Effects of transdermal 17beta-estradiol on left ventricular anatomy and performance in hypertensive women

Effects of Transdermal 17β-Estradiol + Norethisterone Acetate on Cardiovascular Disease Risk Factors in Postmenopausal Women: A Meta-analysis of Data From Randomized, Controlled Trials

PURPOSE

To date, no study has demonstrated the role of transdermal 17β-estradiol + norethisterone acetate on all of the risk factors for cardiovascular disease in postmenopausal women. To overcome this knowledge gap, a systematic review and meta-analysis were conducted to determine the effects of this combination treatment on BMI, body weight, waist/hip ratio, fibrinogen, factor VII, lipoprotein(a), fasting blood sugar, insulin, HbA1c, TG, LDL-C, HDL-C, and TC in postmenopausal women.

METHODS

PubMed/Medline, SCOPUS, Web of Science, Embase, and Google Scholar were searched for relevant articles published between the inception of each database and April 6, 2023. The sample size and mean (SD) were used to calculate overall effect size using a random-effects model.

FINDINGS

A total of 10 articles with 14 arms were included in the meta-analysis. On pooled analysis of effect size, fibrinogen (weighted mean difference [WMD], -0.18 g/L; 95% CI, -0.25 to -0.10), factor VII (WMD, -9.58; 95% CI, -12.51 to -6.64), LDL-C (WMD, -13.09 mg/dL; 95% CI, -18.48 to -7.71), and TC (WMD, -12.61 mg/dL; 95% CI, -18.11 to -7.12) were significantly affected with the use of transdermal 17β-estradiol + norethisterone acetate (all, P < 0.001), but effects on lipoprotein(a), TG, HDL-C, fasting blood sugar, insulin, HbA1c, BMI, body weight, and waist/hip ratio were not significant.

IMPLICATIONS

Based on the findings from the present systematic review and meta-analysis, it was concluded that transdermal administration of 17β-estradiol + norethisterone acetate had beneficial impacts on fibrinogen, factor VII, LDL-C, and TC, suggesting a possible application in the reduction of cardiovascular disease risk.

A prospective study on sex differences in functional capacity, quality of life and prognosis in patients with heart failure

BACKGROUND

Due to the lack of evidence and inconsistency of sex differences in Heart failure (HF) in the Chinese population, this study aimed to compare sex differences in functional capacity and quality of life (QoL) between women and men after standard HF medications therapies, and analyze whether sex differences were associated with the composite endpoints of all-cause mortality or HF-related hospitalization and cardiac event-free survival rate in Chinese patients with HF.

METHODS

This was a 1-year longitudinal study. Participants included patients with HF from March 2017 to December 2018. At baseline and followed up at 1, 6, and 12 months later, functional capacity was assessed by 6-minute walk testing (6MWT), QoL was measured with the Kansas City Cardiomyopathy Questionnaire (KCCQ) and EuroQoL five dimensions (EQ-5D). The Cox proportional hazards model and Kaplan-Meier curves were used to determine sex differences in subsequent outcomes. The Cox proportional hazards model was used to identify the risk factors for composite endpoints. Kaplan-Meier curves were used to compare survival.

RESULTS

All patients were assigned to either men group (n = 94) or women group (n = 60). Longitudinal follow-ups showed a continuously increasing in 6MWT, Kansas City Cardiomyopathy Questionnaire overall score, EQ-5D visual analogue scale, and EQ-5D Index score in both groups (all P < 0.001); however, women reported a lower level of all parameters at the 1, 6, and 12 months follow-ups (all P < 0.05). In addition, women had a higher risk of all-cause mortality or HF-related hospitalization and a lower cardiac event-free survival rate than men (log-rank test, P = 0.027).

CONCLUSION

Women reported worse functional capacity, QoL, and prognosis than men in a sample of Chinese patients with HF. Our findings highlight the importance of paying attention to sex differences in HF.

Effects of hormone replacement therapy on left ventricular diastolic function in postmenopausal women: a systematic review and meta-analysis

BACKGROUND

Postmenopausal women tend to experience significant changes in left ventricular diastolic function (LVDF). However, there are conflicting reports about LVDF between postmenopausal women on hormone replacement therapy (HRT) and those not on HRT. This meta-analysis is to evaluate the effects of HRT on LVDF in postmenopausal women.

METHODS

We conducted a systemic review of randomized controlled trials published up to December 31 2019 using Embase, Pubmed, and the Cochrane library database.

RESULTS

Eight studies involving 668 postmenopausal women were identified. Our analysis indicated that the ratio of the peak velocity during early filing to late filling from atrial contraction improvement in HRT group was better than that in placebo group (MD 0.20, 95%CI 0.12 to 0.28). There was a significant reduction in deceleration time and left ventricular mass index in HRT group compared with placebo group (MD -21.01, 95%CI -40.11 to -1.91 vs MD -8.26, 95%CI -14.10 to -2.42). No significant difference was observed in left ventricular end systole diameter (MD 0.80, 95%CI -0.72 to 2.31), left ventricular end diastole diameter (MD -0.07, 95%CI -1.25 to 1.10), left atrial size (MD -0.33, 95%CI -1.34 to 0.68)and the isovolumic relaxation time (MD -12.08, 95%CI -27.65 to 3.5).

CONCLUSIONS

Our meta-analysis illustrated that postmenopausal women seem to obtain more beneficial effects from HRT on LVDF, though future studies are required to elucidate the specific mechanisms for this phenomenon.

Sex related differences in the pathogenesis of organ fibrosis

The development of organ fibrosis has garnered rising attention as multiple diseases of increasing and/or high prevalence appear to progress to the chronic stage. Such is the case for heart, kidney, liver, and lung where diseases such as diabetes, idiopathic/autoimmune disorders, and nonalcoholic liver disease appear to notably drive the development of fibrosis. Noteworthy is that the severity of these pathologies is characteristically compounded by aging. For these reasons, research groups and drug companies have identified fibrosis as a therapeutic target for which currently, there are essentially no effective options. Although a limited body of published studies are available, most literature indicates that in multiple organs, premenopausal women are protected from developing severe forms of fibrosis suggesting an important role for sex hormones in mitigating this process. Investigators have implemented relevant animal models of organ disease linked to fibrosis supporting in general, these observations. In vitro studies and transgenic animals models have also been used in an attempt to understand the role that sex hormones and related receptors play in the development of fibrosis. However, in the setting of chronic disease in some organs such as the heart older (postmenopausal) women within a few years can quickly approach men in disease severity and develop significant degrees of fibrosis. This review summarizes the current body of relevant literature and highlights the imperative need for a major focus to be placed on understanding the manner in which sex and the presence or absence of related hormones modulates cell phenotypes so as to allow for fibrosis to develop.

ERβ targets ZAK and attenuates cellular hypertrophy via SUMO-1 modification in H9c2 cells

Aberrant expression of leucine zipper- and sterile ɑ motif-containing kinase (ZAK) observed in pathological human myocardial tissue is associated with the progression and elevation of hypertrophy. Our previous reports have correlated high levels of estrogen (E2) and abundant estrogen receptor (ER) α with a low incidence of pathological cardiac-hypertrophy and heart failure in the premenopause female population. However, the effect of elevated ERβ expression is not well known yet. Therefore, in this study, we have analyzed the cardioprotective effects and mechanisms of E2 and/or ERβ against ZAK overexpression-induced cellular hypertrophy. We have used transient transfection to overexpress ERβ into the ZAK tet-on H9c2 cells that harbor the doxycycline-inducible ZAK plasmid. The results show that ZAK overexpression in H9c2 cells resulted in hypertrophic effects, which was correlated with the upregulation of p-JNK and p-p38 MAPKs and their downstream transcription factors c-Jun and GATA-4. However, ERβ and E2 with ERβ overexpressions totally suppressed the effects of ZAK overexpression and inhibited the levels of p-JNK, p-p38, c-Jun, and GATA-4 effectively. Our results further reveal that ERβ directly binds with ZAK under normal conditions; however, ZAK overexpression reduced the association of ZAK-ERβ. Interestingly, increase in ERβ and E2 along with ERβ overexpression both enhanced the binding strengths of ERβ and ZAK and reduced the ZAK protein level. ERβ overexpression also suppressed the E3 ligase-casitas B-lineage lymphoma (CBL) and attenuated CBL-phosphoinositide 3-kinase (PI3K) protein association to prevent PI3K protein degradation. Moreover, ERβ and/or E2 blocked ZAK nuclear translocation via the inhibition of small ubiquitin-like modifier (SUMO)-1 modification. Taken together, our results further suggest that ERβ overexpression strongly suppresses ZAK-induced cellular hypertrophy and myocardial damage.

Short-term effects of low-dose estradiol on endothelial function and blood viscosity in nondiabetic postmenopausal overweight women: a double-blind, placebo-controlled study

OBJECTIVE

The beneficial effects of estrogen on endothelial function depend on its integrity. This study evaluates the short-term effects of low-dose transdermal estradiol on endothelial function, insulin sensitivity, and blood viscosity in nondiabetic overweight/obese women.

METHODS

Forty-four nondiabetic overweight/obese women with a history of recent menopause were randomly allocated, in a double-blind fashion, to receive transdermal estradiol (1 mg/d, n = 22) or placebo (n = 22). The following parameters were assessed: endothelial reactivity (venous occlusion plethysmography and nailfold videocapillaroscopy), plasma levels of soluble adhesion molecules, insulin sensitivity (homeostasis model assessment of insulin resistance and areas under the curve of insulin and glucose during an oral glucose tolerance test), and blood and plasma viscosity. Data were expressed as means ± SD or medians [first to third quartiles].

RESULTS

Participants were aged 51.8 ± 2.3 years with a body mass index of 31.5 ± 2.5 kg/m and time since menopause was 3 [2-5] years. At baseline, no differences between the groups were observed; however, after 3 months of treatment, the following changes were observed in the estradiol group compared with the placebo group: a decrease in the forearm vascular resistance at baseline (36.37 [24.9-51.27] vs 51.3 [40.88-70.03] mm Hg/mL per min 100 mL tissue, P < 0.01) and during the postocclusive reactive hyperemia response (15.93 [11.32-22.29] vs 22.13 [16.46-29.7] mm Hg/mL per min 100 mL tissue, P < 0.01), and an increase in red blood cell velocity at rest (0.316 [0.309-0.326] vs 0.303 [0.293-0.308] mm/s, P < 0.001) and during postocclusive reactive hyperemia response (0.374 [0.353-0.376] vs 0.341 [0.333-0.355] mm/s, P < 0.001). Furthermore, blood viscosity was lower in the estradiol group than in the placebo group (3.57 ± 0.12 vs 3.76 ± 0.22 mPa.s; P < 0.01).

CONCLUSIONS

Short-term use of low-dose transdermal estradiol in nondiabetic overweight/obese women with a history of recent menopause improved endothelial function and decreased blood viscosity compared with placebo.

Sex hormone levels and change in left ventricular structure among men and post-menopausal women: The Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVE

Sex hormone (SH) levels may contribute to sex differences in the risk of heart failure with preserved ejection fraction (HFpEF). We examined the associations of SH levels with left ventricular mass (LVM) and mass (M):volume (V) ratio, which are risk markers for HFpEF.

STUDY DESIGN

We studied 1941 post-menopausal women and 2221 men, aged 45-84 years, participating in the Multi-Ethnic Study of Atherosclerosis (MESA). Serum SH levels, cardiac magnetic resonance imaging (MRI) and ejection fraction (EF) ≥50% had been recorded at baseline (2000-2002). Of these participants, 2810 underwent repeat MRI at Exam 5 (2010-2012). Stratified by sex, linear mixed-effect models were used to test associations between SH and sex hormone binding globulin (SHBG) level [per 1 SD greater log-transformed (SH)] with baseline and change in LV structure. Models were adjusted for age, race/ethnicity, center, height, weight, education, physical activity and smoking, and, in women, for hormone therapy and years since menopause.

MAIN OUTCOME MEASURES

LVM and M:V ratio.

RESULTS

After a median of 9.1 years, higher free testosterone levels were independently associated with a modest increase in LVM (g/yr) in women [0.05 (95% CI 0.01, 0.10)] and men [0.16 (0.03, 0.28)], while higher SHBG levels were associated with less LVM change (g/yr) in women [-0.07 (-0.13, -0.01)] and men [-0.15 (-0.27, -0.02)]. In men, higher dehydroepiandrosterone and estradiol levels were associated with increased LVM. Among women, free testosterone levels were positively and SHBG levels inversely associated with change in M:V ratio.

CONCLUSION

A more androgenic profile (higher free testosterone and lower SHBG levels) is associated with a greater increase in LVM in men and women and greater increase in M:V ratio in women over the course of 9 years.

17-β estradiol attenuates ovariectomy-induced changes in cardiomyocyte contractile function via activation of AMP-activated protein kinase

Menopause increases the risk of cardiometabolic diseases in women. This circumstance is usually attributed to a deficiency in circulating estrogen levels although the underlying mechanism remains elusive. Given the pivotal role of AMP-activated protein kinase (AMPK) in the regulation of energy metabolism and cardiac function, this study was designed to examine the role of AMPK in estrogen deficiency and replacement-exerted cardiomyocyte responses. Adult female WT and AMPK kinase dead (KD) mice were subjected to bilateral ovariectomy (OVX) or sham operation. A cohort of ovariectomized mice received 17β-estradiol (E2) (40μg/kg/day, i.p.) for 6 weeks. Mechanical and intracellular Ca(2+) properties were evaluated including peak shortening (PS), time-to-PS (TPS), time-to-90%-relengthening (TR90), and maximal velocity of shortening/relengthening (±dL/dt). Levels of AMPK, Akt JNK, ACC, SERCA, membrane Glut4, AS160 and PGC-1α were assessed using Western blot. OVX significantly decreased PS, ±dL/dt and intracellular Ca(2+) rise in responsible to electric stimulus, prolonged TR90 and intracellular Ca(2+) decay without affecting TPS and resting intracellular Ca(2+), the effects of which were reconciled by E2 replacement. Western blot analysis depicted that OVX suppressed phosphorylation of Akt AMPK and ACC although it promoted JNK phosphorylation, the effects of which were mitigated or significantly attenuated by E2 treatment in WT but not KD mice. Moreover, OVX procedure downregulated SERCA2a and membrane Glut4 while inhibiting AS160 phosphorylation without affecting PGC-1α levels. In vitro study revealed that E2 corrected cardiomyocyte contractile dysfunction elicited by OVX in cardiomyocytes from WT but not the AMPK kinase dead mice. Taken together, these data suggest that E2 treatment ameliorates estrogen deficiency-induced changes in cardiac contractile function possibly through an AMPK-dependent mechanism.

Characterization of the cardiac renin angiotensin system in oophorectomized and estrogen-replete mRen2.Lewis rats

The cardioprotective effects of estrogen are well recognized, but the mechanisms remain poorly understood. Accumulating evidence suggests that the local cardiac renin-angiotensin system (RAS) is involved in the development and progression of cardiac hypertrophy, remodeling, and heart failure. Estrogen attenuates the effects of an activated circulating RAS; however, its role in regulating the cardiac RAS is unclear. Bilateral oophorectomy (OVX; n = 17) or sham-operation (Sham; n = 13) was performed in 4-week-old, female mRen2.Lewis rats. At 11 weeks of age, the rats were randomized and received either 17 β-estradiol (E2, 36 µg/pellet, 60-day release, n = 8) or vehicle (OVX-V, n = 9) for 4 weeks. The rats were sacrificed, and blood and hearts were used to determine protein and/or gene expression of circulating and tissue RAS components. E2 treatment minimized the rise in circulating angiotensin (Ang) II and aldosterone produced by loss of ovarian estrogens. Chronic E2 also attenuated OVX-associated increases in cardiac Ang II, Ang-(1–7) content, chymase gene expression, and mast cell number. Neither OVX nor OVX+E2 altered cardiac expression or activity of renin, angiotensinogen, angiotensin-converting enzyme (ACE), and Ang II type 1 receptor (AT1R). E2 treatment in OVX rats significantly decreased gene expression of MMP-9, ACE2, and Ang-(1–7) mas receptor, in comparison to sham-operated and OVX littermates. E2 treatment appears to inhibit upsurges in cardiac Ang II expression in the OVX-mRen2 rat, possibly by reducing chymase-dependent Ang II formation. Further studies are warranted to determine whether an E2-mediated reduction in cardiac chymase directly contributes to this response in OVX rats.

Hormonal regulation of β-myosin heavy chain expression in the mouse left ventricle

We investigated the influence of sex hormones on the expression of α- and β-cardiac myosin heavy chain isoforms (α-MHC and β-MHC) in C57bl/6 mice of both sexes under physiological and pathological conditions. In the left ventricles (LVs) of fertile female mice, β-MHC expression was tenfold higher compared with the age-matched males, whereas no difference was found in α-MHC expression. These differences disappeared after ovariectomy or in immature mice. We also found a sex-related difference in expression of β-adrenoceptors (β1-AR), as mRNA levels of this gene were 40% lower in fertile females compared with males of the same age but did not differ in prepubertal or ovariectomized animals. Interestingly, the deletion of both β1- and β2-ARs abolished sex difference of β-MHC expression, as mRNA levels in the LVs of knockout males were increased and reached values comparable to those of knockout females. Moreover, the β1-AR antagonist metoprolol induced about a threefold increase in β-MHC expression in adult male mice. The capability of gender to regulate β-MHC expression was also evaluated in the presence of hemodynamic overload. Thoracic aortic coarctation (TAC) produced cardiac hypertrophy along with a 12-fold increase in β-MHC and a 50% decrease in β1-AR expression in males but not in females, thus abolishing the gender difference observed in sham animals for such genes. By contrast, TAC did not change β2-AR expression. In conclusion, our results show that the expression of β-MHC and β1-AR in the LVs undergo gender-related and correlated changes under both physiological and pathological conditions and suggest a role of β1-AR-mediated signaling.

Activation of GPR30 attenuates diastolic dysfunction and left ventricle remodelling in oophorectomized mRen2.Lewis rats

AIMS

GPR30 is a novel oestrogen receptor expressed in various tissues, including the heart. We determined the role of GPR30 in the maintenance of left ventricular (LV) structure and diastolic function after the surgical loss of ovarian hormones in the female mRen2.Lewis rat, a model emulating the cardiac phenotype of the post-menopausal woman.

METHODS AND RESULTS

Bilateral oophorectomy (OVX) or sham surgery was performed in study rats; the selective GPR30 agonist, G-1 (50 µg/kg/day), or vehicle was given subcutaneously to OVX rats from 13-15 weeks of age. Similar to the cardiac phenotype of sham rats, G-1 preserved diastolic function and structure relative to vehicle-treated OVX littermates independent of changes in blood pressure. G-1 limited the OVX-induced increase in LV filling pressure, LV mass, wall thickness, interstitial collagen deposition, atrial natriuretic factor and brain natriuretic peptide mRNA levels, and cardiac NAD(P)H oxidase 4 (NOX4) expression. In vitro studies showed that G-1 inhibited angiotensin II-induced hypertrophy in H9c2 cardiomyocytes, evidenced by reductions in cell size, protein content per cell, and atrial natriuretic factor mRNA levels. The GPR30 antagonist, G15, inhibited the protective effects of both oestradiol and G-1 on this hypertrophy.

CONCLUSION

These data show that the GPR30 agonist G-1 mitigates the adverse effects of oestrogen loss on LV remodelling and the development of diastolic dysfunction in the study rats. This expands our knowledge of the sex-specific mechanisms underlying diastolic dysfunction and provides a potential therapeutic target for reducing the progression of this cardiovascular disease process in post-menopausal women.

Gender and the renin-angiotensin-aldosterone system

Premenopausal women are protected to some extent from cardiovascular and kidney diseases. Because this protection weakens after menopause, sex hormones are believed to play an important role in the pathogenesis of cardiovascular and kidney diseases. The cardiovascular system and the kidneys are regulated by the renin-angiotensin-aldosterone system (RAAS), which in turn, appears to be regulated by sex hormones. In general, oestrogen increases angiotensinogen levels and decreases renin levels, angiotensin-converting enzyme (ACE) activity, AT(1) receptor density, and aldosterone production. Oestrogen also activates counterparts of the RAAS such as natriuretic peptides, AT(2) receptor density, and angiotensinogen (1-7). Progesterone competes with aldosterone for mineralocorticoid receptor. Less is known about androgens, but testosterone seems to increase renin levels and ACE activity. These effects of sex hormones on the RAAS can explain at least some of the gender differences in cardiovascular and kidney diseases.

Influence of sex on treatment and outcome in chronic heart failure

The population is aging, the prevalence of heart failure increases with age, and on average women live longer than men. There is evidence for sex-specific effects of individual, guideline-recommended drugs used for treatment of chronic heart failure. Women are underrepresented in most clinical trials and only a minority of drug applications to regulatory authorities have included sex analyses. The present review focuses on the potential female survival benefit in heart failure, the influence of sex on medical treatment in a broader sense, and the potential benefit to be derived from guideline recommended treatment and common adjunctive heart failure medication.

Evaluation of left ventricular hypertrophy in hypertensive patients with echocardiographic myocardial videodensitometry normalized by displacement

Left ventricular hypertrophy (LVH) is an important predictor of cardiovascular morbidity and mortality. To investigate the feasibility of the myocardial grayscale intensity (GI) normalized by displacement (d) to discriminate between healthy and hypertrophic myocardium in hypertensive patients, sixty hypertensive patients and sixty age and sex-matched healthy volunteers were involved in this study. The peak d and the maximal GI [GI(max)] and minimal GI [GI(min)] for the middle interventricular septal (IVS) and the middle posterior wall (PW) at the level of papillary muscle were obtained from the standard parasternal long axis views using tissue tracking (TT) and videodensitometric analysis, respectively. The GI and the cyclic variation of GI (CVGI) normalized by d were calculated. The results showed that the d both for IVS and PW, the amplitude of CVGI for IVS in hypertensive patients with LVH were smaller than the ones without LVH and the normal subjects. But, the CVGI/d both for IVS and PW in hypertensive patients with LVH were all greater than the ones without LVH and the normal subjects. Moreover, the parameter, CVGI/d correlated positively with left ventricular mass index (LVMI). So, the method employed in this study, videodensitometric analysis in combination with TT allow objective and accurate determination of LVH and CVGI/d is a sensitive indicator for hypertensive patients with LVH.

Association of serum osteoprotegerin with left ventricular mass in African American adults with hypertension

BACKGROUND

African-Americans with hypertension are susceptible to left ventricular hypertrophy (LVH). Serum osteoprotegerin level has been reported to be associated with LVH. We investigated the association of osteoprotegerin with LV mass (LVM) in 898 African-Americans with hypertension (mean age 65 years, 71% women).

METHODS

Osteoprotegerin levels were measured in serum by an immunoassay and log-transformed for analyses. LVM index (LVMi; LVM/height(2.7)) was estimated using M-mode echocardiography. Linear regression analyses using generalized estimating equations were used to assess the association of osteoprotegerin with LVMi.

RESULTS

Serum osteoprotegerin was correlated with LVMi (r = 0.21; P < 0.0001), an estimated increase in LVMi of 5.05 (95% confidence interval 2.93, 7.17) g/m(2.7) in the highest compared to the lowest osteoprotegerin quartile. This association remained statistically significant after adjustment for conventional cardiovascular risk factors (age, sex, body mass index (BMI), history of smoking, diabetes, systolic blood pressure (BP), total and high-density lipoprotein cholesterol), estimated renal function, history of myocardial infarction and stroke, lifestyle factors (physical activity score, years of education, amount of alcohol consumption), medications (aspirin, antihypertensives, statins, estrogens), and C-reactive protein (CRP) (P = 0.02). Additionally, osteoprotegerin was correlated with early/atrial (E/A) ratio (r = -0.16; P < 0.0001), LV mean wall thickness (r = 0.17; P < 0.0001) and relative wall thickness (r = 0.14; P < 0.0001) but not ejection fraction (r = 0.04; P = 0.24) or internal end-diastolic dimension (r = 0.02; P = 0.60).

CONCLUSION

In African-Americans with hypertension, a higher serum osteoprotegerin level is weakly but independently associated with a higher LVM.

Sex and gender differences in myocardial hypertrophy and heart failure

Heart failure (HF) is a leading cause of cardiovascular mortality and morbidity in the Western world. It affects men at younger age than women. Women have more frequently diastolic HF, associated with the major risk factors of diabetes and hypertension and men have more frequently systolic HF because of coronary artery disease. Under stress, male hearts develop more easily pathological hypertrophy with dilatation and poor systolic function than female hearts. Women with aortic stenosis have more concentric hypertrophy with better systolic function, less upregulation of extracellular matrix genes and better reversibility after unloading. Stressed female hearts maintain energy metabolism better than male hearts and are better protected against calcium overload. Estrogens and androgens and their receptors are present in the myocardium and lead to coordinated regulation of functionally relevant pathways. Atrial fibrillation (AF) is a more ominous sign in women than in men. Men with end-stage cardiomyopathy more frequently have auto-antibodies than women. Women receive less guideline-based diagnostics and therapy. Expensive and invasive therapies such as advanced pacemakers and transplantation are underused in women. Drug studies point at sex differences in efficacy. Despite worse diagnostics and therapy, prognosis is better in women than in men.

Signaling responses after exposure to 5 alpha-dihydrotestosterone or 17 beta-estradiol in norepinephrine-induced hypertrophy of neonatal rat ventricular myocytes

Androgens appear to enhance, whereas estrogens mitigate, cardiac hypertrophy. However, signaling pathways in cells for short (3 min) and longer term (48 h) treatment with 17beta-estradiol (E2) or 5 alpha-dihydrotestosterone (DHT) are understudied. We compared the effect of adrenergic stimulation by norepinephrine (NE; 1 microM) alone or in combination with DHT (10 nM) or E2 (10 nM) treatment in neonatal rat ventricular myocytes (NRVMs) by cell area, protein synthesis, sarcomeric structure, gene expression, phosphorylation of extracellular signal-regulated (ERK), and focal adhesion kinases (FAK), and phospho-FAK nuclear localization. NE alone elicited the expected hypertrophy and strong sarcomeric organization, and DHT alone gave a similar but more modest response, whereas E2 did not alter cell size. Effects of NE dominated when used with either E2 or DHT with all combinations. Both sex hormones alone rapidly activated FAK but not ERK. Long-term or brief exposure to E2 attenuated NE-induced FAK phosphorylation, whereas DHT had no effect. Neither hormone altered NE-elicited ERK activation. Longer term exposure to E2 alone reduced FAK phosphorylation and reduced nuclear phospho-FAK, whereas its elevation was seen in the presence of NE with both sex hormones. The mitigating effects of E2 on the NE-elicited increase in cell size and the hypertrophic effect of DHT in NRVMs are in accordance with results observed in whole animal models. This is the first report of rapid, nongenomic sex hormone signaling via FAK activation and altered FAK trafficking to the nucleus in heart cells.

Sex-specific pathways in early cardiac response to pressure overload in mice

Pressure overload (PO) first causes cardiac hypertrophy and then heart failure (HF), which are associated with sex differences in cardiac morphology and function. We aimed to identify genes that may cause HF-related sex differences. We used a transverse aortic constriction (TAC) mouse model leading to hypertrophy without sex differences in cardiac function after 2 weeks, but with sex differences in hypertrophy 6 and 9 weeks after TAC. Cardiac gene expression was analyzed 2 weeks after surgery. Deregulated genes were classified into functional gene ontology (GO) categories and used for pathway analysis. Classical marker genes of hypertrophy were similarly upregulated in both sexes (α-actin, ANP, BNP, CTGF). Thirty-five genes controlling mitochondrial function (PGC-1, cytochrome oxidase, carnitine palmitoyl transferase, acyl-CoA dehydrogenase, pyruvate dehydrogenase kinase) had lower expression in males compared to females after TAC. Genes encoding ribosomal proteins and genes associated with extracellular matrix remodeling exhibited relative higher expression in males (collagen 3, matrix metalloproteinase 2, TIMP2, and TGFβ2, all about twofold) after TAC. We confirmed 87% of the gene expression by real-time polymerase chain reaction. By GO classification, female-specific genes were related to mitochondria and metabolism and males to matrix and biosynthesis. Promoter studies confirmed the upregulation of PGC-1 by E2. Less downregulation of metabolic genes in female hearts and increased protein synthesis capacity and deregulation of matrix remodeling in male hearts characterize the sex-specific early response to PO. These differences could contribute to subsequent sex differences in cardiac function and HF.

Ligand-dependent activation of ER{beta} lowers blood pressure and attenuates cardiac hypertrophy in ovariectomized spontaneously hypertensive rats

AIMS

The biological effects of oestrogens are mediated by two different oestrogen receptor (ER) subtypes, ERalpha and ERbeta, which might play different, redundant, or opposing roles in cardiovascular disease. Previously, we have shown that the selective ERalpha agonist 16alpha-LE2 improves vascular relaxation, attenuates cardiac hypertrophy, and increases cardiac output without lowering elevated blood pressure in spontaneously hypertensive rats (SHR). Because ERbeta-deficient mice exhibit elevated blood pressure and since the ERbeta agonist 8beta-VE2 attenuated hypertension in aldosterone-salt-treated rats, we have now tested the hypothesis that the isotype-selective ERbeta agonist 8beta-VE2 might be capable of lowering elevated blood pressure in ovariectomized SHR.

METHODS AND RESULTS

Treatment of ovariectomized SHR with 8beta-VE2 for 12 weeks conferred no uterotrophic effects but lowered elevated systolic blood pressure (-38 +/- 5 mmHg, n = 31, P < 0.001 vs. placebo) as well as peripheral vascular resistance (-31.3 +/- 4.6%, P < 0.001 vs. placebo). 8beta-VE2 enhanced aortic ERbeta expression (+75.7 +/- 7.1%, P < 0.01 vs. placebo), improved NO-dependent vasorelaxation, augmented phosphorylation of the vasodilator-stimulated phosphoprotein in isolated aortic rings (P < 0.05 vs. placebo), increased cardiac output (+20.4 +/- 2.5%, P < 0.01 vs. placebo), and attenuated cardiac hypertrophy (-22.2 +/- 3.2%, p < 0.01 vs. placebo). 8beta-VE2, in contrast to oestradiol, did not enhance cardiac alpha-myosin heavy chain expression.

CONCLUSION

Ligand-dependent activation of ERbeta confers blood pressure lowering effects in SHR that are superior to those of 17beta-estradiol or the ERalpha agonist 16alpha-LE2 and attenuates cardiac hypertrophy primarily by a reduction of cardiac afterload without promoting uterine growth.

Novel estrogen receptor alpha promoter polymorphism increases ventricular hypertrophic response to hypertension

Given the strong genetic contribution to blood pressure and left ventricular hypertrophy (LVH), and the influence of estrogen on these parameters, we hypothesized that polymorphisms in the estrogen receptor alpha (ERalpha) promoter may influence LVH. Three novel polymorphisms were identified upstream of the ERalpha alternatively spliced exon 1E, within sequence which demonstrated significant promoter activity in vitro. Demonstration of ERalpha E isoform expression in human ventricle by RT-PCR supported a possible functional role for the 1E novel polymorphisms in estrogen signaling in the heart. Indeed, G>A (-721 E) was significantly associated with LVH after controlling for systolic blood pressure and sex in a healthy population (n=74), contributing to 23% of interventricular septum (IVS) width variance (p<0.001) and 9.4% of left ventricular mass index (LVMI) variance (p=0.035). In a separate hypertensive cohort, male carriers of the A allele (n=8) had a 17% increase in IVS (95% CI: 6-28%) and a 19% increase in LVMI (3-34%) compared to GG homozygotes (n=84). We conclude that a novel polymorphism in the promoter of a cardiac mRNA splice isoform of ERalpha is associated with LVH.

Role of Gender in Heart Failure with Normal Left Ventricular Ejection Fraction

Heart failure with normal ejection fraction (HF-NEF) is frequently believed to be more common in women than in men. However, the interaction of gender and age has rarely been analyzed in detail, and knowledge of the distinction between pre- and postmenopausal women is lacking. Some of the studies that have described a higher prevalence of HF-NEF in women relied on clinical diagnoses of HF together with normal systolic function and did not measure diastolic function. This applies to the analysis of patients hospitalized for HF and some epidemiological investigations that agree on the greater prevalence of HF-NEF in women. Population-based studies with echocardiographic determination of diastolic function have suggested equal or greater prevalence of diastolic dysfunction in men. Major risk factors for HF-NEF include hypertension, aging, obesity, diabetes, and ischemia. Hypertension is more frequent in women and can contribute to left ventricular and arterial stiffening in a gender-specific way. Aging, obesity, and diabetes affect myocardial and vascular stiffness differently and lead to different forms of myocardial hypertrophy in women and men. In contrast, ischemia may play a greater role in men. Gender differences in ventricular diastolic distensibility, in vascular stiffness and ventricular/vascular coupling, in skeletal muscle adaptation to HF, and in the perception of symptoms may contribute to a greater rate of HF-NEF in women. The underlying molecular mechanisms include gender differences in calcium handling, in the NO system, and in natriuretic peptides. Estrogen affects collagen synthesis and degradation and inhibits the renin-angiotensin system. Effects of estrogen may provide benefit to premenopausal women, and the loss of its protective mechanisms may render the heart of postmenopausal women more vulnerable. Thus, a number of molecular mechanisms can contribute to the gender differences in HF-NEF.

Estrogen and hypertension

Menopause is accompanied by a dramatic rise in the prevalence of hypertension in women, suggesting a protective role of endogenous estradiol on blood pressure (BP). Both animal experimental and human clinical investigations suggest that estrogen engages several mechanisms that protect against hypertension, such as activation of the vasodilator pathway mediated by nitric oxide and prostacyclin and inhibition of the vasoconstrictor pathway mediated by the sympathetic nervous system and angiotensin. However, emerging evidence from recent clinical trials indicates a small increase, rather than decrease, in systolic BP with oral estrogen administration in postmenopausal women, without any detectable effect on diastolic BP. Mechanisms underlying this selective rise in systolic BP in postmenopausal women and oral contraceptive-induced hypertension in premenopausal women remain unknown, but the rise may be related to supraphysiologic concentration of estrogen in the liver. To date, transdermal delivery of estrogen, which avoids the first-pass hepatic metabolism of estradiol, appears to have a small BP-lowering effect in postmenopausal women and may be a safer alternative in hypertensive women.

Estrogen signaling in the cardiovascular system

Estrogen exerts complex biological effects through the two isoforms of estrogen receptors (ERs): ERα and ERβ. Whether through alteration of gene expression or rapid, plasma membrane-localized signaling to non-transcriptional actions, estrogen-activated ERs have significant implications in cardiovascular physiology. 17-β-estradiol (E2) generally has a protective property on the vasculature. Estrogen treatment is anti-atherogenic, protecting injured endothelial surfaces and lowering LDL oxidation in animal models. Increased NO production stimulated by E2 results in vasodilation of the coronary vascular bed, and involves rapid activation of phosphotidylinositol-3 kinase (PI3K)/Akt signaling to eNOS in carotid and femoral arteries. Both isoforms of ERs impact various vascular functions, modulating ion channel integrity, mitigating the response to arterial injury, inducing vasodilation, and preventing development of hypertension in animal models. In addition to reducing afterload by vasodilation, ERs have a direct antihypertrophic effect on the myocardium. E2-activated ERs (E2/ER) antagonize the hypertrophic pathway induced by vasoactive peptides such as angiotensin II by activating PI3K, subsequent MICIP gene expression, leading to the inhibition of calcineurin activity and the induction of hypertrophic genes. In models of ischemia-reperfusion, E2/ER is antiapoptotic for cardiomyocytes, exerting the protective actions via PI3K and p38 MAP kinases and suppressing the generation of reactive oxygen species. In sum, E2-activated ERs consistently and positively modulate multiple aspects of the cardiovascular system.

Isoflavones made simple - genistein's agonist activity for the beta-type estrogen receptor mediates their health benefits

Soy isoflavones, the focus of much research and controversy, are often referred to as "weak estrogens". In fact, genistein is a relatively potent agonist for the recently characterized beta isoform of the estrogen receptor (ERbeta). The low nanomolar serum concentrations of unconjugated free genistein achieved with high-nutritional intakes of soy isoflavones are near the binding affinity of genistein for this receptor, but are about an order of magnitude lower than genistein's affinity for the "classical" alpha isoform of the estrogen receptor (ERalpha). Moreover, these concentrations are far too low to inhibit tyrosine kinases or topoisomerase II, in vitro activities of genistein often cited as potential mediators of its physiological effects. The thesis that these physiological effects are in fact mediated by ERbeta activation provides a satisfying rationale for genistein's clinical activities. Hepatocytes do not express ERbeta; this explains why soy isoflavones, unlike oral estrogen, neither modify serum lipids nor provoke the prothrombotic effects associated with increased risk for thromboembolic disorders. The lack of uterotrophic activity of soy isoflavones reflects the fact that ERalpha is the exclusive mediator of estrogen's impact in this regard. Vascular endothelium expresses both ERalpha and ERbeta, each of which has the potential to induce and activate nitric oxide synthase; this may account for the favorable influence of soy isoflavones on endothelial function in postmenopausal women and ovariectomized rats. The ERbeta expressed in osteoblasts may mediate the reported beneficial impact of soy isoflavones on bone metabolism. Suggestive evidence that soy-rich diets decrease prostate cancer risk, accords well with the observation that ERbeta appears to play an antiproliferative role in healthy prostate. In the breast, ERalpha promotes epithelial proliferation, whereas ERbeta has a restraining influence in this regard - consistent with the emerging view that soy isoflavones do not increase breast cancer risk, and possibly may diminish it. Premenopausal women enjoy a relative protection from kidney failure; since ERbeta is an antagonist of TGF-beta signaling in mesangial cells, soy isoflavones may have nephroprotective potential. Estrogen also appears to protect women from left ventricular hypertrophy, and recent evidence suggests that this effect is mediated by ERbeta. In conjunction with reports that isoflavones may have a modestly beneficial impact on menopausal symptoms - perhaps reflecting the presence of ERbeta in the hypothalamus - these considerations suggest that soy isoflavone regimens of sufficient potency may represent a safe and moderately effective alternative to HRT in postmenopausal women. Further clinical research is required to characterize the impact of optimal genistein intakes on endothelial and bone function in men. Studies with ERbeta-knockout mice could be helpful for clarifying whether ERbeta does indeed mediate the chief physiological effects of low nanomolar genistein. S-equol, a bacterial metabolite of daidzein, has an affinity for ERbeta nearly as high as that of genistein; whether this compound contributes meaningfully to the physiological efficacy of soy isoflavones in some individuals is still unclear.

Cardiovascular alteration and treatment of hypertension: do men and women differ?

Cardiovascular disease is one of the most common causes of mortality affecting both men and women in industrialized nations. Sex-related differences have been well established with regard to heart and vascular function as well as cardiovascular disease processes. Nevertheless, the precise mechanisms of action behind these gender-related differences are poorly understood. Premenopausal women have a relatively lower arterial blood pressure compared to age-matched men and post-menopausal women, suggesting a role of ovarian hormones in blood pressure regulation. Sex-related differences in vasculature and neuroendocrine systems are also present that can affect hemostasis, vascular reactivity, and vascular tone. Treatment for cardiovascular disease and hypertension has been challenging and unsatisfactory. Men and women may require different antihypertensive regimens due to differences in the progression and presentation of hypertension. Additionally, hormone replacement therapy in postmenopausal women has been controversial, producing both beneficial and detrimental effects. Therefore, this review will focus on sex-related differences in the heart and vasculature, and treatments for cardiovascular disease, such as hypertension.

Effects of Hormone Replacement on Progression of Coronary Calcium as Measured by Electron Beam Tomography

PURPOSE

The recent Women's Health Initiative (WHI) results have demonstrated that combined estrogen plus progestin imparts a small but significant increase in cardiovascular risk and breast cancer among asymptomatic women. However, the effect and potential benefit of unopposed estrogen is not as clear. We sought to evaluate the progression of subclinical atherosclerosis in postmenopausal women using no hormone replacement therapy (HRT), combined therapy, and estrogen alone in an observational study.

METHODS

Postmenopausal women without symptoms or known coronary heart disease (CHD) were evaluated at our center for follow-up of coronary calcification. Patients were physician referred and underwent two consecutive electron beam tomography scans at least 1 year apart. All women fitting the study criteria were asked to participate, and those who consented were included. Demographic data, risk factors for CHD, HRT, and other medication use were collected by interview.

RESULTS

The study included 177 asymptomatic women. Calcium progression was 14.6%+/-21% in women taking any hormone therapy (n=97). Annual calcium progression rates in nonusers (n=80) was 22.3%+/-32%. Relative to the nonuser group, HRT treatment inhibited the progression of atherosclerosis by 35% (p=0.01). This effect was independent of age, risk, cardiovascular factors, statin use, or baseline CAC score. Thirty-five of the 97 women (36%) were taking estrogen plus progestin, with an annual increase in calcium scores of 24%+/-23%, similar to the non-HRT women (22%). Those women taking estrogen replacement only (n=62) was 63% lower (9%+/-22%).

CONCLUSIONS

This is an observational study, and the results are in accordance with the recently published WHI study, demonstrating no benefit of estrogen plus progestin compared with no therapy. However, women taking unopposed estrogen demonstrated a significant slowing of subclinical atherosclerosis compared with non-HRT and estrogen plus progestin.

Reduced ventricular flow propagation velocity in elite athletes is augmented with the resumption of exercise training

Chronic exercise induces physiological enlargement of the left ventricle ('athlete's heart'), but the effects of current and long-term exercise training on diastolic function have not been investigated. Echocardiography and Doppler imaging were used to assess left ventricular (LV) dimensions and indices of diastolic filling in 22 elite athletes at the end of their 'off-season' (baseline) and, subsequently, following 3 and 6 months of training. Twelve matched controls were also studied at baseline, 3 and 6 months. Compared to controls at baseline, athletes exhibited significantly higher LV mass (235.7 +/- 7.1 g versus 178.1 +/- 14.5 g, P < 0.01) and reduced flow propagation velocity (V(P): 50.21 +/- 1.7 versus 72.2 +/- 3.6 cm s(-1), P < 0.01), a measure of diastolic function. Three months of training further increased LV mass in athletes (253.2 +/- 7.1 g; P < 0.01 versus baseline), and significantly increased their V(P) (66.7 +/- 2.5 cm s(-1); P < 0.05 versus baseline). These trends for increased mass and diastolic filling persisted following 6 months of training (LV mass 249.0 +/- 8.7 g P < 0.05 versus baseline; V(P) 75.7 +/- 3.0 cm s(-1); P < 0.01 versus baseline, and P = 0.01 versus 3 months). This study suggests that following a period of relative inactivity the rate of ventricular relaxation during early diastole may be slowed in athletes who exhibit ventricular hypertrophy, whilst resumption of training increases the speed of ventricular relaxation in the presence of further hypertrophy of the left ventricle.

Effect of hormone therapy on BP in normotensive and hypertensive postmenopausal women

High blood pressure (BP) ranks as the greatest risk factor for cardiovascular disease. The increased cardiovascular risk determined in recent interventional studies has led the health authorities in some countries to re-ignite the discussion about whether hypertension should be listed as a contraindication for hormone replacement therapy (HRT). We reviewed papers published since 1960 and listed in MEDLINE, EMBASE and Biosis, on studies that monitored the course of BP during HRT. We found that both primarily normotensive and hypertensive postmenopausal women actually run only a very low risk of BP increase during HRT, indeed, BP was often lowered. In one of our own studies 1397 hypertensive women with BP diastolic >95 mmHg received transdermal HRT regimens; BP was lowered by an average of 7 mmHg systolic and 9 mmHg diastolic. The results of the more recent 24-h ambulatory BP studies are particularly conclusive. At least 19 such studies have been performed, 13 placebo-controlled and 10 cross-over; 5 found no effect on BP and 14 studies demonstrated BP reductions. BP was lowered by treatment with transdermal estradiol in 11 of 13 studies and by oral estrogen in 4 of 11 studies. The effects were not consistent with regard to systolic or diastolic BP nor to action on day- and night-time BP. It cannot be ruled out that some women with a particular predisposition exhibit an abnormal reaction to the vasoactive effects of HRT, and there is a paucity of long-term data on risk populations, specifically on the progestogenic effects in patients with pre-existing arteriosclerotic lesions. In conclusion, the risk of developing hypertension during HRT is very low, but hormone therapy should always be appropriately indicated and during therapy BP should be checked regularly.

The effect of valsartan on regression of left ventricular hypertrophy in type 2 diabetic patients

AIM

The aim of the present study was to examine the effects of an angiotensin II receptor antagonist, valsartan, on echocardiographically proven left ventricular hypertrophy (LVH) in patients with type 2 diabetes.

METHODS

Outpatients with type 2 diabetes mellitus were recruited at Niigata University Hospital. The left ventricular mass index (LVMI) was calculated by echocardiography. LVH was considered to be present if the LVMI was > 131 g/m(2) in males and > 100 g/m(2) in females. Patients with LVH received a low dose (40 mg/day) of valsartan for 12 months. This low dose had no clinical effect on blood pressure.

RESULTS

Of the 38 patients who entered the study, 14 (36.8%) had LVH. After only 6 months of valsartan therapy, the mean LVMI decreased significantly, from 126.5 +/- 27.8 to 119.0 +/- 23.5 g/m(2) (p < 0.01 vs. baseline). Also, a significant decrease was observed after 12 months (116.5 +/- 30.9 g/m(2), p < 0.05 vs. baseline). Compared to baseline, there were no significant differences after treatment in body mass index, glycosylated haemoglobin (HbA(1c)), systolic blood pressure and diastolic blood pressure.

CONCLUSIONS

In type 2 diabetic patients with LVH, treatment with a low dose of valsartan, an angiotensin II receptor antagonist, for 12 months, reduced LVMI, with no reduction in systemic blood pressure. This drug may be safely administered to type 2 diabetic patients with LVH. The long-term risk-reduction effects will have to be evaluated in further trials.

Effects of oral and transdermal low-dose estrogen therapy on echocardiographic parameters of cardiac function

OBJECTIVE

To investigate the effects of transdermal 17 beta-estradiol (E(2)) compared with oral unopposed as well as opposed E(2) on echocardiographic parameters of left ventricular (LV) systolic and diastolic function.

DESIGN

A prospective, randomized, double-blind, placebo-controlled, multi-center study.

SETTING

Gynecologic and cardiologic outpatient departments.

PATIENT(S)

One hundred fifty-two healthy hysterectomized postmenopausal women.

INTERVENTION(S)

Participants received daily placebo (n = 49) or transdermal E(2) (50 microg; tE(2) group, n = 33), or oral E(2) (1 mg; oE(2) group, n = 37), or oral E(2) (1 mg) combined with gestodene (25 microg; oE(2)+G group, n = 33) for thirteen 28-day treatment cycles.

MAIN OUTCOME MEASURE(S)

M-mode, quantitative two-dimensional, and Doppler echocardiographic measurements were performed at baseline and after 1 year.

RESULT(S)

Compared with placebo, tE(2) and oE(2) showed no statistically significant changes in LV function. oE(2)+G resulted in a statistically significant favorable increase in peak flow velocity, flow velocity integral, and mean acceleration. Furthermore, a favorable decrease was observed in interventricular septum thickness and ejection time.

CONCLUSION(S)

After 1 year of unopposed E(2), LV function remained unchanged. The oE(2)+G treatment showed a potential beneficial influence on LV systolic function.

Left ventricular mass index and ventricular septum thickness are associated with serum dehydroepiandrosterone-sulphate levels in hypertensive women

OBJECTIVE

Several data indicate that endogenous sex steroids might influence left ventricular mass. Our aim was to examine the association between dehyroepiandrosterone-sulphate (DHEAS) levels and left ventricular mass index (LVMI) and ventricular septal thickness (VST) in pre- and in postmenopausal women with treated essential hypertension.

PATIENTS AND METHODS

LVMI and VST were related to serum DHEAS in 26 pre- and in 34 postmenopausal women. The associations between DHEAS and LVMI, VST were adjusted for body mass index, duration of hypertension, systolic blood pressure, serum cholesterol and testosterone levels using a multiple regression model.

RESULTS

In premenopausal women there was a significant linear correlation between DHEAS and LVMI (P < 0.02) after adjustment for confounding variables. In contrast, DHEAS was inversely correlated with LVMI and VST in postmenopausal women (r = -0.49, P < 0.02, r =-0.42, P < 0.02, respectively). These associations also remained significant (P = 0.04, P = 0.03, respectively) after adjustment for confounding variables.

CONCLUSION

DHEAS might be an independent determinant of LVMI and VST. Its effect on the heart may depend on hormonal milieu. In premenopausal women, DHEAS might have androgenic effects and might enhance fibroblast proliferation; while during the postmenopausal period it is dominantly oestrogenic in action, with antiproliferative effect on cardiac cells.

17-beta-estradiol increases cardiac remodeling and mortality in mice with myocardial infarction

OBJECTIVES

This study was designed to examine the effects of estrogen replacement on infarct size, ventricular remodeling, and mortality after myocardial infarction (MI) in mice.

BACKGROUND

Observational and clinical studies suggest that the cardiovascular effects of hormone replacement therapy can differ depending on the patient population studied. No prospective studies have examined the effect of estrogen on outcomes following MI. We now examine the effects of estrogen replacement on infarct size, ventricular remodeling, and mortality after MI in mice.

METHODS

Myocardial infarction was induced by left coronary artery ligation in ovariectomized female mice treated with 17-beta-estradiol (E2) or placebo. At either one day or six weeks after MI, hemodynamic function was assessed, animals were euthanized, and infarct size was determined.

RESULTS

17-beta-estradiol-treated mice had smaller infarcts than placebo-treated animals both one day (18% decrease; p < 0.01), and six weeks (14% decrease; p < 0.05) following MI. E2 reduced cardiomyocyte apoptosis as assessed by the terminal deoxynucleotidyl transferase uridine nucleotide end-labeling method (50% reduction, p < 0.05) and caspase 3 activation (33% reduction, p < 0.05). Despite having smaller infarcts, however, left ventricular mass increased more in the E2-treated animals (16% greater; p < 0.01). Left ventricular weight was positively correlated with infarct size in the estrogen-treated animals (R2 = 0.79, p = 0.0001). 17-beta-estradiol treatment also significantly increased mortality in the infarcted animals (relative risk of death = 2.4; 95% confidence interval 1.2 to 5.3).

CONCLUSIONS

Estrogen replacement therapy reduces infarct size and cardiomyocyte apoptosis in mice. However, estrogen increased post-MI ventricular remodeling and mortality. Further studies will be necessary to elucidate the mechanisms underlying the complex effects of estrogen observed in the present study.

Oestrogen action on the myocardium in vivo: specific and permissive for angiotensin-converting enzyme inhibition

OBJECTIVES

In contrast to the vasculature, it remains unclear whether oestrogens also directly affect the myocardium. In this study, we addressed basic questions regarding oestrogen effects on the myocardium, including specificity, pathophysiological relevance and potential clinical implications, with a special focus on interactions between oestrogen and angiotensin-converting enzyme (ACE) inhibitors in an established in-vivo model of cardiac hypertrophy.

METHODS AND RESULTS

Female spontaneously hypertensive rats (SHR) were ovarectomized (OVX) or sham-operated and treated with 17beta-oestradiol (2 microg/kg per day subcutaneously), the oestrogen receptor antagonist ZM-182780 (250 microg/kg per day subcutaneously) and the ACE-inhibitor moexipril (10 mg/kg per day orally) alone or in combination for 3 months. Hormone replacement restored physiological oestradiol serum levels and prevented uterus atrophy. Whereas moexipril alone was ineffective in OVX rats, substitution of oestradiol restored the beneficial effect of moexipril on systolic blood pressure (-30 +/- 5 mmHg) and relative heart weight (-11 +/- 3%) in OVX rats. Oestradiol upregulated alpha-myosin heavy chain (MHC) mRNA (+37 +/- 7%) and protein expression (+43 +/- 6%) in spite of increased blood pressure in OVX rats. Simultaneous treatment with oestradiol plus moexipril most effectively shifted the ratio of alpha-/beta-MHC mRNA and protein expression towards alpha-MHC in OVX animals. Oestradiol (10 nmol/l) also upregulated alpha-MHC mRNA and protein in cultured cardiac myocytes. The oestrogen receptor antagonist ZM-182780 significantly inhibited the observed oestrogen effects.

CONCLUSIONS

Oestrogen replacement is permissive for the beneficial effects of ACE-inhibition in female SHR rats. Oestrogen effects on the myocardium in vivo are specific (i.e. oestrogen receptor mediated) because they are inhibited by a pure oestrogen receptor antagonist and occur at physiological hormone levels.

Effects of hormone replacement therapy on left ventricular hypertrophy and growth-promoting factors in hypertensive postmenopausal women

We investigated the effects of hormone replacement therapy (HRT) on left ventricular hypertrophy (LVH) and growth-promoting factors in hypertensive postmenopausal women (PMW) with LVH. Twenty-one Japanese hypertensive PMW (age 55.3+/-0.8 years) with LVH who had never received HRT volunteered to participate in this study. Eleven subjects received a daily dose of HRT (0.625 mg conjugated equine estrogen, 2.5 mg medroxyprogesterone acetate) orally for 12 months. Ten PMW who refused HRT were enrolled as controls. Blood pressure and serum angiotensin-converting enzyme (ACE) activity, plasma aldosterone, and insulin resistance were measured. M-mode echocardiography and blood pressure measurements were performed in all patients. Data obtained before and after 12 months of HRT were compared. No significant differences in blood pressure were observed between the two groups after 12 months of HRT. In the HRT group, the LV mass index (p<0.01), serum ACE activity (p<0.01), and plasma aldosterone (p<0.01) levels were reduced after 12 months of treatment. The changes in serum ACE activity and plasma aldosterone were not correlated with the change in LV mass index in the HRT group. No significant changes in blood pressure, LV mass index, serum ACE activity, plasma aldosterone, or insulin resistance were observed in the control group. HRT contributed to the reduction of LV mass in hypertensive PMW. However, the effect of HRT on LVH did not appear to be associated with changes in growth-promoting factors, such as blood pressure, serum ACE activity, plasma aldosterone, and insulin resistance.

Influence of 17beta-oestradiol on blood pressure of postmenopausal women at high vascular risk

OBJECTIVES

It remains an unsolved issue whether hormone replacement therapy (HRT) lowers blood pressure. This randomized trial examined the effect of 17beta-oestradiol combined cyclically with gestodene on blood pressure of postmenopausal women who were not on antihypertensive medication. All subjects had an increased risk for adverse vascular events as indicated by intima-media thickness of carotid arteries and standard risk factors.

DESIGN AND SETTING

Two hundred and twenty-six postmenopausal women were randomized to oral treatment for 48 weeks with 1 mg of 17beta-oestradiol per day continuously, plus 0.025 mg gestodene on days 17-28 of each 4-week cycle (HRT 1), or plus gestodene in each third cycle only (HRT 2), or no HRT. According to predefined criteria, four subjects in HRT 1, 12 in HRT 2 and 13 in no HRT who were started on antihypertensive medication were excluded from the analysis. Thirty subjects ended participation prematurely for other reasons. Resting blood pressure was measured at baseline and after 12, 22 and 48 weeks.

RESULTS

During treatment diastolic blood pressure changed significantly in both HRT groups compared to no HRT, by -3.7 +/- 9.8 mmHg, -3.0 +/- 8.8 mmHg and 1.0 +/- 9.9 mmHg at week 48 in groups HRT 2, HRT 1 and no HRT, respectively (P = 0.008 for HRT 2 versus no HRT, P = 0.027 for HRT 1 versus no HRT). The higher the diastolic blood pressure was at beginning the greater was the decrease. The decrease of systolic blood pressure was not significantly different between groups.

CONCLUSIONS

For postmenopausal women with high cardiovascular risk but without antihypertensive medication, long-term treatment with 17beta-oestradiol combined with gestodene lowers diastolic blood pressure.

Effect of sex hormones on cardiac mass

Increased left-ventricular mass is an important cardiovascular risk factor for morbidity and mortality. Apart from obvious differences in cardiac size, the changes in left-ventricular mass in response to age and hypertrophic stimuli are very different in men and women. Whereas left-ventricular mass increases with age in apparently healthy women, it remains constant in men. Under increased cardiac loading conditions, such as hypertension or aortic stenosis, this disparity between sexes is even more striking. Findings are especially pronounced in people aged 50 years or older, in whom reproductive hormone concentrations have fallen. Whether the differences in left-ventricular mass changes are related to endogenous sex-hormone concentrations has never been shown. Androgens have anabolic effects on cardiac cells, and oestrogens have antiproliferative properties, we therefore postulate that the normal decline in endogenous sex hormones with age has contrary effects on ventricular mass in men and women in normal and pathological states.

Transdermal estrogen reduces vascular resistance and serum cholesterol in postmenopausal women

OBJECTIVE

Our aim was to compare the effects of transdermal versus oral estrogens on vascular resistance index, mean arterial pressure, serum lipid concentrations, norepinephrine, and left ventricular structure.

STUDY DESIGN

Ten postmenopausal women received transdermal estradiol (0.05 mg/d) plus cyclic oral progesterone for 6 months. Responses were compared with those of 23 women receiving oral conjugated estrogens (0.625 mg/d) plus cyclic progesterone and with those of 9 subjects receiving placebo in a concurrent randomized trial. We assessed the vascular resistance index and the mean arterial pressure at rest and during behavioral stressors.

RESULTS

Oral and transdermal estrogen significantly decreased the vascular resistance index, mean arterial pressure, norepinephrine, and total and low-density lipoprotein cholesterol to a similar extent. Changes in the vascular resistance index and mean arterial pressure were equally evident at rest and during stress. Although both treatments reduced left ventricular mass (-4% to -6%) and relative wall thickness (-3% to -5%), these changes were not statistically significant.

CONCLUSIONS

Equivalent reductions in vascular resistance index, norepinephrine, mean arterial pressure, and cholesterol were observed with transdermal and oral estrogens. Future studies comparing novel hormone regimens with oral hormone replacement therapy should include multiple risk markers to allow better assessment of their potential impact on coronary artery health.

The heart as a target for oestrogens

Observational studies have consistently shown a markedly decreased risk of cardiovascular disease in postmenopausal women when treated with oestrogens. This review discusses plausible mechanisms for the physiological effects of oestrogens in healthy and diseased hearts. Oestrogens have well-documented effects on blood lipids and the regulators of the cardiovascular system, which should reduce risk. In addition, the heart is a primary target for oestrogens with functional oestrogen receptors in the coronary vasculature and on cardiac myocytes and fibroblasts. Rapid oestrogen effects include vasodilatation and anti-arrhythmic effects by actions on ion channels, and some of these effects may be pharmacological rather than physiological. Longer term responses to physiological levels of oestrogen include an increased expression of nitric oxide synthase in myocytes and endothelial cells as well as proinflammatory and pro-arrhythmic effects. Oestrogens induce growth of non-proliferating fibroblasts but inhibit the replication of proliferating fibroblasts. In contrast to the observational studies, two randomised, controlled studies of oestrogen and progestins in postmenopausal women with coronary heart disease have now shown increased coronary events, especially in the first year of study, and no change in the progression of coronary atherosclerosis. Further studies of the complex effects of oestrogens on healthy and diseased animal models are essential. Large clinical trials of the newer selective oestrogen receptor modulators to lower cardiovascular risk in both males and females should be considered as a priority.