Significant differential effects of hormone therapy or tibolone on markers of cardiovascular disease in postmenopausal women: a randomized, double-blind, placebo-controlled, crossover study

The Effects of Menopause Hormone Therapy on Lipid Profile in Postmenopausal Women: A Systematic Review and Meta-Analysis

Importance: The incidence of dyslipidemia increases after menopause. Menopause hormone therapy (MHT) is recommended for menopause related disease. However, it is benefit for lipid profiles is inconclusive. Objective: To conduct a systematic review and meta-analysis of randomized controlled trials to evaluate the effects of MHT on lipid profile in postmenopausal women. Evidence Review: Related articles were searched on PubMed/Medline, EMBASE, Web of Science, and Cochrane Library databases from inception to December 2020. Data extraction and quality evaluation were performed independently by two reviewers. The methodological quality was assessed using the "Cochrane Risk of Bias checklist". Results: Seventy-three eligible studies were selected. The results showed that MHT significantly decreased the levels of TC (WMD: -0.43, 95% CI: -0.53 to -0.33), LDL-C (WMD: -0.47, 95% CI: -0.55 to -0.40) and LP (a) (WMD: -49.46, 95% CI: -64.27 to -34.64) compared with placebo or no treatment. Oral MHT led to a significantly higher TG compared with transdermal MHT (WMD: 0.12, 95% CI: 0.04-0.21). The benefits of low dose MHT on TG was also concluded when comparing with conventional-dose estrogen (WMD: -0.18, 95% CI: -0.32 to -0.03). The results also showed that conventional MHT significantly decreased LDL-C (WMD: -0.35, 95% CI: -0.50 to -0.19), but increase TG (WMD: 0.42, 95%CI: 0.18-0.65) compared with tibolone. When comparing with the different MHT regimens, estrogen (E) + progesterone (P) regimen significantly increased TC (WMD: 0.15, 95% CI: 0.09 to 0.20), LDL-C (WMD: 0.12, 95% CI: 0.07-0.17) and Lp(a) (WMD: 44.58, 95% CI:28.09-61.06) compared with estrogen alone. Conclusion and Relevance: MHT plays a positive role in lipid profile in postmenopausal women, meanwhile for women with hypertriglyceridemia, low doses or transdermal MHT or tibolone would be a safer choice. Moreover, E + P regimen might blunt the benefit of estrogen on the lipid profile. Clinical Trial Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42018092924], identifier [No. CRD42018092924].

Does tibolone treatment have favorable effects on obesity, blood pressure, and inflammation? A meta-analysis of randomized controlled trials

The clinical effects of tibolone on cardiometabolic markers are an underlying question in postmenopausal women. We aimed to meta-analyze the effects of tibolone on anthropometric indicators of obesity, blood pressure (BP), and on C-reactive protein (CRP) levels in postmenopausal women. Two independent reviewers searched Scopus, Web of Science, PubMed/Medline, and Embase up to until 20 April 2021. Weighted mean differences (WMDs) and 95% confidence interval (CI) were calculated through the DerSimonian and Laird random-effect models between the tibolone and the control groups. Data from 20 eligible included showed that tibolone treatment increased the body mass index (BMI) by 0.23 kg/m² (95% CI: 0.017 to 0.45, p = 0.03) but did not significantly increase body weight (WMD: 1.128 kg, 95% CI: -1.76 to 4.02, p = 0.44) or waist circumference (WC) (WMD: 0.64 cm, 95% CI: -3.18 to 4.48, p = 0.74). Also, tibolone treatment neither changed the systolic BP (WMD: 2.60 mmHg, 95% CI: -2.52 to 7.72, p = 0.31) nor the diastolic BP (WMD: 0.711 mmHg, 95% CI: -2.52 to 3.94, p = 0.66), but increased CRP levels by 0.44 mg/L (95% CI: 0.10 to 0.78, p = 0.01). Tibolone treatment administered in postmenopausal women increased BMI and CRP but did not change body weight, WC, and SBP. Diastolic BP decreased after the tibolone intervention only in the studies lasting 26 weeks versus ˃26 weeks.

The effect of tibolone treatment on fasting blood sugar, insulin, insulin resistance and endothelial function in postmenopausal women: A meta-analysis of randomized controlled trials

BACKGROUND AND AIM

The menopause is associated in females with the presence of dysglycemia, insulin resistance and with the development of endothelial dysfunction. Tibolone (TIB) is a synthetic steroid compound with selective oestrogenic and, to a lesser extent, progestogenic and androgenic properties prescribed to postmenopausal women to alleviate the symptoms of the climaterium and to prevent the development of osteoporosis. However, the impact of TIB on fasting blood sugar (FBS), insulin, Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) index and flow-mediated dilation (FMD) in women has not been evaluated so far. Thus, to investigate this research question, we conducted the present systematic review and meta-analysis.

METHODS

Two independent reviewers searched the Scopus, Web of Science, PubMed/Medline and Embase databases up to 20 December 2020. The weighted mean differences (WMDs) and the 95% confidence intervals (CI) were calculated using the DerSimonian and Laird random effects models between the TIB and control groups and included in the forest plot.

RESULTS

The overall findings were generated from 12 eligible randomized controlled trials. As compared to controls, TIB administration resulted in a significant reduction of FBS (WMD: -3.06 mg/dL, 95% CI: -5.30 to -0.82, P = 0.007), and of the HOMA-IR index (WMD: -0.61, 95% CI: -1.11 to -0.11, P = 0.01). However, treatment with TIB did not lead to significant changes of the FMD (WMD: 0.78%, 95% CI: -0.20 to 1.77, P = 0.12) or of insulin levels (WMD: -0.10 mIU/L, 95% CI: -2.04 to 1.83, P = 0.91).

CONCLUSION

TIB administration can decrease FBS and the HOMA-IR index in postmenopausal women. However, the use of TIB does not influence insulin levels or FMD.

The effect of tibolone treatment on lipid profile in women: A systematic review and dose-response meta-analysis of randomized controlled trials

Inconsistencies exist with regard to influence of tibolone treatment on the lipid profile. The reasons for these inconsistencies might derive from several factors, i.e., differences in baseline variables, intervention duration, participants' health status or baseline body mass index (BMI). To address these inconsistencies, based on a systematic search in Scopus, PubMed/Medline, Web of Science, and Embase for papers published until 21 December 2020, we conducted the current dose-response meta-analysis of randomized controlled trials (RCTs) to determine the impact of tibolone treatment on the lipid profile. The overall findings were derived from 26 RCTs. Tibolone administration decreased total cholesterol (TC) (weighted mean difference, WMD: -18.55 mg/dL, CI: -25.95 to -11.16, P < 0.001), high-density lipoprotein-cholesterol (HDL-C) (WMD: -9.42 mg/dL, CI: -11.83 to -7.01, P < 0.001) and triglyceride (TG) (WMD: -21.43 mg/dL, CI: -27.15 to -15.70, P < 0.001) levels. A significant reduction in LDL-C occurred when tibolone was prescribed for ≤ 26 weeks (WMD: -7.64 mg/dL, 95% CI: -14.58 to -0.70, P = 0.031) versus > 26 weeks (WMD: -8.84 mg/dL, 95% CI: -29.98, 12.29, P = 0.412). The decrease in TG (WMD: -22.64 mg/dL) and TC (-18.55 mg/dL) concentrations was more pronounced in patients with BMI ≥ 25 kg/m²versus BMI < 25 kg/m². This systematic review and meta-analysis discovered that tibolone decreases TC, HDL-C and TG levels. LDL-C concentrations are significantly reduced when tibolone administration lasts for ≤ 26 weeks.

Tibolone as Hormonal Therapy and Neuroprotective Agent

Tibolone (TIB), a selective tissue estrogenic activity regulator (STEAR) in clinical use by postmenopausal women, activates hormonal receptors in a tissue-specific manner. Estrogenic activity is present mostly in the brain, vagina, and bone, while the inactive forms predominate in the endometrium and breast. Conflicting literature on TIB's actions has been observed. While it has benefits for vasomotor symptoms, bone demineralization, and sexual health, a higher relative risk of hormone-sensitive cancer has been reported. In the brain, TIB can improve mood and cognition, neuroinflammation, and reactive gliosis. This review aims to discuss the systemic effects of TIB on peri- and post-menopausal women and its role in the brain. We suggest that TIB is a hormonal therapy with promising neuroprotective properties.

Effects of tibolone or continuous combined oestradiol and norethisterone acetate on lipids, high-density lipoprotein subfractions and apolipoproteins in postmenopausal women in a two-year, randomized, double-blind, placebo-controlled trial

OBJECTIVE

To compare the effects of (a) tibolone, (b) continuous combined oestrogen plus progestogen and (c) placebo on plasma lipid and lipoprotein markers of cardiovascular risk in healthy postmenopausal women.

STUDY DESIGN

Randomized, single-centre, placebo-controlled, double-blind study.

PATIENTS

One hundred and one postmenopausal women were randomized (1:1:1) into one of three groups taking daily 2.5 mg tibolone, continuous oral oestradiol-17β 2 mg plus norethisterone acetate 1 mg daily (E₂ /NETA) or placebo.

MAIN OUTCOME MEASURES

Fasting serum lipid, lipoprotein and apolipoprotein concentrations measured at baseline and after 6, 12 and 24 months of treatment.

RESULTS

Both tibolone and E₂ /NETA lowered plasma total cholesterol concentrations relative to placebo. With tibolone, high-density lipoprotein cholesterol (HDL-C) was reduced (-27% at 24 months, P < .001), the greatest effect being in the cholesterol-enriched HDL₂ subfraction (-40%, P < .001). Tibolone's effect on HDL concentrations was also apparent in the principal HDL protein component, apolipoprotein AI (-29% at 24 months, P < .001). However, there was no significant effect of tibolone on low-density or very low-density lipoprotein cholesterol (LDL-C and VLDL-C, respectively). By contrast, the greatest reduction in cholesterol with E₂ /NETA was in LDL-C (-22% at 24 months, P = .008). E₂ /NETA reduced HDL-C to a lesser extent than tibolone (-12% at 24 months, P < .001). Effects on HDL apolipoproteins were similarly diminished relative to tibolone. E₂ /NETA had no effect on VLDL-C or on the protein component of LDL, apolipoprotein B.

CONCLUSION

Tibolone reduces serum HDL. E₂ /NETA reduces LDL cholesterol but not apolipoprotein B, suggesting decreased cholesterol loading of LDL. Any impact these changes may have on CVD risk needs further investigation.

Cardiovascular Risk/Benefit Profile of MHT

Background and Objectives: Data emerging from the Women’s Health Initiative (WHI) study point toward an association between menopausal hormone therapy (MHT) and cardiovascular (CV) risk. However, post hoc subgroup analyses stratifying participants according to their age and time since menopause, have opened the way to a better understanding of the relationship between estrogen and CV risk. The aim of this review was to revise the current literature and evaluate the CV risk or benefit following administration of MHT considering several factors such as MHT timing, dose, route of administration, and formulation. Materials and Methods: An electronic databases search of MEDLINE (PubMed), Cochrane Central Register of Controlled Trials, Web of Science, SCOPUS, congress abstracts, and Grey literature (Google Scholar; British Library) was performed, with the date range from each database’s inception until June 2019. All the studies evaluating MHT and cardiovascular risk, including thromboembolism or stroke, were selected. Results: Timing of MHT initiation was shown to be a critical factor in CV risk assessment. In concordance with the “timing hypothesis”, healthy symptomatic women who initiated MHT when aged younger than 60 years, or who were within 10 years of menopause onset, have demonstrated a reduction in both coronary heart disease (CHD) risk and all-cause mortality. In particular, MHT therapy was associated with improvement of subclinical signs of atherosclerosis. Venous thromboembolism (VTE) risk is reduced when low doses of oral estrogen are used. Moreover, transdermal hormonal application significantly reduces CV risk compared with oral administration. MHT impact on the CV system is influenced by either factors inherent to the specific regimen, or factors inherent to the specific patient. Hence, individualization of care is necessary. Conclusion: CV risk calculation should be considered by clinicians in order to exclude patients with high CV risk, in whom MHT is contraindicated. Assessing risks and benefits in a patient-centered approach according to individual’s features, health status, and personal preferences is important in order to realize a safe and effective treatment.

Comparison of Ticagrelor Versus Prasugrel for Inflammation, Vascular Function, and Circulating Endothelial Progenitor Cells in Diabetic Patients With Non-ST-Segment Elevation Acute Coronary Syndrome Requiring Coronary Stenting: A Prospective, Randomized, Crossover Trial

OBJECTIVES

This study compared adenosine-associated pleiotropic effects of the 2 P2Y₁₂ receptor antagonists on vascular function, systemic inflammation, and circulating endothelial progenitor cells (EPCs).

BACKGROUND

Both ticagrelor and prasugrel have potent antiplatelet effects. However, only ticagrelor inhibits cellular uptake of adenosine.

METHODS

Using a randomized, crossover design with 10-week follow-up ticagrelor or prasugrel was administered to type 2 diabetic patients with non-ST-segment elevation acute coronary syndrome requiring stent implantation. A total of 62 patients underwent randomization in a 1:1 ratio to receive ticagrelor or prasugrel for 5 weeks followed by a direct cross over to the alternative treatment for 5 additional weeks. Brachial artery flow-mediated dilation, inflammatory markers, and number of circulating EPCs were compared.

RESULTS

Improvement in brachial artery flow-mediated dilation was greater in the ticagrelor group (0.15 ± 0.19 mm vs. -0.03 ± 0.18 mm; p < 0.001). Moreover, ticagrelor compared with prasugrel decreased interleukin 6 (-0.58 ± 0.43 pg/ml vs. -0.05 ± 0.24 pg/ml; p < 0.001), tumor necrosis factor alpha (-5.62 ± 4.40 pg/ml vs. -0.42 ± 2.64 pg/ml; p < 0.001), and increased adiponectin (2.31 ± 2.00 μg/ml vs. 0.08 ± 1.50 μg/ml; p < 0.001) during 10-week follow-up. Other inflammatory cytokines like high-sensitivity C-reactive protein and soluble vascular cell adhesion molecule-1 were decreased in both groups. Ticagrelor compared with prasugrel significantly increased absolute numbers of circulating EPCs CD34+/KDR+ (42.5 ± 37.8 per μl vs. -28.2 ± 23.7 per μl; p < 0.001), CD34+/CD117+ (51.9 ± 77.2 per μl vs. -66.3 ± 45.2 per μl; p < 0.001), and CD34+/CD133+ (55.2 ± 69.2 per μl vs. -28.0 ± 34.1 per μl; p < 0.001).

CONCLUSIONS

Compared with prasugrel, ticagrelor significantly decreased inflammatory cytokines such as interleukin 6 and tumor necrosis factor alpha and increased circulating EPCs, contributing to improved arterial endothelial function in diabetic non-ST-segment elevation acute coronary syndrome patients. Thus, data support that pleiotropic effects of ticagrelor beyond its potent antiplatelet effects could contribute to additional clinical benefits. (Comparison of Ticagrelor vs. Prasugrel on Inflammation, Arterial Stiffness, Endothelial Function, and Circulating Endothelial Progenitor Cells in Diabetic Patients With Non-ST Elevation Acute Coronary Syndrome [NSTE-ACS] Requiring Coronary Stenting; NCT02487732).

The cross-sectional association between vasomotor symptoms and hemostatic parameter levels in postmenopausal women

OBJECTIVE

Vasomotor symptoms (VMS) may be a marker of cardiovascular risk. We aimed to evaluate the cross-sectional association of VMS presence and severity with hemostatic parameter levels measured at baseline among Women's Health Initiative (WHI) Hormone Therapy trial postmenopausal participants.

METHODS

This cross-sectional analysis included 2,148 postmenopausal women with measures of VMS presence and severity reported in the 4 weeks before WHI baseline, who were not using warfarin or hormone therapy and for whom the following baseline hemostatic parameters were measured within the WHI Cardiovascular Disease Biomarker Case-Control Study: antithrombin, plasminogen activator inhibitor-1, protein C antigen, total and free protein S antigen, total and free tissue factor pathway inhibitor, D-dimer, normalized activated protein C sensitivity ratio, and thrombin generation. Using multiple linear regression, we estimated the adjusted average difference in each hemostatic parameter associated with VMS presence and severity. A multiple comparisons-corrected P value was computed using the P-min procedure to determine statistical significance of our smallest observed P value.

RESULTS

Women were 67 years of age on average and 33% reported VMS presence at baseline. There was some suggestion that VMS presence may be associated with a -0.34 adjusted difference in normalized activated protein C sensitivity ratio compared with no VMS (95% CI, -0.60 to -0.087; P = 0.009), but this association was not significant after correction for multiple comparisons (P = 0.073). VMS presence or severity was not significantly associated with the other hemostatic parameters.

CONCLUSIONS

We found no convincing evidence that VMS presence or severity was associated with levels of hemostatic parameters among postmenopausal women.

The effects of different hormone treatment on endothelial function in healthy postmenopausal women

We aimed to compare the effects of different types of hormone treatment (HT) on endothelial function by means of brachial artery ultrasonographic examination in postmenopausal women. Sixty-two healthy postmenopausal women were included in this study. Subjects were assigned to one of the five groups receiving 6 months of treatment [estrogen (conjugated estrogen), estrogen (conjugated estrogen) plus progesterone (medroxyprogesterone acetate; MPA), raloxifene, tibolone or control]. Endothelial function was assessed by measurement of flow-mediated dilatation (FMD) and nitrate-dependent dilatation in the brachial artery. At the end of 6 months, FMD values were found to be significantly increased in women with HT use than the control group (p = 0.001). In subgroups, FMD increased significantly in the estrogen [12 ± 7 versus 25 ± 8, p = 0.001] and raloxifene groups [7 ± 5 versus 11 ± 3, p < 0.01] compared to tibolone and estrogen plus progesterone groups. In conclusion, endothelial function is impaired in postmenopausal women. Both estrogen and raloxifene regimens may improve endothelial functions in healthy postmenopausal women. The direct protective effects of these HT on the healthy endothelium may be more remarkable than the favorable effects on lipid profile.

Primary Prevention of Cardiovascular Disease with HRT

Prevention of cardiovascular disease has increasingly important health implications as our population ages. Menopause is associated with the development of cardiovascular risk factors and there are many plausible biological mechanisms through which estrogen may confer cardiovascular protection. Despite a wealth of observational data to support the use of estrogen, large randomized controlled trials failed to demonstrate a benefit. It is now becoming clearer that the beneficial cardiovascular effects of estrogen are greatest in younger women and those closest to menopause. This has led to the development of the timing hypothesis. Use of age-appropriate estrogen doses is crucial to maximize cardiovascular benefits while minimizing risk of adverse effects such as venous thromboembolism and stroke.

Effects of menopause and tibolone on different cardiovascular biomarkers in healthy women

BACKGROUND AND AIM

The effects of tibolone on cardiovascular risk is not yet fully understood today. We designed this study to assess the effect of the menopausal status and tibolone treatment (2.5 mg/day for 3 months) on different biomarkers of cardiovascular risk in healthy women.

METHODS

Blood arterial pressure were measured, and blood samples collected for glucose, lipid profile (total cholesterol, high density lipoproteins, HDL, low density lipoproteins, and triglycerides), inflammatory (C-reactive protein, Interleukin-6, IL-6, tumor necrosis factor alpha, TNF alpha) and oxidative stress (hydroperoxides and antioxidant capacity) evaluation in 15 premenopausal (mean age: 30 +/- 4 years) and 15 postmenopausal (mean age: 52 +/- 3, mean time from menopause 1.4 +/- 0.4 years) women before and after tibolone treatment.

RESULTS

The menopausal status is associated with increased systolic and diastolic pressure (p<0.05), higher IL-6 (p<0.05) and TNF alpha (p<0.01), and lower antioxidants (p<0.01). However, blood pressure (p<0.05), glucose (p<0.05), TNF alpha (p<0.05) and HDL (p<0.05) fell after tibolone, which did not significantly affect levels of the other biochemical parameters.

CONCLUSIONS

As menopause is associated with increased blood pressure, inflammation and oxidative stress, tibolone restores blood pressure and has beneficial effect on inflammation and glycemia without worsening oxidative stress, although it also reduces HDL levels. Such modifications should be taken into account when tailoring menopausal therapies to specific requirements of each woman.

Tibolone in postmenopausal women: a review based on recent randomised controlled clinical trials

AIM

To critically discuss the use of tibolone (T), in light of a series of very recent double-blind placebo (PL) controlled trials (LISA, LIFT, OPAL, THEBES, LIBERATE) conducted worldwide in a large number of postmenopausal women (PMW).

METHODS

The most relevant publications on T therapy in PMW were considered with emphasis on menopausal symptoms, quality of life, sexuality, bone, cardiovascular system (CVS) and oncologic risk.

RESULTS

T significantly relieves climacteric symptoms and improves mood and sexual well-being (LISA). T is as effective as estrogen-progestin therapy in preventing bone loss and reducing the relative risk of vertebral and non-vertebral fractures (LIFT). By using surrogate endpoints of the individual risks for the CVS, studies show mixed results, but a favourable effect on acute miocardial infarction and thromboembolism has been documented (THEBES, LIFT, OPAL). Although findings about endometrial and colon cancer are reassuring, conclusive data on breast cancer risk with T are not available and an increased risk of recurrence in women with previous breast cancer emerged (LIBERATE).

CONCLUSIONS

T is effective in treating menopausal syndrome with a good tolerability profile. In spite of some unsolved issues in term of safety, T is still a good treatment option for early PMW.

Updated clinical recommendations for the use of tibolone in Asian women

Tibolone, which is indicated for the relief of climacteric symptoms and the prevention of osteoporosis in postmenopausal women, has a tissue-specific mode of action different to that of conventional hormone replacement therapy (HRT). A large proportion of Asian postmenopausal women experience symptoms that most frequently include musculoskeletal pain, insomnia, forgetfulness, hot flushes and sexual dysfunction, and there is a need to address their specific requirements. Recent studies show that, in comparison to HRT, tibolone is as effective in alleviating menopausal symptoms and preventing bone loss, has a greater positive effect on sexual dysfunction and is associated with less vaginal bleeding, but it is rarely mentioned in guidelines for menopausal treatment. Levels of awareness amongst women about treatments for menopausal symptoms vary between Asian countries but, even in countries where awareness is high, HRT usage is much lower than in the West. To provide a practical approach to the use of tibolone in Asian postmenopausal women, a panel of experts in the management of menopause from 11 Asia Pacific countries has developed recommendations for its use, based on the evidence from clinical studies published since 2005. However, as much of the clinical data reviewed are from international studies, the recommendations and the treatment algorithm presented here are widely applicable.

Effect of two oral doses of 17beta-estradiol associated with dydrogesterone on thrombin generation in healthy menopausal women: a randomized double-blind placebo-controlled study

Oral hormone therapy is associated with an increased risk of venous thrombosis. Drug agencies recommend the use of the lowest efficient dose to treat menopausal symptoms for a better risk/ratio profile, although this profile has not been totally investigated yet. The aim of the study was to compare the effect of the standard dose of 17beta-estradiol to a lower one on thrombin generation (TG). In a 2-month study, healthy menopausal women were randomized to receive daily 1mg or 2 mg of 17beta-estradiol (E1, n = 24 and E2, n = 26; respectively) with 10 mg dydrogesterone or placebo (PL, n = 22). Plasma levels factors VII, X, VIII and II were assessed before and after treatment as well as Tissue factor triggered TG, which allows the investigation of the different phases of coagulation process. The peak of thrombin was higher in hormone therapy groups (E1: 42.39 +/- 50.23 nm, E2: 31.08 +/- 85.86 nm vs. 10.52 +/- 40.63 nm in PL, P = 0.002 and P = 0.01). Time to reach the peak was also shortened (PL: 0.26 +/- 0.69 min vs. E1: -0.26 +/- 0.80 min, E2: -0.55 +/- 0.79 min, P <10(-3) for both comparisons) and mean rate index of the propagation phase of TG was significantly increased. Among the studied clotting factors, only the levels of FVII were significantly increased after treatment administration. The two doses of 17beta-estradiol induced in a similar degree an acceleration of the initiation and propagation phase of tissue factor triggered thrombin generation and a significant increase of FVII coagulant activity.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Tibolone in postmenopausal women with systemic lupus erythematosus: a pilot study

OBJECTIVE

To determine the influence of the use of tibolone on the frequency of flares of systemic lupus erythematosus (SLE) in postmenopausal patients.

METHODS

Thirty patients with inactive or controlled SLE were included in the study. Patients were randomized to receive a 12-month course of either tibolona (2.5 mg/day) or placebo. The following were investigated: hypoestrogenism symptoms by Kupperman index, weight; anti-dsDNA antibodies; SLE flares (frequency) assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI); and biochemical profile (total cholesterol, high-density lipoprotein cholesterol [HDL-C], triglycerides, complement components [C3/C4], alpha1-acid glycoprotein, urea, creatinine, 24-h proteinuria, C-reactive protein and erythrocyte sedimentation rate).

RESULTS

The reduction in Kupperman index was greater in the patients using tibolone than in those using placebo. The mean SLEDAI was not different between the groups during the study as well as SLE flare frequency (tibolone: 2/15 [13.3%] vs. placebo: 1/15 [6.7%]; p=0.54). All cases of flares were considered mild to moderate. Although the groups were similar at the baseline evaluation, after 6 and 12 months of treatment lower values were found in the tibolone group for triglycerides (6 months: 161.6+/-30.9 mg/dl vs. 194.4+/-46.5; p=0.04; 12 months 163.7+/-29.8 mg/dl vs. 204.1+/-49.9 mg/dl; p=0.02; tibolone vs. placebo group, respectively) and for HDL-C (6 months: 40.7+/-10.7 mg/dl vs. 53.4+/-16.5; p=0.02; 12 months: 47.2+/-7.9 mg/dl vs. 63.2+/-16.3mg/dl; p<0.01; tibolone vs. placebo group, respectively). There were no differences between the two groups in any of the remaining variables.

CONCLUSION

In patients with inactive or stable SLE, the short-term use of tibolone did not significantly affect the frequency of flares. In addition, tibolone was well tolerated and effective to control hypoestrogenism related symptoms in SLE patients.

Low PAI-1 activity in relation to inflammatory parameters, insulin profile and body mass index

BACKGROUND AND OBJECTIVE

High plasminogen activator inhibitor type 1 (PAI-1) activity is associated with inflammatory reactions and insulin resistance, but it is unclear what regulates PAI-1 activity at the low end. The purpose of this study was to investigate if patients with low PAI-1 activity have a lack of inflammatory response or a low insulin level.

DESIGN

Retrospective cohort study with internal controls.

SUBJECTS

Sixty-three patients referred for investigation of bleeding tendency and with low PAI-1 activity were compared with 118 patients with normal or high PAI-1 activity.

OUTCOME

Levels of C-peptide, proinsulin, high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6). Adjustments were made for body mass index (BMI), oral oestrogens and age. Low PAI-1 activity was defined as less than 1 U mL(-1).

RESULTS

Body mass index in the low normal range, oral oestrogens, young age and low C-peptide were significantly associated with low PAI-1 activity and there was a trend for association with IL-6 in univariable analysis. The effect of age disappeared after correction for oral oestrogens and the effect of C-peptide and IL-6 disappeared after further adjustments. Low BMI remained as the strongest predictor of low PAI-1 activity.

CONCLUSION

Patients with bleeding tendency and low PAI-1 activity have inflammatory and insulin profiles similar to those with normal or high PAI-1, whereas BMI seems to be the most important determinant.

Differential impact of conventional-dose and low-dose postmenopausal hormone therapy, tibolone and raloxifene on C-reactive protein and other inflammatory markers

BACKGROUND

Postmenopausal hormone therapy (HT) is associated with an increased risk for arterial and venous thrombosis.

OBJECTIVES

To compare the impact of HT, tibolone, and raloxifene on C-reactive protein (CRP) and other inflammatory markers, and to investigate possible underlying mechanisms for changes in CRP and D-dimer.

METHODS

Two hundred and two healthy women were randomly assigned to treatment for 12 weeks with either low-dose HT containing 1 mg of 17beta-estradiol and 0.5 mg of norethisterone acetate (NETA) (n = 50), conventional-dose HT containing 2 mg of 17beta-estradiol and 1 mg of NETA (n = 50), 2.5 mg of tibolone (n = 51), or 60 mg of raloxifene (n = 51).

RESULTS

CRP increased in the conventional-dose HT and low-dose HT groups. These changes were significantly more pronounced in the conventional-dose HT group (RMANOVA, P = 0.02). Also, tibolone was associated with an increase in CRP, in contrast to raloxifene, which reduced CRP. Reductions in levels of Lp(a), intercellular adhesion molecule-1 (ICAM-1), P-selectin, E-selectin, monocyte chemotactic protein 1 (MCP-1) and interleukin-6 (IL-6) were observed in all treatment groups. The changes were most pronounced for the conventional-dose HT group, and least pronounced for the raloxifene group, whereas the changes in those allocated to tibolone and low-dose HT were intermediary. Increased levels of tumor necrosis factor (TNF)-alpha and von Willebrand factor (VWF) were seen in the raloxifene group. We observed positive associations between changes in IL-6, VWF, MCP-1, and CRP.

CONCLUSIONS

The regimens had markedly different impacts on markers of inflammation. The average increase in CRP was not accompanied by increases in the average levels of IL-6, TNF-alpha or other markers, but women with large reductions in IL-6 had reduced increases in CRP.

Cardiovascular Effects of Tibolone: A Selective Tissue Estrogenic Activity Regulator

Traditionally, it was accepted that long-term hormone replacement therapy (HRT) has a cardiovascular beneficial effect in postmenopausal women with and without coronary artery disease (CAD). However, randomized trials in postmenopausal women have not shown any benefit in either primary or secondary prevention of cardiovascular events. Therefore, these findings have raised the question of whether traditional HRT (i.e., estrogen and progesterone) has a cardioprotective effect in women at risk for or with established CAD. Concerns about the use of conventional HRT have led to a search for alternatives. Tibolone is a synthetic compound with estrogenic, androgenic, and progestogenic properties that relieves climacteric symptoms and prevents postmenopausal bone loss. Tibolone possesses a tissue-selective mechanism of action that differs from that of estrogen and/or progestogen. Unlike these compounds, tibolone's metabolites play a central role in its mode of action. Tibolone is widely used for HRT. However, its clinical impact on cardiovascular disease is still under study. The current review focuses on the effects of tibolone on the cardiovascular system and discusses clinical investigations with this compound in postmenopausal women.

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.

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.

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.

Combined therapy with ramipril and simvastatin has beneficial additive effects on tissue factor activity and prothrombin fragment 1+2 in patients with type 2 diabetes

Tissue factor (TF) plays a pivotal role in thrombus formation. Statins and angiotensin converting enzyme inhibitors attenuate expression of TF by distinct mechanism. Therefore, we hypothesized that combined therapy with simvastatin and ramipril may have additive beneficial anti-atherogenic effects to lower TF activity when compared with either drug alone. This was a randomized, double-blind, placebo-controlled cross-over trial with three treatment arms (each 2 months) and two washout periods (each 2 months). Fifty patients with type 2 diabetes were given simvastatin 20 mg and placebo, simvastatin 20 mg and ramipril 10 mg, or ramipril 10 mg and placebo daily during each treatment period. Simvastatin and ramipril monotherapy tended to reduce TF activity (0.53 to 0.46 nM, P=0.056; 0.54 to 0.50 nM, P=0.167, respectively) while combined therapy had a significant effect (0.64 to 0.43 nM, P<0.001). All three therapies significantly reduced prothrombin fragment 1+2 (F1+2) levels from their respective baselines (P=0.037, P<0.001, and P=0.057, respectively). Combined therapy significantly reduced TF activity and F1+2 levels to a greater extent than either simvastatin or ramipril alone (P=0.029 and P=0.040 by ANOVA, respectively). Percent changes in TF activity and percent changes in F1+2 levels were significantly correlated. All three therapies reduced CD40 ligand levels from their respective baselines (P=0.098, P<0.001, and P=0.002, respectively) with no significant differences among these three therapies (P=0.204 by ANOVA). Ramipril combined with simvastatin significantly reduces plasma TF activity and F1+2 levels to a greater extent than monotherapy with either drug in patients with type 2 diabetes.

Tibolone and estradiol plus norethisterone acetate similarly influence endothelium-dependent vasodilatation in healthy postmenopausal women

In healthy postmenopausal women, E(2) plus norethisterone acetate (1 mg + 0.5 mg) or tibolone (2.5 mg) similarly modify flow-mediated endothelium-dependent vasodilatation. The effect is dependent on baseline vasodilator reserve, with low values being augmented by either treatment.

Cross-sectional association between markers of inflammation and serum sex steroid levels in the postmenopausal estrogen/progestin interventions trial

BACKGROUND

Standard risk factors do not adequately capture cardiovascular risk in postmenopausal women. We sought to determine the associations between levels of sex steroids and levels of inflammatory markers in postmenopausal women.

METHODS

We analyzed baseline data from a subset of postmenopausal women aged 45-64 years who had stored samples during a randomized controlled trial. We measured levels of C-reactive protein (CRP), interleukin-6 (IL-6), matrix metalloproteinase-9 (MMP-9), soluble intercellular adhesion molecule (sICAM), and circulating sex steroids. Multiple linear regression models were created with each of the following hormone levels as the primary exposure variable: estrone, total estradiol, bioavailable estradiol, total testosterone, bioavailable testosterone, progesterone, and sex hormone-binding globulin (SHBG). Sociodemographic and lifestyle covariates were derived from standardized self-report questionnaires and direct measurement (weight, height).

RESULTS

Mean age of the 623 women was 56 years. After adjustment for age, body mass index (BMI), physical activity, alcohol consumption, and smoking, the bioavailable testosterone level (p = 0.03) was positively and the SHBG level (p < 0.001) was negatively associated with the logCRP level. The increment in CRP level between the highest and lowest quartile of bioavailable testosterone was 1.28 microg/mL. The increment in CRP level between the lowest and highest quartile of SHBG was 2.62 microg/mL. Compared with SHBG or bioavailable testosterone as predictors of logCRP in separate regression models, when both SHBG and bioavailable testosterone were included in the same multivariate linear regression model, only SHBG remained a statistically significant predictor of logCRP. Progesterone level was positively associated with the logMMP-9 level (p < 0.001); no other sex steroid level was associated with the logMMP-9 level. In multiply adjusted models, no association was found between levels of any sex steroid and IL-6 or sICAM level.

Biochemical markers surrogating on vascular effects of sex steroid hormones

The main mechanism of possible cardioprotection by estrogens appears to be a direct effect on the vasculature, resulting in an improvement of endothelial function and inhibition of atherogenesis. Numerous observational and experimental studies have demonstrated a positive correlation between estrogens and various biochemical markers surrogating direct vascular effects. In general, most markers are influenced in a similar way by oral and transdermal hormone therapy, although oral therapy may have a faster and more pronounced effect. The main difference between oral and transdermal administration may be confined to markers that are mainly or exclusively produced in the liver. Clinical studies demonstrate that progestogen addition can have an impact on the beneficial estrogen-induced changes of biochemical markers. Concerning the effects of tibolone, inconsistent data have been found. Overall, tibolone-induced beneficial changes on the various biochemical markers appear to be less marked compared with those of hormone therapy. The few data available on the direct effects of androgens on the vascular wall indicate a less favorable action of androgens on biochemical markers than of estrogens. The practical relevance of marker measurements is currently under discussion. Although evidence strongly supports some of these markers as predictors of acute events, it remains to be established whether modifying circulating levels of these markers will influence outcomes.

Tibolone Improves Myocardial Perfusion in Postmenopausal Women With Ischemic Heart Disease

OBJECTIVES

We sought to determine the effect of tibolone on myocardial perfusion in postmenopausal women with ischemic heart disease.

BACKGROUND

Tibolone is a steroid that relieves climacteric symptoms and prevents osteoporosis. Recent studies have suggested a cardioprotective effect of this compound. However, its role on myocardial perfusion remains uncertain.

METHODS

Single-photon emission computed tomography myocardial perfusion imaging was performed in 26 postmenopausal women. Patients were randomly assigned to tibolone for six months (treatment group) or to usual care (control group). All women underwent cardiac imaging at baseline and at six months.

RESULTS

Mean stress perfusion defect (summed stress score) was moderate and did not differ between the two groups (8 +/- 3 vs. 9 +/- 4; p = NS). Summed difference score also was similar for both groups (7 +/- 3 vs. 8 +/- 3; p = NS). The six-month study revealed that summed stress and summed difference scores significantly improved in the treatment group (to 3 +/- 3 and to 2 +/- 2; p < 0.001) whereas it remained unchanged for control patients (to 10 +/- 4 and to 8 +/- 2; p = NS).

CONCLUSIONS

In postmenopausal women with ischemic heart disease, six months of therapy with tibolone significantly improved stress myocardial perfusion and the "amount of ischemia."

Sex dimorphism in cardiac pathophysiology: experimental findings, hormonal mechanisms, and molecular mechanisms

The higher cardiovascular risk in men and post-menopausal women implies a protective action of estrogen. A large number of experimental studies have provided strong support to this concept. However, the recent clinical trials with negative outcomes regarding hormone replacement therapy call for "post hoc" reassessment of existing information, models, and research strategies as well as a summary of recent findings. Sex steroid hormones, in particular estrogen, regulate numerous processes that are related to the development and progression of cardiovascular disease through a variety of signaling pathways. Use of genetically modified models has resulted in interesting information on diverse actions mediated by steroid receptors. By focusing on experimental findings, we have reviewed hormonal, cellular, and signaling mechanisms responsible for sex dimorphism and actions of hormone replacement therapy and addressed current limitations and future directions of experimental research.

Effects of tibolone on the risk factors for cardiovascular diseases in postmenopausal women

Background/Aim. Tibolone is a preparation that belongs to the group of steroidal substances. The effects of the use of the use of tibolone are the consequence of the activities of its metabolities, considering that their hormonal activity depends on the type of tissue in which they develop. The aim of this study was to evaluate the influence of the use of tibolone on risk factors for the development of cardiovascular diseases in postmenopausal women. Methods. A prospective observational stady included 94 patients who had the concentration of l7? estradiol < 50 pg/ml, and who was in menopause more than a year. Out of the total number of patients, 63 accepted to receive tibolone 2.5 mg daily (tibolone group), while 31 of the patients refused to take tibolone (control group). We measured the concentration of lipids (cholesterol, LDL cholesterol, HDL cholesterol, triglicerides), antitrombin III, fibrinogen, and C-reactive protein, before and after the treatment within a 6-month period. Then, we compared the difference between the values of concentrations and tested the statistical significance of the difference. We also evaluated the changes of values in the concentrations of the examinated parameters inside a 6-month period in the control group. Results. In 31 patients of the control group, from the control group there were no significant changes in the values of the defined parameters as compared to their initial values after six months. But there were changes of statistical significance (p < 0.001) in values of the concentrations of the exeminated parameters before and after the treatment in the tibolone group. In fact, we recorded decreases in the total cholesterol by 17.8%, HDL cholesterol by 27%, LDL cholesterol by 4% (without statistical significance p > 0.05) and triglicerids by 35%. There were no statistical differences in the concentrations of antitrombin III, fibrionogen, and C-reactive proteine in the tibolone group before and after the treatment. Conclusion. The use of tibolone dose decrease the concentration of the total cholesterol, triglicerides, HDL cholesterol, without a significant decrease of LDL cholesterol. Also, the use of tibolone does not have any significant effect on the concentrations of antitrombin III, fibrinogen and C-reactive proteine. The number of serum parameters measured in this study was limited, thus that was the reason to discuss only about the metabolism of lipids in the patients from the tibolone group. The final conclusion about the risk for cardiovascular diseases in the patients on tibolone, howerer, reqnires were extensive further clinical exeminations.

Effects of Transdermal Estrogen Replacement Therapy on Cardiovascular Risk Factors

The prevalence of hypertension and cardiovascular disease increases dramatically after menopause in women, implicating estrogen as having a protective role in the cardiovascular system. However, recent large clinical trials have failed to show cardiovascular benefit, and have even demonstrated possible harmful effects, of opposed and unopposed estrogen in postmenopausal women. While these findings have led to a revision of guidelines such that they discourage the use of estrogen for primary or secondary prevention of heart disease in postmenopausal women, many investigators have attributed the negative results in clinical trials to several flaws in study design, including the older age of study participants and the initiation of estrogen late after menopause.Because almost all clinical trials use oral estrogen as the primary form of hormone supplementation, another question that has arisen is the importance of the route of estrogen administration with regards to the cardiovascular outcomes. During oral estrogen administration, the concentration of estradiol in the liver sinusoids is four to five times higher than that in the systemic circulation. This supraphysiologic concentration of estrogen in the liver can modulate the expression of many hepatic-derived proteins, which are not observed in premenopausal women. In contrast, transdermal estrogen delivers the hormone directly into the systemic circulation and, thus, avoids the first-pass hepatic effect.Although oral estrogen exerts a more favorable influence than transdermal estrogen on traditional cardiovascular risk factors such as high- and low-density lipoprotein-cholesterol levels, recent studies have indicated that oral estrogen adversely influences many emerging risk factors in ways that are not seen with transdermal estrogen. Oral estrogen significantly increases levels of acute-phase proteins such as C-reactive protein and serum amyloid A; procoagulant factors such as prothrombin fragments 1+2; and several key enzymes involved in plaque disruption, while transdermal estrogen does not have these adverse effects.Whether the advantages of transdermal estrogen with regards to these risk factors will translate into improved clinical outcomes remains to be determined. Two ongoing clinical trials, KEEPS (Kronos Early Estrogen Prevention Study) and ELITE (Early versus Late Intervention Trial with Estradiol) are likely to provide invaluable information regarding the role of oral versus transdermal estrogen in younger postmenopausal women.

Interleukin-6 and flow-mediated dilatation as markers of increased vascular inflammation in women receiving hormone therapy

OBJECTIVE

The lack of a beneficial long-term cardiovascular effect of hormone therapy and the early incidence of cardiovascular adverse events observed in recent randomized studies have been related to a heightened inflammatory effect of hormone therapy.

DESIGN

We evaluated the effect of different postmenopause therapies on inflammatory markers and endothelial function in 205 postmenopausal women before and after therapy.

RESULTS

all postmenopausal women, estrogens alone increased plasma levels of C-reactive protein (CRP) but decreased all other markers of inflammation including interleukin-6 (IL-6) (CRP: +75% +/- 11%, intracellular adhesion molecule: -21% +/- 4%, vascular cell adhesion molecule: -15% +/- 6%, E-selectin: -18% +/- 4%, s-thrombomodulin -10.5% +/- 3.7%, IL-6 -14% +/- 6%; percent changes, P < 0.01 compared with baseline). Raloxifene and tibolone did not significantly affect the overall inflammatory milieu. In a minority of patients, estrogen-progestogen associations and tibolone increased IL-6 levels and induced unfavorable changes on inflammation markers (CRP: +93% +/- 8%, intracellular adhesion molecule: -3% +/- 2%, vascular cell adhesion molecule: -5% +/- 2%, E-selectin: +6% +/- 2%, s-thrombomodulin: +5% +/- 2%, IL-6: +12% +/- 4%; percent changes compared with baseline). Patients with increased IL-6 levels were older and had a longer time since menopause. In all patients except those with increased IL-6 levels, hormone therapy improved endothelial function, whereas tibolone and raloxifene did not significantly change endothelial function compared with baseline. A worsening of endothelial function was detected in patients with increased IL-6 levels during therapy.

CONCLUSIONS

Postmenopausal hormone therapy is associated with decreased vascular inflammation; however, in patients with a longer time since menopause, postmenopause hormone therapy may increase inflammation and worsen endothelial function. These unfavorable vascular effects may be detected by an elevation in IL-6 levels and by a lack of improvement in endothelial function.

Significant differential effects of lower doses of hormone therapy or tibolone on markers of cardiovascular disease in post-menopausal women: a randomized, double-blind, crossover study

AIMS

We have previously reported that lower doses of hormone therapy (L-HT) and tibolone have different effects on markers of cardiovascular disease when compared with conventional doses of HT. The objective was to compare the effects of L-HT and tibolone on lipid profile, vasodilation, and factors associated with inflammation and haemostasis.

METHODS AND RESULTS

Forty-one women received a combination of micronized progesterone 100 mg with conjugated equine estrogen 0.3 mg vs. tibolone 2.5 mg alone daily in random order during 2 months with 2 months washout period. When compared with L-HT, tibolone significantly reduced total cholesterol (P<0.001), triglyceride (P<0.001), HDL cholesterol (P<0.001) levels, and triglyceride/HDL cholesterol ratios (P=0.004) except total cholesterol/HDL cholesterol ratios. Tibolone improved flow-mediated response to hyperaemia from baseline values (P<0.001) by a similar magnitude to L-HT. L-HT and tibolone did not increase high-sensitivity C-reactive protein relative to baseline values. L-HT reduced antithrombin III from baseline values (P=0.037), compared with tibolone showing no changes. However, there was no difference between either. In contrast, tibolone increased pro-thrombin fragment 1+2 (F1+2) from baseline values (P=0.002), compared with L-HT showing no changes. Tibolone significantly reduced plasma plasminogen activator inhibitor type 1 (PAI-1) antigen levels from baseline values (P=0.004), compared with L-HT showing no changes. The effects of L-HT and tibolone on F1+2 and PAI-1 were significantly different (P=0.045 and P=0.008, respectively).

CONCLUSION

Both tibolone and L-HT improved flow-mediated response by a similar magnitude and did not significantly increase high-sensitivity C-reactive protein. However, tibolone significantly reduced PAI-1, but increased F1+2 more than L-HT.

Does the type of hormone replacement therapy affect lipoprotein (a), homocysteine, and C-reactive protein levels in postmenopausal women?

BACKGROUND

The results of studies evaluating the effect of hormone replacement therapy (HRT) on the cardiovascular risk raise many controversies. This may be related to both the type of treatment used and the disregard of additional risk factors.

OBJECTIVE

The objective of the study was to evaluate the effect of natural estrogens taken transdermally and synthetic estrogens taken orally on the concentrations of lipoprotein (a) [Lp(a)], homocysteine, and C-reactive protein (CRP) in healthy women in the early postmenopausal period. Material The study was conducted on 61 healthy women with average age of 52.3 +/- 4.1 years, in the postmenopausal period, who were randomly assigned to 3 groups depending on the type and route of administration of the products. Group I (n = 24) was administered transdermal estrogens (micronized 17beta-estradiol; Systen, Janssen-Cilag, Switzerland) and progesterone in the second phase of the cycle. Group II (n = 21) was administered oral hormones (Cyclo-Menorette). Group III (n = 16), serving as a control, included women taking placebo in the form of patches. In each group, therapeutic cycles took 22 days and were followed by a treatment-free interval of 7 to 10 days for a 3-month period.

RESULTS

After 3 months of treatment, Lp(a) and homocysteine levels were not significantly different from the baseline, irrespective of the route of administration of estrogens or placebo. Both forms of HRT used indicate significant difference in changes of CRP concentration during 3 months of administration (analysis of variance P = .0356). CRP concentration values increased in the group of women using oral HRT from 1.22 to 2.68 mg/L. In the group of women using oral therapy, significantly more cases (61%) of increase in CRP concentration compared with 39% in the transdermal HRT group (chi(2) P = .015) were observed.

CONCLUSIONS

On the basis of our observations, it appears that in women in the early postmenopausal stage with normal initial concentrations of Lp(a) and homocystein, the form of therapy used has no influence on values of these parameters. The 2 forms of HRT therapy differ in effect, which is expressed as a change in CRP concentration. A tendency to increase CRP values when using oral HRT is observed, while such an effect is not observed in case of transdermal therapy after 3 months.

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

Hormone replacement therapy (HRT) was increasingly promoted over the last 40 years to improve quality of life, and to reduce the risks of osteoporotic fractures and coronary heart disease (CHD). In recent years, observational studies, randomized trials and systematic reviews of such trials have shown that HRT does not reduce, but actually increases cardiovascular risk. HRT increases the relative risks of venous thromboembolism (twofold), and of fatal or disabling stroke (by 50%); whilst increasing the early risk of myocardial infarction and having no protective effect against CHD on longer term use. Possible mechanisms for these increased cardiovascular risks include down-regulation of several inhibitory pathways of blood coagulation, resulting in increased coagulation activation, which promotes venous and arterial thrombosis. The implications for prescription are discussed, as are lessons for future evaluation of health care interventions.

Tibolone activates nitric oxide synthesis in human endothelial cells

After the unexpected findings of the Women's Health Initiative trial, indicating that traditional cardiovascular risk markers fail to predict the effects of hormone replacement therapy, it is of interest to characterize how steroids act on vascular cells. This is particularly important for tissue-specific drugs such as tibolone, whose actions may differ from other preparations. Because nitric oxide (NO) is a key regulator of vascular tone and atherogenesis, we studied its regulation by tibolone and its metabolites on human endothelial cells. Tibolone and its estrogenic metabolites (3alpha- and 3beta-OH tibolone) activate NO synthesis by recruiting functional estrogen receptors, whereas the progestogenic/androgenic metabolite (Delta(4) isomer) has no effect. During prolonged exposures, tibolone and the estrogenic compounds enhance the expression of endothelial NO synthase (eNOS). In addition, tibolone is able to induce rapid activation of eNOS, leading to rapid increases in the release of NO. Relevant for its clinical effects, the sulfated metabolites of tibolone are also effective in activating eNOS. Different from estrogen, rapid activation of eNOS does not rely on recruitment of phosphatidylinositol-3 kinase but rather on MAPK-dependent cascades. These results help to understand the mechanisms of action of tibolone on the cardiovascular system and have relevant clinical implications.

Estrogens, lipoproteins, and cardiovascular risk factors: an update following the randomized placebo-controlled trials of hormone-replacement therapy

PURPOSE OF REVIEW

The effects of hormone-replacement therapy on cardiovascular risk factors are examined. In an attempt to explain the results of recent randomized controlled trials in which no benefit of hormone-replacement therapy for postmenopausal women has been observed,

RECENT FINDINGS

Changes in lipoproteins in response to hormone-replacement therapy have now been analysed for both primary and secondary prevention studies. In none of the large randomized controlled trials was there any effect of hormone-induced changes in low-density lipoprotein, high-density lipoprotein, or triglyceride on clinical outcome. Further detailed studies of lipoprotein metabolism have not revealed any adverse effect of hormone-replacement therapy. Recent analysis of the Heart Estrogen/Progestin-Replacement Study data suggests hormone-replacement therapy reduces the risk of developing diabetes. The effect of hormone-replacement therapy on inflammatory markers and on flow-mediated dilatation is largely beneficial, although the effect on flow-mediated dilatation is modulated according to endothelial function, which is adversely affected by known risk factors, including age and presence of atherosclerosis. In this respect the work on polymorphisms of estrogen receptor-alpha may in due course help to define those women who would benefit most from use of estrogen. Crucially, oral but not transdermal hormone-replacement therapy increases activated protein C resistance independently of the presence of factor V Leiden. This effect increases the risk of venous thromboembolic events, which is reflected in the results of a hospital case control study of thromboembolism.

SUMMARY

Despite the outcome of the hormone-replacement therapy trials, recent work has confirmed the putative antiatherogenic effects of hormone-replacement therapy on lipoprotein metabolism. Metabolic differences of route of administration of estrogen, particularly on haemostatic variables, may explain this clinical paradox, which continues to be an important research area.

The influence of 5-year therapy with tibolone on the lipid profile in postmenopausal women with mild hypercholesterolemia

Our objective was to investigate the effects of 5-year therapy with tibolone on the lipid profile in postmenopausal women with mild hypercholesterolemia (total cholesterol, 241 +/- 7 mg/dl; LDL cholesterol, 153 +/- 9 mg/dl). Eighty-two patients were divided into two groups. Group A (53 women) received 2.5 mg of tibolone per day. Group B (29 women) received no tibolone. Total, low- and high-density lipoprotein cholesterol and lipoprotein(a) were found to be decreased in the tibolone group, by 17.7%, 32%, 15.5% and 12%, respectively (p < 0.01) throughout the 5-year treatment, while triglycerides showed no significant change. The lipid profile in the control group remained at its initial values. Menopausal symptoms disappeared in the treatment group within the first 5 months, whereas they deteriorated in the control group during the first 2 years. Although a few unwanted side-effects on hormone-dependent tissues were observed (including vaginal spotting in 11.3% and febrile hemorrhagic cystic mastopathy in 3.8%) long-term therapy with tibolone seemed to be well tolerated, and appeared to have a beneficial effect on the levels of serum lipids.