (HT) for menopause, explain that there are conflicting data from both prospective and observational studies, and recall that a new look at prospective data may indicate that HT has beneficial cardiovascular effects.

Endothelial function across an oral contraceptive cycle in women using levonorgestrel and ethinyl estradiol

Oral contraceptive pills (OCPs) are a popular contraception method. Currently, lower-dose ethinyl estradiol formulations are most commonly prescribed, although they have been linked to increased arterial vascular risk. The aim of this study was to investigate endothelial function in healthy young women using lower-dose ethinyl estradiol OCPs. We examined flow-mediated, endothelium-dependent and nitroglycerin-mediated, endothelium-independent vasodilation of the brachial artery, comparing two doses of ethinyl estradiol/levonorgestrel OCPs in 15 healthy young women on two study days: once during the active phase and once during the placebo phase of an OCP cycle. Group low dose (LD) ( n = 7) active pills contained 150 μg levonorgestrel/30 μg ethinyl estradiol versus Group very low dose (VLD) ( n = 8) with 100 μg levonorgestrel/20 μg ethinyl estradiol. Endothelium-dependent vasodilation was lower during the active phase in Group VLD (5.33 ± 1.77% vs. 7.23 ± 2.60%; P = 0.024). This phase difference was not observed in Group LD (8.00 ± 0.970% vs. 7.61 ± 1.07%; P = 0.647). Endothelium-independent vasodilation did not differ between phases in either group. Finally, we measured endothelium-dependent vasodilation in two additional women who received 10 μg of unopposed ethinyl estradiol. Endothelium-dependent vasodilation was increased by unopposed ethinyl estradiol compared with the placebo phase (10.88 ± 2.34% vs. 6.97 ± 1.83%). These results suggest that levonorgestrel may antagonize the activity of ethinyl estradiol. Thus both the progestin type and estradiol dose need to be considered when assessing arterial vascular risk of OCP use in women.

Pitfalls of the WHIs: Women's Health Initiative

Recently, the use of hormone replacement therapy (HRT) at menopause has become a matter of debate. Its utility has been questioned after the publication of the results of the Women's Health Initiative (WHI) studies. This trial was divided in two arms of which the first examined the use of combined HRT (continuous estrogens plus progestins) and the second the use of estrogens alone in menopausal women. The first arm was terminated prematurely at 5.2 years because the number of cases of coronary heart disease (CHD), strokes, venous thromboembolic disease, and breast cancer were more in women receiving HRT than in women receiving placebo, if the nominal confidence intervals (CIs) were taken into account. However, in the same study the authors made clear that the adjusted CIs should be taken into account instead of the nominal ones. These latter ones caused the ending of the trial. Moreover, WHI was criticized for its conclusions as far as cardiovascular disease is concerned because of serious defects regarding design of the trial. If the adjusted CIs were taken into account then the increase in adverse events was significant only for deep vein thrombosis. The second arm demonstrated that the use of estrogens was not correlated to an increase of neither breast cancer incidence nor cardiovascular disease. A closer look at the results of the WHI trial reveals that the use of HRT for 5 years should not be considered deleterious for the appearance of breast cancer, cardiovascular diseases, strokes, and pulmonary embolisms. We suggest that HRT should be given early in menopause. The regimen should be individualized for each patient. More intense follow-up should be offered to women with a positive family history of breast cancer, diagnosed coronary disease, and to women with a predisposition to deep venous thrombosis.

Effects of estrogen replacement with and without medroxyprogesterone acetate on brachial flow-mediated vasodilator responses in postmenopausal women with coronary artery disease

BACKGROUND

Hormone therapy has been shown to have no cardioprotective effect and may, in fact, be harmful in older postmenopausal women. Estrogen has been shown to enhance endothelial-dependent flow-mediated vasodilation (FMD) in healthy and younger women. The effect of estrogen on older and less healthy postmenopausal women with atherosclerosis is unclear.

METHODS

The Estrogen Replacement and Atherosclerosis trial randomized 309 postmenopausal women with established coronary atherosclerosis (mean, 65.8 years) to unopposed estrogen (conjugated estrogen, 0.625 mg), estrogen plus 2.5 mg medroxyprogesterone actate (MPA), or placebo. After mean of 3.2 years of follow-up, brachial FMD was measured using 2-dimensional ultrasound in women available for follow-up at 4 of the 5 clinic sites (n = 198).

RESULTS

The %FMD of the brachial artery was not statistically different in the placebo arm compared with either unopposed estrogen or estrogen + MPA arm in both the adjusted and the unadjusted models. Subsequent analysis combining the estrogen arm with the estrogen + MPA arm and comparing with the placebo arm was also not significant in both the adjusted and the unadjusted models. Similar results were obtained when analyses were limited to women who took >80% of the study medication over the course of the trial (n = 133).

CONCLUSION

An average of 3.2 years of treatment with unopposed estrogen or estrogen plus progestins did not result in significant improvements in endothelial vasodilation compared with placebo. This apparent absence of an effect on brachial artery endothelial function in older postmenopausal women with established coronary heart disease may help explain the lack of benefit of estrogen for secondary prevention of coronary heart disease.

The ACE-DD genotype is associated with endothelial dysfunction in postmenopausal women

OBJECTIVE

To evaluate the effects of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D), the angiotensinogen M235T and the angiotensin II type 1 receptor A1166C polymorphisms, and hormone therapy used on endothelial function in postmenopausal women without manifestation of coronary artery disease.

DESIGN

Sixty-four postmenopausal women (42 hormone therapy users and 22 hormone therapy nonusers) without clinical manifestation of coronary artery disease were evaluated using external vascular ultrasonography to measure endothelium-dependent (hyperemic response, flow-mediated dilatation) and -independent (nitroglycerin) dilatation. Genotypes were determined by polymerase chain reaction amplification.

RESULTS

Women with the ACE-DD genotype displayed a lower flow-mediated dilatation compared to those with the ACE-II genotype (8.4% +/- 3.9% vs 12.6% +/- 5.4%, P = 0.04). Endothelial function was not associated with the angiotensinogen M235T and anglotensin II type 1 receptor A1166C polymorphisms. ACE polymorphism seems to modulate endothelial function among postmenopausal women without hormone therapy (8.2% +/- 5.1% vs 18.4% +/- 5.9% for the DD and the II genotype, respectively, P = 0.02). However, in hormone therapy users, flow-mediated dilatation was similar according to the ACE genotypes.

CONCLUSIONS

Our findings suggest that ACE-I/D polymorphism is related to endothelial dysfunction in postmenopausal women. Furthermore, a potential interaction between estrogen users and ACE polymorphism on endothelial function may be present.

Hormone Replacement Therapy and Cardioprotection: What Is Good and What Is Bad for the Cardiovascular System?

The incidence of cardiovascular diseases (CVDs) increases after menopause and at any age postmenopausal women have a significantly higher incidence of CVD compared to premenopausal women. Several epidemiological findings suggest the causative pathogenetic role of ovarian hormone deficiency in the development of CVD in women. Ovarian hormones have several potential protective effects on the cardiovascular system and despite several observational studies have shown the beneficial effect of estrogens and estrogen/progestin associations on CVD, at the present, after the findings of randomized studies, the effect of hormone replacement therapy (HRT) in the prevention of CVD is still under debate. The randomized studies (Heart and Estrogen/Progestin Replacement Study [HERS] and Women's Health Initiative [WHI]) found largely concordant results with the observational studies except for the divergent findings about coronary heart disease (CHD). The discrepancy between the two arms of the WHI study suggests that two factors, time to initiation of HRT since menopause and estrogen/progestin associations, are of pivotal importance to explain the widely divergent findings on the cardiovascular effects of observational studies and randomized clinical studies. Basic science and animal studies together with clinical investigations and the results of clinical studies are concordant in suggesting that a long time since menopause is associated with a reduced protective effect of estrogens while the unfavorable effects upon coagulation remain unaltered. In early postmenopausal women, like the ones included in the observational studies, ovarian hormone replacement may be cardioprotective because of the responsiveness of the endothelium to estrogens that also buffer the detrimental effects upon coagulation. In late postmenopausal women ovarian hormones have either a null effect or even a detrimental effect because of the predominance of the procoagulant or plaque-destabilizing effects over the vasoprotective effects. Therefore, HRT has beneficial cardiovascular effects in younger women while it may have detrimental effect on coagulative balance and vascular inflammation and has little effect on cardiovascular functions in older women.

The pathway-selective estrogen receptor ligand WAY-169916 displays differential activity in ischemia-reperfusion injury models

We previously reported on the development of a pathway-selective estrogen receptor (ER) ligand, WAY-169916, that has ER-dependent antiinflammatory activity and is devoid of classic ER transcriptional activity. In the current study, WAY-169916 and 17beta-estradiol (17beta-E2) were evaluated for protective activity in models of cardiac ischemia-reperfusion injury. In rats subjected to cardiac ischemia-reperfusion injury by occlusion of the left coronary artery, infarct size relative to the area at risk in the left ventricle was significantly attenuated by a single dose of 17beta-E2 (20 microg/kg, SC), and WAY-169916 administered SC (10 mg/kg) or IV (1 mg/kg) during the ischemia phase. In isolated hearts perfused on a Langendorff apparatus and subjected to global ischemia and reperfusion, 17beta-E2 and WAY-169916 both had direct cardioprotective activity when perfused at 1 microM but their effects varied between different end points. Perfusion with 17beta-E2 only improved recovery of left ventricle-developed pressure. Perfusion with WAY-169916 attenuated the elevation in perfusion pressure, diastolic pressure, and release of creatine kinase after ischemia. In contrast to 17alpha-ethinylestradiol, WAY-169916 had no classic estrogen effects on uterine weight or total serum cholesterol in rats treated for 4 days. The data demonstrate that the pathway-selective ER ligand WAY-169916 displays differential activity in vivo on different cardiovascular end points.

Novel aspects of endothelium-dependent regulation of vascular tone

The vascular endothelium plays a crucial role in the regulation of vascular homeostasis and in preventing the initiation and progress of cardiovascular disease by controlling mechanical functions of the underlying vascular smooth muscle. Three vasodilators: nitric oxide (NO), prostacyclin, and endothelium-derived hyperpolarizing factor, produced by the endothelium, underlie this activity. These substances act in a co-ordinated interactive manner to maintain normal endothelial function and operate as support mechanisms when one pathway malfunctions. In this review, we discuss recent advances in our understanding of how gender influences the interaction of these factors resulting in the vascular protective effects seen in pre-menopausal women. We also discuss how endothelial NO synthase (NOS) can act in both a pro- and anti-inflammatory action and therefore is likely to be pivotal in the initiation and time course of an inflammatory response, particularly with respect to inflammatory cardiovascular disorders. Finally, we review recent evidence demonstrating that it is not solely NOS-derived NO that mediates many of the beneficial effects of the endothelium, in particular, nitrite acts as a store of NO released during pathological episodes associated with NOS inactivity (ischemia/hypoxia). Each of these more recent findings has emphasized new pathways involved in endothelial biology, and following further research and understanding of the significance and mechanisms of these systems, it is likely that new and improved treatments for cardiovascular disease will result.

Serum vascular endothelial growth factor as a possible indicator of arterial reactivity in postmenopausal women

OBJECTIVE

To determine whether serum vascular endothelial growth factor (VEGF) concentration is correlated with arterial reactivity in postmenopausal women.

METHODS

An observational study was conducted on 24 postmenopausal women who did not receive any hormone therapy in the 6 months preceding the study and had no pre-existing cardiovascular diseases or cardiovascular risk factors. Serum samples were obtained from all participants and analyzed for VEGF concentrations. Arterial reactivity was assessed by the measurement of endothelium-dependent dilatation and endothelium-independent dilatation of the brachial artery, using color duplex Doppler ultrasound.

RESULTS

The study population was aged 50.8 years on average, with about 2 years of menopause. Serum VEGF concentration in postmenopausal women was significantly correlated with both endothelium-dependent dilatation (r = -0.66, p < 0.01) and endothelium-independent dilatation (r = -0.65, p < 0.01) of the brachial artery.

CONCLUSIONS

Serum VEGF level may be a potential indicator of arterial reactivity in postmenopausal women.

The association between endothelial dysfunction and cardiovascular outcomes in a population-based multi-ethnic cohort

BACKGROUND

Brachial artery flow-mediated dilation (FMD) may predict cardiovascular events in selected high-risk patients. Whether FMD testing predicts cardiovascular events in asymptomatic, lower risk individuals from the general population is unknown.

METHODS AND RESULTS

As a part of a multi-ethnic, prospective cohort study, the Northern Manhattan Study, we examined FMD by high-resolution ultrasonography in 842 community participants who were free of stroke or myocardial infarction. Lower FMD levels predicted cardiovascular events (myocardial infarction, stroke and vascular death) at 36 months of follow-up (hazard ratio (HR)=1.12 for every 1% decrease in FMD, 95% CI 1.01-1.25, p=0.03). The risk of events in patients with FMD in the lower two tertiles (FMD<7.5%) was significantly higher than those in the highest tertile (HR=3.28, 95% CI 1.07-10.06, p=0.04 for lowest versus highest tertile, and HR=3.05, 95% CI 1.03-9.66, p=0.04 for middle versus highest tertile). In a multivariate analysis including cardiovascular risk factors, the increase in risk associated with FMD was no longer statistically significant.

CONCLUSIONS

Non-invasive FMD testing predicts incident cardiovascular events in this multi-ethnic, population-based sample, but its predictive value is not independent of cardiovascular risk factors.

The effect of medroxyprogesterone acetate on estrogen-dependent risks and benefits--an attempt to interpret the Women's Health Initiative results

The results of the two arms of the Women's Health Initiative (WHI) study allow a comparative assessment of the contribution of the progestogen component to the changes in risk of cardiovascular disease and cancer during treatment of postmenopausal women with conjugated equine estrogens and medroxyprogesterone acetate (CEE/MPA). However, the high proportion of older and overweight or obese women compromises any conclusions, since we estimate that 50% of the women would have the metabolic syndrome. In overweight postmenopausal women with hyperinsulinemia, the risk of breast cancer is elevated and cannot be increased further by hormone replacement therapy (HRT). Therefore, the non-significant, but consistent reduction in breast cancer risk during treatment with CEE alone might be based on an improvement of hyperinsulinemia. The 24% increase in breast cancer risk in the CEE/MPA group can be regarded as an artifact due to very low numbers of breast cancer diagnoses in the placebo group of women who had received HRT prior to the WHI study. The elevated risk of venous thromboembolism and the transient increase in the risk of coronary heart disease (CHD) during treatment with CEE/MPA but not CEE alone suggests a direct effect of MPA on the vessel wall. MPA has been demonstrated to upregulate the thrombin receptor, the thrombin-induced production of tissue factor and procoagulatory activity in the vessel wall owing to its glucocorticoid activity. In contrast, CEE alone reduced non-significantly the risk of CHD in women aged 50-59 years, suggesting that primary prevention is possible if estrogen replacement therapy is initiated early. As clinical studies on the effect of different progestogens combined with estrogens are scarce, a possible superiority of progestogens other than MPA remains to be proven.

Endothelial function in post-menopausal former elite athletes

OBJECTIVE

To characterize endothelial function in postmenopausal former elite athletes in comparison to sedentary controls and to study the influence of hormone replacement therapy (HRT) on endothelial function in these groups of women.

DESIGN

Cross-sectional study.

SETTING

Research unit at a university hospital.

PARTICIPANTS

Twenty postmenopausal former elite but still active endurance female athletes and 19 age-matched sedentary controls. The group of athletes and control subjects were each subdivided into two groups on the basis of utilization or non-utilization of HRT involving estrogen and gestagen.

METHODS

Flow-mediated vasodilatation (FMD) was employed as an indicator of endothelial function. Fasting blood samples were analyzed for lipids and body composition determined by dual-energy x-ray absorptiometry.

MAIN OUTCOME MEASURES

FMD, blood lipids and body composition.

RESULTS

Former elite athletes not utilizing HRT demonstrated the highest FMD of all four subgroups, their values being significantly higher than those of control subjects not utilizing HRT (P < 0.05), whereas this difference was not seen between the subgroups of athletes and control subjects using HRT. Serum levels of cholesterol and low-density lipoprotein (LDL) and the percentage of fat mass were significantly lower in the former elite athletes than in the control group (P < 0.05 in all cases). However, these variables were not related to FMD.

CONCLUSION

This investigation documents enhanced endothelial function in postmenopausal former elite endurance athletes not utilizing HRT, whereas the use of HRT equalizes FMD in former athletes and sedentary control subjects. Our findings suggest that long-term strenuous exercise has beneficial effects on endothelial function in postmenopausal women but that no further improvement can be obtained with HRT.

Hormone replacement therapy and the cardiovascular system lessons learned and unanswered questions

Cardiovascular disease is the leading cause of death among women in the U.S., exceeding breast cancer mortality in women of all ages. Women present with cardiovascular disease a decade after men, and this has been attributed to the protective effect of female ovarian sex hormones that is lost after menopause. Animal and observational studies have shown beneficial effects of hormone therapy when it is initiated early in the perimenopausal period or before the development of significant atherosclerosis. However, randomized, placebo-controlled trials in older women have not shown any benefit in either primary prevention or secondary prevention of cardiovascular events, with a concerning trend toward harm. This review outlines the lessons learned from the basic science, animal, observational, and randomized trials, and then summarizes yet-unanswered questions of hormone therapy and cardiovascular risk.