Long-term effects of combined hormone replacement therapy on markers of endothelial function and inflammatory activity in healthy postmenopausal women

The benefits and risks of menopause hormone therapy for the cardiovascular system in postmenopausal women: a systematic review and meta-analysis

BACKGROUND

Menopause hormone therapy (MHT), as an effective method to alleviate the menopause-related symptoms of women, its benefits, risks, and potential influencing factors for the cardiovascular system of postmenopausal women are not very clear.

OBJECTIVES

To evaluate cardiovascular benefits and risks of MHT in postmenopausal women, and analyze the underlying factors that affect both.

SEARCH STRATEGY

The EMBASE, MEDLINE, and CENTRAL databases were searched from 1975 to July 2022.

SELECTION CRITERIA

Randomized Clinical Trials (RCTs) that met pre-specified inclusion criteria were included.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data independently. A meta-analysis of random effects was used to analyze data.

MAIN RESULTS

This systematic review identified 33 RCTs using MHT involving 44,639 postmenopausal women with a mean age of 60.3 (range 48 to 72 years). There was no significant difference between MHT and placebo (or no treatment) in all-cause death (RR = 0.96, 95%CI 0.85 to 1.09, I2 = 14%) and cardiovascular events (RR = 0.97, 95%CI 0.82 to 1.14, I2 = 38%) in the overall population of postmenopausal women. However, MHT would increase the risk of stroke (RR = 1.23, 95%CI 1.08 to 1.41,I2 = 0%) and venous thromboembolism (RR = 1.86, 95%CI 1.39 to 2.50, I2 = 24%). Compared with placebo, MHT could improve flow-mediated arterial dilation (FMD) (SMD = 1.46, 95%CI 0.86 to 2.07, I2 = 90%), but it did not improve nitroglycerin-mediated arterial dilation (NMD) (SMD = 0.27, 95%CI - 0.08 to 0.62, I2 = 76%). Compared with women started MHT more than 10 years after menopause, women started MHT within 10 years after menopause had lower frequency of all-cause death (P = 0.02) and cardiovascular events (P = 0.002), and more significant improvement in FMD (P = 0.0003). Compared to mono-estrogen therapy, the combination therapy of estrogen and progesterone would not alter the outcomes of endpoint event. (all-cause death P = 0.52, cardiovascular events P = 0.90, stroke P = 0.85, venous thromboembolism P = 0.33, FMD P = 0.46, NMD P = 0.27).

CONCLUSIONS

MHT improves flow-mediated arterial dilation (FMD) but fails to lower the risk of all-cause death and cardiovascular events, and increases the risk of stroke and venous thrombosis in postmenopausal women. Early acceptance of MHT not only reduces the risk of all-cause death and cardiovascular events but also further improves FMD, although the risk of stroke and venous thrombosis is not reduced. There is no difference in the outcome of cardiovascular system endpoints between mono-estrogen therapy and combination therapy of estrogen and progesterone.

How do you decide on hormone replacement therapy in women with risk of venous thromboembolism?

Women are increasingly encouraged to participate in making decisions about hormone replacement therapy (HRT). In postmenopausal women with severe vasomotor symptoms, HRT can significantly improve the quality of life. However, the use of HRT may also increase the risk of venous thromboembolism (VTE), the risk which depends of both treatment-related and patient-related factors. This review summarizes some important points about the selection of the safest hormonal replacement modality in women with a history of VTE and management of VTE risks in postmenopausal women wishing to take HRT.

Low-dose oral or non-oral hormone therapy: effects on C-reactive protein and atrial natriuretic peptide in menopause

OBJECTIVE

To assess the effects of oral low-dose and non-oral hormone therapy (HT) on ultra-sensitive C-reactive protein (CRP), atrial natriuretic peptide (ANP), and cardiovascular risk factors in postmenopause.

METHODS

In this randomized, cross-over study, 44 recently postmenopausal women, with no clinical evidence of cardiovascular disease, received oral low-dose HT (estradiol 1 mg + drospirenone 2 mg/day) for 3 months. Forty-two patients received non-oral, conventional HT (1.5 mg/day percutaneous 17β-estradiol gel or equivalent for nasal route) for 3 months followed by 200 mg/day micronized progesterone by the vaginal route (14 days during each menstrual period). After 3 months, patients were crossed over without washout. Post-HT vs. pre-HT measures were determined: lipids, glucose, body mass index, waist circumference, fibrinogen, CRP-stratified levels, and ANP levels. The study was registered at clinical trials.gov (NCT01432028).

RESULTS

The mean age was 51 ± 3 years and the mean time since the menopause was 22 ± 10 months. CRP-stratified high levels decreased in a higher number of non-oral HT patients, who moved to intermediate and low levels (p = 0.02). No effect of HT was observed on ANP levels (baseline 67.4 (18.4-104.5), low-dose oral 43.5 (14.4-95.9), non-oral 39.8 (15.5-67.5) pg/ml). Markers of endothelial function did not worsen with either low-dose oral or non-oral HT: von Willebrand factor (baseline 118 ± 37%, low-dose oral 119 ± 38%, non-oral 108 ± 3%, p < 0.01), fibrinogen (baseline 356 ± 58 mg/dl; low-dose oral 343 ± 77 mg/dl; non-oral 326 ± 71 mg/dl, p < 0.01).

CONCLUSIONS

Low-dose oral and non-oral HT for 6 months had neutral or beneficial effects in recently postmenopausal women with no clinical evidence of cardiovascular disease.

The effect of hormone therapy on biochemical and ultrasound parameters associated with atherosclerosis in 46,XY DSD individuals with female phenotype

The aim of this study was to evaluate the effect of hormone therapy (HT) in the endothelial function of 46,XY disorders of sexual development (DSD) patients with female phenotype. Biochemical and ultrasound measurements were performed in 20 patients at initiation of oral 2 mg 17β-estradiol/1 mg norethisterone acetate, and after 6 months of therapy. Lipid profile, including total cholesterol (TC), LDL, HDL, triglycerides (TG) and Atherogenic Index of Plasma (AIP), as well as levels of VE-Cadherin, E-Selectin, Thrombomodulin and vWf were determined. Ultrasonographic examinations included evaluation of flow-mediated dilatation (FMD) and measurement of Carotid and Femoral Intima Media Thickness (IMT). HT raised HDL (35.4 mg/dl versus 40.1 mg/dl, p = 0.019) while lowering TG (166 mg/dl versus 109 mg/dl, p = 0.026) and AIP (0.24 versus 0.04, p = 0.007). No changes were noted in TC and LDL (215.7 mg/dl versus 192.25 mg/dl and 87.46 mg/dl versus 76.35 mg/dl, respectively). There was significant reduction of VE-Cadherin (4.05 ng/ml versus 2.20 ng/ml, p = 0.002) and E-selectin (73.98 ng/ml versus 56.73 ng/ml, p = 0.004). No change was observed in Thrombomodulin and vWf (11.76 ng/ml versus 13.90 ng/ml and 80.75% versus 79.55%, respectively). FMD improved significantly (5.4% versus 8.15%, p = 0.003), while only carotid bulb IMT decreased significantly (0.65 mm versus 0.60 mm, p = 0.018). Overall, HT was found to improve biochemical and ultrasound markers of endothelial function in 46,XY DSD patients with female phenotype.

Differential regulation of endothelium behavior by progesterone and medroxyprogesterone acetate

Medroxyprogesterone acetate (MPA) is a synthetic progestin commonly used in hormone replacement therapy (HRT). The aim of this research was to study and compare the effect of progesterone (Pg) and MPA on the regulation of cellular events associated with vascular homeostasis and disease. Platelet adhesion to endothelial cells (ECs), nitric oxide (NO) production, and cell migration were studied using murine ECs in vitro exposed to the progestins. After 7 min of treatment, MPA significantly inhibited NO synthesis with respect to control values; meanwhile, Pg markedly increased vasoactive production. In senile ECs, the stimulatory action of Pg decreases; meanwhile, MPA maintained its ability to inhibit NO synthesis. The presence of RU486 antagonized the action of each steroid. When ECs were preincubated with PD98059 (MAPK inhibitor) or chelerythrine (protein kinase C (PKC) inhibitor) before Pg or MPA treatment, the former totally suppressed the steroid action, but the PKC antagonist did not affect NO production. In the presence of a PI3K inhibitor (LY294002), a partial reduction in Pg effect and a reversal of MPA action were detected. Using indomethacin, the contribution of the cyclooxygenase (COX) pathway was also detected. On platelet adhesion assays, Pg inhibited and MPA stimulated platelet adhesion to ECs. Under inflammatory conditions, Pg prevented platelet adhesion induced by lipopolysaccharide (LPS); meanwhile, MPA potentiated the stimulatory action of LPS. Finally, although both steroids enhanced migration of ECs, MPA exhibited a greater effect. In conclusion, the data presented in this research provide evidence of a differential regulation of vascular function by Pg and MPA.

Distribution and determinants of C-reactive protein in the older adult population: European Prospective Investigation into Cancer-Norfolk study

BACKGROUND

C-reactive protein (CRP) is a well-documented predictor of cardiovascular diseases and mortality. We aimed to better understand the distribution and determinants of CRP in the population.

MATERIALS AND METHODS

Study participants were men and women aged 40-79 in the UK-based EPIC-Norfolk population-based cohort study. CRP was measured in 18 586 available serum samples (8334 men and 10 252 women) and remeasured in 6087 individuals on average 13 years later using a high-sensitivity assay.

RESULTS

In cross-sectional analyses, the range of serum CRP was 0.1-188.3 mg/L and the median 1.6 mg/L. A third of the population had serum CRP levels above 3 mg/L. Serum CRP levels were comparable in men and women who were not taking postmenopausal hormone replacement therapy (HRT). Women who were taking HRT had double CRP levels compared with HRT nonusers. Smoking was also strongly related to CRP in men and women. Serum CRP was positively and independently associated with age, body mass index and waist circumference and inversely with height. A stronger association with serum CRP measured concurrently than on average 13 years later indicated a short-term rather than long-term association with smoking and HRT use. Social class and alcohol intake were not independently related to CRP, but there was a strong inverse association with educational status.

CONCLUSION

The distribution of serum CRP in the population is similar in men and women after taking into account smoking and HRT use. Anthropometric factors as well as educational status are strongly related to serum CRP.

1 and 2 mg 17β-estradiol combined with sequential dydrogesterone have similar effects on the serum lipid profile of postmenopausal women

OBJECTIVES

The aim of this study was to assess the effects of 1 and 2 mg 17beta-estradiol on serum lipid profile. Beneficial effects have been clearly established in previous studies with a 2 mg dose; further evidence was required to confirm the beneficial effects of a 1 mg dose.

METHODS

This double-blind, placebo-controlled study involved 579 postmenopausal women randomized to oral treatment with placebo, 1 mg/day 17beta-estradiol sequentially combined with 5 or 10 mg/day dydrogesterone for the last 14 days of each 28-day cycle, or 2 mg/day 17beta-estradiol sequentially combined with 10 or 20 mg/day dydrogesterone for the last 14 days of each 28-day cycle. Treatment was continued for 26 cycles.

RESULTS

High density lipoprotein (HDL) cholesterol levels were significantly (p<0.05) increased after 26 cycles in all active treatment groups compared with placebo. In addition, low density lipoprotein (LDL) cholesterol and lipoprotein(a) levels were significantly reduced, and apolipoprotein A1 and triglyceride levels were significantly increased, in all active treatment groups after 13 and 26 cycles.

CONCLUSIONS

The results of this study clearly indicate that sequential combinations of either 1 or 2 mg 17beta-estradiol with dydrogesterone are associated with long-term, favorable changes in the serum lipid profile. There was no evidence that dydrogesterone compromised the 17beta-estradiol-induced improvements in lipid profile.

Effects of hormone therapyon C-reactive protein and IL-6 in postmenopausal women: a review article

The results of the Women's Health Initiative, showing an increase in coronary heart disease events in postmenopausal women on estrogen and medroxyprogesterone acetate, have created considerable interest in finding an underlying mechanism that may confer cardiovascular risk in women on hormone therapy (HT). Inflammation is thought to play a key role in the progression of atherosclerosis. C-reactive protein (CRP) is an inflammatory marker that has been studied as a predictor of future coronary risk. Interleukin 6 (IL-6) is felt to be an important cytokine in the inflammatory cascade and instrumental in CRP expression. The purpose of this article is to summarize the observational and randomized studies that examine the difference in IL-6 and CRP concentrations with respect to oral versus transdermal hormone therapy. We also review studies looking at differences in CRP levels based on the progestin component of HT and trials examining the effect of estrogen agonists on IL-6 and CRP. In our review, we found CRP levels to be elevated in the majority of postmenopausal women on oral HT. There was no correlation between IL-6 and CRP levels. Studies examining the effect of progestins produced varying results. Transdermal estrogen, in contrast, showed no elevation in levels of IL-6 or CRP alone or with the addition of progestins. Selective estrogen receptor agonists (SERMs) did not demonstrate an effect on CRP levels, although tibolone did increase CRP in one reviewed trial. Questions remain about the role of progestins and transdermal HT therapy in the inflammatory process and the underlying mechanism of CRP activation. More research is needed to understand how HT may be involved in the inflammatory process.

Imunossenescência: a relação entre leucócitos, citocinas e doenças crônicas

RESUMO O processo de envelhecimento e sua conseqüência natural – a velhice – constituem uma das maiores preocupações da sociedade moderna, sobretudo devido ao rápido crescimento da parcela idosa da população com relação aos demais grupos etários. Esse crescimento traz mudanças para nossa civilização e desafia a sociedade em diferentes aspectos, especialmente naqueles relativos à saúde humana. Este último talvez seja o mais enfatizado e preocupante, já que a maioria dos idosos apresenta ao menos uma doença crônica e limitações de saúde. Sob o caráter biológico, o processo de envelhecimento é um fenômeno complexo que submete o organismo a inúmeras alterações fisiológicas, afetando sua integridade e permitindo o surgimento das doenças crônicas na velhice, com impacto sobre a saúde e a qualidade de vida do idoso. Dentre os sistemas do organismo, os que mais sofrem efeitos do envelhecimento são o nervoso, o endócrino e o imunológico. Nesta revisão, o processo de envelhecimento é abordado sob a ótica das alterações do sistema imunológico conhecidas como o fenômeno da imunossenescência. São analisados aspectos relacionados a alterações numéricas, morfológicas e funcionais dos diferentes tipos celulares que compõem o sistema, com ênfase para os efeitos biológicos dos principais mediadores inflamatórios (citocinas) para o surgimento das doenças crônico-degenerativas presentes no envelhecimento.

The role of estrogen in the formation of experimental abdominal aortic aneurysm

OBJECTIVE

The current study sought to investigate the role of estrogen in the formation of experimental abdominal aortic aneurysm (AAA).

METHODS

Elastase perfusion of infrarenal AAA animal model was performed in 20 female and 20 male Wistar rats that were randomly divided into an ovariectomized/sham-operated group and an estradiol (E2) experimental/saline control group, respectively. At day 14, E2 was detected, while the mRNA and protein expressions of matrix metalloproteinases 2 and 9 (MMP-2 and -9) in AAA tissue were detected by immunohistochemistry and polymerase chain reaction (PCR).

RESULTS

The ovariectomized group showed lower estrogen levels and a higher aneurysm dilatation rate and significantly higher MMP-2 and -9 expression compared with the sham-operated group (P < .01), which was in accordance with MMP-2 and -9 mRNA expression. The E2 group showed higher estrogen levels and a lower aneurysm dilatation rate and significantly lower MMP-2 and -9 expression than did the saline control group (P < .01), which was in accordance with MMP-2 and -9 mRNA expression.

CONCLUSIONS

In the pathogenesis of AAA, estrogen may play an inhibitory role by decreasing expression of MMP-2 and MMP-9 synthesis.

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.

John JA, Xiang M, Cushman M, Lobo RA, Mack WJ. Inflammatory markers and progression of subclinical atherosclerosis in healthy postmenopausal women (from the Estrogen in the Prevention of Atherosclerosis Trial)

The objective of this study was to determine whether high-sensitivity C-reactive protein (hs-CRP) and serum soluble intercellular adhesion molecule-1 (sICAM-1) correlate with progression of subclinical atherosclerosis. Secondarily, the long-term effect of oral estradiol on hs-CRP and sICAM-1 were determined. Data were analyzed from 180 healthy postmenopausal women aged 45 to 80 years randomly assigned to either unopposed micronized 17beta-estradiol 1 mg/day or placebo in the Estrogen in the Prevention of Atherosclerosis Trial (EPAT). Carotid artery intima-media thickness (CIMT), hs-CRP, and sICAM-1 were measured at baseline and every 6 months thereafter for 2 years. Unopposed 17beta-estradiol significantly increased hs-CRP (p = 0.01) and decreased sICAM-1 compared with placebo (p = 0.04). Changes in hs-CRP and sICAM-1 did not correlate with changes in carotid artery intima-media thickness. In conclusion, although unopposed 17beta-estradiol significantly altered hs-CRP and sICAM-1, neither marker was associated with progression of subclinical atherosclerosis.

Low-dose continuous combinations of hormone therapy and biochemical surrogate markers for vascular tone and inflammation: transdermal versus oral application

OBJECTIVE

To compare the effects of low-dose transdermal estradiol (E2)/norethisterone acetate (NETA) patches (Estalis 25/125) with low-dose oral E2/NETA (Activelle) on cardiovascular biochemical markers after 12 and 52 weeks of treatment in postmenopausal women with intact uteri.

DESIGN

Participants were randomly assigned to receive either transdermal E2/NETA (delivering daily doses of 25 microg E2 and 125 microg NETA, applied every 3-4 d) or oral E2/NETA (1 mg E2 and 0.5 mg NETA, given daily) in this open-label study. The following markers or their stable metabolites in serum or urine were assessed: P-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, matrix metalloproteinase-9, homocysteine, cyclic guanosine monophosphate, serotonin, prostacyclin, thromboxane, and urodilatin.

RESULTS

Significant decreases were found for P-selectin, intercellular adhesion molecule-1, monocyte chemoattractant protein-1, and homocysteine for both hormone therapy (HT) regimens compared with baseline. Matrix metalloproteinase-9 was increased only by oral HT. The urinary concentrations of cyclic guanosine monophosphate, the ratio of prostacyclin to thromboxane metabolite, and the serotonin metabolite were significantly increased for both HT application modes, although the oral treatment showed a significantly greater increase than the transdermal one with respect to baseline. Urodilatin excretion was increased only by the oral regimen.

CONCLUSIONS

Low-dose transdermal and oral HTs using E2 and NETA elicit favorable effects on cardiovascular biochemical markers. For most markers the magnitude of changes found were similar with respect to baseline; however, in some cases oral HT led to a significantly greater change, whereas in other cases the transdermal formulations seemed to provide greater benefits. Whether these differences may be attributed to the different administration routes or to different pharmacokinetic properties remains an open question. Overall low-dose transdermal HT seems to provoke the same benefit on the cardiovascular system as oral HT, as suggested by the results on vascular markers.

Time since menopause influences the acute and chronic effect of estrogens on endothelial function

OBJECTIVE

We evaluated whether time since menopause influences the acute and chronic effect of Estradiol (E) on vascular endothelial function.

METHODS AND RESULTS

We studied flow-mediated dilatation (FMD) in 134 postmenopausal women (PMW) before and after acute and chronic E administration. At baseline FMD was inversely associated to time from menopause (r=-0.67, P<0.001) and age (r=-0.43, P<0.05), in exogenous estrogen naïve but not in previous users. Acute and chronic E improved endothelial function in all women. E administration improved FMD more in women within 5 years since menopause than in those with more than 5 years since menopause (76% and 74% versus 45% and 48%, acute and chronic E, respectively; P<0.05). Among women with more than 5 years since menopause acute and chronic E increased FMD more in previous E users than in nonusers (59% and 63% versus 31% and 38%, acute and chronic E, respectively; P<0.01). Multivariate analysis showed that time from menopause was a predictor of impaired FMD and of its improvement after acute and chronic E.

CONCLUSIONS

Time from menopause influences FMD in PMW. The acute and chronic effect of E on FMD is time dependent and is reduced by a longer time since menopause.

Effect of Hormone Therapy on Exercise Capacity in Early Postmenopausal Women

OBJECTIVE

To compare the exercise capacity of postmenopausal women with matched premenopausal controls, as well as postmenopausal women before and after 3 months of hormone therapy (HT).

METHODS

This study examined the response to strenuous isotonic exercise in 30 women with recently developed menopause (age, mean+/-standard deviation, 50.6+/-1.1 years) without cardiovascular risk factors or diseases. Thirty premenopausal subjects, matched one-to-one for age and biophysical characteristics, were the control group. Postmenopausal women underwent examination before (T(0)) and 3 months after (T(1)) HT (oral 0.625 mg conjugated estrogen and 2.5 mg medroxyprogesterone acetate/day) with high-resolution ultrasound determination of peripheral flow-mediated vasodilation and an integrative cardiopulmonary test.

RESULTS

Postmenopausal women showed an impairment of flow-mediated vasodilation (P<.001) in the radial artery and a worsening of physical performance, primarily exemplified by lower maximal workload (P<.01) and peak oxygen consumption (Vo(2)max, P<.001) compared with premenopausal women. After 3 months on HT, ergometabolic parameters and vasodilation reserve were at a level comparable to premenopausal women. Flow-mediated vasodilation measurements after 3 months on HT significantly correlated with those of peak oxygen consumption (r=0.77, P<.001) and the ratio between the increase in oxygen consumption and that in work rate (DeltaVo(2)/DeltaWR) (r=0.73, P<.001).

CONCLUSION

The peripheral circulation is the limiting system in postmenopausal women experiencing exercise intolerance, and there are benefits in introducing HT.

Effects of dydrogesterone on the vascular system

Estrogens exert beneficial effects on the vascular system, while progestogens generally have a negative impact (e.g. vasoconstrictor effects on the arterial system). In contrast, dydrogesterone appears to be largely neutral in terms of biochemical markers and indirect clinical endpoints, such as blood pressure, that act as surrogate markers for vascular function. Studies on lipid and carbohydrate metabolism, which can also influence vascular function, demonstrate that the addition of dydrogesterone intensifies rather than attenuates beneficial estrogenic effects. Dydrogesterone also has largely neutral effects on hemostasis. Since there are relatively few data available on clinical parameters such as blood flow measurements, especially in women with pre-existing cardiovascular diseases, increased risks cannot be excluded for a combination of estrogen replacement with dydrogesterone. Further studies should focus on this open question since dydrogesterone, with its largely neutral properties, might be a suitable option, including for older women already at increased cardiovascular risk.

Long-term effects of tibolone on circulating levels of vascular cell adhesion molecules and E-selectin in postmenopausal women

OBJECTIVE

Adherence of lymphocytes and monocytes to cell adhesion molecules (vascular cell adhesion molecules [VCAMs]) expressed by activated endothelial cells is the first step in the development of atherosclerotic disease. It is known that administration of tibolone for 8 weeks reduces serum levels of VCAMs in postmenopausal women. We evaluated the effects of the administration of tibolone in postmenopausal women for 1 year.

DESIGN

Randomized, placebo-controlled, crossover trial.

SETTING

Healthy volunteers in an academic environment.

PATIENT(S)

Thirty-six healthy women in postmenopause since 1-4 years.

INTERVENTION(S)

Group A received 2.5 mg/d of tibolone and group B received placebo for 12 months; treatment was subsequently crossed over for 1 month.

MAIN OUTCOME MEASURE(S)

Serum concentrations of VCAM-1, intercellular adhesion molecule-1 (ICAM-1), and E-selectin were evaluated at baseline and at 6, 12, and 13 months.

RESULT(S)

Baseline concentration of VCAM-1, ICAM-1, and E-selectin were similar in both groups. At months 6 and 12, mean concentrations of VCAM-1, ICAM-1, and E-selectin decreased significantly in group A but not in group B. At month 13, levels returned to baseline in group A, whereas they decreased significantly in group B.

CONCLUSION(S)

Tibolone causes a rapid and sustained decrease in circulating levels of VCAMs; the effect is lost soon after stopping the treatment. Tibolone induces favorable changes in endothelial function and may exert a direct cardiovascular protective effect in postmenopausal women.

The effect of hormone replacement therapy on the levels of serum lipids, apolipoprotein AI, apolipoprotein B and lipoprotein (a) in Turkish postmenopausal women

OBJECTIVES

Estrogen replacement therapy alters the lipid profiles favorably for delaying atherosclerosis in postmenopausal women. The effects of estrogen plus progesterone combination therapy on lipids are controversial. This study was designed to evaluate the effect of female sex hormones on lipids and lipoproteins and to clarify the influence of progesterone on the effect of estrogen in postmenopausal women.

METHODS

Of the 60 postmenopausal women admitted to our menopause clinic, 40 had intact uterus and received continuous 0.625 mg conjugated equine estrogen (CEE) plus 2.5 mg medroxyprogesterone acetate (MPA), whereas the remaining 20 were hysterectomized and received 0.625 mg CEE daily. To assess the alterations in lipids and lipoproteins during menopause, 45 healthy premenopausal women were investigated. Lipid and lipoprotein levels were assessed in each subject at baseline and at the 6th and 18th months of therapy.

RESULTS

In menopause, a shift towards more atherogenic lipid and lipoprotein profiles than those of the premenopausal state was found. Following 18 months of treatment, both regimens reduced total cholesterol (TC) levels as compared with the baseline (6.4 vs. 6.9% in the CEE/MPA and CEE groups, respectively). The CEE group had a more pronounced increase in high-density lipoprotein (HDL) cholesterol than the CEE/MPA group (10.3 vs. 8.8%, respectively). Both groups displayed reduced TC, low-density lipoprotein (LDL) cholesterol and apolipoprotein-B (ApoB) concentrations, whereas triglycerides increased, with a greater tendency to increase in the CEE/MPA group at the end of the trial. Also, the lipoprotein (a) [Lp(a)] levels decreased significantly (27.6 vs. 24.5% in the CEE/MPA and CEE groups, respectively). This decrease was more pronounced in subjects with a relatively higher basal Lp(a) concentration.

CONCLUSION

Both treatment regimens caused positive alterations in the lipid and lipoprotein profiles. This association might play a pivotal role in the postmenopausal increases in atherosclerotic diseases and cardioprotective effect of estrogen in postmenopausal women.

Effects of dydrogesterone and norethisterone, in combination with oestradiol, on lipoproteins and inflammatory markers in postmenopausal women

OBJECTIVE

The lack of cardiovascular benefit from postmenopausal hormone replacement therapy (HRT) in randomised controlled trials is not readily explained. The androgenic properties of progestogens could be crucial in understanding the results of these studies, all of which employed medroxyprogesterone. We have previously reported that medroxyprogesterone has some androgenic effects intermediate between those of the more androgenic norethisterone and the less androgenic desogestrel. To examine the androgenicity of progestogens further, we compared the effects of dydrogesterone (DGT) that is even less androgenic than desogestrel, and norethisterone (NET), on lipoproteins and inflammatory markers while maintaining the same oestrogen dose.

METHOD

In a crossover trial, 25 non-hysterectomised postmenopausal women were randomised to two preparations of HRT each for three 28-day treatment cycles. Both HRT regimens comprised oestradiol (1mg). One also included DGT (10mg) and the other NET (1mg). Oestradiol was taken continuously and the progestogens sequentially. Measurements were made at baseline and on the last day of the oestradiol phase and the last day of the progestogen phase in the third treatment cycle of each regimen.

RESULTS

NET was more effective than DGT in significantly reducing lipoprotein (a) (p < 0.05). NET was, however, associated with significantly lower levels of high-density lipoprotein (HDL) cholesterol (p = 0.001) and triglycerides (p < 0.05). NET was less effective in opposing the oestrogen-related increase in C-reactive protein (CRP). Interleukin-6 levels did not change with either progestogen.

CONCLUSION

The effect of androgenic progestogens on cardiovascular risk factors may not be as deleterious as previously assumed, especially if the lower HDL levels result from more efficient reverse cholesterol transport. The hormone related rise in C-reactive protein, without a corresponding increase in interleukin-6, may not represent a systemic inflammatory response.

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.

The effect of raloxifene and tibolone on the uterine blood flow and endometrial thickness: A transvaginal Doppler study

OBJECTIVES

To evaluate and compare the effect of different than classical hormone therapy medications, such as raloxifene and tibolone, on the uterine arteries and endometrium of postmenopausal women using transvaginal ultrasonography.

METHODS

The prospective study included 62 healthy, postmenopausal women recruited from the Menopausal Clinic of the 2nd Department of Obstetrics and Gynecology of the University of Athens. Subjects were randomly allocated to receive raloxifene HCl in a daily dose of 60 mg orally (Group A-31 women) or tibolone in a daily dose of 2.5 mg orally (Group B-31 women). The study period was 6 months and all subjects were assessed using transvaginal ultrasonography before treatment initiation as well as after 3 and 6 months for evaluation of the endometrial thickness and the pulsatility (PI) and resistance (RI) indices at the level of the uterine arteries.

RESULTS

No significant differences in RI, PI and endometrial thickness were observed in the raloxifene group during the 6-month treatment. In the tibolone group, PI and RI values decreased linearly from baseline to the end of the study, whereas the endometrial thickness was significantly increased during the first 3 months remaining unaltered thereafter. Comparisons between the two study groups revealed significant percent change of values in the pre-treatment to month-3 period and no difference with regard to pre-treatment, month-3 and month-6 absolute values.

CONCLUSION

Raloxifene and tibolone exert dissimilar effects on uterine blood supply parameters and endometrial thickness.

Emerging Selective Estrogen Receptor Modulators

Menopause, regardless of age at onset, is associated with a marked increase in coronary heart disease (CHD) risk. On the basis of epidemiological studies that demonstrated mainly positive effects of postmenopausal hormone therapy on CHD as well as on risk markers of CHD, it has been suggested that CHD could be prevented in postmenopausal women with long-term hormone therapy. However, since the publications of the Heart and Estrogen/progestin Replacement Study and the Women's Health Initiative trial, prescription of hormone therapy for the prevention of CHD has become controversial. Major efforts have been made to identify alternatives for hormone therapy. Compounds suggested have included selective estrogen receptor modulators (SERMs), which represent a class with a growing number of compounds that act as either estrogen receptor agonists or antagonists in a tissue-specific manner. This pharmacological profile may offer the opportunity to dissociate favourable estrogenic effects on the bone and cardiovascular system from unfavourable stimulatory effects on the breast and endometrium. Two SERMs presently on the market are tamoxifen and raloxifene. The only data available regarding the effects of tamoxifen on cardiovascular events in postmenopausal women are from breast cancer trials. These trials found fewer fatal myocardial events in women randomly assigned to tamoxifen compared with women assigned to placebo. Raloxifene is a second-generation SERM that has been shown to prevent osteoporotic fractures, is safe for the endometrium and holds high promise for the prevention of breast cancer. The effect of raloxifene on CHD is still uncertain. On the basis of the MORE (Multiple Outcomes of Raloxifene Evaluation) trial, raloxifene may offer some protection to women with CHD or to those who are at high risk of CHD. Proof that raloxifene reduces the risk of CHD requires a clinical trial with hard clinical endpoints. Such a study is currently underway. Next-generation SERMs taken into clinical development include idoxifene, droloxifene, ospemifene, arzoxifene, acolbifene/EM-800, levormeloxifene, lasofoxifene, bazedoxifene and HMR 3339. The aim is to find a compound with the ideal profile, that is, alleviation of climacteric symptoms and prevention of osteoporotic fractures, but without an adverse effect on the breast and endometrium, and no negative effect or even a beneficial effect on the cardiovascular system and the brain. Currently, limited data are available with regard to these next-generation SERMs and CHD. Nevertheless, some of these novel agents provide arguments for continuing the search for an ideal SERM.

Association of Endogenous Hormones with C-reactive Protein, Fibrinogen, and White Blood Count in Post-menopausal Women

Oral exogenous estrogen raises C-reactive protein (CRP) concentrations, but the impact of endogenous hormones is unknown. We examined the cross-sectional relation of several serum hormones with CRP, fibrinogen, and white blood cell count - three inflammatory markers linked prospectively to coronary artery disease. Serum hormones were measured on a sample (n = 317) of postmenopausal female participants, with or without carotid intima-media thickening, in the Atherosclerosis Risk in Communities (ARIC) Study. Fibrinogen and white blood cell count were available on all and CRP in a subset (n = 57). Adjusted for age, race, and case-control status, mean CRP was 2-fold greater in the highest vs. lowest quartiles of estrone and androstenedione, and CRP was 2-fold less across quartiles of sex hormone binding globulin. These associations were not all statistically significant with this sample size. Fibrinogen and white blood cell count also were associated positively with estrone, androstenedione, and testosterone (and fibrinogen also with dehydroepiandrosterone sulfate). Adjustment for other risk factors and especially body mass index, a known determinant of endogenous hormone levels, attenuated most associations. In conclusion, several endogenous sex hormones may influence basal levels of inflammatory markers. Obesity appears to play a modulating role.

The effects of oral and transdermal hormone replacement therapy on C-reactive protein levels and other inflammatory markers in women with high risk of thrombosis

INTRODUCTION

In the estrogen in venous thromboembolism (EVTET) study of 140 women with a history of venous thromboembolism (VTE), oral hormone replacement therapy (HRT) was associated with strong activation of coagulation markers and increased risk of recurrent VTE. No such associations were observed in the estrogen women atherosclerosis (EWA) study of 118 women with established coronary artery disease who were given transdermal HRT.

OBJECTIVES AND METHODS

The aim of the present study was to evaluate the effects of oral and transdermal HRT on levels of C-reactive protein (CRP), which was assayed with a highly sensitive method. We also evaluated the effects on other inflammatory markers and the influence of possible confounding factors.

RESULTS

Oral HRT was associated with a significant increase in CRP after 3 months as compared with placebo (median 79% [95% confidence interval 36-119%] versus -4% [-13 to 10%], p = 0.001). These changes sustained after 12 months. Among those allocated HRT, the median increase in CRP was higher in women who subsequently developed recurrent thrombosis (median 328%, n = 5, versus 54%, n = 60). TNF-alpha levels decreased significantly by mean -10% [-15 to -5%] versus 3% [-4 to 10%], p=0.004. Soluble VCAM-1 decreased in the HRT group compared to the placebo group (mean -13% [-18 to -8%] versus 1%, [-3 to 5%], p < 0.001). There were no significant changes in levels of IL-6, TGF-beta or P-selectin. On transdermal HRT no significant changes in CRP were observed after 3 and 12 months of treatment.

CONCLUSIONS

Our findings substantiate that oral HRT containing estradiol is associated with a marked and rapid increase in CRP, whereas transdermal treatment is not. However, this increase on oral treatment was associated with no increases of other inflammatory markers.

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.

Different effect of hormone replacement therapy, DHEAS and tibolone on endothelial function in postmenopausal women with increased cardiovascular risk

Menopause is associated with an increased cardiovascular risk and with a decrease in endothelial function. Hormone replacement therapy (HRT) improves endothelial function in post-menopausal women (PMW) without established atherosclerosis. New alternative treatments, among which tibolone (T) and DHEAS have been suggested to reduce postmenopausal cardiovascular risk. Although, in vitro animal studies have suggested that T and DHEAS improve endothelial function, their effect in humans has never been tested. The aim of the present study was to compare the effects of HRT (continuous combined 0.625 mg conjugated equine estrogen plus 2.5 mg/d medoxyprogesterone) DHEAS and T on endothelium-dependent flow-mediated vasodilatation (FMD), plasma nitrite, nitrate and endothelin-1 levels in 16 PMW with increased cardiovascular risk in a double-blinded, double-crossover study. Women were randomized and treated for 4 weeks with HRT, T or DHEAS. Brachial artery diameter, FMD, endothelin-1 and plasma nitrite and nitrate levels were measured at baseline and after each treatment phase. Brachial artery diameters remained unchanged after each treatment phase. HRT significantly improved FMD compared to both baseline and to T and DHEAS therapies while no effect of T or DHEAS on FMD was noted. In conclusion, HRT, but neither T nor DHEAS, improves endothelial function and reduces plasma levels of endothelin-1 in PMW at risk of CAD.

Value of C-reactive protein levels and IL-6 in predicting events levels in women at increased cardiovascular risk

BACKGROUND

Elevated C-reactive protein (CRP) levels due to of heightened vascular inflammatory state in vascular conditions are often associated with elevated interleukin-6 (IL-6) levels since during inflammation CRP production in the liver is induced by IL-6. It has been suggested that CRP may be a predictors of unfavourable outcome in postmenopausal women (PMW) receiving hormone replacement therapy. Because of the possible metabolic effect of hormone replacement therapy (HRT) on CRP, the relative predictive importance of CRP and IL-6 levels in PMW receiving HRT remains to be elucidated.

METHODS

We measured plasma levels of CRP and IL-6 levels in 346 consecutive PMW (mean age 66+/-9 years) with cardiovascular risk >20 in 10 years followed during a 36 month period. Women underwent measurement of inflammatory cytokines at baseline and were allocated to two groups according to the willingness to take hormone replacement therapy. All women underwent a further measurement of CRP and IL-6 at 3 and 6 months. Health status was assessed by out patient visits and hospital charts.

RESULTS

During 1 year follow up, three patient died, four had a major cardiovascular event, three had a unstable angina, two had a transient ischemic attack and two patients underwent PTCA. PMW with events had higher CRP levels compared with patients with no events (1.9+/-0.61 versus 1.43+/-0.21, P<0.05) but still within the limits of normal. Also baseline IL-6 plasma levels were significantly higher in PMW with events than in those without events (0.87+/-0.23 versus 0.54+/-0.18, P <0.05). The increase in CRP and IL-6 with HRT was significantly higher in patients with events than in those with no events (CRP: 81+/-12 % versus 76+/-21%, P<0.05; IL-6 9+/-3 % versus -14+/-7%, P<0.05). In a stepwise multivariate analysis, IL-6 levels resulted a stronger predictor of outcome than CRP. CRP levels were predictors of future events only after removal of IL-6 levels and presence of cardiovascular symptoms from the analysis. CRP levels were associated with an unfavourable outcome only when IL-6 levels were also elevated. The increase in CRP with HRT during follow up was not associated to an increased event rate.

CONCLUSION

Our study showed that CRP levels are increased in PMW receiving HRT. Elevated IL-6 levels may identify those PMW at increased 1 year risk. CRP levels predict events only when they are coupled with elevated IL-6 levels.

HMR 3339, a novel selective estrogen receptor modulator, reduces total cholesterol, low-density lipoprotein cholesterol, and homocysteine in healthy postmenopausal women

OBJECTIVE

To investigate the short-term effects of HMR 3339 in comparison with raloxifene and placebo on cardiovascular risk factors.

DESIGN

A multicenter, randomized, placebo-controlled, double-blind, dose-ranging study.

SETTING

Gynecologic outpatient department.

PATIENT(S)

One hundred eighteen healthy nonhysterectomized postmenopausal women.

INTERVENTION(S)

Participants received daily placebo (n = 22), 2.5 mg of HMR 3339 (n = 25), 10 mg of HMR 3339 (n = 24), 50 mg of HMR 3339 (n = 24), or 60 mg of raloxifene (n = 23) for 12 weeks followed by a 2-week washout period.

MAIN OUTCOME MEASURE(S)

Blood concentrations of lipids measured at baseline, and after 2, 4, 8, 12, and 14 weeks, and of lipoprotein(a), homocysteine, and endothelin-1 measured at baseline, and after 4 and 12 weeks.

RESULT(S)

After 12 weeks of treatment with HMR 3339, compared with placebo, serum total cholesterol was reduced (10 mg of HMR 3339: -9.7%; 50 mg of HMR 3339: -15.2%), low-density lipoprotein (LDL)-cholesterol (10 mg of HMR 3339: -10.8%; 50 mg of HMR 3339: -24.2%) and plasma homocysteine concentrations (2.5 mg of HMR 3339: -3.9%; 10 mg of HMR 3339: -10.8%; 50 mg of HMR 3339: -13.8%), suggesting a dose-dependent effect of HMR 3339. These effects were already apparent after 2 weeks of treatment for total cholesterol and LDL-cholesterol, and after 4 weeks of treatment for homocysteine. After 12 weeks, raloxifene, compared with placebo, significantly decreased total cholesterol (-10.5%), LDL-cholesterol (-15.0%), and triglycerides (-16.9%), but not homocysteine. High-density lipoprotein-cholesterol, lipoprotein(a), and endothelin-1 showed no significant changes in any of the active treatment groups.

CONCLUSION(S)

HMR 3339 reduces total cholesterol, LDL-cholesterol, and homocysteine concentrations in postmenopausal women.

Effect of hormone therapy on BP in normotensive and hypertensive postmenopausal women

High blood pressure (BP) ranks as the greatest risk factor for cardiovascular disease. The increased cardiovascular risk determined in recent interventional studies has led the health authorities in some countries to re-ignite the discussion about whether hypertension should be listed as a contraindication for hormone replacement therapy (HRT). We reviewed papers published since 1960 and listed in MEDLINE, EMBASE and Biosis, on studies that monitored the course of BP during HRT. We found that both primarily normotensive and hypertensive postmenopausal women actually run only a very low risk of BP increase during HRT, indeed, BP was often lowered. In one of our own studies 1397 hypertensive women with BP diastolic >95 mmHg received transdermal HRT regimens; BP was lowered by an average of 7 mmHg systolic and 9 mmHg diastolic. The results of the more recent 24-h ambulatory BP studies are particularly conclusive. At least 19 such studies have been performed, 13 placebo-controlled and 10 cross-over; 5 found no effect on BP and 14 studies demonstrated BP reductions. BP was lowered by treatment with transdermal estradiol in 11 of 13 studies and by oral estrogen in 4 of 11 studies. The effects were not consistent with regard to systolic or diastolic BP nor to action on day- and night-time BP. It cannot be ruled out that some women with a particular predisposition exhibit an abnormal reaction to the vasoactive effects of HRT, and there is a paucity of long-term data on risk populations, specifically on the progestogenic effects in patients with pre-existing arteriosclerotic lesions. In conclusion, the risk of developing hypertension during HRT is very low, but hormone therapy should always be appropriately indicated and during therapy BP should be checked regularly.

The Effect of Different Doses of Micronized 17ss-Estradiol on C-Reactive Protein, Interleukin-6, and Lipids in Older Women

BACKGROUND

The authors evaluated the effect of 3 doses (0.25 mg/day, 0.5 mg/day, and 1 mg/day) of micronized 17beta-estradiol (E2) on C-reactive protein (CRP), interleukin-6 (IL-6), and lipids, compared with placebo, in healthy older women participating in an osteoporosis study.

METHODS

This randomized, double-blind, placebo-controlled study was conducted in a University clinical research center. Participants were healthy, community-living women older than 65 years. The primary outcome measure of the study was bone metabolism as estimated by serum and urine markers of bone turnover. For this analysis, the authors measured serum markers of CRP, IL-6, lipids, intracellular adhesion molecule-1, and E-selectin at baseline, after 12 weeks of treatment, and after 12 weeks with no treatment.

RESULTS

A significant dose-response effect of estrogen occurred on CRP levels. After 12 weeks of treatment, CRP decreased 59% in the 0.25 mg/day E2 group and increased 65% in the 1 mg/day E2 group, compared with placebo. The CRP level continued to be elevated (92%), compared with placebo, 12 weeks after treatment was discontinued in the 1 mg/day E2 group. High-density lipoprotein (HDL) and HDL2 cholesterol increased and low-density lipoprotein (LDL) cholesterol decreased at 12 weeks in the 1 mg/day E2 group, with a significant dose-response effect. E-selectin decreased significantly in the 1 mg/day E2 group 12 weeks after discontinuation of treatment (-7%), and there was a significant dose-response effect at this time. The 2 lower doses did not affect any of these parameters. Total and HDL3 cholesterol, triglycerides, lipoprotein(a), intracellular adhesion molecule-1, and IL-6 did not change with any dose of E2.

CONCLUSIONS

C-reactive protein, an inflammation marker associated with increased risk for cardiovascular disease, decreased in women taking the lowest estrogen dose but increased in women assigned to the highest estrogen dose, suggesting decreased inflammation with lower dose E2. However, with 3 months of treatment, 0.25 or 0.5 mg/day E2 did not have the same beneficial effects on HDL or LDL cholesterol as did 1 mg/day E2. These data suggest that estradiol doses have differential short-term effects on markers of cardiovascular disease. Low-dose E2 decreased CRP, an important marker of inflammation, but did not affect lipid parameters, whereas the highest dose increased CRP and had a beneficial effect on lipid parameters. The long-term consequences of these effects are unknown, but it is possible that estradiol dose should be considered when risk:benefit ratios are evaluated for individual women before estrogen replacement therapy is initiated.

Differential effects of progestins on hemostasis

Recently large, prospective, randomized studies on hormone replacement therapy (HRT) have indicated that the progestin use might interfere with hemostasis and thus increase venous thrombotic events. Therefore, available publications were evaluated to determine whether progestins interfere with hemostasis, either when given alone via oral or parenteral routes or in combination with ethinylestradiol as synthetic estrogen or natural estrogens. There are indications that such interference is dependent upon the type and dose of the progestin, the route of application, the length of treatment and the type and dose of the estrogen with which it is combined. For natural progesterone, no negative effects on the hemostatic system were seen with either oral or parenteral application, in cyclic or continuous regimens, for the doses investigated. Similarly, no unwanted effects were seen with progestin only pills (POP), independent of the type and dose of progestin, or parenteral progestins. With the high-dose progestins used in gynaecological oncology, the increased activation of the hemostatic system resulting from the disease itself has to be taken into account when looking at any increased incidence of thromboembolic events in these patients. For estrogen/progestin combinations, the risk of venous thromboembolism is attributed to the estrogen used. Recent studies showed an increased rate of thromboembolic events in association with desogestrel-and gestodene-containing oral contraceptives, compared with those containing levonorgestrel. With HRT, a decrease in antithrombin factors could explain the increased rate of venous thrombotic events. In conclusion, progestins seems to have different effects on the hemostatic system due to their different pattern of biological activities. This was also shown in the arterial vascular system, where some progestins may reduce the endothelium-dependent vasodilating action of estrogens and stimulate intima proliferation and upregulate thrombin receptor expression while other progestins did not.

Effect of hormone replacement therapy, tibolone and raloxifene on serum lipids, apolipoprotein A1, apolipoprotein B and lipoprotein(a) in Greek postmenopausal women

The aim of this study was to assess the effect of estrogen, two regimens of continuous combined hormone replacement therapy (HRT), tibolone and raloxffene on serum lipid, apolipoprotein A1 and B and lipoprotein(a) levels in Greek postmenopausal women. A total of 350 postmenopausal women were studied in a prospective open design. Women were assigned to one of the following regimens depending on the presence of risk factors for osteoporosis, dimacteric symptoms and an intact uterus: conjugated equine estrogen 0.625 mg (CEE, n = 34), continuous combined CEE 0.625 mg plus medroxyprogesterone acetate (MPA) 5 mg, (n = 80), continuous combined 17beta-estradiol 2 mg plus norethisterone acetate (NETA) 1 mg (n = 58), tibolone 2.5 mg (n = 83) and raloxifene HCl 60 mg (n = 50). Forty-five postmenopausal women with no indications for HRT served as controls. Total cholesterol (TC), low-density lipoprotein (LDL) cholestrol and high-density lipoprotein (HDL) cholesterol, triglyceride (TG), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and lipoprotein(a) (Lp(a)) levels were assessed in each subject at baseline, and at 6 and 12 months of therapy. All therapy regimens lowered TC levels compared to baseline (4.2-8.0% decrease). This effect was more prominent in the subgoup of women with high baseline TC levels (9.1-20.4% decrease). LDL cholesterol decreased significantly in CEE, CEE/MPA and raloxifene groups (-11.2%, -11.9% and -11.0%, respectively). Hypercholesterolemic women exhibited a steeper decrease in LDL cholesterol (10.6-27.8% in all therapy groups). TG levels increased significantly in the CEE and CEE/MPA groups (23.7% and 21.8%, respectively), while estradiol/NETA had no effect on TG levels. Tibolone decreased TG levels markedly, by 20.6%, while raloxifene had no TG-lowering effect. HDL cholesterol and ApoA1 were increased by CEE and CEE/MPA (HDL cholesterol, 7.4% and 11.8%, respectively; ApoA1, 17.8% and 7.9%, respectively) and decreased by tibolone (HDL cholesterol, -13.6%; and ApoA1, -9.9%). All therapy regimens except raloxifene lowered Lp(a) levels, with tibolone having the more pronounced effect (-13.2 to -29.0%). In conclusion, each therapy regimen had a diferent effect on lipid-lipoprotein levels, exerting favorable and unfavorable modifications. Hypercholesterolemic women seemed to benefit more from the cholesterol-lowering effect of estrogen replacement therapy/HRT. The choice for a particular regimen should be based on individual needs, indications and lipid-lipoprotein profile.

Estrogen, inflammation and cardiovascular risk in women: a critical appraisal

The widely shared enthusiasm about the cardioprotective potential of estrogenic compounds has come to an abrupt halt since randomized trials failed to show a cardiovascular risk reduction in postmenopausal women. This was unexpected because observational studies had strongly suggested that hormone replacement therapy would reduce the incidence of cardiovascular disease. Inflammatory activity is considered central in atherogenesis and atherosclerosis progression. Thus, parts of the striking discrepancy between observational and randomized data have been attributed to an estrogen-mediated adverse effect on inflammation. Here, we review the current clinical evidence with respect to the inflammation-modulating effects of different estrogenic compounds as one potential explanatory factor for these divergent findings. We conclude that it is still unclear whether estrogen-modulated inflammation is an important biological factor determining clinical outcome or a mere epiphenomenon.

Metabolic, inflammatory and haemostatic effects of a low-dose continuous combined HRT in women with type 2 diabetes: potentially safer with respect to vascular risk?

BACKGROUND

Conventional hormone replacement therapy (HRT) containing conjugated equine oestrogen (CEE) and medroxyprogesterone acetate (MPA) increases triglyceride, C-reactive protein (CRP) and coagulation Factor VII concentrations, potentially explaining their increased coronary heart disease (CHD) and stroke risk.

OBJECTIVE

To assess the metabolic effects of a continuous combined HRT containing 1 mg oestradiol and 0.5 mg norethisterone or matching placebo.

DESIGN

Double-blind, randomized placebo-controlled trial.

PATIENTS

Fifty women with type 2 diabetes.

MEASUREMENTS

Classical and novel risk factors for vascular disease.

RESULTS

Triglyceride concentration was not altered (P = 0.31, change in active arm relative to placebo) and low-density lipoprotein (LDL) cholesterol concentration declined 13% (P = 0.018). IL-6 concentration (mean difference -1.42 pg/ml, 95% CI: -2-55 to -0-29 IU/dl, P = 0.015), Factor VII (-32 IU/dl, -43 to -21 IU/l, P < 0.001) and tissue plasminogen activator antigen (by 13%, P = 0.005) concentrations fell, but CRP was not significantly altered (P = 0.62). Fasting glucose (P = 0.026) also declined significantly, but there are no significant effects on HBA1c, Factor IX or APC resistance.

CONCLUSIONS

HRT containing 1 mg oestradiol and 0.5 mg norethisterone may avoid the adverse metabolic effects potentially implicated in the elevated CHD and stroke risk induced by conventional higher dose HRT. This type of preparation may therefore be more suitable than conventional HRT for women at elevated CHD risk such as those with type 2 diabetes. Large randomized controlled trials of such low dose preparations, powered for cardiovascular end points, are now needed.

17 Beta-estradiol attenuates development of angiotensin II-induced aortic abdominal aneurysm in apolipoprotein E-deficient mice

OBJECTIVE

Angiotensin II (Ang II) promotes vascular inflammation, accelerates atherosclerosis, and induces abdominal aortic aneurysm (AAA). These changes were associated with activation of nuclear factor (NF)-kappaB-mediated induction of proinflammatory genes. The incidence of AAA in this model was higher in male than in female mice, and the vascular effects of estrogen may be associated with anti-inflammatory actions. The present study was undertaken to test the hypothesis that estrogen can attenuate Ang II-induced AAA in apolipoprotein E-deficient mice via its anti-inflammatory mechanism.

METHODS AND RESULTS

Infusion of Ang II (1.44 mg/kg per d for 1 month) induced AAA in 90% of the animals (n=20) with an expansion of the suprarenal aorta (diameter 1.9+/-0.14 mm versus <1 mm in normal mice). In mice treated with 17beta-estradiol (E2, 0.25-mg subcutaneous pellets), Ang II induced AAA only in 42% of the animals (n=19) with a significant reduction of average diameters of the suprarenal aorta (1.5+/-0.14 mm). E2 also decreased the expressions of intracellular adhesion molecule-1, vascular cellular adhesion molecule-1, E-selectin, monocyte chemotactic protein-1, and macrophage-colony stimulating factor in the aorta.

CONCLUSIONS

These data suggest that attenuation of AAA by E2 is associated with inhibition of proinflammatory gene expression.

Increased levels of C-reactive protein after oral hormone replacement therapy may not be related to an increased inflammatory response

BACKGROUND

It has been suggested that hormone replacement therapy (HRT) in postmenopausal women is associated with an increased inflammatory response that may trigger acute cardiovascular events. This suggestion is mainly based on the finding of elevated C-reactive protein (CRP) levels after HRT. The aim of the present study was to evaluate a broad spectrum of vascular inflammation markers in 389 postmenopausal women with increased cardiovascular risk at baseline and after either 6 months of HRT (126 women) or no HRT (263 women).

METHODS AND RESULTS

Compared with baseline, CRP levels significantly increased after HRT (0.9+/-0.2 versus 1.6+/-0.4 mg/L, P<0.01); on the contrary, soluble intracellular adhesion molecule-1 decreased from 208+/-57 to 168+/-37 ng/mL (P<0.01) after HRT. Similarly, vascular cell adhesion molecule-1 decreased from 298+/-73 to 258+/-47 ng/mL (P<0.01), plasma E-selectin levels were reduced from 17.8+/-5.6 to 14.8+/-3.9 ng/mL (P<0.01), interleukin-6 levels decreased from 1.51+/-0.22 to 1.29+/-0.28 pg/mL, and s-thrombomodulin plasma levels decreased from 4.8+/-0.7 to 4.3+/-0.9 ng/mL (P<0.01). No significant changes in either CRP or vascular inflammatory marker were detected in women not taking HRT.

CONCLUSIONS

The discrepancy between increased plasma levels of CRP and reduced plasma levels of all other markers of inflammation suggests that the increased CRP levels after oral HRT may be related to metabolic hepatic activation and not to an acute-phase response. HRT seems to be associated with an overall decrease in vascular inflammation.

Raloxifene, conjugated oestrogen and endothelial function in postmenopausal women

OBJECTIVES

To study the long-term effects of raloxifene, a potential designer oestrogen, and oestrogen monotherapy on endothelial function in healthy postmenopausal women.

DESIGN

A 2-year double-blind, randomized and placebo-controlled study in an Academic Medical Center. Fifty-six hysterectomized but otherwise healthy postmenopausal women randomly received raloxifene hydrochloride 60 mg day-1 (n = 15) or 150 mg day-1 (n = 13), conjugated equine oestrogen (CEE) 0.625 mg day-1 (n = 15), or placebo (n = 13).

MAIN OUTCOME MEASURES

Endothelial function as estimated from brachial artery flow-mediated, endothelium-dependent vasodilation and nitroglycerine-induced endothelium-independent vasodilation, and plasma levels of the endothelium-derived regulatory proteins, von Willebrand factor (vWF) and endothelin (ET).

RESULTS

Raloxifene 60 mg did not significantly affect endothelial function. As compared with placebo, at 6 months of therapy, raloxifene 150 mg and CEE were associated with a mean increase in vWF of 25.5% point (95% CI 3.6-47.3) and 26.6% point (95% CI 6.9-46.3), respectively. At 24 months of therapy, raloxifene 150 mg was associated with a mean decrease in ET of 0.96 pg mL-1 (95% CI -1.57 to -0.36). Raloxifene nor CEE significantly affected endothelium-dependent and/or -independent vasodilation.

CONCLUSIONS

Our results suggest that long-term therapy with raloxifene or oral CEE does not affect endothelium-dependent vasodilation in healthy postmenopausal women. Raloxifene 150 mg day-1 might have both positive and negative effects on endothelium. The clinical significance of these findings remains to be investigated.

Does the beneficial effect of HRT on endothelial function depend on lipid changes

OBJECTIVES

To determine whether improvement in endothelial function of the brachial artery observed in women treated with hormone replacement therapy (HRT) may be explained by changes in lipid profile or blood pressure, information was used obtained in a single-centre, randomised, double blind, placebo-controlled trial.

METHODS

Hundred-and-five healthy postmenopausal women, aged 50-65 years, were treated with 0.625 mg conjugated equine estrogens (CEE) combined with 2.5 mg medroxyprogesterone acetate (MPA) (CEE+MPA), 2.5 mg tibolone or placebo for 3 months. At baseline and after 3 months, endothelial function was assessed using flow-mediated dilatation (FMD) and nitro glycerine-mediated dilatation (NMD). Furthermore, lipids were measured. Multivariate linear regression analysis was applied to address the research question.

RESULTS

Treatment with CEE+MPA resulted in an improvement in FMD of 2.0% (95% CI: -0.1; 4.1). CEE/MPA reduced total cholesterol with 13% (95% CI: -18%; -7%), LDL-cholesterol with 23% (95% CI: -30%; -15%) and lipoprotein(a) (Lp(a)) with 14% (95% CI: -26%; -2%). The magnitude of the relation of CEE/MPA with endothelial function was attenuated to from 2.0 to 1.6% when change in Lp(a) was taken into account. Adjustments for other lipids or blood pressure did not attenuate the association.

CONCLUSIONS

The improvement in endothelial function in postmenopausal women treated with CEE+MPA appears to be partially mediated by change in Lp(a), and apparently not by changes in other lipids.

Effects of tibolone on cell adhesion molecules in postmenopausal women

OBJECTIVE

The first step in atherosclerosis is characterized by the adherence of lymphocytes and monocytes to cell adhesion molecules expressed by endothelial cells. Therefore, we wanted to investigate the effect of tibolone on the circulating levels of various cell adhesion molecules.

DESIGN

Thirty postmenopausal women were enrolled in a double-blind, randomized, placebo-controlled outpatient trial.

RESULTS

Tibolone led to a significant decrease in soluble intercellular adhesion molecule-1, soluble intercellular adhesion molecule-3, and soluble vascular cell adhesion molecule-1, but had no effect on monocyte chemotactic protein-1.

CONCLUSIONS

The direct favorable effects of tibolone on endothelial cells may explain the clinical benefits of this substance in terms of anti-ischemic effects and osteoporosis prevention.

Endothelin-1 and nitric oxide levels are related to cardiovascular risk factors but are not modified by estradiol replacement in healthy postmenopausal women. A cross-sectional and a randomized cross-over study

OBJECTIVE

To evaluate whether in healthy postmenopausal women endothelial substances such as endothelin-1 (ET-1) and nitric oxide are related to cardiovascular risk factors and can be influenced by estradiol replacement.

DESIGN

A cross-sectional evaluation and a randomized, double-blind, placebo-controlled study with cross-over.

METHODS

In 20 healthy postmenopausal women it was investigated the relation of ET-1 and NOx with age, BMI, 24-h blood pressure, lipid and glucose metabolism, and coagulation parameters. In addition, in the same women, the role played by estrogens on circulating ET-1 and stable derivatives of nitric oxide (nitrite/nitrates) was investigated by administering for 2 months transdermal estradiol (50 microg/day) vs. placebo.

RESULTS

ET-1 and NOx were inversely related to each other (r=0.458; P=0.016). Multivariate analysis of regression showed that ET-1 levels were related directly to LDL-cholesterol (r=0.585; P=0.0005) and protein C (r=0.516; P=0.0008), and inversely to insulin (r=0.488; P=0.0065). The ratio NOx/ET-1 was directly related to HDL-cholesterol (r=0.441; P=0.005). The above relations were not influenced by estradiol. Indeed, in comparison to placebo, transdermal estradiol, besides reducing nocturnal systolic (P=0.002) and diastolic (P=0.03) blood pressure, did not modify ET-1 or NOx levels, as well as, any of the parameters considered.

CONCLUSIONS

The relation of several cardiovascular risk factors with ET-1 and NOx/ET-1 suggests a primary role for these endothelial products in the determination of the cardiovascular risk of women. The present data do not support a role for transdermal estradiol in modifying ET-1 or NOx levels of healthy postmenopausal women.

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.

The effect of 17beta-estradiol on endothelial and inflammatory markers in postmenopausal women: a randomized, controlled trial

BACKGROUND

Intervention trials in postmenopausal women with coronary artery disease have failed to demonstrate beneficial effects of hormone replacement therapy (HRT) on the course of disease, potentially due to pro-inflammatory effects of conjugated equine estrogens. We characterized the effects of 48 weeks treatment with two estradiol-based HRT regimens on nonspecific (high sensitivity C-reactive protein [hs-CRP], blood sedimentation rate [BSR], fibrinogen) and specific endothelial markers (cell adhesion molecules: ICAM-1, VCAM-1, E-selectin).

METHOD AND RESULTS

Postmenopausal women randomly received either 1 mg 17beta-estradiol daily plus 25 microg gestodene for the last 12 days of each 28 day cycle (=standard dose progestin; n=65), or gestodene added each third cycle only (=low dose progestin; n=65), or no HRT (n=73). Both HRT regimens reduced levels of ICAM-1 (-9%), VCAM-1 (-9%), E-selectin (-11%), fibrinogen (-12%), BSR (-5%). No effect was observed on hs-CRP levels in any group. In smokers, E-selectin remained unchanged whereas ICAM-1 and VCAM-1 were lowered. Subjects on antihypertensive or lipid lowering medication showed effects comparable to the whole cohort. Effects of low and standard dose progestin were not different.

CONCLUSION

We conclude that a combination therapy with 1 mg 17beta-estradiol favourably affects the vascular inflammation processes as indicated by a neutral effect on hs-CRP and reduction of cell adhesion molecules.