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

Neurologic complications of nondiabetic endocrine disorders

PURPOSE OF REVIEW

This article provides an overview of the neurologic complications found in the various endocrine disorders affecting adult patients. Specifically, disorders in pituitary hormones (prolactin, growth hormone, vasopressin, and oxytocin), thyroid hormones, adrenal hormones (glucocorticoids), and sex hormones (estrogen and testosterone) will be covered, with an emphasis on identifying the signs and symptoms in addition to diagnosing and managing these disorders.

RECENT FINDINGS

Hyperthyroidism in the young was found to increase the risk for ischemic stroke in a recent prospective case-cohort study. The cognitive effects of hormonal therapy in postmenopausal women remain controversial, but a recent study found no benefit or risk in cognitive function when treating younger (50 to 55 years of age) postmenopausal women with hormonal therapy.

SUMMARY

Endocrine disorders can cause various neurologic complications, from insidious myopathy to acute encephalopathy. Diagnosing the endocrine disorder as the cause of the neurologic impairment is essential, as treating the underlying hormonal dysfunction will often rapidly reverse the neurologic symptoms. Ongoing research is needed to further clarify the role of hormonal dysfunction in neurologic disorders.

Oophorectomy, estrogen, and dementia: a 2014 update

Current evidence suggests that estrogen may have beneficial, neutral, or detrimental effects on the brain depending on age, type of menopause (natural versus induced), or stage of menopause (early versus late), consistent with the timing hypothesis. Three studies have now compared women who underwent bilateral oophorectomy before menopause with referent women and consistently showed an increased risk of cognitive decline and dementia. These studies suggest a sizeable neuroprotective effect of estrogen naturally produced by the ovaries before age 50 years. In this article, we focus on neuroprotection as related to cognitive decline and dementia. Several case-control studies and cohort studies also showed neuroprotective effects in women who received estrogen treatment (ET) in the early postmenopausal stage (most commonly at ages 50-60 years). The majority of women in those observational studies had undergone natural menopause and were treated for the relief of menopausal symptoms. However, the clinical trials by the Women's Health Initiative showed that women who initiated ET alone or in combination with a progestin in the late postmenopausal stage (ages 65-79 years) experienced an increased risk of dementia and cognitive decline regardless of the type of menopause. Three observational studies have now formally tested the timing hypothesis, and showed that the neuroprotective or harmful effects of estrogen depend on age at the time of initiation of treatment and on stage of menopause. Therefore, women who undergo bilateral oophorectomy before the onset of menopause or women who experience premature or early natural menopause should be considered for hormonal treatment until the average age of natural menopause (around age 50 years). Recommendations for the use of ET by women who experience natural menopause at typical ages remain less certain, and more research is needed.

Impact of a premature menopause on cognitive function in later life

OBJECTIVE

To determine whether premature menopause (≤40 years) can have long-lasting effects on later-life cognition and investigate whether this association varies depending on the type of menopause and use of hormone treatment (HT).

DESIGN

Population-based cohort study.

SETTING

The French Three-City Study.

POPULATION

Four thousand eight hundred and sixty-eight women aged at least 65 years.

METHODS

Multivariable-adjusted logistic regression models were used to determine the association between age at menopause, type of menopause (surgical, natural), and the use of menopausal HT and later-life cognitive function.

MAIN OUTCOME MEASURES

Performance on a cognitive test battery (at baseline and over 7 years) and clinical dementia diagnosis.

RESULTS

Menopause at or before the age of 40 years, both premature bilateral ovariectomy and premature ovarian failure (non-surgical loss of ovarian function), was associated with worse verbal fluency (OR 1.56, 95%CI 1.12-1.87, P=0.004) and visual memory (OR 1.39, 95%CI 1.09-1.77, P=0.007) in later life. HT at the time of premature menopause appeared beneficial for later-life visual memory but increased the risk of poor verbal fluency. Type of menopause was not significantly associated with cognitive function. Premature menopause was associated with a 30% increased risk of decline in psychomotor speed and global cognitive function over 7 years.

CONCLUSION

Both premature surgical menopause and premature ovarian failure were associated with long-term negative effects on cognitive function, which are not entirely offset by menopausal HT. In terms of surgical menopause, these results suggest that the potential long-term effects on cognitive function should form part of the risk/benefit ratio when considering ovariectomy in younger women.

Estrogen receptor α polymorphisms and the risk of cognitive decline: A 2-year follow-up study

OBJECTIVE

The neuroprotective role of estrogen is supported by biochemical studies, but the results from clinical trials of estrogen replacement therapy on cognitive decline are controversial. One possible missing link might be the interindividual difference in estrogen receptor expression. In this study, the association of estrogen receptor α (ESR1) polymorphisms and cognitive decline was investigated.

METHODS

Chinese older adults (n = 284) were recruited, and the cognitive profile was follow-up over 2-year period. Twenty ESR1 polymorphisms were investigated and correlated with the cognitive decline for the subjects.

RESULTS

Significant association was found between ESR1 polymorphisms (rs9340799 [ESR1+351], rs1801132 [ESR1+975], rs6557171, rs9397456, and rs1884049) and subjects with no dementia (Clinical Dementia Rating, CDR 0) and very mild dementia (CDR 0.5). Several ESR1 polymorphisms were associated with cognitive decline as assessed by Chinese versions of Mini-Mental State Examination and Alzheimer Disease Association Scales-Cognitive Subscale. Different sets of ESR1 polymorphisms were associated with cognitive decline from CDR 0 to 0.5 and CDR 0.5 to 1. ESR1 polymorphisms (rs3853248, rs22334693 [ESR1+397], rs9340799 [ESR1+351], rs9397456, rs1801132 [ESR1+975], rs2179922, rs932477, and rs9341016) were associated with the deterioration of episodic memory among subjects with baseline CDR 0, indicating these polymorphisms might be markers for episodic memory decline at an earlier stage.

CONCLUSION

This study showed association between ESR polymorphisms and cognitive decline or specific areas in cognitive profile. These findings might be useful in identifying individuals at risk for early intervention, and more research is required to elucidate the underlying mechanisms.

Oestradiol modulation of cognition in adult female marmosets (Callithrix jacchus)

The common marmoset (Callithrix jacchus) provides many advantages over traditional rodent and macaque species as a model for human ageing and may be very useful for studying the effects of sex steroids on cognitive and brain ageing. We present the first study examining the effects of oestrogens on cognitive function in female marmosets. Adult monkeys (3-5 years of age) were trained to a specific learning criterion on a battery of cognitive tasks preoperatively (object discrimination, delayed response with increasing delays and detour reaching with opaque box) and were tested on different versions of these tasks (object reversals, delayed response with randomised delays and detour reaching with clear box) after ovariectomy and simultaneous implantation with 17β-oestradiol (E2 ) (n = 6) or blank (n = 6) Silastic capsules. Acquisition of a delayed matching-to-position task with a 1-s delay was also administered after completion of these tests. E2 -treated monkeys were significantly impaired on the second reversal and showed an increase in perseverative responding from reversals 1-3. Their performance also tended to be worse than that of control monkeys on the delayed response task. Performance acquisition on the delayed matching-to-position tended to be better in E2 -treated relative to control monkeys, although the group difference did not reach statistical significance. No effect of treatment was detected for detour reaching or affiliative behaviours. Overall, the findings indicate that E2 compromises performance on prefrontally-mediated tasks. The suggestion that E2 may improve acquisition on tasks dependent on the hippocampus will require further validation. These results are discussed in the context of dopaminergic and serotonergic signalling. We conclude that the marmoset is a useful new primate model for examining the effects of oestrogens on cognitive function.

Receptive functions at childbearing age, perimenopause and postmenopause

Introduction:

Receptive functions represents higher mental processes by which people carry out normal daily living tasks. The specificity of these functions is that they stimulate specific physiological functions in the body. They are reflected in the ability to select, classify and integrate the information received.

Material and Methods:

We performed an assessment of visual-perceptual abilities by Purdue nonverbal test (PNT-TV) in 135 patients. Patients are classified into three age groups of 45 patients. The first group consisted of patients of childbearing age (25-39 years), second group of patients in perimenopausal age (40-54 years) and a third group of postmenopausal patients (≥55 years).

Results:

The distribution of the results are statistically different between groups, suggesting that at the onset of menopause there is a decrease of visual-perceptual abilities in patients (Friedman test was significant with p<0.001).

Conclusion:

By the distribution of the results of our study, and the statistical significance of Friedman’s, it can be concluded that patients who enter menopause have tendency to decrease of receptive functions.

Genistein attenuates brain damage induced by transient cerebral ischemia through up-regulation of ERK activity in ovariectomized mice

Stroke has severe consequences in postmenopausal women. As replacement therapy of estrogen have various adverse effects and the undermined outcomes. Genistein, a natural phytoestrogen, has been suggested to be a potential neuroprotective agent for such stroke patients. However, the role of genistein and its underlying mechanism in ovariectomized mice has not yet been evaluated. In the present study, ovariectomized mice were treated with genistein (10 mg/kg) or vehicle daily for two weeks before developing transient cerebral ischemia (middle cerebral artery occlusion). The neurological manifestation was evaluated, and infarct volumes were demonstrated by 2,3,5-triphenyltetrazolium chloride staining at 24 h after reperfusion. In addition, phosphorylation of extracellular signal-regulated kinase (ERK) was detected by Western blotting and immunofluorescence staining, and cellular apoptosis was evaluated in the ischemic penumbra. We found that treatment with genistein reduced infarct volumes, improved neurological outcomes and attenuated cellular apoptosis at 24 h after reperfusion. ERK1/2 showed increased phosphorylation by genistein treatment after reperfusion, and an ERK1/2 inhibitor U0126 abolished this protective effect of genistein in terms of infarct volumes, neurological scores and cellular apoptosis. Our findings indicate that treatment with genistein can reduce the severity of subsequent stroke episodes, and that this beneficial function is associated with ERK activation.

Down-regulation of serum gonadotropins but not estrogen replacement improves cognition in aged-ovariectomized 3xTg AD female mice

Development of Alzheimer's disease (AD) has been linked to the de-regulation of estrogen and gonadotropins such as luteinizing hormone (LH). In this study, we found increases in AD pathology in the hippocampi of aged female 3xTg AD mice after ovariectomy that were unable to be reduced by estrogen therapy or down-regulation of serum LH levels. Despite the lack of effect of these treatments on AD pathology, down-regulation of serum LH but not estrogen improved factors associated with neuronal plasticity such as spatial memory, inhibition of glycogen synthase kinase-3 beta, expression of beta-catenin, and brain-derived neurotrophic factor transcription. Contrasting previous studies in younger mice, estrogen replacement was not able to rescue behavioral deficits, reduced glycogen synthase kinase-3 beta inhibition and increased hippocampal phosphorylation of tau. Of critical importance, serum LH was negatively correlated with brain LH in regions associated with spatial memory, and increases in brain LH correlated with cognitive improvement. This paralleled changes in human female AD brains which showed a significant reduction in brain LH mRNA compared to healthy age- and PMI-matched controls. Taken together, these findings should promote further research into the LH-dependent mechanisms associated with AD cognitive deficits as well as the effects of estrogen within the aged brain. In the aged triple transgenic Alzheimer's disease (AD) mouse model (3xAD-Tg), estrogen replacement after ovariectomy does not improve cognitive function, increases phosphorylated Tau levels and decreases inhibition of GSK3 beta. Luprolide acetate rescues ovariectomy-dependent cognitive function, increases signaling events associated with synaptic plasticity including GSK3 beta inhibition, but does not alter AD pathology. In the human AD female brain, luteinizing hormone (LH) mRNA levels are reduced. In the 3XAD-tg model, brain LH protein levels are reduced by ovariectomy and normalized by leuprolide acetate treatment. These treatment-dependent normalization of LH positively correlates with markers of neuroplasticity and cognitive improvement.

Alzheimer disease in post-menopausal women: Intervene in the critical window period

Alzheimer disease (AD) is a crippling neurodegenerative disorder. It is more common in females after menopause. Estrogen probably has a protective role in cognitive decline. Large amount of research has been carried out to see the benefits of hormone replacement therapy with regards to Alzheimer still its neuroprotective effect is not established. Recent studies suggest a reduced risk of AD and improved cognitive functioning of post-menopausal women who used 17 β-estradiol in the critical period. Use of 17 β-estradiol in young and healthy post-menopausal women yields the maximum benefit when the neurons are intact or neuronal stress has just started. Hence intervention in the critical period is key in the prevention or delay of AD in post-menopausal women.

Statin use and incident dementia: a nationwide cohort study of Taiwan

BACKGROUND

Statins are widely used in clinical treatment. However, an U.S. Food and Drug Administration issued health alert has raised concerns for the adverse effects of statin-associated confusion and memory loss in the elderly people. It is necessary to clarify the relationship between statin use and risk of incident dementia as well as whether class effects exist.

METHODS

In this population-based retrospective cohort study, total 33,398 patients aged ≥ 60 years were selected from a subset of the Taiwan National Health Insurance Research Databases and followed up for tracking the occurrence of any type of dementia from 2000 to 2010. The Cox proportional hazards models were used.

RESULTS

Compared to nonusers, statin users had a significantly lower risk of incident dementia (hazard ratio [HR], 0.78; 95% CI, 0.72-0.85, p<0.001). The potency and the cumulative duration of statin utilized were associated with the reducing risk of dementia. After stratifying by gender, the risk of incident dementia was lower in female statin users (HR, 0.76; 95% CI, 0.68-0.85, p<0.001) than in male statin users (HR, 0.86; 95% CI, 0.75-0.98, p=0.024). Higher potency and longer cumulative duration of statin use were required for reducing the risk of incident dementia in male patients than in female patients.

CONCLUSION

Statin use was associated with a significantly lower risk of dementia in the elderly patients in Taiwan. The potency and the cumulative duration of statin utilized played critical roles.

Guidelines for the prevention of stroke in women: a statement for healthcare professionals from the American Heart Association/American Stroke Association

PURPOSE

The aim of this statement is to summarize data on stroke risk factors that are unique to and more common in women than men and to expand on the data provided in prior stroke guidelines and cardiovascular prevention guidelines for women. This guideline focuses on the risk factors unique to women, such as reproductive factors, and those that are more common in women, including migraine with aura, obesity, metabolic syndrome, and atrial fibrillation.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council's Scientific Statement Oversight Committee and the AHA's Manuscript Oversight Committee. The panel reviewed relevant articles on adults using computerized searches of the medical literature through May 15, 2013. The evidence is organized within the context of the AHA framework and is classified according to the joint AHA/American College of Cardiology and supplementary AHA Stroke Council methods of classifying the level of certainty and the class and level of evidence. The document underwent extensive AHA internal peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

We provide current evidence, research gaps, and recommendations on risk of stroke related to preeclampsia, oral contraceptives, menopause, and hormone replacement, as well as those risk factors more common in women, such as obesity/metabolic syndrome, atrial fibrillation, and migraine with aura.

CONCLUSIONS

To more accurately reflect the risk of stroke in women across the lifespan, as well as the clear gaps in current risk scores, we believe a female-specific stroke risk score is warranted.

Therapeutic options in Alzheimer’s disease

Alzheimer's disease (AD) places an enormous burden on individuals, families and society. Consequently, a tremendous effort is being devoted to the development of drugs that prevent or delay neurodegeneration. Current pharmacological treatments are based on the use of acetylcholinesterase inhibitors or memantine, a N-methyl-D-aspartate channel blocker. However, new therapeutic approaches, including those more closely targeted to the pathogenesis of the disease, are being developed. These potentially disease-modifying therapeutics include secretase inhibitors, cholesterol-lowering drugs, amyloid-beta immunotherapy, nonsteroidal anti-inflammatory drugs, hormonal modulation and the use of antioxidants. The possibility that oxidative stress is a primary event in AD indicates that antioxidant-based therapies are perhaps the most promising weapons against this devastating neurodegenerative disorder.

Estrogen and memory system bias in females across the lifespan

Studies in both rodents and humans have made much progress in shedding light on how fluctuations in ovarian hormones can affect memory in women across the lifespan. Specifically, advances in neuroscience have identified multiple memory systems that are each mediated by different brain areas. Two memory systems used to navigate an environment are ‘place’ and ‘response’ memory. They are defined as either using an allocentric strategy: using a spatial or cognitive map of the surroundings, or an egocentric strategy: using habitual-turns/movements, respectively. Studies in neuroendocrinology have shown that estrogen levels can bias a female to use one memory system over another to solve a task, such that high estrogen levels are associated with using place memory and low levels with using response memory. Furthermore, recent advances in identifying and localizing estrogen receptors in the rodent brain are uncovering which brain regions are affected by estrogen and providing insight into how hormonal fluctuations during the menstrual cycle, pregnancy, and menopause might affect which memory system is facilitated or impaired in women at different life stages. These studies can help point the way to improving cognitive health in women.

Cardiovascular disease and cognitive decline in postmenopausal women: results from the Women's Health Initiative Memory Study

BACKGROUND

Data on cardiovascular diseases (CVD) and cognitive decline are conflicting. Our objective was to investigate if CVD is associated with an increased risk for cognitive decline and to examine whether hypertension, diabetes, or adiposity modify the effect of CVD on cognitive functioning.

METHODS AND RESULTS

Prospective follow-up of 6455 cognitively intact, postmenopausal women aged 65 to 79 years old enrolled in the Women's Health Initiative Memory Study (WHIMS). CVD was determined by self-report. For cognitive decline, we assessed the incidence of mild cognitive impairment (MCI) or probable dementia (PD) via modified mini-mental state examination (3 MS) score, neurocognitive, and neuropsychiatric examinations. The median follow-up was 8.4 years. Women with CVD tended to be at increased risk for cognitive decline compared with those free of CVD (hazard ratio [HR], 1.29; 95% CI: 1.00, 1.67). Women with myocardial infarction or other vascular disease were at highest risk (HR, 2.10; 95% CI: 1.40, 3.15 or HR, 1.97; 95% CI: 1.34, 2.87). Angina pectoris was moderately associated with cognitive decline (HR 1.45; 95% CI: 1.05, 2.01) whereas no significant relationships were found for atrial fibrillation or heart failure. Hypertension and diabetes increased the risk for cognitive decline in women without CVD. Diabetes tended to elevate the risk for MCI/PD in women with CVD. No significant trend was seen for adiposity.

CONCLUSIONS

CVD is associated with cognitive decline in elderly postmenopausal women. Hypertension and diabetes, but not adiposity, are associated with a higher risk for cognitive decline. More research is warranted on the potential of CVD prevention for preserving cognitive functioning.

Age at surgical menopause influences cognitive decline and Alzheimer pathology in older women

OBJECTIVE

To determine the association between age at surgical menopause and both cognitive decline and Alzheimer disease (AD) pathology in 2 longitudinal cohorts.

METHODS

Female subjects from 2 longitudinal studies of cognitive decline (Religious Orders Study and Rush Memory and Aging Project) were included (total n = 1,884). The primary analysis examined the association between age at surgical menopause and decline in a global cognition score. Secondary analyses examined additional outcomes: 1) decline in 5 cognitive subdomains and 2) a global measure of the burden of AD pathology. In exploratory analyses, we examined the effect of hormone replacement therapy (HRT). We adjusted all models for age, education, smoking, and cohort and stratified by surgical vs natural menopause.

RESULTS

For the 32% of subjects with surgical menopause, earlier age at menopause was associated with faster decline in global cognition (p = 0.0007), specifically episodic memory (p = 0.0003) and semantic memory (p = 0.002). Earlier age at menopause was also associated with increased AD neuropathology (p = 0.038), in particular neuritic plaques (p = 0.013). HRT use for at least 10 years, when administered within a 5-year perimenopausal window, was associated with decreased decline in global cognition. No associations were seen in women who had natural menopause.

CONCLUSIONS

Early age at surgical menopause was associated with cognitive decline and AD neuropathology. Ongoing studies should clarify the potential effect of HRT on this relationship.

The Cache County Study on Memory in Aging: factors affecting risk of Alzheimer's disease and its progression after onset

The Cache County Study on Memory in Aging is a longitudinal, population-based study of Alzheimer's disease (AD) and other dementias. Initiated in 1995 and extending to 2013, the study has followed over 5,000 elderly residents of Cache County, Utah (USA) for over twelve years. Achieving a 90% participation rate at enrolment, and spawning two ancillary projects, the study has contributed to the literature on genetic, psychosocial and environmental risk factors for AD, late-life cognitive decline, and the clinical progression of dementia after its onset. This paper describes the major study contributions to the literature on AD and dementia.

Sex, hormones and neurogenesis in the hippocampus: hormonal modulation of neurogenesis and potential functional implications

The hippocampus is an area of the brain that undergoes dramatic plasticity in response to experience and hormone exposure. The hippocampus retains the ability to produce new neurones in most mammalian species and is a structure that is targeted in a number of neurodegenerative and neuropsychiatric diseases, many of which are influenced by both sex and sex hormone exposure. Intriguingly, gonadal and adrenal hormones affect the structure and function of the hippocampus differently in males and females. Adult neurogenesis in the hippocampus is regulated by both gonadal and adrenal hormones in a sex- and experience-dependent way. Sex differences in the effects of steroid hormones to modulate hippocampal plasticity should not be completely unexpected because the physiology of males and females is different, with the most notable difference being that females gestate and nurse the offspring. Furthermore, reproductive experience (i.e. pregnancy and mothering) results in permanent changes to the maternal brain, including the hippocampus. This review outlines the ability of gonadal and stress hormones to modulate multiple aspects of neurogenesis (cell proliferation and cell survival) in both male and female rodents. The function of adult neurogenesis in the hippocampus is linked to spatial memory and depression, and the present review provides early evidence of the functional links between the hormonal modulation of neurogenesis that may contribute to the regulation of cognition and stress.

The innate and adaptive immunological aspects in neurodegenerative diseases

Neurodegenerative diseases affect a considerable percentage of the elderly population. New therapeutic approaches are warranted, aiming to at least delay and possibly reverse disease progression. Strategies to elaborate such approaches require knowledge of specific immune system involvement in disease pathogenesis. In this review, innate and adaptive immunological aspects of neurodegenerative disorders, in particular Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS), are discussed. Initiating disease factors, as well as common mechanistic pathways, are detailed and potential immunological therapeutic targets are identified.

Postmenopausal hormone therapy is not associated with risk of all-cause dementia and Alzheimer's disease

The relationship of postmenopausal hormone therapy with all-cause dementia and Alzheimer's disease dementia has been controversial. Given continued interest in the role of hormone therapy in chronic disease prevention and the emergence of more prospective studies, we conducted a systematic review to identify all epidemiologic studies meeting prespecified criteria reporting on postmenopausal hormone therapy use and risk of Alzheimer's disease or dementia. A systematic search of Medline and Embase through December 31, 2012, returned 15 articles meeting our criteria. Our meta-analysis of any versus never use did not support the hypothesis that hormone therapy reduces risk of Alzheimer's disease (summary estimate = 0.88, 95% confidence interval: 0.66, 1.16). Exclusion of trial findings did not change this estimate. There were not enough all-cause dementia results for a separate meta-analysis, but when we combined all-cause dementia results (n = 3) with Alzheimer's disease results (n = 7), the summary estimate remained null (summary estimate = 0.94, 95% confidence interval: 0.71, 1.26). The limited explorations of timing of use-both duration and early initiation-did not yield consistent findings. Our findings support current recommendations that hormone therapy should not be used for dementia prevention. We discuss trends in hormone therapy research that could explain our novel findings and highlight areas where additional data are needed.

Long-term effects on cognitive function of postmenopausal hormone therapy prescribed to women aged 50 to 55 years

IMPORTANCE

Postmenopausal hormone therapy with conjugated equine estrogens (CEEs) may adversely affect older women’s cognitive function. It is not known whether this extends to younger women.

OBJECTIVE

To test whether prescribing CEE-based hormone therapy to postmenopausal women aged 50 to 55 years has longer-term effects on cognitive function.

DESIGN

Trained, masked staff assessed participants with an annual telephone-administered cognitive battery that included measures of global and domain-specific cognitive functions. Cognitive testing was conducted an average of 7.2 years after the trials ended, when women had a mean age of 67.2 years, and repeated 1 year later. Enrollment occurred from 1996 through 1999.

SETTING

Forty academic research centers.

PARTICIPANTS

The study population comprised 1326 postmenopausal women, who had begun treatment in 2 randomized placebo-controlled clinical trials of hormone therapy when aged 50 to 55 years.

INTERVENTION

The clinical trials in which the women had participated had compared 0.625 mg CEE with or without 2.5 mg medroxyprogesterone acetate over a mean of 7.0 years.

MAIN OUTCOMES AND MEASURES

The primary outcome was global cognitive function. Secondary outcomes were verbal memory, attention, executive function, verbal fluency, and working memory.

RESULTS

Global cognitive function scores from women who had been assigned to CEE-based therapies were similar to those from women assigned to placebo: mean (95% CI) intervention effect of 0.02 (−0.08 to 0.12) standard deviation units (P = .66). Similarly, no overall differences were found for any individual cognitive domain (all P > .15). Prespecified subgroup analyses found some evidence that CEE-based therapies may have adversely affected verbal fluency among women who had prior hysterectomy or prior use of hormone therapy: mean treatment effects of −0.17 (−0.33 to −0.02) and −0.25 (−0.42 to −0.08), respectively; however, this may be a chance finding.

CONCLUSIONS AND RELEVANCE

CEE-based therapies produced no overall sustained benefit or risk to cognitive function when administered to postmenopausal women aged 50 to 55 years. We are not able to address whether initiating hormone therapy during menopause and maintaining therapy until any symptoms are passed affects cognitive function, either in the short or longer term.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01124773.

Psychological advocacy toward healing (PATH): study protocol for a randomized controlled trial

Background

Domestic violence and abuse (DVA), defined as threatening behavior or abuse by adults who are intimate partners or family members, is a key public health and clinical priority. The prevalence of DVA in the United Kingdom and worldwide is high, and its impact on physical and mental health is detrimental and persistent. There is currently little support within healthcare settings for women experiencing DVA. Psychological problems in particular may be difficult to manage outside specialist services, as conventional forms of therapy such as counseling that do not address the violence may be ineffective or even harmful. The aim of this study is to assess the overall effectiveness and cost-effectiveness of a novel psychological intervention tailored specifically for survivors of DVA and delivered by domestic violence advocates based in third-sector organizations.

Methods and study design

This study is an open, pragmatic, parallel group, individually randomized controlled trial. Women ages 16 years and older experiencing domestic violence are being enrolled and randomly allocated to receive usual DVA agency advocacy support (control) or usual DVA agency support plus psychological intervention (intervention). Those in the intervention group will receive eight specialist psychological advocacy (SPA) sessions weekly or fortnightly, with two follow-up sessions, 1 month and then 3 months later. This will be in addition to any advocacy support sessions each woman receives. Women in the control group will receive usual DVA agency support but no additional SPA sessions. The aim is to recruit 250 women to reach the target sample size. The primary outcomes are psychological well-being and depression severity at 1 yr from baseline, as measured by the Clinical Outcomes in Routine Evaluation–Outcome Measure (CORE-OM) and the Patient Health Questionnaire (PHQ-9), respectively. Secondary outcome measures include anxiety, posttraumatic stress, severity and frequency of abuse, quality of life and cost-effectiveness of the intervention. Data from a subsample of women in both groups will contribute to a nested qualitative study with repeat interviews during the year of follow-up.

Discussion

This study will contribute to the evidence base for management of the psychological needs of women experiencing DVA. The findings will have important implications for healthcare commissioners and providers, as well as third sector specialist DVA agencies providing services to this client group.

Trial registration

ISRCTN58561170

Progesterone, compared to medroxyprogesterone acetate, to C57BL/6, but not 5α-reductase mutant, mice enhances object recognition and placement memory and is associated with higher BDNF levels in the hippocampus and cortex

Progesterone (P4) may influence cognition in part through actions of its 5α-reduced metabolite, allopregnanolone. Ovariectomized mice that were C57BL/6 wildtype (WT), or deficient in the 5α-reductase Type 1 enzyme (5α-reductase knockout; 5αRKO), were administered vehicle, P4, allopregnanolone, or medroxyprogesterone acetate (MPA) after training in the object recognition or placement tasks. WT mice administered P4 or allopregnanolone performed significantly better in the object recognition and placement tasks than did WT mice administered vehicle or MPA. 5αRKO mice administered allopregnanolone, but not P4, MPA, or vehicle showed enhanced performance in the object recognition and placement tasks. Levels of brain-derived neurotrophic factor (BDNF) in the prefrontal cortex and hippocampus were lowest among mice administered MPA. Thus, some of P4s effects to enhance cognitive performance may be incumbent upon its 5α-reduction.

Estrogen signaling and the aging brain: context-dependent considerations for postmenopausal hormone therapy

Recent clinical studies have spurred rigorous debate about the benefits of hormone therapy (HT) for postmenopausal women. Controversy first emerged based on a sharp increase in the risk of cardiovascular disease in participants of the Women's Health Initiative (WHI) studies, suggesting that decades of empirical research in animal models was not necessarily applicable to humans. However, a reexamination of the data from the WHI studies suggests that the timing of HT might be a critical factor and that advanced age and/or length of estrogen deprivation might alter the body's ability to respond to estrogens. Dichotomous estrogenic effects are mediated primarily by the actions of two high-affinity estrogen receptors alpha and beta (ER α & ER β ). The expression of the ERs can be overlapping or distinct, dependent upon brain region, sex, age, and exposure to hormone, and, during the time of menopause, there may be changes in receptor expression profiles, post-translational modifications, and protein:protein interactions that could lead to a completely different environment for E2 to exert its effects. In this review, factors affecting estrogen-signaling processes will be discussed with particular attention paid to the expression and transcriptional actions of ER β in brain regions that regulate cognition and affect.

Progesterone antagonism of neurite outgrowth depends on microglial activation via Pgrmc1/S2R

Neuronal plasticity is regulated by the ovarian steroids estradiol (E2) and progesterone (P4) in many normal brain functions, as well as in acute response to injury and chronic neurodegenerative disease. In a female rat model of axotomy, the E2-dependent compensatory neuronal sprouting is antagonized by P4. To resolve complex glial-neuronal cell interactions, we used the "wounding-in-a-dish" model of neurons cocultured with astrocytes or mixed glia (microglia to astrocytes, 1:3). Although both astrocytes and mixed glia supported E2-enhanced neurite outgrowth, P4 antagonized E2-induced neurite outgrowth only with mixed glia, but not astrocytes alone. We now show that P4-E2 antagonism of neurite outgrowth is mediated by microglial expression of progesterone receptor (Pgr) membrane component 1 (Pgrmc1)/S2R, a putative nonclassical Pgr mediator with multiple functions. The P4-E2 antagonism of neurite outgrowth was restored by add-back of microglia to astrocyte-neuron cocultures. Because microglia do not express the classical Pgr, we examined the role of Pgrmc1, which is expressed in microglia in vitro and in vivo. Knockdown by siRNA-Pgrmc1 in microglia before add-back to astrocyte-neuron cocultures suppressed the P4-E2 antagonism of neurite outgrowth. Conditioned media from microglia restored the P4-E2 activity, but only if microglia were activated by lipopolysaccharide or by wounding. Moreover, the microglial activation was blocked by Pgmrc1-siRNA knockdown. These findings explain why nonwounded cultures without microglial activation lack P4 antagonism of E2-induced neurite outgrowth. We suggest that microglial activation may influence brain responses to exogenous P4, which is a prospective therapy in traumatic brain injury.

Multiple clinically relevant hormone therapy regimens fail to improve cognitive function in aged ovariectomized rhesus monkeys

Preclinical studies in aged, surgically-menopausal rhesus monkeys have revealed powerful benefits of intermittent estrogen injections on prefrontal cortex-dependent working memory, together with corresponding effects on dendritic spine morphology in the prefrontal cortex. This contrasts with the inconsistent effects of hormone therapy (HT) reported in clinical studies in women. Factors contributing to this discrepancy could include differences in the formulation and sequence of HT regimens, resulting in different neurobiological outcomes. The current study evaluated, in aging surgically menopausal rhesus monkeys, the cognitive effects of 4 HT regimens modeled directly on human clinical practice, including continuous estrogen treatment opposed by progesterone. None of the regimens tested produced any cognitive effect, despite yielding physiologically relevant serum hormone levels, as intended. These findings have implications for the design of regimens that might optimize the benefits of hormone treatment for healthy aging, and suggest that common HT protocols used by women may fail to result in substantial cognitive benefit, at least via direct effects on the prefrontal cortex.

Effect of black cohosh (cimicifuga racemosa) on vasomotor symptoms in postmenopausal women: a randomized clinical trial

INTRODUCTION

Hot flash is considered to be an early and common symptom of menopause. The present study aimed to determine the impact of black cohosh (Cimicifuga racemosa) on vasomotor symptoms in postmenopausal women.

METHODS

This was a randomized, double-blind, placebo-controlled clinical trial. This study was performed on 84 postmenopausal women. The participants were randomly divided into control and intervention groups. The participants of the intervention group received one black cohosh tablet per day and the control group received one placebo tablet per day for eight weeks. The severity of vasomotor symptoms and number of hot flashes were recorded during the pre-intervention phase, and 4 and 8 weeks after the intervention. The data were analyzed using repeated measures ANOVA and ANCOVA tests. The level of significance was considered lower than 0.05.

RESULTS

There was a significant difference between the two groups in terms of severity and number of hot flashes in weeks 4 and 8 by controlling the intensity of vasomotor symptoms and number of hot flashes before the intervention. Moreover, using repeated measures ANOVA, the intergroup comparison indicated a significant difference in bothgroups (the test and control groups) in terms of severity of vasomotor symptoms and number of hot flashes.

CONCLUSION

According to the findings of the study, it seems that black cohosh can be used as an effective alternative medicine in relieving menopausal vasomotor symptoms.

Rationale and design of the Kronos Early Estrogen Prevention Study (KEEPS) and the KEEPS Cognitive and Affective sub study (KEEPS Cog)

This manuscript describes the study design and rationalle for the Kronos Early Estrogen Prevention Study (KEEPS) and the KEEPS Cognitive and Affective ancillary study (KEEPS Cog). KEEPS is a multicenter, randomized, double-blinded, placebo-controlled trial, designed to test the hypothesis that low-dose hormone therapy (HT) initiated in recently postmenopausal women will reduce the progression of subclinical atherosclerosis as measured by carotid artery intima-media thickness (CIMT) and coronary artery calcification (CAC) over four years. The KEEPS Cog ancillary study was designed to assess potential estrogenic treatment effects on cognition and mood. We present the KEEPS trial in the context of issues raised by the Women's Health Initiative (WHI) and the Women's Health Initiative Memory Study (WHIMS). Here we also describe the most recent results and ongoing HT-related research studies designed to address similar issues. This article is part of a Special Issue entitled Hormone Therapy.

The rationale, design, and baseline characteristics of the Women's Health Initiative Memory Study of Younger Women (WHIMS-Y)

The Women's Health Initiative Memory Study-Younger (WHIMS-Y) was designed to assess the effect of prior random assignment to hormone therapy (HT) (conjugated equine estrogen (CEE) alone or CEE plus medroxyprogesterone acetate (MPA)) on global cognitive function in younger middle-aged women relative to placebo. WHIMS-Y was an ancillary study to the Women's Health Initiative (WHI) HT trial and enrolled 1361 women who were aged 50-55 years and postmenopausal at WHI enrollment. WHIMS-Y will examine whether an average of 5.4 years of HT during early menopause has longer term protective effects on global cognitive function and if these effects vary by regimen, time between menopause and study initiation, and prior use of HT. We present the study rationale and design. We describe enrollment, adherence to assigned WHI therapy, and compare risk factor characteristics of the WHIMS-Y cohort at the time of WHI enrollment to similar aged women in the WHI HT who did not enroll in WHIMS-Y. Challenges of WHIMS-Y include lower than expected and differential enrollment. Strengths of WHIMS-Y include balance in baseline risk factors between treatment groups, standardized and masked data collection, and high rates of retention and on-trial adherence and exposure. In addition, the telephone-administered cognitive battery showed adequate construct validity. WHIMS-Y provided an unprecedented chance to examine the hypothesis that HT may have protective effects on cognition in younger postmenopausal women aged 50-55 years. Integrated into the WHI, WHIMS-Y optimized the experience of WHI investigators to ensure high retention and excellent quality assurance across sites. This article is part of a Special Issue entitled Hormone Therapy.

Sex-specific risk of cardiovascular disease and cognitive decline: pregnancy and menopause

Understanding the biology of sex differences is integral to personalized medicine. Cardiovascular disease and cognitive decline are two related conditions, with distinct sex differences in morbidity and clinical manifestations, response to treatments, and mortality. Although mortality from all-cause cardiovascular diseases has declined in women over the past five years, due in part to increased educational campaigns regarding the recognition of symptoms and application of treatment guidelines, the mortality in women still exceeds that of men. The physiological basis for these differences requires further research, with particular attention to two physiological conditions which are unique to women and associated with hormonal changes: pregnancy and menopause. Both conditions have the potential to impact life-long cardiovascular risk, including cerebrovascular function and cognition in women. This review draws on epidemiological, translational, clinical, and basic science studies to assess the impact of hypertensive pregnancy disorders on cardiovascular disease and cognitive function later in life, and examines the effects of post-menopausal hormone treatments on cardiovascular risk and cognition in midlife women. We suggest that hypertensive pregnancy disorders and menopause activate vascular components, i.e., vascular endothelium and blood elements, including platelets and leukocytes, to release cell-membrane derived microvesicles that are potential mediators of changes in cerebral blood flow, and may ultimately affect cognition in women as they age. Research into specific sex differences for these disease processes with attention to an individual's sex chromosomal complement and hormonal status is important and timely.

Geriatric syndromes and incident disability in older women: results from the women's health initiative observational study

OBJECTIVES

To determine how the number of geriatric syndromes is associated with incident disability in community-based populations of older adults.

DESIGN

Longitudinal analysis from the Women's Health Initiative Observational Study (WHI-OS).

SETTING

Community.

PARTICIPANTS

Twenty-nine thousand five hundred forty-four women aged 65 and older enrolled in the WHI-OS and free of disability in activities of daily living (ADLs) at baseline.

MEASUREMENTS

Geriatric syndromes (high depressive symptoms, dizziness, falls, hearing or visual impairment, osteoporosis, polypharmacy, syncope, sleep disturbance, and urinary incontinence) were self-reported at baseline and 3-year follow-up. Disability was defined as dependence in any ADL and was assessed at baseline and follow-up. Chronic diseases were measured according to a modified Charlson Index.

RESULTS

Geriatric syndromes were common in this population of women; 76.3% had at least one syndrome at baseline. Greater number of geriatric syndromes at baseline was significantly associated with greater risk of incident ADL disability at follow-up (P ≤ .001). Adjusted risk ratios were 1.21 (95% confidence interval (CI) = 0.78-1.87) for a single syndrome and 6.64 (95% CI = 4.15-10.62) for five or more syndromes compared with no syndromes. These results were only slightly attenuated after adjustment for number of chronic diseases or pain.

CONCLUSION

Geriatric syndromes are significantly associated with onset of disability in older women; this association is not simply a result of chronic disease or pain. A better understanding of how these conditions contribute to disablement is needed. Geriatric syndrome assessment should be considered along with chronic disease management in the prevention of disability in older women.

Factors influencing the cognitive and neural effects of hormone treatment during aging in a rodent model

Whether hormone treatment alters brain structure or has beneficial effects on cognition during aging has recently become a topic of debate. Although previous research has indicated that hormone treatment benefits memory in menopausal women, several newer studies have shown no effect or detrimental effects. These inconsistencies emphasize the need to evaluate the role of hormones in protecting against age-related cognitive decline in an animal model. Importantly, many studies investigating the effects of estrogen and progesterone on cognition and related brain regions have used young adult animals, which respond differently than aged animals. However, when only the studies that have examined the effects of hormone treatment in an aging model are reviewed, there are still varied behavioral and neural outcomes. This article reviews some of the important factors that can influence the behavioral and neural outcomes of hormone treatment including the type of estrogen administered, whether or not estrogen is combined with progesterone and if so, the type of progesterone used, as well as the route, mode, and length of treatment. How these factors influence cognitive outcomes highlights the importance of study design and avoiding generalizations from a small number of studies. This article is part of a Special Issue entitled Hormone Therapy.

Gender, sex steroid hormones, and Alzheimer's disease

Age-related loss of sex steroid hormones is a established risk factor for the development of Alzheimer's disease (AD) in women and men. While the relationships between the sex steroid hormones and AD are not fully understood, findings from both human and experimental paradigms indicate that depletion of estrogens in women and androgens in men increases vulnerability of the aging brain to AD pathogenesis. We review evidence of a wide range of beneficial neural actions of sex steroid hormones that may contribute to their hypothesized protective roles against AD. Both estrogens and androgens exert general neuroprotective actions relevant to a several neurodegenerative conditions, some in a sex-specific manner, including protection from neuron death and promotion of select aspects of neural plasticity. In addition, estrogens and androgens regulate key processes implicated in AD pathogenesis, in particular the accumulation of β-amyloid protein. We discuss evidence of hormone-specific mechanisms related to the regulation of the production and clearance of β-amyloid as critical protective pathways. Continued elucidation of these pathways promises to yield effective hormone-based strategies to delay development of AD.

Using genetics to enable studies on the prevention of Alzheimer's disease

Curing Alzheimer's disease (AD) remains an elusive goal; indeed, it may even prove to be impossible, given the nature of the disease. Although modulating disease progression is an attractive target and will alleviate the burden of the most severe stages, this strategy will not reduce the prevalence of the disease itself. Preventing or (as described in this article) delaying the onset of cognitive impairment and AD will provide the greatest benefit to individuals and society by pushing the onset of disease into the later years of life. Because of the high variability in the age of onset of the disease, AD prevention studies that do not stratify participants by age-dependent disease risk will be operationally challenging, being large in size and of long duration. We present a composite genetic biomarker to stratify disease risk so as to facilitate clinical studies in high-risk populations. In addition, we discuss the rationale for the use of pioglitazone to delay the onset of AD in individuals at high risk.

Cognitive performance in healthy women during induced hypogonadism and ovarian steroid addback

Gynecology clinic-based studies have consistently demonstrated that induced hypogonadism is accompanied by a decline in cognitive test performance. However, a recent study in healthy asymptomatic controls observed that neither induced hypogonadism nor estradiol replacement influenced cognitive performance. Thus, the effects of induced hypogonadism on cognition might not be uniformly experienced across individual women. Moreover, discrepancies in the effects of hypogonadism on cognition also could suggest the existence of specific risk phenotypes that predict a woman's symptomatic experience during menopause. In this study, we examined the effects of induced hypogonadism and ovarian steroid replacement on cognitive performance in healthy premenopausal women. Ovarian suppression was induced with a GnRH agonist (Lupron) and then physiologic levels of estradiol and progesterone were reintroduced in 23 women. Cognitive tests were administered during each hormone condition. To evaluate possible practice effects arising during repeated testing, an identical battery of tests was administered at the same time intervals in 11 untreated women. With the exception of an improved performance on mental rotation during estradiol, we observed no significant effects of estradiol or progesterone on measures of attention, concentration, or memory compared with hypogonadism. In contrast to studies in which a decline in cognitive performance was observed in women receiving ovarian suppression therapy for an underlying gynecologic condition, we confirm a prior report demonstrating that short-term changes in gonadal steroids have a limited effect on cognition in young, healthy women. Differences in the clinical characteristics of the women receiving GnRH agonists could predict a risk for ovarian steroid-related changes in cognitive performance during induced, and possibly, natural menopause.

Estrogens, estrogen receptors, and female cognitive aging: the impact of timing

Estrogens have been shown to be protective agents against neurodegeneration and associated cognitive decline in aging females. However, clinical data have been equivocal as to the benefits to the brain and cognition of estrogen therapy in postmenopausal women. One factor that is proposed to be critical in determining the efficacy of hormone therapy is the timing of its initiation. The critical period or window of opportunity hypothesis proposes that following long-term ovarian hormone deprivation, the brain and cognition become insensitive to exogenously administered estrogens. In contrast, if estrogens are administered during a critical period near the time of cessation of ovarian function, they will exert beneficial effects. The focus of the current review is the examination of evidence from rodent models investigating the critical period hypothesis. A growing body of experimental data indicates that beneficial effects of 17β-estradiol (estradiol) on cognition and on cholinergic function and hippocampal plasticity, both of which have been linked to the ability of estradiol to exert beneficial effects on cognition, are attenuated if estradiol is administered following a period of long-term ovarian hormone deprivation. Further, emerging data implicate loss of estrogen receptor alpha (ERα) in the brain resulting from long-term hormone deprivation as a basis for the existence of the critical period. A unifying model is proposed by which the presence or absence of estrogens during a critical period following the cessation of ovarian function permanently alters the system resulting in decreased or increased risk, respectively, of neurodegeneration and cognitive decline.

Are there cognitive and neurobehavioural correlates of hormonal neuroprotection for women after TBI?

This study examined possible cognitive correlates of hormonal neuroprotection following traumatic brain injury (TBI) using archival neuropsychological findings for 1563 individuals undergoing acute TBI rehabilitation between 1989 and 2002. Presumed age of menopause was based on the STRAW (Stages of Reproductive Aging) staging system (Soules, 2005; Soules et al., 2001) and general linear model (GLM) analysis of performance on neuropsychological testing by participants across gender and age groups (25-34, 35-44, 45-54, and 55-64) was performed. Hypotheses were (1) women with TBI in the oldest age group would have lower scores on neuropsychological tests and functional outcome measures than women in the younger groups, and (2) men in the oldest age group would have higher scores than women of the same age group. Analyses revealed that oldest females had significantly worse Trails B and SDMT written and oral scores than the youngest females. In addition, oldest females had significantly better Trails B, Rey AVLT and SDMT written scores than the oldest males. Possible cohort exposure to hormone replacement therapy, unknown hormonal status at time of testing, and sample-specific injury characteristics may have contributed to these findings.

17β-Estradiol, but not estrone, increases the survival and activation of new neurons in the hippocampus in response to spatial memory in adult female rats

Estrogens fluctuate across the lifespan in women, with circulating 17β-estradiol levels higher pre-menopause than estrone and circulating estrone levels higher postmenopause than 17β-estradiol. Estrone is a common component of hormone replacement therapies, but research shows that 17β-estradiol may have a greater positive impact on cognition. Previous studies show that acute estrone and 17β-estradiol impact hippocampus-dependent learning and cell proliferation in the dentate gyrus in a dose-dependent manner in adult female rats. The current study explores how chronic treatment with estrone and 17β-estradiol differentially influences spatial learning, hippocampal neurogenesis and activation of new neurons in response to spatial memory. Adult female rats received daily injections of vehicle (sesame oil), or a 10 μg dose of either 17β-estradiol or estrone for 20 days. One day following the first hormone injection all rats were injected with the DNA synthesis marker, bromodeoxyuridine. On days 11-15 after BrdU injection rats were trained on a spatial reference version of the Morris water maze, and five days later (day 20 of estrogens treatment) were given a probe trial to assess memory retention. Cell proliferation was assessed by the endogenous cell cycle marker, Ki67, cell survival was assessed by counting the number and density of BrdU-ir cells in the dentate gyrus and cell activation was assessed by the percentage of BrdU-ir cells that were co-labelled with the immediate early gene product zif268. There were no significant differences between groups in acquisition or retention of Morris water maze. However, the 17β-estradiol group had significantly higher, while the estrone group had significantly lower, levels of cell survival (BrdU-ir cells) in the dentate gyrus compared to controls. Furthermore, rats injected with 17β-estradiol showed significantly higher levels of activation of new neurons in response to spatial memory compared to controls. These results provide insight into how estrogens differentially influence the brain and behavior, and may provide insight into the development of hormone replacement therapies for women.

Language performance in postmenopausal women with and without hormone therapy and men

AIMS

In the current study, we explored the potential effects of hormone therapy (HT) on language functioning in healthy, postmenopausal women and compared them with men of similar ages.

MATERIALS & METHODS

Language functioning on tasks of verbal fluency and object naming was examined in 100 participants (mean age: 61.9 years; 33 HT users, 15 HT non-users and 52 men) at baseline and follow-up (mean follow-up time period: 2.6 years).

RESULTS

At baseline, men had higher composite language scores than HT users. However, HT users demonstrated more improvement over time compared with men, whereas HT non-users performed similarly to men, with no improvement over time. Longer duration of HT use was not associated with improved performance on language tests.

CONCLUSION

These results suggest an association between HT use and better language ability in postmenopausal women.

Hormone-replacement therapy, dementia and stroke

Hormone-replacement therapy (HRT) has been used for more than 40 years to reduce perimenopausal symptoms. Estrogens may protect brain structures and functional systems affected by Alzheimer's disease, which suggests that maintaining high levels of hormones with HRT can protect against Alzheimer's disease. Moreover, high premenopausal estrogen concentrations are thought to be protective against stroke and, consequently, in the past, HRT was considered to be a potential protective agent against stroke. However, large clinical trials have failed to demonstrate a benefit from HRT on either cognitive performance or risk of dementia. In addition, although HRT has been associated with a reduction in the risk of heart disease in observational studies, results regarding stroke have been less clear. Recently, evidence has shown that HRT does not reduce but actually increases vascular risk. Here, the data from the most important studies are examined, concluding that HRT has no beneficial effect on dementia or stroke risk reduction in postmenopausal women.

Meta-analyses of the effect of hormone treatment on cognitive function in postmenopausal women

As we age, most of us experience a certain degree of cognitive decline. In most cases, this decline is gradual. However, in some cases, cognitive impairment is so severe that it can be classified as dementia and this impacts greatly on activities of daily living. Alzheimer's disease, the most common form of dementia, has been linked to the reduction in estrogen levels that comes with aging. More specifically, many researchers have hypothesized that estrogen, and hence estrogen replacement via hormone therapy, could protect against cognitive decline in women. However, recent randomized, controlled trials did not reflect this. In fact, some reports showed that hormone therapy could have detrimental effects on cognitive function in older postmenopausal women. The most publicized of these has been the Women's Health Initiative Memory Study. Studies have thus yielded conflicting results and conclusions. The reasons for this may be due to a number of factors, such as the age of participants, the time of hormone therapy onset ('window of opportunity' theory), type of treatment, type of menopause (surgical or natural) and, possibly, genetic risk factors. We performed quantitative and qualitative meta-analyses and reviewed each of these factors in detail. The future may lie in combining these factors in order to fully understand the potential mechanisms behind estrogen and its effect on cognition.

Relationship between the neuroprotective effects of insulin-like growth factor-1 and 17β-oestradiol in human neuroblasts

Insulin-like growth factor-1 (IGF-1) and oestrogens interact with each other as neuroprotective factors. We have previously demonstrated that 17β-oestradiol protects against β-amyloid and oxidative stress toxicity and increases the amount of cell cholesterol in human foetal neuroblasts (FNC). The present study aimed: (i) to assess the protective effects of IGF-1 in FNC cells; (ii) to investigate the relationship between IGF-1 and 17β-oestradiol; and (iii) to determine whether cholesterol was a major mediator of the effects of IGF-1, similarly to 17β-oestradiol. We found that IGF-1 effectively exerts neuroprotective effects in FNC cells. We also demonstrated that the IGF-1 receptor (IGF-1R) pathway is needed to maintain oestrogen-mediated neuroprotection. Finally, we found that, opposite to 17β-oestradiol, IGF-1 did not cause a significant increase in cell cholesterol. These findings indicate that a cross-talk between IGF-1 and 17β-oestradiol occurs in FNC cells. In particular, the activation of the IGF-1R cascade appears to be fundamental to warrant 17β-oestradiol-mediated neuroprotection, even though cell cholesterol does not play a major role as an effector of this pathway.

Using predictors of hormone therapy use to model the healthy user bias: how does healthy user status influence cognitive effects of hormone therapy?

OBJECTIVE

This study investigated the phenomenon known as the healthy user bias by equating hormone therapy (HT) use (past or current) with healthy user status.

METHODS

Data from the Survey of Midlife in the United States were used to identify the predictors of HT use. The unique Survey of Midlife in the United States data include psychological, demographic, health-related, and behavioral variables as well as history of HT use. Predictors of HT use were combined to derive propensity scores, describing the likelihood that a woman was an HT user, based on her psychological, demographic, physical, and behavioral profile (ie, likelihood of being a healthy user) as opposed to her actual use of HT. Finally, cognitive performance on an executive function test was examined in women stratified by propensity score.

RESULTS

Using a multiple logistic regression model, nine variables emerged as predictors of HT use. The nine variables were used to estimate the propensity or conditional probability of using HT for each subject; resultant propensity scores were ranked and divided into tertiles. Women in the highest tertile demonstrated shorter median response latencies on a test of executive function than did women who did not use HT.

CONCLUSIONS

From an array of psychological, medical, and behavioral variables, nine emerged as predictors of HT use. If validated, these features may serve as a means of estimating the phenomenon known as healthy user bias. Moreover, these data suggest that the degree to which a woman fits a model of a healthy user may influence cognitive response to HT.

Neuroprotection and estrogen receptors

This review is intended to assess the state of current knowledge on the role of estrogen receptors (ERs) in the neuroprotective effects of estrogens in models for acute neuronal injury and death. We evaluate the overall evidence that estrogens are neuroprotective in acute injury and critically assess the role of ERα, ERβ, GPR 30, and nonreceptor-mediated mechanisms in these robust neuroprotective effects of this ovarian steroid hormone. We conclude that all three receptors, as well as nonreceptor-mediated mechanisms can be involved in neuroprotection, depending on the model used, the level of estrogen administrated, and the mode of administration of the steroid. Also, the signaling pathways used by both ER-dependent and ER-independent mechanisms to exert neuroprotection are considered. Finally, further studies that are needed to parse out the relative contribution of receptor versus nonreceptor-mediated signaling are discussed.

Placental extract improves hippocampal neuronal loss and fear memory impairment resulting from chronic restraint stress in ovariectomized mice

We have recently found that combination of ovariectomy (OVX) and chronic restraint stress causes cognitive dysfunction and reduces hippocampal CA3 neurons in female rats and mice and that estrogen replacement and chronic treatment with Ginkgo biloba extract EGb 761 suppress the OVX/stress-induced behavioral and morphological changes. In this study, we examined the effect of placental extract on the memory impairment and neuromorphological change in OVX/stress-subjected mice. Female Slc:ICR strain mice were randomly divided into four groups: vehicle-treated OVX, porcine placental extract (120 and 2160 mg/kg)-treated OVX, and sham-operated control groups. Two weeks after surgical operation, OVX mice underwent restraint stress for 21 days (6 h/day), and all animals were then subjected to a contextual fear conditioning test followed by morphological examination by Nissl staining. Placental extract was orally administered once daily until the behavioral analysis was carried out. Chronic treatment with both doses of placental extract improved the OVX/stress-induced fear memory impairment and Nissl-positive cell loss of the hippocampal CA3 region, although it did not affect the loss of bone mineral density and increase in body weight after OVX. These results have important implications for the neuroprotective and cognition-enhancing effects of placental extract in postmenopausal women.

The Implications of Body Fat Mass and Fat Distribution for Cognitive Function in Elderly Women

OBJECTIVE

To investigate how body fat mass, an established source of endogenous estrogen after menopause, influences cognitive impairment in elderly women.

RESEARCH METHODS AND PROCEDURES

Study participants were 5607 generally healthy postmenopausal women with mean age of 63.8 years at baseline followed for an average of 7.3 years. Cognitive function assessed at follow-up using the short Blessed test was related to baseline body weight, the yearly change in weight, and follow-up measures of body fat depots assessed by DXA. Cognitive function was also related to various surrogates of lifetime estrogen exposure.

RESULTS

Women with the worst cognitive performance (score >or= 9) at follow-up were the ones who lost the most body weight and revealed the lowest central fat mass (CFM). The association of weight loss with worse cognitive performance was apparent across all age groups except for those more than 80 years old. In the multivariate logistic model, the risk of cognitive impairment was 18% lower in women in the second quartile of CFM (p = 0.14), 32% lower in the third (p = 0.01), and 48% lower in the fourth (p < 0.001) compared with those in the first quartile. CFM showed significant correlation with the simultaneously measured serum estradiol (r = 0.25; p < 0.001). Cognitive score showed an inverse linear relationship with the duration of reproductive period and bone mineral density assessed at follow-up.

DISCUSSION

These findings argue for a protective association of body fat mass with cognitive impairment in elderly women. This association seems to involve a more prominent exposure to endogenous estrogens.