Effect of hormone replacement therapy on carotid arterial compliance in healthy postmenopausal women

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.

Relation of Sex Hormone Levels With Prevalent and 10-Year Change in Aortic Distensibility Assessed by MRI: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Women experience a steeper decline in aortic elasticity related to aging compared to men. We examined whether sex hormone levels were associated with ascending aortic distensibility (AAD) in the Multi-Ethnic Study of Atherosclerosis.

METHODS

We studied 1,345 postmenopausal women and 1,532 men aged 45-84 years, who had serum sex hormone levels, AAD measured by phase-contrast cardiac magnetic resonance imaging, and ejection fraction>50% at baseline. Among these participants, 457 women and 548 men returned for follow-up magnetic resonance imaging 10-years later. Stratified by sex, and using mixed effects linear regression methods, we examined associations of sex hormones (as tertiles) with baseline and annual change in log-transformed AAD (mm Hg-110-3), adjusting for demographics, body size, lifestyle factors, mean arterial pressure, heart rate, hypertensive medication use (and in women, for hormone therapy use and years since menopause).

RESULTS

The mean (SD) age was 65 (9) for women and 62 (10) years for men. AAD was lower in women than men (P < 0.001). In adjusted cross-sectional analysis, the highest tertile of free testosterone (compared to lowest) in women was significantly associated with lower AAD [-0.10 (-0.19, -0.01)] and the highest tertile of estradiol in men was associated with greater AAD [0.12 (0.04, 0.20)]. There were no associations of sex hormones with change in AAD over 10 years, albeit in a smaller sample size.

CONCLUSIONS

Lower free testosterone in women and higher estradiol in men were associated with greater aortic distensibility at baseline, but not longitudinally. Sex hormone levels may account for differences in AAD between women and men.

Hormone therapy for preventing cardiovascular disease in post-menopausal women

BACKGROUND

Evidence from systematic reviews of observational studies suggests that hormone therapy may have beneficial effects in reducing the incidence of cardiovascular disease events in post-menopausal women, however the results of randomised controlled trials (RCTs) have had mixed results. This is an updated version of a Cochrane review published in 2013.

OBJECTIVES

To assess the effects of hormone therapy for the prevention of cardiovascular disease in post-menopausal women, and whether there are differential effects between use in primary or secondary prevention. Secondary aims were to undertake exploratory analyses to (i) assess the impact of time since menopause that treatment was commenced (≥ 10 years versus < 10 years), and where these data were not available, use age of trial participants at baseline as a proxy (≥ 60 years of age versus < 60 years of age); and (ii) assess the effects of length of time on treatment.

SEARCH METHODS

We searched the following databases on 25 February 2014: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and LILACS. We also searched research and trials registers, and conducted reference checking of relevant studies and related systematic reviews to identify additional studies.

SELECTION CRITERIA

RCTs of women comparing orally administered hormone therapy with placebo or a no treatment control, with a minimum of six months follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for each outcome. We combined results using random effects meta-analyses, and undertook further analyses to assess the effects of treatment as primary or secondary prevention, and whether treatment was commenced more than or less than 10 years after menopause.

MAIN RESULTS

We identified six new trials through this update. Therefore the review includes 19 trials with a total of 40,410 post-menopausal women. On the whole, study quality was good and generally at low risk of bias; the findings are dominated by the three largest trials. We found high quality evidence that hormone therapy in both primary and secondary prevention conferred no protective effects for all-cause mortality, cardiovascular death, non-fatal myocardial infarction, angina, or revascularisation. However, there was an increased risk of stroke in those in the hormone therapy arm for combined primary and secondary prevention (RR 1.24, 95% CI 1.10 to 1.41). Venous thromboembolic events were increased (RR 1.92, 95% CI 1.36 to 2.69), as were pulmonary emboli (RR 1.81, 95% CI 1.32 to 2.48) on hormone therapy relative to placebo.The absolute risk increase for stroke was 6 per 1000 women (number needed to treat for an additional harmful outcome (NNTH) = 165; mean length of follow-up: 4.21 years (range: 2.0 to 7.1)); for venous thromboembolism 8 per 1000 women (NNTH = 118; mean length of follow-up: 5.95 years (range: 1.0 to 7.1)); and for pulmonary embolism 4 per 1000 (NNTH = 242; mean length of follow-up: 3.13 years (range: 1.0 to 7.1)).We performed subgroup analyses according to when treatment was started in relation to the menopause. Those who started hormone therapy less than 10 years after the menopause had lower mortality (RR 0.70, 95% CI 0.52 to 0.95, moderate quality evidence) and coronary heart disease (composite of death from cardiovascular causes and non-fatal myocardial infarction) (RR 0.52, 95% CI 0.29 to 0.96; moderate quality evidence), though they were still at increased risk of venous thromboembolism (RR 1.74, 95% CI 1.11 to 2.73, high quality evidence) compared to placebo or no treatment. There was no strong evidence of effect on risk of stroke in this group. In those who started treatment more than 10 years after the menopause there was high quality evidence that it had little effect on death or coronary heart disease between groups but there was an increased risk of stroke (RR 1.21, 95% CI 1.06 to 1.38, high quality evidence) and venous thromboembolism (RR 1.96, 95% CI 1.37 to 2.80, high quality evidence).

AUTHORS' CONCLUSIONS

Our review findings provide strong evidence that treatment with hormone therapy in post-menopausal women overall, for either primary or secondary prevention of cardiovascular disease events has little if any benefit and causes an increase in the risk of stroke and venous thromboembolic events.

The effect of hormone therapy on mean blood pressure and visit-to-visit blood pressure variability in postmenopausal women: results from the Women's Health Initiative randomized controlled trials

OBJECTIVES

Mean and visit-to-visit variability (VVV) of blood pressure (BP) are associated with an increased cardiovascular disease risk. We examined the effect of hormone therapy on mean and VVV of BP in postmenopausal women from the Women's Health Initiative (WHI) randomized controlled trials.

METHODS

BP was measured at baseline and annually in the two WHI hormone therapy trials, in which 10 739 and 16 608 postmenopausal women were randomized to conjugated equine estrogens (CEEs, 0.625 mg/day) or placebo, and CEEs and medroxyprogesterone acetate (MPA, 2.5 mg/day) or placebo, respectively.

RESULTS

At the first annual visit (year 1), mean SBP was 1.04 mmHg [95% confidence interval (CI) 0.58, 1.50] and 1.35 mmHg (95% CI 0.99, 1.72) higher in the CEEs and CEEs and MPA arms, respectively, compared with the corresponding placebos. These effects remained stable after year 1. CEEs also increased the VVV of SBP (ratio of VVV in CEEs vs. placebo, 1.03; P < 0.001), whereas CEEs and MPA did not (ratio of VVV in CEEs and MPA vs. placebo, 1.01; P = 0.20). After accounting for study drug adherence, the effects of CEEs and CEEs and MPA on mean SBP increased at year 1, and the differences in the CEEs and CEEs and MPA arms vs. placebos also continued to increase after year 1. Further, both CEEs and CEEs and MPA significantly increased the VVV of SBP (ratio of VVV in CEEs vs. placebo, 1.04; P < 0.001; ratio of VVV in CEEs and MPA vs. placebo, 1.05; P < 0.001).

CONCLUSION

Among postmenopausal women, CEEs and CEEs and MPA at conventional doses increased mean and VVV of SBP.

Pharmacological modulation of arterial stiffness

Arterial stiffness has emerged as an important marker of cardiovascular risk in various populations and reflects the cumulative effect of cardiovascular risk factors on large arteries, which in turn is modulated by genetic background. Arterial stiffness is determined by the composition of the arterial wall and the arrangement of these components, and can be studied in humans non-invasively. Age and distending pressure are two major factors influencing large artery stiffness. Change in arterial stiffness with drugs is an important endpoint in clinical trials, although evidence for arterial stiffness as a therapeutic target still needs to be confirmed. Drugs that independently affect arterial stiffness include antihypertensive drugs, mostly blockers of the renin-angiotensin-aldosterone system, hormone replacement therapy and some antidiabetic drugs such as glitazones. While the quest continues for 'de-stiffening drugs', so far only advanced glycation endproduct cross-link breakers have shown promise.

Effect of conjugated estrogen versus conjugated estrogen associated with medroxyprogesterone acetate in postmenopausal women on internal carotid artery pulsatility index: a randomized pilot study

AIM

To compare the effect of conjugated estrogen (CEE) versus conjugated estrogen and medroxyprogesterone acetate (MPA) therapy on internal carotid artery pulsatility index (PI) in postmenopausal women.

MATERIAL & METHODS

In the prospective, randomized, single-blinded comparative study, postmenopausal women meeting the inclusion criteria were randomized into one of two groups: CEE group (CEE 0.625 mg/day), or CEE + MPA group (CEE 0.625 mg/day plus MPA 2.5 mg/day). Patients were submitted to blood tests (total cholesterol, high-density lipoprotein cholesterol, triglycerides and total glucose) and to color Doppler ultrasound of the internal carotid artery to assess PI at the beginning of the study. Ultrasound was repeated after 16 weeks of treatment. Statistical analysis was performed using Student's t-test or two-way analysis of variance for repeated measures. Data were considered to be significant at P < 0.05.

RESULTS

Seventy-five postmenopausal women (age 53.3 ± 5.5 years) were included in the study. There was a statistically significant reduction in PI in both groups after 16 weeks of hormonal treatment. However, there was no difference between the two groups (group 1: 0.8960 to 0.8450; group 2: 0.9048 to 0.8426).

CONCLUSION

The use of CEE and CEE associated with MPA during 16 weeks led to an improvement in internal carotid flow as measured by PI, with no difference between the treatments.

The effect of ovariectomy and estrogen on penetrating brain arterioles and blood-brain barrier permeability

OBJECTIVE

We investigated the effect of estrogen replacement on the structure and function of penetrating brain arterioles (PA) and blood-brain barrier (BBB) permeability.

MATERIALS AND METHODS

Female ovariectomized Sprague-Dawley rats were replaced with estradiol (E(2)) and estriol (E(3)) (OVX + E; N=13) and compared to ovariectomized animals without replacement (OVX; N=14) and intact controls (CTL, proestrous; N=13). Passive and active diameters, percent tone, and passive distensibility of pressurized PA were compared. In addition, BBB permeability to Lucifer Yellow, a marker of transcellular transport, was compared in cerebral arteries.

RESULTS

Ovariectomy increased myogenic tone in PA, compared to CTL, that was not ameliorated by estrogen treatment. Percent tone at 75 mmHg for CTL vs. OVX and OVX + E was 44+/-3% vs. 51+/-1% and 54+/-3% (P<0.01 vs. CTL for both). No differences were found in passive diameters or distensibility between the groups. BBB permeability increased 500% in OVX vs. CTL animals; however, estrogen replacement restored barrier properties: flux of Lucifer Yellow for CTL, OVX, and OVX + E was (ng/mL): 3.4+/-1.2, 20.2+/-5.3 (P<0.01 vs. CTL), and 6.15+/-1.2 (n.s.).

CONCLUSIONS

These results suggest that estrogen replacement may not be beneficial for small-vessel disease in the brain, but may limit BBB disruption and edema under conditions that cause it.

The effect of female hormone manipulation on nasal physiology

BACKGROUND

This study was performed to establish whether the ovarian hormone beta-estradiol has any influence on nasal physiology when manipulated during in vitro fertilization treatment.

METHODS

Women undergoing in vitro fertilization (IVF) treatment at the Assisted Conception Unit, Leicester Royal Infirmary, were recruited. Nasal peak inspiratory flow rate, acoustic rhinometry, anterior rhinomanometry, mucociliary clearance, olfactory thresholds, quality of life, and serum 17-beta-estradiol levels were measured at each visit. Subjects were studied at the beginning of their IVF treatment and then at one or two additional occasions while they received synthetic follicule-stimulating hormone with a final set of results taken at the end of their treatment.

RESULTS

Results were analyzed using paired t-tests. There was no statistical difference between any of the data sets for any of the variables during the process of IVF treatment.

CONCLUSION

Increasing levels of beta-estradiol that occur in IVF treatment cause no significant effect on nasal physiology in contrast to the effects seen during pregnancy.

Functional characterization and sex differences in small mesenteric arteries of the estrogen receptor-β knockout mouse

The role of the estrogen receptor (ER) subtypes in the modulation of vascular function is poorly understood. The aim of this study was to characterize ex vivo the functional properties of small arteries and their response to estrogens in the mesenteric circulation of female and male ER-β knockout mice (β-ERKO) and their wild-type (WT) littermates. Responses to changes in intraluminal flow and pressure were obtained before and after incubation with 17β-estradiol or ER-α agonist propyl-pyrazole-triol (3 h; 10 nM). Cumulative concentration-response curves to acetylcholine, norepinephrine, and passive distensibility were compared with respect to sex and genotype. The collagen and elastin content within the vascular wall and ER expression were also determined. Endothelial morphology was visualized by scanning electron microscopy. 17β-Estradiol and propyl-pyrazole-triol-treated arteries from female β-ERKO and WT mice showed enhanced flow-mediated dilation, but this was not evident in males. Distensibility was decreased in arteries from β-ERKO females. Sex differences in myogenic tone were observed in 17β-estradiol-treated arteries, but were similar between β-ERKO and WT mice. Acetylcholine- and norepinephrine-induced responses were similar between groups and sexes. ER-α was similarly expressed in the endothelium and media of arteries from all groups studied, as well as ER-β in WT animals. Endothelial morphology was similar in arteries from animals of both sexes and genotype; however, arterial elastin content was decreased, and collagen content was increased in β-ERKO male compared with WT male and with β-ERKO female. We suggest that ERs play a sex-specific role in estrogen-mediated flow responses and distensibility, and that deletion of ER-β affects artery structure but only in male animals. Further studies in β-ERKO mice with established hypertension and in α-ERKO mice are warranted.

Vascular and metabolic effects of sex steroids: new insights into clinical trials

The early discontinuation of the Women's Health Initiative trials of daily conjugated estrogens and medroxyprogesterone and of conjugated estrogens only was hailed as the "death to the use of hormone replacement regimens" in menopause. The analyses showed risks outweighing benefits of hormone therapy when given broadly to postmenopausal women. The expanding basic science and clinical research on the specific actions of sex steroids at the genomic and nongenomic level, however, shed new insight into these results. This review focuses on the vascular and metabolic effects of sex steroids to illustrate new advances. Understanding the mechanisms of sex steroid receptor action in a tissue-specific manner, ligand-specific dose responses, and the effects of steroid hormones in normal compared to diseased tissues may explain some of the outcomes in the clinical trials. Further research will clarify the potential benefits and risks of hormone therapy after menopause, both in individual patients and in selected populations.

Does hormone treatment alter arterial properties in postmenopausal women?

Arterial elastic properties and wave reflections constitute left ventricular pulsatile afterload and are directly related to cardiovascular morbidity and mortality. During the aging process, elastic arteries stiffen and increase pulse wave velocity, causing the reflected pressure wave to arrive at the heart during systole, and augment systolic and pulse blood pressure, resulting in left ventricular hypertrophy. The incidence of cardiovascular disease is much greater in men aged 30-50 years compared with women of a similar age. Among women, the incidence of cardiovascular disease increases dramatically after menopause, which occurs at an average age of 52 years. This observation has lead to the belief that sex hormones produced premenopausally impede or delay the progression of cardiovascular disease. Therefore, it appears logical that the administration of female sex hormones, hormone treatment (HT), estrogen alone or with progesterone should provide some degree of cardiovascular protection. This idea was supported by experiments in animals and isolated arterial segments demonstrating that HT increases plasma nitric oxide, decreases endothelin-1 levels and causes smooth muscle relaxation. Also, 17β-estradiol administration decreases collagen and increases elastin in the aortic wall of rats. These experimental studies suggest an improvement in both elastic and muscular artery properties and favorabe modifications of arterial wave reflection characteristics. Furthermore, HT improves lipoprotein metabolism and reduces coronary artery plaque formation in animal models. Unfortunately, observational and interventional studies in postmenopausal women that have evaluated the impact of HT on cardiovascular changes have produced inconsistent and inconclusive results. Most studies agree that arterial stiffness increases after menopause, partly due to advancing age and reduced estrogen production. Results from most studies that were designed to investigate the effects of HT on arterial properties have shown a selective decrease in elastic artery stiffness with little effect on muscular arteries. This beneficial effect was observed only if estrogen alone was administered. The main objective of this review is to discuss the ill effects of arterial stiffness in general and attempt to translate information from previous experimental studies to those in postmenopausal women and explain the beneficial effects of HT on arterial stiffness and improvement in left ventricular afterload.

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.

Aortic distensibility and dimensions and the effects of growth hormone treatment in the turner syndrome

In Turner's syndrome (TS), an increased risk for cardiovascular malformations exists, including aortic dilation of unknown cause. Abnormal biophysical wall properties may play an important role. Magnetic resonance imaging has been successfully used to assess aortic size and wall distensibility. The aim of this study was to assess aortic biophysical properties and dimensions in TS. Thirty-eight former participants of a growth hormone (GH) dose-response study in TS (mean age 12 +/- 2 years, mean body surface area 1.7 +/- 0.2 m2) and 27 controls (mean age 21 +/- 2 years, mean body surface area 1.8 +/- 0.1 m2) were enrolled. Previously, patients had been assigned to 1 of 3 groups treated with different GH dosages: group A (0.045 mg/kg/day), group B (0.067 mg/kg/day), and group C (0.09 mg/kg/day). All underwent magnetic resonance imaging > or =6 months after GH discontinuation to determine aortic dimensions and distensibility at 4 predefined levels: (1) the ascending aorta, (2) the descending aorta, (3) the level of the diaphragm, and (4) the abdominal aorta. Patients had larger aortic diameters at all but level 4 and tended to have reduced distensibility at level 3. Distensibility in group A was significantly less compared with that in group C at level 4. Compared with controls, patients in group A had larger aortic diameters at all but level 4 and reduced distensibility at level 4. The results for patients in groups B and C were not different from those for controls. In conclusion, patients with TS formerly treated with GH have dilated aortas and signs of impaired wall distensibility. The severity of abnormalities seems related to the GH dose, with a beneficial effect of a larger GH dose on the abnormalities.

Variations in carotid arterial compliance during the menstrual cycle in young women

The effect of menstrual cycle phase on arterial elasticity is controversial. In 10 healthy women (20.6+/-1.5 years old, mean+/-s.d.), we investigated the variations in central and peripheral arterial elasticity, blood pressure (carotid and brachial), carotid intima-media thickness (IMT), and serum oestradiol and progesterone concentrations at five points in the menstrual cycle (menstrual, M; follicular, F; ovulatory, O; early luteal, EL; and late luteal, LL). Carotid arterial compliance (simultaneous ultrasound and applanation tonometry) varied cyclically, with significant increases from the values seen in M (0.164+/-0.036 mm2 mmHg-1) and F (0.171+/-0.029 mm2 mmHg-1) to that seen in the O phase (0.184+/-0.029 mm2 mmHg-1). Sharp declines were observed in the EL (0.150+/-0.033 mm2 mmHg-1) and LL phases (0.147+/-0.026 mm2 mmHg-1; F=8.51, P<0.05). Pulse wave velocity in the leg (i.e. peripheral arterial stiffness) did not exhibit any significant changes. Fluctuations in carotid arterial elasticity correlated with the balance between oestradiol and progesterone concentrations. No significant changes were found in carotid and brachial blood pressures, carotid artery lumen diameter, or IMT throughout the menstrual cycle. These data provide evidence that the elastic properties of central, but not peripheral, arteries fluctuate significantly with the phases of the menstrual cycle.

Effects of Transdermal Estrogen Replacement Therapy on Cardiovascular Risk Factors

The prevalence of hypertension and cardiovascular disease increases dramatically after menopause in women, implicating estrogen as having a protective role in the cardiovascular system. However, recent large clinical trials have failed to show cardiovascular benefit, and have even demonstrated possible harmful effects, of opposed and unopposed estrogen in postmenopausal women. While these findings have led to a revision of guidelines such that they discourage the use of estrogen for primary or secondary prevention of heart disease in postmenopausal women, many investigators have attributed the negative results in clinical trials to several flaws in study design, including the older age of study participants and the initiation of estrogen late after menopause.Because almost all clinical trials use oral estrogen as the primary form of hormone supplementation, another question that has arisen is the importance of the route of estrogen administration with regards to the cardiovascular outcomes. During oral estrogen administration, the concentration of estradiol in the liver sinusoids is four to five times higher than that in the systemic circulation. This supraphysiologic concentration of estrogen in the liver can modulate the expression of many hepatic-derived proteins, which are not observed in premenopausal women. In contrast, transdermal estrogen delivers the hormone directly into the systemic circulation and, thus, avoids the first-pass hepatic effect.Although oral estrogen exerts a more favorable influence than transdermal estrogen on traditional cardiovascular risk factors such as high- and low-density lipoprotein-cholesterol levels, recent studies have indicated that oral estrogen adversely influences many emerging risk factors in ways that are not seen with transdermal estrogen. Oral estrogen significantly increases levels of acute-phase proteins such as C-reactive protein and serum amyloid A; procoagulant factors such as prothrombin fragments 1+2; and several key enzymes involved in plaque disruption, while transdermal estrogen does not have these adverse effects.Whether the advantages of transdermal estrogen with regards to these risk factors will translate into improved clinical outcomes remains to be determined. Two ongoing clinical trials, KEEPS (Kronos Early Estrogen Prevention Study) and ELITE (Early versus Late Intervention Trial with Estradiol) are likely to provide invaluable information regarding the role of oral versus transdermal estrogen in younger postmenopausal women.

Oestrogen and stroke in women: assessment of risk

The Women's Health Initiative reported an increased risk of stroke with hormone therapy, which has had a major effect on the use of these drugs. The increased risk was unexpected because research with animals showed that oestrogen reduces the extent of experimental strokes, and in human beings, oestrogen improves endothelial-dependent blood flow and lipid profiles. The mechanisms of risk might be related to oestrogen's proinflammatory and prothrombotic effects. However, the overall risk is still uncertain because of the complex actions of oestrogen at different doses, with or without progesterone, and the presence or absence of atherosclerotic risk factors. A similar debate about oral contraceptives and stroke risk in young women continues as data accumulate. Further studies are needed to identify the mechanisms of risk of stroke with oestrogen, as well as the risk factors that put women at particularly high risk of stroke with these hormones.

Pulse Pressure and Cardiovascular Events in Postmenopausal Women With Coronary Heart Disease

BACKGROUND

Pulse pressure (PP) has been shown to predict risk for cardiovascular events in men; however, this association has not been well established in women. Hormone replacement therapy may improve arterial compliance, but findings from cross-sectional and prospective studies report inconsistent results. We sought to examine the relationship between PP and risk for cardiovascular events, and to determine the effect of hormone therapy on PP in postmenopausal women with coronary heart disease (CHD).

METHODS AND RESULTS

A total of 2,763 postmenopausal women (mean age, 66 +/- 7 years [+/- SD]) with CHD in the Heart and Estrogen/Progestin Replacement Study, a randomized, placebo-controlled, secondary CHD prevention trial of estrogen plus progestin, were followed up on average for 4.1 years. BP was measured at baseline and annually. Mean baseline PP was 62 +/- 16 mm Hg. There were 361 myocardial infarctions (MIs) or CHD deaths, 265 hospitalizations for congestive heart failure (CHF), and 215 strokes or transient ischemic attacks (TIAs). Women in the highest quartile of PP at baseline had a 47% increase in risk for MI or CHD death and more than a twofold increase in risk for stroke and TIA events or hospitalization for CHF (p < 0.01 for each outcome). After adjustment for other cardiovascular risk factors and mean arterial pressure, PP remained significantly associated with incident stroke or TIA events (odds ratio, 1.25; p = 0.02) and hospitalizations for CHF (odds ratio, 1.31; p < 0.01) but not with MI or CHD death. After adjustment for diastolic BP, systolic BP was similarly associated with stroke or TIA (odds ratio, 1.30; p < 0.01) and hospitalized CHF (odds ratio, 1.30; p < 0.01) and was also weakly associated with risk for MI and CHD death (odds ratio, 1.18; p = 0.02). Mean PP was 1- to 2-mm Hg higher in women randomized to hormone replacement therapy vs those receiving placebo (p < 0.01).

CONCLUSIONS

PP had predictive value for CHF and stroke or TIA, but not MI or CHD death in this cohort of postmenopausal women with CHD. Use of hormone replacement therapy produced a small, statistically significant increase in PP. Further research is necessary to determine the clinical utility of PP as a potential therapeutic target.

Effect of hormone therapy and raloxifene on serum VE-cadherin in postmenopausal women

OBJECTIVE

To investigate the effect of continuous combined hormone therapy and raloxifene on serum VE-cadherin.

DESIGN

The study was double blinded, with a placebo run-in period of 28-50 days.

SETTING

University menopause clinic.

PATIENT(S)

Twenty-eight healthy postmenopausal women devoid of climacteric complaints.

INTERVENTION(S)

Subjects were randomized to 17beta-estradiol (2 mg) + norethisterone acetate (1 mg; E(2)-NETA) or raloxifene hCL (60 mg) for a period of 6 months.

MAIN OUTCOME MEASURE(S)

Serum VE-cadherin, which was estimated at baseline and at month 6.

RESULT(S)

Serum VE-cadherin decreased significantly in both E(2)-NETA and raloxifene groups (raloxifene baseline +/- SD: 1.17 +/- 0.44 ng/mL, 6 months: 0.82 +/- 0.29 ng/mL; E(2)-NETA baseline: 1.19 +/- 0.47 ng/mL, 6 months: 0.92 +/- 0.49 ng/mL). Percentage changes from baseline were -21.7 +/- 24.3 for E(2)-NETA and -26.0 +/- 20.6 for raloxifene.

CONCLUSION(S)

The effect of E(2)-NETA and raloxifene suggests that these drugs may preserve interendothelial junction integrity and control vascular permeability. Although this effect may influence the progress of the atheromatous lesion, its clinical impact on coronary artery disease (CAD) remains uncertain.

Should Progestins Be Blamed for the Failure of Hormone Replacement Therapy to Reduce Cardiovascular Events in Randomized Controlled Trials?

Many observational studies and experimental and animal studies have demonstrated that estrogen replacement therapy (ERT) or hormone replacement therapy (HRT) (estrogen plus progestin) significantly reduces the risk of coronary heart disease. Nonetheless, recent randomized controlled trials demonstrated some trends toward an increased risk of cardiovascular events rather than a reduction of risk. Recently, both the HRT and ERT arms of the Women’s Health Initiative (WHI) study were terminated early because of an increased/no incidence of invasive breast cancer, increased incidence of stroke, and increased trend/no protective effects of cardiovascular disease. We discuss the controversial effects of HRT and ERT on cardiovascular system and provide a hypothesis that the failure of HRT and ERT in reducing the risk of cardiovascular events in postmenopausal women might be because of the stage of their atherosclerosis at the time of initiation of HRT or ERT.

The effect of hormone therapy and raloxifene on serum matrix metalloproteinase-2 and -9 in postmenopausal women

OBJECTIVE

The aim of the study was to investigate the effect of continuous-combined hormone therapy and raloxifene on the total and active forms of serum matrix metalloproteinase (MMP) -2 and -9.

DESIGN

The study was double-blinded, with a placebo run-in period of 28 to 50 days. Twenty-eight women received either 17beta-estradiol 2 mg + norethisterone acetate 1 mg (E2/NETA) or raloxifene HCL 60 mg for a period of 6 months. Total and active forms of MMP-2 and -9 were estimated at baseline and at month 6.

RESULTS

Total MMP-2 increased significantly in both E2/NETA and raloxifene groups (raloxifene baseline: 278.1 +/- 18.1 ng/mL; 6 months: 303.1 +/- 29.9 ng/mL, P = 0.008) (E2/NETA baseline: 281.9 +/- 27.5 ng/mL; 6 months: 298.8 +/- 12.7 ng/mL, P = 0.025). Similarly, both treatments increased the active MMP-2 fraction, although only the raloxifene-associated increase acquired significance (raloxifene baseline: 24.9 +/- 8.6 ng/mL; 6 months: 31.6 +/- 15.3 ng/mL, P = 0.045) (E2/NETA baseline: 21.7 +/- 5.7 ng/mL; 6 months: 27.4 +/- 5.8 ng/mL, P = 0.128). Total as well as active fractions of MMP-9 were not significantly affected by either treatment.

CONCLUSIONS

Both E2/NETA and raloxifene increased the total and active MMP-2 serum levels. MMP-9 was not significantly affected by either regimen. Larger, long-term clinical trials are needed to elucidate the effect of HT and raloxifene on MMPs and the possible clinical implications for cardiovascular health.

[Impact of HRT on the arterial carotid vascular tree]

Hormone replacement therapy (HRT) and arterial impact, this is a controversial subject since it is a large field that needs weeding, a theme in which new questions are raised by the cross-results of various studies conducted, and in which doubt is perhaps one of, or even the only, certitude that all the various specialists agree on. In this controversial climate, we feel that three important points should be underlined: the American studies, however reliable they may be, have been conducted with conjugated estrogens and the generalisation to the results of other types of hormones such as those prescribed in Europe is perhaps a little hasty; other factors of risk should be taken into consideration in the eventual potentialisation of the risk induced by such treatment; the venous and arterial vascular risks are not based on the same physiopathological mechanisms. Hence the increased risk in one or the other network system should perhaps not be amalgamated either.