Interaction of hemostatic genetics with hormone therapy: new insights to explain arterial thrombosis in postmenopausal women

Gender differences in coronary angiography, subsequent interventions, and outcomes among patients with acute coronary syndromes

BACKGROUND

The objective was to investigate whether gender disparities are found in referrals of patients with acute coronary syndromes to percutaneous coronary interventions (PCIs) or coronary artery bypass grafting (CABG) and, furthermore, to study gender differences in complications and mortality.

METHODS

All consecutive coronary angiographies (CAs) and PCIs performed in Sweden and Iceland are prospectively registered in the Swedish Coronary Angiography and Angioplasty Registry. For the present analysis, data of patients with acute coronary syndromes, enrolled in 2007-2011, were used to analyze gender differences in revascularization, in-hospital complications, and 30-day mortality.

RESULTS

A total of 106,881 CAs were performed during the study period. In patients with significant coronary artery disease, the adjusted odds ratio (OR) for women to undergo PCI compared with men was 0.95 (95% CI 0.92-0.99) and 0.81 (0.76-0.87) for referrals to CABG. In patients with 1-vessel disease, women were less likely to undergo PCI than men, but women with 2- or 3-vessel or left main stem disease were more likely to undergo PCI. All in-hospital complications after CA followed by PCI were more frequent among women (adjusted OR 1.58 [1.47-1.70]). There was no gender difference in adjusted 30-day mortality after PCI (1.02 [0.92-1.12]) and after CABG (0.97 [0.72-1.31]).

CONCLUSIONS

After CA showing 1-vessel disease, women as compared with men were less likely to undergo PCI. In the group with 2- or 3-vessel disease or left main stem stenosis, women were more likely to undergo PCI but less likely to undergo CABG. However, there was no gender difference in 30-day mortality.

Human cells involved in atherosclerosis have a sex

The influence of sex has been largely described in cardiovascular diseases. Atherosclerosis is a complex process that involves many cell types such as vessel cells, immune cells and endothelial progenitor cells; however, many, if not all, studies do not report the sex of the cells. This review focuses on sex differences in human cells involved in the atherosclerotic process, emphasizing the role of sex hormones. Furthermore, we report sex differences and issues related to the processes that determine the fate of the cells such as apoptotic and autophagic mechanisms. The analysis of the data reveals that there are still many gaps in our knowledge regarding sex influences in atherosclerosis, largely for the cell types that have not been well studied, stressing the urgent need for a clear definition of experimental conditions and the inclusion of both sexes in preclinical studies.

Synergistic Effect of a Physiological Ratio of Estradiol and Testosterone in the Treatment of Early-stage Atherosclerosis

BACKGROUND AND AIMS

Clinical trials and epidemiological data suggest that estrogen replacement therapy (ERT) fails to reduce cardiovascular events in postmenopausal women with coronary heart disease (CHD). The high concentration of estrogen supplementation may increase the risk of thrombosis and result in testosterone deficiency, which is considered the main reason for failure. Thus, we hypothesized that a physiologic dosage of estradiol combined with testosterone may become a new therapeutic strategy in postmenopausal women with CHD.

METHODS AND RESULTS

We used human umbilical vein endothelial cells (HUVECs) and female C57BL/6 mice as the experimental subjects. With the HUVECs, we found an appropriate E2/T ratio of 5:1 (5×10(-8) mol/L estradiol and 10(-8) mol/L testosterone), which has a significant anti-apoptotic effect on HUVECs by inducing a C-reactive protein. In the in vivo study, we verified the beneficial effects of the defined appropriate E2/T ratio in mice with early stage atherosclerosis. We found that replacement therapy with the defined appropriate E2/T ratio had beneficial effects of reducing the lipid lesions, reducing the formation of foam cells, reducing endothelial injury, modulating the coagulation system function and inhibiting inflammation and was significantly more effective than either estradiol or testosterone supplementation alone.

CONCLUSION

The present study demonstrated that estradiol and testosterone have a synergistic effect on early stage atherosclerosis, and replacement therapy with the defined appropriate E2/T ratio can significantly suppress the development of atherosclerosis through reducing the lipid lesions, reducing the formation of foam cells, reducing endothelial injury, modulating the coagulation system function and inhibiting inflammation.

Likelihood and predictors of ST-elevation in patients hospitalized for myocardial infarction

Importance

Emergency treatment options in myocardial infarction are guided by presence or absence of ST-elevations in electrocardiography. Occurrence and factors associated with ST-presentation in different population groups are however inadequately known.

Objective

To determine likelihood and patient features associated with ST-elevations in myocardial infarction.

Design

Nationwide registry study including 22 hospitals with angiolaboratory during an eight year period in Finland.

Setting

Hospitalized care.

Participants

68,162 consecutive patients aged ≥30 with myocardial infarction.

Measures

Likelihood and patient features associated with presence of ST-elevations.

Results

Myocardial infarction presented with ST-elevation in 37.5% (CI 37.0–37.9%) and without in 62.5% (CI 61.9–63.1%) of patients, p<0.0001. Majority of patients aged 30–59 years with myocardial infarction had ST-elevation, but among octogenarians ST-elevations were present in only 24.7%. Presence of ST-elevations decreased with age by estimated 15.6% (CI 15.0–16.2%) per 10 year increase (p<0.0001). Men aged 40–79 years had significantly higher rate for ST-elevation myocardial infarction compared to women. Sex-based difference in presentation of myocardial infarction declined with increasing age. Overall, men had a 13% (CI 11–15%, p<0.0001) higher relative risk for ST-elevations compared to women when adjusted for age and co-morbidities. Diabetes, atrial fibrillation, peripheral or cerebral artery disease, chronic pulmonary disease, malignancy, and renal insufficiency were associated with absence of ST-elevations in myocardial infarction in multivariate analysis.

Conclusions and Relevance

Myocardial infarction presents with ST-elevations more commonly in men. Presence of ST-elevations decreases with increasing age. Diabetes, atrial fibrillation, peripheral or cerebral artery disease, chronic pulmonary disease, malignancy, and renal insufficiency are associated with absence of ST-elevations in myocardial infarction. These findings may help to predict likelihood of ST-elevations in a patient with myocardial infarction.

Pharmacogenomics, pharmacokinetics and pharmacodynamics: interaction with biological differences between men and women

Pharmacological response depends on multiple factors and one of them is sex-gender. Data on the specific effects of sex-gender on pharmacokinetics, as well as the safety and efficacy of numerous medications, are beginning to emerge. Nevertheless, the recruitment of women for clinical research is inadequate, especially during the first phases. In general, pharmacokinetic differences between males and females are more numerous and consistent than disparities in pharmacodynamics. However, sex-gender pharmacodynamic differences are now increasingly being identified at the molecular level. It is now even becoming apparent that sex-gender influences pharmacogenomics and pharmacogenetics. Sex-related differences have been reported for several parameters, and it is consistently shown that women have a worse safety profile, with drug adverse reactions being more frequent and severe in women than in men. Overall, the pharmacological status of women is less well studied than that of men and deserves much more attention. The design of clinical and preclinical studies should have a sex-gender-based approach with the aim of tailoring therapies to an individual's needs and concerns.

Emerging evidence of the importance of rapid, non-nuclear estrogen receptor signaling in the cardiovascular system

Estrogen receptors are classically known as ligand-activated transcription factors that regulate gene transcription in cells in response to hormone binding. In addition to this "genomic" signaling pathway, a "rapid, non-nuclear" signaling pathway mediated by cell membrane-associated estrogen receptors also has been recognized. Although for many years there was little evidence to support any physiological relevance of rapid-signaling, very recently evidence has been accumulating supporting the importance of the rapid, non-nuclear signaling as potentially critical for the protective effects of estrogen in the cardiovascular system. Better understanding of the rapid, non-nuclear signaling potentially provides an opportunity to design "pathway-specific" selective estrogen receptor modulators capable of differentially regulating non-nuclear vs. genomic effects that may prove useful ultimately as specific therapies for cardiovascular diseases.

Genetic polymorphisms associated with carotid artery intima-media thickness and coronary artery calcification in women of the Kronos Early Estrogen Prevention Study

Menopausal hormone treatment (MHT) may limit progression of cardiovascular disease (CVD) but poses a thrombosis risk. To test targeted candidate gene variation for association with subclinical CVD defined by carotid artery intima-media thickness (CIMT) and coronary artery calcification (CAC), 610 women participating in the Kronos Early Estrogen Prevention Study (KEEPS), a clinical trial of MHT to prevent progression of CVD, were genotyped for 13,229 single nucleotide polymorphisms (SNPs) within 764 genes from anticoagulant, procoagulant, fibrinolytic, or innate immunity pathways. According to linear regression, proportion of European ancestry correlated negatively, but age at enrollment and pulse pressure correlated positively with CIMT. Adjusting for these variables, two SNPs, one on chromosome 2 for MAP4K4 gene (rs2236935, β = 0.037, P value = 2.36 × 10(-06)) and one on chromosome 5 for IL5 gene (rs739318, β = 0.051, P value = 5.02 × 10(-05)), associated positively with CIMT; two SNPs on chromosome 17 for CCL5 (rs4796119, β = -0.043, P value = 3.59 × 10(-05); rs2291299, β = -0.032, P value = 5.59 × 10(-05)) correlated negatively with CIMT; only rs2236935 remained significant after correcting for multiple testing. Using logistic regression, when we adjusted for waist circumference, two SNPs (rs11465886, IRAK2, chromosome 3, OR = 3.91, P value = 1.10 × 10(-04); and rs17751769, SERPINA1, chromosome 14, OR = 1.96, P value = 2.42 × 10(-04)) associated positively with a CAC score of >0 Agatston unit; one SNP (rs630014, ABO, OR = 0.51, P value = 2.51 × 10(-04)) associated negatively; none remained significant after correcting for multiple testing. Whether these SNPs associate with CIMT and CAC in women randomized to MHT remains to be determined.

Platelet biology and response to antiplatelet therapy in women: implications for the development and use of antiplatelet pharmacotherapies for cardiovascular disease

Women are underrepresented in cardiovascular studies, even as their preponderance in the aging population steadily increases. Although concerns have been raised about the differential benefit of antiplatelet medications for women, the propensity for increased bleeding among women has also been recognized. A better understanding of the factors contributing to the observed sex-related differences in platelet biology is warranted. These factors include differences in the frequency and expression of genetic polymorphisms affecting platelet responsiveness to agonists (with and without antiplatelet therapies), which might be obtained through population-based studies and in large controlled clinical trials; inflammatory marker levels and their influence on atherothrombotic risk, and the role of specific hormones in mediating platelet activation and function. Knowledge gained about these mechanistic factors might inform the development of sex-specific antithrombotic treatment regimens that confer optimized safety and efficacy.

Venous thrombosis in the elderly: incidence, risk factors and risk groups

The incidence of venous thrombosis (VT) increases sharply with age: it is very rare in young individuals (<1 per 10,000 per year) but increases to ∼ 1% per year in the elderly, which indicates that aging is one of the strongest and most prevalent risk factor for venous thrombosis. The cause of this steep age gradient is as yet, unexplained. The aim of this review was to provide an overview of studies on the effect of conventional risk factors as well as age-specific risk factors for thrombosis in the elderly. Limited data are available on risk factors for thrombosis in the elderly, i.e. all results are based on small study groups. Results indicate that, of the conventional risk factors, malignant disease, the presence of co-morbidities and the genetic risk factors factor (F)V Leiden and the prothrombin mutation seem to be associated with an increased risk of venous thrombosis. In the elderly, the population attributable risk (PAR) of malignancy is approximately 35%, for co-morbidities a PAR up to 25% is found, and the contribution of genetic risk factors to the thrombosis incidence is estimated to be 7-22%. Age-specific risk factors of thrombosis, i.e. endothelial dysfunction and frailty may be important in the explanation of the increased incidence of VT in the elderly. In conclusion, as aging is a major risk factor for thrombosis, further identification of the risk factors for thrombosis in the elderly is needed to elucidate the age gradient of the incidence of VT and to target preventive measures.

The differential effect of estrogen, estrogen–progestin and tibolone on coagulation inhibitors in postmenopausal women

OBJECTIVES

Hormone therapy increases the risk of venous thromboembolism, possibly through a negative effect on coagulation inhibitors. The aim of the study was to assess the effect of conjugated equine estrogens alone or in combination with medroxyprogesterone acetate, low-dose 17beta-estradiol combined with norethisterone acetate and tibolone on inhibitors of coagulation.

METHODS

Two hundred and sixteen postmenopausal women received orally either conjugated equine estrogens 0.625 mg (CEE, n=24) or tibolone 2.5 mg (n=24) or CEE+medroxyprogesterone acetate 5 mg (CEE/MPA, n=34) or 17beta-estradiol 1 mg+norethisterone acetate 0.5 mg (E2/NETA, n=66) or no therapy (control, n=68) for 12 months. Plasma antithrombin, protein C and total protein S were measured at baseline and at 12 months.

RESULTS

CEE, CEE/MPA and E2/NETA treatment were associated with a significant decrease in antithrombin levels (CEE: baseline 235.6+/-47.6 mg/l, follow-up 221.3+/-48.3 mg/l, p=0.0001; CEE/MPA: baseline 251.1+/-38.6 mg/l, follow-up 225.0+/-42.6 mg/l, p=0.009; E2/NETA: baseline 257.1+/-59.4 mg/l, follow-up 227.1+/-50.4 mg/l, p=0.007; tibolone: baseline 252.6+/-62.4 mg/l, follow-up 261.9+/-59.1 mg/l, p=0.39). Protein C decreased significantly in the CEE and CEE/MPA groups (CEE: baseline 3.64+/-1.17 mg/l, follow-up 2.48+/-1.47 mg/l, p=0.004; CEE/MPA: baseline 3.24+/-1.23 mg/l, follow-up 2.61+/-1.38 mg/l, p=0.001; E2/NETA: baseline 3.24+/-1.10 mg/l, follow-up, 3.15+/-1.11 mg/l, p=0.08; tibolone: baseline 3.26+/-1.25 mg/l, follow-up 3.09+/-1.32 mg/l, p=0.37). Protein S decreased significantly only in the CEE/MPA group (CEE: baseline 19.4+/-2.76 mg/l, follow-up 18.0+/-2.45 mg/l, p=0.56; CEE/MPA: baseline 18.4+/-3.42 mg/l, follow-up 14.5+/-3.43 mg/l, p=0.005; E2/NETA: baseline 19.0+/-3.11 mg/l, follow-up 19.5+/-3.43 mg/l, p=0.18; tibolone: baseline 18.5+/-3.09 mg/l, follow-up 18.0+/-4.09 mg/l, p=0.32).

CONCLUSIONS

Estrogen and estrogen-progestin therapy are associated with a reduction in coagulation inhibitors, the extent of which depends on the regimen administered. Tibolone appears to have no effect on inhibitors of coagulation.

Spontaneous Hepatic Hemorrhage in Older Women

Spontaneous liver hemorrhage in older women is not well described. We report an experience with five postmenopausal women who spontaneously bled from the liver. All five patients presented with acute bleeding. Four were treated nonoperatively. No tumor was identified in any patient. Four patients acutely were discharged alive and well, but one died after operation to control bleeding. Spontaneous liver hemorrhage can occur in a variety of clinical settings, but an association with older women taking hormone replacement and anticoagulation has not been reported.

Ageing, oestrogen, platelets and thrombotic risk

1. Adverse thrombotic cardiovascular events increase in women coincident with the onset of menopause. 2. Age past menopause may be an important variable in defining the benefit/risk of hormone treatments. 3. Few studies have examined hormonal status as a variable of ageing using a polygenomic approach of both humoral and cellular components of the coagulation system. 4. Longitudinal studies of a global set of platelet functions that define procoagulant activity (i.e. adhesion, aggregation, secretion and thrombin production) in individuals with documented hormonal status are needed to better understand how hormonal changes associated with ageing impact thrombotic risk.

Estrogen receptor alpha (ESR1) PvuII and XbaI gene polymorphisms in ischemic stroke in a Hungarian population

BACKGROUND

Ischemic stroke is a multifactorial disorder with genetic and environmental components. The aim of our study was to investigate whether two polymorphisms of the estrogen receptor alpha (ESR1) gene (ESR1 c.454-397T>C and c.454-351A>G) are associated with ischemic stroke in a Caucasian population from Hungary.

METHODS

One hundred and ninety-eight patients with ischemic stroke and 180 control subjects were enrolled in this case-control study. Ischemic stroke subtypes were categorized according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification as large-artery atherosclerosis, small-artery occlusion, cardioembolism or stroke of other determined etiology. The ESR1 PvuII and XbaI genotypes were determined using the PCR-RFLP method.

RESULTS

There were no significant differences in the genotype, allele and haplotype frequencies of PvuII and XbaI polymorphisms between the group of patients with ischemic stroke and the control group. Furthermore, ESR1 PvuII and XbaI genotypes, alleles and haplotypes were not associated with any subtype of ischemic stroke.

CONCLUSIONS

We did not observe an association between ESR1 PvuII and XbaI gene polymorphisms and ischemic stroke or any subtype of ischemic stroke. However, further studies are needed to explore the complex interaction between environmental factors and ESR1 gene polymorphisms in the risk of ischemic stroke, particularly in ethnically different populations.

Myocardial infarction with normal coronary arteries: a conundrum with multiple aetiologies and variable prognosis: an update

The existence of myocardial infarction despite angiographically normal coronary arteries was recognized more than 30 years ago. Since then, various series of such patients have been described, but the aetiology and pathogenesis of the condition are still a source of debate. Evidence exists for a role of coronary vasospasm, thrombosis, embolization and inflammation, per se or combined, in determining the occurrence of myocardial infarction in the presence of angiographically normal coronary arteries. Endothelial dysfunction, possibly superimposed to nonangiographically evident atherosclerosis, may be an underlying common feature predisposing to the acute event. Additionally, myocarditis may explain some of these occurrences. Myocardial infarction with normal coronary arteries is therefore likely the result of multiple pathogenetic mechanisms. Although most reports emphasize the good prognosis of this condition, in general much better than myocardial infarction with coronary artery disease, prognosis is likely variable according to the underlying mechanism. This review summarizes current knowledge on this condition and examines areas of recent progress.

Complex actions of sex steroids in adipose tissue, the cardiovascular system, and brain: Insights from basic science and clinical studies

Recent publications describing the results of the Women's Health Initiative (WHI) and other studies reporting the impact of hormone therapy on aging women have spurred reexamination of the broad use of estrogens and progestins during the postmenopausal years. Here, we review the complex pharmacology of these hormones, the diverse and sometimes opposite effects that result from the use of different estrogenic and progestinic compounds, given via different delivery routes in different concentrations and treatment sequence, and to women of different ages and health status. We examine our new and growing appreciation of the role of estrogens in the immune system and the inflammatory response, and we pose the concept that estrogen's interface with this system may be at the core of some of the effects on multiple physiological systems, such as the adipose/metabolic system, the cardiovascular system, and the central nervous system. We compare and contrast clinical and basic science studies as we focus on the actions of estrogens in these systems because the untoward effects of hormone therapy reported in the WHI were not expected. The broad interpretation and publicity of the results of the WHI have resulted in a general condemnation of all hormone replacement in postmenopausal women. In fact, careful review of the extensive literature suggests that data resulting from the WHI and other recent studies should be interpreted within the narrow context of the study design. We argue that these results should encourage us to perform new studies that take advantage of a dialogue between basic scientists and clinician scientists to ensure appropriate design, incorporation of current knowledge, and proper interpretation of results. Only then will we have a better understanding of what hormonal compounds should be used in which populations of women and at what stages of menopausal/postmenopausal life.

Therapeutic implications of the gender-specific aspects of cardiovascular disease

The manifestations of cardiovascular diseases differ between men and women, as do outcomes after therapeutic interventions. It is important that those involved in drug discovery and development, as well as disease treatment, are aware of these differences because such variations are likely to have an increasing role in therapeutic decisions in the future. Here, I review gender differences in the most frequent cardiovascular diseases and their underlying sex-dependent molecular pathophysiology, and discuss gender-specific effects of current cardiovascular drugs and the implications for novel strategies for drug development.

Polymorphisms associated with thrombophilia and vascular homeostasis and the timing of menarche and menopause in 728 white women

OBJECTIVE

Genetic factors have been proposed as modulators of the timing of natural menopause. Single nucleotide polymorphisms (SNPs) of genes associated with thrombophilia and vascular homeostasis may interfere with ovarian function and thus are candidate genes for early menopause. We attempted to assess the association of SNPs and the timing of menarche and natural and surgical menopause in an ethnically homogenous cohort of Middle European white women.

DESIGN

In the present cross-sectional study, eight SNPs of six genes involved in vascular function and homeostasis were analyzed by sequencing-on-chip using solid-phase polymerase chain reaction on oligonucleotide microarrays in 728 white women: factor V (F5) Leiden G1691A, factor II (F2) prothrombin G20210A, plasminogen activator inhibitor1 (PAI-1) 4G/5G, angiotensinogen (AGT) Met235Thr, endothelial nitric oxide synthase (NOS3) T768C and NOS3 Glu298Asp, apolipoprotein E-1 (APOE-1) Cys112Arg, and APOE-2 Arg158Cys. The women's reproductive and medical histories were correlated to genotypes.

RESULTS

In a univariate analysis, current smoking (P = 0.01) and the presence of at least one mutant allele of F5 Leiden (P = 0.03) and APOE-2 (P = 0.03) were significantly associated with a reduced age at natural menopause. The presence of at least one mutant allele of F5 Leiden (P = 0.02) and a body mass index above 25 kg/m (P = 0.009) were significantly associated with an increased risk for surgical menopause by premenopausal hysterectomy (odds ratio = 2.6, 95% CI, 1.2-5.6; odds ratio = 1.9, 95% CI, 1.2-3.0, respectively). Age at menarche was not affected by the carriage of any of the investigated SNPs. Applying stepwise linear regression models considering all two-way interactions, no interactions were found among different SNPs or between SNPs and environmental and lifestyle parameters.

CONCLUSION

We identified various genetic and personal history parameters influencing age at natural menopause and the risk of undergoing premenopausal hysterectomy. To the best of our knowledge, we present the largest study to date determining SNPs as contributors to the genetic control of the timing of natural and surgical menopause.

Molecular and cellular basis of cardiovascular gender differences

Cardiovascular diseases (CVDs), the major cause of morbidity and mortality for both men and women, occur uncommonly in premenopausal women, but their incidence rises sharply after the menopausal transition. Cardiovascular gender differences are apparent long before CVDs appear in men and women, and improved understanding of the biology underlying these differences has the potential to advance the diagnosis and treatment of CVDs in both sexes. This review considers gender differences in the molecular and cellular physiology of the heart and blood vessels in health and disease, highlighting understudied areas that can help resolve the current controversy regarding hormone replacement therapy and improve cardiovascular health in women.

Genetic thrombophilia has pleiotropic effects in pregnancy

Genetic thrombophilia has been established as a risk factor for pregnancy-associated disorders, such as thrombosis, early and late miscarriage, and pre-eclampsia. Associations between the factor V (F5) Leiden G1691A and the prothrombin/factor II (F2) G20210A SNPs and pre-eclampsia have been evaluated in over 50 association studies. A pooled analysis of 23 and 11 studies demonstrates that carriage of the F5 Leiden G1691A (p < 0.001; odds ratio [OR] 2.0; 95% confidence interval [CI] 1.6-2.5) and the F2 G20210A (p < 0.001; OR 1.8; 95% CI 1.1-2.9) SNPs is significantly associated with pre-eclampsia. Besides pre-eclampsia, genotyping for the F5 Leiden G1691A and the F2 G20210A SNPs is also useful for individual risk assessment regarding pregnancy-associated thrombosis. Carriers of the F5 Leiden G1691A SNP will develop this condition in 6.4% of heterozygotes and in 8.9-16.7% of homozygotes. A total of 6.2% of women with the F2 G20210A SNP and 17.8% of women with simultaneous carriage of the F5 Leiden G1691A and F2 G20210A SNPs will develop pregnancy-associated thrombosis. Both the F5 Leiden G1691A and F2 G20210A SNPs are also risk factors of early recurrent, late recurrent and late spontaneous miscarriage based on a published meta-analysis of 31 studies. These women may benefit from prophylactic heparinization. Six case-control and cohort studies of 687 women with genetic thrombophilia document live birth rates of 82% (181/221) using low-molecular-weight heparin or fractionated heparin compared with 20% (95/466) without therapy (p < 0.001, OR 17.7; 95% CI 12.2-25.5). Based on the data in the literature, including association studies and meta-analyses of these association studies, it can be concluded that genetic thrombophilia due to carriage of the F5 Leiden G1691A and F2 G20210A SNPs is a significant and clinically relevant risk factor for pre-eclampsia, pregnancy-associated thrombosis, and early and late miscarriages.

DNA microarray–based analysis of single nucleotide polymorphisms may be useful for assessing the risks and benefits of hormone therapy

OBJECTIVE

To determine what percentage of women can be given individualized counseling based on genetic information, as single nucleotide polymorphisms (SNPs) are associated with risks and benefits of estrogen therapy and hormone therapy such as thrombosis, myocardial infarction, breast cancer, and bone protection.

DESIGN

Cross-sectional study.

SETTING

Academic research institution.

PATIENT(S)

A consecutive series of 2,507 perimenopausal and postmenopausal women.

INTERVENTION(S)

Peripheral venous puncture and multiplex polymerase chain reaction on a microarray system.

MAIN OUTCOME MEASURE(S)

Analysis of 22 SNPs of 17 genes: AGTMet235Thr, APOECys112Arg, APOEArg158Cys, COMTVal158Met, CYP17-34T>C, CYP191558C>T, CYP19Arg264Cys, CYP1A16235T>C, CYP1A1Ile462Val, CYP1B1Leu432Val, CYP1B1Asn453Ser, HSD17B1-27A>C, ER-alphaIVS-401T>C, prothrombin20210G>A, factor V Leiden, eNOS-786T>C, eNOSGlu298Asp, MRSer810Leu, MTHFR677C>T, PAI 15G>4G, SRD5A2Val89Leu, and VDRb>B.

RESULT(S)

Among the women in the study, 66% had at least two homozygous mutant SNPs of interest. A thrombophilic disposition was found in 9.9% of women, and 23% of women had at least two SNPs associated with an increased risk of breast cancer (COMT, CYP17, CYP19, CYP1A1, and CYP1B1). The SNPs predisposing women to cardiovascular pathologies (e.g., APOE, AGT, eNOS, and PAI 1) were found in 12.3% of women. Carriage of SNPs predisposing to early postmenopausal bone loss and osteoporosis (ER-alpha and VDR) were found in 26.7% of women.

CONCLUSION(S)

These data suggest that the assessment of SNPs associated with risks and benefits of estrogen/hormone therapy may be a new means to individualize counseling about and prescription of estrogen/hormone therapy in up to 66% of women.

[Impact of HRT on the arterial carotid vascular tree]

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

Association between estrogen receptor alpha gene variation and cardiovascular disease

CONTEXT

Estrogen and related hormone therapies activate estrogen receptors, which in turn regulate genes for several cardiovascular disease (CVD) risk factors. Relatively little is known, however, about the impact of genetic variation in estrogen receptor alpha (ESR1) on CVD risk.

OBJECTIVE

To investigate whether the ESR1 c.454-397T>C polymorphism is associated with CVD risk.

DESIGN, SETTING, AND PARTICIPANTS

Prospective study of 1739 unrelated men and women from the population-based offspring cohort of the Framingham Heart Study, who were followed up from 1971 to 1998.

MAIN OUTCOME MEASURES

Total atherosclerotic CVD events, defined as recognized or unrecognized myocardial infarction (MI), angina pectoris, coronary insufficiency, intermittent claudication, coronary heart disease death, or atherothrombotic stroke (n = 178); major atherosclerotic CVD, defined as recognized acute MI, coronary insufficiency, coronary heart disease death, or atherothrombotic stroke (n = 83); and recognized acute MI (n = 59).

RESULTS

Twenty percent of participants (n = 352) were homozygous for the ESR1 c.454-397C allele. After adjustment for covariates (age, sex, body mass index, hypertension, diabetes mellitus, total cholesterol, high-density lipoprotein cholesterol, and cigarette smoking), the CC genotype was significantly associated with major atherosclerotic CVD, with an odds ratio of 2.0 (95% confidence interval [CI], 1.3-3.2; P =.004) compared with individuals with the CT or TT genotypes. Participants with the CC genotype had 3.0-fold greater odds of MI (95% CI, 1.7-5.2; P<.001) compared with those with the CT or TT genotype. The results remained significant when analyses were restricted to men; too few women had events to study them separately.

CONCLUSIONS

Individuals with the common ESR1 c.454-397CC genotype have a substantial increase in risk of MI. Whether ESR1 c.454-397T>C is causally related to MI risk or in linkage disequilibrium with 1 or more causal variants remains to be determined. These findings support the importance of estrogen receptors in CVD susceptibility, especially in men. Estrogen receptor variation also has potential to explain recent conflicting data regarding the effects of hormone therapy on CVD susceptibility in women.

Genetic variants of coagulation factor XIII, postmenopausal estrogen therapy, and risk of nonfatal myocardial infarction

We hypothesized that possession of either of 2 functional coagulation factor XIII polymorphisms, one within subunit A (Val34Leu) and one within subunit B (His95Arg), might modulate the prothrombotic effects of estrogen and help to explain the variation in incidence of arterial thrombotic events among postmenopausal women using hormone replacement therapy. In a population-based case-control study of 955 postmenopausal women, we assessed the associations of factor XIII genotypes and their interactions with estrogen therapy on risk of nonfatal myocardial infarction (MI). The presence of the factor XIIIA Leu34 allele was associated with a reduced risk of MI (odds ratio [OR] = 0.70, 95% confidence interval [95% CI] = 0.51-0.95). The presence of the factor XIIIB Arg95 allele had little association with MI risk. Neither factor XIII polymorphism alone significantly modified the association between the risk of MI and current estrogen use. In exploratory analyses, however, there was a significant factor XIII subunit gene-gene interaction. Compared to women homozygous for both common factor XIII alleles, the Arg95 variant was associated with a reduced risk of MI in the presence of the Leu34 variant (OR = 0.36, 95% CI = 0.17-0.75) but not in the absence of the Leu34 variant (OR = 1.11, 95% CI = 0.69-1.79). Moreover, among women who had at least 2 copies of the variant factor XIII alleles and were current estrogen users, the risk of MI was reduced by 70% relative to estrogen nonusers with fewer than 2 factor XIII variant alleles (P value for interaction =.03). If confirmed, these findings may permit a better assessment of the cardiovascular risks and benefits associated with postmenopausal estrogen therapy.

ER-alpha variants and the cardiovascular effects of hormone replacement therapy

There is an accumulating body of evidence linking estrogen receptor-alpha (ER-alpha) gene polymorphisms with variation in cardiovascular risk factors or disease. The ER-alpha IVS1-397 T/C (PvuII), IVS1-351 A/C (XbaI) and the promoter region TA repeat polymorphisms have received the most attention. If ER-alpha genetic variants identify women at high risk for cardiovascular events, this information could be used to improve clinical decisions regarding the use of hormone replacement therapy (HRT). More detailed haplotype and genome-wide studies of many of the major HRT clinical trial cohorts are currently underway and these efforts promise to clarify many outstanding issues concerning estrogen action and cardiovascular disease.

Role of estrogen receptor-alpha in pharmacogenetics of estrogen action

PURPOSE OF REVIEW

To summarize recent data regarding the role of estrogen receptor-alpha polymorphisms in determining the response to estrogen therapy or the risk of clinical cardiovascular events.

RECENT FINDINGS

Recent clinical trials of hormone replacement therapy for cardiovascular disease have yielded surprisingly negative results, shifting clinical opinions from a position of presumed cardiovascular benefit to one of confirmed harm. Understanding why hormone replacement therapy has beneficial effects on intermediate risk markers for cardiovascular disease, but produces an increase in cardiovascular events, is an important public health question with the potential to elucidate fundamentally important aspects on atherogenesis, cardiovascular disease, and the biology of estrogen action. One question concerning the cardiovascular effects of hormone replacement therapy is whether genetic factors can substantially modify individual responses to estrogen treatment. New clinical trial evidence is emerging that links the presence of particular variants in the estrogen receptor to the response of HDL and other intermediate endpoints to hormone replacement therapy.

SUMMARY

One or more common variants in estrogen receptor-alpha are associated with a differential response to hormone replacement therapy in several domains of estrogen action. However, the effect of these variants on the risk of clinical cardiovascular events in the setting of hormone replacement therapy is not yet known. Additional research focusing on the clinical impact of common variants in estrogen receptor-alpha, estrogen receptor-beta and the progesterone receptor promise to improve clinical decision-making concerning the use of hormone replacement therapy and other novel estrogen agonists.

Postmenopausal hormone replacement therapy and atherosclerosis

The role of postmenopausal hormone replacement therapy (HRT) in the prevention of cardiovascular disease (CVD) has evolved since estrogen was first proposed to be vasoprotective. The discovery of novel molecular signaling pathways involving the estrogen receptor in vascular cells and the elucidation of numerous biologic mechanisms have suggested that HRT may exert its potentially beneficial or adverse cardiovascular effects through multiple mechanisms. Estrogen has genomic, as well as rapid nongenomic, effects that alter vasodilation, coagulation, inflammation, and the vascular injury response, some of which may have potentially beneficial or adverse cardiovascular consequences. Current guidelines do not support the use of HRT in the secondary prevention of CVD, and recent results of primary prevention trials show evidence of increased early cardiovascular risk and no overall health benefit with combination estrogen-progestin treatment. The role of estrogen alone in the primary prevention of CVD awaits the results of ongoing trials. The key to the use of estrogen replacement therapy for the prevention of CVD may be to target therapy before atherosclerosis is evident, and to identify women with genetic susceptibility who may be at increased risk for an adverse outcome associated with therapy.

Elevated levels of Factor XI are associated with cardiovascular disease in women

Coronary artery disease (CAD) continues to be the most frequent cause of death among women in the United States. Although elevated levels of clotting factors have been associated with CAD, few of these studies have been performed in women. Elevated levels of Factor XI have previously been associated with venous thrombosis, but little is known about its effect on arterial thrombosis. We selected women referred for cardiac catheterization who were found to have either normal coronaries or evidence of severe CAD and compared levels of homocysteine, anticardiolipin IgG/IgM antibodies, fibrinogen, platelet count, Factor VII, Factor VIII and Factor XI. Women with severe CAD had significantly higher levels of Factor XI than those without CAD (128% vs. 82%, p<0.04). Statistical adjustment for age, diabetes, hypertension, total cholesterol (TC), current smoking, or BMI had no effect on the independent association between CAD status and Factor XI. Factor XI was higher in women with total cholesterol levels >6.18 mmol/l (>239 mg/dl) compared with normocholesteremic women and was also higher in the upper tertile of age, but even when adjusted for these, the association remained significant. This initial study suggests that Factor XI may be an important parameter in arterial as well as venous thrombosis.