Estrogen and postmenopausal estrogen/progestin therapy: effect on endothelium-dependent prostacyclin, nitric oxide and endothelin-1 production

Chorioretinal biomarkers in hypothalamic amenorrhea

PURPOSE

The aim of our study was to evaluate changes in the retinal and choriocapillaris circulations in patients with hypothalamic amenorrhea.

METHODS

Prospective, cross-sectional observational study on 25 patients (50 eyes) diagnosed with hypothalamic amenorrhea and 25 age-matched healthy women. Optical coherence tomography angiography (OCTA) was used to evaluate the vessel density (VD) of superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris VD layers in whole 6.4 × 6.4-mm image and in fovea grid-based image. In patients' group, systemic parameters were collected: body mass index (BMI), endometrial rhyme thickness, follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, insulin, and cortisol.

RESULTS

SCP and DCP did not show any statistical difference when comparing patients and controls (all p > 0.05). Differently, choriocapillaris VD in the whole region showed a non-significant tendency toward higher values in the patients group in both eyes (p = 0.038 for right eye [RE], p = 0.044 for left eye [LE]). Foveal choriocapillaris VD was higher in hypothalamic amenorrhea women vs. healthy controls (66.0 ± 2.4 vs. 63.7 ± 6.6%, p = 0.136 for RE; 65.0 ± 2.4 vs. 61.6 ± 7.0%, p = 0.005 for LE). Focusing on correlation with systemic parameters, SCP and DCP foveal density had a medium/high effect size with endometrial rhyme, along with DCP in the fovea area vs. cortisol and SCP in the whole area vs. FSH.

CONCLUSION

When comparing hypothalamic amenorrhea patients to healthy subjects, OCTA detected changes in the choriocapillaris layer, showing increased VD in the early stage of the systemic pathology, suggesting that microvascular "compaction" could be a first phase of hypoestrogenism adaptation.

Retinal and choroidal microvascular changes during pregnancy detected with optical coherence tomography angiography: a prospective study

PURPOSE

To investigate choroidal and retinal blood flow and thickness changes using optical coherence tomography and optical coherence tomography angiography during pregnancy.

DESIGN

Prospective and case-control study between June 2020 and June 2021.

METHODS

This prospective study included 41 eyes of 41 pregnant females and 45 eyes of 45 healthy nonpregnant females. Ocular perfusion pressure, retinal thickness, choroidal thickness, foveal avascular zone (FAZ) area, superficial and deep capillary plexuses (SCP and DCP, respectively), vessel density (VD), and choriocapillaris (CC) VD measurements were evaluated with optical coherence tomography and optical coherence tomography angiography.

RESULTS

There was no significant difference in ocular perfusion pressure, retinal thickness, and choroidal thickness during pregnancy. The FAZ area increased as the gestational weeks progressed (p = 0.011). The FAZ area in the first trimester was significantly smaller than that in the control group (p = 0,029). A decrease in the central SCP and DCP VD in the third trimester and an increase in the CC VD during pregnancy were detected (p = 0.01, p < 0.001, and p < 0.001, respectively). We observed an increase in mean VD for both the SCP and DCP in the second trimester (p = 0.02 and p = 0.027, respectively). In the second and third trimesters, the SCP and DCP VD values were found to be significantly higher than in the control group. During the pregnancy, a significant increase in CC VD was detected.

CONCLUSION

This is the first prospective study in the literature that evaluates the measurements in all trimesters of pregnancy with optical coherence tomography angiography. We observed significant retinal and choroidal microvascular changes between trimesters of pregnancy and when compared with healthy females.

Orbital and ocular perfusion in thyroid eye disease

Thyroid eye disease (TED) is characterized by enlargement of extraocular muscles, an increase in retrobulbar fat, orbital fibrosis, and fluctuations in plasma thyroid hormone levels in most patients, often associated with raised autoantibody titers. The occurrence of orbital space conflict compromises the orbital perfusion, unchecked progression of which results in irreversible loss of visual acuity and visual fields. The quantitative assessment of orbital perfusion can be done by measurement of blood flow velocities in the superior ophthalmic vein (SOV), ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary artery by color Doppler imaging. The retinal and choroidal microvasculature is studied by optical coherence tomography and optical coherence tomography angiography. The orbital and ocular perfusion fluctuates during the course of TED. Orbital congestion is reflected by the reduction or reversal of SOV flow and an increase in subfoveal choroidal thickness. The active phase is characterized by high blood flow velocities of the OA and CRA. The onset of dysthyroid optic neuropathy is associated with reduced arterial perfusion and reduction in parafoveal and peripapillary vascular density. Orbital decompression improves the SOV flow and decreases the resistivity index of CRA. Sequential evaluation of orbital hemodynamic changes can thus supplement the clinical scoring systems for monitoring and planning intervention in TED.

ET-1 as a Sex-Specific Mechanism Impacting Age-Related Changes in Vascular Function

Aging is a primary risk factor for cardiovascular disease (CVD), which is the leading cause of death in developed countries. Globally, the population of adults over the age of 60 is expected to double by the year 2050. CVD prevalence and mortality rates differ between men and women as they age in part due to sex-specific mechanisms impacting the biological processes of aging. Measures of vascular function offer key insights into cardiovascular health. Changes in vascular function precede changes in CVD prevalence rates in men and women and with aging. A key mechanism underlying these changes in vascular function is the endothelin (ET) system. Studies have demonstrated sex and sex hormone effects on endothelin-1 (ET-1), and its receptors ETA and ETB. However, with aging there is a dysregulation of this system resulting in an imbalance between vasodilation and vasoconstriction. Thus, ET-1 may play a role in the sex differences observed with vascular aging. While most research has been conducted in pre-clinical animal models, we describe more recent translational data in humans showing that the ET system is an important regulator of vascular dysfunction with aging and acts through sex-specific ET receptor mechanisms. In this review, we present translational evidence (cell, tissue, animal, and human) that the ET system is a key mechanism regulating sex-specific changes in vascular function with aging, along with therapeutic interventions to reduce ET-mediated vascular dysfunction associated with aging. More knowledge on the factors responsible for the sex differences with vascular aging allow for optimized therapeutic strategies to attenuate CVD risk in the expanding aging population.

The thickness changes of retina in high myopia patients during the third trimester of pregnancy: a pilot study

Objectives

To observe and compare the difference in retinal thickness using optical coherence tomography (OCT) between patients with high myopia (HM) during the third trimester of pregnancy and age-matched HM non-pregnant women.

Methods

A case-control study. A total of 39 eyes from 39 HM women in the third trimester (study group) and 50 eyes of 50 age-matched non-pregnant women with HM (control group) were included. All subjects underwent SD-OCT examination. The built-in software was used to measure the retinal thickness in macular region. The data from two groups were compared using independent-samples t test.

Results

Among the 89 subjects in this study, the mean gestational age of the study group was 35.09 ± 2.44 weeks, and the average age was 32.24 ± 3.75 years. The average age of the control group was 34.04 ± 7.19 years old. Compared with the control group, the average thickness of parafoveal area, and the average thickness of parafoveal superior, inferior, temporal quadrants of the superficial retina and the average thickness of the foveal and parafoveal of the superficial retina were significantly decreased in the study group (P < 0.05). Compared with the control group, the average thickness of all quadrants of the retina in the parafoveal area except the nasal quadrant were significantly decreased in the study group (P < 0.05).

Conclusions

In this observational study, the retinal thickness of patients with high myopia during the third trimester of pregnancy was thinner than that of non-pregnant women with age-matched high myopia.

Roles of Genetic Predisposition in the Sex Bias of Pulmonary Pathophysiology, as a Function of Estrogens : Sex Matters in the Prevalence of Lung Diseases

In addition to studies focused on estrogen mediation of sex-different regulation of systemic circulations, there is now increasing clinical relevance and research interests in the pulmonary circulation, in terms of sex differences in the morbidity and mortality of lung diseases such as inherent-, allergic- and inflammatory-based events. Thus, female predisposition to pulmonary artery hypertension (PAH) is an inevitable topic. To better understand the nature of sexual differentiation in the pulmonary circulation, and how heritable factors, in vivo- and/or in vitro-altered estrogen circumstances and changes in the live environment work in concert to discern the sex bias, this chapter reviews pulmonary events characterized by sex-different features, concomitant with exploration of how alterations of genetic expression and estrogen metabolisms trigger the female-predominant pathological signaling. We address the following: PAH (Sect.7.2) is characterized as an estrogenic promotion of its incidence (Sect. 7.2.2), as a function of specific germline mutations, and as an estrogen-elicited protection of its prognosis (Sect.7.2.1). More detail is provided to introduce a less recognized gene of Ephx2 that encodes soluble epoxide hydrolase (sEH) to degrade epoxyeicosatrienic acids (EETs). As a susceptible target of estrogen, Ephx2/sEH expression is downregulated by an estrogen-dependent epigenetic mechanism. Increases in pulmonary EETs then evoke a potentiation of PAH generation, but mitigation of its progression, a phenomenon similar to the estrogen-paradox regulation of PAH. Additionally, the female susceptibility to chronic obstructive pulmonary diseases (Sect. 7.3) and asthma (Sect.7.4), but less preference to COVID-19 (Sect. 7.5), and roles of estrogen in their pathogeneses are briefly discussed.

Ocular vascular changes during pregnancy: an optical coherence tomography angiography study

BACKGROUND

Pregnancy is a period presenting with many physiological adaptation mechanisms. One of the structures in which these mechanisms are observed is ocular tissues. The cornea, lacrimal and meibomian glands, and chorioretinal complex are all among the structures affected by changes during pregnancy. In this study we aimed to evaluate the macular and optic disc vessel density (VD) changes by Optical Coherence Tomography Angiography (OCTA) imaging in pregnancy.

METHODS

A total of 248 eyes from 124 pregnant women and 80 eyes from 40 healthy control women were involved. Vessel densities of macula were evaluated for superficial capillary plexus (SCP) and deep capillary plexus (DCP) in whole macula, foveal, parafoveal and perifoveal region. Peripapillary and whole optic disc VDs were also evaluated. Vessel densities of macula and optic disc were compared between control individuals and pregnant women. Vessel densities in different trimesters were also evaluated.

RESULTS

Modest but significant differences in VDs of whole macula of SCP and DCP were observed in pregnancy group. Additionally, perifoveal and parafoveal region of SCP, whole disc and radial peripapillary capillary VD were significantly higher in pregnancy group. There was no correlation between VD ratios of macula and optic disc and pregnancy weeks and trimesters.

CONCLUSIONS

This is the first study focusing on the OCTA parameters in pregnant individuals. These findings suggest that physiological changes during pregnancy are not limited to the cornea, eyelids and the choroid but also to the retinal and optic disc vasculature.

Can improvement in hormonal and energy balance reverse cardiovascular risk factors in athletes with amenorrhea?

Female athletes display a high prevalence of hypothalamic amenorrhea as a result of energy imbalance. In these athletes with amenorrhea, decreased luteinizing hormone/follicule-stimulating hormone secretion leads to deficiency in endogenous estrogen. The severe estrogen deficiency in these athletes may increase cardiovascular risk similar to that in postmenopausal women. This review discusses the potential cardiovascular risk factors in athletes with amenorrhea as a result of hypoestrogenism, which include endothelial dysfunction and unfavorable lipid profiles. We also consider the potential to reverse the cardiovascular risk by restoring energy or hormonal imbalance along the reproductive axis in athletes with amenorrhea.

The Association between Female Reproductive Factors and Open-Angle Glaucoma in Korean Women: The Korean National Health and Nutrition Examination Survey V

Purpose

We investigated associations between female reproductive factors and open-angle glaucoma (OAG) in Korean females using the Korea National Health and Nutrition Examination Survey (KNHANES).

Methods

A nationwide, population-based, cross-sectional study was conducted. We enrolled 23,376 participants from the KNHANES who had undergone ophthalmologic exams from 2010 through 2012. Associations between undiagnosed OAG and female reproductive factors such as age at menarche and menopause, parity, history of lactation, and administration of oral contraceptives (OC) or hormone replacement therapy (HRT) were determined using stepwise logistic regression analyses.

Results

Of the enrolled participants, 6,860 participants (397 with OAG and 6,463 without OAG) met our study criteria and were included in the analyses. In the multivariate logistic regression analysis after adjusting for all potential confounding factors, only early menopause (younger than 45 years) was significantly associated with OAG in participants with natural menopause (OR 2.28, 95% CI 1.17–4.46). Age at menarche, parity, history of lactation, and administration of OC or HRT were not significantly associated with OAG.

Conclusions

Only early menopause was associated with an increased risk of OAG in our study, in contrast to previous Western studies reporting both early menopause and late menarche as associated factors.

Effect of short-term estrogen therapy on endothelial function: a double-blinded, randomized, controlled trial

OBJECTIVE

To evaluate the effect of short-term hormone replacement therapy with 0.625 mg conjugated estrogens daily on endothelial function of healthy postmenopausal women, using flow-mediated dilation (FMD) of the brachial artery.

METHODS

We performed a double-blinded, randomized, controlled trial over 3 years. Randomization was performed using computer-generated sorting. All participants were blinded to the use of conjugated equine estrogens (CEE) or placebo and FMD was assessed by a blinded examiner, before and after 28 days of medication. A total of 64 healthy postmenopausal women were selected and randomly assigned into two groups of treatment: 0.625 mg of CEE or placebo.

RESULTS

FMD values were statistically different between the groups (p = 0.025): the group receiving CEE showed a FMD value of 0.011 compared to the placebo group (FMD = -0.082). The two groups were additionally evaluated for homogeneity through the Shapiro-Wilk test in respect to variables that could interfere with endothelial function such as age (p = 0.729), body mass index (p = 0.891), and time since menopause (p = 0.724). Other variables were excluded during selection of the participants such as chronic vascular conditions, smoking, and sedentary lifestyle.

CONCLUSION

Our results demonstrate that the administration of 0.625 mg CEE for 28 days is effective in improving vascular nitric oxide-dependent dilation assessed by FMD of the brachial artery in postmenopausal women.

CLINICAL TRIAL REGISTRATION

NCT01482416.

Ocular blood flow in polycystic ovary syndrome

AIM

The aim of this study was to evaluate whether the presence of polycystic ovary syndrome (PCOS) alters ocular blood flow parameters.

MATERIAL AND METHODS

Color Doppler imaging of the orbital vessels was performed in 41 eyes of 41 patients with PCOS. Forty-eight eyes of 48 age-matched volunteers served as controls. The ophthalmic artery (OA), the central retinal artery and the posterior ciliary artery were examined. Ocular blood flow indices of the peak systolic velocity, diastolic velocity, end-diastolic velocity, systolic/diastolic ratio, resistive index and pulsatility index were computed.

RESULTS

The peak systolic velocity, diastolic velocity and end-diastolic velocity of the OA, central retinal artery and posterior ciliary artery were significantly increased in PCOS patients in comparison to the controls (all P < 0.001). The mean systolic/diastolic ratio, resistive index and pulsatility index of the OA in PCOS patients were significantly decreased (all P < 0.05). Ocular blood flow velocity was positively correlated with serum luteinizing hormone, follicle-stimulating hormone and total cholesterol levels. There was a significant negative correlation between serum glucose and insulin levels and ocular blood flow velocity.

CONCLUSION

Ocular blood flow velocity is increased in PCOS patients and vascular resistance seems to decrease only in the OA.

Postmenopausal hypertension and sodium sensitivity

It has been well established that women generally have lower incidence rates of hypertension than men at similar ages and these differences may vary with age. It also has been observed in many studies that after menopause, blood pressure (BP) increases in women to levels even higher than in men. The lack of estrogens may not be suggested as the only component involved in the development of postmenopausal hypertension. Thus, in this mini-review, the possible mechanisms by which sex hormones may influence the BP are discussed. This review also examines the renal regulatory mechanisms for gender differences in BP and explores the effects of salt intake on BP (salt-sensitivity) in pre and post-menopausal women.

Estrogen has been shown to stimulate nitric oxide (NO) production, thus female sex hormones have a beneficial effect on BP control. Evidences that angiotensin type 2 receptor (AT₂R) is up-regulated by estrogen support the favorable effects on BPs in women than men. The kidney plays an integral role in the regulation of arterial pressure through the mechanism of pressure-natriuresis, which has been shown to be modulated by the RAS. The prevalence of salt-sensitivity increases with age and low-salt diets has shown to help reduce systolic BP (SBP) and diastolic BP. While oral hormone replacement therapy has yielded only a neutral or minimal effect on the elevation of SBP, both the transdermal route replacement and a novel progestin with anti-aldosterone activity (drospirenone) has also shown to reduce SBP.

Doppler of the uterine arteries combined with endometrial thickness correlate well with the degree of pituitary suppression in women treated with long-acting GnRH agonists

PURPOSE

The aim of this study was to evaluate the use of Doppler velocimetry of the uterine arteries and its association to endometrial thickness as a method to confirm pituitary suppression after administration of gonadotropin-releasing hormone analogues in assisted reproduction treatment cycles.

METHODS

A total of 70 patients using gonadotropin-releasing hormone analogues for pituitary suppression for in vitro fertilization treatment were studied. To confirm down-regulation, serum estradiol levels and endometrial thickness were evaluated 10 days after gonadotropin-releasing hormone analogues administration. When estradiol was <30 pg/ml and endometrial thickness was <3 mm, pituitary suppression was confirmed. Doppler velocimetric measurements were performed at the same day to study the pulsatility index of the uterine arteries, until pituitary suppression was confirmed.

RESULTS

All 70 patients had normal ovarian morphology. For the patients who had estradiol levels ≤30 pg/ml, the mean pulsatility index of the uterine arteries was 2.95 ± 0.79 and for those who had levels >30 pg/ml the mean PI was 2.22 ± 0.8 (p = 0.005). For the patients who had endometrial thickness ≤5 mm the mean PI was 2.86 ± 0.82 and for those with endometrial thickness >5 mm the mean PI was 2.17 ± 0.79 (p = 0.004). Using a cut-off point of 2.51 for the pulsatility index, to compare to estradiol levels, we observed a sensitivity of 72.7 % and specificity of 71 %. The combination of Doppler velocimetric and endometrial thickness showed a sensitivity of 94 % and specificity of 82.3 %.

CONCLUSIONS

Doppler velocimetric analysis of the uterine arteries can be an important tool in the diagnosis of the down-regulation after the use of gonadotropin-releasing hormone analogues and might help simplify assisted reproduction programmes.

Dydrogesterone does not reverse the cardiovascular benefits of percutaneous estradiol

OBJECTIVE

To evaluate the influence of dydrogesterone on estimated cardiovascular risk of users of hormone replacement therapy (HRT) (with percutaneous 17β-estradiol in monotherapy and in combination with dydrogesterone) and HRT non-users through the Framingham score tool for a period of 2 years.

METHODS

Framingham scores were calculated from the medical records of patients treated for at least 2 years with 17β-estradiol alone or in combination with dydrogesterone, along with HRT non-users, through the analysis of patient medical records, followed for at least 2 years at Instituto Estadual de Diabetes e Endocrinologia Luiz Capriglione.

RESULTS

Improvements in lipid profile, glucose and blood pressure levels, which reduced the estimated cardiovascular risk, were observed in the 17β-estradiol group. Similar changes were observed in the users of 17β-estradiol + dydrogesterone, suggesting that this progestogen does not attenuate the effects caused by 17β-estradiol.

CONCLUSIONS

Both HRT groups showed a reduction in their Framingham score. In contrast to data from other HRT investigations on cardiovascular risk, these formulations proved to be safe, even in the first year of use.

Histopathological effects of estrogen deficiency on larynx mucosa in ovariectomised rats

Laryngeal manifestations due to estrogen deficiency have been studied in the literature. But to date, the possible histopathological changes of laryngeal mucosa due to estrogen deficiency have not been studied. Therefore, our objective was to determine the histopathological changes of laryngeal mucosa in ovariectomised rats in order to clarify effects of estrogen deficiency on laryngeal tissue. The study is a randomized trial and was conducted at the animal care facility of Haydarpasa Numune Education and Research Hospital. Twenty-one Wistar rats were used throughout the experiment. There were six rats in the sham-operated control group. And others were divided into two groups (4, 8 weeks) according to follow-up time after ovariectomy. We observed significant changes 4 weeks after ovariectomy when we assessed subepithelial edema, inflammation, cilia and goblet cell loss (p < 0.01). It was shown that estrogen deficiency after ovariectomy in rats caused changes in laryngeal tissue when it was studied histopathologically.

Menstrual phase-related differences in the pulsatility index on the central retinal artery suggest an oestrogen vasodilatation effect that antagonizes with progesterone

PURPOSE

The actual effect of steroid hormones on cerebral microcirculation is still controversial. Therefore, the aim of our study was to investigate vascular flow variations in the central retinal artery that may exist during the ovulatory menstrual cycle.

METHODS

A total of 34 healthy women were included in this observational, longitudinal, and prospective study. All participants were submitted to dopplerfluxometric evaluation of the eyes in order to study the pulsatility index (PI) of the central retinal arteries, during four phases of the menstrual cycle: early follicular, mid follicular, periovulatory, and mid luteal phases.

RESULTS

Subjects' ages ranged from 14 to 47 years old (mean: 29.7 ± 10.1) and PI did not differ among age groups. The PI of the central retinal artery was different among the four phases of the menstrual cycle. PI showed a significant decrease from early follicular phase (1.72) to mid follicular phase (1.57) (p = 0.037), and was similar during periovulatory phase (1.56) and significantly increased in mid luteal phase (1.70). After that it returned to the values observed in the early follicular phase.

CONCLUSION

Our results suggest the existence of an oestrogen vasodilatation effect on the central retinal artery that is menstrual phase-related and antagonized by progesterone.

Endothelin in the female vasculature: a role in aging?

Cardiovascular diseases are the leading cause of morbidity and mortality in the world. Aging is associated with an increased incidence of cardiovascular disease. Premenopausal women are relatively protected from vascular alterations compared with age-matched men, likely due to higher levels of the female sex hormones. However, these vasoprotective effects in women are attenuated after menopause. Thus, the vascular system in aging women is affected by both the aging process as well as loss of hormonal protection, positioning women of this age group at a high risk for cardiovascular diseases such as hypertension, myocardial infarction, and stroke. The endothelin system in general and endothelin-1 (ET-1) in particular plays an important role in the pathogenesis of vascular dysfunction associated with aging. Evidence suggests that the female sex steroids can interfere with the vascular expression and actions of ET-1 via several mechanisms, which may further contribute to pathological processes in the vasculature of aging women. In this review, we have summarized hormone-dependent vascular pathways whereby ET-1 may mediate the deleterious effects of aging in postmenopausal females.

Evaluation of hormone replacement therapy which may have an adrenomedullin-mediated protective effect on cardiovascular disorders

BACKGROUND AND AIMS

This study aimed to determine whether there is an adrenomedullin (AM)-mediated protective effect of postmenopausal estrogen/progestin therapy (HRT) against cardiovascular disorders.

METHODS

A total of 22 post-menopausal women without hysterectomy undergoing postmenopausal symptoms (aged 43-52) were treated with conjugated equine estrogen (0.625 mg/die) plus medroxyprogesterone acetate (2.5 mg/die) for six months. The flow velocity of the right middle cerebral artery [measured as resistance index (RI) and pulsatility index (PI)], plasma levels of adrenomedullin and endothelin- 1 (ET-1), mean baseline ratio of AM to ET-1, and lipid profiles were assessed before and after HRT.

RESULTS

A statistically significant difference was found for triglycerides, total cholesterol, AM/ET-1 ratio and right middle cerebral artery PI (p<0.05), without any significant differences in HDL, LDL, AM, ET-1, systolic blood pressure, diastolic blood pressure, a right middle cerebral artery RI (p>0.05) between pre- and post- HRT.

CONCLUSIONS

Adrenomedullin may be added to other vasoactive peptides as a new potential candidate for HRT-mediated vascular protection. The ratio of AM/ET-1 vs AM or ET-1 alone may be a useful biological marker of this protection.

Emerging Selective Estrogen Receptor Modulators

Menopause, regardless of age at onset, is associated with a marked increase in coronary heart disease (CHD) risk. On the basis of epidemiological studies that demonstrated mainly positive effects of postmenopausal hormone therapy on CHD as well as on risk markers of CHD, it has been suggested that CHD could be prevented in postmenopausal women with long-term hormone therapy. However, since the publications of the Heart and Estrogen/progestin Replacement Study and the Women's Health Initiative trial, prescription of hormone therapy for the prevention of CHD has become controversial. Major efforts have been made to identify alternatives for hormone therapy. Compounds suggested have included selective estrogen receptor modulators (SERMs), which represent a class with a growing number of compounds that act as either estrogen receptor agonists or antagonists in a tissue-specific manner. This pharmacological profile may offer the opportunity to dissociate favourable estrogenic effects on the bone and cardiovascular system from unfavourable stimulatory effects on the breast and endometrium. Two SERMs presently on the market are tamoxifen and raloxifene. The only data available regarding the effects of tamoxifen on cardiovascular events in postmenopausal women are from breast cancer trials. These trials found fewer fatal myocardial events in women randomly assigned to tamoxifen compared with women assigned to placebo. Raloxifene is a second-generation SERM that has been shown to prevent osteoporotic fractures, is safe for the endometrium and holds high promise for the prevention of breast cancer. The effect of raloxifene on CHD is still uncertain. On the basis of the MORE (Multiple Outcomes of Raloxifene Evaluation) trial, raloxifene may offer some protection to women with CHD or to those who are at high risk of CHD. Proof that raloxifene reduces the risk of CHD requires a clinical trial with hard clinical endpoints. Such a study is currently underway. Next-generation SERMs taken into clinical development include idoxifene, droloxifene, ospemifene, arzoxifene, acolbifene/EM-800, levormeloxifene, lasofoxifene, bazedoxifene and HMR 3339. The aim is to find a compound with the ideal profile, that is, alleviation of climacteric symptoms and prevention of osteoporotic fractures, but without an adverse effect on the breast and endometrium, and no negative effect or even a beneficial effect on the cardiovascular system and the brain. Currently, limited data are available with regard to these next-generation SERMs and CHD. Nevertheless, some of these novel agents provide arguments for continuing the search for an ideal SERM.

Controversies about HRT--lessons from monkey models

Lessons from monkey models contribute significantly to a better understanding of the controversies in reconciling the differences in postmenopausal hormone treatment outcomes between observational and randomized trial data. Monkey studies brought attention to premenopausal estrogen deficiency with resulting premature coronary artery atherosclerosis. Recently, those monkey studies were confirmed for premenopausal women in the NHLBI-sponsored Women's Ischemia Syndrome Evaluation (WISE) Study. Monkey studies have provided convincing evidence for the primary prevention of coronary artery atherosclerosis when estrogens are administered soon after the development of estrogen deficiency. Equally convincing are the data from monkey studies indicating the total loss of these estrogens beneficial effects if treatment is delayed for a period equal to six postmenopausal years for women. An attempt has been made using the monkey model to identify the hormone treatment regimen most effective in preventing the progression of coronary artery atherosclerosis. By a substantial margin, the most effective approach is that of using estrogen containing oral contraceptive during the perimenopausal transition, followed directly by hormone replacement therapy postmenopausally. Because of similarities between human and nonhuman breast, monkeys have had a major role in clarifying controversies surrounding the breast cancer risk of estrogen only versus estrogen plus progestin therapies. The results of monkey studies suggest little or no effects of estrogen only treatment; whereas, estrogen+progestin clearly increases breast cancer risk.

Hormone replacement therapy and cardiovascular risk

Hormone replacement therapy (HRT) is effective in suppressing postmenopausal symptoms and, in the past, many have claimed that it is cardioprotective. It was thought that the lower incidence of cardiovascular disease in premenopausal women was related to the cardioprotective effect of estrogen. Many of these studies were, however, observational studies. HRT alters many cardiovascular parameters, most beneficially. The mixed effect on these parameters make the overall result on cardiovascular risk difficult to predict. However, recent randomized, placebo-controlled trials have shown not only that HRT does not confer cardioprotection, but that it actually increases one's cardiovascular risk in the short term. Based on the current evidence, HRT should not be recommended in the hope that it will protect postmenopausal women against coronary heart disease.

Effect of the menstrual cycle on standard achromatic and blue-on-yellow visual field analysis of women with migraine

BACKGROUND

It has been postulated that migraine and glaucoma may have common vascular causative factors. Significant sex-based differences in the incidence of many important ocular conditions raise the possibility that estrogens may have direct effects on the eye. We performed a study to determine the effect of the menstrual cycle on standard achromatic automated perimetry (SAP) and short-wavelength automated perimetry (SWAP) (blue-on-yellow perimetry) of women with migraine.

METHODS

Both eyes of 73 normally menstruating women (31 subjects with migraine and 42 healthy control subjects) were included in the study. Subjects underwent a complete ocular examination including SAP and SWAP in both the follicular phase (12th to 13th day of the cycle) and the luteal phase (1 to 2 days before the onset of bleeding) of two consecutive menstrual cycles.We performed visual field analysis using the Humphrey Field Analyzer II with the full-threshold central 30-2 program. Mean sensitivity was calculated for the superior temporal, inferior temporal, superior nasal and inferior nasal regions separately.

RESULTS

Thirteen subjects were lost to follow-up (5 in the migraine group and 8 in the control group), leaving 26 subjects and 34 subjects respectively. There was no significant difference in mean age between the two groups (33.9 years [standard deviation (SD) 3.4 years] vs. 35.1 years [SD 3.3 years]). The mean duration of migraine was 7.6 (SD 3.1) years (range 3-14 years). In both groups, serum estradiol levels were significantly lower (p = 0.001) and serum progesterone levels were significantly higher (p < 0.001) in the luteal phase than in the follicular phase. In the control group, the mean sensitivity values with SWAP were significantly lower in the luteal phase than in the follicular phase (p = 0.04). A similar decrease was observed for the subjects with migraine with both SAP and SWAP (p = 0.01). There was no difference in regional mean sensitivity between the two phases with either perimetric test in the control group. For the subjects with migraine, there was no difference in regional mean sensitivity between the two phases with SAP. However, with SWAP, the mean sensitivity for the nasal visual field locations was significantly lower in the luteal phase than in the follicular phase (p = 0.01).

INTERPRETATION

Our study provides further evidence of an effect of sex hormones on the visual field of women with migraine. In addition to assessment of intraocular pressure, menstrual cycle phases should be considered in women with migraine at risk for glaucomatous optic neuropathy.

HMR 3339, a novel selective estrogen receptor modulator, reduces total cholesterol, low-density lipoprotein cholesterol, and homocysteine in healthy postmenopausal women

OBJECTIVE

To investigate the short-term effects of HMR 3339 in comparison with raloxifene and placebo on cardiovascular risk factors.

DESIGN

A multicenter, randomized, placebo-controlled, double-blind, dose-ranging study.

SETTING

Gynecologic outpatient department.

PATIENT(S)

One hundred eighteen healthy nonhysterectomized postmenopausal women.

INTERVENTION(S)

Participants received daily placebo (n = 22), 2.5 mg of HMR 3339 (n = 25), 10 mg of HMR 3339 (n = 24), 50 mg of HMR 3339 (n = 24), or 60 mg of raloxifene (n = 23) for 12 weeks followed by a 2-week washout period.

MAIN OUTCOME MEASURE(S)

Blood concentrations of lipids measured at baseline, and after 2, 4, 8, 12, and 14 weeks, and of lipoprotein(a), homocysteine, and endothelin-1 measured at baseline, and after 4 and 12 weeks.

RESULT(S)

After 12 weeks of treatment with HMR 3339, compared with placebo, serum total cholesterol was reduced (10 mg of HMR 3339: -9.7%; 50 mg of HMR 3339: -15.2%), low-density lipoprotein (LDL)-cholesterol (10 mg of HMR 3339: -10.8%; 50 mg of HMR 3339: -24.2%) and plasma homocysteine concentrations (2.5 mg of HMR 3339: -3.9%; 10 mg of HMR 3339: -10.8%; 50 mg of HMR 3339: -13.8%), suggesting a dose-dependent effect of HMR 3339. These effects were already apparent after 2 weeks of treatment for total cholesterol and LDL-cholesterol, and after 4 weeks of treatment for homocysteine. After 12 weeks, raloxifene, compared with placebo, significantly decreased total cholesterol (-10.5%), LDL-cholesterol (-15.0%), and triglycerides (-16.9%), but not homocysteine. High-density lipoprotein-cholesterol, lipoprotein(a), and endothelin-1 showed no significant changes in any of the active treatment groups.

CONCLUSION(S)

HMR 3339 reduces total cholesterol, LDL-cholesterol, and homocysteine concentrations in postmenopausal women.

The influence of sex hormones on ocular blood flow in women

PURPOSE

To investigate the influence of sex hormones on ocular haemodynamics, blood flow velocities in the ophthalmic and central retinal arteries and serum levels of sex hormones were measured in pre- and postmenopausal women.

METHODS

Colour Doppler imaging (CDI) was used to determine the flow velocities (peak systolic velocity [PSV] and end-diastolic velocity [EDV]) and the resistive index (RI) in the ophthalmic and central retinal arteries in 22 premenopausal and 32 postmenopausal women, who had never received hormone replacement therapy. Serum levels were measured for oestradiol, free testosterone and follicle-stimulating hormone. The CDI parameters were compared between the two groups and the influence of serum levels of oestradiol and testosterone on blood flow velocities and the resistive indices were analysed.

RESULTS

After correcting for age and mean arterial blood pressure, an analysis of covariance disclosed a significantly lower EDV (p=0.02) and a significantly higher RI (p=0.01) in the central retinal artery of postmenopausal women compared with premenopausal women. Partial correlation analysis, controlling for age, revealed significant correlations between the CDI parameters and serum levels of oestradiol and testosterone. For premenopausal women, PSV (r=0.58, p=0.04) and EDV (r=0.73, p=0.006) in the ophthalmic artery correlated positively with serum oestradiol levels. The RI in the central retinal artery decreased with increasing oestradiol levels in both groups (premenopausal r= -0.40, p=0.04; postmenopausal r= -0.32, p=0.05). Peak systolic velocity in the central retinal artery correlated negatively (r= -0.49, p=0.04), whereas the RI correlated positively (r=0.53, p=0.02) with testosterone levels in the premenopausal group. Postmenopausal women with higher testosterone levels had lower EDV (r= -0.53, p=0.007) in the central retinal artery and higher RI in both vessels (ophthalmic artery r=0.48, p=0.01; central retinal artery r=0.61, p=0.002).

CONCLUSION

Our data provide evidence of a relationship between serum sex hormone levels and blood flow velocities and resistive indices in retrobulbar arteries. Oestradiol appears to have beneficial effects on ocular haemodynamics, whereas testosterone may act as an antagonistic to the effects of oestrogen.

Influence of serum levels of sex hormones on intraocular pressure in menopausal women

PURPOSE

The purpose of this study was to assess the effect that changes in sex hormone levels have on intraocular pressure (IOP) in menopausal women.

SUBJECTS AND METHODS

Thirty menopausal women on hormone replacement therapy and 32 menopausal women who had never received hormone replacement therapy (HRT), matched for age and duration of amenorrhea, participated in this study. Intraocular pressures were measured with Goldmann applanation tonometer. Serum levels were measured for estradiol, free testosterone, and follicle stimulating hormone (FSH). The influence of serum hormone levels on IOP was assessed by correlation analysis.

RESULTS

The mean IOP of postmenopausal women receiving HRT (13.29 +/- 2.28 mm Hg) was not significantly different from that of menopausal women not receiving HRT (13.56 +/- 2.5 mm Hg, P = 0.24). Higher testosterone levels were associated with higher IOPs in women receiving HRT (r = 0.48, P = 0.02) and in those not receiving HRT (r =0.42, P = 0.003). No significant correlations were observed between IOP and serum levels of estradiol and FSH in either group.

CONCLUSION

Our data provide evidence for a relation between serum testosterone levels and IOP in menopause. Higher testosterone seems to have a tendency to increase IOP in menopausal women.

The role of gender in the progression of renal disease

The rate of progression of certain renal diseases in animals is greater in men than in women. In various animal models of renal disease, investigators have concluded that the presence of testosterone explains the worse course in men compared with women, whereas in other diseases, estrogen seems to confer protection for women. The gender disparity in renal disease progression found in animals is seen in certain human renal diseases, including chronic renal disease, membranous nephropathy, immunoglobin A nephropathy, and polycystic kidney disease. In humans, the differences between the genders in renal disease progression cannot be fully explained by differences in blood pressure or serum cholesterol levels. The underlying mechanisms for this gender disparity are potentially related to differences between the sexes in glomerular structure, glomerular hemodynamics, diet, variations in the production and activity of local cytokines and hormones, and/or the direct effect of sex hormones on kidney cells. Further investigation into the contribution of gender to renal disease progression may aid us in developing strategies for slowing this pathological process.

Minireview: estrogen and mouse models of atherosclerosis

The use of hormone replacement therapy for coronary heart disease prevention in humans has been an area of intense controversy. The atheroprotective qualities of estrogens have been challenged recently by several negative results of randomized clinical trials in postmenopausal women. However, the inhibitory effects of estrogens on atherogenesis are well documented in numerous animals, including atherosclerotic mouse models, but the detailed mechanisms of this protection are not understood. In this minireview, we will focus on the considerable success that has been achieved in demonstrating the atheroprotective effects of 17beta-estradiol in apolipoprotein E and low-density lipoprotein receptor-deficient mice and the use of these atherosclerotic mouse models in pharmacological and genetic study designs to investigate antiatherogenic mechanisms of estrogens. Mouse models of atherosclerosis should prove beneficial to understanding the cellular and molecular mechanisms of estrogen-mediated atheroprotection and aid the development of improved therapies to confer the benefits and reduce the risks associated with hormone replacement therapy.

Pulsatile ocular blood flow during pregnancy

PURPOSE

To study pulsatile ocular blood flow (POBF) throughout pregnancy.

METHODS

We enrolled twenty-seven healthy women in the first trimester of gestation, only ten of which were followed through the second trimester, and fourteen non pregnant healthy women. In each subject we measured POBF with the POBF pneumotonometer (OBF Ltd. UK), IOP, blood pressure (BP) and heart rate (HR). An unpaired Student t-test was used to compare pregnant women with non-pregnant women, and a two-tailed paired Student t-test was used to compare the same women in the first and second trimester of pregnancy. p <0.05 is considered statistically significant.

RESULTS

Results are presented as means +/- SD. In the first trimester of pregnancy the age was 32 +/- 6, POBF 1516.4 +/- 382 ml/min, IOP 13 +/- 3 mmHg, BP 92 +/- 6 mmHg, and HR 86 +/- 14 beats/min. In the second trimester POBF was 1629.11 +/- 352.4 ml/min, intraocular pressure (IOP) 12 +/- 3 mmHg, BP 96 +/- 3 mmHg, and HR 93 +/- 10 beats/min. In the control group the age was 27 +/- 9, POBF 972.23 +/- 329.3 ml/min, BP 88 +/- 4.3 mmHg, and HR 80 +/- 14 beats/min. POBF increases during the first trimester (p = 0.00008). In the second trimester POBF was higher compared to the first trimester (p = 0.0008). Non significant differences were observed for the other parameters.

CONCLUSIONS

The POBF increases throughout gestation. During pregnancy there is an increase in estrogen which induces endothelial-dependent vasodilatation in several tissues. The estrogen changes may influence POBF.

Estrogen receptor-alpha mediates the protective effects of estrogen against vascular injury

Blood vessel cells express the 2 known estrogen receptors, alpha and beta (ERalpha, ERbeta), which are thought to mediate estrogen inhibition of vascular injury and atherosclerosis, but the relative role of ERalpha and ERbeta in these events is controversial. Estrogen inhibits the vascular injury response to the same extent in ovariectomized female wild-type mice and in the original single gene knockout mice for ERalpha (ERalphaKO(Chapel Hill) [ERalphaKO(CH)]) and ERbeta (ERbetaKO(Chapel Hill) [ERbetaKO(CH)]). In double gene knockout mice generated by crossing these animals (ERalpha,betaKO(CH)), estrogen no longer inhibits medial thickening after vascular injury, but still inhibits vascular smooth muscle cell proliferation and increases uterine weight. The partial retention of estrogen responsiveness in ERalpha,betaKO(CH) mice could be due either to the presence of a novel, unidentified estrogen receptor or to functional expression of an estrogen receptor-alpha splice variant in the parental ERalphaKO(CH) mice. To distinguish between these possibilities, we studied recently generated mice fully null for estrogen receptor alpha (ERalphaKO(Strasbourg) [ERalphaKO(St)]) and examined the effect of estrogen on the response to vascular injury. In the present study, we show that after vascular injury in ovariectomized ERalphaKO(St) mice, estrogen has no detectable effect on any measure of vascular injury, including medial area, proteoglycan deposition, or smooth muscle cell proliferation. These data demonstrate that estrogen receptor-alpha mediates the protective effects of estrogen on the response to vascular injury.

Hormone replacement therapy with estradiol valerate and cyproterone acetate: effects on endothelium-dependent vasodilatation and arterial wall compliance

OBJECTIVE

to evaluate changes in vasomotor endothelium function and elastic properties of the brachial artery in postmenopausal women beginning hormone replacement therapy (HRT) with Climen(R), a 28-day sequential therapy combining estradiol valerate (E2V) 2 mg/day D1-D21 with cyproterone acetate (CPA) 1 mg/day D12-D22, followed by a 7-day treatment-free interval.

METHODS

Thirty-one women with natural or surgical menopause were included in an open multicenter study. Before treatment, at the end of the estrogen-only phase of cycle 1, and after the combined phase in cycles 1 and 3, endothelium-dependent vasodilatation (EDVD%) in the brachial artery was measured by the post-ischemia increase of the inner diameter, and pulse wave velocity (PWV) was measured in the same artery by simultaneous continuous wave Doppler and photo-plethysmography.

RESULTS

compared to pre-treatment values, the median increase in EDVD was 14.3% after cycle 1 (P=0.0001) and 27.9% after cycle 3 (P=0.0001). CPA did not alter the effect of E2V on EDVD in cycle 1. Median arterial systolic pressure was unchanged, but median diastolic pressure fell from 70 to 67.5 mmHg (P=0.04) after cycle 3. Median PWV was reduced by 0.76 m/s after cycle 3 (relative reduction -9.3%) (P=0.035). There was a significant correlation between PWV and EDVD changes from pre-treatment values at the end of the 3rd cycle.

CONCLUSION

treatment of postmenopausal women with E2V/CPA led to an immediate and significant improvement in endothelium-dependent vasodilatation. The estrogen-related vasomotor effect was not suppressed by the progestogen CPA. The WV changes are consistent with slower improvement of arterial compliance in some women. The non-invasive measurement of EDVD and PWV is a convenient method for the evaluation of both mechanical and functional effects of combination HRT on the arterial wall.

Effects of transdermal hormone replacement therapy on levels of soluble P- and E-selectin in postmenopausal healthy women

OBJECTIVE

To study the adhesion molecule pattern in postmenopausal women who were not receiving hormone replacement therapy (HRT), HRT users, and fertile women.

DESIGN

Case-control study.

SETTING

Second University of Naples, Naples, Italy.

PATIENT(S)

Fifty healthy naturally postmenopausal women and 20 fertile women.

INTERVENTION(S)

Twenty-six women received no HRT and 24 received continuous transdermal 17 beta-estradiol, 0.05 mg/d, plus oral acetate nomegestrol, 5 mg/d.

MAIN OUTCOME MEASURE(S)

Levels of the soluble forms of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and P-selectin.

RESULT(S)

Women who did not received HRT showed a trend toward higher levels of soluble E-selectin and had significantly higher levels of soluble P-selectin than did fertile women. Levels of soluble E-selectin and soluble P-selectin were significantly lower in HRT users than in nonusers. Levels of VCAM-1 levels were significantly higher in HRT users than in fertile women, but no significant differences in CAM concentrations were found between the other groups.

CONCLUSION(S)

Menopause may lead to increased levels of soluble E- and soluble P-selectin, whereas long-term HRT is associated with lower selectin concentrations. This suggests that HRT may have a beneficial effect on endothelial function.

Essential role for estrogen in protection against Vibrio vulnificus-induced endotoxic shock

Little is known about the underlying mechanisms that result in a sexually dimorphic response to Vibrio vulnificus endotoxic shock. V. vulnificus is a gram-negative bacterium, considered one of the most invasive and rapidly fatal human pathogens known. However, 85% of individuals that develop endotoxic shock from V. vulnificus are males. Using the rat, we have developed a model for V. vulnificus endotoxic shock that mimics the sexually dimorphic response in humans. Gonadectomy in females results in increased mortality, and estrogen replacement results in decreased mortality in both gonadectomized males and females. These results demonstrate that estrogen is providing protection against V. vulnificus lipopolysaccharide-induced endotoxic shock.

Hormone replacement therapy: primary and secondary prevention

Researchers are far from understanding the mechanism(s) of action of hormone replacement therapy (HRT) on the cardiovascular system. Moreover, the results of clinical trials that can clarify these dilemmas will not be available for several years. As clients seek guidance in making the pivotal decision about taking HRT, it is important that practitioners understand what the current research reveals about its risks and benefits. This article addresses the role of HRT in primary and secondary prevention and includes observational research, clinical trials (completed and in progress), benefits and risks, and implications for clinical practice in counseling patients.

Association of circulating cellular adhesion molecules with menopausal status and hormone replacement therapy. Time-dependent change in transdermal, but not oral estrogen users

The incidence of coronary heart disease is lower in premenopausal than in postmenopausal women, and estrogen use may be cardioprotective among postmenopausal women. Cellular adhesion molecules (CAM) are involved in the early stage of atherosclerosis, and short-term administration of oral estrogen decreased plasma concentrations of their soluble forms in postmenopausal women. However, data evaluating transdermal estrogen are sparse and long-term effect of hormone replacement therapy (HRT) on CAM is unknown. Therefore, we have investigated the association of circulating CAM (cCAM) with menopausal status and long-term HRT. Plasma levels of intercellular adhesion molecule-1 (cICAM-1), vascular cell adhesion molecule-1 (cVCAM-1), P-selectin, E-selectin, C-reactive protein (CRP), and fibrinogen were measured in 74 premenopausal women, 60 postmenopausal women not using HRT, 30 postmenopausal women using opposed oral estrogen therapy, and 30 postmenopausal women using opposed transdermal estrogen therapy. All women were apparently healthy and aged between 45 and 54 years. Duration of HRT ranged from 3 to 96 months. Postmenopausal women not receiving HRT had 24% higher mean levels of cICAM-1 than premenopausal women (318 vs. 255 ng/ml, P < .001). In postmenopausal women, users of oral estrogen had 16% lower, and users of transdermal estrogen had 17% lower mean levels of cICAM-1 than non-users (268 and 264 vs. 318 ng/ml, P = .001 for both comparisons). Furthermore, in users of transdermal route, the lowering effect of estrogen on cICAM-1 was dependent on treatment duration, while no time-dependent effect was seen in oral estrogen users. Users of transdermal estrogen had lower cVCAM-1 and P-selectin levels than postmenopausal non-users (327 vs. 364 ng/ml (P = .05) and 18 vs. 23 ng/ml (P = .05). There was no difference in CRP and E-selectin levels between the groups. Adjustment for age and body mass index (BMI) made no substantial change in the results. These data suggest that oral and transdermal estrogen may play a long-term cardioprotective role through favourable changes in endothelial function.

Estrogen receptor transcription and transactivation: Basic aspects of estrogen action

Estrogen signaling has turned out to be much more complex and exciting than previously thought; the paradigm shift in our understanding of estrogen action came in 1996, when the presence of a new estrogen receptor (ER), ERbeta, was reported. An intricate interplay between the classical ERalpha and the novel ERbeta is of paramount importance for the final biological effect of estrogen in different target cells.

Estrogen-replacement therapy: effects on retrobulbar hemodynamics

PURPOSE

Estrogen-replacement therapy causes vasodilation and increased blood flow in major peripheral arteries. We examined the role that estrogen may play in enhancing perfusion within the watersheds of several major and minor retrobulbar arteries.

METHODS

Postmenopausal women receiving estrogen-replacement therapy (n = 16) were compared with both age-matched women not receiving estrogen (n = 16) and with young women (n = 20). Studies involved color Doppler imaging analysis of flow velocities measured in the ophthalmic, central retinal, and nasal and temporal posterior ciliary arteries.

RESULTS

In the ophthalmic artery, young women and postmenopausal women receiving estrogen exhibited reduced resistance indexes as compared with postmenopausal women not receiving estrogen (each P <. 001). In contrast, flow velocities in the central retinal artery were similar among the three groups of women. In the posterior ciliary arteries, a different pattern emerged: young women, as compared with either group of postmenopausal women, showed greater peak systolic and end-diastolic velocities at similar resistance index (each P <.05).

CONCLUSIONS

Estrogen-replacement therapy in postmenopausal women apparently helps reduce vascular resistance distal to the ophthalmic artery to levels matching those of young women. However, estrogen replacement has little impact on flow velocities in the posterior ciliary arteries. In those vessels, aging per se may reduce perfusion, potentially contributing to the age-dependent risk of major eye diseases, such as glaucoma and age-related macular degeneration.

The estrogen receptor family

A significant flow of new data is currently being generated within the field of estrogen receptors and their mechanisms of action. This is primarily a result of the development of estrogen receptor knockout mice and the discovery of the second estrogen receptor, estrogen receptor beta. Both estrogen receptors appear to be involved in a multitude of regulatory events, the details of which will be worked out within the next few years. Estrogen receptor alpha appears to play a major role in the regulation of reproductive events and estrogen receptor alpha knockout female mice are completely infertile. Estrogen receptor beta knockout females have severe but incomplete infertility. Estrogen receptor beta gene mutations may, therefore, be of great clinical interest because they could perhaps explain some cases in which ovarian dysfunction leads to human infertility. Both receptors appear to be of essence for the cardiovascular system. Future studies will determine the relative importance of estrogen receptors alpha and beta in bone, the urogenital tract, the immune system, and the central nervous system, as well as in other estrogen target tissues.

Long-term effects of combined hormone replacement therapy on markers of endothelial function and inflammatory activity in healthy postmenopausal women

OBJECTIVE

To study the effects of combined hormone replacement therapy on markers of endothelial function and inflammatory activity.

DESIGN

Prospective, randomized, controlled study.

SETTING

Academic hospital.

PATIENT(S)

Healthy postmenopausal women with an intact uterus.

INTERVENTION(S)

For the first 12 months, the hormone replacement therapy group (n = 14) received oral E2, 1 mg daily, sequentially combined with 5 or 10 mg of dydrogesterone. Thereafter, they received oral E2, 2 mg daily, sequentially combined with 10 mg of dydrogesterone. The control group (n = 13) received no treatment. Data were collected at baseline and at 3, 12, and 15 months.

MAIN OUTCOME MEASURE(S)

Parameters of endothelial function and inflammatory activity.

RESULT(S)

During 12 months of follow-up, we observed decreases of 15% in plasma levels of endothelin-l, of 21% in soluble thrombomodulin, of 14% in von Willebrand factor, and of 12% in clottable fibrinogen in the hormone replacement therapy group compared with the control group. There was a 5% decrease in soluble E-selectin tevels. All significant changes were observed by 3 months and sustained after 15 months. Brachial artery flow-mediated vasodilatation and C-reactive protein levels did not change significantly.

CONCLUSION(S)

Long-term combined hormone replacement therapy with E2 and dydrogesterone in healthy women was associated with sustained improvement in some aspects of endothelial function and in clottable fibrinogen levels.