Hormone replacement therapy reduces the reactivity of monocytes and platelets in whole blood--a beneficial effect on atherogenesis and thrombus formation?

High-dose oral contraceptives induce hyperinsulinemia without altering immune activation in diet-induced obesity which persists even following a dietary low-fat diet intervention

Combined oral contraceptives (COCs) are known to cause weight gain and alter metabolic and immunological pathways. However, modifications in arterial or venous thrombotic risk profiles of women of reproductive ages on COC remain unclear. The study aimed at assessing the impact of COC on immune activation in diet-induced obesity. We further established whether the dietary intervention of switching from a high-fat diet (HFD) to a low-fat diet (LFD) attenuates immunological responses. Twenty (n=20) five-week-old female Sprague Dawley rats were randomly divided into two diet groups of HFD (n=15) and LFD (n=5) and were monitored for eight weeks. After eight weeks, animals in the HFD group switched diets to LFD and were randomly assigned to receive high-dose COC (HCOC) or low-dose COC (LCOC) for six weeks. Animals on HFD significantly gained weight and had a higher lee index when compared to the LFD group (p < 0.05). Moreover, the triglyceride-glucose index, insulin, and other metabolic parameters also increased in the HFD group compared to the LFD group (p < 0.001). Consistently, the levels of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α), were elevated in the HFD group when compared to the LFD group (p < 0.05). Upon switching from a high-fat to a low-fat diet, insulin levels persistently increased in animals receiving HCOC treatment compared to the LFD and HFD/LFD groups (p < 0.05). Thus, in a rat model of HFD-feeding, short-term HCOC treatment induces long-term metabolic dysregulation, which persists despite dietary intervention. However, further studies are recommended to confirm these findings.

Hormone Replacement Therapy and Psoriasis Risk: A Nationwide Population-Based Cohort Study

BACKGROUND

Hormone replacement therapy (HRT) is used to relieve menopause symptoms, but has been reported to be associated with coronary heart disease and cancers in women. However, a link between HRT and psoriasis has yet to be established. The aim of this study was to determine the association between HRT and the risk of psoriasis.

METHODS

We executed a nationwide population-based study. A total of 1,130,741 post-menopause women were enrolled in the national health care insurance database based on the enrollment criteria. The study population was classified into four groups based on the duration of the HRT, and the risk of psoriasis was analyzed.

RESULTS

The incidence rates of psoriasis per 1,000 person-years were 3.36 and 4.09 in the no history of HRT and ≥ 5 years of HRT, respectively. After adjustment for age, smoking, alcohol intake, regular exercise, body mass index, diabetes mellitus, hypertension, and dyslipidemia, the most prolonged duration of the HRT group (≥ 5 years) exhibited significantly increased risk of developing psoriasis (hazard ratio, 1.22; 95% confidence interval, 1.16-1.29).

CONCLUSION

We propose that HRT in post-menopausal women is associated with an increased likelihood of psoriasis development.

Estetrol Is Safe and Well Tolerated during Treatment of Hospitalized Men and Women with Moderate COVID-19 in a Randomized, Double-Blind Study

Epidemiological data suggest that the severe acute respiratory syndrome coronavirus 2 infection rate is higher in women than in men, but the death rate is lower, while women (>50 years) on menopausal hormone therapy (MHT) have a higher survival rate than those not on MHT. Classical oral estrogen enhances the synthesis of coagulation markers and may increase the risk of thromboembolic events that are common in coronavirus disease 2019 (COVID-19). The favorable hemostatic profile of estetrol (E4) might be suitable for use in women who are receiving estrogen treatment and contract COVID-19. A multicenter, randomized, double-blind, placebo-controlled, phase 2 study (NCT04801836) investigated the efficacy, safety, and tolerability of E4 versus placebo in hospitalized patients with moderate COVID-19. Eligible postmenopausal women and men (aged ≥ 18 years old) were randomized to E4 15 mg or placebo, once daily for 21 days, in addition to the standard of care (SoC). The primary efficacy endpoint of improvement in COVID-19 (percentage of patients recovered at day 28) between the placebo and E4 arms was not met. E4 was well tolerated, with no safety signals or thromboembolic events, suggesting that postmenopausal women can safely continue E4-based therapy in cases of moderate COVID-19 managed with SoC.

Estradiol, Progesterone, Immunomodulation, and COVID-19 Outcomes

Severe outcomes and death from the novel coronavirus disease 2019 (COVID-19) appear to be characterized by an exaggerated immune response with hypercytokinemia leading to inflammatory infiltration of the lungs and acute respiratory distress syndrome. Risk of severe COVID-19 outcomes is consistently lower in women than men worldwide, suggesting that female biological sex is instrumental in protection. This mini-review discusses the immunomodulatory and anti-inflammatory actions of high physiological concentrations of the steroids 17β-estradiol (E2) and progesterone (P4). We review how E2 and P4 favor a state of decreased innate immune inflammatory response while enhancing immune tolerance and antibody production. We discuss how the combination of E2 and P4 may improve the immune dysregulation that leads to the COVID-19 cytokine storm. It is intended to stimulate novel consideration of the biological forces that are protective in women compared to men, and to therapeutically harness these factors to mitigate COVID-19 morbidity and mortality.

Effects of Estrogens on Platelets and Megakaryocytes

In women, oral menopausal hormonal therapy (MHT) is associated with adverse effects including an increased incidence of thromboembolic events, classically attributed to an increase in several liver-derived coagulation factors due to hepatic first pass. While platelets are central players in thrombus constitution, their implication in women treated with estrogens remains incompletely characterized. Platelets and their medullar progenitors, megakaryocytes, express estrogen receptors (ER) that may explain, at least in part, a sensitivity to hormonal changes. The purpose of this review is to summarize our current knowledge of estrogen actions on platelets and megakaryocytes in mice following in vivo administration and in women using MHT.

How sex and age affect immune responses, susceptibility to infections, and response to vaccination

Do men die young and sick, or do women live long and healthy? By trying to explain the sexual dimorphism in life expectancy, both biological and environmental aspects are presently being addressed. Besides age-related changes, both the immune and the endocrine system exhibit significant sex-specific differences. This review deals with the aging immune system and its interplay with sex steroid hormones. Together, they impact on the etiopathology of many infectious diseases, which are still the major causes of morbidity and mortality in people at old age. Among men, susceptibilities toward many infectious diseases and the corresponding mortality rates are higher. Responses to various types of vaccination are often higher among women thereby also mounting stronger humoral responses. Women appear immune-privileged. The major sex steroid hormones exhibit opposing effects on cells of both the adaptive and the innate immune system: estradiol being mainly enhancing, testosterone by and large suppressive. However, levels of sex hormones change with age. At menopause transition, dropping estradiol potentially enhances immunosenescence effects posing postmenopausal women at additional, yet specific risks. Conclusively during aging, interventions, which distinctively consider the changing level of individual hormones, shall provide potent options in maintaining optimal immune functions.

Coronary Heart Disease in Postmenopausal Women with Type II Diabetes Mellitus and the Impact of Estrogen Replacement Therapy: A Narrative Review

Coronary heart disease is the main cause of death in postmenopausal women (PMW); moreover its mortality exceeds those for breast cancer in women at all ages. Type II diabetes mellitus is a major cardiovascular risk factor and there is some evidence that the risk conferred by diabetes is greater in women than in men. It was established that the deficiency of endogenous estrogens promotes the atherosclerosis process. However, the impact of estrogen replacement therapy (ERT) on cardiovascular prevention remains controversial. Some authors strongly recommend it, whereas others revealed a concerning trend toward harm. This review tries to underlines the different components of cardiovascular risk in diabetic PMW and to define the place of ERT.

Combination of caregiving stress and hormone replacement therapy is associated with prolonged platelet activation to acute stress among postmenopausal women

OBJECTIVE

To investigate the combined effects of caregiving and hormone replacement therapy (HRT) on platelet hyperactivity to acute psychological stress. Both HRT and the chronic stress of caregiving have been associated with increased cardiovascular risk, potentially through a mechanism of platelet hyperactivity.

METHODS

A total of 78 elderly postmenopausal women (51 caregivers (CG) and 27 noncaregivers (NC)) were assessed for platelet activation in response to a laboratory speech test. Half the sample was taking HRT. Blood was sampled at baseline, post speech, and after 14 minutes of recovery. Platelet activation was assessed through whole blood flow cytometry assays of % aggregates (Agg), and expression of % fibrinogen receptors (FbR) and % P-selectin (P-sel) on platelet surface.

RESULTS

Multivariate repeated-measures analysis of variance revealed that CG taking HRT exhibited significantly prolonged platelet activation in response to acute stress. There was an interaction between HRT and CG on recovery from stress for Agg (F (1,71) = 5.260, p = .025), P-Sel (F(1,71 = 6.426, p = .013), and FbR (F(1,71 = 6.653, p = .012), controlling for age, cardiovascular disease, and aspirin. Among HRT users, regression analysis revealed that CG had delayed recovery of Agg (beta = 0.354, t(34) = 2.154, p = .038) and P-sel (beta = 0.498, t(34)=3.126, p = .004) from stress relative to NC. No caregiving effects on recovery were present among non-HRT users. In addition, these effects were maintained after controlling for health behaviors, medications, and medical conditions.

CONCLUSION

Chronic dementia caregiving stress in combination with HRT may impair recovery of platelet activation after acute mental stress (i.e., activation levels do not quickly return to resting levels), thereby potentially increasing cardiovascular risk among CG who take HRT.

The complex role of estrogens in inflammation

There is still an unresolved paradox with respect to the immunomodulating role of estrogens. On one side, we recognize inhibition of bone resorption and suppression of inflammation in several animal models of chronic inflammatory diseases. On the other hand, we realize the immunosupportive role of estrogens in trauma/sepsis and the proinflammatory effects in some chronic autoimmune diseases in humans. This review examines possible causes for this paradox. This review delineates how the effects of estrogens are dependent on criteria such as: 1) the immune stimulus (foreign antigens or autoantigens) and subsequent antigen-specific immune responses (e.g., T cell inhibited by estrogens vs. activation of B cell); 2) the cell types involved during different phases of the disease; 3) the target organ with its specific microenvironment; 4) timing of 17beta-estradiol administration in relation to the disease course (and the reproductive status of a woman); 5) the concentration of estrogens; 6) the variability in expression of estrogen receptor alpha and beta depending on the microenvironment and the cell type; and 7) intracellular metabolism of estrogens leading to important biologically active metabolites with quite different anti- and proinflammatory function. Also mentioned are systemic supersystems such as the hypothalamic-pituitary-adrenal axis, the sensory nervous system, and the sympathetic nervous system and how they are influenced by estrogens. This review reinforces the concept that estrogens have antiinflammatory but also proinflammatory roles depending on above-mentioned criteria. It also explains that a uniform concept as to the action of estrogens cannot be found for all inflammatory diseases due to the enormous variable responses of immune and repair systems.

Benefit and safety of 28-day transdermal estrogen regiment during vaginal hysterectomy (a controlled trial)

OBJECTIVES

Assessment of benefit and safety of 28-day transdermal 17-beta estradiol regimen during vaginal hysterectomy.

METHODS

Two-hundred and sixty-nine postmenopausal women, undergoing vaginal hysterectomy were divided into: transdermal estrogen hormone replacement therapy (TEHRT) group (n=119) with 28-day transdermal 17-beta estradiol 50 mg/day, 14 days before and after operation; and vaginal estrogen hormone replacement therapy (VEHRT) group (n=150) with 14-day preoperative vaginal conjugated estrogen 0.625 mg/day. The effect on: endometrium, wound healing, infection, recurrent organ prolapse were evaluated.

RESULTS

Pain symptoms, vaginal fetid discharge, swelling, crusting (p<0.001); visible wound opening on the 4 week control (p<0.01); patient assessment of outcome (p<0.001) were in favor of TEHRT. On the fifth postoperative day, VEHRT group showed: higher leukocytes increase (p<0.01); more patients with leukocytes count higher than 15x10(9) L(-1) (p<0.001) and afternoon body temperature higher than 38 degrees C (p<0.01). On the last follow-up control (VEHRT--28.3 months and TEHRT--24.5 months) TEHRT group had more patients with stage 0 of the apical segment (p<0.05). Point C was higher and total vaginal length longer in TEHRT group (p<0.01; p<0.05). Frequency, constipation, painful coitus, incontinence during intercourse were more frequent in VEHRT (p<0.001; p<0.05; p<0.05; p<0.05). Endometrium with a thickness between 2 and 4 mm, was more frequent in the TEHRT group (p<0.05). There were no significant differences in occurrence of more thickened endometrium and more significant morphological changes (endometrial polyp, simplex hyperplasia) between the groups. In none of the patients from the both study groups complex hyperplasia, atypical hyperplasia or endometrial carcinoma were observed.

CONCLUSIONS

The 28-day transdermal 17-beta estradiol regimen seems to be safe and effective procedure.

Systematic review: Hormone therapy and cardiovascular disease: a systematic review and meta-analysis

BACKGROUND

Despite decades of evidence from observational studies, the use of hormone therapy for the prevention of cardiovascular disease (CVD) among postmenopausal women is controversial. The recent completion of several randomised clinical trials examining the effects of hormone therapy on CVD presents an opportunity to provide a more precise estimate of the cardiovascular risks of hormone therapy.

OBJECTIVE

To summarise the effects of hormone therapy on CVD in postmenopausal women.

SEARCH STRATEGY

MEDLINE, EMBASE, the Cochrane Library, DARE and CENTRAL were searched for clinical trials reporting mortality and/or CVD outcomes in association with hormone therapy. Bibliographies and editorials were also reviewed. All studies were reviewed and rated for quality independently by two reviewers.

SELECTION CRITERIA

High quality, randomised placebo-controlled clinical trials of hormone therapy (duration greater than one year) in non-hospitalised postmenopausal women were included.

DATA COLLECTION AND ANALYSIS

Summary relative risks were estimated for all-cause mortality, coronary heart disease (CHD) mortality, non-fatal acute myocardial infarction (AMI) and all stroke.

MAIN RESULTS

Seven randomised clinical trials met the inclusion criteria. The use of hormone therapy had no significant effect on all-cause mortality, non-fatal AMI or CHD mortality, with relative risks of 1.02 [95% confidence interval (CI) 0.93-1.13], 1.00 (0.88-1.14) and 0.99 (0.82-1.21), respectively. For all stroke, the summary relative risk was 1.29 (1.13-1.48).

AUTHOR'S CONCLUSIONS

This systematic review, incorporating the latest available trial data, shows that hormone therapy does not significantly change the risk of all-cause morality, CHD death or non-fatal AMI but increases the risk of stroke in postmenopausal women.

Effect of menopause on platelet activation markers determined by flow cytometry

Pre-menopausal women have a lower risk of cardiovascular disease compared to post-menopausal women. Cardiovascular disease is more age dependent in women than in men. The association of platelet activation and cardiovascular thrombotic events is well established. Standardized techniques were used to evaluate platelet activation markers by flow cytometry, using 3-color analysis (CD 61PerCP, CD 62P, and PAC-1) in 49 post-menopausal (mean +/- SD age, 56.16 +/- 33.51 years) and 42 pre-menopausal (age, 39.38 +/- 7.07 years) women. Results of our study showed a significant increase in CD 62P in post-menopausal women as compared to the pre-menopausal group (2.66 +/- 4.26% vs. 0.52 +/- 2.71%, P < 0.001). Similarly, PAC-1 was significantly increased in post-menopausal women (21.54 +/- 2.48% vs. 3.70 +/- 2.31%, P < 0.001). Furthermore, there was a significant association of CD 62P with serum estradiol in both groups. PAC-1 was significantly associated with age in both groups. The results suggest the role of platelets in the increased incidence of thrombotic events and disease in post-menopausal women.

Effects of estrogen on platelet reactivity after transient forebrain ischemia in rats

Estrogen's prothrombotic effects are of increasing concern, particularly in stroke risk and recovery. Using an ischemic rodent model, the authors sought to determine (a) if estrogen replacement increases postischemic platelet reactivity, (b) if changes in estrogen status alter intraplatelet endothelial nitric oxide synthase (eNOS) synthesis, and (c) if estrogen-mediated effects on platelets alter cerebral blood flow during reperfusion. Intact (I), ovariectomized (OVX), and OVX + 17 beta-estradiol (E50) rats were subjected to 30 min of forebrain ischemia and 60 min of reperfusion. Using the platelet activation marker P-selectin, postischemic platelet reactivity was quantified by flow cytometry. In a separate cohort (I, OVX, E50), the authors quantified platelet eNOS by Western blot. Another cohort (OVX, E50) was subjected to ischemia/reperfusion, and cerebral blood flow was determined using the iodoantipyrine technique. Collagen-stimulated platelet P-selectin expression was increased in the OVX rats at 60 min of reperfusion, and this effect was reversed by estrogen treatment. No differences in platelet eNOS expression were detected among groups. Cerebral blood flow at 60 min reperfusion was comparable between the OVX and the E50 rats. The authors conclude that during reper-fusion, estrogen deficiency increases postischemic platelet sensitivity to stimuli in estrogen-deficient rats. Estrogen treatment mitigates effects of estrogen loss on platelets, but this early effect is apparently not caused by intraplatelet eNOS depression. Neither estrogen deficiency nor estrogen treatment changes early postischemic regional brain blood flow. In this rodent global cerebral ischemic model, physiologic doses of estrogen are not deleterious to platelet reactivity and may initially reduce postischemic platelet reactivity.

Long-term hormone replacement therapy does not cause increased platelet activation

BACKGROUND

Observational studies have shown apparently lower ischemic coronary disease risk in postmenopausal women receiving hormone replacement therapy (HRT). However, several recent studies have shown an increase in ischemic cardiac events when HRT is initiated in postmenopausal women with known coronary artery disease. It is postulated that estrogen may result in increased platelet aggregation.

METHODS

We evaluated platelet activation, as measured by flow cytometric analysis using P selectin and PAC1 as activation markers, and aggregation, as measured by standard platelet aggregation using platelet-rich plasma, in 27 postmenopausal women (17 HRT, 10 placebo) who were participants in 2 placebo-controlled randomized angiographic trials evaluating the effect of HRT on coronary atherosclerosis or saphenous vein graft disease. All women had received HRT or placebo for >2 years and were on aspirin therapy. The estrogen component was either conjugated equine estrogen or 17beta-estradiol.

RESULTS

Patients on HRT and those on placebo had comparable degrees of platelet aggregation when measured using various doses of agonists (adenosine diphosphate and epinephrine). There were no significant differences in levels of platelet activation measured by flow cytometry.

CONCLUSION

We conclude that long-term HRT does not appear to cause increased platelet activation and aggregation in women with coronary artery disease. There may be increased platelet activation in the early period after HRT initiation; however, this was not assessed in this study.

Estrogenic regulation of tissue factor and tissue factor pathway inhibitor in platelets

Oral estrogen treatment increases thrombotic risk. Tissue factor (TF), tissue factor pathway inhibitor (TFPI), and platelet interaction with leukocytes are important determinants of thrombogenesis. Therefore, the present study was designed to define and compare platelet TF and TFPI mRNA and adhesion protein expression in platelets derived from animals treated with different types of oral estrogens. Ovariectomized pigs were treated with 17beta-estradiol (2 mg/day), conjugated equine estrogen (CEE; 0.625 mg/day), or raloxifene (60 mg/day) for 4 wk. Compared with intact animals, ovariectomy and treatment differentially affected populations of leukocytes: neutrophils decreased whereas lymphocytes increased significantly 4 wk after ovariectomy and with 17beta-estradiol and CEE treatments; eosinophils increased only with 17beta-estradiol treatment. Content of TF protein increased in platelets from 17beta-estradiol- and raloxifene-treated pigs, whereas TF mRNA was detected only in platelets from 17beta-estradiol- and CEE treated pigs. TFPI mRNA increased in platelets after ovariectomy and estrogen treatment. Only a trace of TFPI protein was detected, but a higher-molecular-mass protein was observed in all treatment groups. Expression of CD40 and CD40 ligand increased with ovariectomy and decreased with 17beta-estradiol and CEE treatments more than with raloxifene. The ratio of activated to basal P-selectin expression decreased with ovariectomy and increased with raloxifene treatments. These results suggest that estrogenic formulations may affect individual thrombotic risk by different mechanisms that regulate TF and platelet-leukocytic interactions. These studies provide the rationale for evaluation of interactions among platelets and TF and TFPI expression on thrombin generation during estrogen treatment in humans.

The effect of hormone replacement therapy on Ca2+ mobilization and P-selectin (CD62P) expression in platelets examined under flow cytometry

A series of events, such as increase of cytoplasmic free calcium (Ca2+) and expression of P-selectin (CD62P), an adhesion molecule, on the platelet surface, are significant indicators of platelet activation. We have used flow cytometry to examine Ca2+ mobilization and CD62P expression in platelets in whole blood obtained in women prior to, and after, different forms of hormone replacement therapy. Thirty-two women completed a protocol consisting of two consecutive 1-month periods under oestradiol (E2), administered orally (2 mg/day) or transdermally (50 microg/day) in random order, followed by a 4-week transdermal sequential regime, in which, during the last 14 days, either progesterone (300 mg/day) or medroxyprogesterone acetate (5 mg/day) was added to the 50 microg/day E2, administered orally in random order. None of the hormonal combinations determined significant changes in Ca2+ mobilization or CD62P expression in non-stimulated platelets. However, stimulation of platelets with adenosine diphosphate, but not with thrombin, caused a significant increase in cytoplasmic Ca2+ concentration during treatment with transdermal E2 plus progesterone. Also when stimulating with thrombin, transdermal E2 was more active than oral E2 in increasing CD62P expression, a difference that was not reduced by the addition of progestogens. In conclusion, hormone replacement therapy only increased Ca2+ mobilization or CD62P expression in stimulated platelets, and then followed a varied pattern that was dependent on the stimulant and on the specific hormonal formulation.

Tibolone, oral or transdermal hormone replacement and colour Doppler analysis

OBJECTIVE

To compare the plasma thromboxane, the plasma viscosity and the Doppler flow modifications induced by tibolone and by oral or transdermal continuous combined hormone replacement therapy.

METHODS

Forty-two post-menopausal patients underwent either on: oral daily treatment with tibolone (2.5 mg) (Group I; n= 14); or continuous oral administration of 0.625 mg conjugated equine estrogens + medroxyprogesterone 5 mg per day (Group II; n = 14 ); or continuous estradiol transdermal supplementation, at a dose of 50 microg per day, + medroxyprogesterone 5 mg per day (Group III; n = 14 ). The duration of the study was 6 months and the patients were submitted to transvaginal ultrasonographic evaluation of pelvic organs; Doppler analysis of the uterine, internal carotid and ophthalmic arteries; thromboxane and plasma viscosity assays in basal condition, and at 1, 3 and 6 months from the beginning of the study.

RESULTS

Although the endometrial thickness increased significantly, there were no cases in which it exceeded the normal range (< or = 5 mm). In all the three groups, the pulsatility index of the uterine, internal carotid and ophthalmic arteries significantly decreased during the therapy showing a reduced impedance since the first month of treatment. Similar variations were observed for the peak systolic blood flow velocity of the internal carotid and ophthalmic arteries. Hormone replacement therapy and tibolone induced a deep, significant and rapid decrease in plasma thromboxane and plasma viscosity levels.

CONCLUSIONS

Hormone replacement therapy and tibolone seem to have beneficial effects on vascular and hemorrheological parameters.

The role of estrogen in cardiovascular disease

Cardiovascular disease is the number one cause of death among women, accounting for nearly 50% of female deaths. Statistics show that women on average develop cardiovascular disease 10 to 15 years later in life than men, and that the risk may increase after menopause. This observation has led to much speculation as to what physiological change(s) associated with menopause is responsible for the higher risk of atherosclerosis. Estrogen, with its potential as a cardioprotective agent and as an immunomodulator of the inflammatory response in atherosclerosis, has received the most attention. Understanding the mechanisms that lead to these differences may allow beneficial therapeutic intervention to enhance this effect in females and evoke this protection in males. This review will do the following: (1) characterize mechanisms of atherosclerosis, (2) explore the role of estrogen-replacement therapy, (3) define the effect of gender on inflammation, (4) compare and contrast the effects of estrogen and testosterone on endothelial functional, and (5) suggest mechanistic based therapeutic opportunities.

Update on cardiovascular disease in post-menopausal women

Cardiovascular disease (CVD), and in particular coronary artery heart disease (CAHD), is the leading cause of morbidity and mortality in women. Until recently, most of our knowledge about the pathophysiology of CVD in women - and, subsequently, management guidelines - were based on studies conducted mostly in men. While similar mechanisms operate to induce CVD in women and men, gender-related differences exist in the anatomy and physiology of the myocardium, and sex hormones modify the course of disease in women. Women, more than men, have their initial manifestation of CAHD as angina pectoris; are likely to be referred for diagnostic tests at a more advanced stage of disease, and are less likely than men to have corrective invasive procedures. The overall morbidity and mortality following the initial ischaemic heart event is worse in women, and the case fatality rate is greater in women than in men. Also, the relative impact of impaired vasoreactivity of the coronary artery, increased viscosity of the blood and dysregulation of automaticity and arrhythmia, is greater in women than in men. The most effective means of decreasing the impact of CVD on women's health is by an active approach from childhood to proper principles of healthcare in order to modify the contribution of specific risk factors. The latter include obesity, abnormal plasma lipid profile, hypertension, diabetes mellitus, cigarette smoking, sedentary lifestyle, increased blood viscosity, augmented platelet aggregability, stress and autonomic imbalance. The use of lipid-lowering drugs has not been adequately studied in women but reports from studies conducted mostly in men do predict an advantage also to women. Oestrogen deficiency after spontaneous or medically induced menopause is an important risk factor for CVD and CAHD. Observational and mechanistic data suggest a role for oestrogen replacement after menopause for primary, and possibly secondary, prevention of CVD. However, two recent prospective trials suggest that treatment de novo with hormone replacement of older post-menopausal women after an acute coronary event may not confer cardiovascular protection and may increase the risk of thromboembolic disease. Results of ongoing long-term studies may determine the beneficial role of hormone replacement versus potential risks involved with this treatment.

The mechanisms of thrombotic risk induced by hormone replacement therapy

OBJECTIVES

To review the available information on the action of hormones on the mechanisms involved in thrombotic risk.

RESULTS AND CONCLUSIONS

Thrombosis plays a crucial role in the genesis and progression of both coronary heart disease (CHD) and venous thromboembolic disease (VTED), the two main forms of cardiovascular disease. Two main determinants of the thromboembolic phenotype, hypercoagulable state and altered endothelium, accumulate much of the work performed on the influence of hormones on thrombosis. Information has accumulated mainly for oestrogens, but increasing evidences support a role for progestogens. The sensitivity of each of the three components of the hemostatic balance, the coagulation cascade, the anticoagulant system and fibrinolysis, to oestrogens has been widely examined in the literature. Functional tests suggest that HRT is accompanied by a procoagulant state. Much of the work has concentrated on changes induced on reputable indicators of risk for either CHD or VTED. Distinct indicators of increased coagulability, such as resistance to activated C protein, antithrombin or tissue factor pathway inhibitor have been selected for VTED, whereas factor VII, fibrinogen, and defective fibrinolysis, for CHD. Different states of genetic susceptibility have been involved in both forms of the disease. The status of health of endothelium, defines another scenario for attention in CHD. A long-term anti-atherogenic action of oestrogens, which may be associated with short-term risk in cases of atherosclerosis-induced endothelial dysfunction, may most adequately explain much of the clinical observation. In both CHD and VTED, the procoagulant changes initiate soon after HRT administration.

Anti-inflammatory effects of 17beta-estradiol pretreatment in men after coronary artery surgery

OBJECTIVE

To investigate the anti-inflammatory and hemodynamic effects of 17beta-estradiol in men undergoing elective coronary artery bypass graft surgery (CABG).

DESIGN

Prospective, randomized, controlled.

SETTING

Operating room and intensive care unit in a university hospital.

PARTICIPANTS

Twenty-one men undergoing primary, elective CABG surgery.

INTERVENTION

17beta-estradiol, 2mg, was given orally twice in 14 hours before the operation.

MEASUREMENTS AND MAIN RESULTS

Leukocyte counts, plasma myeloperoxidase, tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, and IL-10 were measured perioperatively. Leukocyte counts were lower in the 17beta-estradiol group than in controls at 6 hours (11.4 +/- 2.0 hours v 15.5 +/- 4.7 hours x 10(9)/L) and 20 hours (11.6 +/- 1.9 hours v 13.6 +/- 2.5 hours x 10(9)/L) after reperfusion (p = 0.03). The release of myeloperoxidase was lower in the 17beta-estradiol group than in controls (5 minutes; 634.4 +/- 213.1 microg/mL v 773.1 +/- 209.3 microg/mL; 4 hours, 305.0 +/- 108.0 microg/mL v 441.3 +/- 191.6 microg/mL; p = 0.02). Systemic vascular resistance index was lower just after cardiopulmonary bypass, and cardiac index was higher postoperatively in the 17beta-estradiol group as compared with controls.

CONCLUSION

Pretreatment with 17beta-estradiol can limit leukocyte activation in men after CABG surgery.

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.

Interferon-gamma and lipopolysaccharide potentiate monocyte tissue factor induction by C-reactive protein: relationship with age, sex, and hormone replacement treatment

BACKGROUND

Elevated plasma levels of C-reactive protein (CRP) in population studies and in patients with unstable coronary syndromes are predictive of future adverse events, including cardiac death and myocardial infarction, implicating inflammation in pathogenesis. Although CRP is considered a marker of inflammation, it induces monocyte tissue factor (TF) and may play a prothrombotic role in atherosclerosis and its complications.

METHODS AND RESULTS

Peripheral blood mononuclear cells (PBMCs) from 79 healthy men and women aged 26 to 83 years and 21 healthy postmenopausal women taking hormone replacement therapy (HRT) were stimulated with CRP, lipopolysaccharide (LPS), interferon-gamma (IFN), or their combination. Levels of CRP in the normal range (1 to 5 microg/mL) increased basal monocyte TF 4- to 6-fold and 40-fold at higher concentrations (25 microg/mL). Coincubation of LPS with CRP produced a greater-than-additive response. IFN did not induce TF but synergized with CRP to approximately double activity. There was a striking positive correlation between age and monocyte TF induction, with a dramatic rise on monocytes from postmenopausal women that was not apparent on cells from women taking HRT.

CONCLUSIONS

Synergy between CRP and inflammatory mediators may play a direct prothrombotic role in the pathogenesis of coronary atherosclerosis and its acute complications by increasing monocyte/macrophage TF. This may contribute to age and sex differences in coronary events and to the protective effects of HRT.

Hormone replacement therapy in healthy postmenopausal women. Effects on intraplatelet cyclic guanosine monophosphate, plasma endothelin-1 and neopterin

OBJECTIVES

To evaluate beneficial effects of postmenopausal hormone replacement therapy (HRT) on endothelial function, measured as intraplatelet cyclic guanosine monophosphate (cGMP, mediator of nitric oxide), cyclic adenosine monophosphate (cAMP, mediator of prostacyclin) and plasma endothelin-1 (ET-1), and on monocyte activation, measured as plasma neopterin.

DESIGN

Part 1: double-blind randomized trial for 3 months; part 2: open study for 9 months.

SETTING

The study was performed at the Department of Endocrinology, University Hospital, Malmö, Sweden.

SUBJECTS

Fifty-one postmenopausal women participated in part 1 and 46 in part 2. Inclusion criteria included a history of amenorrhoea for at least 6 months before the study and body mass index >/= 24 kg m-2.

INTERVENTION

Randomization for either placebo (n = 24) or HRT (n = 27). HRT was given as 2 mg oestradiol valerate for the first 3 months with the addition of 10 mg medroxyprogesterone for 10 days every third month thereafter.

MEASUREMENTS

Performed at baseline and after 3 and 12 months of the study.

RESULTS

In the HRT group, intraplatelet cGMP increased from 0.56 (0.35-0.94) to 0.61 (0.42-3. 40) and 0.65 (0.43-1.08) pmol (109 platelets)-1 after 3 and 12 months, respectively (P = 0.01), whereas plasma ET-1 decreased from 3.2 (1.1-6.8) to 2.0 (0.8-5.1) and 1.8 (0.4-15.4) pg mL-1 (P < 0. 001). Intraplatelet cAMP and plasma neopterin were unchanged. When smokers (n = 15) and non-smokers (n = 12) in the HRT group were analysed separately, significant effects were seen only amongst smokers. The control group showed unchanged levels of cGMP, cAMP, ET-1 and neopterin.

CONCLUSIONS

These data suggest beneficial effects of HRT on endothelial function which may account for anti-atherogenic effects of HRT in postmenopausal women, especially in smokers. No effects of HRT were seen upon monocyte activation.

Oestrogens and wound healing

During the past few decades several studies have documented the deleterious impact of the menopause on bone mass and cardiovascular disease, and the reduction of risk in this area by HRT. However, the possible effects of the postmenopausal deficiency in ovarian hormones on skin and its repair post-injury, are less well documented. This review provides a survey of the literature that is available regarding the involvement and influence of oestrogens on the various phases of cutaneous repair - inflammation, proliferation and remodelling. Research carried out on the effects of oestrogens, both in terms of deficiency and replacement, on the process of wound healing in various animal models is described and discussed, together with the very limited work undertaken in humans. This area of research is of paramount clinical importance both in terms of financial cost and human suffering, since many chronic wounds such as venous ulcers, pressure sores and burns afflict the elderly population, of whom postmenopausal women comprise the majority. Clinically our aim should be to restore the integrity and function of wounded tissue as rapidly as possible after injury and it is generally believed that a better understanding of the effects of oestrogens on wound healing could lead to improved care of cutaneous wounds, and the treatment of not only the wound but of the postmenopausal woman as a whole.

Associations of C-reactive protein with measures of obesity, insulin resistance, and subclinical atherosclerosis in healthy, middle-aged women

Obesity, the insulin resistance syndrome, and atherosclerosis are closely linked and may all be determinants of an increased acute-phase response. In this study, we examined the relationship of C-reactive protein (CRP) with measures of obesity, variables of the insulin resistance syndrome, and intima-media thickness of the common carotid arteries in 186 healthy, middle-aged women selected from the general population. Associations were assessed by regression analysis. CRP was strongly associated with body mass index (BMI) and waist circumference. CRP was also associated with other variables of the insulin resistance syndrome, including blood pressure, insulin, high density lipoprotein cholesterol, triglycerides, apolipoprotein A1 (inversely), plasminogen activator inhibitor-1 antigen, and tissue-type plasminogen activator antigen. Associations between CRP and the variables of the insulin resistance syndrome disappeared after controlling for BMI but remained significant for plasminogen activator inhibitor-1 antigen only. The association of CRP with common carotid artery intima-media thickness was weak and limited to ever-smokers. BMI explained 29.7% of the variance of CRP, whereas common carotid artery intima-media thickness explained only 3.7%. The results of this population-based study indicate that adiposity is strongly associated with CRP in healthy, middle-aged women. In this population, BMI accounted for the relationship between CRP and other variables of the insulin resistance syndrome. Further studies should determine whether losing weight ameliorates the inflammatory state.

Color Doppler and hormone replacement therapy: the role of thromboxane and plasma viscosity

The aim of the study was to evaluate the plasma thromboxane and plasma viscosity in relation with Doppler flow parameters in postmenopausal patients treated with hormone replacement therapy. Thirty-two postmenopausal (follicle-stimulating hormone > 40 IU/l and estradiol < 100 pmol/l) women (mean age +/- SD, 54.7 +/- 2.9 years) participated in the study and were submitted to continuous estradiol transdermal supplementation and 12-day courses of medroxyprogesterone acetate every second month. Doppler resistances at the level of the uterine and internal carotid arteries, thromboxane plasma levels and plasma viscosity were analyzed in basal condition and after 1, 3 and 6 months. During hormone supplementation, the pulsatility index significantly decreased at the level of the analyzed arteries. Similarly, plasma thromboxane levels and plasma viscosity were significantly reduced. Significant correlations were found between thromboxane plasma concentrations, plasma viscosity and uterine artery resistances. Thus hormone replacement therapy seems to be responsible for both direct and indirect modifications at the level of the vessel wall physiology.

The biology of estrogen-mediated repair of cardiovascular injury

Women appear to be protected from cardiovascular disease until the onset of menopause. Considerable evidence supports the atheroprotective effects of endogenous and supplemental estrogens. The beneficial effects of estrogens on lipid metabolism cannot wholly explain this phenomenon. Accumulating data suggest that estrogen may act at the cellular and molecular level to influence atherogenesis. The purpose of this review is to examine lipid-independent mechanisms of estrogen-mediated atheroprotection after cardiovascular injury.

The metabolic consequences of treating postmenopausal women with non-oral hormone replacement therapy

OBJECTIVE

To define the metabolic profile of postmenopausal hormone replacement therapies when delivered through gels, patches, implants or other non-oral routes. Such information may be useful in the absence of reliable clinical data on the effects of these therapies on the risk of cardiovascular disease.

DESIGN AND METHODS

Selective literature review.

PATIENTS

Postmenopausal women.

RESULTS

Non-oral oestrogen therapies fail to invoke the hepatic response associated with oral therapy. Changes in hepatic protein synthesis are minimal and so plasma levels of binding globulins and other proteins tend to be normal. Many of the perturbations of the haemostatic system seen with oral therapy are avoided. In the absence of hepatic over-synthesis of apolipoproteins, plasma lipoprotein levels are unchanged or reduced. The direct effects of oestrogen on vascular function are apparent when the hormone is administered non-orally.

CONCLUSIONS

The net effect of non-oral estrogen therapies on the risk of cardiovascular disease is difficult to predict on the basis of current data. Some changes in plasma lipoprotein levels, such as the reduced fasting levels of triglycerides, would be considered desirable, but the cardioprotective increase in levels of high-density lipoproteins is absent. The differential effect on haemostasis markers is promising, but preliminary data relating to transdermal patches fail to support the idea that non-oral therapies will avoid the increased risk of venous thromboembolism associated with oral therapy. The ability of non-oral therapies to improve vascular function implies that they will offer postmenopausal women at least some of the cardiovascular protection seen with oral therapy.

The mythology of hormone replacement therapy

OBJECTIVE

To evaluate the literature on contraindications contained in pharmaceutical data sheets of five currently available oestrogen replacement preparations (HRT). These contraindications include cardiovascular disease, diabetes, liver diseases, otosclerosis, endometriosis, melanoma and hormone-dependent tumours.

DESIGN

Systematic review.

INTERVENTIONS

Oestrogen replacement regimens.

RESULTS

The contraindications to the five HRT preparations have been taken uncritically from the data sheets of oral contraceptives. In some of these conditions not only is HRT not contraindicated, it is indicated. The data sheets for the HRT preparations all state that cardiovascular disease is a contraindication, but systematic review shows that ischaemic heart disease, hypertension and hyperlipidaemia are not contraindications, and in ischaemic heart disease HRT may actually be indicated. Similarly, systematic review shows that diabetes, chronic liver disease, endometriosis, some cases of treated cancer of the endometrium and breast, melanoma and otosclerosis are not contraindications to HRT.

CONCLUSIONS

The information in the pharmaceutical data sheets of HRT regimens should be modified as more accurate information could influence how these preparations are prescribed by doctors as well as affect patient compliance.

Hormone replacement therapy modifies the capacity of plasma and serum to regulate prostacyclin and endothelin-1 production in human vascular endothelial cells

OBJECTIVE

To determine if hormone replacement therapy (HRT) modifies the ability of plasma or serum to regulate the synthesis of vasodilatory prostacyclin and that of vasoconstrictive endothelin-1 by cultured human umbilical vein endothelial cells.

DESIGN

Plasma and serum collected before and during the sixth treatment cycle of HRT from 13 healthy postmenopausal women were added to cultured endothelial cells.

SETTING

Helsinki University Central Hospital, Department of Obstetrics and Gynecology, Helsinki, Finland.

PATIENTS

Thirteen postmenopausal women (> or = 1 year since their last menstruation, FSH level > 40 mIU/mL [conversion factor to SI unit, 1.00], clear vasomotor symptoms) that suffered from incapacitating menopausal symptoms necessitating the initiation of HRT were studied.

INTERVENTIONS

A combined regimen consisting of 2 mg oral E2 for 12 days followed by 2.0 mg oral E2 + 1.0 mg norethisterone acetate for 10 days and 1.0 mg E2 for 6 days.

MAIN OUTCOME MEASURES

The releases of prostacyclin, as assessed by its metabolite 6-keto-prostaglandin F1 alpha, and that of endothelin-1 by cultured human umbilical vein endothelial cells in the presence of 10% plasma or 10% serum collected from the study subjects.

RESULTS

Hormone replacement therapy enhanced the ability of plasma to stimulate prostacyclin production by 21% +/- 6% (mean +/- SEM) during the E2 + norethisterone acetate phase and tended to do so also during the E2-only phase (11% +/- 10%) but caused no change in endothelin-1 release. In contrast, HRT decreased the ability of serum to stimulate prostacyclin production by 12% +/- 5% during the E2-only phase and increased that of endothelin-1 by 8% +/- 4% during the E2 + norethisterone acetate phase.

CONCLUSION

Because plasma flushes endothelial cells in vivo, our data on the HRT-induced stimulation of the capacity of plasma to enhance the production of vasoprotective prostacyclin without a concomitant change in endothelin-1 release in cultured human umbilical vein endothelial cells may provide one new explanation for the cardiovascular protection of HRT.

Effect of marine oils supplementation on coagulation and cellular activation in whole blood

A study was performed to explore the effects of supplemental intake of various marine oils known to be part of the Eskimo diet. Healthy men and women (134) were randomly selected to consume 15 mL/d of oil from blubber of seal, cod liver, seal/cod liver, blubber of Minke whale, or no oil for ten weeks. Total cholesterol was unchanged in the oil groups, whereas high density lipoprotein cholesterol increased 7% in the seal/cod liver oil (CLO) group (P < 0.05) and 11% in the whale oil group (P < 0.005). Triacylglycerol was significantly reduced in the CLO group only. The concentration of prothrombin fragment 1 + 2 was reduced 25% (P < 0.05) after whale oil supplementation. No change in fibrinogen or factor VIIc was detected. Tumor necrosis factor generation in lipopolysaccharide (LPS)-stimulated blood was 30% reduced after whale oil (P < 0.05), but was unaffected by intake of seal or CLO. The LPS-induced tissue factor activity in monocytes was reduced to a significant degree only in the seal/CLO group (34%) and whale oil group (35%) (P < 0.05). The most dramatic change in thromboxane B2 in LPS-stimulated blood was seen after whale oil intake with 44% reduction (P < 0.01). Supplementation of a regular diet with a combination of seal oil and CLO and especially with whale oil seems to have beneficial effects on several products thought to be associated with cardiovascular and thrombotic diseases.