Menopause and cognitive function: estrogens and alternative therapies

Effects of soy isoflavones on the uterus and urethra of ovariectomized rats

OBJECTIVE

To evaluate the effect of soy isoflavone extract (SIE) on the uterus and urethra of castrated female rats.

METHODS

Ovariectomized adult virgin Wistar rats (n = 45) received, for 30 days: placebo (GI); SIE from day 5 of castration (GII); or day 28 of castration (GIII). A standardized SIE was administered by gavage at 125 microg genistein/g body weight/day, with a soy-free diet. Average numbers of nuclei (NU), blood vessels (BV) and collagen fibers (CF) in uterus and mid-urethra sections were compared using Dunnett and Tukey tests (95% CI).

RESULTS

Uterus: GII and GIII differed from GI in all respects; GII vs. GIII, no differences. Urethra: GIII vs. GI: no differences; GII vs. GI, differences in NU and CF; GII vs. GIII, differences in NU and CF.

CONCLUSIONS

Early oral administration of SIE to ovariectomized rats reversed uterine/urethral effects of castration.

Cognitive function in late versus early postmenopausal stage

OBJECTIVES

There are relatively few studies of cognitive performance in the first few postmenopausal years and insufficient data on whether there is differential decline in different cognitive abilities. The aim of the present analysis was to determine the nature of cognitive decline across a range of functions within a period of 5 years from early to late postmenopausal stage.

METHODS

In a cross-sectional study, 189 postmenopausal women, who had experienced a natural menopause, were not taking hormonal medication and had not done so in the previous 12 months, were divided according to their postmenopausal stage into early (stage +1, < or =5 years since the last menstrual period, aged 55.4+/-0.3 years, n=80), or late (stage +2, >5 years since the last menstrual period, aged 59.8+/-0.4 years, n=109) postmenopausal stages. Participants completed a comprehensive battery of tests measuring attention, episodic and semantic memory, planning and mental flexibility. Participants also completed self-ratings of mood, sleepiness and menopausal symptoms.

RESULTS

There were no differences between the groups in their performance in tests of attention, verbal fluency or memory. However, in the two tests of executive function (planning and mental flexibility) the women in the late postmenopausal stage performed significantly worse than the women in the early postmenopausal stage. These differences remained significant when effects of age and IQ were taken into account by analyses of covariance. There were no differences between the groups in their ratings of mood or of habitual sleepiness, or of feeling sleepy at the start of testing. However, by the end of testing the women in the late postmenopausal stage rated themselves as feeling sleepier than did the women in the early postmenopausal stage. The group differences in executive function remained significant when these differences in sleepiness were accounted for.

CONCLUSIONS

Although there were no differences in attention, verbal fluency and memory, executive function was significantly poorer in the late postmenopausal stage women, suggesting that this aspect of cognition deteriorates more rapidly than other functions. This change was independent of change in age, suggesting that hormonal changes between the early and late postmenopausal stages may be responsible.

Cognitive function across the life course and the menopausal transition in a British birth cohort

OBJECTIVE

Despite biological plausibility, relationships between menopause and cognitive function are inconsistent. We investigated whether menopause status and menopause age were associated with general cognitive ability, verbal memory, and visual search speed and concentration in a large cohort of women while considering vasomotor and psychological symptoms, previous childhood and adult measures of cognitive function, lifetime socioeconomic circumstances, educational attainment, lifestyle factors, and chronic diseases.

DESIGN

A nationally representative British cohort of 1261 women born in March 1946 and all aged 53 years at cognitive testing, with prospective information on previous cognitive function, menopausal characteristics, and potential confounders.

RESULTS

There was only weak evidence of the effect of natural menopause on cognitive function and no evidence of any effects of hormone therapy use or hysterectomy status. There was a trend across the phases of the natural menopausal transition (pre-, peri-, and postmenopause) for the National Adult Reading Test (P = 0.005) and search speed and concentration (P = 0.042), with postmenopausal women having the lowest cognitive function, but there was no trend in verbal memory. Variation in vasomotor and psychological symptoms did not explain these trends. In postmenopausal women, there was a positive trend across menopause age for verbal memory (P = 0.004) and a weak positive trend for the National Adult Reading Test (P = 0.052), with women who reached menopause later having higher cognitive function. Previous cognitive function generally explained the associations, which were further weakened by adjusting for socioeconomic and educational confounders. One exception was the association between the natural menopause transition and search speed and concentration, which remained after adjustment for these factors.

CONCLUSION

Menopause adversely affects cognitive function, but this effect may be largely explained by premenopausal cognitive function. These findings suggest that common environmental or genetic factors, operating through long-term or lifelong hormonal mechanisms, may influence the timing of natural menopause and lifetime cognitive function.

A population-based longitudinal study of cognitive functioning in the menopausal transition

BACKGROUND

No longitudinal studies have tracked cognitive performance through the menopausal transition and thus the impact of the transition on cognition, independent of aging, is not known. The authors hypothesized that a decline in cognitive functioning occurs as women progress through the menopausal transition, independent of age, educational level, family income, ethnicity, and baseline self-perceived health.

METHOD

The authors began a population-based, longitudinal study in January 1996 with yearly follow-up interviews. This report includes follow-up through November 2001. The authors randomly selected African American and white women from a census of two contiguous Chicago communities. After screening for eligibility (age 42 to 52 years, premenopausal or early perimenopausal, no exogenous hormone use in the past 3 months, and no hysterectomy), 868 agreed to participate. Women who became pregnant, had a hysterectomy, or began using hormones were censored from that time onward. This study reports on 803 women for whom cognitive assessments were available. The authors assessed working memory (Digit Span Backward) and perceptual speed (Symbol Digit Modalities Test).

RESULTS

Contrary to the hypothesis, the authors found small but significant increases over time during the premenopausal and perimenopausal phases. This trend was not accounted for by chronological age, education, family income, ethnicity, or baseline self-perceived health.

CONCLUSIONS

Transition through menopause is not accompanied by a decline in working memory and perceptual speed.

Allopathic and complementary alternatives to hormone replacement therapy

Management of the menopause is a rapidly growing concern due to the ageing human population. The overall female lifespan has increased over the last century and up to a third of a woman's life is now spent in menopause. To that end, significant attention has been placed on maximising the quantity and quality of life in the menopausal years. The optimal management strategies are ones that are highly flexible and sensitive to an individual's expectations and concerns. Thus, while traditional oestrogen replacement therapy has been in place for > 20 years, there is now a greater interest in alternatives to this modality for those women who cannot or will not use it. This article reviews some of the alternative therapies that are being incorporated both in the allopathic and complementary medicine arenas.

Phytoestrogens in the management of the menopause: up-to-date

Despite the benefits of conventional hormone replacement therapy, some women are not candidates for this treatment and many others choose not to take it. As a result, there is growing interest among patients about natural alternatives. There is some evidence that phytoestrogens may offer protection against a wide range of human conditions, including breast cancer, cardiovascular disease, brain dysfunction, osteoporosis, and menopausal symptoms. The literature on the possible health benefits of phytoestrogens has expanded exponentially since the 1980s, mainly in response to funding initiatives by the U.S. government and soybean industries, and more lately by European and UK Ministries of Food. The physiological effects of phytoestrogens also have created a marketing opportunity that has been used by industry, particularly in soybean-producing countries such as the U.S. and Australia. Nevertheless, clinical applications for phytoestrogens are still in their infancy, and more interventional trials are required to reach definitive conclusions regarding their efficacy and safety, although they appear to represent a promising group of compounds, which may be useful in the future for the treatment of the menopausal syndrome. Also, the lack of clinical data presently available must signal caution in relation to the possible risk of adverse effects.

TARGET AUDIENCE

Obstetricians and Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to identify the various types of phytoestrogens, list the sources of phytoestrogens, and summarize the various effects of phytoestrogens.

A comprehensive approach to the menopause: so far, one size should fit all

Although extensive studies have indicated that the benefits of hormone replacement therapy outweigh the risks, many women and health care providers have concerns about safety and side effects. Many alternative therapies are popular with patients, and menopausal women in the United States spent more than $600 million in 1999 alone purchasing these therapies. Several of the more commonly used alternative therapies for the menopause are critically appraised in this article. For women who choose not to take estrogen, and for those who do, the additional benefits of calcium, vitamin D, exercise, stress reduction, and different dietary and lifestyle adaptations may enhance the quality of life as they age. Although they have the potential for being effective and safe options, there has been limited clinical research for the other alternative therapies. Gynecologists and other health care providers should be aware of the lack of evidence for the effectiveness of most of these therapies when they address patient's questions and concerns. Our information about alternative therapies will increase in the coming years. Ultimately, the growing number of available treatment choices will allow individualization of the treatment. Nevertheless, until prospective studies with prolonged follow-up are conducted to evaluate the risks and benefits of different alternative therapies, hormone replacement therapy, which is better studied, will remain the treatment of first choice, and "one size fits all" will continue to describe the management plan for most peri- and postmenopausal women at least in the near future.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to summarize the various alternatives to hormonal therapy for menopausal symptoms, describe the effects of phytoestrogens in the management of menopausal symptoms, and explain the origin and clinical use of the more common herbal therapies.