Effects of acute administration of transdermal estrogen on postmenopausal women with systemic hypertension

Anti-Menopausal Effect of Soybean Germ Extract and Lactobacillus gasseri in the Ovariectomized Rat Model

Menopause is a significant phase in a woman's life. Menopausal symptoms can affect overall well-being and quality of life. Conventionally, hormone replacement therapy (HRT) is used to alleviate menopausal symptoms; however, depending on the conditions, HRT may lead to side effects, necessitating the exploration of alternative therapies with fewer side effects. In this study, we investigated the effects of a combination of soybean germ extract (S30) containing 30% (w/w) isoflavone and a probiotic, Lactobacillus gasseri (LGA1), on menopausal conditions in an ovariectomized (OVX) rat model. We evaluated the impact of S30+LGA on body weight, estrogen markers, uterine and bone health, vascular markers, and neurotransmitter levels. The results revealed that treatment with S30+LGA1 significantly improved body weight and uterine and bone health. Moreover, S30+LGA1 demonstrated promising effects on lipid profile, liver function, and vascular markers and positively impacted serotonin and norepinephrine levels, indicating potential mood-enhancing effects. In conclusion, S30+LGA1, possessing anti-menopausal effects in vitro and in vivo, can be recommended as a soy-based diet, which offers various health benefits, especially for menopausal women.

Estrogen-mediated mechanisms in hypertension and other cardiovascular diseases

Cardiovascular disease (CVD) is the leading cause of death globally for men and women. Premenopausal women have a lower incidence of hypertension and other cardiovascular events than men of the same age, but diminished sex differences after menopause implicates 17-beta-estradiol (E2) as a protective agent. The cardioprotective effects of E2 are mediated by nuclear estrogen receptors (ERα and ERβ) and a G protein-coupled estrogen receptor (GPER). This review summarizes both established as well as emerging estrogen-mediated mechanisms that underlie sex differences in the vasculature during hypertension and CVD. In addition, remaining knowledge gaps inherent in the association of sex differences and E2 are identified, which may guide future clinical trials and experimental studies in this field.

Effects of menopausal hormone therapy on ambulatory blood pressure and arterial stiffness in postmenopausal Korean women with grade 1 hypertension: a randomized, placebo-controlled trial

Background

Estrogen therapy in early menopausal women decreases the risk of coronary heart disease and parenteral, but not oral, estrogen is reported to reduce blood pressure (BP). Progestogens are typically added to estrogens to prevent unopposed endometrial stimulation. The effects of progestogen on BP have been less well studied to date. This study was conducted to explore the impacts of micronized progesterone (MP4) combined with percutaneous estradiol gel (PEG) on hemodynamics in postmenopausal Korean women with grade 1 hypertension.

Methods

Fifty-two postmenopausal women (aged 49–75 years) with systolic BP (SBP) of 140–160 mmHg or diastolic BP (DBP) of 90–100 mmHg were randomly assigned for 12 weeks to placebo (n = 16), estrogen therapy (ET) (n = 19) with PEG (0.1 %, 1 g./d), or estrogen + progestogen therapy (EPT, n = 17) with PEG and MP4 (100 mg/d). The primary endpoint was ambulatory BP and the secondary endpoints were arterial stiffness as brachial–ankle pulse-wave velocity (baPWV) and aortic parameters on applanation tonometry.

Results

One woman in the ET group dropped out, so 51 participants were finally analyzed. Outcome measures for ambulatory BP and arterial stiffness were not different between groups. Within-group comparisons showed that EPT significantly decreased daytime heart rate and baPWV: the changes from baseline (mean ± standard deviation) were − 2.5 ± 5.7 bpm (P = 0.03) and − 0.6 ± 1.4 m/s (P = 0.04), respectively. After adjusting for baseline, linear regression analysis revealed a significant difference in the relationship between baseline and 12-week baPWV among groups (P = 0.02). The relationship was significantly different between placebo and ET (P = 0.03) and EPT (P = 0.01), respectively, but not between ET and EPT. Additionally, pooled results of active treatments disclosed that SBP, DBP, PWV, and augmentation index at the aorta were significantly reduced relative to baseline.

Conclusions

There was no difference in ambulatory BP between ET and EPT in postmenopausal Korean women with grade 1 hypertension. Further, ET and EPT similarly decreased baPWV from baseline as compared with placebo. MP4 might not adversely influence estrogen effects on ambulatory BP and arterial stiffness.

Trial registration

Clinical Research Information Registry, KCT0005405, Registered 22 September 2020 - Retrospectively registered, https://cris.nih.go.kr/cris/search/detailSearch.do?all_type=Y&search_page=L&pageSize=10&page=1&seq=17608&search_lang=E.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40885-021-00175-1.

Isolated systolic hypertension in Asia

Isolated systolic hypertension (ISH) is the most common type of essential hypertension in the elderly and young adults. With rapid industrialization and population aging, the prevalence of ISH in Asia will rise substantially. Asian populations have distinct epidemiological features, risk factors and are especially vulnerable to ISH. There is a pressing need for Asian countries to formulate their unique strategies for control of ISH. In this review, we focus on the (1) epidemiology and pathophysiology, (2) risk factors and impact on outcomes, and (3) treatment goal and strategy for ISH in Asia.

The effect of different estradiol levels on carotid artery distensibility during a long agonist IVF protocol

BACKGROUND

This study was made to figure out, does low and high estradiol levels during in vitro fertilization (IVF) cycles have a different effect on carotid artery distensibility (Cdis), carotid artery diameter (Cdia), blood pressure and metabolic factors? Can the stimulation protocol be considered safe to women's vasculature?

METHODS

We studied 28 women having a long agonist protocol IVF-treatment in Kuopio University Hospital during the years 2011-2016. Patients were examined at three time points: in the beginning of their own period (low estradiol), during the gonadotrophin releasing hormone (GnRH) analogue downregulation (low estradiol) and during the follicle stimulating hormone (FSH) stimulation (high estradiol). Women served as their own controls and their menstrual phase (2- to 5-day period after the beginning of menstruation with low estrogen) was used as the reference. Cdis and Cdia were assessed using ultrasound. Blood pressure, weight, estradiol levels and lipids were monitored.

RESULTS

Cdis, Cdia, systolic and diastolic blood pressures peaked during the GnRH-analogue treatment with the lowest estradiol levels. Cdis, Cdia and systolic blood pressures declined by 11% (P = 0.002), 3,8% (P < 0.001) and 2,5% (P = 0.026) during the FSH-stimulation when the estradiol levels were high. Cdis correlated significantly (P < 0.05) with systolic blood pressure, diastolic blood pressure and triglycerides in high estrogenic environment and with diastolic blood pressure (P < 0.05) when estrogen profiles were low.

CONCLUSIONS

Carotid artery stiffens during the high estradiol levels compared to low levels and this was not explained by the higher diameter of the carotid artery, hyperlipidemia or blood pressure profiles. All the changes in Cdis and Cdia are variations of normal, and if there is no history of cardiovascular problems, it can be considered, that the stimulation protocol is not hazardous to vasculature.

The different role of sex hormones on female cardiovascular physiology and function: not only oestrogens

Human response to different physiologic stimuli and cardiovascular (CV) adaptation to various pathologies seem to be gender specific. Sex-steroid hormones have been postulated as the major contributors towards these sex-related differences. This review will discuss current evidence on gender differences in CV function and remodelling, and will present the different role of the principal sex-steroid hormones on female heart. Starting from a review of sex hormones synthesis, receptors and CV signalling, we will summarize the current knowledge concerning the role of sex hormones on the regulation of our daily activities throughout the life, via the modulation of autonomic nervous system, excitation-contraction coupling pathway and ion channels activity. Many unresolved questions remain even if oestrogen effects on myocardial remodelling and function have been extensively studied. So this work will focus attention also on the controversial and complex relationship existing between androgens, progesterone and female heart.

Hormone replacement therapy and arterial blood pressure in postmenopausal women with hypertension

BACKGROUND

Data on the effect of hormone replacement therapy (HRT) on blood pressure (BP) in hypertensive menopausal women are limited.

OBJECTIVE

To investigate the association between HRT and longitudinal change in BP in hypertensive menopausal women.

PATIENTS AND METHODS

We recruited a total of 161 hypertensive menopausal women (mean age = 52.2 +/- 6.6 years) attending the hypertension clinic in our hospital that requires HRT to attenuate the effect of menopause symptoms. These women were followed for up tp 36 months, being evaluated every 6 months with measurements of their BP, weight and the number of drugs needed to control their BP. We also measured serum cholesterol levels before and after the initiation of HRT.

RESULTS

The systolic BP remained unaffected throughout the whole follow-up period, whereas the diastolic BP was slightly reduced at 6, 24 and 36 months. This decrease was accompanied by an increased need for antihypertensive medication throughout the entire follow-up period, while the body weight also increased at 18, 24, and 36 months. No particular differences were noted with respect to ethnicity, history of pre-eclampsia or surgical menopause, before and after the initiation of HRT. Serum cholesterol levels remained unchanged during the evaluation period. Oestrogen-progestogen combination therapy use was associated with a lower diastolic BP and a smaller number of antihypertensive drugs compared to other forms of HRT.

CONCLUSION

HRT use does not have an adverse gross effect on BP in hypertensive menopausal women who need it, although there may be an increased need for antihypertensive therapy during the 36-moth follow-up period of our study.

The long-term effects of low-dose 17β-estradiol and dydrogesterone hormone replacement therapy on 24-h ambulatory blood pressure in hypertensive postmenopausal women: a 1-year randomized, prospective study

OBJECTIVE

The aim of this study was to assess the long-term effects of low-dose oral hormone replacement therapy (HRT) on 24-h blood pressure in hypertensive postmenopausal women.

STUDY DESIGN

In this 12-month, prospective study, 66 postmenopausal women with mild or moderate hypertension were randomly assigned to receive either HRT with 1 mg/day micronized 17beta-estradiol sequentially combined with 10 mg/day dydrogesterone for 14 days of each 28-day cycle, or no therapy. Ambulatory blood pressure measurements were recorded for a 24-h period at baseline and after 12 months of treatment or follow-up.

RESULTS

Blood pressure did not differ significantly between the groups at baseline. After 12 months, there were falls in 24-h systolic, diastolic and mean arterial blood pressure in both the HRT and control groups; only the fall in mean arterial blood pressure in the HRT group achieved statistical significance (-2.0 +/- 0.8 mmHg, p < 0.01). While there was no significant decrease in daytime systolic or mean arterial blood pressure in either group, a significant decrease in diastolic blood pressure (-1.8 +/- 10 mmHg, p < 0.001) was observed in the HRT group. Night-time systolic and mean arterial blood pressure also decreased significantly (p < 0.001) in the HRT group (-3.0 +/- 1.5 mmHg and -2.2 +/- 0.6 mmHg, respectively), but no significant change was observed in the control group.

CONCLUSION

Low-dose oral HRT caused significant falls in both daytime and night-time ambulatory blood pressure in postmenopausal women with mild or moderate hypertension.

Increased blood pressure in mice lacking cytochrome P450 2J5

The cytochrome P450 (CYP) enzymes participate in a wide range of biochemical functions, including metabolism of arachidonic acid and steroid hormones. Mouse CYP2J5 is abundant in the kidney where its products, the cis-epoxyeicosatrienoic acids (EETs), modulate sodium transport and vascular tone. To define the physiological role of CYP2J5 in the kidney, knockout mice were generated using a conventional gene targeting approach. Cyp2j5 (-/-) mice develop normally and exhibit no overt renal pathology. While renal EET biosynthesis was apparently unaffected by the absence of CYP2J5, deficiency of this CYP in female mice was associated with increased blood pressure, enhanced proximal tubular transport rates, and exaggerated afferent arteriolar responses to angiotensin II and endothelin I. Interestingly, plasma 17beta-estradiol levels were reduced in female Cyp2j5 (-/-) mice and estrogen replacement restored blood pressure and vascular responsiveness to normal levels. There was no evidence of enhanced estrogen metabolism, or altered expression or activities of steroidogenic enzymes in female Cyp2j5 (-/-) mice, but their plasma levels of luteinizing hormone and follicle stimulating hormone were inappropriately low. Together, our findings illustrate a sex-specific role for CYP2J5 in regulation of blood pressure, proximal tubular transport, and afferent arteriolar responsiveness via an estrogen-dependent mechanism.

Chronic estrogen treatment reduces vaso-constrictor responses in insulin resistant rats

Previous experiments have shown that chronic estrogen treatment via subcutaneous implants prevented insulin-induced blood pressure elevation and increased insulin sensitivity in ovariectomized female rats. In vitro vascular studies were performed using isolated mesenteric arteries to determine the effect of chronic estrogen and insulin treatments on vascular responses to vasoconstrictor agents. Female Wistar rats were assigned to the following groups: sham-operated, sham-operated plus insulin, sham-operated plus insulin plus estrogen, ovariectomized, ovariectomized plus insulin, and ovariectomized plus insulin plus estrogen. Chronic insulin and estrogen treatments were initiated with subcutaneous placement of insulin implants (2 U/d) and 17β-estradiol implants (0.5 mg/pellet, 60 day release) at the back of the neck. After 8 weeks of treatment, mesenteric arteries were isolated for assessment of constrictor responses to norepinephrine and the thromboxane A2 analogue U46619 in the presence or absence of the endothelium. The results show that chronic estrogen treatment attenuated the vascular constrictor responses to norepinephrine and U46619 only in endothelium intact vessels. Incubation with insulin did not significantly affect norepinephrine-induced vascular smooth muscle contraction. The study provides evidence that the mechanism by which estrogen prevents insulin-induced blood pressure elevation in insulin-treated ovariectomized rats is by influencing endothelium-derived vasoactive factors such as thromboxane A2.

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.

Influence of methyltestosterone postmenopausal therapy on plasma lipids, inflammatory factors, glucose metabolism and visceral fat: a randomized study

BACKGROUND

There has been a growing interest in treating postmenopausal women with androgens. However, hyperandrogenemia in females has been associated with increased risk of cardiovascular disease.

OBJECTIVE

We aimed to assess the effects of androgen replacement on cardiovascular risk factors.

DESIGN

Thirty-seven postmenopausal women aged 42-62 years that had undergone hysterectomy were prospectively enrolled in a double-blind protocol to receive, for 12 months, percutaneous estradiol (E2) (1 mg/day) combined with either methyltestosterone (MT) (1.25 mg/day) or placebo.

METHODS

Along with treatment, we evaluated serum E2, testosterone, sex hormone-binding globulin (SHBG), free androgen index, lipids, fibrinogen, and C-reactive protein; glucose tolerance; insulin resistance; blood pressure; body-mass index; and visceral and subcutaneous abdominal fat mass as assessed by computed tomography.

RESULTS

A significant reduction in SHBG (P < 0.001) and increase in free testosterone index (P < 0.05; Repeated measures analysis of variance) were seen in the MT group. Total cholesterol, triglycerides, fibrinogen, and systolic and diastolic blood pressure were significantly lowered to a similar extent by both regimens, but high-density lipoprotein cholesterol decreased only in the androgen group. MT-treated women showed a modest rise in body weight and gained visceral fat mass relative to the other group (P < 0.05), but there were no significant detrimental effects on fasting insulin levels and insulin resistance.

CONCLUSION

This study suggests that the combination of low-dose oral MT and percutaneous E2, for 1 year, does not result in expressive increase of cardiovascular risk factors. This regimen can be recommended for symptomatic postmenopausal women, although it seems prudent to perform baseline and follow-up lipid profile and assessment of body composition, especially in those at high risk of cardiovascular disease.

Effects of Candesartan for Middle-Aged and Elderly Women with Hypertension and Menopausal-Like Symptoms

Hypertension in middle-aged or elderly women is often accompanied with various symptoms, which may be related to climacteric. The symptoms of post-menopausal women are suggested to be derived in part from instability of the sympathetic nerve system due to a low estrogen state. An angiotensin-receptor blocker, candesartan cilexetil (candesartan), is known to suppress sympathetic nerve activity by inhibiting the renin-angiotensin system in the brain, suggesting that it may be effective for ameliorating these symptoms. The aim of this study was to elucidate whether candesartan improves menopausal symptoms in hypertensive women. A total of 69 female patients, aged 40 years or older, who had hypertension and various menopausal-like symptoms, were recruited from 39 centers to participate in this study. Patients were prescribed candesartan 4 to 8 mg/day (average dose 7.2 mg/day), alone or in addition to current antihypertensive medications. We interviewed patients in regard to their menopausal symptoms and scored them using the Simplified Menopausal Index (SMI). During the 12-month observation period, significant decreases were seen in both blood pressure (157+/-21/85+/-11 to 141+/-18/77+/-12 mmHg, p<0.001) and SMI (29+/-18 to 18+/-7, p<0.001), although the heart rate did not change. The percentage of decrease in SMI was correlated with that in systolic blood pressure (r=0.43, p<0.001). Candesartan may be an effective antihypertensive agent to relieve menopausal-like symptoms in middle-aged or elderly hypertensive women.

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.

Menopause induced by oophorectomy reveals a role of ovarian estrogen on the maintenance of pressure homeostasis

OBJECTIVES

Following spontaneous menopause women show a greater increase in systolic and diastolic blood pressure than men of the same age. The aim of the present study was to assess the effect of acute ovarian hormone withdrawal and replacement on blood pressure and forearm blood flow.

METHODS

We studied 18 fertile middle-aged normotensive women (48 +/- 1.5 years, range 46-51 years) 1 week prior and 1 month subsequent to bilateral oophorectomy by means of 24-h blood pressure monitoring and strain-gauge venous occlusion plethysmography. Eighteen subjects who had undergone hysterectomy with ovarian sparing, matched for age and biophysical characteristics, were used as a control group. All women were free from cardiovascular risk factors or disease.

RESULTS

Oophorectomy increased the mean values of 24 h (P < 0.001), daytime (P < 0.05), and nighttime (P < 0.01) diastolic blood pressure and nighttime systolic blood pressure (P < 0.01). Blood pressure increase was associated with a rise in forearm vascular resistance (P < 0.01). No significant changes in either blood pressure or forearm vascular resistance values were observed in hysterectomized women. In 16 oophorectomized women a 3-month estrogen replacement therapy (ERT) (17beta-estradiol, 100 mcg/day by transdermal patches) brought blood pressure and forearm vascular resistance values to a level comparable to that recorded before intervention.

CONCLUSIONS

Surgically-induced menopause causes an increase in peripheral vascular resistance and blood pressure suggesting a role of ovarian hormones in the homeostatic pressure modulation. Recovery of the baseline condition after ERT suggests that the accelerated increase in blood pressure after menopause is due to ovarian and above all estrogen insufficiency.

Effects of hormone replacement therapy on office and ambulatory blood pressure in Japanese hypertensive postmenopausal women

No study has demonstrated that hormone replacement therapy (HRT) affects blood pressure (BP) measured by 24-h ambulatory blood pressure monitoring (ABPM) in Japanese postmenopausal women (PMW) with normotension or mild-to-moderate essential hypertension. In the present study, we examined the effects of HRT on office BP and 24-h ambulatory blood pressure (ABP) in Japanese hypertensive or normotensive PMW. Thirty-one hypertensive (HT-HRT group) and 17 normotensive PMW (NT-HRT group) received HRT (0.625 mg of conjugated equine estrogen combined with 2.5 mg of medroxyprogesterone acetate) orally for 12 months, and 30 hypertensive (HT-Control group) and 19 normotensive PMW (NT-Control group) did not receive HRT. In all of the hypertensive PMW, BP was controlled by a variety of antihypertensive drugs before starting HRT. The hypertensive PMW were divided into two groups according to the results of ABP before HRT: nondippers (those without a diurnal change in BP) and dippers (those with a diurnal change in BP). In all patients, office BP measurements and 24-h ABPM were performed before and 12 months after the start of HRT. HRT did not change either the office or the 24-h ambulatory systolic, diastolic, or mean BP in any of the groups. Therefore, HRT did not significantly alter the proportion of nondippers. We conclude that with respect to BP, HRT might not be harmful in hypertensive PMW whose BP has been well-controlled prior to the initiation of HRT, as well as in normotensive PMW.

Hormone therapy and the cardiovascular system

The cardiovascular effects of female sex steroids have many faces and are very complex. To make this situation even more complicated different disease situations, different target organs and different therapeutic regimens may exhibit different effects of estrogens and progestines. Furthermore, the interpretation of population studies may be problematic by itself, in view of so many confounders and biases involved and methodological flaws that sometimes are discovered only post-hoc. It seems, therefore, that in such a complicated situation making definite conclusions and guidelines is almost an impossible task. My suggestion to clinicians is to try and follow the main stream of clinical data, looking at the general picture rather than the small details, and try to individualize therapy in order to maximize the benefits and minimize the adverse reactions and risks. This article discusses the current knowledge on hormone replacement therapy (HRT) and the cardiovascular system. It is not an overview, because my intention was not to pump in as much data as possible. Rather, the article presents current ideas and trends in this field to be used by people who practice menopause medicine for their own clinical decisions.

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.

Menopause and the characteristics of the large arteries in a population study

In previous cross-sectional and longitudinal population studies, we found that the slope of systolic pressure on age was steeper in postmenopausal than in premenopausal women. We hypothesised that this observation could be due to a specific effect of menopause on the elasticity of the large arteries. We investigated 315 randomly selected women, aged 30 to 70 years. Based on 5.2 years of follow-up, 166 women were premenopausal and 149 menopausal (44 reaching menopause and 105 postmenopausal). These women were matched on age and body mass index with 315 men. We used a wall-tracking ultrasound system to measure the diameter, compliance and distensibility of the brachial and the common carotid and femoral arteries as well as carotid-femoral pulse wave velocity. Pulse pressure was determined from 24-h blood pressure recordings. Both in menopausal women (r = 0.37; P < 0.001) and in matching male controls (r = 0.16; P = 0.04), pulse pressure widened with increasing age. The slope of the 24-h pulse pressure on age was steeper in menopausal women than in their premenopausal counterparts (0.428 vs -0.066 mm Hg per year; P = 0.003) and than in the male controls (0.428 vs 0.188 mm Hg per year; P = 0.06). After adjustment for age, 24-h mean pressure, body mass index, antihypertensive drug treatment, smoking and the use of oral contraceptives or hormonal replacement therapy, postmenopausal women showed a higher carotid-femoral pulse wave velocity (7.77 vs 6.71 m/s; P = 0.02) and had a slightly greater diameter of the common carotid artery (7.09 vs 6.79 mm; P = 0.07) than their premenopausal counterparts. After similar adjustments, menopausal class was not significantly associated with other vascular measurements in women or with any vascular measurement in control men. In conclusion, menopause per se may increase aortic stiffness. We hypothesise that this phenomenon may contribute to the rise in systolic pressure and pulse pressure in women beyond age 50 and, in turn, may lead to a slight dilatation of the common carotid artery.

Influence of ovariectomy on ventricular myocyte contraction in simulated diabetes

We studied the effect of ovariectomy (OVX) on cardiac contraction in myocytes maintained under a 'diabetes-simulated high-glucose' environment. Female rats were ovariectomized or sham operated (SHAM) and kept for 6 weeks. Isolated myocytes were maintained in a diabetes-simulated high [glucose] medium (HG; 25.5 mM) for 24 h before mechanical properties were measured. Contractile indices analyzed included peak shortening (PS), time to PS (TPS), time to 90% relengthening (TR90), maximal velocity of shortening and relengthening (+/- dL/dt), intracellular Ca2+ fura-2 fluorescence intensity and decay rate (tau). Nitric oxide synthase (NOS) activity was also evaluated. OVX myocytes displayed a longer TR(90), slower +/- dL/dt, lower fluorescence intensity and higher tau (slower decay rate) when compared to SHAM myocytes. In the SHAM group, HG exerted diabetes-like contractile dysfunctions, including depressed PS, prolonged TR90, reduced fluorescence intensity, higher tau and enhanced NOS activity when compared to myocytes maintained in low [glucose] medium (5.5 mM). Interestingly, the HG- induced mechanical alterations were significantly exaggerated (TPS, TR90 and tau), reversed (PS and NOS) or lost (+/- dL/dt and fluorescence intensity) in the OVX group. These data suggest that ovarian hormones play a role in the regulation of cardiac contractile function, and may have potentially protective effects against diabetes-associated cardiac dysfunction.

Hormone replacement therapy and hypertension

For many years, Hormone Replacement Therapy (HRT) was considered to be contraindicated in postmenopausal women with hypertension and many such women were excluded from HRT because of concerns that HRT may have an adverse effect on blood pressure. This perception was mainly due to the effects of oral contraceptive drugs, especially the oestrogen component, in increasing blood pressure. Differences exist between the formulation and doses of oestrogen preparations used, either as oral contraceptives in premenopausal women (in whom high-dose synthetic oestrogens are used) or as HRT in postmenopausal women (in whom low "replacement" doses of natural oestrogens are used). This is not inconsequential, as postmenopausal women represent the largest category of women at risk for hypertension. The aim of this review is to give a balanced view on the effects of HRT on blood pressure in postmenopausal women.

17beta-estradiol prevents oxidative stress and decreases blood pressure in ovariectomized rats

In this study, we tested whether estrogen deficiency is associated with oxidative stress and decreased nitric oxide (NO) production, which could be responsible for an increased blood pressure in ovariectomized rats. Hemodynamic studies were performed on conscious, chronically instrumented rats. Chronic estrogen replacement on ovariectomized rats lowered blood pressure approximately 13 mmHg, from 119 +/- 3 mmHg in ovariectomized rats to 106 +/- 3 mmHg in ovariectomized-treated rats; it was also accompanied by an increase in cardiac index and vascular conductance, achieving hemodynamic values similar to those shown by sham-operated rats. N(G)-nitro-L-arginine methyl ester administration lowered significantly less the vascular conductance (0.14 +/- 0.01 vs. 0.22 +/- 0.03 and 0.26 +/- 0.01 ml. min(-1). mmHg(-1)/100 g; P < 0.05) in ovariectomized rats than in the sham-operated and estrogen-treated ovariectomized rats, respectively. Estrogen replacement prevented the lower plasma levels of nitrites/nitrates observed in ovariectomized rats. The lower plasma total antioxidant status and reduced thiol groups and the increase in plasma lipoperoxides presented in ovariectomized animals were reestablished with the estrogen treatment. These results show that estrogen administration decreases blood pressure and increases vascular conductance in ovariectomized rats. This effect may be related to an increase in NO synthesis and/or preventing oxidative stress, then improving endothelial function.

Inability to induce hypertension in normotensive rat expressing AT(1) receptor antisense

Our previous studies have shown that neonatal delivery of angiotensin type 1 receptor antisense (AT(1)R-AS) in a retroviral vector prevents spontaneously hypertensive rats from developing hypertension for life but has no effect on blood pressure (BP) in normotensive animals. Based on these results, we hypothesized that AT(1)R-AS transduction in normotensive rats would protect them from developing experimental hypertension. The present study was designed to evaluate this hypothesis. A single intracardiac administration of AT(1)R-AS by a retroviral-mediated delivery system (LNSV-AT(1)R-AS) in 5-day-old normotensive Sprague-Dawley rats resulted in long-term expression of the AT(1)R-AS without an effect on basal BP. However, angiotensin II (Ang II)-induced BP, dipsogenic responses, and renovascular contractility were significantly attenuated in the LNSV-AT(1)R-AS-treated rats. Chronic infusion of low-dose Ang II (55 ng. kg(-)(1). min(-)(1)) in LNSV-alone-treated rats caused a modest increase in BP, profound increase in cardiac hypertrophy, and increased vascular contractility. In contrast, the LNSV-AT(1)R-AS-treated rats were protected from developing these changes after Ang II infusion. These data establish that LNSV-AT(1)R-AS pretreatment protects healthy rats from developing Ang II-dependent hypertension.

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

To reduce cardiovascular complications, antihypertensive therapy should not only normalize blood pressure but also induce a regression of structural abnormalities, which are the expression of end-organ damage. We investigated the effects of transdermal 17beta-estradiol, combined with standard antihypertensive therapy, on the modification of left ventricular anatomy and systolic performance in hypertensive postmenopausal women. In a randomized, double-blind, placebo-controlled study, we enrolled 169 postmenopausal women with mild or moderate hypertension. Eighty-six patients (group 1) received transdermal 17beta-estradiol (50 microg/d) and norethisterone acetate (2.5 mg/d, orally), and 83 patients (group 2) received placebo. At baseline, all women underwent M-mode and 2-D echocardiogram, which was repeated after 6, 12, and 18 months of follow-up. After 18 months of treatment, we observed a significant decrease in left ventricular diastolic septal and posterior wall thickness and mass in both groups. Furthermore, after 18 months, left ventricular mass was significantly less than in the estrogen-treated group. No significant modifications were observed in left ventricular systolic and diastolic dimensions or in systolic performance, as expressed by left ventricular fractional shortening. In conclusion, transdermal 17beta-estradiol, which is associated with antihypertensive therapy, may contribute in the reduction of left ventricular mass in hypertensive postmenopausal women.

Study of myocardial contractility by pulsed wave Doppler tissue imaging does not reveal an inotropic effect of estrogen at physiologic dose

We studied myocardial contractility by pulsed wave Doppler tissue imaging in 6 postmenopausal healthy women. According to a crossover, double-blind protocol, we randomized patients to treatment with transdermal patches of estradiol-17beta or matched placebo. Estradiol-17beta did not modify local systolic and diastolic functions. Thus, at least when acutely administered, estrogen seems to be unable to determine hemodynamic changes at the myocardial level, in opposition to what occurs in the peripheral vascular system.

Estradiol with or without progesterone and ambulatory blood pressure in postmenopausal women

The purpose of this study was to determine whether transdermal estradiol and intravaginal progesterone given in doses to mimic the premenopausal state would lower blood pressure (BP) in postmenopausal women. Fifteen healthy postmenopausal women were studied in each of 3 conditions: on placebo, after 8 weeks of transdermal estradiol 0.2 mg twice per week, and again 2 weeks after addition of intravaginal progesterone 300 mg/d. Women were studied at each point after 2 days of 100 mmol/d sodium intake. Twenty-four-hour ambulatory BP monitoring was performed, and blood was assayed for estradiol, progesterone, and hormones of the renin-angiotensin-aldosterone system (RAAS). ANOVA with pairwise comparisons was used for analysis. Urinary sodium excretion was similar at each time point. Levels of estrogen and progesterone similar to those in premenopausal women were achieved. On estradiol, nocturnal systolic BP (110+/-3 mm Hg), diastolic BP (63+/-2 mm Hg), and mean BP (77+/-2 mm Hg) fell significantly (P<0.02) compared with placebo systolic BP (116+/-2 mm Hg), diastolic BP (68+/-2 mm Hg), and mean BP (82+/-2 mm Hg). Daytime BP followed the same trend but was significantly lower only for mean BP. There was no activation of the RAAS. The addition of progesterone resulted in no further fall in BP but a significant activation of the RAAS. Thus, contrary to what is often assumed, administration of estradiol with or without progesterone not only did not raise BP but rather substantially lowered BP. This BP-lowering effect may be responsible for the lower incidence of hypertension in premenopausal than in postmenopausal women.

Impaired forearm blood flow and vasodilator reserve in healthy postmenopausal women

BACKGROUND

The natural process of cessation of ovarian estrogen production is associated with an increasing incidence of cardiovascular disease.

OBJECTIVE

We aimed to determine whether postmenopausal women had menopause-associated vasomotor disturbances develop.

METHODS

We studied the vascular forearm function using strain-gauge venous occlusion plethysmography in 12 healthy postmenopausal women (mean age +/- SD, 47 +/- 3 years; time-lapse from menopause >1 year). Twelve premenopausal subjects matched for age and biophysical characteristics were used as a control group.

RESULTS

No differences were observed in heart rate or mean blood pressure between the 2 groups of women. Forearm blood flow at supine resting was lower in postmenopausal than in premenopausal women (2.4 +/- 0.8 vs 3.1 +/- 0.5 mL/100 mL/min; P <.05). Local vascular resistance was higher in postmenopausal than in premenopausal women (43.5 +/- 17.5 vs 31.1 +/- 4.3 mm Hg/mL/100 mL/min; P <.05). Moreover, peak forearm flow in response to forearm ischemia was 20.8 +/- 7.9 mL/100 mL/min in postmenopausal women and 26.6 +/- 9.7 mL/100 mL/min in premenopausal women (P <.01). Plasma concentration of noradrenaline in the supine position was significantly higher in postmenopausal than in premenopausal women (286 +/- 22 pg/mL vs 195 +/- 33 pg/mL; P <.01). Finally, a significant positive relation was revealed in postmenopausal women between the amount of vasodilator reserve (D flow) in local peripheral circulation and levels of circulating estradiol-17beta.

CONCLUSIONS

Abnormalities observed in forearm blood flow and vasodilator capacity in postmenopausal women may be attributed to a critical loss of the vasodilating property of physiologic estrogen. Our data support the possibility that reduction in dilator capacity of the vasculature may contribute to the increase of cardiovascular disease after menopause.

Physiological doses of estradiol decrease nocturnal blood pressure in normotensive postmenopausal women

The effect of a 2-mo treatment with transdermal estradiol (50 microgram/day) versus placebo on 24 h of blood pressure rhythm was investigated in 18 normotensive healthy postmenopausal women. Whereas daytime blood pressure was not modified, nighttime blood pressure was reduced by estradiol. Estradiol magnified the nocturnal decrement of systolic (14.3 +/- 7.2 vs. 9.8 +/- 6.7 mmHg, P = 0. 0033), diastolic (11.6 +/- 5.0 vs. 7.5 +/- 7.3 mmHg, P = 0.028), and mean (10.8 +/- 5.6 vs. 7.2 +/- 4.5 mmHg, P = 0.011) blood pressure. As a consequence, the 24-h rhythm of mean blood pressure was restored in 50% of the subjects (P = 0.045) in whom it was absent and was amplified in the remaining 50% of the subjects. Body mass index was an independent determinant of blood pressure values being directly related to the amplitude of the 24-h mean blood pressure rhythm (r2 = 0.38; P = 0.0067). In normotensive postmenopausal women, physiological doses of estradiol amplify the nocturnal decline of blood pressure.

Effects of 17beta-estradiol on sympathetic activity and pressor response to phenylephrine in ovariectomized rats

The effects of 17beta-estradiol (E2) on sympathetic activity were examined in conscious unrestrained ovariectomized rats, instrumented under methohexital anesthesia to record mean arterial pressure (MABP), heart rate (HR), renal nerve activity (RNA), and splanchnic nerve activity (SNA) 1 day before the experiment. Injection of E2 (150 micrograms/kg iv) caused reductions (P < 0.01) in RNA (29 +/- 6%), SNA (25 +/- 2%), and HR (26 +/- 5 beats/min) within 20 min, but MABP remained unchanged. Ninety minutes after intravenous injection of E2 or vehicle, intravenous infusion of phenylephrine (PE; 6.2 micrograms . min-1 . kg-1) induced similar increases in MABP and decreases in HR, RNA, and SNA in both groups. By contrast, in rats chronically treated with E2, the pressor response to PE was smaller (P < 0.01; 22 +/- 5 mmHg) than in vehicle-treated rats (40 +/- 4 mmHg). The changes in HR, RNA, and SNA were similar in both groups, but the ratios of changes in HR and SNA to MABP, an index of baroreflex sensitivity, were greater in the E2-treated rats. These findings suggest that E2 can act centrally to modulate sympathetic function and thereby participate in cardiovascular regulation.

Hypertension in women: current understanding of gender differences

High blood pressure is a major individual and public-health issue because of its wide prevalence and associated complications. More women than men have hypertension, but until recently, women have been relatively underrepresented in clinical trials. Gender differences in the physiology, genetics, and treatment benefit of hypertension have been noted in several studies that have included women. These findings have raised concerns about the generalizability of the results of previous investigations to women. The currently available information regarding gender differences and similarities and the results of hypertension treatment trials in women are reviewed herein. These studies suggest that, although gender differences exist, women benefit significantly when they receive therapy to normalize blood pressure.