Effect of transdermal estradiol and oral conjugated estrogen on C-reactive protein in retinoid-placebo trial in healthy women

The longitudinal relation of inflammation to incidence of vasomotor symptoms

OBJECTIVE

Vasomotor symptoms (VMS), the most frequently reported symptoms during the menopausal transition, have been associated with inflammation. Whether inflammation is a risk factor for or a consequence of VMS remains unclear. The objectives of these analyses were to determine if elevated proinflammatory marker levels were associated with increased incident VMS in women without VMS at baseline and whether these associations varied by menopause transition stage or race/ethnicity.

METHODS

We used longitudinal data on incident VMS, high-sensitivity C-reactive protein (hs-CRP; n = 1,922) and interleukin-6 (IL-6; n = 203) from 13 follow-up visits in the Study of Women's Health Across the Nation, which included five racial/ethnic groups of midlife women. We performed multivariable discrete-time survival analyses to determine adjusted hazard ratios (aHRs) for the association of these proinflammatory markers with incident VMS in women without VMS at baseline.

RESULTS

We found no significant associations of incident VMS with dichotomized hs-CRP (>3 vs ≤3 mg/L) at baseline, concurrent or prior visit (aHRs, 1.04-2.03) or IL-6 (>1.44 vs ≤1.44 pg/mL) at visit 1, concurrent or prior visit (aHRs, 0.67-1.62), or continuous hs-CRP or IL-6 values over 13 follow-up visits (with nonsignificant adjusted increased hazards ranging from 0% to 2%).

CONCLUSIONS

Our results showed no significant association of the proinflammatory biomarkers, hs-CRP or IL-6, either concurrently or with subsequent incident VMS, indicating that inflammation was unlikely to be a risk factor for VMS. Thus, clinical treatments directed at reducing inflammation would be unlikely to reduce the occurrence of VMS.

Role of C-Reactive Protein at Sites of Inflammation and Infection

C-reactive protein (CRP) is an acute inflammatory protein that increases up to 1,000-fold at sites of infection or inflammation. CRP is produced as a homopentameric protein, termed native CRP (nCRP), which can irreversibly dissociate at sites of inflammation and infection into five separate monomers, termed monomeric CRP (mCRP). CRP is synthesized primarily in liver hepatocytes but also by smooth muscle cells, macrophages, endothelial cells, lymphocytes, and adipocytes. Evidence suggests that estrogen in the form of hormone replacement therapy influences CRP levels in the elderly. Having been traditionally utilized as a marker of infection and cardiovascular events, there is now growing evidence that CRP plays important roles in inflammatory processes and host responses to infection including the complement pathway, apoptosis, phagocytosis, nitric oxide (NO) release, and the production of cytokines, particularly interleukin-6 and tumor necrosis factor-α. Unlike more recent publications, the findings of early work on CRP can seem somewhat unclear and at times conflicting since it was often not specified which particular CRP isoform was measured or utilized in experiments and whether responses attributed to nCRP were in fact possibly due to dissociation into mCRP or lipopolysaccharide contamination. In addition, since antibodies for mCRP are not commercially available, few laboratories are able to conduct studies investigating the mCRP isoform. Despite these issues and the fact that most CRP research to date has focused on vascular disorders, there is mounting evidence that CRP isoforms have distinct biological properties, with nCRP often exhibiting more anti-inflammatory activities compared to mCRP. The nCRP isoform activates the classical complement pathway, induces phagocytosis, and promotes apoptosis. On the other hand, mCRP promotes the chemotaxis and recruitment of circulating leukocytes to areas of inflammation and can delay apoptosis. The nCRP and mCRP isoforms work in opposing directions to inhibit and induce NO production, respectively. In terms of pro-inflammatory cytokine production, mCRP increases interleukin-8 and monocyte chemoattractant protein-1 production, whereas nCRP has no detectable effect on their levels. Further studies are needed to expand on these emerging findings and to fully characterize the differential roles that each CRP isoform plays at sites of local inflammation and infection.

Associations of Steroid Sex Hormones and Sex Hormone-Binding Globulin With the Risk of Type 2 Diabetes in Women: A Population-Based Cohort Study and Meta-analysis

It remains unclear whether endogenous sex hormones (ESH) are associated with risk of type 2 diabetes (T2D) in women. Data of 3,117 postmenopausal women participants of the Rotterdam Study were analyzed to examine whether ESH and sex hormone-binding globulin (SHBG) were associated with the risk of incident T2D. Additionally, we performed a systematic review and meta-analysis of studies assessing the prospective association of ESH and SHBG with T2D in women. During a median follow-up of 11.1 years, we identified 384 incident cases of T2D in the Rotterdam Study. No association was observed between total testosterone (TT) or bioavailable testosterone (BT) with T2D. SHBG was inversely associated with the risk of T2D, whereas total estradiol (TE) was associated with increased risk of T2D. Similarly, in the meta-analysis of 13 population-based prospective studies involving more than 1,912 incident T2D cases, low levels of SHBG and high levels of TE were associated with increased risk of T2D, whereas no associations were found for other hormones. The association of SHBG with T2D did not change by menopause status, whereas the associations of ESH and T2D were based only in postmenopausal women. SHBG and TE are independent risk factors for the development of T2D in women.

Hypertension in pregnancy is associated with elevated C-reactive protein levels later in life

OBJECTIVES

We assessed whether hypertension in pregnancy is associated with elevated C-reactive protein (CRP) levels in later life, possibly reflecting an increased risk of cardiovascular disease (CVD).

BACKGROUND

Elevated CRP levels have been associated with hypertension in pregnancy and with CVD.

METHODS

We studied 2463 women from the Genetic Epidemiology Network of Arteriopathy (GENOA) study. Participants were categorized as nulliparous women (n = 219), women with a history of normotensive pregnancies (n = 1839), or women with a history of a hypertensive pregnancy (n = 405). Using multiple linear regression models, we compared mean CRP levels among the groups after adjusting for age, race, education, smoking, hypertension, personal history of coronary heart disease (CHD) or stroke, diabetes, dyslipidemia, statins, hormone replacement therapy, and family history of CHD or stroke. As CRP levels may be influenced by BMI, the model was fit both with and without adjusting for BMI.

RESULTS

There was no significant difference in CRP levels between nulliparous women and those with a history of normotensive pregnancies, either with (P = 0.82) or without (P = 0.46) adjusting for BMI. In contrast, women with hypertensive pregnancies, compared with those with normotensive pregnancies, had higher CRP levels, both with (P = 0.009) and without (P < 0.001) adjusting for BMI.

CONCLUSION

A history of hypertension in pregnancy is associated with elevated CRP levels later in life, independent of traditional CVD risk factors and BMI. An elevated CRP may reflect an inflammatory state in women with a history of hypertensive pregnancy disorders who are at increased risk for CVD.

Benefits and risks during HRT: main safety issue breast cancer

To assess the benefits and risks during hormone replacement therapy (HRT) in postmenopausal women, the only placebo-controlled study testing clinical endpoints with high statistical power has been the Women's Health Initiative (WHI). Although this trial, conducted mainly in older high-risk women, might not reflect the practical conditions for the normal use of HRT, the WHI for the first time provides the main risks in relative as well as in absolute numbers, which are venous thromboembolism and breast cancer, and in older women also myocardial infarction and stroke. Proven benefits such as treatment of climacteric symptoms, reduction of osteoporotic fractures and decrease of colon cancer risk seem to be only important for younger women, because only with early start of HRT cardiovascular risks can be reduced. Reduction of cardiovascular risks can be achieved using transdermal HRT, which, however, was not tested in a placebo-controlled study design similar to that in the WHI. This review focuses on the results of the WHI, comparing different age groups, and in general especially on the main fear of women, risk of breast cancer, which has been defined as a special project between two universities, a close collaboration of a German and Chinese research group.

Understanding the cognitive impact of the contraceptive estrogen Ethinyl Estradiol: tonic and cyclic administration impairs memory, and performance correlates with basal forebrain cholinergic system integrity

Ethinyl Estradiol (EE), a synthetic, orally bio-available estrogen, is the most commonly prescribed form of estrogen in oral contraceptives, and is found in at least 30 different contraceptive formulations currently prescribed to women as well as hormone therapies prescribed to menopausal women. Thus, EE is prescribed clinically to women at ages ranging from puberty to reproductive senescence. Here, in two separate studies, the cognitive effects of cyclic or tonic EE administration following ovariectomy (Ovx) were evaluated in young female rats. Study I assessed the cognitive effects of low and high doses of EE, delivered tonically via a subcutaneous osmotic pump. Study II evaluated the cognitive effects of low, medium, and high doses of EE administered via a daily subcutaneous injection, modeling the daily rise and fall of serum EE levels with oral regimens. Study II also investigated the impact of low, medium and high doses of EE on the basal forebrain cholinergic system. The low and medium doses utilized here correspond to the range of doses currently used in clinical formulations, and the high dose corresponds to doses prescribed to a generation of women between 1960 and 1970, when oral contraceptives first became available. We evaluate cognition using a battery of maze tasks tapping several domains of spatial learning and memory as well as basal forebrain cholinergic integrity using immunohistochemistry and unbiased stereology to estimate the number of choline acetyltransferase (ChAT)-producing cells in the medial septum and vertical/diagonal bands. At the highest dose, EE treatment impaired multiple domains of spatial memory relative to vehicle treatment, regardless of administration method. When given cyclically at the low and medium doses, EE did not impact working memory, but transiently impaired reference memory during the learning phase of testing. Of the doses and regimens tested here, only EE at the highest dose impaired several domains of memory; tonic delivery of low EE, a dose that corresponds to the most popular doses used in the clinic today, did not impact cognition on any measure. Both medium and high injection doses of EE reduced the number of ChAt-immunoreactive cells in the basal forebrain, and cell population estimates in the vertical/diagonal bands negatively correlated with working memory errors.

The role of cytokines in cardiovascular disease in menopause

Various studies suggest that increased levels of pro-inflammatory cytokines play a key role in the declining ovarian function and the resulting complications associated with menopause. In this review article, the authors outline the role of pro- and anti-inflammatory cytokines in cardiovascular disease during menopause.

Endogenous sex hormone changes in postmenopausal women in the diabetes prevention program

CONTEXT

Whether endogenous sex hormones (ESH) [SHBG, estradiol, testosterone, and dehydroepiandrosterone (DHEA)] are altered by intensive lifestyle modification (ILS) or metformin and whether such changes affect glucose levels among dysglycemic postmenopausal women is unclear.

OBJECTIVES

Our objective was to examine intervention impact on ESH and associations with fasting plasma glucose (FPG) and 2-h glucose changes among postmenopausal glucose-intolerant women.

DESIGN

We performed a secondary analysis of a randomized controlled trial.

PARTICIPANTS

Participants included postmenopausal, overweight, glucose-intolerant women not using exogenous estrogen (n = 382) who participated in the Diabetes Prevention Program.

INTERVENTIONS

Interventions included ILS with the goals of weight reduction of at least 7% of initial weight and 150 min/wk of moderate intensity exercise or metformin or placebo administered 850 mg twice a day.

MAIN OUTCOME MEASURES

Intervention-related changes in ESH and associations of changes in ESH and glucose levels were evaluated.

RESULTS

ILS significantly increased SHBG and decreased DHEA before and after adjustment for changes in waist circumference and fasting insulin. ILS did not alter estradiol or testosterone. Metformin did not change any ESH. ILS-induced increases in SHBG and declines in DHEA were associated with decreases in FPG and 2-h glucose, and declines in estradiol were associated with decreases in FPG, before and after adjustment for age, FSH, race/ethnicity, changes in waist circumference, and 1/fasting insulin.

CONCLUSIONS

Among postmenopausal glucose-intolerant women not using estrogen, ILS increased SHBG levels and lowered DHEA levels. These changes were associated with lower glucose independent of adiposity and insulin. Metformin effects upon ESH were not significant.

Endogenous reproductive hormones and C-reactive protein across the menstrual cycle: the BioCycle Study

C-reactive protein (CRP) is one of the most commonly used markers of acute phase reaction in clinical settings and predictors of cardiovascular risk in healthy women; however, data on its physiologic regulation in premenopausal women are sparse. The objective of this study was to evaluate the association between endogenous reproductive hormones and CRP in the BioCycle Study (2005-2007). Women aged 18-44 years from western New York were followed prospectively for up to 2 menstrual cycles (n = 259). Serum levels of CRP, estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone were measured up to 8 times per cycle, timed by fertility monitors. CRP levels varied significantly across the cycle (P < 0.001). More women were classified as being at elevated risk of cardiovascular disease (CRP, >3 mg/L) during menses compared with other phases (12.3% vs. 7.4%; P < 0.001). A 10-fold increase in estradiol was associated with a 24.3% decrease in CRP (95% confidence interval: 19.3, 29.0). A 10-fold increase in luteal progesterone was associated with a 19.4% increase in CRP (95% confidence interval: 8.4, 31.5). These results support the hypothesis that endogenous estradiol might have antiinflammatory effects and highlight the need for standardization of CRP measurement to menstrual cycle phase in reproductive-aged women.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Oral postmenopausal hormone therapy, C-reactive protein, and cardiovascular outcomes

OBJECTIVES

This study examines C-reactive protein (CRP) levels predicting cardiovascular events (CVEs) among hormone therapy (HT) users and nonusers.

METHODS

CRP levels are higher in women who use oral HT than those in nonusers; however, whether the same CRP cut-points determine increased cardiovascular risk remains unanswered. CRP was measured at baseline in 10,953 HT users and 15,838 nonusers in the Women's Health Study. In HT nonusers and users, Cox proportional hazard models adjusted for age, cardiovascular risk factors, body mass index, and menopause status were constructed using American Heart Association/Centers for Disease Control and Prevention recommended CRP cut-points for low, average, and high cardiovascular risk as well as HT nonuser- and user-derived quantiles of CRP to predict incident CVEs.

RESULTS

CVE risk increased with logarithm CRP for both HT users and nonusers. After adjusting for cardiovascular risk factors including lipids, the multivariable relative risk (RR) per log unit of CRP was 1.27 (95% CI, 1.13-1.44) for HT nonusers and 1.22 (95% CI, 1.07-1.40) for HT users. To compare the risk associated with American Heart Association/Centers for Disease Control and Prevention CRP categories across HT use groups, we fit a model in which nonusers with a CRP level lower than 1 mg/L were the reference group. After adjusting for other risk factors including lipids, HT users with a CRP level of 3 mg/L or higher had an RR of 1.93 (1.38-2.69), whereas nonusers had an RR of 1.92 (1.35-2.72).

CONCLUSIONS

CRP predicts CVE in a linear relationship among both HT users and nonusers. CRP levels of 3 mg/L or higher were associated with increased cardiovascular risk in both nonusers and HT users.

The association of endogenous sex hormones, adiposity, and insulin resistance with incident diabetes in postmenopausal women

CONTEXT

In postmenopausal women, endogenous bioavailable testosterone (T) and estradiol (E2) have been positively associated, and SHBG has been negatively associated, with incident type 2 diabetes (T2DM). Previous studies have not explored possible factors explaining these relationships.

OBJECTIVE

Our objective was to examine the association of endogenous sex hormones with incident T2DM in postmenopausal women and possible explanatory factors.

DESIGN, SETTING, AND PARTICIPANTS

The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective study that included 1612 postmenopausal women aged 45-84 yr, followed between the years 2000-2006, who were not taking hormone replacement therapy, had no prevalent cardiovascular disease or diabetes, and had complete ascertainment of sex hormones.

MAIN OUTCOME MEASURES

T2DM was defined based on fasting glucose and/or treatment for diabetes.

RESULTS

There were 116 incident cases of diabetes during follow-up. Across higher quartiles of bioavailable T and E2 and lower quartiles of SHBG, we found significantly greater hazards of developing incident T2DM (all P for trend <or=0.001). After adjustment for body mass index and insulin resistance estimated by homeostasis model assessment of insulin resistance, bioavailable T was no longer associated with incident T2DM. The associations of E2 and SHBG with incident T2DM were partially explained by body mass index and insulin resistance but persisted in fully adjusted models (both P for trend <0.02). Dehydroepiandrosterone had no relationship with incident T2DM.

CONCLUSIONS

Adiposity and insulin resistance explained most of the association of bioavailable T but only partially explained the associations of E2 and SHBG with incident T2DM among postmenopausal women.

High C‐reactive protein levels are associated with oral hormonal menopausal therapy but not with intrauterine levonorgestrel and transdermal estradiol

OBJECTIVE

Oral hormone replacement therapy (HRT) has been linked to increased cardiovascular (CVD) morbidity. HRT causes a sustained increase in C-reactive protein (CRP), an excellent marker of subclinical inflammation and CVD. The aim of the study was to support our hypothesis that CRP, which is synthesized in the liver, is not increased in association with transdermal/intrauterine HRT.

MATERIAL AND METHODS

A case-control study was performed in which CRP measurements in women receiving levonorgestrel intrauterine system combined with transdermal estradiol (LNG/TDE, n=27) were followed for 9 months or longer. CRP concentrations in these women were compared with those of either oral HRT users (n=20) or controls (n=19).

RESULTS

No significant differences were found in CRP concentrations between the LGN/TDE and control groups (1.8+/-1.2 and 1.8+/-1.8 mg/L, respectively). However, CRP was significantly increased in the oral HRT group (5.5+/-2.9 mg/L, p<0.001).

CONCLUSIONS

CRP is significantly increased by oral HRT but not by the LNG/TDE combination after 9 months of treatment. This trend may explain the preponderance of some menopausal women on HRT being at increased risk for the development of CVD. Therefore, the use of LNG/TDE is acceptable for relief of severe climacteric symptoms possibly not imposing an increased CVD risk documented upon oral HRT.

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.

Transdermal hormone therapy in postmenopausal women: a review of metabolic effects and drug delivery technologies

Vasomotor symptoms (VMS) associated with menopause can cause significant discomfort and decrease the quality of life for women in the peri-menopausal and post-menopausal stages of life. Hormone therapy (HT) is the mainstay of treatment for menopausal symptoms and is currently the only therapy proven effective for VMS. Numerous HT options are available to treat VMS, including estrogen-only and estrogen-progestogen combination products to meet the needs of both hysterectomized and nonhysterectomized women. In addition to selecting an appropriate estrogen or estrogen-progestogen combination, consideration should be given to the route of administration to best suit the needs of the patient. Delivery systems for hormone therapy include oral tablets, transdermal patches, transdermal topical (nonpatch) products, and intravaginal preparations. Oral is currently the most commonly utilized route of administration in the United States. However, evidence suggests that oral delivery may lead to some undesirable physiologic effects caused by significant gut and hepatic metabolism. Transdermal drug delivery may mitigate some of these effects by avoiding gut and hepatic first-pass metabolism. Advantages of transdermal delivery include the ability to administer unmetabolized estradiol directly to the blood stream, administration of lower doses compared to oral products, and minimal stimulation of hepatic protein production. Several estradiol transdermal delivery technologies are available, including various types of patches, topical gels, and a transdermal spray.

Could transdermal estradiol + progesterone be a safer postmenopausal HRT? A review

Hormone replacement therapy (HRT) in young postmenopausal women is a safe and effective tool to counteract climacteric symptoms and to prevent long-term degenerative diseases, such as osteoporotic fractures, cardiovascular disease, diabetes mellitus and possibly cognitive impairment. The different types of HRT offer to many extent comparable efficacies on symptoms control; however, the expert selection of specific compounds, doses or routes of administration can provide significant clinical advantages. This paper reviews the role of the non-oral route of administration of sex steroids in the clinical management of postmenopausal women. Non-orally administered estrogens, minimizing the hepatic induction of clotting factors and others proteins associated with the first-pass effect, are associated with potential advantages on the cardiovascular system. In particular, the risk of developing deep vein thrombosis or pulmonary thromboembolism is negligible in comparison to that associated with oral estrogens. In addition, recent indications suggest potential advantages for blood pressure control with non-oral estrogens. To the same extent, a growing literature suggests that the progestins used in association with estrogens may not be equivalent. Recent evidence indeed shows that natural progesterone displays a favorable action on the vessels and on the brain, while this might not be true for some synthetic progestins. Compelling indications also exist that differences might also be present for the risk of developing breast cancer, with recent trials indicating that the association of natural progesterone with estrogens confers less or even no risk of breast cancer as opposed to the use of other synthetic progestins. In conclusion, while all types of hormone replacement therapies are safe and effective and confer significant benefits in the long-term when initiated in young postmenopausal women, in specific clinical settings the choice of the transdermal route of administration of estrogens and the use of natural progesterone might offer significant benefits and added safety.

C-reactive protein across the menstrual cycle

C-reactive protein (CRP) is a widely used, sensitive biomarker of inflammation. Studies conducted among users of exogenous hormones suggest that estrogen increases CRP, whereas progesterone decreases CRP. Examinations of CRP in normally cycling women suggest the opposite: CRP is negatively associated with endogenous estrogen and positively associated with endogenous progesterone. This work evaluates the association between menstrual cycle-related hormone changes and events (menstruation and ovulation) and CRP. Eight female subjects gave urine and blood samples from twelve days across the menstrual cycle, for a total of eleven cycles. Blood samples were assayed for CRP; urine samples for beta-follicle stimulating hormone (betaFSH), pregnanediol 3-glucuronide (PDG), and estrone glucuronide (E1G). Ovulation day was estimated using hormone levels. Presence or absence of menses was reported by subjects. Analyses were conducted with random-effects linear regression. All cycles were ovulatory; day of ovulation was identified for nine cycles. A ten-fold increase in progesterone was associated with a 23% increase in CRP (P = 0.01), a ten-fold increase in estrogen was associated with a 29% decrease in CRP (P = 0.05), and menses was associated with a 17% increase in CRP (P = 0.18); no association between ovulation or FSH and CRP was found. Hormone changes across the menstrual cycle should be controlled for in future studies of inflammation in reproductive-age women.

Estrogen-mediated protection in myocardial ischemia-reperfusion injury

Before menopause, a woman has a relatively low risk for developing cardiovascular disease. After menopause, however, the risk increases nearly twofold and cardiovascular disease remains the number one cause of death among women. Observational trials and studies in animal models of cardiovascular disease suggested that females have reduced injury after myocardial ischemia and reperfusion injury. However, two large clinical trials, the women's health initiative (WHI) and the heart estrogen and progestin replacement study (HERS), found an increase in cardiovascular incidences in women taking hormone replacement therapy. The discrepancy between these data highlights the need for further research on the mechanism of estrogen in the cardiovascular system. Animal studies have demonstrated protective effects by endogenous estrogen (gender differences) and also by the administration of exogenous estrogen. In vivo studies suggest a possible anti-inflammatory mechanism of estrogen. Exogenous estrogen has been shown to have anti-oxidant activities. Pre-treatment with estrogen prior to myocardial ischemia and reperfusion causes a decrease in neutrophil infiltration into the irreversibly injured myocardium, decrease in C-reactive protein expression, and deposition of the membrane attack complex. This review will summarize the protection afforded by estrogen as well as discuss several possible mechanisms of protection for exogenous estrogen administration.

17Beta-estradiol increases basal but not bradykinin-stimulated release of active t-PA in young postmenopausal women

Angiotensin-converting enzyme inhibition potentiates basal and bradykinin-stimulated tissue-type plasminogen activator (t-PA) release to a greater extent in women than in men. This study tested the hypothesis that 17beta-estradiol enhances the effect of angiotensin-converting enzyme inhibition on t-PA release in young postmenopausal women. We conducted a double-blind, prospective, crossover study in 14 young postmenopausal women (mean age 48.2+/-2.3 years) who were randomized to receive 17beta-estradiol (1 mg/d) or matching placebo for 4 weeks. At the end of each treatment period, we measured the effect of intraarterial infusion of bradykinin, methacholine, and nitroprusside on forearm blood flow and net t-PA release, before and during intraarterial enalaprilat (0.33 microg/min/100 mL forearm volume). 17Beta-estradiol significantly reduced baseline venous plasminogen activator inhibitor-1 antigen (4.4+/-1.4 versus 10.4+/-2.5 ng/mL, P=0.001) and t-PA antigen (5.5+/-0.6 versus 7.5+/-1.3 ng/mL, P=0.022) compared with placebo. 17Beta-estradiol increased basal forearm vascular release of active t-PA compared with placebo (1.2+/-0.3 IU/mL/min versus 0.4+/-0.1 IU/mL/min respectively, P=0.032), without increasing t-PA antigen release (P=0.761). Enalaprilat significantly increased basal net t-PA antigen release (from -0.8+/-1.0 to 3.2+/-1.2 ng/min/100 mL, P=0.012), but not the release of active t-PA, during either placebo or 17beta-estradiol. Enalaprilat potentiated bradykinin-stimulated vasodilation and t-PA antigen and activity release similarly during placebo and 17beta-estradiol treatment. 17Beta-estradiol treatment does not alter the effect of angiotensin-converting enzyme inhibition on basal t-PA antigen or on bradykinin-stimulated t-PA antigen or activity release. 17Beta-estradiol increases basal release of active t-PA in young postmenopausal women, consistent with enhanced vascular fibrinolytic function.

Effects of non-oral postmenopausal hormone therapy on markers of cardiovascular risk: a systematic review

OBJECTIVE

To review the effects of non-oral administration of postmenopausal hormone therapy (HT) on risk markers for atherosclerotic and venous thromboembolic disease.Non-oral postmenopausal HT appears not to increase venous thromboembolic risk, whereas the effect on coronary heart disease risk is less clear.

DESIGN

Systematic review of literature obtained from MEDLINE, EMBASE, and CENTRAL databases from 1980 until and including April 2006. Terms for "postmenopausal hormone therapy" and for "non-oral administration" were combined in the search.

SETTING

Randomized clinical trials.

PATIENT(S)

Postmenopausal women, both healthy and with established cardiovascular disease or specified cardiovascular risk factors

INTERVENTION(S)

Non-oral HT (e.g., transdermal or intranasal) compared with oral HT or no treatment/placebo.

MAIN OUTCOME MEASURE(S)

Lipoprotein(a), homocysteine, C-reactive protein (CRP), cell adhesion molecules, markers of endothelial dysfunction, coagulation, and fibrinolysis.

RESULT(S)

Seventy-two studies investigating either transdermal or intranasal administration were included. For non-oral HT, decreases in lipoprotein(a), cell adhesion molecules, and factor VII generally were significant, resistance to activated protein C (APCr) was slightly increased, and other markers including CRP and homocysteine did not change. Compared with oral HT, changes in CRP and APCr were smaller, changes in cell adhesion molecules and some fibrinolytic parameters tended to be smaller, whereas changes in other factors including lipoprotein(a) and homocysteine did not differ.

CONCLUSION(S)

Potentially unfavorable changes seen with oral HT on two important markers, CRP and APCr, are substantially smaller with non-oral HT. Non-oral HT has minor effects on the other cardiovascular risk markers studied. Therefore, compared with oral HT, non-oral HT appears be safer with respect to atherosclerotic and venous thromboembolic disease risk.

Plasma sex steroid hormones and risk of developing type 2 diabetes in women: a prospective study

AIMS/HYPOTHESIS

Prospective data directly investigating the role of endogenous sex hormones in diabetes risk have been scant, particularly in women. We aimed to examine comprehensively plasma sex hormones in connection with risk of developing type 2 diabetes in postmenopausal women.

METHODS

We conducted a prospective, nested case-control study of plasma oestradiol, testosterone and dehydroepiandrosterone sulfate and risk of type 2 diabetes in a cohort of women health professionals with a mean age of 60.3 and 12.2 years since menopause. Among women not using hormone therapy and free of baseline cardiovascular disease, cancer and diabetes, 359 incident cases of type 2 diabetes were matched with 359 controls during an average follow-up of 10 years.

RESULTS

Oestradiol and testosterone were each strongly and positively associated with risk of type 2 diabetes. After adjustment for BMI, family history, lifestyle and reproductive variables, the multivariable relative risks (95% CI) comparing the highest vs lowest quintile were 12.6 (2.83-56.3) for total oestradiol (p = 0.002 for trend), 13.1 (4.18-40.8) for free oestradiol (p < 0.001 for trend), 4.15 (1.21-14.2) for total testosterone (p = 0.019 for trend) and 14.8 (4.44-49.2) for free testosterone (p < 0.001 for trend). These associations remained robust after adjusting and accounting for other metabolic syndrome components and baseline HbA(1c) levels.

CONCLUSIONS/INTERPRETATION

In postmenopausal women, higher plasma levels of oestradiol and testosterone were strongly and prospectively related to increased risk of developing type 2 diabetes. These prospective data indicate that endogenous levels of sex hormones may play important roles in the pathogenesis of type 2 diabetes. ClinicalTrials.gov ID no.: NCT00000479.

Randomized Dose-Ranging Trial of Tamoxifen at Low Doses in Hormone Replacement Therapy Users

Purpose

The combination of hormone replacement therapy (HRT) and low-dose tamoxifen may retain the benefits while reducing the risks of either agent. We assessed the optimal biologic dose and schedule of tamoxifen in HRT users using surrogate end point biomarkers and menopausal symptoms.

Subjects and Methods

Two hundred ten current or de novo HRT users were randomly assigned to one of the following four arms: tamoxifen 1 mg/day and placebo/week, placebo/day and tamoxifen 10 mg/week, tamoxifen 5 mg/day and placebo/week, or both placebos for 12 months. The primary end point was the change of plasma insulinlike growth factor 1 (IGF-I) through 12 months, and secondary end points were IGF-I/IGF binding protein-3 (IGFBP-3) ratio, fibrinogen, antithrombin III, C reactive protein, C-telopeptide, mammographic percent density, and endometrial thickness. Endometrial proliferation was assessed by Pipelle biopsy in superficial, deep glandular, and stromal compartments after 12 months.

Results

Compared with placebo, IGF-I declined in all tamoxifen arms (P = .005), with a greater change on 5 mg/day (P = .019 v 10 mg/week or 1 mg/day). Tamoxifen increased IGFBP-3 and lowered antithrombin-III, C reactive protein, and mammographic density, with greater effects of 5 mg/day. Tamoxifen increased endometrial thickness but not Ki-67 expression, which was lower on 5 mg/day among the three doses. Menopausal symptoms were not significantly worsened by tamoxifen.

Conclusion

Doses of tamoxifen ≤ 5 mg/day modulate favorably biomarkers of breast carcinogenesis and cardiovascular risk in HRT users with no increase of endometrial proliferation and menopausal symptoms. A dose of 5 mg/day was the most effective and has been selected for a phase III trial in HRT users.

Hormonal replacement therapy (HRT) in postmenopause: a reappraisal

Hormone replacement therapy (HRT) is the most effective treatment currently available for vasomotor and urogenital symptoms and decreased libido. Because harmful effects were evidenced in some clinical trials, health authorities now consider that risk-benefit considerations do not favour the use of HRT for prevention of cardiovascular diseases and bone fractures in postmenopausal women. However, experimental and clinical studies indicate that adverse effects of HRT may largely depend on the estrogen and progesterone/progestin formulation, dosage, mode of administration, patient's age, associated diseases, and duration of treatment. All estrogen formulations and modes of administration have similar beneficial effects on vasomotor and urogenital symptoms and on bone structure. But cardiovascular and invasive breast cancer risks are higher with oral estrogen than with transdermal estradiol, and also higher with many progestin compounds than with micronized progesterone. The combination of transdermal estradiol+micronized progesterone appears to be effective and relatively safe if elementary precautions are taken, and seems to be presently the best choice for HRT in most postmenopausal women. In the author's--heterodox--opinion, HRT may also be a good therapeutic choice to prevent bone loss, since alternative medications, including raloxifene and bisphosphonates, may have dramatic harmful effects in some patients. It might also have beneficial effects on the development of coronary disease in young postmenopausal women. HRT requires careful adjustment to each individual patient and continuous monitoring of clinical evolution. In the future, this adjustment could benefit from genetic screening to maximize in each individual the ratio between positive and adverse effects.

[Hormone replacement therapy for internal risk patients]

Using hormone replacement therapy (HRT), absolute and relative contradictions have to be considered, which are primarily classified according to a "worst case" scenario on the assumption of group effects, in order to satisfy forensic demands. However, in patients with severe complaints it make sense to apply HRT even at increased risk. To minimize the risk, a differentiated choice of the preparation especially in terms of progestin component and application mode is feasible apart from a general dose reduction. For internal risk patients, transdermal estradiol in a patch or gel and neutral progestins like progesterone and dydrogesterone or combination patches for a completely transdermal HRT are to be preferred. In the Women's Health Initiative, a study investigating a population strongly burdened with cardiovascular risks, the most important risks were venous thromboses and strokes, in old age also myocardial infarctions. In this context, the risk groups with diabetes, hypertension and dyslipoproteinemia as well as smokers in general are of particular importance. Other common internal risk groups comprise women with thyroid and hepatobiliary diseases. Rare but prognostically important diseases such as porphyria and lupus erythematosus are considered as relative contraindications. The available data on these risk groups are described and practical recommendations are given.

Estrogen therapy and thrombotic risk

Post-menopausal hormone therapy increases the risk for venous thrombosis, and possibly myocardial infarction (MI) and ischemic stroke. However, most women using hormone therapy do not suffer thrombosis, and to date our ability to identify women at risk is limited. Thrombosis, arterial or venous, has 2 requisites: a vascular anomaly and a response of the hemostasis system to the anomaly. Consequently, experimental approaches to understand the pathophysiology of thrombosis require definition of vascular anatomy and function as well as characteristics of the blood within the context of genetic background, lifestyle choices and environmental exposures, which influence gene expression. Defining interactions among factors that affect individual propensity to thrombosis will allow physicians to better identify at-risk individuals, for example a woman contemplating estrogen therapy for symptoms of menopause, and prevent adverse thrombotic events.

Effects of intranasal 17β-estradiol administration on serum bioactive interleukin-6 and C-reactive protein levels in healthy postmenopausal women

OBJECTIVE

Oral estrogen increases the levels of C-reactive protein (CRP), which is an independent risk factor for coronary heart disease in healthy individuals. The aim of our study was to investigate the effects of intranasal 17beta-estradiol (E2) on serum CRP and its most potent stimulant, interleukin-6 in healthy postmenopausal women.

DESIGN

Thirty-six healthy postmenopausal women (45-54 y) were enrolled. According to their individual preferences, they were assigned to intranasal (n = 10), transdermal (n = 14), or oral (n = 12) continuous E2 treatment with a sequential progestin (10-14 d in a 28-d cycle). Blood samples were drawn at baseline and after 3, 6, and 12 months during the estrogen-only phase to adjust for the progestin effect.

RESULTS

In women taking intranasal or transdermal E2, there were no significant changes in median serum CRP levels during the 12-month treatment period. In women taking oral E2 preparations, serum median CRP levels were significantly higher compared to baseline after 6 and 12 months of the therapy (P < 0.05). Conversely, serum median bioactive interleukin-6 levels were significantly lower after 6 and 12 months in women taking E2 intranasally or orally and after 12 months in women taking E2 transdermally (P < 0.05).

CONCLUSIONS

The results of our study show that intranasal, similarly to transdermal, E2 administration does not increase serum CRP levels in postmenopausal women. They also support the hypothesis that CRP increase during oral estrogen treatment is not mediated by the enhancement of interleukin-6 production by the immune cells but is rather caused by the hepatic first-pass metabolism effect.

Postmenopausal hormone therapy: new questions and the case for new clinical trials

Observational studies suggest that postmenopausal hormone therapy (HT) prevents coronary heart disease, whereas randomized clinical trials have not confirmed a cardioprotective effect. Although observational studies may have overestimated the coronary benefit conferred by postmenopausal hormone use, there are other plausible explanations for the apparent discrepancy between previous results and the less favorable findings from clinical trials such as the large Women's Health Initiative. There is now a critical mass of data to support the hypothesis that age or time since menopause may importantly influence the benefit-risk ratio associated with HT, especially with respect to cardiovascular outcomes, and that the method of administration, dose, and formulation of exogenous hormones may also be relevant. Although the weight of the evidence indicates that older women and those with subclinical or overt coronary heart disease should not take HT, estrogen remains the most effective treatment currently available for vasomotor symptoms, and its effects on the development of coronary disease in newly postmenopausal women remain unclear. Moreover, effects of HT on quality of life and cognitive function in recently postmenopausal women merit further study. These unresolved clinical issues provide the rationale for the design of the Kronos Early Estrogen Prevention Study, a 5-year randomized trial that will evaluate the effectiveness of low-dose oral estrogen and transdermal estradiol in preventing progression of atherosclerosis in recently postmenopausal women.

High-Sensitivity C-Reactive Protein and Cognitive Function in Older Women

BACKGROUND

Inflammatory processes may be involved in the development of dementia, although findings from epidemiologic studies directly examining inflammatory markers and dementia or its precursor, impaired cognitive function, are inconsistent.

METHODS

We measured plasma levels of the inflammatory marker, C-reactive protein, using a high-sensitivity assay (hs-CRP) in 4,231 older participants of the Women's Health Study, who provided blood samples between 1992 and 1996 when they were age 60 to 90 years. From 1998 to 2000, we administered a battery of 5 cognitive tests measuring general cognition, verbal memory, and category fluency. Using multiple linear regression, we compared mean cognitive test scores across quintiles of hs-CRP, adjusting for potential confounding factors.

RESULTS

There was a wide distribution of hs-CRP levels among these women, and a large proportion had levels considered to reflect a high risk of cardiovascular disease. We observed no suggestion, however, that higher hs-CRP levels were associated with poorer cognitive performance. For example, on a global score combining results of all the cognitive tests, mean scores among women in the highest quintile of hs-CRP did not differ from those in the lowest quintile (multivariable-adjusted mean difference = 0.04; 95% confidence interval [CI]: -0.02 to 0.11, P for trend across quintiles = 0.38).

CONCLUSION

Overall, in these women, we found no evidence of a link between hs-CRP, a marker of inflammation, and decrements in cognitive function.

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.

Quality of life assessment in a chemoprevention trial: fenretinide and oral or transdermal HRT

BACKGROUND

Oral conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA) relief menopause symptoms, but may increase breast cancer risk, while the effects of transdermal estradiol (E2) and MPA are less known. In previous studies, fenretinide decreased second breast malignancies in premenopausal but not in postmenopausal women, suggesting a hormone-sensitizing effect. We have evaluated the quality of life through a self-administered questionnaire during a randomized study of oral CEE or transdermal E2 and fenretinide or placebo.

METHODS

A total of 226 postmenopausal women were randomly assigned to either CEE 0.625mg/day and placebo (n=55), or CEE and fenretinide 100mg/bid (n=56), or E2, 50microg/day and placebo (n=59), or E2 and fenretinide (n=56) for 12 months. Sequential MPA 10mg/day was added in all groups. Treatment effects were investigated using a validated questionnaire, the Menopause Quality of Life questionnaire (MENQOL).

RESULTS

Oral CEE and transdermal E2 have a comparable activity in reducing menopausal symptoms (p=ns). Both routes ameliorate significantly the symptoms after 1 year of treatment (p<0.0001). Fenretinide does not modify the effects of hormonal replacement therapy.

CONCLUSIONS

Oral CEE and transdermal E2 have similar effect on menopausal symptoms relief. The choice of the best estrogen replacement therapy (ERT) route should be decided based on a careful analysis of all the clinical aspects of every subject, considering that transdermal therapy may have a safer effect on the cardiovascular system.

A critique of the Women's Health Initiative hormone therapy study

OBJECTIVE

This review critiques The Women's Health Initiative (WHI) study, focusing on aspects of the study design contributing to the adverse events resulting in the study's discontinuation.

CONCLUSION(S)

Two aspects of the design contributed to the adverse events: [1] The decision to administer continuous combined conjugated equine estrogen (CEE)/medroxyprogesterone acetate (MPA) or E alone as a standard regimen to a population with little previous hormonal treatment, ranging in age from 50-79 years, who, because of their age, were predisposed to coronary and cerebral atherosclerosis. [2] Selection of an untested regimen of continuous combined CEE plus MPA, which we hypothesize, negated the protective effect of E on the cardiovascular and cerebrovascular systems. Multiple observational studies that preceded the WHI study concluded that the use of E alone and E plus cyclic (not daily) progestin combination treatments initiated in early menopause had beneficial effects. The therapeutic regimens resulted in prevention of atherosclerosis and reductions in coronary artery disease mortality. It is our conclusion that the WHI hormonal replacement study had major design flaws that led to adverse conclusions about the positive effects of hormone therapy. An alternative hormonal regimen is proposed that, on the basis of data supporting its beneficial cardiovascular effects, when initiated appropriately in a population of younger, more recently menopausal women, has promise to yield a more favorable risk/benefit outcome.

Maternal C-reactive protein levels in patients undergoing frozen embryo replacement cycles: a prospective study

This prospective study shows that the early pregnancy inflammatory response following frozen embryo replacement (FER) cycles may be absent or suppressed, in contrast to that following IVF. To our knowledge, this is the first study to evaluate the maternal inflammatory response following FER cycles, but larger studies are still required to explore this novel finding, and investigate whether this may explain the lower ongoing pregnancy rates generally achieved following FER cycles.

Effects of Transdermal Estrogen Replacement Therapy on Cardiovascular Risk Factors

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

Pharmacology of estrogens and progestogens: influence of different routes of administration

This review comprises the pharmacokinetics and pharmacodynamics of natural and synthetic estrogens and progestogens used in contraception and therapy, with special consideration of hormone replacement therapy. The paper describes the mechanisms of action, the relation between structure and hormonal activity, differences in hormonal pattern and potency, peculiarities in the properties of certain steroids, tissue-specific effects, and the metabolism of the available estrogens and progestogens. The influence of the route of administration on pharmacokinetics, hormonal activity and metabolism is presented, and the effects of oral and transdermal treatment with estrogens on tissues, clinical and serum parameters are compared. The effects of oral, transdermal (patch and gel), intranasal, sublingual, buccal, vaginal, subcutaneous and intramuscular administration of estrogens, as well as of oral, vaginal, transdermal, intranasal, buccal, intramuscular and intrauterine application of progestogens are discussed. The various types of progestogens, their receptor interaction, hormonal pattern and the hormonal activity of certain metabolites are described in detail. The structural formulae, serum concentrations, binding affinities to steroid receptors and serum binding globulins, and the relative potencies of the available estrogens and progestins are presented. Differences in the tissue-specific effects of the various compounds and regimens and their potential implications with the risks and benefits of hormone replacement therapy are discussed.

Short-term effects of hormone therapy on serum C-reactive protein levels in postmenopausal women

OBJECTIVES

The aim of this study was to investigate the effects of tibolone and conjugated equine estrogens (CEEs) plus medroxyprogesterone acetate (MPA) (CEE + MPA) on levels of serum C-reactive protein (CRP), an independent risk factor for cardiovascular disorders, in postmenopausal women.

STUDY DESIGN

In this prospective randomized study, we randomly assigned 58 healthy postmenopausal women to CEE (0.625 mg/day) plus MPA (2.5 mg/day) (CEE + MPA) or tibolone (2.5 mg/day). The serum levels of CRP at 3 months after starting treatment were compared with baseline values for both therapies.

RESULTS

After 3 months of treatment the median CRP levels increased by 29% in the CEE + MPA group and by 5% in the tibolone group. But, these changes did not have statistical significance (P=0.15, P=0.06, respectively).

CONCLUSIONS

Our findings show that neither tibolone nor CEE + MPA caused significant changes in serum CRP levels in postmenopausal women. The potential impact of hormone therapy on serum CRP levels should be investigated in ongoing clinical trials.

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.

Sex hormone-binding globulin and serum testosterone are inversely associated with C-reactive protein levels in postmenopausal women at high risk for cardiovascular disease

PURPOSE

C-reactive protein (CRP), androgens, and menopausal loss of endogenous estrogens are associated with cardiovascular disease (CVD). We hypothesized that high androgens, low estradiol, and low sex hormone-binding globulin (SHBG) would be associated with high CRP in postmenopausal women.

METHODS

CRP, SHBG, estradiol, and total testosterone were measured using baseline bloods of 221 hormone therapy (HT)-nonusers and 162 HT-users from a cross-sectional analysis in a nested case-control sample of the Women's Health Study. Hormones and CRP were ln-transformed and relationships were assessed with Spearman correlations and linear regression.

RESULTS

ln-SHBG (beta=-0.40; p<0.01) and ln-testosterone (beta=-0.24; p=0.04) were the only independent hormonal predictors of ln-CRP among HT-nonusers after adjusting for age, hypertension, smoking, body mass index, diabetes, exercise, HDL cholesterol, alcohol intake, and CVD occurrence during follow-up. Upon stratification, the association between ln-SHBG and ln-CRP persisted among HT nonusers who subsequently developed CVD (beta=-0.55; p=0.01), but not among women who remained CVD-free (p=0.28). The inverse relationship between ln-SHBG and ln-CRP was strongest among the leanest women. None of the sex-hormones predicted ln-CRP among HT-users.

CONCLUSIONS

SHBG and total testosterone were inversely associated with CRP among HT nonusers in this study. The relationship between SHBG and CRP was more strongly inverse among leaner women.

New evidence regarding hormone replacement therapies is urgently required

Controversies about the safety of different postmenopausal hormone therapies (HTs) started 30 years ago and reached a peak in 2003 after the publication of the results from the Women Health Initiative (WHI) trial and the Million Women Study (MWS) [Writing group for the women's health initiative investigations. Risks and benefits of estrogen plus progestin in healthy postmenopausal women. JAMA 2002;288:321-33; Million women study collaborators. Breast cancer and hormone-replacement therapy in the million women study. Lancet 2003;362:419-27]. The single HT formulation used in the WHI trial for non hysterectomized women-an association of oral conjugated equine estrogens (CEE-0.625 mg/day) and a synthetic progestin, medroxyprogesterone acetate (MPA-2.5 mg/day)-increases the risks of venous thromboembolism, cardiovascular disease, stroke and breast cancer. The MWS, an observational study, showed an increased breast cancer risk in users of estrogens combined with either medroxyprogesterone acetate (MPA), norethisterone, or norgestrel. It is unclear and questionable to what extent these results might be extrapolated to other HRT regimens, that differ in their doses, compositions and administration routes, and that were not assessed in the WHI trial and the MWS. Significant results were achieved with the publication of the WHI estrogen-only arm study [Anderson GL, Limacher M, Assaf AR, et al. Effects of conjugated equine estrogen in postmenopausal women with hysterectomy: the Women's Health Initiative randomized controlled trial. JAMA 2004;291:1701-1712] in which hormone therapy was reserved to women who had carried out hysterectomy. What emerged from this study will allow us to have some important argument to develop.

Effect of transdermal hormone replacement therapy on the monocyte chemoattractant protein-1 concentrations and other vascular inflammatory markers and on endothelial function in postmenopausal women

Monocyte chemoattractant protein-1 (MCP-1) is related to the progression of atherosclerosis. However, little is known about the effects of transdermal hormone replacement therapy (HRT) on circulating MCP-1, vascular inflammatory marker concentrations, and endothelial function in postmenopausal women. The effects of transdermal HRT on circulating MCP-1, vascular inflammatory marker concentrations, and endothelium-dependent vasodilation were investigated in postmenopausal women. Thirty-three women received transdermal HRT (continuous 17-beta estradiol patch 36 microg/day plus cyclic oral medroxyprogesterone acetate 2.5 mg/day for 12 days/month) for 12 months, and 27 control patients did not. Brachial artery flow-mediated vasodilation (FMD), assessed by ultrasound, and circulating MCP-1 and vascular inflammatory marker (C-reactive protein, intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], and E-selectin) concentrations were measured before and after 12 months of treatment. In the HRT group, MCP-1 concentrations decreased significantly (p <0.001), and ICAM-1, VCAM-1, and E-selectin concentrations decreased significantly (p <0.01 for all), but C-reactive protein concentrations did not change. MCP-1 and other marker concentrations did not change in the control group. FMD increased significantly in the HRT group (p <0.001) but did not change in the control group. Nitroglycerin-induced vasodilation did not change in either group. In conclusion, transdermal HRT decreased MCP-1 and cell adhesion molecule concentrations and improved endothelial function in postmenopausal women. Transdermal HRT may exert an antiatherosclerotic effect by improving MCP-1 and cell adhesion molecule expression and endothelial function.

Clinical Pharmacology and Differential Cognitive Efficacy of Estrogen Preparations

Menopause is associated with a significant decline in levels of estrogen, which reportedly leads to several distressing symptoms and adverse health effects on various target tissues including those on bones, heart, and brain. Although effective, the long-term safety and feasibility of therapy with both unopposed and opposed oral conjugated equine estrogen has been questioned by the recent findings of both the Women's Health Initiative (WHI) and the Women's Health Initiative Memory Study (WHIMS). The findings of both these studies have raised several critical issues related to hormone therapy that need to be systematically evaluated in clinical studies. Specifically, these issues relate to the differential efficacy and adverse-effects profile of various forms of estrogen and progestins, the importance of the route of administration of estrogen, the best timing to initiate postmenopausal hormone therapy, and the efficacy of cyclic versus continuous hormone therapy. This article focuses on estrogen and discusses issues related to selecting the best form and route of administration of the hormone. It includes information on basic clinical pharmacology of various forms of estrogen, neuroendocrinology of the menopause, neurobiology of estradiol and estrone, and results of selected basic science and human intervention studies with relevance to identifying the best form and route of administration of estrogen.

Effects of two continuous hormone therapy regimens on C-reactive protein and homocysteine

OBJECTIVE

To compare the effects of two continuous hormone therapy (HT) regimens on the cardiovascular risk markers, C-reactive protein (CRP) and homocysteine.

DESIGN

A prospective study in which 43 postmenopausal women were randomly assigned to either tibolone 2.5 mg/day (n = 20) or 0.625 mg/day conjugated equine estrogens (CEE) plus continuous medroxyprogesterone acetate (MPA) 5 mg/day (n = 23). Serum levels of CRP, homocysteine, vitamin B12, and folate were determined before and during 12 weeks of therapy.

RESULTS

C-reactive protein levels were increased by tibolone (76%; P < 0.001) and CEE+MPA (81%; P < 0.001). Neither tibolone nor CEE+MPA had any significant effect on homocysteine levels, but there was a significant difference between the effects of treatment over time (P = 0.046). Both tibolone and CEE+MPA reduced vitamin B12 levels (11%; P < 0.001, and 8%; P < 0.01, respectively), but had no statistically significant effect on folate levels. Individual changes in homocysteine levels were negatively associated with changes in vitamin B12 levels (r = -0.68; P < 0.01) after tibolone therapy.

CONCLUSION

Both tibolone and CEE plus MPA increased CRP levels and reduced levels of vitamin B12. Neither therapy had any significant effect on homocysteine levels. Further long-term studies into the effect of HRT on these markers, and the relationship to cardiovascular disease risk, are required.

Hormone therapy and Alzheimer’s disease: benefit or harm?

Alzheimer's disease (AD) is the most common cause of dementia. After menopause, circulating levels of oestrogens decline markedly and oestrogen influences several brain processes predicted to modify AD risk. For example, oestrogen reduces the formation of beta-amyloid, a biochemical hallmark of AD. Oestrogen effects on oxidative stress and some effects on inflammation and the cerebral vasculature might also be expected to ameliorate risk. However, AD pathogenesis is incompletely understood and other oestrogen actions could be deleterious. Limited clinical trial evidence suggests that oestrogen therapy, begun after the onset of AD symptoms, is without substantial benefit or harm. Observational studies have associated oestrogen-containing hormone therapy with reduced AD risk. However, in the Women's Health Initiative Memory Study - a randomised, placebo-controlled trial of women 65 - 79 years of age - oral oestrogen plus progestin doubled the rate of dementia, with heightened risk appearing soon after treatment was initiated. Based on current evidence, hormone therapy is thus not indicated for the prevention of AD. Discrepancies between observational studies and the Women's Health Initiative clinical trial may reflect biases and unrecognised confounding factors in observational reports. Other explanations for divergent findings should be considered in future research, including effects of unopposed oestrogen or different hormone therapy preparations and the intriguing theoretical possibility that effects of hormone therapy on AD risk may be modified by the timing of use (e.g., initiation during the menopausal transition or early postmenopause versus initiation during the late postmenopause).

Postmenopausal hormone therapy: Critical reappraisal and a unified hypothesis

OBJECTIVE

To reconcile apparently conflicting evidence regarding the use of hormone therapy as a health-preserving strategy in postmenopausal women in light of that fact that findings from animal studies, human observation studies, and human clinical trials are consistent for outcomes such as fracture and breast cancer but differ for coronary heart disease (CHD).

DESIGN

Literature review and generation of a unified hypothesis consistent with all of the data.

SETTING

Animal trials, human observational studies, human studies of biologic intermediates, and human clinical trials.

PATIENT(S)

Premenopausal and postmenopausal women with or without antecedent CHD.

MAIN OUTCOME MEASURE(S)

Coronary heart disease events, proxies, risk factors, and related mechanisms.

RESULT(S)

The complex CHD responses to hormone therapy in recent human trials likely reflect a combination of [1] early erosion/rupture of "vulnerable" coronary plaque, which is made worse by hormone therapy, [2] long-term reduction in plaque formation, which is improved by hormone therapy, and [3] modulation of the vasculoprotective actions of estrogens by systemic progestogens.

CONCLUSION(S)

The unified hypothesis predicts that hormone therapy initiated at the time of menopause should produce a decrease in CHD over time. In contrast, hormone therapy begun years after menopause should produce an increase in CHD events shortly after therapy is begun, followed later by benefit. In women who require progestogens for endometrial protection, there should be greater CHD benefit from use of progestogens with less systemic activity. The unified hypothesis is consistent both with plausible biologic mechanisms and with evidence from animal studies, human observational studies, and human clinical trials such as the Women's Health Initiative. In the absence of evidence from human trials that specifically involve initiation of hormone therapy in perimenopausal women, practitioners and patients can use the unified hypothesis as a rational tool to guide decisions about clinical management.

Factors associated with circulating levels of insulin-like growth factor-I and insulin-like growth factor binding protein-3 in 740 women at risk for breast cancer

Prospective studies have shown an association between elevated plasma levels of insulin-like growth factor-I (IGF-I) and/or decreased levels of its major circulating carrier protein insulin-like growth factor binding protein-3 (IGFBP-3) and increased risk of major cancers. Identifying the factors which affect these biomarkers is of particular interest as subjects at increased risk could benefit from lifestyle changes, and/or chemoprevention intervention. We evaluated the association between constitutional, hormonal and clinical factors and IGF-I and IGFBP-3 in 740 women, including 376 unaffected women and 364 women with intraepithelial neoplasia (IEN) or early invasive breast cancer enrolled in breast cancer chemoprevention trials, conducted at a single institution. Age, body mass index (BMI), height, waist to hip girth ratio (WHR), parity, menopausal status, age at menarche, number of affected first degree relatives, number of biopsies and breast cancer status were considered in the analysis. Women with early breast cancer had 21% higher IGF-I levels (p = 0.033) and 19% higher IGF-I/IGFBP-3 molar ratio (p = 0.047) than unaffected women. In unaffected women, age was negatively associated with IGF-I (p = 0.002) and IGF-I/IGFBP-3 (p = 0.001), while age at menarche was negatively associated with IGFBP-3 levels (p = 0.043). In women with IEN or early breast cancer, IGF-I levels were negatively associated with age (p < 0.001), and positively associated with prior biopsies for benign disease (p = 0.013), while age, parity and menopausal status were significant predictors of IGF-I/IGFBP-3 molar ratio. We conclude that circulating IGF-I levels are higher in women with prior breast cancer compared to unaffected women, and that IGF-I and/or IGFBP-3 levels are influenced by age and by reproductive and hormonal factors. These findings support their putative role as breast cancer risk biomarker.