Acute and chronic effects of oestradiol on left ventricular diastolic function in hypertensive postmenopausal women with left ventricular diastolic dysfunction

Impact of estradiol, testosterone and their ratio on left and right auricular myofilament function in male and female patients undergoing coronary artery bypass grafting

BACKGROUND

The impact of sex hormones on right and left auricular contractile apparatus function is largely unknown. We evaluated the impact of sex hormones on left and right heart contractility at the level of myocardial filaments harvested from left and right auricles during elective coronary artery bypass surgery.

METHODS

150 patients (132 male; 18 female) were enrolled. Preoperative testosterone and estradiol levels were measured with Immunoassay. Calcium induced force measurements were performed with left- and right auricular myofilaments in a skinned fiber model. Correlation analysis was used for comparison of force values and levels of sex hormones and their ratio.

RESULTS

Low testosterone was associated with higher top force values in right-sided myofilaments but not in left-sided myofilaments for both sexes (p = 0.000 in males, p = 0.001 in females). Low estradiol levels were associated with higher top force values in right-sided myofilaments (p 0.000) in females and only borderline significantly associated with higher top force values in males (p 0.056). In females, low estradiol levels correlated with higher top force values in left sided myofilaments (p 0.000). In males, higher Estradiol/Testosterone ratio (E/T ratio) was only associated with higher top force values from right auricular myofilaments (p 0.04) In contrast, in females higher E/T ratio was associated with lower right auricular myofilament top force values (p 0.03) and higher top force values in left-sided myofilaments (p 0.000).

CONCLUSIONS

This study shows that patients' comorbidities influence left and right sided contractility and may blur results concerning influence of sex hormones if not eliminated. A sex hormone dependent influence is obvious with different effects on the left and right ventricle. The E/T ratio and its impact on myofilament top force showed divergent results between genders, and may partially explain gender differences in patients with cardiovascular disease.

Serum testosterone level correlates with left ventricular hypertrophy in older women

Introduction

Sex hormones may play an important role in age-related cardiac remodeling. However, their impact on cardiac structure and function in females of advanced age still remains unclear. The aim of this study is to evaluate the relationship between sex hormones level and echocardiographic parameters in older women with concomitant cardiovascular diseases.

Materials and Methods

The study group included 52 community-dwelling women with mean age 79.5 ± 2.8 years, consecutive patients of an outpatient geriatric clinic. In all the subjects, a transthoracic echocardiogram was performed and serum testosterone, estradiol, follicle-stimulating hormone, luteinising hormone, dehydroepiandrosterone sulphate, and cortisol levels were determined.

Results

Testosterone level correlated positively with interventricular septum diastolic dimension (IVSd) (rS=0.293, p<0.05), left ventricular mass index (rS=0.285, p<0.05), E/E' ratio (rS=0.301, p<0.05), and negatively with E' (rS=-0.301, p<0.05). Estradiol level showed a positive correlation with the posterior wall dimension (rS=0.28, p<0.05). Besides, no significant correlations between clinical or echocardiographic parameters and other hormones were observed. Female subjects with diagnosed left ventricular hypertrophy (LVH) (n=34) were characterized by a significantly higher rate of hypertension (p=0.011), higher waist-to-height ratio (p=0.009), higher testosterone level (0.82 vs. 0.48 nmol/L, p=0.024), higher testosterone/estradiol ratio (16.4 vs. 9.9, p=0.021), and received more anti-hypertensive drugs (p=0.030). In a multiple stepwise logistic regression, the best determinants of LVH were the presence of hypertension (OR=6.51; 95% CI 1.62-26.1), and testosterone level (OR= 6.6; 95% CI 1.19-36.6).

Conclusions

Higher serum testosterone levels may contribute to pathological cardiac remodeling, especially in hypertensive women. Estradiol, gonadotropins, DHEAS, and cortisol were not related to echocardiographic parameters.

Heart failure with preserved ejection fraction: Squaring the circle between comorbidities and cardiovascular abnormalities

Heart Failure with preserved Ejection Fraction (HFpEF) is nowadays considered a major healthcare issue. According to forecasts two third of all Heart Failure patients will belong to this phenotype by year 2050, overwhelming those affected by Heart Failure with reduced Ejection Fraction (HFrEF). Both epidemiological and mechanistic studies support the concept that HFpEF represents true HF although aggravated by a collection of comorbidities. There is urgent need of improving its phenotyping due to the high degree of disease heterogeneity within HFpEF that lead to the failure of randomized clinical trials in demonstrating a remarkable impact of drugs in improving its morbidity and mortality.

Myocardial Tissue Characterization in Heart Failure with Preserved Ejection Fraction: From Histopathology and Cardiac Magnetic Resonance Findings to Therapeutic Targets

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome responsible for high mortality and morbidity rates. It has an ever growing social and economic impact and a deeper knowledge of molecular and pathophysiological basis is essential for the ideal management of HFpEF patients. The association between HFpEF and traditional cardiovascular risk factors is known. However, myocardial alterations, as well as pathophysiological mechanisms involved are not completely defined. Under the definition of HFpEF there is a wide spectrum of different myocardial structural alterations. Myocardial hypertrophy and fibrosis, coronary microvascular dysfunction, oxidative stress and inflammation are only some of the main pathological detectable processes. Furthermore, there is a lack of effective pharmacological targets to improve HFpEF patients' outcomes and risk factors control is the primary and unique approach to treat those patients. Myocardial tissue characterization, through invasive and non-invasive techniques, such as endomyocardial biopsy and cardiac magnetic resonance respectively, may represent the starting point to understand the genetic, molecular and pathophysiological mechanisms underlying this complex syndrome. The correlation between histopathological findings and imaging aspects may be the future challenge for the earlier and large-scale HFpEF diagnosis, in order to plan a specific and effective treatment able to modify the disease's natural course.

Associations between menopause, cardiac remodeling, and diastolic function: the CARDIA study

OBJECTIVES

Heart failure with preserved ejection fraction (HFpEF) affects more women than men. Menopause may influence HFpEF development in women. We assessed cross-sectional and longitudinal associations between menopause and echocardiographic measures of left ventricular (LV) function and cardiac remodeling.

METHODS

We studied 1,723 women with available echo data from at least two of: year 5 (Y5) (1990-1991), Y25 (2010-2011), or Y30 (2015-2016) in the Coronary Artery Risk Development in Young Adults study. Cardiac structure and function were measured using 2D and Doppler echocardiography. Cross-sectional associations between menopausal status and repeated echo measures at Y25 and Y30 were analyzed using linear mixed models. Two-segmented models were used to compare longitudinal changes in echocardiographic measures in the premenopausal period to changes in the postmenopausal period.

RESULTS

Mean ± SD age (years) at enrollment was 27 ± 3 in those with menopause by Y25, 25 ± 3 in those with menopause between Y25 and Y30, and 21 ± 3 in those premenopausal at Y30. There were no significant differences in race, body mass index, systolic blood pressure, or diabetes between the groups. Postmenopausal women had higher early diastolic mitral inflow (E) to annular (e') velocity ratio than premenopausal after adjusting for demographics and risk factors (P < 0.05). Menopause was associated with relative increases in the rates of change in LV mass and left atrial volume, even after adjustment. Change in E/e' ratio was similar before and after menopause.

CONCLUSIONS

Menopause is associated cross-sectionally with worse diastolic function and longitudinally with adverse LV and left atrial remodeling. This may contribute to the increased HFpEF risk in postmenopausal women.

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.

Cellular and Molecular Differences between HFpEF and HFrEF: A Step Ahead in an Improved Pathological Understanding

Heart failure (HF) is the most rapidly growing cardiovascular health burden worldwide. HF can be classified into three groups based on the percentage of the ejection fraction (EF): heart failure with reduced EF (HFrEF), heart failure with mid-range-also called mildly reduced EF- (HFmrEF), and heart failure with preserved ejection fraction (HFpEF). HFmrEF can progress into either HFrEF or HFpEF, but its phenotype is dominated by coronary artery disease, as in HFrEF. HFrEF and HFpEF present with differences in both the development and progression of the disease secondary to changes at the cellular and molecular level. While recent medical advances have resulted in efficient and specific treatments for HFrEF, these treatments lack efficacy for HFpEF management. These differential response rates, coupled to increasing rates of HF, highlight the significant need to understand the unique pathogenesis of HFrEF and HFpEF. In this review, we summarize the differences in pathological development of HFrEF and HFpEF, focussing on disease-specific aspects of inflammation and endothelial function, cardiomyocyte hypertrophy and death, alterations in the giant spring titin, and fibrosis. We highlight the areas of difference between the two diseases with the aim of guiding research efforts for novel therapeutics in HFrEF and HFpEF.

The Role of Estrogen in Cardiac Metabolism and Diastolic Function

Heart failure with preserved ejection fraction (HFpEF) has similar prevalence and prognosis as HF with reduced EF, but there is no approved treatment for HFpEF. HFpEF is common in postmenopausal women, which suggests that the absence of estrogen (E2) plays a role in its pathophysiology. With the country's growing elderly population, the prevalence of HFpEF is rapidly increasing. This has triggered a renewed urgency in finding novel approaches to preventing and slowing the progression of HFpEF. In this review, we address the role of E2 in left ventricular diastolic function and how it impacts women with HFpEF as well as animal models. We also discuss the primary potential mechanisms that represent critical nodes in the mechanistic pathways of HFpEF and how new treatments could be developed to target those mechanisms.

Chronic treatment with angiotensin-converting enzyme inhibitor increases cardiac fibrosis in young rats submitted to early ovarian failure

BACKGROUND

We investigated whether the treatment with enalapril maleate, combined with aerobic physical training, promotes positive effects on the autonomic balance, the morphology and the cardiac function in female rats submitted to early ovarian failure.

METHODS

Thirty-five female Wistar rats, ovariectomized at 10weeks of age, were assigned into Ovariectomized rats (OVX) and Ovariectomized rats treated with enalapril maleate (OVX-EM, 10mg^-1·kg^-1·d^-1) Each group was subdivided into sedentary and trained (aerobic swimming training for 10weeks). All animals were submitted to a) double pharmacological autonomic blockade, b) study of morphology and cardiac function by echocardiography, and c) analysis of cardiac fibrosis.

RESULTS

The OVX-EM sedentary group showed a significant increase in cardiac fibrosis, relative heart weight, interventricular septum thickness and increased sympathetic participation and reduced participation of the vagal tone in the determination of the basal heart rate when compared to the OVX sedentary group. Physical training reduced cardiac fibrosis in both groups, however, with less intensity in the OVX-EM group. It also increased the absolute and relative heart weight and the end-systolic volume. Finally, the OVX-EM trained group showed higher values for left ventricular end-systolic volume and lower values for ejection fraction and shortening fraction than the sedentary OVX-EM group.

CONCLUSION

Enalapril maleate exacerbated cardiac fibrosis and increased sympathetic participation in the basal heart rate determination, without significantly affecting the cardiac function. Aerobic physical training did not change the cardiac autonomic control, but reduced cardiac fibrosis and had little effect on the cardiac function.

Regular exercise modulates cardiac mast cell activation in ovariectomized rats

It is well accepted that regular exercise is a significant factor in the prevention of cardiac dysfunction; however, the cardioprotective mechanism is as yet not well defined. We have examined whether regular exercise can modulate the activity of cardiac mast cells (CMC) after deprivation of female sex hormones, as well as the density and percentage degranulation of mast cells, in ventricular tissue of ovariectomized (OVX) rats after an 11-week running program. A significant increase in CMC density with a greater percentage degranulation was induced after ovarian sex hormone deprivation. Increased CMC density was prevented by estrogen supplements, but not by regular training. To the contrary, increased CMC degranulation in the OVX rat heart was attenuated by exercise training, but not by estrogen supplement. These findings indicate a significant correlation between the degree of CMC degranulation and myocyte cross-section area. However, no change in the expression of inflammatory mediators, including chymase, interleukin-6, and interleukin-10, was detected. Taken together, these results clearly indicate one of the cardioprotective mechanisms of regular aerobic exercise is the modulation of CMC activation.

Serum uric acid is associated with cardiac diastolic dysfunction among women with preserved ejection fraction

Serum uric acid (SUA) is associated with the severity and prognosis of systolic heart failure. We investigated the potential association between SUA and cardiac diastolic dysfunction among total of 744 cardiac patients (202 women and 542 men) who had preserved left ventricular ejection fraction. Presence of diastolic dysfunction was assessed by echocardiographic data, plasma B-type natriuretic peptide concentration, and left ventricular hypertrophy. Univariate analysis showed that the prevalence of diastolic dysfunction increased with increasing SUA value in women, but not in men. When sex-nonspecific SUA quartiles were used, multivariate logistic regression analysis, among female patients who were not taking uric acid lowering medication, showed that the third (SUA, 5.7-6.4 mg) and the fourth (SUA, ≥6.5 mg/dl) SUA quartiles were associated with diastolic dysfunction with an odds ratio of 3.25 (P < 0.05) and 8.06 (P < 0.001), respectively, when compared with the first SUA quartile (≤4.7 mg/dl). When sex-specific SUA quartiles were used among these population, multivariate logistic regression analysis showed that the fourth SUA quartile (≥5.7 mg/dl) was associated with diastolic dysfunction with an odds ratio of 5.34 (P < 0.05) when compared with the first SUA quartile (≤4.1 mg/dl). By contrast, the relationship between SUA and diastolic dysfunction was not significant in men, irrespective of which of the sex-nonspecific or sex-specific SUA quartiles were used. These data indicated that among cardiac patients with preserved ejection fraction, SUA was significantly associated with diastolic dysfunction in women but not in men.

Sex hormones in the cardiovascular system

Gender-associated differences in the development of cardiovascular diseases have been described in humans and animals. These differences could explain the low incidence of cardiovascular disease in women in the reproductive period, such as stroke, hypertension, and atherosclerosis. The cardiovascular protection observed in females has been attributed to the beneficial effects of estrogen on endothelial function. Besides estrogen, sex hormones are able to modulate blood pressure by acting on important systems as cardiovascular, renal, and neural. They can have complementary or antagonistic actions. For example, testosterone can raise blood pressure by stimulating the renin-angiotensin-aldosterone system, whereas estrogen alone or combined with progesterone has been associated with decreased blood pressure. The effects of testosterone in the development of cardiovascular disease are contradictory. Although some researchers suggest a positive effect, others indicate negative actions of testosterone. Estrogens physiologically stimulate the release of endothelium-derived vasodilator factors and inhibit the renin-angiotensin system. Although the cardioprotective effects of estrogen are widely appreciated, little is known about the effects of progesterone, which is commonly used in hormone replacement therapy. Progesterone has both vasodilatory and vasoconstrictive effects in the vasculature, depending on the location of the vessel and the level of exposure. Nevertheless, the mechanisms through which sex hormones modulate blood pressure have not been fully elucidated. Therefore, the characterization of those could lead to a better understanding of hypertension in women and men and perhaps to improved forms of therapy.

Aerobic physical training increases contractile response and reduces cardiac fibrosis in rats subjected to early ovarian hormone deprivation

We investigated the effects of early ovarian hormone deprivation on the heart and the role of physical training in this condition using different approaches: cardiac autonomic tone, contractility, morphology and function, and cardiac fibrosis. Female Wistar rats ( n = 48) were assigned into two groups: ovariectomized (Ovx; 10-wk-old) and control rats (Sham; 10-wk-old). Each group was further divided into two subgroups, sedentary and trained (aerobic training by swimming for 10 wk). The sedentary groups showed similar cardiac autonomic tone values; however, only the Sham group had an increase in vagal participation for the determination of the basal heart rate after physical training. The contractile responses to cardiac β-agonists of the sedentary groups were similar, including an increased response to a β1-agonist (dobutamine) observed after physical training. The Ovx sedentary group presented changes in cardiac morphology, which resulted in decreases in the ejection fraction, fractional shortening, and cardiac index compared with the Sham sedentary group. Physical training did little to alter these findings. Moreover, histology analysis showed a significant increase in cardiac fibrosis in the sedentary Ovx group, which was not observed in the trained Ovx group. We conclude that early ovarian hormone deprivation in rats impairs autonomic control, cardiac morphology, and cardiac function and increases cardiac fibrosis; however, it does not affect the contractility induced by dobutamine and salbutamol. Furthermore, this model of physical training prevented an increase in fibrosis and promoted an increase in the cardiac contractile response but had little effect on cardiac autonomic control or morphological and functional parameters.

Effects of biological sex on the pathophysiology of the heart

Cardiovascular diseases are the leading causes of death in men and women in industrialized countries. While the effects of biological sex on cardiovascular pathophysiology have long been known, the sex-specific mechanisms mediating these processes have been further elucidated over recent years. This review aims at analysing the sex-based differences in cardiac structure and function in adult mammals, and the sex-based differences in the main molecular mechanisms involved in the response of the heart to pathological situations. It emerged from this review that the sex-based difference is a variable that should be dealt with, not only in basic science or clinical research, but also with regards to therapeutic approaches.

Estrogen therapy, independent of timing, improves cardiac structure and function in oophorectomized mRen2.Lewis rats

OBJECTIVE

mRen2.Lewis rats exhibit exacerbated increases in blood pressure, left ventricular (LV) remodeling, and diastolic impairment after the loss of estrogens. In this same model, depletion of estrogens has marked effects on the cardiac biopterin profile concomitant with suppressed nitric oxide release. With respect to the establishment of overt systolic hypertension after oophorectomy (OVX), we assessed the effects of timing long-term 17β-estradiol (E2) therapy on myocardial function, myocardial structure, and the cardiac nitric oxide system.

METHODS

OVX (n = 24) or sham operation (Sham; n = 13) was performed in 4-week-old female mRen2.Lewis rats. After randomization, OVX rats received E2 immediately (OVX + E2-early; n = 7), E2 at 11 weeks of age (OVX + E2-late; n = 8), or no E2 at all (OVX; n = 9).

RESULTS

E2-early was associated with lower body weight, less hypertension-related cardiac remodeling, and decreased LV filling pressure compared with OVX rats without E2 supplementation. E2-late similarly attenuated the adverse effects of ovarian hormone loss on tissue Doppler-derived LV filling pressures and perivascular fibrosis, and significantly improved myocardial relaxation or mitral annular velocity (e'). Early and late exposures to E2 decreased dihydrobiopterin, but only E2-late yielded significant increases in cardiac nitrite concentrations.

CONCLUSIONS

Although there are some similarities between E2-early and E2-late treatments in relation to preservation of diastolic function and cardiac structure after OVX, the lusitropic potential of E2 is most consistent with late supplementation. The cardioprotective effects of E2-late are independent of blood pressure and may have occurred through regulation of cardiac biopterins and nitric oxide production.

Effects of estrogen via estrogen receptors on parvalbumin levels in cardiac myocytes of ovariectomized rats

The study investigated the effects of estrogen on parvalbumin (PV) levels in cardiac myocytes of ovariectomized rats, which is a model system for postmenopausal woman. Parvalbumin acts as a relaxing factor in cardiac myocytes. Adult female Wistar rats, 12 weeks old, were randomly divided into 5 groups of 10: sham-operated (SHAM), ovariectomized (OVX), and OVX receiving estrogen replacement of 10 μg/kg (Es10), 20 μg/kg (Es20) and 40 μg/kg (Es40). After 10 weeks, serum estrogen levels were measured and the α and β estrogen receptors in cardiac myocytes were investigated by immunohistochemistry. PV levels were examined by immunohistochemistry and Western blot analysis. Cardiac myocytes of all animals showed strong staining intensities for α immunoreactive (Es α-ir), but weak staining for β immunoreactive (Es β-ir) estrogen receptors. The Es α-ir was reduced in the cardiac myocytes of the OVX groups, but increased in the Es10, Es20 and Es40 groups. We therefore suggest that estrogen effects are mediated via Es α receptors rather than Es β receptors in female rat hearts. Estrogen and PV immunoreactive (PV-ir) levels and the intensity of the PV band observed in the OVX group were less than those of the SHAM group. In the Es10, Es20 and Es40 groups, the increased intensity of the PV-ir and PV bands correlated with the increased estrogen levels. The low PV levels in cardiac myocytes induced by low estrogen were restored by estrogen replacement therapy. Therefore a reduction of PV may lead to diastolic dysfunction in menopause.

Myocardial contractility is preserved early but reduced late after ovariectomy in young female rats

BACKGROUND

Ovarian sex hormones (OSHs) are implicated in cardiovascular function. It has been shown that OSHs play an important role in the long term regulation of cardiac sarcoplasmic reticulum (SR) function and contractility, although early effects of OSHs deprivation on myocardial contractility have not yet been determined. This study evaluated the early and late effects of OSHs deficiency on left ventricular contractility in rats after ovariectomy.

METHODS

Young female Wistar rats were divided into 3 groups (n=9-15): sham operated (Sham), ovariectomized (Ovx) and Ovx treated with estradiol (1 mg/kg, i.m., once a week) (Ovx+E2). After 7, 15, 30 and 60 days post Ovx, left ventricle papillary muscle was mounted for isometric tension recordings. The inotropic response to Ca2+ (0.62 to 3.75 mM) and isoproterenol (Iso 10-8 to 10-2 M) and contractility changes in response to rate changes (0.25 to 3 Hz) were assessed. Protein expression of SR Ca2+-ATPase (SERCA2a) and phospholamban (PLB) in the heart was also examined.

RESULTS

The positive inotropic response to Ca2+ and Iso at 7, 15, and 30 days after Ovx was preserved. However, at 60 days, the Ovx group had decreased myocardial contractility which was subsequently restored with E2 replacement. The reduction in SERCA2a and increase in PLB expression observed at 60 days after Ovx were restored with E2 replacement.

CONCLUSION

This study demonstrated that myocardial contractility and expression of key Ca2+ handling proteins were preserved in the early phase and reduced at long-term during OSHs deprivation.

Increased myocardial stiffness with maintenance of length-dependent calcium activation by female sex hormones in diabetic rats

A decrease in peak early diastolic filling velocity in postmenopausal women implies a sex hormone-related diastolic dysfunction. The regulatory effect of female sex hormones on cardiac distensibility therefore was evaluated in ovariectomized rats by determining the sarcomere length-passive tension relationship of ventricular skinned fiber preparations. Diabetes also was induced in the rat to assess the protective significance of female sex hormones on diastolic function. While ovariectomy had no effect on myocardial stiffness, collagen content, or titin ratio, a significant increase in myocardial stiffness was observed in diabetic rat only when female sex hormones were intact. The increased stiffness in diabetic-sham rats was accompanied by an elevated collagen content resulting from increases in the levels of procollagen and Smad2. Surprisingly, the increased myocardial stiffness in diabetic-sham rats was accompanied by a shift toward a more compliant N2BA of cardiac titin isoforms. The pCa-active tension relationship was analyzed at fixed sarcomere lengths of 2.0 and 2.3 μm to determine the magnitude of changes in myofilament Ca(2+) sensitivity between the two sarcomere lengths. Interestingly, high expression of N2BA titin was associated with a suppressed magnitude of changes in myofilament Ca(2+) sensitivity only in the diabetic-ovariectomized condition. Estrogen supplementation in diabetic-ovariectomized rats partially increased myocardial stiffness but completely reversed the change in myofilament Ca(2+) sensitivity. These results indicate a restrictive adaptation of myocardium governed by female sex hormones to maintain myofilament activity in compensation to the pathophysiological induction of cardiac dilatation by the diabetic condition.

The effects of hormone replacement therapy on myocardial performance in early postmenopausal women

OBJECTIVES

The results of the studies in which the effect of hormone replacement therapy (HRT) on cardiac function have been evaluated are rather disputable. In these studies, cardiac function was evaluated with conventional echocardiographic methods. This study was planned in order to investigate the effects of HRT on myocardial velocities and myocardial performance index (MPI) in healthy early postmenopausal women.

METHOD

In a prospective, controlled study, 60 healthy postmenopausal women were assigned to two groups (32 in the HRT group and 28 in the control group). After conventional echocardiographic parameters were measured, tissue Doppler echocardiography recordings were obtained from the mitral and tricuspid annulus. Systolic myocardial velocity (Sm), early and late diastolic myocardial velocities (Em and Am) and time intervals were measured and MPI was calculated. Then the symptom-limited exercise stress test using the Bruce protocol was performed. After 3 and 6 months of HRT (oral 0.625 mg conjugated estrogen + 2.5 mg medroxyprogesterone acetate/day), the same examinations were repeated. The effects of HRT on myocardial velocities, MPI and exercise time were evaluated at the 3rd and 6th months.

RESULTS

The parameters of the control group remained statistically unchanged during the study. HRT did not have any effect on segmental and mean left ventricular (LV) Sm or right ventricular (RV) Sm. However, LV Em/Am and RV Em/Am ratios significantly increased at the 6th month of HRT, and LV and RV MPI values were observed to decrease significantly as compared to basal values. Additionally, a significant increase was observed in exercise duration and metabolic equivalent values after 3 months of HRT, and this increase continued at the 6th month as well. The favorable changes in all parameters in the HRT group were significantly different from those of the control group.

CONCLUSION

Data obtained in this study suggest that HRT is not only effective for treating menopausal complaints but also increases cardiovascular performance by improving especially diastolic functions in early postmenopausal women.

Moderate intensity of regular exercise improves cardiac SR Ca2+ uptake activity in ovariectomized rats

The impact of regular exercise in protecting cardiac deteriorating results of female sex hormone deprivation was evaluated by measuring changes in intracellular Ca2+ removal activity of sarcoplasmic reticulum (SR) in ovariectomized rats following 9-wk treadmill running exercise at moderate intensity. Despite induction of cardiac hypertrophy in exercised groups of both sham-operated and ovariectomized rats, exercise training had no effect on SR Ca2+ uptake and SR Ca(2+)-ATPase (SERCA) in hormone intact rat heart. However, exercise training normalized the suppressed maximum SR Ca2+ uptake and SERCA activity in ovariectomized rat heart. While exercise training normalized the leftward shift in pCa (-log[Ca2+])-SR Ca2+ uptake relation in ovariectomized rats, no effect was detected in exercised sham-operated rats. Similar phenomena were also observed on SERCA and on phospholamban (PLB) phosphorylation levels; exercise training in ovariectomized rats enhanced SERCA expression to reach the level as that in sham-operated rats, in which there were no differences in SERCA and phospho-PLB levels between sedentary and exercised groups. In addition, the reduction in phospho-Thr(17) PLB in myocardium of ovariectomized rats was abolished by exercise training. These results showed that regular exercise maintains the molecular activation of cardiac SR Ca2+ uptake under normal physiological conditions and is able to induce a protective impact on cardiac SR Ca2+ uptake in ovarian sex hormone-deprived status.

Raloxifene has favourable effects on metabolic parameters but has no effect on left ventricular function in postmenopausal women

In this prospective randomized study, we investigated the effect of raloxifene on the echocardiographic parameters of left ventricular diastolic and systolic function and on blood levels of lipids, homocysteine, and lipoprotein (a) in postmenopausal osteoporotic patients and compared the results with those treated with risedronate. A total of 44 women were included in the study. Patients were randomized into two groups. Twenty-two patients received raloxifene 60 mg/day (group 1), and 22 patients received risedronate 5mg/day (group 2; the control group). All patients underwent quantitative two-dimensional pulsed wave Doppler and tissue Doppler echocardiography. Levels of fasting total-C, HDL-C, LDL-C, triglycerides, homocysteine, and lipoprotein (a) were measured. All echocardiographic and biochemical parameters were assessed at the beginning of the study and after the 6-month follow-up. Demographic characteristics and baseline metabolic and echocardiographic parameters were similar in the two groups. After 6 months of the therapy, serum levels of total-C, LDL-C, and homocysteine decreased significantly (P=.04, P=.02, P=.008, respectively) in the treated group when compared with the control group. All echocardiographic measurements except a wave from level of basal interventricular septum were similar in the two groups both before and after 6 month of therapy. In the control group, a wave from level of basal interventricular septum increased significantly (P=.019). In conclusions raloxifene may decrease serum levels of total-C, LDL-C, and homocysteine in postmenopausal osteoporotic patients and raloxifene therapy seems to have no significant effect on left ventricular systolic and diastolic function.

Effects of estradiol alone and combined with norethisterone acetate on pulse-wave velocity in hypertensive postmenopausal women

BACKGROUND

Arterial hypertension and postmenopausal reduction of estrogen levels may be involved in modifications of the stiffness of large arteries.

OBJECTIVES

To evaluate the pulse-wave velocity (PWV) and indirectly the arterial stiffness in hypertensive postmenopausal women submitted to hormone therapy with estradiol alone or combined with norethisterone acetate.

SUBJECTS

Forty-five hypertensive postmenopausal women were double-blindly, randomly assigned to three arms of treatment: placebo (group I); estradiol 2 mg/day (group II); or estradiol 2 mg/day and norethisterone acetate 1 mg/day (group III).

METHODS

Arterial stiffness was assessed from PWV measurements of the common carotid and femoral arteries (CF-PWV) and the common carotid and radial arteries (CR-PWV) obtained using the automatic Complior(R) device, taken at baseline and after 12 weeks of treatment.

RESULTS

After the 12-week treatment, values of CF-PWV and CR-PWV were not significantly different (p = 0.910 and p = 0.736, respectively) among the groups. Systolic blood pressure showed a positive correlation with CF-PWV in groups II and III (p = 0.02 and p < 0.001, respectively).

CONCLUSIONS

PWV and arterial stiffness in postmenopausal hypertensive women did not reduce over a 12-week treatment with estradiol alone compared with the same period of treatment with estradiol combined with norethisterone acetate.

Meta-analysis: effect of hormone-replacement therapy on components of the metabolic syndrome in postmenopausal women

AIM

To quantify the effects of hormone-replacement therapy (HRT) on components of the metabolic syndrome in postmenopausal women.

METHODS

Comprehensive searches of electronic databases were performed from April 1966 to October 2004. We included randomized controlled trials that were of at least 8 weeks duration and evaluated the effect of HRT on metabolic, inflammatory or thrombotic components. Insulin resistance was calculated by homeostasis model assessment (HOMA-IR). Subgroup analysis evaluated the effects for transdermal and oral treatment and for diabetic and non-diabetic women.

RESULTS

Pooled results of 107 trials showed that HRT reduced abdominal fat [-6.8% (CI, -11.8 to -1.9%)], HOMA-IR [-12.9% (CI, -17.1 to -8.6%)] and new-onset diabetes [relative risk 0.7 (CI, 0.6-0.9)] in women without diabetes. In women with diabetes, HRT reduced fasting glucose [-11.5% (CI, -18.0 to -5.1%)] and HOMA-IR [-35.8% (CI, -51.7 to -19.8%)]. HRT also reduced low-density lipoprotein/high-density lipoprotein cholesterol ratio [-15.7% (CI, -18.0 to -13.5%)], lipoprotein(a) [Lp(a)] [-25.0% [CI, -32.9 to -17.1%)], mean blood pressure [-1.7% (CI, -2.9 to -0.5%)], E-selectin [-17.3% (CI, -22.4 to -12.1%)], fibrinogen [-5.5% (CI, -7.8 to -3.2%)] and plasminogen activator inhibitor-1 [-25.1% (CI, -33.6 to -15.5%)]. Oral agents produced larger beneficial effects than transdermal agents, but increased C-reactive protein (CRP) [37.6% (CI, 17.4-61.3%)] and decreased protein S [-8.6% CI, -13.1 to -4.1%)], while transdermal agents had no effect.

CONCLUSIONS

HRT reduces abdominal obesity, insulin resistance, new-onset diabetes, lipids, blood pressure, adhesion molecules and procoagulant factors in women without diabetes and reduced insulin resistance and fasting glucose in women with diabetes. Oral agents adversely affected CRP and protein S, while transdermal agents had no effects.

Effect of estrogen on calcium-handling proteins, β-adrenergic receptors, and function in rat heart

Regulation of cellular Ca(2+) cycling is central to myocardial contractile function. Loss of Ca(2+) regulation is associated with cardiac dysfunction and pathology. Estrogen has been shown to modify contractile function and to confer cardioprotection. Therefore, we investigated the effect of estrogen on expression of rat heart myocardial Ca(2+)-handling proteins and beta-adrenergic receptor (beta(1)-AR) and examined functional correlates. Female rats were sham-operated (SHAM) or ovariectomized. Two weeks after ovariectomy rats were injected (i.p.) daily with estradiol benozoate (OVX+EB) or sesame oil (OVX) for 2 weeks. Protein abundance was measured by immunoblotting and mRNA was quantified by real-time RT-PCR. OVX significantly decreased estrogen and progesterone levels and EB replacement returned both estrogen and progesterone to physiological levels. OVX induced a 75% reduction of uterine weight and a gain in body weight. Replacement restored weights to SHAM level. OVX increased and estrogen-replacement normalized abundance of beta(1)-AR and L-type Ca(2+) channel (Cav1.2) protein. OVX decreased sodium-Ca(2+) exchange protein (NCX) and estrogen restored protein abundance to SHAM levels. Sarcoplasmic reticular ATPase (SERCA), phospholamban (PLB), and ryanodine receptor (RyR) abundance was not altered by hormone status. Levels of mRNA encoding for beta(1)-AR, Cav1.2, and NCX were not influenced by OVX or estrogen replacement. OVX had no effect on SERCA and PLB mRNA level but estrogen replacement elicited a significant increase compared to OVX and SHAM. Estrogen-dependent changes in Ca(2+)-handling proteins and beta(1)-AR are theoretically consistent reduced myocellular Ca(2+) load. However, hormone-dependent alterations in protein were not associated with changes in contractile function.

Estrogen depletion differentially affects blood pressure depending on age in Long-Evans rats

Normotensive female rats exhibit age-related decreases in estrous cyclicity and increases in blood pressure. In spontaneously hypertensive rats, estrogens, including dietary phytoestrogens, prevent or attenuate the increased blood pressure associated with estrogen depletion. The present studies examine the effects of ovariectomy (OVX) at either 3 or 10 mo of age. Although blood pressure increases from 3 to 9 mo, OVX at 3 mo of age has no added effect--despite the fact that OVX (compared to ovary-intact) rats weighed significantly more. In contrast, aging from 10 to 16 mo is associated with a further increase in blood pressure, which is potentiated by estrogen depletion. Removal of dietary phytoestrogens exacerbated the hypertensive effects of OVX in these middle-aged rats. As in younger rats, estrogen depletion at 10 mo of age was associated with greater weight gain. Whereas estrogen depletion at 3 mo of age was without effect on fluid intake over the next 6 mo, OVX at 10 mo of age was associated with decreased fluid intake. In a final study, rats were OVX at 3 mo of age with estradiol (E2) treatment initiated at 10 mo of age. Long-term OVX ( >10 mo) was associated with increased blood pressure and mortality at 14-16 mo of age. Circulating levels of E2 were decreased by OVX. Plasma aldosterone was increased by OVX, an effect which was prevented by either E2 or phytoestrogens. Neither E2 nor aldosterone was affected by age. These data indicate that (a) the physiological effects of estrogen depletion vary with age; (b) phytoestrogens in the diet exert some protective effects; and (c) long-term OVX in the absence of hormone re-placement is associated with premature mortality. We suggest that chronic increases in aldosterone and sympathetic tone underlie the hypertensive effects of estrogen depletion.