Hormone replacement therapy and cardiovascular disease: increased risks of venous thromboembolism and stroke, and no protection from coronary heart disease

An obvious antinomy, superior sagittal sinus thrombosis in a patient with immune thrombocytopenia: Case report and a review of literatures

RATIONALE

Immune thrombocytopenia (ITP) is an autoimmune disease with an increased risk of bleeding. However, in recent years, it has been reported that patients with this hemorrhagic disease have the risk of thrombosis and embolism.

PATIENT CONCERNS AND DIAGNOSIS

The patient, in this case, was a young female who was diagnosed with ITP. When the platelet count was low, she had skin, mucosa, internal organs, and intracranial hemorrhage. In the process of ITP and hemostatic treatment, superior sagittal sinus thrombosis occurred when she was still bleeding.

INTERVENTIONS

She was given treatments for reducing intracranial pressure and controlling epilepsy.

OUTCOMES

And then the embolectomy operation failed. It was suggested in this case that ITP patients with severe thrombocytopenia and bleeding tendency also have a risk of having thrombotic disease. We reviewed literatures regarding the mechanism of the simultaneous occurrence of 2 antinomy diseases and cerebral venous thrombosis.

LESSONS

There are many factors for ITP patients to have thrombosis involving ITP itself, its treatment and the patients' constitution, medical history, and former medication. ITP is not only a hemorrhagic disease but also a thrombotic disease. Clinicians should be alert to the risk of thrombotic diseases in ITP treatment. Therefore thrombus monitoring and screening should be carried out, and early prevention or appropriate anticoagulant treatment should be selected, especially for patients with high risk.

Comparative Utility of Acupuncture and Western Medication in the Management of Perimenopausal Insomnia: A Systematic Review and Meta-Analysis

Background

Many women with perimenopausal insomnia (PMI) have sought alternative therapies such as acupuncture because of concerns about risks associated with hormone replacement therapy (HRT) and/or psychotropic drugs. This systematic review aimed to clarify if acupuncture alone or combined with standard Western pharmacotherapy (HRT and/or psychotropic drugs) is more effective in ameliorating PMI in comparison to pharmacotherapy alone.

Methods

Randomized controlled trials (RCTs) of PMI treatment via acupuncture alone or combined with Western pharmacotherapy versus Western pharmacotherapy were searched for from eleven databases from inception to March 2020. Cochrane criteria were followed.

Results

Fifteen studies involving 1410 women were analyzed. Meta-analysis indicated that acupuncture significantly reduced the global scores of Pittsburgh Sleep Quality Index (PSQI) [MD = −2.38, 95% CI (−3.38, −1.37), p < 0.01] and Kupperman Index [MD = −5.95, 95% CI (−10.68, −1.21), p = 0.01], compared with hypnotics. Acupuncture combined with hypnotics was more effective than hypnotics alone in decreasing PSQI scores [MD = −3.13, 95% CI (−5.43, −0.83), p < 0.01]. Too few RCTs were available to investigate the clinical efficacy differences between acupuncture and HRT/psychotropic drugs other than hypnotics.

Conclusions

Despite limited evidence, in comparison to hypnotics, acupuncture was associated with significant improvements in PMI, and reductions of other menopausal symptoms. This finding suggests that acupuncture may be a useful addition to treatment for PMI.

Minimizing Venous Thromboembolism in Feminizing Hormone Therapy: Applying Lessons From Cisgender Women and Previous Data

OBJECTIVE

To review he impact of estrogen-containing feminizing hormone regimens on transgender individuals' risk for VTE.

METHODS

We evaluated VTE risk by screening 1170 relevant studies published from 1994 to 2020, focusing on meta-analysis data.

RESULTS

The type of oral estrogen, route of administration, patient demographics, and comorbidities may affect the risk of VTE. Venous thrombosis is the most common vascular complication associated with HT.

CONCLUSION

Conjugated equine estrogens and 17-β estradiol appear to be safer than oral ethinyl estradiol. Transdermal estrogen formulations appear to be the least thrombogenic estrogens. Estrogens used concomitantly with progestins increase the risk of VTE compared to estrogens alone. To date, there are no data to demonstrate the benefit of holding HT prior to vaginoplasty or other gender affirming surgeries. For most young, healthy transgender women, there is little risk of VTE with HT, while older patients with risk factors should be discussed case by case.

Stroke in SARS-CoV-2 Infection: A Pictorial Overview of the Pathoetiology

Since the early days of the pandemic, there have been several reports of cerebrovascular complications during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Numerous studies proposed a role for SARS-CoV-2 in igniting stroke. In this review, we focused on the pathoetiology of stroke among the infected patients. We pictured the results of the SARS-CoV-2 invasion to the central nervous system (CNS) via neuronal and hematogenous routes, in addition to viral infection in peripheral tissues with extensive crosstalk with the CNS. SARS-CoV-2 infection results in pro-inflammatory cytokine and chemokine release and activation of the immune system, COVID-19-associated coagulopathy, endotheliitis and vasculitis, hypoxia, imbalance in the renin-angiotensin system, and cardiovascular complications that all may lead to the incidence of stroke. Critically ill patients, those with pre-existing comorbidities and patients taking certain medications, such as drugs with elevated risk for arrhythmia or thrombophilia, are more susceptible to a stroke after SARS-CoV-2 infection. By providing a pictorial narrative review, we illustrated these associations in detail to broaden the scope of our understanding of stroke in SARS-CoV-2-infected patients. We also discussed the role of antiplatelets and anticoagulants for stroke prevention and the need for a personalized approach among patients with SARS-CoV-2 infection.

Acupuncture as an Independent or Adjuvant Management to Standard Care for Perimenopausal Depression: A Systematic Review and Meta-Analysis

Background: Many women with perimenopausal depression (PMD) have sought alternative therapies such as acupuncture because of concerns about risks associated with antidepressant and hormone replacement therapy (HRT). This systematic review aimed to clarify if acupuncture is effective for PMD compared with waitlist control or placebo/sham acupuncture, and if acupuncture alone or combined with standard care (antidepressant and/or HRT) is more effective in ameliorating PMD in comparison with standard care alone. Methods: Randomized controlled trials (RCTs) of PMD treatment via acupuncture vs. waitlist control or placebo/sham acupuncture, and RCTs of PMD treatment via acupuncture alone or combined with Western pharmacotherapy vs. Western pharmacotherapy were searched for from seven databases from inception to December 2020. Cochrane criteria were followed. Results: Twenty-five studies involving 2,213 women were analyzed. Meta-analyses indicated that acupuncture significantly reduced the global scores of Hamilton Depression Scale (HAMD) [standardized mean difference (SMD) = -0.54, 95% CI (-0.91, -0.16), p < 0.01], compared with standard care. The therapeutic effect of acupuncture maintained at 2-, 4-, and 12-week follow-ups. Acupuncture combined with standard care was more effective than standard care alone in decreasing HAMD scores [SMD = -0.82, 95% CI (-1.07, -0.58), p < 0.01]. Too few RCTs were available to assess the clinical efficacy differences between acupuncture and placebo/sham acupuncture or HRT alone. Acupuncture also showed better effects in decreasing Kupperman index (KI) scores, whether compared with antidepressant alone [MD = -4.55, 95% CI (-8.46, -0.65), p = 0.02] or antidepressant combined with HRT [MD = -0.89, 95% CI (-1.34, -0.43), p < 0.01]. Conclusions: In comparison with standard care, acupuncture alone or combined with standard care was associated with significant improvements in PMD and reductions of other menopausal symptoms. This finding suggests that acupuncture may be a useful addition to treatment for PMD.

Estrogen and thrombosis: A bench to bedside review

Estrogen, in the clinical setting is used primarily for contraception and hormone replacement therapy. It has been well established that estrogen increases the risk of both arterial and venous thrombosis. While estrogen is known to induce a prothrombotic milieu through various effects on the hemostatic pathways, the exact molecular mechanism leading to those effects is not known. The most common clinical presentation of estrogen-related thrombosis is venous thromboembolism (VTE) of the deep veins of the legs or pulmonary vessels, usually within the first few months of use. Estrogen has also been associated with increased risk of "unusual site" thromboses, as well as arterial thrombosis. Women at high-risk of thrombosis need careful evaluation and counseling for contraception, pregnancy, menopausal hormonal therapy and other estrogen-related conditions or treatments in order to lower the risk of thromboses. We review the most recent evidence on management of high-estrogen states in women at high-risk of thrombosis, as well as emerging data on unique populations such as transgender women. More studies are needed to better understand the pathophysiology of hormone-related thrombosis, as well as more comprehensive techniques to stratify risks for thrombosis so as to enable tailoring of recommendations for each individual.

Managing the risk of venous thromboembolism in transgender adults undergoing hormone therapy

Introduction: Venous thromboembolism (VTE) is a potential risk of estrogen therapy. However, data show an improvement in the quality of life for transgender people who use feminizing hormone therapy. With few transgender-specific data, guidance may be drawn from cisgender (nontransgender) data, with a focus on hormonal birth control and postmenopausal hormone replacement therapy (HRT). The aim of this review is to examine the degree to which routes of administration, patient comorbidities, and type of hormone utilized affect the safety of estrogen therapy. Methods: We identified 6,349 studies by searching PubMed with the terms "transgender", "estrogen", "VTE", and "HRT". Of these, there were only 13 studies between 1989 and 2018 that investigated the effects of hormone therapy, including types of estrogens used, in transgender women and men. Results: The data suggest that the route of hormone administration, patient demographics, and patient comorbidities all affect estrogen's link with VTE. For example, avoiding ethinyl estradiol might make the use of hormone therapy in trans feminine individuals safer than oral birth control. Data from both cis and trans groups suggest additional VTE risk associated with the use of progestins. While transdermal estrogens dosed up to 0.1 mg/day or below appear lower risk for VTE than other forms of estrogen, it is unclear whether this is related to the delivery method or a dose effect. Finally, even if the risk from exogenous estrogen use remains significant statistically, the absolute clinical risk remains low. Conclusion: Clinicians should avoid the use of ethinyl estradiol. Additionally, data suggest that progestins should be avoided for transgender individuals. Further study of the relationship between estrogen use and the risk of VTE will serve to inform the safest care strategies for transgender individuals.

Update on the Cardiovascular Risks of Hormone Replacement Therapy

Systematic reviews of randomized, controlled trials have shown that use of hormone replacement therapy in women increases the risk of total cardiovascular disease (venous thromboembolism, stroke and coronary heart disease; there may also be an increased risk of peripheral arterial disease). The relative increase in risk is similar to that for use of combined oral contraceptives, but the absolute increase in risk is higher owing to the higher age of hormone replacement therapy users. The increased risk appears confined to current users, increases with age and obesity, and may differ with type of preparation. Transdermal hormone replacement therapy may carry a lower risk of venous thromboembolism compared with oral hormone replacement therapy. The mechanism for the increased risk is probably activated blood coagulation. The risk of venous thromboembolism is higher in women with thrombophilias; however, the value of screening for thrombophilias is not established. Further research is required to establish the risks of cardiovascular (and other) diseases in different groups of women for different types of hormone replacement therapy, including an individual participant meta-analysis of reported randomized, controlled trials.

Drug-Induced Thrombosis—Experimental, Clinical, and Mechanistic Considerations

Awareness of the dangers of drug-induced thrombosis has recently been heightened and led to demand for improved testing methodology. For example, reports indicating that some selective inhibitors of cyclooxygenase-2 (COX-2) increase the risk of myocardial infarction and atherothrombotic events caused the withdrawal of rofecoxib from global markets and the issuance of warnings concerning the usage of other COX-2 inhibitors. Drugs may exert a prothrombotic state by a variety of mechanisms–those affecting the vessel wall, the blood flow, and/or different blood constituents. Our review serves as an update to that of Gerhard Zbinden published in 1976 by presenting recently acquired data that more fully elucidate the different mechanisms by which drugs are believed to induce thrombogenic effects and discussing new methods used to detect these without losing sight of the classical pathology of thrombosis. We offer correlations between experimental findings and clinical data and conclude that, because drugs may induce a prothrombotic state by a variety of mechanisms, they should be tested for these using appropriate experimental methods and animal models.

Abnormalities in three-dimensional capillary architecture and imbalance between vascular endothelial growth factor-A and thrombospondin-1 in soleus muscle of ovariectomized rat

Reduced ovarian hormone levels associated with menopause or ovariectomy (OVX) not only result in vascular dysfunction but also lead to structural abnormalities in capillaries. Therefore, the effect of OVX on the three-dimensional (3-D) architecture of capillary networks and the underlying molecular mechanisms were investigated in rat soleus muscle. Seven-week-old female Wistar rats were divided into the OVX and sham-treated (Sham) groups. The OVX group exhibited lower endurance exercise capacity compared to the sham group and resulted in decreased capillary diameter, number of anastomoses and capillary/anastomosis volume in soleus muscle, indicating 3-D structural abnormalities of capillary networks. Furthermore, OVX led to increased concentrations of thrombospondin-1 (TSP-1) protein and a decreased VEGF-A/TSP-1 ratio, an indicator of angio-adaptations, in soleus muscle compared with the Sham group. These results indicate OVX may induce 3-D capillary regression in soleus muscle through an imbalance between VEGF-A and TSP-1 expression, possibly associated with decreased exercise tolerance in ovariectomized rats.

A Novel, Stable, Estradiol-Stimulating, Osteogenic Yam Protein with Potential for the Treatment of Menopausal Syndrome

A novel protein, designated as DOI, isolated from the Chinese yam (Dioscorea opposita Thunb.) could be the first protein drug for the treatment of menopausal syndrome and an alternative to hormone replacement therapy (HRT), which is known to have undesirable side effects. DOI is an acid- and thermo-stable protein with a distinctive N-terminal sequence Gly-Ile-Gly-Lys-Ile-Thr-Thr-Tyr-Trp-Gly-Gln-Tyr-Ser-Asp-Glu-Pro-Ser-Leu-Thr-Glu. DOI was found to stimulate estradiol biosynthesis in rat ovarian granulosa cells; induce estradiol and progesterone secretion in 16- to 18-month-old female Sprague Dawley rats by upregulating expressions of follicle-stimulating hormone receptor and ovarian aromatase; counteract the progression of osteoporosis and augment bone mineral density; and improve cognitive functioning by upregulating protein expressions of brain-derived neurotrophic factor and TrkB receptors in the prefrontal cortex. Furthermore, DOI did not stimulate the proliferation of breast cancer and ovarian cancer cells, which suggest it could be a more efficacious and safer alternative to HRT.

Perspective on prescribing conjugated estrogens/bazedoxifene for estrogen-deficiency symptoms of menopause: a practical guide

Current guidelines recommend that hormone therapy (HT) in postmenopausal women with a uterus include a progestin to protect against endometrial hyperplasia. However, many concerns relating to HT use appear to be related to the progestin component, including cardiovascular risk, breast stimulation, and irregular vaginal bleeding. Conjugated estrogens (CE) combined with the selective estrogen receptor modulator bazedoxifene (BZA) is a new progestin-free HT option for alleviating estrogen deficiency symptoms in postmenopausal women with a uterus for whom treatment with progestin-containing therapy is not appropriate. Five double-blind, randomized, placebo-controlled, phase 3 studies, known as the Selective estrogens, Menopause, And Response to Therapy (SMART) trials have investigated the efficacy of CE/BZA for relieving vasomotor symptoms (VMS), and effect on bone mass, as well as endometrial and breast safety in postmenopausal women. In a 12-week study, CE 0.45 mg/BZA 20 mg significantly reduced the number and severity of hot flushes compared with placebo at weeks 4 and 12. Unlike estrogen-progestin therapy (EPT), CE 0.45 mg/BZA 20 mg did not increase breast density compared with placebo. In clinical trials up to 2 years, CE/BZA had a favorable tolerability profile, demonstrated by amenorrhea rates similar to placebo. Vascular disorders including venous thromboembolic events (pulmonary embolism, retinal vein thrombosis, deep vein thrombosis, and thrombophlebitis) were rare events, occurring in less than 1 per 1000 patients. CE/BZA was associated with significantly higher incidences of amenorrhea and lower incidences of bleeding compared with CE/medroxyprogesterone acetate in 2 comparative trials. Therefore, CE 0.45 mg/BZA 20mg provides an effective, well-tolerated, progestin-free alternative to EPT for postmenopausal women with a uterus.

Germinated brown rice and its bioactives modulate the activity of uterine cells in oophorectomised rats as evidenced by gross cytohistological and immunohistochemical changes

Background

Germinated brown rice (GBR) is gaining momentum in the area of biomedical research due to its increased use as a nutraceutical for the management of diseases. The effect of GBR on the reproductive organs of oophorectomised rats was studied using the gross, cytological, histological and immunohistochemical changes, with the aim of reducing atrophy and dryness of the genital organs in menopause.

Methods

Experimental rats were divided into eight groups of six rats per group. Groups 1, 2 and 3 (sham-operated (SH), oophorectomised without treatment (OVX) and oophorectomised treated with 0.2 mg/kg oestrogen, respectively) served as the controls. The groups 4,5,6,7 and 8 were treated with 20 mg/kg Remifemin, 200 mg/kg of GBR, ASG, oryzanol and GABA, respectively. All treatments were administered orally, once daily for 8 weeks. Vaginal smear cytology was done at the 7^th week on all the rats. The weight and dimensions of the uterus and vagina were determined after sacrifice of the rats. Uterine and vaginal tissues were taken for histology and Immunohistochemical examinations.

Results

GBR and its bioactives treated groups significantly increased the weight and length of both the uterus and the vagina when compared to Oophorectomised non-treated group (OVX-non-treated) (p < 0.05). Significant changes were observed in the ratio of cornified epithelial cells and number of leucocytes in the vaginal cytology between the oophorectomised non-treated and treated groups. There was also an increase in the luminal and glandular epithelial cells activity in the treated compared with the untreated groups histologically. Immunohistochemical staining showed specific proliferating cell nuclear antigen (PCNA) in the luminal and glandular epithelium of the treated groups, which was absent in the OVX-non-treated group. GBR improved the length and weight of the uterus and also increased the number of glandular and luminal cells epithelia of the vagina.

Conclusion

GBR and its bioactives could be a potential alternative in improving reproductive system atrophy, dryness and discomfort during menopause.

Increased C-reactive protein levels in overweight and obese women taking exogenous hormones: the United Kingdom Women's Heart Study (UKWHS)

OBJECTIVE

Women's cardiovascular risk factors, including inflammatory markers such as C-reactive protein (CRP) which is emerging as a major association with cardiovascular disease (CVD) risk, can be influenced by the oral contraceptive (OC) pill in premenopausal and hormone replacement (HR) in postmenopausal women and by central adiposity which is associated with a heightened inflammatory state. The interaction between central obesity and different hormone use in both pre and postmenopausal women has not previously been reported in a study spanning the whole age range associated with hormone use.

DESIGN

Observational, cross-sectional study.

PATIENTS

Only healthy women were included in this study.

MEASUREMENTS

A total of 21,310 women aged 30-64 employed by Marks & Spencer participated. They completed a health questionnaire and were screened for CVD risk factors including blood pressure, weight, height, waist and hip circumference, lipids and lipoproteins, CRP and fibrinogen.

RESULTS

Compared with non-users, women who took the OC or HR had significantly higher CRP levels. This was more marked than effects on other CVD risk factors. It was further compounded by the independent effect of increased waist circumference. The CRP increase was greatest (more than twice that of nonhormone users) in premenopausal women with the highest quartile of waist circumference who took the combined contraceptive pill.

CONCLUSIONS

Women who received first the combined OC and then HR may be exposed over much of their life to high CRP levels aggravated by central obesity. The health consequences of this require further investigation.

Mechanisms of thrombosis related to hormone therapy

Combined oral contraceptives and combined oral postmenopausal hormone therapy are associated with a weak, but clinically significant risk of arterial and venous thrombosis (VT). The effects are related to dose of estrogen and type of progestin. The main effects are increase in markers of activated coagulation, reduction in coagulation inhibitors, and acquired activated protein C resistance. Reduction in tissue factor pathway inhibitor (TFPI) is probably an important mechanism, which predicts activation of coagulation and acquired resistance to activated protein C. Coagulation markers should be used as intermediate or surrogate markers in early pharmacodynamic studies to evaluate the risk associated with new formulations.

Hormone replacement therapy and risk of venous thromboembolism in postmenopausal women: systematic review and meta-analysis

OBJECTIVE

To assess the risk of venous thromboembolism in women using hormone replacement therapy by study design, characteristics of the therapy and venous thromboembolism, and clinical background.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline.

STUDIES REVIEWED

Eight observational studies and nine randomised controlled trials.

INCLUSION CRITERIA

Studies on hormone replacement therapy that reported venous thromboembolism. REVIEW MEASURES: Homogeneity between studies was analysed using chi(2) and I(2) statistics. Overall risk of venous thromboembolism was assessed from a fixed effects or random effects model.

RESULTS

Meta-analysis of observational studies showed that oral oestrogen but not transdermal oestrogen increased the risk of venous thromboembolism. Compared with non-users of oestrogen, the odds ratio of first time venous thromboembolism in current users of oral oestrogen was 2.5 (95% confidence interval 1.9 to 3.4) and in current users of transdermal oestrogen was 1.2 (0.9 to 1.7). Past users of oral oestrogen had a similar risk of venous thromboembolism to never users. The risk of venous thromboembolism in women using oral oestrogen was higher in the first year of treatment (4.0, 2.9 to 5.7) compared with treatment for more than one year (2.1, 1.3 to 3.8; P<0.05). No noticeable difference in the risk of venous thromboembolism was observed between unopposed oral oestrogen (2.2, 1.6 to 3.0) and opposed oral oestrogen (2.6, 2.0 to 3.2). Results from nine randomised controlled trials confirmed the increased risk of venous thromboembolism among women using oral oestrogen (2.1, 1.4 to 3.1). The combination of oral oestrogen and thrombogenic mutations or obesity further enhanced the risk of venous thromboembolism, whereas transdermal oestrogen did not seem to confer additional risk in women at high risk of venous thromboembolism.

CONCLUSION

Oral oestrogen increases the risk of venous thromboembolism, especially during the first year of treatment. Transdermal oestrogen may be safer with respect to thrombotic risk. More data are required to investigate differences in risk across the wide variety of hormone regimens, especially the different types of progestogens.

Hormone therapy and thromboembolic disease

PURPOSE OF REVIEW

Hormone therapy increases the risk of venous thromboembolism (VTE). To reduce this risk, changes in dosage, composition and route of administration have been made over the years. This review provides a summary of the available evidence and an update on the most recent findings on the issue.

RECENT FINDINGS

Contraceptives containing third-generation progestagens confer a higher risk of VTE than second-generation compounds. Little data are available on preparations containing less than 30 micarog of estrogen, new progestagens or levonorgestrel-releasing intrauterine devices. Hormone replacement therapy increases the risk of VTE by 2 to 3-fold. Transdermal administration may be less thrombogenic than oral administration, while different estrogens and progestagens may carry a different risk. VTE risk is further increased in carriers of inherited thrombophilia. Despite a similar increase in relative risk of thrombosis associated with hormone therapy, absolute risk is lower in fertile women and higher in postmenopausal ones. Universal screening for thrombophilia before prescribing hormone replacement therapy might be cost-effective.

SUMMARY

Careful evaluation of individual risk factor is warranted before prescribing hormone therapy. Further investigations are needed to establish whether or not newer compounds are safer than older ones with respect to the risk of thrombosis.

Microvascular network remodeling in dura mater of ovariectomized pigs: role for angiopoietin-1 in estrogen-dependent control of vascular stability

Estrogen is a key regulator of vascular responses and angioadaptation in multiple organs and tissues, including brain. However, the consequences of a loss of ovarian steroid hormone secretion on the status of microvascular networks in brain and meninges are largely unknown. Here, using the perfused dura mater model coupled with high-resolution digital epifluorescence and laser scanning confocal microscopy and computer-assisted morphometric analysis, we demonstrate that cessation of ovarian hormone production causes dramatic vascular remodeling in meningeal microvascular networks characterized by a threefold decrease in microvessel density and capillary rarefaction and an almost fourfold increase in vascular permeability. These changes were accompanied by a significant decrease in angiopoietin-1 (Ang-1) expression and Ang-1/Tie-2 ratio (1.4-fold, P < 0.01, and 1.5-fold, P < 0.05, respectively) in ovariectomized animals compared with intact females, but no changes were detected in the expression of estrogen receptors (ER)-alpha and -beta. We conclude that estrogen-dependent control of Ang-1 expression plays an important role in stabilizing meningeal microvessel and maintaining healthy microvascular networks.

A comparative study of the effect of continuous combined conjugated equine estrogen plus medroxyprogesterone acetate and tibolone on blood coagulability

BACKGROUND

Hormone therapy (HT) after the menopause is associated with increased risk of venous thromboembolism (VTE). Tibolone has pharmacodynamic properties different from other hormone preparations. We compared the effect of a combined HT and tibolone on the inhibition of haemostasis.

METHODS

Thirty-eight post-menopausal women were randomly assigned to 1.25 or 2.5 mg per day of tibolone or oral continuous combined conjugated equine estrogen plus medroxyprogesterone acetate (CEE/MPA). Inhibitors of haemostasis were measured at baseline and after 12 months.

RESULTS

Results from the two groups of women receiving tibolone were not significantly different and, to improve the power of the study, the two groups were merged. Higher concentration of protein S (1.16 versus 1.00 IU ml(-1); P = 0.005) and higher activated protein C resistance ratio (APC-R) (4.2 versus 3.65; P = 0.04) were observed in the tibolone group than in the CEE/MPA group. Both doses of tibolone increased APC-R significantly (P < 0.01). Tissue factor pathway inhibitor (TFPI) was lower in the CEE/MPA group than in the tibolone group (67.8 versus 79.9 ng ml(-1); P = 0.03). CEE/MPA reduced the concentration of antithrombin (P = 0.002), protein S (P < 0.001) and TFPI (P < 0.001). Both preparations reduced the concentration of plasminogen activator inhibitor 1 (P < 0.05).

CONCLUSIONS

Tibolone induces fewer pharmacological alterations on blood coagulability than CEE/MPA and has a potentially favourable effect on APC-R. This may translate into a corresponding low risk of VTE, as also indicated from the existing clinical data.

Differential effects of conventional and low dose oral hormone therapy (HT), tibolone, and raloxifene on coagulation and fibrinolysis

INTRODUCTION

We have recently reported that different hormone regimens given to healthy post-menopausal women had markedly different effects on activation of coagulation. Low-dose hormone therapy (HT) and raloxifene, as opposed to conventional-dose HT and tibolone, were associated with no or minor activation of coagulation. The aim of this study was to elucidate the mechanism(s) for differences in coagulation activation by analysing clotting and fibrinolytic factors and coagulation inhibitors.

MATERIALS AND METHODS

202 healthy women were randomly assigned to receive treatment for 12 weeks with either low dose HT containing 1 mg 17 beta-estradiol+0.5 mg norethisterone acetate (NETA) (n=50), conventional dose HT containing 2 mg 17 beta-estradiol and 1 mg NETA (n=50), 2.5 mg tibolone (n=51), or 60 mg raloxifene (n=51) in an open-label design.

RESULTS

The conventional-and low-dose HT groups generally showed similar effects, i.e., reductions in both clotting factors and inhibitors, but the effects were markedly more pronounced in the conventional-dose HT group. Compared with the low-dose HT group those treated with tibolone showed more pronounced decreases in factor VII, less reduction of antithrombin and protein C and even increased levels in protein S and tissue factor pathway inhibitor. As opposed to the low-dose HT group the reductions in inhibitors in the raloxifene group were smaller. Moreover in those allocated to raloxifene reduced levels of fibrinogen were seen.

CONCLUSIONS

Our study demonstrates that the different HT regimens and raloxifene exert differential effects on coagulation factors, inhibitors and fibrinolytic factors.

Conventional-dose hormone therapy (HT) and tibolone, but not low-dose HT and raloxifene, increase markers of activated coagulation

OBJECTIVES

Hormone therapy (HT) is associated with a modest, but significantly increased risk for arterial and venous thromboembolism. We have compared the effects of estrogen, tibolone, and raloxifene on relevant markers of coagulation activation and investigated whether there is a dose-response relationship of oral HT.

METHODS

Randomized, open-label, comparative study of 202 healthy women who were assigned to receive treatment for 12 weeks with either low-dose hormone therapy containing 1 mg 17beta-estradiol + 0.5 mg norethisterone acetate (NETA) (n=50), conventional-dose HT containing 2 mg 17beta-estradiol and 1 mg NETA (n=50), 2.5 mg tibolone (n=51), or 60 mg raloxifene (n=51).

RESULTS

The groups were comparable with regard to demographic characteristics and laboratory variables at baseline. D-dimer increased markedly in the conventional-dose HT group, but remained unchanged in the low-dose HT group. Tibolone was associated with a medium increase, whereas raloxifene was associated with a decrease in D-dimer levels. Changes in prothrombin fragment 1 + 2 showed a similar pattern for all four groups, whereas no significant differences in changes of thrombin-antithrombin complex were observed.

CONCLUSIONS

Our data suggest that low-dose HT is associated with less activation of coagulation than conventional-dose HT. This finding may be of clinical importance since randomized clinical trials showing increased risk of thrombosis have utilized conventional-dose HT.

Effects of daidzein, genistein, and 17beta-estradiol on 7,12-dimethylbenz[a]anthracene-induced mutagenicity and uterine dysplasia in ovariectomized rats

Phytoestrogens, primarily isoflavones daidzein (DZ) and genistein (GE), are increasingly used by postmenopausal women as an alternative to hormone replacement therapy due to reports that estrogen therapy increases the risk of breast and endometrial cancers. These compounds, as estrogen receptor agonists, may influence chemical carcinogenesis in estrogen-responsive tissues such as the uterus. We utilized ovariectomized (OVX) rats to model menopause and assessed the effects of dietary DZ, GE, or 17beta-estradiol (E2) on carcinogen-induced mutagenesis and carcinogenesis in the rat uterus. Big Blue transgenic rats (derived from Fischer 344 strain) were exposed to 7,12-dimethylbenz[a]anthracene (DMBA) in the presence or absence of the supplements. At 16- or 20-wk sacrifice, the uteri were removed and processed to determine mutant frequencies (MFs) and immunohistochemical or histopathological parameters, respectively. In rats treated with DMBA alone, a significant increase in lacI MFs (P < 0.01) in both OVX and intact (INT) rats was observed. The DMBA-induced MFs were not significantly altered by dietary DZ, GE, or E2 in both OVX and INT rats. Although dysplasia was not induced in the uterus of OVX and INT rats treated with DMBA alone, it was detected in 55% of OVX rats fed E2 alone and in 100% of OVX rats fed E2 along with DMBA exposure. Cell proliferation also was significantly higher in OVX rats fed E2 and treated with DMBA. In rats fed the isoflavones and treated with DMBA, the incidence of dysplasia was either reduced or virtually absent in both OVX and INT groups. These results indicate that a high incidence of dysplasia was associated with E2 feeding with or without DMBA treatment in the OVX rats, whereas the incidence was low in rats fed DZ or GE and treated with DMBA, suggesting a weak estrogen receptor agonist of DZ or GE in the rat uterus. The absence of dysplasia in OVX rats exposed to DMBA alone also suggests, in part, a promotional mechanism via estrogen- or isoflavone-driven cell proliferation.

Can haematological tests predict cardiovascular risk? The 2005 Kettle Lecture*

The risk of venous or arterial thrombosis is routinely assessed by clinical variables (risk factors) supplemented by measurement of blood lipids and glucose for arterial thrombotic events. Haematological tests that might play a role in risk prediction include haemostatic variables, haematocrit and inflammatory markers (erythrocyte sedimentation rate, plasma viscosity, white cell count). Recent epidemiological studies of these phenotypes and related genotypes are reviewed. For the risk prediction of first venous thrombosis, screening for thrombophilias in 'high-risk' situations does not appear clinically effective or cost-effective; with the possible exception of women considering oral hormone replacement therapy. General screening after a first venous event to predict recurrence (or risk in asymptomatic relatives) does not appear effective; with the possible exception of d-dimer, which requires further study. For risk prediction of first arterial thrombosis, screening adds little to prediction by current clinical risk scores. Screening of persons after a first arterial event, or with atrial fibrillation (e.g. with D-dimer for stroke prediction), requires further study. In conclusion, haematological tests have very limited roles in the prediction of cardiovascular risk, and should only be used according to evidence-based guidelines. The need for management studies is highlighted.

Seven haemostatic gene polymorphisms in coronary disease: meta-analysis of 66,155 cases and 91,307 controls

BACKGROUND

Variants of certain haemostatic genes (such as that encoding factor V Leiden) are involved in the development of venous thrombosis, but studies of such variants in coronary disease have reported apparently conflicting results. We did meta-analyses on seven such haemostatic genetic variants for which the available evidence on each comprises at least 5000 coronary disease cases and at least 5000 controls.

METHODS

Meta-analyses were done of 191 studies in relation to factor V G1691A (ie, factor V Leiden), factor VII G10976A, prothrombin G20210A, plasminogen activator inhibitor-1 (PAI-1) [-675] 4G/5G, and three platelet glycoprotein (GP) receptor variants (GPIa C807T, GPIbalpha T[-5]C, GPIIIa C1565T), involving a total of 66 155 coronary disease cases and 91 307 controls. We explored potential sources of heterogeneity.

FINDINGS

In a combined analysis of all studies, the per-allele relative risks (RR) for coronary disease of factor V 1691A and of prothrombin 20210A were 1.17 (95% CI 1.08-1.28) and 1.31 (1.12-1.52), respectively. Combined analyses of studies of the PAI-1 [-675] 4G variant yielded a per-allele relative risk for coronary disease of 1.06 (1.02-1.10), but there was an indication of publication bias in these studies. Combined analyses of the factor VII 10976A, GPIa 807T, GPIbalpha [-5]C, and GPIIIa 1565T variants showed no significant overall associations with coronary disease, yielding per-allele RRs of 0.97 (0.91-1.04), 1.02 (0.97-1.08), 1.05 (0.96-1.13), and 1.03 (0.98-1.07), respectively.

INTERPRETATION

The 1691A variant of the factor V gene and the 20210A variant of the prothrombin gene, both of which increase circulating thrombin generation, might each be moderately associated with the risk of coronary disease. Further studies are merited to assess these associations in greater detail (including any gene-gene and gene-environment interactions) and to determine any implications with regard to potential therapies designed to reverse patients' prothrombotic phenotype, such as selective plasma factor V or factor Xa inhibition.

Distribution and determinants of serum high-sensitive C-reactive protein in a population of young adults: The Cardiovascular Risk in Young Finns Study

OBJECTIVES

Elevated C-reactive protein (CRP) is a suggested risk marker for cardiovascular disease. We aimed at investigating the distribution and determinants of CRP levels in young adults.

DESIGN

Population-based study.

SUBJECTS

A total of 2,120 participants aged 24-39 years. Main outcome measures. Distribution of CRP, and the relationship between CRP and risk factors.

RESULTS

CRP concentration (mean+/-SD) was 1.43+/-3.26 mg L(-1) in men, 1.36+/-2.36 mg L(-1) in women who did not use oral contraceptives (OC) and 3.69+/-6.01 mg L(-1) in women who used OCs. In total, 8.8% of men, 10.3% of non-OC user women and 35.3% of OC user women had CRP concentration >3 mg L(-1) (recommended cut-off point of high risk for cardiovascular disease). In univariate analysis, CRP was associated with obesity indices and physical activity amongst both sexes. In men, the multivariate correlates of CRP included waist circumference (P<0.0001), smoking (<0.0001) and HDL cholesterol (P=0.024) (inverse association). These three variables explained 21.9% (model R(2)) of the total variation in CRP, waist circumference having the greatest influence (partial R(2)=19.6%). In women, the multivariate correlates of CRP included OC use (P<0.0001), body mass index (BMI) (P<0.0001), triglycerides (<0.0001) and physical activity (P=0.025) (inverse association). These four variables explained 38.2% (model R(2)) of the total variation in CRP, with OC use (partial R(2)=18.4%) and BMI (partial R(2)=18.0%) having the greatest influence.

CONCLUSIONS

The determinants of CRP level include obesity and smoking in men, and obesity, OC use and physical activity in women. About one in three of healthy women who use OCs have CRP concentration exceeding 3 mg L(-1).