Effect of hormone replacement therapy on age-related increase in carotid artery intima-media thickness in postmenopausal women

Menopausal Hormone Therapy and Subclinical Cardiovascular Disease in Women With and Without Human Immunodeficiency Virus

BACKGROUND

Estrogen-based hormone therapy (HT) may have beneficial cardiovascular effects when initiated in early menopause. This has not been examined in women with human immunodeficiency virus (HIV), who have heightened immune activation and cardiovascular risks.

METHODS

Among 609 postmenopausal women (1234 person-visits) in the Women's Interagency HIV Study, we examined the relationship of ever HT use (oral, patch, or vaginal) with subclinical atherosclerosis: carotid artery intima-media thickness (CIMT), distensibility, and plaque assessed via repeated B-mode ultrasound imaging (2004-2013). We also examined associations of HT with cross-sectional biomarkers of immune activation and D-dimer. Statistical models were adjusted for sociodemographic, behavioral, and cardiometabolic factors.

RESULTS

Women (mean age, 51 years; 80% HIV positive) who ever used HT at baseline were older, and more likely to be non-Hispanic White and report higher income, than never-users. Women who ever used HT had 43% lower prevalence of plaque (prevalence ratio, 0.57 [95% confidence interval {CI}, .40-.80]; P < .01), 2.51 µm less progression of CIMT per year (95% CI, -4.60, to -.41; P = .02), and marginally lower incidence of plaque over approximately 7 years (risk ratio, 0.38 [95% CI, .14-1.03; P = .06), compared with never-users, adjusting for covariates; ever HT use was not associated with distensibility. These findings were similar for women with and without HIV. Ever HT use was associated with lower serum D-dimer, but not with biomarkers of immune activation after covariate adjustment.

CONCLUSIONS

HT may confer a subclinical cardiovascular benefit in women with HIV. These results begin to fill a knowledge gap in menopausal care for women with HIV, in whom uptake of HT is very low.

Menopause Transition and Cardiovascular Disease Risk: Implications for Timing of Early Prevention: A Scientific Statement From the American Heart Association

Cardiovascular disease (CVD) is the leading cause of death in women, who have a notable increase in the risk for this disease after menopause and typically develop coronary heart disease several years later than men. This observation led to the hypothesis that the menopause transition (MT) contributes to the increase in coronary heart disease risk. Over the past 20 years, longitudinal studies of women traversing menopause have contributed significantly to our understanding of the relationship between the MT and CVD risk. By following women over this period, researchers have been able to disentangle chronological and ovarian aging with respect to CVD risk. These studies have documented distinct patterns of sex hormone changes, as well as adverse alterations in body composition, lipids and lipoproteins, and measures of vascular health over the MT, which can increase a woman's risk of developing CVD postmenopausally. The reported findings underline the significance of the MT as a time of accelerating CVD risk, thereby emphasizing the importance of monitoring women's health during midlife, a critical window for implementing early intervention strategies to reduce CVD risk. Notably, the 2011 American Heart Association guidelines for CVD prevention in women (the latest sex-specific guidelines to date) did not include information now available about the contribution of the MT to increased CVD in women. Therefore, there is a crucial need to discuss the contemporary literature on menopause and CVD risk with the intent of increasing awareness of the significant adverse cardiometabolic health-related changes accompanying midlife and the MT. This scientific statement provides an up-to-date synthesis of the existing data on the MT and how it relates to CVD.

Back to the future: Hormone replacement therapy as part of a prevention strategy for women at the onset of menopause

In the late 1980s, several observational studies and meta-analyses suggested that hormone replacement therapy (HRT) was beneficial for prevention of osteoporosis, coronary heart disease, dementia and decreased all-cause mortality. In 1992, the American College of Physicians recommended HRT for prevention of coronary disease. In the late 1990s and early 2000s, several randomized trials in older women suggested coronary harm and that the risks, including breast cancer, outweighed any benefit. HRT stopped being prescribed at that time, even for women who had severe symptoms of menopause. Subsequently, reanalyzes of the randomized trial data, using age stratification, as well as newer studies, and meta-analyses have been consistent in showing that younger women, 50-59 years or within 10 years of menopause, have decreased coronary disease and all-cause mortality; and did not have the perceived risks including breast cancer. These newer findings are consistent with the older observational data. It has also been reported that many women who abruptly stopped HRT had more risks, including more osteoporotic fractures. The current data confirm a "timing" hypothesis for benefits and risks of HRT, showing that younger have many benefits and few risks, particularly if therapy is predominantly focused on the estrogen component. We discuss these findings and put into perspective the potential risks of treatment, and suggest that we may have come full circle regarding the use of HRT. In so doing we propose that HRT should be considered as part of a general prevention strategy for women at the onset of menopause.

Intima-media thickness: indicator of cardiovascular risk and measure of the extent of atherosclerosis

The measurement of intima-media thickness (IMT) of large superficial arteries, especially the carotid, using high-resolution B-mode ultrasonography has emerged as one of the methods of choice for determining the anatomic extent of atherosclerosis and for assessing cardiovascular risk. IMT measurement obtained by ultrasonography correlates very well with pathohistologic measurements and the reproducibility of this technique is good. Population studies have shown a strong correlation between carotid IMT and several cardiovascular risk factors, and it has also been found to be associated with the extent of atherosclerosis and end-organ damage of high-risk patients. Therefore, increased carotid IMT is a measure of athero-sclerotic burden and a predictor of subsequent events. Because of its quantitative value, carotid IMT measurement is more and more frequently used in clinical trials to test the effects of different preventive measures, including drugs. More recently, there has been interest in the clinical use of this technique for detecting preclinical (asymptomatic) atherosclerosis and for identifying subjects at high risk. Measurement of carotid IMT could influence a clinician to intervene with medication and to use more aggressive treatment of risk factors in primary prevention, and in patients with atherosclerotic disease in whom there is evidence of progression and extension of atherosclerotic disease. For more extensive use of this method in clinical practice a consensus concerning the standardization of methods of measurement and precise definition of threshold between normal and pathologic IMT value is urgently needed.

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.

Vascular Aging across the Menopause Transition in Healthy Women

Vascular aging, featuring endothelial dysfunction and large artery stiffening, is a major risk factor for developing cardiovascular disease (CVD). In women, vascular aging appears to be accelerated during the menopause transition, particularly around the late perimenopausal period, presumably related to declines in ovarian function and estrogen levels. The mechanisms underlying endothelial dysfunction and large artery stiffening with the menopause transition are not completely understood. Oxidative stress and the proinflammatory cytokine tumor necrosis factor-α contribute to endothelial dysfunction and large artery stiffening in estrogen-deficient postmenopausal women. Habitual endurance exercise attenuates the age-related increase in large artery stiffness in estrogen-deficient postmenopausal women and can reverse arterial stiffening to premenopausal levels in estrogen-replete postmenopausal women. In contrast, estrogen status appears to play a key permissive role in the adaptive response of the endothelium to habitual endurance exercise in that endothelial improvements are absent in estrogen-deficient women but present in estrogen-replete women. We review here the current state of knowledge on the biological defects underlying vascular aging across the menopause transition, with particular focus on potential mechanisms, the role of habitual exercise in preserving vascular health, and key areas for future research.

Synthetic gestagens exert differential effects on arterial thrombosis and aortic gene expression in ovariectomized apolipoprotein E-deficient mice

BACKGROUND AND PURPOSE

Combined hormone replacement therapy with oestrogens plus the synthetic progestin medroxyprogesterone acetate (MPA) is associated with an increased risk of thrombosis. However, the mechanisms of this pro-thrombotic effect are largely unknown. The purpose of this study was to: (i) compare the pro-thrombotic effect of MPA with another synthetic progestin, norethisterone acetate (NET-A), (ii) determine if MPA's pro-thrombotic effect can be antagonized by the progesterone and glucocorticoid receptor antagonist mifepristone and (iii) elucidate underlying mechanisms by comparing aortic gene expression after chronic MPA with that after NET-A treatment.

EXPERIMENTAL APPROACH

Female apolipoprotein E-deficient mice were ovariectomized and treated with placebo, MPA, a combination of MPA + mifepristone or NET-A for 90 days on a Western-type diet. Arterial thrombosis was measured in vivo in a photothrombosis model. Aortic gene expression was analysed using microarrays; GeneOntology and KEGG pathway analyses were conducted.

KEY RESULTS

MPA's pro-thrombotic effects were prevented by mifepristone, while NET-A did not affect arterial thrombosis. Aortic gene expression analysis showed, for the first time, that gestagens induce similar effects on a set of genes potentially promoting thrombosis. However, in NET-A-treated mice other genes with potentially anti-thrombotic effects were also affected, which might counterbalance the effects of the pro-thrombotic genes.

CONCLUSIONS AND IMPLICATIONS

The pro-thrombotic effects of synthetic progestins appear to be compound-specific, rather than representing a class effect of gestagens. Furthermore, the different thrombotic responses elicited by MPA and NET-A might be attributed to a more balanced, 'homeostatic' gene expression induced in NET-A- as compared with MPA-treated mice.

Common carotid artery diameter and cardiovascular risk factors in overweight or obese postmenopausal women

Arterial diameter is an underutilized indicator of vascular health. We hypothesized that interadventitial and lumen diameter of the common carotid artery would be better indicators of vascular health than carotid plaque or intima media thickness (IMT). Participants were 491 overweight or obese, postmenopausal women who were former or current hormone therapy (HT) users, 52-62 years, with waist circumference >80 cm. We evaluated cross-sectional associations of cardiovascular risk factors with carotid measures, by HT status. Former HT users had a worse cardiovascular profile than current HT users: larger adventitial (6.94 mm versus 6.79 mm) and lumen diameter (5.44 mm versus 5.31 mm, both P < 0.01) independent of cardiovascular risk factors; IMT and plaque were similar. Larger diameters were best explained by former HT use, higher pulse pressure, and greater weight. Independent of potential confounders, overweight and obese postmenopausal former HT users had larger carotid diameters than current HT users. Carotid diameter should be considered in studies of HT.

The 2012 hormone therapy position statement of: The North American Menopause Society

OBJECTIVE

This position statement aimed to update the evidence-based position statement published by The North American Menopause Society (NAMS) in 2010 regarding recommendations for hormone therapy (HT) for postmenopausal women. This updated position statement further distinguishes the emerging differences in the therapeutic benefit-risk ratio between estrogen therapy (ET) and combined estrogen-progestogen therapy (EPT) at various ages and time intervals since menopause onset.

METHODS

An Advisory Panel of expert clinicians and researchers in the field of women's health was enlisted to review the 2010 NAMS position statement, evaluate new evidence, and reach consensus on recommendations. The Panel's recommendations were reviewed and approved by the NAMS Board of Trustees as an official NAMS position statement.

RESULTS

Current evidence supports the use of HT for perimenopausal and postmenopausal women when the balance of potential benefits and risks is favorable for the individual woman. This position statement reviews the effects of ET and EPT on many aspects of women's health and recognizes the greater safety profile associated with ET.

CONCLUSIONS

Recent data support the initiation of HT around the time of menopause to treat menopause-related symptoms and to prevent osteoporosis in women at high risk of fracture. The more favorable benefit-risk ratio for ET allows more flexibility in extending the duration of use compared with EPT, where the earlier appearance of increased breast cancer risk precludes a recommendation for use beyond 3 to 5 years.

Association of menopause and hormone replacement therapy with large artery remodeling

OBJECTIVE

To evaluate the remodeling of large arteries according to age at menopause, duration of menopause, and use of hormone therapy (HT).

DESIGN

A cross-sectional study consisting of baseline measurements of a multicentric randomized trial were used to evaluate arterial parameters.

SETTING

The study was conducted in France, Belgium, and the Netherlands in academic hospitals and private clinics.

PATIENT(S)

Postmenopausal women (n = 538) with mild hypercholesterolemia.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Common carotid artery intima-media thickness (CCA-IMT), central pulse pressure, and aortic stiffness (carotid-femoral pulse wave velocity) were measured and centrally controlled for quality. Multivariate regression analysis was used to assess the possible covariates associated with arterial parameters.

RESULT(S)

Women were 58 ± 6 (mean ± SD) years of age with an age of 50 ± 5 at menopause and a mean duration of menopause of 8 ± 7 years. Lower age at menopause, time since menopause, and absence of HT use were independently associated with worsening of the arterial parameters. After multivariate analysis, HT was associated with a lower CCA-IMT (-40 μm [range -64 to -1]), whereas lower age at menopause and menopause duration were respectively associated with a CCA-IMT increase (25 μm/5 y and 27 μm/5 y). Similarly, values of central pulse pressure and pulse wave velocity were lower in HT users (-3.1 mm Hg [-5.1 to -0.9] and -0.31 m/s [-0.63 to -0.02], respectively) but worsened with age at menopause and menopause duration.

CONCLUSION(S)

The age at menopause, the time since menopause, and the use of HT are independently associated with the thickening and stiffening of the large arteries.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00163163.

Post menopausal hormones and measures of subclinical atherosclerosis: the multi-ethnic study of atherosclerosis

OBJECTIVE

To evaluate whether post menopausal hormones are associated with atherosclerosis.

METHODS

We studied the relation of hormone use to coronary calcification and carotid intima-media thickness in a cross-sectional sample of 3245 post menopausal women, of whom 1620 had used hormones for various periods. Adjusted associations with three measures of hormone use (ever use, duration, and type of hormone) were estimated by multivariable regression.

RESULTS

The prevalence of coronary calcification was only 4 percentage points lower in women who had ever used hormones than in women who had not (40% versus 44%), and was not monotonically related to longer use: <2 years: 38%; 2-6 years: 36%; 6-13 years: 41%; >13 years: 48%. Similarly, duration of hormone use did not show a monotonic dose-response relation with the calcium score. Mean differences in carotid intima-media thickness according to categories of years of hormone use and type of hormone ranged from -0.10 mm to +0.08 mm, with no consistent patterns. Most adjusted associations were weak and sometimes contrary to our expectation.

CONCLUSIONS

We did not find meaningful associations between hormone use and subclinical atherosclerosis-neither to support benefit or harm, nor to support the prevailing theory of "healthy user" bias (namely, inverse associations due to residual confounding).

High-sensitivity C-reactive protein is independently associated with early carotid artery progression in women but not in men: the INVADE Study

BACKGROUND AND PURPOSE

High-sensitivity C-reactive protein (hsCRP) is known to be associated with atherosclerosis and cardiovascular events. Limited information exists regarding the importance of sex differences for the association between hsCRP and the progression of early stages of atherosclerosis. Therefore, we investigated the effect of hsCRP on early carotid atherosclerosis progression and major vascular risk factors in men and women.

METHODS

We analyzed the data of INVADE (intervention project on cerebrovascular diseases and dementia in the community of Ebersberg, Bavaria), a prospective, population-based study. In addition to common risk factors, measurements of carotid intima-media-thickness and hsCRP were performed at baseline and after 2 years.

RESULTS

Complete baseline data were available for 3387 subjects including 2001 women, and complete follow-up data were available for 2346 subjects. Within this study population, women were older and had higher systolic blood pressure and cholesterol levels. The prevalence of smoking and ischemic heart disease was more frequent in men. The baseline carotid intima-media-thickness was significantly higher in men compared with women (0.82 mm; 95% CI, 0.812 to 0.834 mm versus 0.77 mm; 95% CI, 0.763 to 0.779 mm; P<0.0001). Carotid intima-media-thickness progression after risk factor adjustment was significantly associated with hsCRP in women (P=0.006) but not in men (P=0.39).

CONCLUSIONS

The association between hsCRP and progression of early carotid atherosclerosis shows sex differences. In further studies analyzing the role of inflammation for cardiovascular diseases and atherosclerosis, these sex differences should be considered.

Thicker carotid intima layer and thinner media layer in subjects with cardiovascular diseases. An investigation using noninvasive high-frequency ultrasound

BACKGROUND

The thickness of the arterial intima increases and that of the media decreases with increasing age and degree of atherosclerosis. Separate estimates of the individual intima and media layers might therefore be more appropriate than the commonly used method estimating the combined intima-media thickness (IMT).

METHODS AND RESULTS

One hundred consecutive 70-year-old subjects from the PIVUS study were investigated. Separate estimates of the thickness of the carotid artery intima and media wall layers were carried out noninvasively using 25MHz high-frequency ultrasound. Subjects with a diagnosis of cardiovascular disease (CVD), coronary heart disease (CHD), myocardial infarction (MI) or stroke had a significantly thicker intima layer (all P<0.0001) and a thinner media layer (all P<0.05) than healthy subjects. The intima/media thickness ratio also differed significantly between subjects with and without a diagnosis of CVD (0.43+/-0.20versus 0.75+/-0.48, P=0.0002). Subjects with hypertension or hyperlipidemia also had a thicker carotid intima than subjects without these diagnoses (P<0.0005 for both). None of the corresponding intima+media thickness values differed significantly. Similar results were obtained in women and men.

CONCLUSION

Separate assessment of carotid artery intima and media thickness using noninvasive high-frequency ultrasound appears to be of potential value, as a striking difference in intima thickness and the intima/media thickness ratio was found between subjects with and without CVD.

Osteoporosis in otherwise healthy perimenopausal and early postmenopausal women: physical and biochemical characteristics

Population studies have shown that about 3-5% of perimenopausal women already have osteoporosis according to the WHO definition of osteoporosis for postmenopausal women ( t -score<or=-2.5). In general, this bone loss arises from well-characterized diseases or conditions that affect acquisition of peak bone mass and/or the rate of bone loss after peak bone mass has been attained. However, there often remains a subset of these women, with no identifiable cause of bone loss. This group has so far been little studied. We prospectively evaluated a group of 60 perimenopausal and early postmenopausal women (mean age 52.2+/-2.5 years) who were found to have apparently unexplained low bone mass, and we compared them to 120 controls matched for age and menopausal status. These women were extensively investigated, including by detailed questionnaire and laboratory testing. Of the 60 women with osteoporosis, only three were found to have previously undiagnosed disorders (two with subclinical hyperthyroidism and one with elevated serum PTH levels) that might have contributed to their low bone mass. On the other hand, osteoporotic patients were characterized by a significantly lower body weight, higher prevalence of personal and parental histories of fractures and a higher level of bone turnover as assessed by increased serum osteocalcin and bone alkaline phosphatase levels and urinary type I collagen C-telopeptide (CTX) excretion, as compared to controls. These findings support theories of a genetic contribution to osteoporosis and underline the predictive value of a previous history of personal and familial fracture in the identification of osteoporosis in early postmenopausal women.

Effects of Combined Estriol/Pravastatin Therapy on Intima-Media Thickness of Common Carotid Artery in Hyperlipidemic Postmenopausal Women

BACKGROUND

Several studies show that 17beta-estradiol (E2) has protective effects on atherosclerosis in the arterial wall in postmenopausal women. Little information is, however, available regarding the effect of estriol (E3) on atherosclerosis. This study was conducted to investigate the effects of E3 alone and combined E3/pravastatin therapy on intima-media thickness (IMT) of common carotid artery in postmenopausal women.

METHODS

Thirty-three postmenopausal women were allocated to four groups: daily treatment with E3 (2 mg) alone (E3 group, n = 10), pravastatin (10 mg) alone (pravastatin group, n = 6), combined treatment with E3 (2 mg) and pravastatin (10 mg; E3/pravastatin group, n = 7) and untreated control group (n = 10). All women attended the Kobe University Hospital once a year for routine gynecological and ultrasonographic examinations for the evaluation of atherosclerosis.

RESULTS

A significant decrease in IMT was noted in the E3/pravastatin group compared with that in the untreated control group (p < 0.05), whereas there was no significant difference in the reduction rate of IMT in the pravastatin group, E3 group and untreated control group.

CONCLUSIONS

The combined E3/pravastatin therapy appeared to retard the progression of atherosclerosis in postmenopausal women.

Effect of Transdermal Hormone Replacement Therapy on Carotid Artery Wall Thickness and Levels of Vascular Inflammatory Markers in Postmenopausal Women

Carotid intima-media thickness (IMT) and vascular inflammatory markers have been shown to be involved in atherosclerosis. This study was designed to investigate the effect of transdermal hormone replacement therapy (HRT) on carotid IMT and vascular inflammatory markers in postmenopausal women and to explore the interrelationship between the change in carotid IMT and the changes in vascular inflammatory markers. Thirty-five postmenopausal women (mean age 57.0+/-7.7 years) received transdermal HRT (continuous 17beta-estradiol patch [36 microg/day] plus cyclic oral medroxyprogesterone acetate [2.5 mg/day, for 12 days/ month]) for 12 months, and 32 controls (mean age 58.0+/-7.5 years) did not. Carotid IMT, assessed by ultrasound, and circulating vascular inflammatory markers, i.e., C-reactive protein (CRP), intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, E-selectin, monocyte chemoattractant protein (MCP)-1, and matrix metalloproteinase (MMP)-9 were measured before and after 12 months of treatment. In the HRT group, carotid IMT decreased significantly (p<0.01), from 0.71+/-0.13 mm to 0.65+/-0.12 mm, and the ICAM-1, VCAM-1, E-selectin, and MCP-1 levels decreased significantly (p<0.01 for all), but the CRP and MMP-9 levels remained unchanged. Carotid IMT and vascular inflammatory markers were unchanged in the control group. In the HRT group, the change in carotid IMT was significantly correlated with the change in serum E-selectin (r=0.38, p<0.05), but not with the changes in other vascular inflammatory markers. These results suggest that transdermal HRT reduced carotid artery wall thickness, and that the reduction may have been induced by an antiatherosclerotic effect combined with the direct effect of estrogen and decreased levels of estrogen-induced E-selectin.

Does hormone replacement therapy influence retinal microvascular caliber?

Previous population-based data suggest that retinal arteriolar diameter is wider in women than in men. Estrogen exposures could account for this difference. To evaluate the effects of HRT on small blood vessels, we assessed the relationship between use of hormone replacement therapy (HRT) and retinal microvascular diameter in older women in the Blue Mountains Eye Study baseline population (n = 1993, age >/= 49 years). Information on HRT use was recorded by trained interviewers. A computer-assisted program measured retinal vessel diameters from digitized photographs. Average arteriolar diameter was calculated as the central retinal arteriolar equivalent (CRAE); the lowest quintile of CRAE was considered generalized arteriolar narrowing. Of the 1897 women with complete data, 79 (4%) were premenopausal and 315 (17%), 224 (12%), and 1279 (67%) were current, past, and never HRT users, respectively. Among women aged < 65 years, multivariate-adjusted mean CRAE for the four groups was 196, 198, 201, and 200 microm (P < 0.0001), respectively. Among postmenopausal women >/= 65 years, multivariate-adjusted mean CRAE was 187, 188, 191 microm (P < 0.0001), respectively, for current, past, and never users. Current HRT users were 40% more likely than never users to have generalized arteriolar narrowing (95% confidence interval 1.0-2.1). It appears that the use of HRT in older women may not have any long-term vasodilatory effects on retinal arterioles. These data do not support our hypothesis that exogenous estrogen exposures account for observed wider retinal arteriolar diameters in women.

Comparative vascular effects of hormone replacement therapy and raloxifene in women at increased cardiovascular risk

Hormone replacement therapy (HRT) improves endothelial function in postmenopausal women while the effects of raloxifene, a selective estrogen receptor modulator, are still under debate. The aim of this study was to evaluate endothelium-dependent flow-mediated vasodilatation in the brachial artery and plasma levels of nitrite, nitrate and endothelin-1 in 20 postmenopausal women with increased cardiovascular risk treated with either HRT or raloxifene for 4 weeks in a randomized double-blind single cross-over study. Patients had an endothelium-dependent flow-mediated dilatation of 4% prior to initiation of the study. Treatment with HRT resulted in a 67% increase in dilatation compared with baseline (from a 7.4% increase to a 12.4% increase, p < 0.01). Raloxifene treatment resulted in no change in vasodilatation from baseline. Endothelium-dependent dilatation was significantly improved by HRT compared with raloxifene treatment (12.4+/-0.6% vs. 6.1+/-2.0%; p < 0.01). Compared with baseline values, nitrate plus nitrite levels increased significantly (p < 0.05) with HRT but not with raloxifene. Similarly, endothelin-1 decreased from baseline with both treatments, but only the HRT-induced decrease was statistically significant (p < 0.05). In conclusion, HRT improved endothelial function and reduced plasma levels of endothelin-1 in postmenopausal women at risk of coronary artery disease. These beneficial effects were not shared by raloxifene.

Association of cardiovascular risk factors with intima-media thickness of the carotid arteries in early postmenopausal women

OBJECTIVE

The aim of this study was to examine the association between carotid intima-media thickness (IMT) and coronary heart diseases (CHD) risk factors in a large population of peri- and postmenopausal women.

DESIGN

Participants in this study were 906 healthy peri- and postmenopausal women from southwestern France, 45 to 65 years old with no history of cardiovascular disease and no utilization of estrogen/hormone therapy. Women were classified either as perimenopausal (n = 240) or post-menopausal (n = 666) according both to the regularity of menses and to serum follicle-stimulating hormone and estradiol values. All women answered a questionnaire, which included 72 questions, related to the identification of familial and personal cardiovascular risk factors. Biological measurements were performed to evaluate their lipid-lipoprotein profiles and fasting glucose levels, ultrasonography was used to measure IMT and total body scanners by DXA were performed to determine the percentage of body fat.

RESULTS

Multiple regression analyses were used to examine the ability of each variable to explain IMT values. Mean IMT of the right carotid artery was 0.520 (+/- 0.07) mm. Of the 906 women, 9% were currently taking lipid-lowering drugs, 12.8% and less than 2% were being treated for hypertension and diabetes, respectively. Additionally, 124 women were found to have current hypertension, 10% had a familial history of CHD, and 18% were regular smokers. In multiple regression analyses, only increasing age (P < 0.001) and systolic and diastolic blood pressure (P < 0.001) were independently and significantly associated with IMT.

CONCLUSIONS

These results show that only a few risk factors were associated with IMT in this population of healthy peri- and postmenopausal women. These results might be related to the fact that this study was conducted in an area of France well known for having the lowest rates of CHD in women, which is further supported by the thinner IMT found in this population as compared with a higher-risk population. Therefore, these results might not be relevant for CHD in older or high-risk women.

[Impact of HRT on the arterial carotid vascular tree]

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

Effect of tibolone treatment on intima-media thickness and the resistive indices of the carotid arteries

OBJECTIVE

To assess the effect of tibolone treatment on the intima-media thickness (IMT) of the common carotid artery (CCA) and the resistive indices (RIs) of the CCA and internal (ICA) and external (ECA) carotid and the vertebral arteries (VAs) in postmenopausal women as sonographic markers of atherosclerosis.

DESIGN

A prospective study.

SETTING

University hospital.

PATIENT(S)

Twenty postmenopausal women who had no cardiovascular disease.

INTERVENTION(S)

Noninvasive measurements of the IMT of the CCA and the RI of the CCA, ICA, ECA, and VA were made with ultrasound at baseline and after 12 weeks of tibolone treatment.

MAIN OUTCOME MEASURE(S)

IMT of the CCA and RI of the CCA, ICA, ECA, and VA.

RESULT(S)

Three months of tibolone treatment decreased the IMT of the CCA (mean +/- SD) from 0.70 +/- 0.22 mm (95% confidence interval [CI], 0.60-0.80) to 0.47 +/- 0.17 mm (95% CI, 0.39-0.55) by 28%. Resistive indices of the CCA, ICA, and VA also decreased significantly.

CONCLUSION(S)

The present study showed that tibolone treatment decreases both the IMT of the CCA and RI of the CCA, ICA, and VA, which appears to be related to its anti-atherosclerotic effect. Nevertheless, the clinical implications of these findings are yet to be investigated.

Arterial intima-media thickness: site-specific associations with HRT and habitual exercise

We determined the site-specific relations of hormone replacement therapy (HRT) and habitual exercise status with intima-media thickness (IMT) in both elastic (carotid) and muscular (femoral) arteries in 77 healthy postmenopausal women: 43 women were sedentary (20 no-HRT and 23 HRT users) and 34 women were endurance trained (14 no-HRT and 20 HRT users). Femoral IMT was not different among the sedentary HRT and endurance-trained no-HRT and HRT groups, but was lower (P < 0.005) in these three groups than in the sedentary no-HRT women. There were no significant group differences in carotid IMT. However, in older women (> or =65 yrs) carotid IMT was smaller (P < 0.05) in HRT compared with no-HRT women. We conclude that both endurance training and HRT status are independently associated with a smaller IMT and these effects are evident primarily in muscular arteries. These results suggest that HRT and habitual exercise may protect postmenopausal women against cardiovascular disease through influences on IMT. The site-specific relations may be due to a greater number of smooth muscle cells and plasticity of muscular arteries compared with elastic arteries and/or differences in heterogeneous influences such as metabolic requirements and hydrostatic pressures.

Carotid intima-media thickness in surgical menopause: women who received HRT versus who did not

OBJECTIVE

The effects of hormone replacement therapy (HRT) in the natural menopausal period have been extensively studied. However, these effects have almost none been studied in purely surgical menopause. The aim of this study was to measure intima-media thickness (IMT) of carotid arteries bilaterally in two groups of surgical menopausal women who received HRT versus who did not.

METHODS

A B-mode ultrasound unit was used for the measurements of the IMTs of carotid arteries in two groups. Measurements of Group 1 (n=65, untreated group) were compared with those of Group 2 (n=70, treated group), in 2-years of follow-up. Patients in Group 2 received daily doses of 0.625 mg of oral conjugated estrogen preparates. Serum estradiol levels, lipid profiles, and blood pressures were measured, pre and postoperatively. For the statistical analyses in terms of differences of IMTs between two groups, general factorial analysis of variation was used.

RESULTS

Among preoperative values of low-density lipoprotein (LDL), high-density lipoprotein (HDL), cholesterol, systolic and diastolic blood pressures, estradiol, and age, only the estradiol values showed significant difference between both groups. The statistical results concerning the postoperative IMT differences for both groups showed that there was a statistically significant difference when comparing both groups, showing an increase in IMT in Group 1.

CONCLUSION

In surgical menopausal women, the direction of the HRT effect is in agreement with evidence from earlier studies on the effects of HRT in natural menopausal women.

Acute relaxant effects of 17-beta-estradiol through non-genomic mechanisms in rabbit carotid artery

Estrogens could play a cardiovascular protective role not only by means of systemic effects but also by means of direct effects on vascular structure and function. We have studied the acute effects and mechanisms of action of 17-beta-estradiol on vascular tone of rabbit isolated carotid artery. 17-Beta-estradiol (10, 30, and 100 microM) elicited concentration-dependent relaxation of 50 mM KCl-induced active tone in male and female rabbit carotid artery. The stereoisomer 17-alpha-estradiol showed lesser relaxant effects in male rabbits. Endothelium removal did not modify relaxation induced by 17-beta-estradiol. The NO synthase inhibitor L-NAME (100 microM) only reduced significantly relaxation produced by 30 microM 17-beta-estradiol. Relaxation was not modified by the estrogen receptor antagonist ICI 182,780 (1 microM), the protein synthesis inhibitor cycloheximide (1 microM), and the selective K(+) channel blockers charybdotoxin (0.1 microM) and glibenclamide (1 microM). CaCl(2) (30 microM -10 mM) induced concentration-dependent contraction in rabbit carotid artery depolarized by 50 mM KCl in Ca(2+) free medium. Preincubation with 17-beta-estradiol (3, 10, 30, or 100 microM) or the L-type Ca(2+) channel blocker nicardipine (0.01, 0.1, 1, or 10 nM) produced concentration-dependent inhibition of CaCl(2)-induced contraction. In conclusion, 17-beta-estradiol induces endothelium-independent relaxation of rabbit carotid artery, which is not mediated by classic estrogen receptor and protein synthesis activation. The relaxant effect is due to inhibition of extracellular Ca(2+) influx to vascular smooth muscle, but activation of K(+) efflux is not involved. Relatively high pharmacological concentrations of estrogen causing relaxation preclude acute vasoactive effects of plasma levels in the carotid circulation.

Association between carotid arterial remodeling and plasma concentration of circulating hepatocyte growth factor

BACKGROUND

Several studies have reported that the circulating concentration of hepatocyte growth factor (HGF) was increased in individuals with clinically overt atherosclerotic disease, including coronary heart disease and peripheral arterial disease. However, whether changes in the circulating concentration of HGF are associated with early atherosclerotic changes in apparently healthy individuals remains to be determined.

OBJECTIVE

To investigate the relationship between the plasma concentration of HGF and carotid arterial remodeling.

METHODS

Plasma concentrations of HGF were measured in 201 community-dwelling healthy residents free from any medications and signs and history of cardiovascular disease. Carotid intima-media thickness (IMT) and carotid internal diameter were determined by ultrasonography with a 7.5 MHz probe. The study participants were divided into four groups according to the presence or absence of carotid atherosclerosis (presence of plaque, IMT > or = 0.85 mm) and carotid arterial dilatation (diameter > or = 7.0 mm).

RESULTS

Carotid arterial remodeling, atherosclerosis or dilatation, or combinations thereof, was associated with significantly greater concentrations of plasma HGF. Among risk factors, plasma HGF was significantly associated with advanced age (> or = 65 years), current smoking and diabetes mellitus, whereas sex, obesity, hypertension and hypercholesterolemia did not affect plasma concentrations of HGF. Multiple regression analysis showed that plasma HGF was independently associated with carotid arterial remodeling (atherosclerosis, dilatation, or both) in addition to age and systolic blood pressure.

CONCLUSIONS

These results indicate that the plasma concentration of HGF increases in relation to carotid arterial remodeling, independently of known risk factors for atherosclerosis. These findings further support a possible role of HGF in atherosclerosis.