Effect of estrogen plus progestin on global cognitive function in postmenopausal women: the Women's Health Initiative Memory Study: a randomized controlled trial

Contrasting Effects of Oral Versus Transdermal Estrogen on Serum Amyloid A (SAA) and High-Density Lipoprotein–SAA in Postmenopausal Women

Objectives— Previous studies indicated that oral estrogen increased C-reactive protein by a first-pass hepatic effect. In this study, we determine whether the route of estrogen administration influences serum amyloid A (SAA), another acute-phase protein produced by the liver, and the SAA content of the high-density lipoprotein (HDL-SAA) in postmenopausal women.

Methods and Results— In 29 postmenopausal women without coronary heart disease, we conducted a randomized crossover placebo-controlled study to compare effects of transdermal versus oral estrogen on SAA and HDL-SAA. SAA, apolipoprotein A-I, HDL, and HDL-SAA were measured before and after 8 weeks of transdermal estradiol (100 μg per day), oral-conjugated estrogens (0.625 mg per day), or placebo. We found that oral estrogen significantly increased levels of SAA, HDL, and HDL-SAA, whereas transdermal estrogen reduced both SAA and HDL-SAA but had no effect on HDL in the same women.

Conclusions— Oral estrogen increased SAA and altered HDL composition to contain a higher level of SAA by a first-pass hepatic mechanism. Because elevated SAA levels predict adverse prognosis in healthy postmenopausal women, and elevated HDL-SAA levels have been shown to interfere with HDL function, the route of administration may be an important consideration in minimizing side effects of estrogen replacement therapy on cardiovascular outcomes.

Risk factors for vascular dementia and Alzheimer disease

Alzheimer disease and vascular cognitive impairment are important causes of cognitive decline in the elderly. It has now been shown that vascular risk factors have measurable negative effects on the brain and are associated with cognitive impairment. We review vascular factors that might be responsible to cognitive decline in Alzheimer disease and vascular cognitive impairment and the corresponding interventions that might prevent cognitive impairment as we age.

The influence of sex on limbic volume and perfusion in AD

The goal of the current study was to determine whether Alzheimer's disease (AD) pathology affects the limbic system of men and women differently as measured by in vivo neuroimaging. Magnetic resonance imaging (MRI) and coregistered single photon emission computed tomography (SPECT) were used to examine the limbic system in 20 men and 20 women with probable AD compared to 40 age- and education-matched normal controls (20 men, 20 women). Limbic volumes and relative perfusion values were obtained from the MR images and coregistered SPECT scans, respectively. No significant differences were found between sexes in limbic volumes or relative perfusion values in the normal controls. Many limbic regions were significantly affected in both men and women with AD compared to normal controls. However, only the men with AD displayed atrophy in the orbitofrontal cortex, middle and posterior cingulate cortices, hypothalamus, and mamillary bodies, and relative hypoperfusion in the anterior and middle cingulate cortices. Women with AD exclusively showed anterior thalamic atrophy. Separating men and women did not substantially improve diagnostic classification.

One year follow-up study of the association between chemical castration, sex hormones, beta-amyloid, memory and depression in men

The results of several recent studies suggest that estrogen and testosterone play an important role in the modulation of mood and cognitive function in women, and preliminary evidence indicates that these hormones may also modulate the levels of beta-amyloid (Abeta), a 4 Kilo Dalton peptide that is likely to be involved in the pathogenesis of Alzheimer's disease. However, the physiological and clinical effects of reversible castration remain unclear and no systematic data is currently available for men. We designed the present study to investigate the effects of reversible chemical castration on the mood and cognitive performance of men treated for prostate cancer, as well as its impact on the levels of plasma Abeta. Forty men with prostate cancer were clinically treated with androgen blockade therapy (flutamide and leuprolide) for 36 weeks and subsequently followed up for another 18 weeks after treatment was discontinued. All subjects received a comprehensive clinical, neuropsychological and biochemical evaluation that included the use of the Beck Depression (BDI) and Anxiety Inventories (BAI), several subtests of the Wechsler Memory and Intelligence Scales (Word Lists-WL, Verbal Paired Associates-VPA, Visual Reproduction-VR and Block Design-BD), and biochemical monitoring of changes in estrogen, testosterone and Abeta levels. Chemical castration was associated with a rapid and marked decline in the levels of testosterone and estradiol, and significant increase in plasma Abeta levels. Treatment was associated with increased BDI (p = 0.004) and BAI scores (p < 0.001), although such changes were of questionable clinical significance (i.e., few subjects had scores > or = 13). CAMCOG (p = 0.046) and WL recall total scores (p < 0.001) improved significantly after androgen blockade treatment was discontinued, but visuospatial abilities, as assessed by BD, was not influenced by the introduction or discontinuation of treatment. There was a significant negative correlation between changes in Abeta levels and subjects' WL total score change between weeks 36 and 54 (r = -0.452, p = 0.012). The results of this naturalistic study indicate that chemical castration is associated with a significant rise in the plasma levels of Abeta and, clinically, with increased depression and anxiety scores. The discontinuation of treatment is associated with better cognitive performance, most noticeably of verbal memory. The performance of subjects on the WL test was negatively correlated with plasma levels of Abeta, but the clinical significance of this finding remains to be determined.

Opposition to unpopular research results: Finnish professional reactions to the WHI findings

PURPOSE

Preventive hormone therapy (HT) has been popular. This article describes what happened, when unexpected results that speak against HT were published.

METHODS

The article describes what happened in Finland after a large US randomised study. Women's Health Initiative (WHI) showed preventive HT to be harmful. The data used in the present study came from statistics, surveys, participatory observations, and written material.

RESULTS

Use of HT increased in Finland in the 1990s, and long-term therapy became common. The opinions of Finnish physicians on HT were positive. After the WHI results were published in July 2002, they received wide publicity, and recommendations to reduce HT use were made in the United States. In Finland, the initial critical comments on HT were soon replaced by criticism of the WHI study in both the professional and the lay press. The criticism concerned the type of the drug used (not used in Finland), the population ("not healthy, too old"), and outcome measures; the results were said not to apply to Finland. The value of a trial in contrast to the non-experimental evidence was rarely stressed. Odd information supplied and the uniformity of the formulations used by gynaecologists and medical journalists suggested that these professionals had been trained by the drug firms preparing competing HT drugs.

CONCLUSIONS

This case shows that when a well-done trial results in a negative assessment of a widely used drug, those benefiting from its continued use may aggressively resist, even despite weak evidence for their position.

Perimenopausal and Postmenopausal Health

HEALTH ISSUE: The average age of natural menopause in Western societies is estimated to be 51 years; women in Canada can therefore expect to live, on average, a third of their lives in post-menopausal years. During these years women are at increased risk of chronic diseases such as osteoporosis and cardiovascular disease. KEY FINDINGS: Clinical and epidemiological data on women in perimenopause are limited. There are no adequate Canadian data on symptom severity and prevalence among perimenopausal and postmenopausal women. Scientific evidence is lacking to support or refute claims that commonly used botanical products can offer therapeutic relief of menopausal symptoms.Recent data from the Women's Health Initiative suggest that combined estrogen plus therapy increases the risk of stroke, coronary artery disease and breast cancer. Hormone therapy is no longer recommended for the prevention of chronic diseases for asymptomatic women. Stroke is an important issue for perimenopausal and postmenopausal women and sex differences may exist in the progestin treatment of stroke. Osteoporosis affects an estimated one in six women over the age of 50. DATA GAPS AND RECOMMENDATIONS: There is a need to conduct clinical and epidemiological research aimed at better understanding the menopausal transition and defining its clinical phases. Investigations aimed at alternative combinations and doses of hormone therapy and non-pharmaceutical alternatives in light of known risks and benefits are also necessary. Health care practitioners and women need to be educated on the risks and effective treatment related to cardiovascular disease so they can present for treatment more quickly and receive the most effective therapies.

Hormone replacement therapy update: who should we be prescribing this to now?

PURPOSE OF REVIEW

To summarize results from the Women's Health Initiative trial and other recent randomized placebo-controlled trials of hormone replacement therapy, which fundamentally changed our understanding of its risks and benefits.

RECENT FINDINGS

The Women's Health Initiative study for the first time provided evidence of harmful effects of hormone replacement therapy on the cardiovascular system and also confirmed significantly increased risk of breast cancer which was previously documented in a metaanalysis. Most recent studies indicate a particularly harmful effect of combined estrogen/progestin regimens in terms of increased breast cancer risk.

SUMMARY

The effects of hormone replacement therapy on coronary heart disease, stroke, venous thromboembolism, breast cancer, gallbladder, diabetes, cognitive function, health-related quality of life, colorectal cancer, osteoporosis and menopausal symptoms are discussed briefly. The emphasis is on providing concise clinical guidelines for hormone replacement therapy use in new circumstances. We also discuss some alternative therapeutic modalities for women who have menopausal symptoms, but contraindications for hormone replacement therapy.

Is the WHI relevant to HRT started in the perimenopause?

The Women's Health Initiative (WHI) hormone replacement therapy (HRT) estrogen plus progestin (E+P) and estrogen-only arms are part of a large NIH-sponsored randomized controlled trial (RCT). Both arms were terminated prematurely after 5 and 8 yr, respectively. The E+P arm showed non-statistically significant increased incidences of cardiovascular events and breast cancer, whereas the E-only arm did not. Both arms showed an increased rate of thromboembolic events and stroke. Both arms showed protection against fractures and with protection against colon cancer only in the E+P arm. These results have been widely generalized as indicating a negative risk/benefit ratio for HRT in menopausal women. The WHI results are at odds with results of large epidemiological studies that showed protection against cardiovascular disease. Although the latter data are, in part, confounded by a "healthy user bias," much of the inconsistency may be explained by the fact that women in the latter studies initiated HRT at the menopausal transition, whereas the WHI trial was conducted in older women (mean age 63.3), who were, on average, approx 12 yr postmenopausal. In addition, older trials included women on either unopposed estrogen therapy (ERT) or cyclic HRT regimens. Whatever other forces may have been at work, observational and experimental evidence supports the conclusion that estrogen's atheropreventive effects predominate early, in the absence of vulnerable plaque to be ruptured or thrombotic episodes propagated by narrowed lumens and intravascular turbulence. On the contrary, age-related adverse effects of HRT may prevail once complex atheromas and luminal narrowing/irregularity are established. It is known that prevalence of subclinical "at-risk" atherosclerotic lesions increases in women during the first 5-10 yr after menopause. Furthermore, animal and clinical evidence supports the use of lower doses of estrogen than were employed in the WHI in older/longer postmenopausal women.

Cognition, mood disorders, and sex hormones

Macaques (Macaca spp.) are useful models to evaluate effects of ovarian sex steroids and selective estrogen receptor modulators (SERMs) on mood and cognitive function due to similarities to women in their reproductive and central nervous systems. The results of nonhuman primate studies support the hypothesis that estrogen mediates specific aspects of attention and memory, yet much work is needed to understand which cognitive processes are affected, whether natural versus surgical menopause effects are different, and the interaction of age and ovarian senescence on cognitive function. This knowledge is necessary to determine whether to support the cognitive function of women in the menopausal phase of life and, if so, to determine efficacious therapeutic interventions. Mood disorders are prevalent in women and are associated with reproductive function in women and macaques. Exogenous steroid therapies, including oral contraceptives and postmenopausal hormone replacement therapies, have behavioral effects in women and appear to affect the behavior and underlying neural substrates of monkeys. Additional research is necessary to confirm and extend these observations. Ovarian steroids have multiple effects on serotonin synthesis, reuptake, and degradation, on neural activity that drives serotonin release, and on receptor activation in primates. This system modulates cognitive function and mood and is the target of a broad class of antidepressant therapies. Understanding the effects of ovarian steroids on the neural serotonergic system is necessary to understand depression in women. These studies are best carried out in primate models, which are more similar to humans in neural serotonergic function than other animal models.

Impact of estrogen therapy on Alzheimer's disease: a fork in the road?

The results of recent clinical studies have challenged our previously held view that estrogen therapy promotes neurological health and prevents or ameliorates Alzheimer's disease. A major question emerging from these studies is: how can there be such disparity between the basic science and epidemiological data that show that estrogen can protect neurons against degenerative insults and reduce the risk of Alzheimer's disease and the recent data (from the Women's Health Initiative Memory Study [WHIMS] trial and the trial of estrogen treatment for Alzheimer's disease), which show that hormone replacement therapy (HRT) showed no benefit and even a potential deleterious effect? Which set of data is correct? The proposition put forth in this review is that both sets of data are correct and that two major factors determine the efficacy of estrogen or HRT. First is the time at which estrogen therapy is initiated. The data indicate that initiation of therapy early in menopause and when neurons are in a healthy state, reduces the risk of Alzheimer's disease; whereas, estrogen therapy initiated after the disease has developed or decades following menopause is without benefit. Second, estrogen therapy is not the same as HRT and the type of progestogen used determines the outcome of the therapeutic intervention. Insights into the mechanisms of action of estrogen and progestogen in the brain provide a framework for understanding the paradox of the benefit of estrogen in the prevention of Alzheimer's disease versus the lack of benefit in treatment trials and in trials when HRT is instituted many years after menopause. Based on estrogen-inducible mechanisms, which have been elucidated in healthy neuron model systems, it would be predicted that estrogen therapy could be highly effective in preventing neurodegenerative disease by promoting neuronal defence and memory mechanisms. The mechanisms of action of estrogen also predict that estrogen therapy would be an ineffective strategy for reversing the pathology of Alzheimer's disease. In summary, the time at which estrogen therapy is initiated, the neurological status of the brain at the time of estrogen therapy initiation and the type of progestogen used all contribute to the efficacy of estrogen in preventing neurodegenerative disease and to sustaining neurological health and function. An estrogen advantage hypothesis is put forth that provides a unifying mechanism of estrogen action with implications for both the benefits and risks of estrogen therapy.

Estrogen facilitates neurite extension via apolipoprotein E in cultured adult mouse cortical neurons

Literature review suggests a close relationship between estrogen and apolipoprotein E (ApoE) in the central nervous system. Epidemiology studies show that estrogen replacement therapy (ERT) decreases the morbidity from several chronic neurological diseases. Alleles of ApoE modify the risk for and progression of the same diseases. ApoE levels in the rodent brain vary during the estrous cycle and increase after 17beta-estradiol administration. Both estradiol and ApoE3, the most common isoform of human ApoE, increase the extent of neurite outgrowth in culture. Combined, these observations suggest a common mechanism whereby estrogen may increase ApoE levels to facilitate neurite growth. We tested this hypothesis by characterizing the effects of estradiol and ApoE isoforms on neurite outgrowth in cultured adult mouse cortical neurons. Estradiol increased ApoE levels and neurite outgrowth. ApoE2 increased neurite length more so than ApoE3 in the presence of estradiol. Estradiol had no effect on neurite outgrowth from mice lacking the ApoE gene or when only ApoE4, the isoform of ApoE that is associated with increased risk of neurological disease, was exogenously supplied. Cultures from mice transgenic for human ApoE3 or ApoE4 showed the same isoform-specific effect. Neuronal internalization of recombinant human ApoE3 was greater than ApoE4, and ApoE3 was more effective than ApoE4 in facilitating neuronal uptake of a fatty acid. We conclude that estradiol facilitates neurite growth through an ApoE-dependent mechanism. The effects of ERT on chronic neurological diseases may vary with ApoE genotype. The clinical use of ERT may require ApoE genotyping for optimal efficacy.

A randomized, placebo-controlled, crossover study of tibolone (Livial) on menopause symptoms, psychological well-being, and dyadic relationship of postmenopausal Chinese women and their spouses

OBJECTIVE

To investigate the effects of 6-month treatment of tibolone on menopause symptoms, psychological well-being, and the dyadic relationship of postmenopausal Chinese women and their spouses.

DESIGN

A randomized, double-blind, crossover study was conducted in 100 postmenopausal Hong Kong Chinese women who received tibolone (2.5mg/day) and placebo. At baseline, 6-month and 13-month visits, the women filled in the Greene Climacteric Scale (GCS), 12-item General Health Questionnaire (GHQ) and Dyadic Adjustment Scale (DAS), and their spouses completed GHQ and DAS.

RESULTS

Both tibolone and placebo treatment were associated with a significant reduction in the GCS total scores after the first 6-month interventional period (95% CI: -8.0 to -2.5 for tibolone, and -5.7 to -0.7 for placebo). After the correction for placebo response, tibolone treatment was associated with a significant reduction in the GCS somatic subscore (-1.1 +/- 0.4 for tibolone group versus 0.6 +/- 0.5 for placebo group, P < 0.05). There were no significant changes in the GHQ and DAS total scores of the women and their spouses after tibolone treatment, both with and without the correction for placebo response.

CONCLUSIONS

Tibolone treatment had a significant beneficial effect on the somatic menopause symptoms but had no effect on the psychological well-being or marital relationship of the postmenopausal Chinese women and their spouses.

Can dementia be prevented? Brain aging in a population-based context

As a consequence of global aging of the human population, the occurrence of cognitive impairment and dementia is rapidly becoming a significant burden for medical care and public health systems. By the year 2020, the WHO predicts there will be nearly 29 million demented people in both developed and developing countries. Primary and secondary prevention of dementia through individual and population-level interventions could reduce this imminent risk. Vascular risk factors such as type 2 diabetes, hypertension, dietary fat intake, high cholesterol, and obesity have emerged as important influences on the risk of both vascular and Alzheimer's dementia. Understanding the reasons for differences between populations in genetic vulnerability and environmental exposures may help to identify modifiable risk factors that may lead to effective prevention of vascular and Alzheimer's dementia.

Local synthesis and dual actions of progesterone in the nervous system: neuroprotection and myelination

Progesterone (PROG) is synthesized in the brain, spinal cord and peripheral nerves. Its direct precursor pregnenolone is either derived from the circulation or from local de novo synthesis as cytochrome P450scc, which converts cholesterol to pregnenolone, is expressed in the nervous system. Pregnenolone is converted to PROG by 3beta-hydroxysteroid dehydrogenase (3beta-HSD). In situ hybridization studies have shown that this enzyme is expressed throughout the rat brain, spinal cord and dorsal root ganglia (DRG) mainly by neurons. Macroglial cells, including astrocytes, oligodendroglial cells and Schwann cells, also have the capacity to synthesize PROG, but expression and activity of 3beta-HSD in these cells are regulated by cellular interactions. Thus, Schwann cells convert pregnenolone to PROG in response to a neuronal signal. There is now strong evidence that P450scc and 3beta-HSD are expressed in the human nervous system, where PROG synthesis also takes place. Although there are only a few studies addressing the biological significance of PROG synthesis in the brain, the autocrine/paracrine actions of locally synthesized PROG are likely to play an important role in the viability of neurons and in the formation of myelin sheaths. The neuroprotective effects of PROG have recently been documented in a murine model of spinal cord motoneuron degeneration, the Wobbler mouse. The treatment of symptomatic Wobbler mice with PROG for 15 days attenuated the neuropathological changes in spinal motoneurons and had beneficial effects on muscle strength and the survival rate of the animals. PROG may exert its neuroprotective effects by regulating expression of specific genes in neurons and glial cells, which may become hormone-sensitive after injury. The promyelinating effects of PROG were first documented in the mouse sciatic nerve and in co-cultures of sensory neurons and Schwann cells. PROG also promotes myelination in the brain, as shown in vitro in explant cultures of cerebellar slices and in vivo in the cerebellar peduncle of aged rats after toxin-induced demyelination. Local synthesis of PROG in the brain and the neuroprotective and promyelinating effects of this neurosteroid offer interesting therapeutic possibilities for the prevention and treatment of neurodegenerative diseases, for accelerating regenerative processes and for preserving cognitive functions during aging.

[Hormone therapy in menopause. A current update]

While the use of hormone replacement therapy (HRT) for prophylactic indications such as cardiovascular disease, osteoporosis, and Alzheimer's disease was increasingly propagated during the 1990s, recent studies have reported no risk reduction for women after myocardial infarction (HERS) or women from a mixed population with an average age of 63 years (Women's Health Initiative [WHI] Study). The results of the latter study even suggest an increased risk for cardiovascular events and breast cancer with previous or ongoing combined oral estrogen plus progestin. A final risk-benefit assessment for estrogen monotherapy will only be possible after the ongoing part of the WHI Study has been evaluated, expected in 2005. As effects, side effects, and contraindications for HRT in postmenopausal women are better known, the need for individualized risk assessment and the definition of therapeutic goals increases. Since the WHI Study did not address the risk-benefit ratio for women with perimenopausal complaints or osteoporosis or with lower dose hormone preparations commonly used in Germany, there is an urgent need to answer these open questions with large confirmative studies.

Normal genetic variation, cognition, and aging

This article reviews the modulation of cognitive function by normal genetic variation. Although the heritability of "g" is well established, the genes that modulate specific cognitive functions are largely unidentified. Application of the allelic association approach to individual differences in cognition has begun to reveal the effects of single nucleotide polymorphisms on specific and general cognitive functions. This article proposes a framework for relating genotype to cognitive phenotype by considering the effect of genetic variation on the protein product of specific genes within the context of the neural basis of particular cognitive domains. Specificity of effects is considered, from genes controlling part of one receptor type to genes controlling agents of neuronal repair, and evidence is reviewed of cognitive modulation by polymorphisms in dopaminergic and cholinergic receptor genes, dopaminergic enzyme genes, and neurotrophic genes. Although allelic variation in certain genes can be reliably linked to cognition--specifically to components of attention, working memory, and executive function in healthy adults--the specificity, generality, and replicability of the effects are not fully known.

Les alternatives au traitement hormonal substitutif de la ménopause : le point épidémiologique

OBJECTIVE

Recent results put into question the risks/benefits ratio of hormone replacement therapy and emphasize the importance of precise knowledge of the effects of other treatments that exist for postmenopausal symptoms or diseases. Our aim is to analyze their effect.

METHODS

A review of randomized trials or epidemiological studies was undertaken.

RESULTS

Bisphophonates, calcitonin, parathormone, strontium ranelate, calcium and vitamin D have specific effects on bone. The efficacy of bisphophonates for prevention and treatment of osteoporosis has been proven and parathormone and strontium ranelate seem promising. These treatments are useful for women at high risk of osteoporosis who do not suffer from menopausal symptoms. Tibolone, SERMs and phytoestrogens exert effects on various tissues. SERMs are very promising, but they do not improve climacteric symptoms and their long term effects are still unknown. Tibolone has beneficial effects on climacteric symptoms and on bone loss, but recent results concerning its effects on the risk of breast cancer call into question its interest. The beneficial effects of phytoestrogens on bone and on vasomotor symptoms need to be confirmed.

CONCLUSION

At this time, none of the existing treatments for postmenopausal symptoms or diseases is ideal. The existence of several options for treatments of symptoms or diseases of the postmenopause is helpful as it affords several choices for physicians and for women who sometimes need to be treated for many years. However several questions remain unanswered concerning the long term effects of these treatments.

Hormonal fountains of youth

Any hope of a fountain of youth to stop people from getting older is a long way off, with science just beginning to understand the complex genetic, physical, and hormonal causes of aging. Clearly, modem research has demonstrated that the concept of a hormonal fountain of youth is predominantly mythology. The best evidence supporting use of hormonal replacement is vitamin D and estrogen replacement to prevent hip fractures. Other than that, treatment should be limited to hormone replacement in persons who have endocrine disease.

A comparative review of the risks and benefits of hormone replacement therapy regimens

The Women's Health Initiative (a large, randomized, placebo-controlled trial) investigated the effect of conjugated equine estrogens combined with medroxyprogesterone acetate on specific potential long-term benefits and risks. A review of the clinical studies that have investigated different types and regimens of estrogens combined with progestins was conducted to assess how applicable the results of the Women's Health Initiative are to hormone replacement therapy regimens in general. The studies that were reviewed were limited to randomized clinical trials and observational studies that have been published over the last 15 years (1987-2002) and to meta-analyses and reviews that may have included the literature before 1987. The increased risks for venous thromboembolism, stroke, coronary heart disease, and breast cancer that were identified in the Women's Health Initiative trial have also been reported with postmenopausal hormone therapies that contain a variety of estrogen and progestin products. The beneficial effects that were noted in the Women's Health Initiative, with respect to reductions in fractures and colorectal cancer, have not been evaluated in large, randomized controlled trials that use different estrogen/progestin combinations; however, observational trials that used a variety of estrogen or hormone replacement therapy products and randomized clinical studies that evaluated bone mineral density (an excellent predictor of fracture risk) with different estrogen/hormone replacement therapy regimens would suggest that results would be similar to those found in the Women's Health Initiative. Although the relief of menopausal symptoms, the primary reason women seek treatment, was not included in the overall benefit/risk analysis of the Women's Health Initiative, numerous trials suggest that all therapies are effective. Overall, these data indicate that the benefit/risk analysis that was reported in the Women's Health Initiative can be generalized to all postmenopausal hormone replacement therapy products.

Risk factors for coronary heart disease in women

The increased focus on risk factors for CHD in women has greatly improved our understanding of this disease in women. The evidence against cigarette smoking, elevated serum cholesterol, and high blood pressure is strong, and sustained campaigns are underway to prevent and appropriately manage these conditions. The importance of adequate physical activity and weight control is well established, and research continues on other emerging risk factors. The focus of future research will be on clarifying the role of these factors, particularly for women and ethnic minorities.

Perimenopause: an update

The field of perimenopause research is advancing our understanding of the physiological changes related to the menopausal transition and approaches to managing symptoms and preventing disease of advanced age. The impact of the perimenopause on women's health will become evident with the aging of the population.

Exercise and Estrogen or Estrogen Alternatives (Phytoestrogens, Bisphosphonates) for Preservation of Bone Mineral in Postmenopausal Women

Research in animal models indicates that without estrogen, the effectiveness of exercise for increasing bone mineral in females is reduced. With decreased estrogen levels, there is an increase in the threshold at which strains are detected by bone, in turn reducing the transmission of mechanical to biochemical signals for bone formation. Studies combining estrogen replacement and exercise training in postmenopausal women have yielded mixed results but indicate that the combination of interventions may be more effective than either intervention alone for increasing bone mass. Given the continued debate over the risks and benefits of estrogen replacement, other compounds such as bisphosphonates or phytoestrogens may be preferred in combination with exercise training for optimally increasing bone mass and preventing osteoporotic fracture. Studies on animals show that the combination of bisphosphonate or phytoestrogen supplementation with exercise training is effective, but trials in humans are lacking. Key words: osteoporosis, hormone replacement therapy, bisphosphonates, phytoestrogens, isoflavones

Evidence that androgenic and estrogenic metabolites contribute to the effects of dehydroepiandrosterone on cognition in postmenopausal women

Prior studies of the effects of dehydroepiandrosterone (DHEA) on cognition have produced complex and inconsistent results. We hypothesize that these results may arise, in part, because of DHEA's metabolism into estrogens and androgens that produce opposing effects on cognition. Our study administered 50 mg of oral DHEA daily for 4 weeks in a placebo-controlled crossover design to six postmenopausal women. We measured blood levels of androgens (total testosterone, free testosterone, DHEA, DHEAS), estrogens (estradiol, estrone), and cognitive performance on recognition memory, perceptual identification, digit span memory, and visual attentional vigilance under both drug and placebo conditions. Multiple regression models incorporating the factors of age and body mass index (BMI) were used to ascertain the relation between sex steroids and cognitive performance. Our results demonstrated that estrogens produced a positive effect on recognition memory, while androgens produced a negative effect. This pattern reversed in perceptual identification with estrogens producing a negative effect and androgens producing a positive effect. In addition, BMI produced a negative effect on digit span memory, age produced a negative effect on perceptual identification, and androgens produced a negative effect on visual attentional vigilance. These results help, in part, to explain DHEA's complex effects on cognition. The diverse effects of sex steroids across tasks underscore the importance of identifying the specific cognitive mechanisms influenced by sex steroids and emphasizes that one should not expect sex steroids to produce homogeneous effects across cognitive tasks.

Practical measurement of total and bioavailable estradiol in female macaques

BACKGROUND

Commercially available, direct assay kits provide a simple and rapid means for measuring estradiol. Similarly, ammonium sulfate precipitation of SHBG-bound steroids is a reliable alternative to equilibrium dialysis or ultrafiltration for assessing bioavailability. However, while these techniques are useful for humans, they have yet to be evaluated systematically for macaques-species which are frequently used to model estrogen effects on women's health.

METHODS

A reference assay (which included chromatography) and two modified versions of a human kit (one in which monkey serum was assayed directly, and another in which an extraction step was added) were used to measure estradiol in matching samples. Ammonium sulfate precipitation and an established ultrafiltration technique were used to assess bioavailability.

RESULTS

Values from both kit modifications correlated significantly with those from the reference assay. Although both modifications underestimated values, the addition of the extraction step resulted in far more useful estimates due to the consistency of underestimation across the standard curve. Measures of bioavailability from ammonium sulfate precipitation and ultrafiltration were strongly correlated and consistent across all concentrations.

CONCLUSIONS

Simplified techniques developed for humans can be used in macaques, although the addition of an extraction step markedly improves the performance of direct assay kits.

Median raphe mediates estrogenic effects to the hippocampus in female rats

Subcortical regions such as the medial septum-diagonal band of Broca and supramammillary area have been shown to mediate indirect oestrogenic effects on hippocampal morphology and function. Here, the role of the median raphe (MR), a serotonergic subcortical structure, is studied. To this end, 17beta-estradiol-filled 30-gauge cannulae were implanted into the MR of female ovariectomized rats; cholesterol-filled cannulae served as controls. After seven days, using unbiased electron microscopic stereological calculations and semiquantitative analysis, the spine synapse density and surface density of glial fibrillary acidic protein-positive astrocyte processes, respectively, were determined in the stratum radiatum of the CA1 region of the hippocampus. Changes in the serotonergic innervation of the hippocampal CA1 region were determined by immunohistochemistry and subsequent morphometric analysis. In the stratum radiatum of the CA1 region, local estradiol application into the MR resulted in a 47% increase in spine synapse density. Simultaneously, the density of glial fibrillary acidic protein-positive fibers decreased by 16%. The density of serotonin (5-HT) innervation of the strata lacunosum moleculare and radiatum of the CA1 region of the hippocampus was reduced in response to estradiol, as shown by a decrease in the length of fibers (27.6 and 48.3% decrease, respectively) and the number of large varicosities (32.5 and 38.8% decrease, respectively). These observations suggest a major role of the MR in mediating oestrogenic effects on the hippocampus and an involvement of the serotonergic system.

Regulation of cytokine-induced neuron death by ovarian hormones: involvement of antiapoptotic protein expression and c-JUN N-terminal kinase-mediated proapoptotic signaling

Mechanisms underlying the divergent effects of ovarian hormones on neuron death induced by TNFalpha were investigated in differentiated PC12 cells (dPC12). dPC12 cells were exposed to 17beta-estradiol (E, 1.0 nm), progesterone (P, 100 nm), or a combination of both hormones for 0-72 h before treatment with TNFalpha (0-150 ng) to induce cell death. Cells undergoing apoptosis were identified by a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay and fluorescence-activated cell sorting after 18 h. Cell death induced by TNFalpha was decreased 89% after E treatment and increased 2-fold after P treatment compared with cells treated with TNFalpha alone. Treatment with E for 24 h before TNFalpha exposure was required for maximum neuroprotection, whereas P-enhanced death was maximal after a 30-min P treatment. TNFalpha induced a 3-fold increased activity of c-JUN-N-terminal kinase (JNK) 1 in d PC12 cells within 20 min that could be increased 5- to 8-fold by P together with TNFalpha. A peptide inhibitor of JNK1 abrogated P enhancement of TNFalpha-mediated dPC12 death but had only a minimal effect on cell death by TNFalpha alone. Inhibition of caspase-8 activation reduced death induced by TNFalpha alone but was much less effective for P+TNF. P alone did not activate caspase-8. E increased estrogen receptor alpha (ERalpha) and Bcl-xL expression and all but abolished TNFalpha receptor 1 (TNFR1) expression. P decreased ERalpha and Bcl-xL expression and doubled TNFR1 expression. These data suggest that P regulates apoptosis or survival through augmentation of JNK signaling and altered TNFR1 expression, whereas E mainly affects the expression of BCL-xL, TNFR1, and ERalpha.

Menopausal hormone therapy: Is there evidence for cardiac protection?

Menopausal hormone therapy currently has no evidence-based role in the primary or secondary prevention of cardiovascular disease in women. Repeat analysis of the observational data that corrected for socioeconomic status, educational level, and coronary risk factors; as well as information from randomized clinical trials of menopausal hormone therapy both for healthy women and for women with established coronary heart disease and stroke support this statement. This approach is corroborated by recommendations from the US Food and Drug Administration and the recently released Guidelines for Cardiovascular Prevention for Women of the American Heart Association. The latter Guidelines display the lifestyle and pharmacologic interventions that are appropriate for cardiovascular disease risk reduction for women.

Effects of estrogen replacement therapy on cholinergic basal forebrain neurons and cortical cholinergic innervation in young and aged ovariectomized rhesus monkeys

Estrogen modulates the function of cholinergic basal forebrain neurons in aged female rats. The present study tested the hypothesis that estrogen enhances the phenotype of cholinergic basal forebrain neurons and their cortical cholinergic innervation in young adult and aged ovariectomized rhesus monkeys. Sixteen monkeys (9 young and 7 aged) received two injections of estradiol cypionate or vehicle separated by 3 weeks. All monkeys were killed 1 day after the last injection. Quantitative immunofluorescence in the vertical limb of the diagonal band (VLDB) revealed enhanced optical density for choline acetyltransferase (ChAT) in both young and aged monkeys treated with estrogen. In contrast, optical density for low-affinity p75 neurotrophin receptor immunoreactivity in the VLDB did not change after estrogen treatment in either aged or young animals. Quantitative immunofluorescence for either ChAT or the low-affinity p75 neurotrophin receptor in the nucleus basalis Meynert failed to reveal differences between vehicle and estrogen treatment in either age group. Quantitative estimates of acetylcholinesterase (AChE) fiber density revealed that estrogen-treated aged monkeys but not their younger counterparts had decreased numbers of AChE-positive fibers in layer II of frontal, insular, and cingulate cortices. These data indicate that estrogen administered in a manner simulating natural hormonal cyclicity produces modest age-specific chemical phenotypic and regional changes in select neuronal subfields of the cholinergic basal forebrain and their cortical projection sites in nonhuman primates.

Impact of the selective estrogen receptor modulator, raloxifene, on neuronal survival and outgrowth following toxic insults associated with aging and Alzheimer's disease

The current study investigated the estrogen agonist-antagonist properties of the selective estrogen receptor modulator, raloxifene (Ral), on neuroprotection and neuronal markers of memory function. Low concentrations of raloxifene significantly reduced basal markers of membrane damage and had no deleterious effect on neuronal survival. However, high concentrations of raloxifene (1000-5000 ng/ml) induced a significant increase in markers of membrane damage and a significant decrease in neuronal survival. At subtoxic concentrations, raloxifene induced significant neuroprotection against beta amyloid(25-35)-, hydrogen peroxide- and glutamate-induced toxicity. Results of analyses to determine whether raloxifene acted competitively or synergistically with 17 beta-estradiol revealed that a postmenopausal level of 17 beta-estradiol exerted a significantly greater increase in neuronal survival against beta-amyloid- and glutamate-induced toxicity compared to 50 ng/ml raloxifene. The combined presence of raloxifene and 17 beta-estradiol was significantly neuroprotective against beta amyloid(25-35)- and glutamate-induced excitotoxicity but was significantly lower than 17 beta-estradiol alone while not significantly different than raloxifene alone. Morphologic analyses demonstrated that raloxifene significantly increased neuronal outgrowth of hippocampal neurons within a narrow dose range that was blocked by a glutamate NMDA receptor antagonist. Raloxifene did not promote the outgrowth of basal forebrain or cortical neurons. Results of this study indicate that raloxifene exerted partial estrogen agonist action in the absence of 17 beta-estradiol whereas in the presence of 17 beta-estradiol, raloxifene exerted a mixed estrogen agonist-antagonist effect.

Molecular Mechanisms, Physiological Consequences and Pharmacological Implications of Estrogen Receptor Action

The estrogen receptors (ERs), ERalpha and ERbeta, play a central role in mediating the biological effects of estrogen. The transcription rate of estrogen target genes is determined by several parameters including the type of ligand, estrogen receptor subtype and isoform, as well as interactions with receptor-binding cofactor proteins. The ERs regulate gene expression by binding to specific response element sequences in the promoters of estrogen target genes. Alternative pathways have also been described in which the ERs modulate transcription indirectly, via protein : protein interactions. In this regulatory mode, which has been traced to activator protein (AP)-1-, cyclic adenosine monophosphate (cAMP)-, and Sp1-response elements, the ERs appear to be tethered to target gene promoters via heterologous transcription factors. It has been found that ERalpha and ERbeta have opposite effects on transcription mediated via the indirect mode of action. Moreover, recent studies suggest that ERbeta may inhibit the stimulatory effects of ERalpha on cellular proliferation. Estrogen is a key regulatory hormone that affects numerous physiological processes. Estrogen is required for female pubertal development and affects growth, differentiation and function of the female reproductive system. It has recently been suggested that estrogen also has an important role in the male urogenital tract. In addition, estrogens have profound effects in other tissues. For instance, in the skeleton estrogen prevents bone-resorption by inhibition of osteoclast function. Numerous reports have suggested that estrogen has a beneficial effect in the cardiovascular system and in the CNS; however, this has not been confirmed in randomized clinical trials. In fact, a large randomized trial on healthy postmenopausal women receiving oral estrogen plus progestin showed an increased incidence of cardiovascular disease. In addition, this study revealed an increased risk for dementia and impaired cognitive function in the group receiving oral estrogen/progestin. Additional clinical trials are required to determine which hormonal component causes these health risks or whether the effects were due to the combination of estrogen and progestin.

Alternative hormone replacement regimens: is there a need for further clinical trials?

PURPOSE OF REVIEW

To review the randomized trials of hormone replacement therapy.

RECENT FINDINGS

Studies have shown that conjugated equine estrogen 0.625 mg a day plus medroxyprogesterone acetate 2.5 mg a day increased the risk of cardiovascular events during the first year of treatment in women both with and without coronary heart disease. Conjugated equine estrogen plus medroxyprogesterone acetate also increased the overall risk of myocardial infarction and stroke in women without coronary heart disease, and myocardial infarction or death in women with coronary heart disease, and also increased the risk of breast cancer, cognitive decline and dementia. Unopposed, oral 17B-estradiol increased the risk of stroke during the first 6 months of treatment in women with a previous stroke. Oral 17B-estradiol with or without cyclic progestin had no effect on the progression of atherosclerosis or reinfarction. Transdermal 17B-estradiol plus cyclic progestin was associated with a non-significant increase in coronary heart disease events in women with coronary heart disease. Compared with placebo, cardiovascular events increased in the ongoing estrogen-only arm of the Women's Health Initiative, indicating that unopposed conjugated equine estrogen is unlikely to be cardioprotective. However, oral 17B-estradiol retarded the progression of subclinical atherosclerosis in younger women without coronary heart disease.

SUMMARY

Hormone replacement therapy should not be initiated for the primary or secondary prevention of coronary heart disease in women. A trial of 17B-estradiol started at menopause in women without coronary heart disease should be considered.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

Double-blind, randomized placebo-controlled trial.

PATIENTS

Fifty women with type 2 diabetes.

MEASUREMENTS

Classical and novel risk factors for vascular disease.

RESULTS

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

CONCLUSIONS

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

Postmenopausal hormone therapy: a concise guide to therapeutic uses, formulations, risks, and alternatives

Postmenopausal hormone replacement therapy is helpful in relieving menopausal vasomotor symptoms and vaginal atrophy and can prevent osteoporosis; however, attendant risks include breast cancer, thromboembolism, gallbladder disease, stroke, CHD, dementia, and hypertriglyceridemia. Decision making must weigh these risks and benefits and also include potential benefits on mood, colorectal cancer prevention, and hip fracture reduction. Some areas, such as ovarian cancer risk and the impact of combination estrogen-progestin versus unopposed estrogen on risk, remain unclear. The physician and patient need to carefully assess, discuss, and monitor the individual's symptoms and risks when considering HT use. For those with contraindications or concerns about HT, there are alternative therapies of variable efficacy for vasomotor symptoms and vaginal atrophy.

The impact of adjuvant therapy for breast cancer on cognitive function: current evidence and directions for research

Available evidence supports the hypothesis that adjuvant chemotherapy for breast cancer can produce cognitive deficits, and that these deficits may have a significant impact on patients' quality of life. Studies have generally compared the results of a variety of cognitive measures performed following treatment to standardized population-based norms or to cancer patients who received local therapy, rather than to the individual's baseline level of functioning. Several longitudinal studies are in progress or in the planning stages to better quantify and understand the incidence and impact of cognitive effects of adjuvant chemotherapy, and to identify possible susceptibility factors in subgroups. Although the neurocognitive changes appear to be subtle, there may be enough data to consider discussing the possibility of cognitive dysfunction as an adverse effect when assessing the risks and benefits of adjuvant chemotherapy. Likewise, as the aromatase inhibitors are increasingly given to larger numbers of women in the adjuvant setting, it will be important to understand the cognitive impact of estrogen deprivation. Finally, there is interest in examining supportive pharmacologic or behavioral measures that might prevent or decrease cognitive effects in this setting. Herein, the data on cognitive changes associated with chemotherapy for breast cancer, current and future research directions, as well as possible treatments are reviewed.