Short- and long-term effects of hormone replacement therapy (transdermal estradiol vs oral conjugated equine estrogens, combined with medroxyprogesterone acetate) on blood coagulation factors in postmenopausal women

Are all estrogens created equal? A review of oral vs. transdermal therapy

BACKGROUND

To compare oral and transdermal delivery systems in domains of lipid effects; cardiovascular, inflammatory, and thrombotic effects; effect on insulin-like growth factor, insulin resistance, and metabolic syndrome; sexual effects; metabolic effects including weight; and effects on target organs bone, breast, and uterus.

METHODS

Review of the literature 1990-2010. Studies selected on basis of applicability, quality of data, and relationship to topic.

RESULTS

Data applicable to the comparisons of oral versus transdermal delivery systems for postmenopausal estrogen therapy were utilized to perform a review and formulate conclusions.

CONCLUSIONS

Significant differences appear to exist between oral and transdermal estrogens in terms of hormonal bioavailability and metabolism, with implications for clinical efficacy, potential side effects, and risk profile of different hormone therapy options, but neither results nor study designs are uniform. Bypassing hepatic metabolism appears to result in more stable serum estradiol levels without supraphysiologic concentrations in the liver. By avoiding first-pass metabolism, transdermal hormone therapy may have less pronounced effects on hepatic protein synthesis, such as inflammatory markers, markers of coagulation and fibrinolysis, and steroid binding proteins, while oral hormone therapy has more pronounced hyper-coagulant effects and increases synthesis of C-reactive protein and fibrinolytic markers. Both oral and transdermal delivery systems have beneficial effects on high-density lipoprotein cholesterol to low-density lipoprotein cholesterol ratios (oral>transdermal), while the transdermal system has more favorable effects on triglycerides. Incidence of metabolic syndrome and weight gain appears to be slightly lower with a transdermal delivery system. Oral estrogen's significant increase in hepatic sex hormone binding globulin production lowers testosterone availability compared with transdermal delivery, with clinically relevant effects on sexual vigor.

Effects of isoflavones on the coagulation and fibrinolytic system of postmenopausal women

OBJECTIVE

We evaluated the effects of soy isoflavone supplementation on hemostasis in healthy postmenopausal women.

METHODS

In this double-blinded, placebo-controlled study, 47 postmenopausal women 47-66 y of age received 40 mg of soy isoflavone (n = 25) or 40 mg of casein placebo (n = 22) once a day for 6 mo. Levels of factors VII and X, fibrinogen, thrombin-antithrombin complex, prothrombin fragments 1 plus 2, antithrombin, protein C, total and free protein S, plasminogen, plasminogen activator inhibitor-1, and D-dimers were measured at baseline and 6 mo. Urinary isoflavone concentrations (genistein and daidzein) were measured as a marker of compliance and absorption using high-performance liquid chromatography. Baseline characteristics were compared by unpaired Student's t test. Within-group changes and comparison between the isoflavone and casein placebo groups were determined by a mixed effects model.

RESULTS

The levels of hemostatic variables did not change significantly throughout the study in the isoflavone group; however, the isoflavone group showed a statistically significant reduction in plasma concentration of prothrombin fragments 1 plus 2; both groups showed a statistically significant reduction in antithrombin, protein C, and free protein S levels. A significant increase in D-dimers was observed only in the isoflavone group. Plasminogen activator inhibitor-1 levels increased significantly in the placebo group. However, these changes were not statistically different between groups.

CONCLUSION

The results of the present study do not support a biologically significant estrogenic effect of soy isoflavone on coagulation and fibrinolysis in postmenopausal women. However, further research will be necessary to definitively assess the safety and efficacy of isoflavone.

Comparison of the effects of tibolone and estrogen therapy on hemostasis in surgical menopause: a randomized, double-blind, placebo-controlled study

OBJECTIVE

To examine the effects of unopposed estrogen (E) and tibolone therapy on coagulation and natural anticoagulant systems in surgical menopause.

DESIGN

A randomized, double-blind, placebo-controlled study.

SETTING

University hospital clinic in Turkey.

PATIENT(S)

Ninety healthy surgically postmenopausal women.

INTERVENTION(S)

Ninety surgically postmenopausal women were randomized into three groups: unopposed conjugated ET (0.625 mg/d, group 1), tibolone (2.5 mg/d, group 2), and identical tablets of placebo (group 3).

MAIN OUTCOME MEASURE(S)

Effects on parameters in the clotting cascade at baseline and after 24 weeks of treatment.

RESULT(S)

After 6 months, fibrinogen, lipoprotein (a), and factor VIIa were decreased, and activated partial thromboplastin time was increased significantly in the ET group compared with in the placebo group. However, tibolone significantly decreased only the serum levels of factor VIIa and factor IX and prolonged the activated partial thromboplastin time, compared with placebo group. In addition, conjugated ET caused a significantly greater decrease in serum fibrinogen level than did tibolone.

CONCLUSION(S)

Neither E nor tibolone therapy led to activation of coagulation in the surgically menopausal women. Both preparations changed the overall hemostatic balance to a more fibrinolytic state.

Estrogen treatment improves arterial distensibility, fibrinolysis, and metabolic profile in postmenopausal women with type 2 diabetes mellitus

The effects of isolated estrogen therapy on the hemostatic system and arterial distensibility were determined in postmenopausal females with type 2 diabetes mellitus. This was a prospective nonrandomized study of 19 subjects (age, 56.2 +/- 4.7 years; body mass index, 27.8 +/- 2.4 kg/m(2) [mean +/- SD]). Inclusion was done after 2 months of glycemic and blood pressure control. The study consisted of 4 months of placebo treatment immediately followed by an equal period of oral conjugated equine estrogens (CEE) 0.625 mg/d. Measures included anthropometrics, a metabolic profile (oral glucose tolerance test and fasting glycated hemoglobin, total cholesterol and fractions, and triglyceride levels), and coagulation and fibrinolytic factors at the end of the placebo period and after 4 months of oral CEE. Conjugated equine estrogen therapy decreased plasminogen activator inhibitor 1 (placebo x CEE: 16.33 +/- 9.11 x 13.08 +/- 8.87 UI/mL, P < .03) and increased factor VIII activity (134.11% +/- 46.18% x 145.33% +/- 42.04%, P < .04). An increase in high-density lipoprotein cholesterol levels (placebo x CEE: 42.47 +/- 6.80 x 53.32 +/- 11.89 mg/dL, P < .01), and a decrease in glycated hemoglobin (8.45% +/- 1.30% vs 7.58% +/- 1.06%, P < .02) and in fasting glucose levels (121.51 +/- 21.05 x 111.21 +/- 20.74 mg/dL, P = .02) followed CEE therapy. Pulse wave velocity and augmentation index were performed by applanation tonometry and were obtained at the end of the placebo period (placebo), again after an intravenous load of 1.25 mg of CEE (short-term), and after 4 months of oral CEE (long-term). A significant decrease in central (carotid-femoral) pulse wave velocity was seen both after short- and long-term CEE (placebo vs short-term vs long-term: 9.36 +/- 2.58 vs 8.26 +/- 2.20 vs 7.98 +/- 1.90 m/s, respectively [analysis of variance, P < .03]; placebo vs short-term, P < .05; placebo vs long-term, P < .01), whereas augmentation index decreased only after long-term CEE (placebo vs short-term vs long-term: 39.14% +/- 6.94% vs 37.48% +/- 8.67% vs 34.3.3% +/- 8.11% [analysis of variance, P < .05], respectively; placebo vs long-term, P < .05). Long-term administration of CEE leads to an improvement in fibrinolysis and arterial distensibility, associated with an increase of the intrinsic coagulation pathway in postmenopausal women with type 2 diabetes mellitus.

Hormone replacement therapy, C-reactive protein, and fibrinogen in healthy postmenopausal women

OBJECTIVE

To investigate short-term and long-term effects of combined hormone replacement therapy (HRT) on C-reactive protein (CRP) and fibrinogen plasma concentrations in healthy postmenopausal women.

METHODS

In this cross-sectional study 241 healthy postmenopausal women were enrolled. A total of 81 women were receiving the following treatments for 3 months; transdermal 17beta-estradiol (17beta-E2) + medroxyprogesterone acetate (MPA) (n = 21), oral 17beta-E2 + norethisterone acetate (NETA) (n = 27), and conjugated equine estrogens (CEE) + MPA (n = 33). The same combined therapies were implemented in another 58 women for 12 months; transdermal 17beta-E2 + MPA (n = 10), oral 17beta-E2 + NETA (n = 16), and CEE + MPA (n = 32). Control group included 102 healthy postmenopausal women not receiving HRT. The effect of the type and the duration of HRT regimens on plasma levels of CRP, fibrinogen and lipids were investigated.

RESULTS

Median CRP concentrations were significantly higher in women receiving oral 17beta-E2 + NETA (P = 0.037) and CEE + MPA (P = 0.0001) for 3 months than in women taking the same types of HRT for 12 months and of those were not on HRT. Median CRP levels were similar in women taking transdermal 17beta-E2 + MPA for 3 and 12 months, compared with controls. Fibrinogen levels were not different between nonusers and any group of HRT users.

CONCLUSIONS

These elevated levels of CRP, which appears very recently as a crucial marker for cardiovascular disease, may be responsible for the early increased cardiovascular risk after starting oral combined HRT. But this increased risk in the early period seems to decrease with long-term use. Transdermal 17beta-E2 + MPA had insignificant effect on CRP both in short-term or in long-term use.

Positive impact of hormone replacement therapy on the fibrinolytic system: a long-term randomized controlled study in healthy postmenopausal women

BACKGROUND

The mechanisms by which postmenopausal hormone replacement therapy (HRT) may influence risk of cardiovascular disease are still unclear. Impaired fibrinolytic function is associated with an enhanced risk of cardiovascular disease and therefore the effect of HRT on fibrinolysis may be of importance.

OBJECTIVES

To investigate the prolonged effect of HRT on the fibrinolytic system and to determine whether two common polymorphisms in the plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) genes modulate this effect.

METHODS

Healthy postmenopausal women (n = 248) were randomized to HRT (n = 122) or no substitution (n = 126) 5 years prior to investigation.

RESULTS

Significantly higher values of t-PA activity and lower values of PAI-1 activity and PAI-1 antigen were found in the HRT group compared with the control group. This effect was independent of smoking and without influence from the two common polymorphisms PAI-1 -675(4G/5G) and t-PA intron8ins311. Furthermore, no difference between opposed estrogen (with norethisterone acetate as the gestagen component) and unopposed estrogen therapy was found. Both an intention-to-treat and a per-protocol analysis were performed and similar results were obtained.

CONCLUSIONS

Long-term treatment with HRT in healthy postmenopausal women was found to be associated with a beneficial fibrinolytic profile. This effect was found independent of smoking status, opposed and unopposed estrogen therapy had equal effect, and no influence of the two common polymorphisms PAI-1-675(4G/5G) and t-PA intron8ins311 was found. This effect of HRT on fibrinolytic capacity may be one of the beneficial effects of HRT in relation to cardiovascular diseases.

Hormone replacement therapy and hypercoagulability. Results from the Prospective Collaborative Danish Climacteric Study

OBJECTIVE

To assess the influence of a variety of HRT regimens on the haemostatic balance using markers of fibrin turnover and inhibitors of coagulation.

DESIGN

An open randomised study allocating women to either a control group or five different HRT treatment groups.

SETTING

Gentofte Hospital, Hellerup, and Rigshospitalet, Copenhagen, Denmark.

POPULATION

One hundred and forty-nine postmenopausal women without previous venous thromboembolic disease.

METHODS

Prothrombin fragment 1+2 (F(1+2)), fibrin degradation products, antithrombin, protein C, total protein S and activated protein C-normalised ratio were measured at baseline and after 6 and 12 months of HRT in six groups of healthy postmenopausal women: (A). no HRT (reference group), (B). continuous oestradiol valerate (E(2)V) plus cyproterone acetate, (C). cyclic E(2)V plus cyproterone acetate, (D). continuous combined oestrogen (E(2)) plus norethindrone acetate, (E). E(2) combined with local delivery of levonorgestrel and (F). E(2)V plus medroxyprogesterone. HRT-induced changes in the concentration of inhibitors of coagulation and markers of fibrin turnover during 12 months of treatment.

RESULTS

Significant decreases of antithrombin and protein S were found in all treatment groups, of protein C in Groups C, D, E and F and of activated protein C-normalised ratio in Groups E and F. Fibrin degradation products increased after three months of treatment, whereas F(1+2) was persistently increased after three months in Group F. The cumulative response of antithrombin was significantly lower in Groups D, E and F than in the reference group. The cumulative response of protein S and activated protein C-normalised ratio was lower, whereas that of F(1+2) was significantly higher in Group F than in the reference group.

CONCLUSION

HRT reduces the inhibitory potential of coagulation significantly. The effect is related to the type of E(2)/progestin combination administered, but seems to be oestrogen-derived as the most pronounced effect is found with only quarterly progestin intake. Such procoagulant activity of HRT may well translate into clinical manifestations in thrombosis-prone individuals.

Hormone therapy and venous thromboembolism

Convincing data from randomized trials and observational studies have demonstrated a two- to threefold increased risk of venous thromboembolism (VTE) with the use of hormone replacement therapy (HRT) in post-menopausal women. This risk is highest in the first year of use, but an increased risk persists after the first year if HRT use is ongoing. The risk of VTE is increased for oral oestrogen alone, oral oestrogen combined with progestin and probably for transdermal HRT. There is an increase in both idiopathic and non-idiopathic VTE with HRT. Early evidence suggests an interaction of HRT with thrombophilic states such as the factor V Leiden mutation, resulting in a synergistic increase in the risk of VTE. There is also an increased risk of VTE with raloxifene and tamoxifen, but the effects of low-dose HRT and tibolone on VTE risk are less clear.

Oral conjugated equine estrogen increases plasma von Willebrand factor in postmenopausal women

OBJECTIVES

We sought to test whether one month of daily oral conjugated equine estrogen (CEE) or transdermal estradiol alters hemostatic factors in postmenopausal subjects.

BACKGROUND

Estrogen replacement therapy and hormonal replacement therapy (HRT) effect an early increase in cardiovascular events in postmenopausal women. Circulating plasma von Willebrand factor (vWF) antigen is a marker of generalized endothelial dysfunction and atherothrombosis.

METHODS

Thirty-eight healthy postmenopausal women (average 59 +/- 7 years) were randomized to receive daily oral CEE, 0.625 mg (n = 21); transdermal estradiol, 0.1 mg/day (n = 7); or oral placebo (n = 10) for one month. Blood samples were collected at baseline and after two weeks and four weeks of therapy for measurement of circulating plasma hormones, lipid concentrations, and hemostatic factors.

RESULTS

Oral CEE decreased total cholesterol (p < 0.01) and low-density lipoprotein cholesterol (p < 0.01), although it increased both triglycerides (p < 0.05) and high-density lipoprotein cholesterol (p < 0.01). Transdermal estradiol had no significant effect on lipids. Plasminogen activator inhibitor-1 antigen declined in both oral CEE and transdermal estradiol users, but did not achieve statistical significance. Fibrin D-dimer antigen did not vary significantly in any group. However, oral CEE users had a significant increase in vWF from baseline to four weeks (p < 0.03) and a decrease in tissue-type plasminogen activator antigen from baseline to four weeks (p < 0.004), which was significantly different from the change observed in the transdermal estradiol group (p < 0.05).

CONCLUSIONS

These data suggest that the oral CEE-mediated increase in plasma vWF may have clinical relevance given the early atherothrombotic effects of HRT in postmenopausal women.

Parameters of coagulant and fibrinolytic capacity and activity in postmenopausal women: within-subject variability

We have analyzed the within-subject variability of a battery of parameters of coagulant and fibrinolytic capacity and activity in postmenopausal women. We observed large differences in within-subject variability among the tests and have demonstrated how such data can be used to estimate the number of times a parameter must be measured to produce a statistically adequate sample.

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.

Comparison of transdermal and oral estrogen-progestin replacement therapy: effects on cardiovascular risk factors

OBJECTIVE

To determine the effects of oral and transdermal hormone replacement therapy on lipid profile and hemostatic factors in postmenopausal women.

DESIGN

Twenty subjects were treated with oral E2 valerate (2 mg) combined with cyproterone acetate (1 mg) (group I) and 21 with transdermal E2 (1.5 mg) plus oral medroxyprogesterone acetate (5 mg) (group II). The effects on lipid profile and hemostatic parameters were evaluated at baseline and after 3, 6, and 12 months of treatment.

RESULTS

Group I showed a stronger increase of high-density lipoprotein (HDL) cholesterol levels (2-8%) and stronger reduction of atherogenic indices (total cholesterol/HDL cholesterol and low-density lipoprotein/HDL cholesterol) than group II. Group II showed a more pronounced reduction of triglyceride (21-31%) and factor VII (6-10%) levels than group I. Both groups showed reduced concentrations of total cholesterol, low-density lipoprotein cholesterol, tissue plasminogen activator, plasminogen activator inhibitor-1, antithrombin III, and protein S, whereas protein C was increased after 12 months of treatment.

CONCLUSIONS

The cardioprotective effects of hormone replacement therapy are demonstrated by favorable effects on lipid profile and fibrinolytic activity. Oral hormone replacement therapy showed a more prominent effect on lipoprotein metabolism than did transdermal administration, but transdermal medication had a stronger effect on triglyceride and coagulation factors. However, it needs to be considered that there is an increased risk of venous thrombotic events in the first year of treatment.

Hormone replacement therapy in healthy postmenopausal women: a randomized, placebo-controlled study of effects on coagulation and fibrinolytic factors

OBJECTIVES

To evaluate effects of postmenopausal hormone replacement therapy (HRT) on von Willebrand factor, factor (F)VIII, factor (F)VII, fibrinogen, antithrombin (AT) III, prothrombin fragments 1 and 2, protein C, total and free protein S, plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA) and resistance to activated protein C.

DESIGN

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

SETTING

Department of Endocrinology, University Hospital, Malmö, Sweden.

SUBJECTS

Fifty-one postmenopausal women with a history of amenorrhoea of at least 6 months and body mass index > or = 24 kg m-2 participated in part 1 and 46 participated in part 2.

INTERVENTION

Randomization for 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

At baseline and after 3 and 12 months.

RESULTS

During 0-3 months in the HRT group, FVII increased (P < 0.01), whereas fibrinogen, AT III and total protein S all decreased (P < 0.001 for all). Changes in variables were expressed as Delta-values. After 3 months Delta-values differed between groups for fibrinogen (P < 0.05), AT III (P < 0.001), total protein S (P < 0.001), and PAI-1 (P < 0.001). During 0-12 months, fibrinogen, total protein S, tPA (P < 0.01 for all) and AT III (P < 0.05) decreased. In the control group, all variables were unchanged during the study, except for increases (P < 0.05) in total protein S after 3 and 12 months, and a decrease (P < 0.01) in FVIII after 12 months. After 12 months Delta-values differed for fibrinogen (P < 0.05), AT III (P < 0.05) and total protein S (P < 0.001).

CONCLUSIONS

Unopposed oestrogen substitution was associated with both potentially beneficial effects, such as decreases in fibrinogen, and potentially thrombogenic effects such as decreasing AT III and protein S and increasing FVII. During prolonged follow-up and addition of progesterone, differences between groups concerning FVII were attenuated. These data suggest that effects of HRT upon coagulation are most pronounced early after institution of unopposed treatment.

Effect of oral postmenopausal hormone replacement on progression of atherosclerosis : a randomized, controlled trial

-Postmenopausal hormone replacement therapy (HRT) is associated with low cardiovascular morbidity and mortality in epidemiological studies. Yet, no randomized trial has examined whether HRT is effective for prevention of coronary heart disease (CHD) in women with increased risk. The objective of this study was to determine whether HRT can slow progression of atherosclerosis, measured as intima-media thickness (IMT) in carotid arteries. Carotid IMT is an appropriate intermediate end point to investigate clinically relevant effects on atherogenesis. This randomized, controlled, observer-blind, clinical, single-center trial enrolled 321 healthy postmenopausal women with increased IMT in >/=1 segment of the carotid arteries. For a period of 48 weeks, subjects received either 1 mg/d 17ss-estradiol continuously plus 0.025 mg gestodene for 12 days every month (standard-progestin group), or 1 mg 17ss-estradiol plus 0.025 mg gestodene for 12 days every third month (low-progestin group), or no HRT. Maximum IMT in 6 carotid artery segments (common, bifurcation, and internal, both sides) was measured by B-mode ultrasound before and after intervention. HRT did not slow IMT progression in carotid arteries. Mean maximum IMT in the carotid arteries increased by 0.02+/-0.05 mm in the no HRT group and by 0.03+/-0.05 and 0.03+/-0.05 mm, respectively, in the HRT groups (P:>0.2). HRT significantly decreased LDL cholesterol, fibrinogen, and follicle-stimulating hormone. In conclusion, 1 year of HRT was not effective in slowing progression of subclinical atherosclerosis in postmenopausal women at increased risk.

Women's health care during the perimenopause

OBJECTIVE

To review the perimenopause, its associated symptoms, and current management options.

DATA SOURCES

Published articles identified through MEDLINE (1966-2000) using the search terms perimenopause and treatment. Additional articles and books were identified from the bibliographies of the retrieved articles.

DATA SYNTHESIS

The perimenopause is the transition period from normal ovulatory cycles to menopause. It is associated with erratic fluctuations in reproductive hormone levels, often leading to irregular menstrual cycles, vasomotor symptoms, changes in mood or cognition, and sexual dysfunction. The perimenopause is an ideal time to evaluate a woman's health risks for such common chronic midlife conditions as heart disease, osteoporosis, and some cancers, and to initiate appropriate preventive health measures. Low-dose oral contraceptives and other hormonal therapies are often effective in managing perimenopausal symptoms.

CONCLUSION

The transition to menopause is an important time in the female life span that is associated with varied physical and psychological symptoms. Pharmacists should be prepared to provide education about the perimenopause and counsel women on the benefits and risks of various pharmacologic and nonpharmacologic treatments that can ease their passage through this often difficult transition. Pharmacists also are well-positioned to educate and encourage perimenopausal women to initiate lifestyle changes that can enhance their health for the rest of their lives.

The effects of hormone replacement therapy on thrombin generation, fibrinolysis inhibition, and resistance to activated protein C: prospective cohort study and review of literature

Recent studies have found that hormone replacement therapy (HRT) is associated with a two- to fourfold increased risk of venous thromboembolism, but the thrombogenic mechanism of HRT remains unclear. To investigate whether HRT use induces a procoagulant state, we undertook a prospective cohort study in postmenopausal women to investigate the effects of 3 months of treatment with oral HRT (conjugated equine estrogen 0.625 mg daily and medroxyprogesterone 2.5 mg daily) on markers of thrombin generation (prothrombin fragment 1+2, thrombin-antithrombin complexes), fibrinolytic potential (plasminogen activator inhibitor-1 (PAI-1) activity), and activated protein C (APC) resistance. In addition, we reviewed the literature for studies investigating the effects of HRT on markers of thrombin generation and fibrinolytic potential. In 12 patients who received HRT for a mean of 3.8 months, there was no significant effect of HRT on levels of F1+2, thrombin-antithrombin complexes, or the APC ratio. HRT use had the greatest effect on PAI-1 activity (mean difference = -3.75 UI/mL; 95% confidence interval: - 8.9, 1.1) compared to other coagulation parameters, but this did not attain statistical significance (p = 0.12). In the literature review, the effects of HRT on markers of thrombin generation were inconsistent across studies. There was a consistent pattern of increased fibrinolytic potential with HRT use associated with one marker (PAI-1), but not with another marker (tissue plasminogen activator antigen). We conclude that there is a lack of consistent evidence that the increased risk of venous thromboembolism associated with HRT use is due to a procoagulant state related to increased thrombin generation, decreased fibrinolytic potential, or acquired APC resistance.

Effects of tibolone and continuous combined hormone replacement therapy on parameters in the clotting cascade: a multicenter, double-blind, randomized study

OBJECTIVE

To determine the effects of tibolone and continuous combined HRT (ccHRT) on parameters in the clotting cascade.

DESIGN

Randomized, double-blind study.

SETTING

Hemostasis unit of a university hospital clinic in Germany.

PATIENT(S)

Sixty healthy postmenopausal women.

INTERVENTION(S)

Twenty-nine subjects were treated with tibolone (2.5 mg/d) and 31 with oral ccHRT containing estradiol (2 mg/d) + estriol (1 mg/d) + norethindrone acetate (1 mg/d).

MAIN OUTCOME MEASURE(S)

Effects on parameters in the clotting cascade at baseline and after 12 and 24 weeks of treatment.

RESULT(S)

Tibolone increased fibrinolysis parameters without significantly altering coagulation parameters. Treatment with ccHRT resulted in a stimulating effect on parameters of both fibrinolysis and coagulation. Tibolone showed a stronger reduction of factor VII activity; less reduction of AT-III, protein C activity, and protein S activity; stronger increase of the activated partial thromboplastin time, plasminogen and plasminogen-antiplasminogen complexes; and less increase of D-Dimer than ccHRT. Both preparations similarly reduced climacteric complaints, whereas tibolone showed less breast complaints than ccHRT.

CONCLUSION(S)

This study confirms that tibolone, and to a lesser extent also ccHRT, changes hemostasis parameters toward a more fibrinolytic profile, which may diminish the risk of venous thrombosis.

Oral, but not transdermal, administration of estrogens lowers tissue-type plasminogen activator levels in humans without affecting endothelial synthesis

Oral estrogen administration decreases plasma levels of tissue-type plasminogen activator (tPA), which may be explained by a decrease in endothelial tPA synthesis, an increase in its hepatic clearance, or both. In the present study, we determined (1) differences between oral (ie, via the liver) ethinyl estradiol and transdermal (ie, systemic) 17beta-estradiol administration on plasma antigen levels of tPA and plasminogen activator inhibitor type-1 before and after 4 months of hormone administration and (2) effects on endothelial tPA synthesis, by measuring the local increase in plasma tPA during venous occlusion of the upper extremity. Thirty transsexual males (median age 32 years, range 20 to 44 years ) were randomly assigned to either oral ethinyl estradiol (n=15) or transdermal 17beta-estradiol (n=15); both treatments included the antiandrogen cyproterone acetate (CA). Ten males were treated with CA alone. Seventeen transsexual females (median age 27 years, range 18 to 37 years) were treated with intramuscular testosterone esters. Only oral ethinyl estradiol plus CA but neither transdermal 17beta-estradiol plus CA, nor oral CA, nor parenteral testosterone lowered plasma tPA and plasminogen activator inhibitor-1 (P<0.001 for both). tPA release during venous occlusion was not affected by oral ethinyl estradiol plus CA in males (P=0.52) or by parenteral testosterone in females (P=0.89). These data are consistent with a previous observation, in rodents, that the decrease in tPA after oral estrogen administration can be explained by an increase in hepatic tPA clearance, leaving endothelial tPA synthesis unchanged, and suggest that these mechanisms also explain the decrease in tPA in humans.

Influence of Contraceptive Pill Use, Premenopause and Postmenopausal State on Hemostatic Parameters in Ethnic Chinese Women

Background: Epidemiological studies has shown that increased fibrinogen and factor VIIc are two independent risk factors for cardiovascular disease (CVD). Postmenopausal women have a higher incidence of CVD than premenopausal women; one possible explanation is the increase of fibrinogen. Purpose: This study was undertaken to evaluate the influence of oral contraceptive pill use and postmenopausal status on coagulation factors in ethnic Chinese women. Patients and methods: This study included 1402 women aged 40-55 years, with 288 premenopausal women taking oral contraceptives and 364 postmenopausal women. All subjects underwent blood examination of prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIIc, factor VIIIc, plasminogen, and antithrombin III. Results: Data show that oral contraceptives users had a significant increase in plasminogen (91.7 +/- 40.7 vs. 80.0 +/- 26.5%; p < 0.01), while the levels of other hemostatic parameters were similar to non-contraceptive pill users. Postmenopausal women also had higher levels of plasminogen (113 +/- 36.2 vs. 108.7 +/- 30.7%; p = 0.06); the other parameters also show no statistical significance. Conclusions: Contrary to previous reports, which show elevation of fibrinogen and antithrombin III in menopause and in pill users, this study shows that only plasminogen levels exhibit a statistically significant contraceptive trend in Chinese women. Whether racial difference may account for the discrepancy in the present results needs further evaluation.

Effects of hormone replacement therapies on fibrinogen and plasma viscosity in postmenopausal women

In women, cardiovascular morbidity and mortality sharply increase after the onset of menopause. There is substantial evidence that hormone replacement therapy (HRT) may decrease the risk of coronary heart disease (CHD); however, the mechanisms of this preventive effect are unclear. We investigated the association between HRT and plasma viscosity as well as fibrinogen levels in postmenopausal women of a population-based sample (n=300, age 52-65 years). A total of 94 women used HRT; of these, 50 took oestrogen monotherapy and 44 used oestrogen-progesterone combinations. HRT was associated with significantly lower fibrinogen concentrations (2.32 v 2.68 g/l, P<0.001) and decreased plasma viscosity (1.147 v 1.176 mPa/s, P=0.01). Multivariate analyses controlling simultaneously for the effects of age, smoking, body mass index, and use of diuretics confirmed decreased fibrinogen and plasma viscosity values in women using HRT. A trend towards lower plasma viscosity (1.139 v 1.160 mPa/s) and plasma fibrinogen (2.28 v 2.44 g/l) was observed in women on oestrogen-progesterone combinations as compared with oestrogen monotherapy users: however, after controlling for the above-mentioned variables these differences were not statistically significant. This study demonstrates decreased plasma viscosity in women on HRT. Improved rheology offers a mechanism by which HRT lowers the risk of CHD in postmenopausal women.

Effects of hormone replacement therapy on cardiovascular risk factors in postmenopausal women

OBJECTIVE

To investigate changes in plasma lipoprotein profile, hemostatic factors, platelet aggregation, endothelin-1, and cardiac function during postmenopausal sequential 6-month hormone replacement therapy (HRT).

DESIGN

Open longitudinal prospective study.

SETTING

Gynecologic department of a medical center.

PATIENT(S)

Twenty-one healthy hysterectomized postmenopausal women.

INTERVENTION(S)

Oral E2 valerate (2 mg/d) combined with medroxyprogesterone acetate (MPA) (10 mg/d) during the last 10 days of each 21-day cycle. The treatment period was 6 months.

MAIN OUTCOME MEASURE(S)

Plasma lipoprotein profile, hemostatic parameters, platelet aggregation, endothelin-1, and left ventricular function.

RESULT(S)

After 6 months of treatment, total cholesterol, triglyceride, and low density lipoprotein (LDL) cholesterol were significantly progressively reduced. Atherogenic indices of total cholesterol-to-high-density lipoprotein (HDL) cholesterol and LDL-to-HDL cholesterols also showed a significant progressive decline. The concentrations of antithrombin III were significantly increased. The maximum aggregation and slope of platelet aggregation were significantly reduced, but all parameters were more pronounced at 1 month of HRT than at 3 or 6 months. The concentrations of endothelin-1 were significantly reduced (by 16.1%). In the evaluation of left ventricular function, only peak atrial diastolic velocity was significantly reduced.

CONCLUSION(S)

Combined HRT had favorable effects on lipids and lipoproteins, hemostatic factors, platelet aggregation, endothelin-1, and left ventricular function. However, further study is needed to evaluate the long-term effects of combined HRT, especially on platelet aggregation and cardiac function.

Effects of oral and transdermal estrogen/progesterone regimens on blood coagulation and fibrinolysis in postmenopausal women. A randomized controlled trial

Postmenopausal hormone replacement therapy is associated with a reduction in the incidence of coronary heart disease. However, inconclusive results have been reported with respect to the risk of stroke, and recent studies consistently showed an increased risk of venous thromboembolism in postmenopausal women using oral estrogen. There are surprisingly few interventional studies to assess the true effects of estrogen-progestin regimens on blood coagulation and fibrinolysis, and the impact of the route of estrogen administration on hemostasis has not been well documented. Therefore, we investigated the effects of oral and transdermal estradiol/progesterone replacement therapy on hemostatic variables. Forty-five healthy postmenopausal women, aged 45 to 64 years, were assigned randomly to one of the three following groups: cyclic oral or transdermal estradiol, both combined with progesterone, or no hormonal treatment. Hemostatic variables were assayed at baseline and after a 6-month period. Pairwise differences in the mean change between the three groups were compared using nonparametric tests. Oral but not transdermal estradiol regimen significantly increased the mean value of prothrombin activation peptide (F1 + 2) and decreased mean antithrombin activity compared with no treatment. Differences in fragment F1 + 2 levels between active treatments were significant. The oral estrogen group was associated with a significant decrease in both mean tissue-type plasminogen (t-PA) concentration and plasminogen activator inhibitor (PAI-1) activity and a significant rise in global fibrinolytic capacity (GFC) compared with the two other groups. A transdermal estrogen regimen had no significant effect on PAI-1, t-PA, and GFC levels. There were no significant changes in mean values of fibrinogen, factor VII, von Willebrand factor, protein C, fibrin D-dimer, and plasminogen between and within the three groups. We conclude that oral estrogen/progesterone replacement therapy may result in coagulation activation and increased fibrinolytic potential, whereas opposed transdermal estrogen appears without any substantial effects on hemostasis. Whereas these results may account for an increased risk of venous thromboembolism in users of oral postmenopausal estrogen, they emphasize the potential importance of the route of estrogen administration in prescribing hormone replacement therapy to postmenopausal women, especially to those at high risk of thrombotic disease.

Effects of estrogen replacement therapy on thrombin generation

The aim of this study was to investigate the hemostatic system in menopausal women before and after three months of treatment with transdermal estradiol (TTS 50, 50 micrograms/die, n = 13) or coniugated equine estrogen (CEE, 0.625 mg/die, n = 9) by evaluating : beta-thromboglobulin, platelet factor 4, factor VIIag, factor VIIc, fibrinopeptide A-FPA-, thrombin-antithrombin-TAT-complexes, antithrombin-AT-activity, protein C, plasma fibrinolytic activity (euglobulin clot lysis time), plasminogen and antiplasmin activity. FPA levels significantly increased during TTS 50 treatment (p < 0.001) while protein C showed a slight but significant decrease in both treatments (TTS 50 p < 0.001, CEE p < 0.05). TAT complexes and AT were found unaltered. Platelet function and fibrinolytic activity did not significantly change. A significant relationship between FPA and estradiol levels, which were significantly increased during. TTS 50 therapy, was found (r = 0.40, p < 0.05). These findings indicate that unopposed estradiol given by transdermal route induces a slight but significant blood clotting activation, which seems strictly related to its biological activity.

New developments in topical estrogen therapy

OBJECTIVE

To review new developments in transdermal E2 therapy in postmenopausal women.

DESIGN

A bibliographic search (Medline) of the medical literature from 1966 through 1995 was used to identify new studies evaluating transdermal E2.

PATIENT(S)

Menopausal and postmenopausal women.

RESULT(S)

Like oral estrogen, transdermal E2 relieves menopausal symptoms, reverses urogenital atrophy, and conserves bone economy. Initial studies have demonstrated beneficial effects of transdermal E2 on cardiovascular function. Quality of life, patient satisfaction, and compliance also improve with transdermal E2. Advances in transdermal delivery continue to emerge, including low-dose systems and patches that maintain serum E2 levels for a full 7-day period.

CONCLUSION(S)

New developments in transdermal administration have the potential to increase the number of postmenopausal women who accept and are compliant with long-term estrogen replacement therapy.

The effect of tamoxifen and hormone replacement therapy on serum cholesterol, bone mineral density and coagulation factors in healthy postmenopausal women participating in a randomised, controlled tamoxifen prevention study

BACKGROUND

The role of hormone replacement therapy (HRT) in women who have been treated for breast cancer remains controversial. The addition of tamoxifen may protect these women from any proliferative effect of exogenous oestrogen on the breast. The aim of this analysis was to determine if tamoxifen and HRT may be safely administered together.

METHODS

We studied the interaction between HRT and tamoxifen on serum cholesterol, fibrinogen, antithrombin III (AT III) and bone mineral density (BMD) in postmenopausal healthy women enrolled in a randomised tamoxifen chemoprevention trial.

RESULTS

Tamoxifen decreased serum cholesterol by a mean of 13% from pretreatment values (n = 153). The addition of HRT to tamoxifen did not result in further reduction in serum cholesterol (n = 20). HRT alone led to a reduction of serum cholesterol by a mean of 5% in 14 women on placebo. The addition of tamoxifen to HRT resulted in further reduction in serum cholesterol by a mean of 7% (n = 44). Significant reductions of plasma fibrinogen by 14% and AT III by 8% were seen in women who received tamoxifen. There were no further significant changes in these coagulation factors in women on tamoxifen/HRT combinations. Tamoxifen resulted in an annual increase in BMD of the femur and spine by 2% and 1.5%, respectively, when compared to placebo (n = 38). The addition of HRT to tamoxifen resulted in further 2% annual increase in BMD of the femur.

CONCLUSIONS

We conclude that there were no significant adverse intereactions with tamoxifen and HRT in this small series of patients. The combination results in a reduction of serum cholesterol, increase in BMD especially in the femur and appears not to have any adverse effect on coagulation factors. Multicentre studies should be conducted to evaluate the effect of this combination on relieving menopausal symptoms, disease relapse and overall survival in women who have received treatment for breast cancer.

Relation of hormone-replacement therapy to measures of plasma fibrinolytic activity. Atherosclerosis Risk in Communities (ARIC) Study Investigators

BACKGROUND

The mechanisms by which replacement hormones may reduce the risk of coronary heart disease are not fully understood. Of specific interest is a potential effect of replacement hormones on plasma fibrinolytic activity, a putative determinant of thrombotic events.

METHODS AND RESULTS

We investigated the relation of current use of replacement hormones to three measures of plasma fibrinolytic activity: tissue-type plasminogen activator (TPA) antigen, plasminogen activator inhibitor-1 (PAI-1) antigen, and D-dimer. The sample was composed of 288 women, free of clinical cardiovascular disease, who were selected for a case-control study of atherosclerosis: 142 women with ultrasonographic evidence of carotid intimal-medial thickening (cases) and 146 control subjects. Twenty percent (59 women) reported current use of replacement hormones. TPA antigen and PAI-1 antigen were highly correlated with each other (r = .67), whereas D-dimer correlated only weakly with TPA or PAI-1. Compared with nonusers, current users of replacement hormones had lower mean levels of TPA and PAI-1 antigens, suggesting enhanced fibrinolytic potential. In the entire sample, the multivariate-adjusted geometric mean values of TPA antigen were 6.3 and 7.3 ng/mL among current users and nonusers, respectively (P = .01); the corresponding values for PAI-1 antigen were 6.1 and 7.5 ng/mL (P = .13). These results were generally consistent for both atherosclerosis cases and their control subjects. D-dimer levels were lower in current hormone users than in nonusers, but the difference was not statistically significant (P > .15) in any of the analyses.

CONCLUSIONS

The use of replacement hormones appears to be associated with enhancement of endogenous fibrinolytic potential. Enhanced plasma fibrinolytic activity among hormone users may explain, in part, the inverse association between hormone replacement therapy and coronary heart disease.

The effect of estrogen replacement therapy with or without progestogen on the fibrinolytic system and coagulation inhibitors in postmenopausal status

OBJECTIVE

The aim of this study was to analyze several fibrinolytic components and coagulation inhibitors in postmenopausal women and had to evaluate the effect of hormone replacement therapy.

STUDY DESIGN

Several hemostatic parameters were evaluated in 75 postmenopausal women before and after 3 to 4 and 12 months of hormone therapy.

RESULTS

An increase in plasma fibrinolytic activity primarily related to a significant increase in tissue-type plasminogen activator and a decrease in plasminogen activator inhibitor type 1 was observed in women receiving hormone replacement therapy. A significant decrease in protein S and lipoprotein(a) was detected under therapy. No modifications in tissue-type plasminogen activator/plasminogen activator inhibitor-1 and activated protein C/alpha 1-antitrypsin complexes, urokinase activity, plasminogen, and antithrombin III were detected.

CONCLUSIONS

The increase in fibrinolytic activity and the decrease in lipoprotein(a) levels observed in women receiving hormone replacement therapy could help decrease the risk of coronary disease associated with the postmenopausal state.

Association of hormone replacement therapy with hemostatic and other cardiovascular risk factors. The FINRISK Hemostasis Study

The risk of cardiovascular diseases in women is small until menopause but increases considerably afterwards. When all age groups are considered, cardiovascular diseases are responsible for approximately half of the total mortality in women. It has been suggested that hormone replacement therapy (HRT) in perimenopausal and postmenopausal women could be useful in the prevention of cardiovascular diseases, but its effects are insufficiently known. We performed a cross-sectional study on the associations of menopause and HRT with cardiovascular risk factors, in particular with hemostatic factors, on female participants of the FINRISK Hemostasis Study. The participants, aged 45 to 64 years, were recruited from the Finnish population register by random sampling from three geographically defined areas. The participation rate of women was 83.2%. Of the 1202 women included in the study, 29.2% were current users of HRT. Differences in cardiovascular risk factors by menopausal status and by HRT use were examined after adjustment for age, study area, current smoking, body mass index, self-reported diabetes, and years of education. Postmenopausal women not using exogenous sex hormones had on average a total cholesterol level 0.5 mmol/L (8.9%) higher and an LDL cholesterol level 0.4 mmol/L (11.4%) higher than premenopausal women. Women reporting irregular menstruation (presumably due to perimenopause) had higher adjusted plasma fibrinogen, factor VII coagulant activity, and factor VII antigen than women with regular menstruation or no menstrual periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Associations of postmenopausal estrogen use with cardiovascular disease and its risk factors in older women. The CHS Collaborative Research Group

BACKGROUND

Postmenopausal estrogen replacement therapy has been associated with favorable levels of cardiovascular disease risk factors, but these associations and the relations between estrogen use and subclinical disease have not been examined in large samples of older women.

METHODS AND RESULTS

Present and past estrogen use was ascertained in 2955 women > or = 65 years old in the Cardiovascular Health Study, a study of risk factors for coronary heart disease and stroke in the elderly. Present estrogen use was reported by 12% of these women and past use by an additional 26.5%. Estrogen use (past or present) was strongly associated with lower low-density lipoprotein cholesterol, fibrinogen, glucose, insulin, obesity, and age and higher high-density lipoprotein cholesterol and socioeconomic status (all P < .0001). Estrogen users also had lower levels of subclinical disease as measured by carotid intimal-medial thickness, carotid stenosis grade, ECG left ventricular mass, and Doppler mitral peak flow velocities (each P < .02). Relations were similar in younger and older women (65 to 74 versus > or = 75 years) and smokers and nonsmokers and were unchanged after women with poor medication compliance were excluded. After adjustment for other factors, estrogen use was associated with decreased carotid wall thickness, although this association was of borderline significance after further adjustment for lipids.

CONCLUSIONS

Postmenopausal estrogen use in this sample of older women was associated with favorable cardiovascular disease risk factor profiles and with lower measures of subclinical disease. These findings suggest that postmenopausal estrogen use may be associated with lower risk of cardiovascular disease in women well into the eighth decade of life.

Haemostatic changes and thromboembolic risk during tamoxifen therapy in normal women

Tamoxifen has been implicated as a risk factor for venous thrombosis in advanced breast cancer although the evidence for increased arterial or venous thrombosis with tamoxifen in early breast cancer is less clear. The effect of tamoxifen on haemostasis, and thereby possible thromboembolic risk, was investigated in normal women enrolled in a placebo controlled trial of tamoxifen as a chemopreventative agent for breast cancer. There was an initial reduction in fibrinogen levels in all women on tamoxifen over the first year of follow-up and a marginal reduction in antithrombin III and Protein S in postmenopausal women at 6 months. There were no changes in cross linked fibrinogen degradation products or Protein C for pre or post-menopausal women. There was no increase in the incidence of thromboembolic events on tamoxifen. This study demonstrates that tamoxifen has only marginal effects on factors involved in haemostasis reported to affect the incidence of arterial or venous thromboembolic disease. The follow-up time is relatively short (maximum 36 months) and careful long term follow-up is necessary to detect clinically significant morbidity.