The effect of hormone replacement therapy on diastolic left ventricular function in hypertensive and normotensive postmenopausal women

Sex differences in preclinical models of hypertension

Hypertension remains the primary contributor in the development of cardiovascular disease which is rapidly increasing worldwide. High blood pressure affects men and women differently and understanding these sex differences is the ultimate unmet need for researchers in this field. Due to the inherent differences in hypertension prevalence, control and outcomes between men and women, novel research needs to be carried out to tackle these disparities and improve targeted treatment. Animal models of hypertension have provided valuable insights into the sexual dimorphism of blood pressure mechanisms. The availability of genetic and non-genetic hypertensive strains allows the opportunity to study diverse environmental and genetic factors that affect blood pressure, therefore presenting a valuable tool for researchers. Sex differences are present before birth and throughout life, which presents a challenge for the study of disease development in humans, but these complexities can be resolved with the use of in vivo models that display similarities to human disease. The aim of the present review is to provide an overview of the different available animal models of hypertension that present sexual dimorphisms and to discuss their relevance to humans.

Early Left Ventricular Diastolic Dysfunction in Females with Chronic Hyperprolactinemia: A Doppler Echocardiographic Study

Despite the myocardial prolactin (PRL) binding activity and the known effect of enhancing contractility in the isolated rat heart, little information is available concerning the cardiovascular consequences of hyperprolactinemia in humans. To elucidate the effects of chronic hyperprolactinemia on cardiac structure and function, twenty-four patients with isolated PRL-secreting adenoma and twenty-four controls underwent a complete mono- and two-dimensional Doppler-echocardiography. Blood pressure and heart rate were similar in the two groups, and no significant differences were observed as to left ventricular (LV) geometry between patients and controls. Resting LV systolic function was normal in patients with hyperprolactinemia, as shown by similar values of fractional shortening and cardiac output. Conversely, hyperprolactinemic patients exhibited a slight impairment of LV diastolic filling, as demonstrated by the prolongation of the isovolumetric relaxation time and the increase of the atrial filling wave of mitral Doppler velocimetry (58 ± 13 vs. 47 ± 8 cm/s, p < 0.05) with a subgroup of females (16%) having a clear diastolic dysfunction, and a worse exercise capacity (6 min walking test 452 ± 70 vs. 524 ± 56; p < 0.05). In conclusion, hyperprolactinemia in humans may be associated with a slight impairment of diastolic function, with an overt diastolic dysfunction in a subgroup of females which correlated with poorer exercise performance, in the absence of significant abnormalities of LV structure and systolic function.

A heartfelt message, estrogen replacement therapy: use it or lose it

The issue of cardiovascular and cognitive health in women is complex. During the premenopausal phase of life, women have healthy blood pressure levels that are lower than those of age-matched men, and they have less cardiovascular disease. However, in the postmenopausal stage of life, blood pressure in women increases, and they are increasingly susceptible to cardiovascular disease, cognitive impairments, and dementia, exceeding the incidence in men. The major difference between pre- and postmenopausal women is the loss of estrogen. Thus, it seemed logical that postmenopausal estrogen replacement therapy, with or without progestin, generally referred to as menopausal hormone treatment (MHT), would prevent these adverse sequelae. However, despite initially promising results, a major randomized clinical trial refuted the benefits of MHT, leading to its falling from favor. However, reappraisal of this study in the framework of a "critical window," or "timing hypothesis," has changed our perspective on the benefit-to-risk ratio of MHT, and this review discusses the historical, current, and future approaches to MHT.

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.

Effect of hormone replacement therapy on lipids and left ventricular function in postmenopausal smokers

OBJECTIVE

Menopause and smoking have negative effects on the cardiovascular system. The study was planned to investigate the influence of oral hormone replacement therapy (HRT) on heart function and lipids in postmenopausal smokers.

METHODS

Lipid levels and left ventricular systolic and diastolic function by means of echocardiography were assessed before entering the study and at 6-month intervals during the 12 months of oral HRT in 62 postmenopausal women, 30 of whom were smokers and 32 were non-smokers.

RESULTS

Oral HRT caused a significant decrease in levels of total cholesterol and low density lipoprotein (LDL) cholesterol and a significant increase in high density lipoprotein (HDL) cholesterol in non-smokers. This effect was not evident in smokers. Echocardiography revealed a significant improvement of systolic function (ejection fraction, left ventricular outflow tract velocity, forward velocity integral, acceleration time and mean systolic acceleration) and diastolic function (diastolic time, duration of the early filling phase, peak velocity of early mitral flow, and the ratio of late to early peak mitral flow) in non-smokers. In smokers, a significant increase in some parameters of systolic function (ejection fraction, acceleration time and mean systolic acceleration) and an insignificant change in diastolic function were observed. Oral HRT of 12 months' duration has very limited beneficial effects on

CONCLUSION

lipids and left ventricular heart function in postmenopausal women who smoke.

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.

Mesenteric arterial relaxation to calcitonin gene-related peptide is increased during pregnancy and by sex steroid hormones

The present study investigated whether pregnancy and circulatory ovarian hormones increase the sensitivity of the mesenteric artery to calcitonin gene-related peptide (CGRP)-induced relaxation and possible mechanisms involved in this process. Mesenteric arteries from young adult male rats or female rats (during estrous cycle, after ovariectomy, at Day 20 of gestation, or Postpartum Day 2) were isolated, and the responsiveness of the vessels to CGRP was examined with a small vessel myograph. The CGRP (10(-10) to 10(-7) M) produced a concentration-dependent relaxation of norepinephrine-induced contractions in mesenteric arteries of all groups. Arterial relaxation sensitivity to CGRP was significantly (P < 0.05) greater in female rats compared with male rats. Pregnancy increased the sensitivity to CGRP significantly (P < 0.05) compared to ovariectomized and Postpartum Day 2 rats. In pregnant rats, CGRP-receptor antagonist, CGRP(8-37), inhibited the relaxation responses produced by CGRP. The CGRP-induced relaxation was not affected by N(G)-nitro-l-arginine methyl ester (nitric oxide inhibitor, 10(-4) M) but was significantly (P < 0.05) attenuated by an inhibitor of guanylate cyclase (1H-[1 , 2 , 4 ]oxadizaolo[4 , 3 -a]quinoxalin-1-one, 10(-5) M). Relaxation responses of CGRP on mesenteric arteries were blocked (P < 0.05) by a cAMP-dependent protein kinase A inhibitor, Rp-cAMPs (10(-5) M). The CGRP-induced vasorelaxation was significantly (P < 0.05) attenuated by calcium-dependent (tetraethylammonium, 10(-3) M), but not ATP-sensitive (glybenclamide, 10(-5) M), potassium channel blocker. Therefore, the results of the present study suggest that mesenteric vascular sensitivity to CGRP is higher during pregnancy and that cAMP, cGMP, and calcium-dependent potassium channels appear to be involved. Therefore, we propose that CGRP-mediated vasodilation may be important to maintain vascular adaptations during pregnancy.

Effects of aging on cardiovascular responses to parasympathetic withdrawal

OBJECTIVES

The study was done to determine whether the effects of parasympathetic withdrawal on heart rate, blood pressure (BP), and systolic and diastolic function are altered with normal aging.

BACKGROUND

Cardiac responses to beta-adrenergic sympathetic stimulation decline with aging as does the heart rate response to parasympathetic withdrawal, but the extent to which other responses to parasympathetic withdrawal decrease is less clear.

METHODS

Heart rate, BP, systolic function, and diastolic filling responses to parasympathetic withdrawal induced by atropine (0.02 mg/kg) were compared in 50 healthy subjects, 28 older (ages 65 to 80 years, mean 70 years; 18 females all on estrogen) and 22 young (age 18 to 32 years, mean 26 years; 12 females) subjects, using radionuclide angiography.

RESULTS

Parasympathetic withdrawal in the older group caused less of an increase in heart rate (+33 vs. +48 beats/min), cardiac index (+0.6 vs. +1.5 l/m(2)), systolic blood pressure (-1 vs. +7 mm Hg), and early diastolic filling rate (+1.7 vs. +2.4 end-diastolic volumes/s) (all p < or = 0.01). At similar declines in the diastolic filling period, end-diastolic volume index (EDVI) fell substantially more in the older group (-11.6 vs. -2.4 ml/m(2), p < 0.001). The only gender difference was in diastolic filling rate, which was similar in the young males and females, but significantly less in older males than in older females.

CONCLUSIONS

The responses to parasympathetic withdrawal as well as sympathetic stimulation decline with aging, and both contribute to the reduced cardiovascular responses to stress with advancing age.

Left ventricular diastolic function assessment by tissue Doppler echocardiography in relation to hormonal replacement therapy in postmenopausal women with diastolic dysfunction

The objective of this study was to evaluate the effect of hormone replacement therapy (HRT) regimens on left ventricular diastolic function by using mitral pulsed wave Doppler (MPWD) and tissue Doppler velocities (TDE). Seventy-eight postmenopausal women with normotensive and impaired diastolic left ventricular filling were included in the study. All the patients began a six-cycle HRT course. This formulation consisted of E2 valerate plus Medroxy progesterone acetate (MPA). Left ventricular diastolic function at rest was evaluated by M-mode, two-dimensional, MPWD and TDE in 78 postmenopausal women with normal blood pressure before the treatment for 6 months of HRT. The M-mode, two-dimensional, and MPWD parameters assessed were heart rate, systolic blood pressure, diastolic blood pressure, left ventricular mass index, ejection fraction of the left ventricle (EF), septal (IVS) and posterior wall (PW) thickness, left ventricular end-systolic (LVESD) and end-diastolic (LVEDD) diameter, left atrial diameter, peak early diastolic velocity (E), peak atrial velocity (A), E/A ratio, E acceleration time, E deceleration time, diastolic filling period, and isovolumic relaxation time (IVRT). The TDE parameters assessed were peak early diastolic velocity (E'), peak late diastolic velocity (A'), peak systolic velocity, E'/A' ratio, E' acceleration time, E' deceleration time, IVRT', and E/E' ratio. Quantitative data were analyzed using Student t test. Among the MPWD parameters, peak A velocity, E deceleration time, and IVRT significantly decreased, while peak E velocity and E/A ratio increased after a 6-month treatment. From the point of TDE parameters, E' velocity and E'/A' ratio increased, while A' velocity, E' deceleration time, E/E' ratio and IVRT' decreased. Some MPWD and TDE parameters were partially reversed after HRT. TDE velocities and especially E/E' ratio may provide better and true information of the diastolic function. TDE parameters were independent from the preload and did not produce pseudonormal pattern. HRT may cause increase in the blood volume and produce pseudonormal pattern in transmitral flow. In that case, TDE may be a beneficial method for evaluation of diastolic function.

Neither long-term treatment with raloxifene nor hormone replacement therapy modulate cardiac function in healthy postmenopausal women: two randomized, placebo-controlled, 2-year studies

OBJECTIVE

Our purpose was to investigate the long-term effects of raloxifene, compared with opposed and unopposed estrogen replacement therapy, on echocardiographic parameters of left ventricular systolic function in healthy postmenopausal women. A total of 157 women were studied in 2 randomized, double-blind, placebo-controlled, 2-year studies.

STUDY DESIGN

In study I, 60 postmenopausal women who had undergone hysterectomy received daily raloxifene, 60 mg (n = 15); raloxifene, 150 mg (n = 15); conjugated equine estrogens (CEE), 0.625 mg (n = 15); or placebo (n = 15). In study II, 97 postmenopausal women who had not undergone hysterectomy received daily raloxifene, 60 mg (n = 24); raloxifene, 150 mg (n = 24); CEE, 0.625 mg, plus medroxyprogesterone acetate (MPA), 2.5 mg (n = 24); or placebo (n = 25). M-mode, quantitative 2-dimensional and Doppler echocardiographic measurements were performed at baseline and after 1 and 2 years.

RESULTS

Neither after 1 year nor after 2 years of treatment were echocardiographic parameters found to differ from baseline in both raloxifene groups, as well as in the unopposed CEE and the CEE/MPA groups, compared with the placebo group.

CONCLUSION

Within 2 years of raloxifene treatment, no effect on echocardiographic parameters of left ventricular systolic function was found. Unopposed CEE or CEE/MPA also showed no effect.

Resistive index of renal artery and blood pressure in postmenopausal women

Causal association between perimenopausal changes and symptoms and disease is commonly accepted even if not definitely explained. Resistive index (RI) of renal artery assessed by Doppler echography is related to renal function and systemic circulatory adaptation in patients with chronic renal failure and hypertension. Echocardiographic measurement of left ventricular myocardial mass (LVMM) is a useful tool for assessing effects of arterial hypertension on heart. Aim of the study was to assess RI in normotensive postmenopausal women and relationship, if any, with blood pressure and LVMM. We studied 28 normotensive, non-obese postmenopausal women, age 52.21 +/- 5.40 years, with normal creatinine clearance. Renal colour-Doppler echography was performed assessing intra-parenchimal renal artery mean velocity (mVRA) and intra-parenchimal RI [(peak systolic velocity - end diastolic velocity)/peak systolic velocity]. Echocardiography was performed as well. RI of intra-parenchimal renal artery is 0.67 +/- 0.05 and it shows correlations vs. diastolic blood pressure (r=0.41; P<0.03) and vs. mean BP (r=0.47; P<0.01). LVMM has correlation (r=0.41; P>0.03) with RI. Age, body weight, body mass index, menarche age, fertility years and postmenopausal years do not show correlation with RI. Heart rate, creatinine clearance, hemoglobin, serum albumin do not show any correlation with RI. Higher RI is associated with alcohol intake, liver steatosis, biliary gallstones and family history of diabetes mellitus, but not with postmenopausal years, unrespective of surgical or non-surgical menopause. Among echocardiographic measurements only LVMM is correlated with RI; mVRA does not show correlation. LVMM and BP do not show other independent correlation except that the one already reported vs. RI. RI, as a pathophysiological measurement whose increase preludes to arterial hypertension, could help to ascertain perimenopausal women at risk for arterial hypertension and left ventricular hypertrophy, but does not seem directly associated with the loss of ovarian function.

Effects of hormonal replacement therapy in postmenopausal hypertensive patients

OBJECTIVE

To evaluate the effect of hormonal replacement therapy (HRT) on blood pressure (BP) in postmenopausal hypertensive women.

METHODS

Sixty women affected by hypertension were enrolled and randomized in two groups of treatment: transdermal continuous HRT in a sequential regimen (group A) and placebo (group P). At baseline, after 3 and 6 months of treatment, the BP with standard sphygmomanometer and with 24-h ambulatory recording method was evaluated in two periods (from day 10 through day 16 of the cycle and from day 20 through day 27 of the cycle). At the same time, we also evaluated total cholesterol, LDL-c, HDL-c, triglycerides, and fibrinogen levels.

RESULTS

After 3 and 6 months of treatment, no significant variations of systolic and diastolic BP measured with standard sphygmomanometer were detected in both groups. On the contrary, in group A in comparison with basal values and group P, and without difference between the two phases of treatment, the 24-h recording showed a significant (P<0.05) decrease in BP. No significant variations were detected in group P versus baseline. In particular, we observed in group A at 3 months of treatment a significant (P<0.05) decrease only in daytime BP in comparison with basal values and group P, without difference between the two phases of treatment. Indeed, the decrease in daytime BP was significant (P<0.05) for both systolic and diastolic BP. At 3 and 6 months a significant (P<0.05) decrease in total cholesterol, LDL-c and fibrinogen levels was detected in group A versus baseline and group P. HDL-c and triglyceride concentrations showed no significant variations.

CONCLUSIONS

The transdermal HRT induces a significant reduction of BP values and a favorable metabolic action in postmenopausal hypertensive patients.

Gender differences in the regulation of blood pressure

Men are at greater risk for cardiovascular and renal disease than are age-matched, premenopausal women. Recent studies using the technique of 24-hour ambulatory blood pressure monitoring have shown that blood pressure is higher in men than in women at similar ages. After menopause, however, blood pressure increases in women to levels even higher than in men. Hormone replacement therapy in most cases does not significantly reduce blood pressure in postmenopausal women, suggesting that the loss of estrogens may not be the only component involved in the higher blood pressure in women after menopause. In contrast, androgens may decrease only slightly, if at all, in postmenopausal women. In this review the possible mechanisms by which androgens may increase blood pressure are discussed. Findings in animal studies show that there is a blunting of the pressure-natriuresis relationship in male spontaneously hypertensive rats and in ovariectomized female spontaneously hypertensive rats treated chronically with testosterone. The key factor in controlling the pressure-natriuresis relationship is the renin-angiotensin system (RAS). The possibility that androgens increase blood pressure via the RAS is explored, and the possibility that the RAS also promotes oxidative stress leading to production of vasoconstrictor substances and reduction in nitric oxide availability is proposed.

Hypothesis: pulse pressure and human longevity

In exploration of the association between pulse pressure and longevity in humans, 3 hypotheses are briefly discussed: the fetal origin hypothesis, antagonistic pleiotropy, and the telomere hypothesis of cellular aging. The implications of these hypotheses serve to draw a critical distinction between biologic age (aging) and chronological age and, thereby, offer an answer to a question that presently matters most in the field of hypertension: Why has it been so difficult to disentangle the genetic components of essential hypertension and to identify the variant genes responsible for elevated blood pressure in a large segment of the human population?

Hormone replacement improves hemodynamic profile and left ventricular geometry in hypertensive and normotensive postmenopausal women

BACKGROUND

Postmenopausal estrogen replacement, with or without progestins, has been related to lower cardiovascular risks.

OBJECTIVE

We investigated whether the actions of estrogen on vascular resistance contribute to this cardioprotective effect.

DESIGN AND METHODS

In a 6-month double-blind study, pre- and post-treatment blood pressure, cardiac index, total vascular resistance index and plasma catecholamine responses during baseline and mental stressors were compared in 69 women (including 19 with mild hypertension but no history of heart disease). Women were randomized to receive either conjugated estrogens alone, estrogens plus medroxyprogesterone, or placebo.

RESULTS

Both groups on active hormone replacement showed similar decreases in vascular resistance and modest blood pressure reductions, which differed from the unchanged responses of those on placebo (P< 0.05) after 3 and 6 months of treatment. Hypertensive women showed greater reductions in vascular resistance than normotensives (P< 0.05) and their blood pressure reductions tended to be larger. Women receiving hormone replacement showed increased stroke volume and cardiac index at 6 months, particularly among hypertensives and those receiving medroxyprogesterone (P < 0.05). Hormone replacement was also related to decreases in plasma norepinephrine. Finally, in 33 women receiving hormone replacement, significant 5 and 3% decreases in echocardiographic measures of left ventricular mass index and relative wall thickness were evident at 6 months (P < 0.05), while 20 placebo-treated women showed no reliable echocardiographic improvements (P= NS).

CONCLUSIONS

These findings suggest that estrogen-mediated reductions in hemodynamic load on the heart may contribute to the reduced risk of cardiovascular events in relatively healthy postmenopausal women who use hormone replacement.

Female steroid hormones modulate receptors for nerve growth factor in rat dorsal root ganglia

Calcitonin gene-related peptide (CGRP) is a vasodilatory peptide, and it is primarily synthesized in dorsal root ganglia (DRG). Plasma CGRP levels increase during pregnancy and with steroid hormones, and nerve growth factor (NGF) stimulates calcitonin/CGRP promoter and CGRP synthesis in DRG. We previously showed that CGRP levels in DRG were stimulated with steroid hormone treatments in vivo but not in vitro. Thus, the stimulation of CGRP by these hormones may be indirect through the upregulation of NGF effects. We hypothesized that the female sex steroid hormones upregulate NGF receptors, trkA and p75(NTR), in DRG. We examined the effects of 17 beta-estradiol (E(2)) and progesterone (P(4)) on NGF receptors in DRG obtained from ovariectomized (ovx) rats. Groups of 4 ovx rats were injected s.c. with 5 microg E(2), 4 mg P(4), or 5 microg E(2) + 4 mg P(4) in 0.2 ml sesame oil or injected with oil only and were killed at 6, 24, and 48 h. In addition, ovx rats were also injected s.c. with varying doses (0.2, 1.0, 5.0, 25 microg) of E(2) (0.5, 1.5, 4, 10 mg) P(4), and (5 microg) E(2) + (0.5, 1.5, 4.0, 10 mg) P(4) in 0.2 ml sesame oil, or vehicle, and killed at 6 (for E(2)) or 24 (for P(4) and E(2) + P(4)) h. Furthermore, groups of ovx rats were also killed at 12 and 24 h; 3 and 7 days; 2, 4, and 6 wk after ovariectomy. The DRGs were collected from all groups and then processed for Western immunoblotting to examine both trkA and p75(NTR) levels. Estradiol increased trkA at 6 h but not p75(NTR). Progesterone caused upregulation of trkA and p75(NTR) at 6 and 24 h. 17 beta-Estradiol + P(4) increased trkA at 6 and 24 h and p75(NTR) at all time points examined. One microgram of E(2) increased trkA but did not affect p75(NTR) levels. Progesterone at 4 and 10 mg upregulated trkA but only 10 mg P(4) increased p75(NTR). Five micrograms of E(2) coinjected with P(4) at 1.5 and 4 mg increased trkA, while p75(NTR) receptor was upregulated when coinjected with P(4) at 1.5 to 10 mg. The ovariectomy caused a decrease in trkA receptors compared to proestrus rats, and these decreases were significant by 6 wk, but surprisingly p75(NTR) increased at 2 wk after ovariectomy. 17 beta-Estradiol increased trkA but not p75(NTR) receptors in DRG, whereas P(4) caused increases in both trkA and p75(NTR) in DRG. In addition, the combination of these steroid hormones had more effect on both receptors than either hormone alone. Thus, we concluded that high levels of female steroid hormones such as those due to pregnancy or hormonal replacement therapy could increase NGF receptor expression in DRG that carry more NGF to elevate the CGRP synthesis in these groups. We suggested that the regulation of NGF receptors by ovarian steroids may underlie steroidal regulation of other factors such as CGRP.

Postmenopausal hypertension

Cardiovascular disease is the leading cause of death in women and claims the lives of more than half a million women every year. Hypertension is one of the most prevalent and powerful contributors to atherosclerotic cardiovascular disease. Hypertension affects more men than women until 55 years of age, but after age 55, the percentage of women is higher. Estrogen deficiency has been linked to the rapid increase in cardiovascular disease in women who have undergone natural or surgical menopause. Hormone replacement therapy (HRT) has been shown to decrease the incidence of cardiovascular disease and, in some studies, to reduce blood pressure in postmenopausal women. However, little information is available on the effects of HRT on blood pressure in hypertensive postmenopausal patients. The cardioprotective effects of estrogens are not completely understood but may involve direct effects on blood vessels through modulation of endogenous vasoconstrictors and vasodilators and through reductions in serum lipoprotein and cholesterol levels. Experimental evidence suggests that estrogen increases the biological actions of nitric oxide and decreases the actions of angiotensin. After menopause, loss of the vascular protective effects of estrogens may unmask a population of women particularly prone to hypertension who would be at higher risk for cardiovascular disease.

The acute effects of sublingual estradiol on left ventricular diastolic function in normotensive and hypertensive postmenopausal women

AIM

limited information is available on estrogen influences on diastole. We aimed to investigate the acute effects of a single dose of sublingual 17beta-estradiol on left ventricular diastolic function in postmenopausal women.

METHODS

the study included 28 women aged 55.6 +/- 6 (15 normotensive and 13 hypertensive), who underwent Doppler echocardiography and estradiol plasma levels determination before and 60 min after sublingual administration of 4 mg of 17beta-estradiol.

RESULTS

there were no modifications in heart rate. Both systolic and diastolic blood pressure dropped significantly in the hypertensives and remained unchanged in normotensives. Estradiol levels were 1790 +/- 869 pg/ml in the normotensives and 2664 +/- 1490 in the hypertensives (P < 0.05). Peak early velocity, in the population as a whole, increased from 84 +/- 18 to 91 +/- 18 cm/s and the early-to-atrial velocity ratio from 1.1 +/- 0.4 to 1.4 +/- 0.6 (P < 0.0001 for both). Both acceleration and deceleration rates increased significantly (P < 0.0001). These changes were shared by all the patients. In addition, the hypertensive patients, who presented a baseline pattern characterized mainly by a grossly increased peak atrial velocity with reduction in the early-to-atrial velocity ratio, demonstrated a decrease in peak atrial velocity from 92 +/- 12 to 78 +/- 10 cm/s (P < 0.0001), associated with significant reductions in deceleration time (P < 0.0001) and pressure half time (P < 0.005). Therefore, the typical picture of impaired ventricular relaxation was favorably changed after estradiol administration.

CONCLUSIONS

the sublingual administration of estradiol induces acute modifications in left ventricular diastolic function in postmenopausal women, with improvement in the age-related left ventricular relaxation pattern, and that these beneficial changes are more pronounced in hypertensive that in normotensive women.

Lack of effects of transdermal estradiol on diastolic function: a randomized placebo-controlled double-blind short-term trial

OBJECTIVE

Limited information is available on the effects of transdermal estradiol on diastole. The present study was a randomized double-blind placebo-controlled trial designed to investigate the short-term effects of transdermal estradiol on left ventricular diastolic function in postmenopausal women.

METHODS

The study included 45 women aged 50.8 +/- 3.6 years (25 randomized to the study group and 20 to placebo), who underwent Doppler echocardiography and determination of the plasma estradiol level after 4 and 8 weeks of transdermal estradiol administration in a dose of 50 micrograms per 24 h.

RESULTS

There were no modifications in heart rate. Systolic blood pressure dropped in the study patients after 8 weeks (p < 0.03); diastolic blood pressure remained unchanged. Estradiol levels were 67 +/- 36 pg/ml at 4 weeks and 70 +/- 49 pg/ml at 8 weeks in the study group. Basal values of peak early and peak atrial velocities, acceleration time and rate, deceleration time and rate, early/atrial velocity ratio and pressure half-time were not significantly different between the estradiol and placebo groups. Doppler values remained unchanged after both 4 and 8 weeks in women receiving estradiol. Women with relatively high serum 17 beta-estradiol levels (> 100 pg/ml) at 4 or 8 weeks of treatment did not present more pronounced changes in the Doppler-derived parameters compared with patients with low hormone levels.

CONCLUSION

The results showed a lack of short-term effects of transdermal estradiol on left ventricular diastolic function in postmenopausal women, irrespective of serum estradiol levels.

Effect of estrogen replacement therapy on cardiac function in postmenopausal women with and without flushes

Left ventricular heart function and its response to long-term estrogen replacement therapy was assessed in 30 postmenopausal women, 20 of whom had modest to severe hot flushes and 10 of whom had never had them. Continuous transdermal estradiol was given to women who had surgically induced menopause, and a combination of transdermal estradiol and sequential medroxyprogesterone acetate was given to those who had spontaneous menopause. Left ventricular systolic and diastolic function was evaluated by complete two-dimensional M-mode and pulsed Doppler echocardiography before and after 6 and 12 months of therapy. The parameters assessed were: systolic and diastolic blood pressure, heart rate, cardiac septal and posterior wall dimensions, left ventricular end-systolic and end-diastolic dimensions and volumes, ejection fraction (EF), ejection time, peak left ventricular outflow velocity (PFV), flow velocity integral (FVI), acceleration time (AT), mean acceleration of systolic flow (MA), duration of early and late filling phase, peak velocity of the early (E) and late (A) mitral flow, and A/E velocity ratio. Although no difference in chamber and wall dimensions between flushers and non-flushers was found, women with hot flushes had lower (not significantly) EF, PFV, FVI, MA, blood pressure and heart rate before therapy. Twelve-month estrogen replacement therapy significantly reduced cardiac wall dimensions and improved systolic function in both flushers and non-flushers. However, stroke volume, EF and MA were increased whereas systolic blood pressure and heart rate were decreased more in flushers. Also, the increase in E mitral flow and decrease in A/E were more pronounced in flushers. Thus, although estrogen replacement therapy significantly improves heart function in healthy postmenopausal women, there appears to be some minor differences in response between flushers and non-flushers.