Benefit/risk of estrogen therapy in cardiovascular disease: current knowledge and future challenges

Clinical significance of minor nonspecific ST-segment and T-wave abnormalities in asymptomatic subjects: a systematic review

The purpose of the study is to examine the prevalence and significance of minor nonspecific ST-segment and T-wave abnormalities (NSSTTA) in the prediction of future cardiovascular disease (CVD) events. Minor NSSTTA are commonly encountered in clinical practice. To date, there have been no systematic reviews focusing on the prevalence and prognostic importance of these findings. Literature searches of MEDLINE (1966-2005) were supplemented with searches of bibliographies from key articles. We focused on isolated minor NSSTTA in healthy middle-aged or elderly populations, including men, women, blacks, and whites, and the association of isolated minor NSSTTA with incident cardiovascular and coronary events. Isolated minor NSSTTA are common in middle-aged white men (ranging from 3.6% to 10.3%), and seem to be even more prevalent in women, blacks, and the elderly. In the 3 studies that examined isolated minor NSSTTA, the multivariable-adjusted hazard ratios for coronary mortality ranged from 1.24 to 1.66. Although gender, race, and age-specific differences in the prognostic significance of minor NSSTTA are not clear because of limited data, minor NSSTTA in asymptomatic patients are an important risk factor for coronary and cardiovascular mortality, independent of traditional risk factors. Minor NSSTTA are prevalent in asymptomatic individuals, and they confer increased risk for CVD and coronary heart disease (CHD), independent of traditional risk factors. Future studies with standardized methodology are needed to elucidate the physiological significance of minor NSSTTA and to further describe gender, race, and age-related differences in the prevalence and prognostic significance of minor NSSTTA.

Patients' willingness to pay for pharmacist-provided menopause and hormone replacement therapy consultations

OBJECTIVE

To determine what women would be willing to pay for pharmacist-provided menopause and hormone replacement therapy consultations and the relationship between willingness to pay (WTP) and patients' perceptions of importance of resolving menopausal symptoms, their satisfaction with physician services, their perceptions of pharmacists' abilities, and income.

METHODOLOGY

A convenience sample of 203 adult women using medications to treat menopause was recruited by their pharmacists. A self-administered survey was used to address the study objectives. The contingent valuation method was used to assess WTP in 4 scenarios (ie, 50% and 100% improvement in symptoms after a half-hour initial and a half-hour follow-up visit, respectively). Logistic regression analyses were used to assess the relationship between WTP and the independent variables.

RESULTS

Two hundred and three surveys were returned resulting in a response rate of 41%. Across all 4 scenarios, at least 85% of women surveyed were willing to pay a minimum of 20 US dollars for pharmacist-provided menopause and hormone replacement therapy services. Respondents were willing to pay a median of 40 US dollars (for both 50% and 100% improvement) per half-hour for initial consultations, and 20 US dollars and 40 US dollars (50% and 100% improvement, respectively) per half-hour for follow-up consultations. Regression analyses revealed that across all 4 scenarios, patients' perceptions of pharmacists' abilities and income were significantly and positively (P < .05) related to WTP for menopause and hormone replacement therapy counseling.

CONCLUSION

This study showed that most women surveyed were willing to pay for pharmacist-provided hormone replacement therapy and menopause counseling services and that the WTP amounts increased as patients' perceptions of pharmacists' abilities and income increased. If pharmacists can effectively educate the public about their capabilities and expertise, they may discover that they have a new niche opportunity.

Effects of ovariectomy and 17 beta-oestradiol replacement on [Ca2+]i in female rat cardiac myocytes

1. The present study investigated the effects of ovariectomy (OVX) and 17beta-oestradiol replacement on [Ca2+]i in rat freshly isolated cardiac myocytes. 2. Myocytes were isolated from the hearts of sham, OVX and OVX + 17beta-oestradiol-replaced female rats by enzymatic digestion with collagenase. Changes in [Ca2+]i in response to varied extracellular [Ca2+] were measured using the Ca2+-sensitive dye fura-2, with the contractile responses of each cell measured as cell shortening. 3. Increasing extracellular [Ca2+] resulted in increased [Ca2+]i in all three groups. Peak [Ca2+]i and the amplitude of the Ca2+ transient were significantly greater (P < 0.01) in cells from OVX animals compared with cells from both sham and 17beta-oestradiol-replaced OVX animals. 4. The time-course of decay of the Ca2+ transient was significantly faster (P < 0.02) in OVX cells compared with both sham and 17beta-oestradiol-replaced cells. In addition, time to 50% relaxation was significantly faster (P < 0.04) and extent of shortening significantly greater (P < 0.01) in OVX cells than in either sham or 17beta-oestradiol cells. 5. These data demonstrate clear differences in peak [Ca2+]i and the amplitude of the Ca2+ transient between OVX female rat cardiac myocytes compared with intact and 17beta-oestradiol-replaced OVX female rat cardiac myocytes. This suggests that oestrogen may play a long-term role in limiting Ca2+ entry into the cardiac myocyte.

Cardiac norepinephrine release: modulation by ovariectomy and estrogen

Previously, we have demonstrated that in contrast to male rats, female rats do not show an age-related reduction of depolarization-elicited norepinephrine (NE) release from cardiac synaptosomes (resealed nerve terminals). These results suggest that sex hormones such as estrogen may modulate NE release from cardiac synaptosomes prepared from female rats. The present study was designed to test the hypotheses that long-term estrogen depletion, resulting from ovariectomy, and estrogen replacement alters depolarization-elicited NE release from cardiac synaptosomes. Female F344 rats were divided into two groups, one of which underwent bilateral ovariectomy, whereas the other underwent a sham operation. Three ovariectomized subgroups received daily injections of conjugated equine estrogens, delta8,9-dehydroestrone or 17 alpha-dihydroequilenin. Another ovariectomized control subgroup and the sham-operated animals received daily injections of vehicle. After 90 or 270 days of treatment, the animals were sacrificed. Cardiac synaptosomes were prepared from each heart, incubated with [(3)H]-NE, and used to evaluate NE release capacity by exposure to 50 mM K(+). The effectiveness of the ovariectomy and the estrogenic actions of the test compounds was confirmed by evaluating vaginal smears, determining uterine weights, and measuring serum luteinizing hormone (LH) concentrations. Ovariectomy (after both 90 and 270 days) significantly increased depolarization-induced NE release compared with sham-operated rats. Treatment with all three estrogenic preparations reduced NE release in ovariectomized rats to values similar to those observed in sham-operated animals. Interestingly, NE release rates from rats treated with conjugated estrogens for 270 but not 90 days were significantly below that observed in age-matched sham animals. These results demonstrate that estrogen modulates depolarization-elicited NE release from cardiac nerve terminals. Such modulation may represent a protective action by estrogen at the cardiac synapse.

Gender influences [Ca(2+)](i) during metabolic inhibition in myocytes overexpressing the Na(+)-Ca(2+) exchanger

BACKGROUND

The Na(+)-Ca(2+) exchanger (NCX) may contribute to Ca(2+) overload and injury in ischemic cardiomyocytes. Recently, NCX overexpression was reported to increase ischemia/reperfusion injury in male and oophorectomized female but not in female mice. We therefore measured the effects of gender and estrogen on [Ca(2+)](i) and [Na(+)](i) during metabolic inhibition (MI) in myocytes from wild-type (WT) and transgenic (TG) mice overexpressing NCX.

METHODS AND RESULTS

Flow cytometry was used with fluo 3 for [Ca(2+)](i) and sodium green for [Na(+)](i) measurements. Male TG mouse myocytes had higher [Ca(2+)](i) after 30 minutes of MI (1086+/-160 nmol/L, n=8) than male WT (688+/-104 nmol/L, n=9, P=0.01). The increase in [Ca(2+)](i) during MI induced by NCX overexpression in female myocytes was not significant, however (TG 552+/-62 nmol/L, n=9; WT 426+/-44 nmol/L, n=7). The magnitude of rise in [Ca(2+)](i) during MI was greater in male than female myocytes. KB-R7943, an NCX inhibitor, abolished the effect of NCX overexpression but did not totally eliminate the effect of gender on [Ca(2+)](i) during MI. NCX current density and basal Na(+) pump function were not influenced by gender. The rise in [Na(+)](i) during MI was greater in male than in female myocytes. Estrogen attenuated the increase in [Ca(2+)](i) and [Na(+)](i) in male myocytes during MI and abolished the gender difference in [Na(+)](i) during MI.

CONCLUSIONS

Increased expression of NCX results in a more marked rise in [Ca(2+)](i) during MI in male than in female mouse myocytes. This gender difference appears to be mediated in part by an inhibitory effect of estrogen on the rise in [Na(+)](i), an NCX modifier, during MI.

Gender and vascular reactivity

Estrogen receptors are found on vascular endothelial and smooth muscle cells; their expression is influenced by exposure to the hormone. Estrogen receptors influence non-genomic events, which are rapid in onset and genomic events, which are longer acting responses. Estrogens affect vascular tone indirectly by modulating release of endothelium-derived vasoactive factors and directly by modulating intracellular calcium in vascular smooth muscle cells. Estrogens indirectly affect thrombotic events and inflammation by altering platelet aggregation and leukocyte adherence and migration, respectively. Estrogens also influence production of mitogens which, when released at sites of vascular injury, affect vascular remodeling. Although estrogens initiate vascular responses, genomic sex may influence and/or limit expression of estrogen receptors and therefore actions of sex steroid hormones throughout the vasculature.

An analysis of breast cancer coverage in selected women's magazines, 1987-1995

PURPOSE

Women's magazines are a significant source of health information for many women, but there is some concern that the media may misrepresent a woman's risk of breast cancer. This review analyzes breast cancer articles in selected women's magazines to determine if the information presented is accurate and balanced.

SEARCH METHODS

For the years 1987 to 1995, the quantity and content of breast cancer articles were examined in four popular women's magazines and three magazines with a large African-American audience. Fifty-nine lead factual breast cancer articles were analyzed for the information presented on prevention measures, risk factors, incidence/mortality statistics, and lifetime risk. The age at diagnosis for women featured in these articles was also determined.

SUMMARY OF IMPORTANT FINDINGS

Breast cancer was the topic of 34.9% of the 585 cancer articles published in these seven magazines. Mammography screening guidelines were recommended in 68% of articles that discussed prevention; 66% presented the American Cancer Society guidelines. Risk factors for breast cancer were reported as age greater than 50 in 41% and family history in 78% of the articles that discussed risk factors. Twenty articles used the lifetime risk statistic of developing breast cancer; six explained what this statistic means. The average age of diagnosis for women featured in the articles was 40.5.

MAJOR CONCLUSIONS

The proportion of breast cancer articles to all cancer articles in these magazines (34.9%) was similar to breast cancer incidence (32.2%) but was higher than its contribution to either female cancer mortality (17.2%) or overall female mortality (4.0%). Magazines that targeted the African-American audience had fewer breast cancer articles than the other four magazines. Risk factors for breast cancer were not discussed in proportion to their impact on risk. The popular lifetime risk statistic was not explained in the majority of cases where it was presented. The average age of diagnosis for the women featured in these articles was far below the median age of diagnosis of 65. Thus, magazine reports may be contributing to women's misunderstanding of their true breast cancer risk.

Increased expression of the cardiac L-type calcium channel in estrogen receptor-deficient mice

Steroid hormones control the expression of many cellular regulators, and a role for estrogen in cardiovascular function and disease has been well documented. To address whether the activity of the L-type Ca2+ channel, a critical element in cardiac excitability and contractility, is altered by estrogen and its nuclear receptor, we examined cardiac myocytes from male mice in which the estrogen receptor gene had been disrupted (ERKO mice). Binding of dihydropyridine Ca2+ channel antagonist isradipine (PN200-110) was increased 45.6% in cardiac membranes from the ERKO mice compared to controls, suggesting that a lack of estrogen receptors in the heart increased the number of Ca2+ channels. Whole-cell patch clamp of acutely dissociated adult cardiac ventricular myocytes indicated that Ca2+ channel current was increased by 49% and action potential duration was increased by 75%. Examination of electrocardiogram parameters in ERKO mice showed a 70% increase in the QT interval without significant changes in PQ or QRS intervals. These results show that the membrane density of the cardiac L-type Ca2+ channel is regulated by the estrogen receptor and suggest that decreased estrogen may lead to an increase in the number of cardiac L-type Ca2+ channels, abnormalities in cardiac excitability, and increased risk of arrhythmia and cardiovascular disease.

Controversies surrounding estrogen use in postmenopausal women

OBJECTIVE

To provide an overview of controversies regarding the use of estrogen in postmenopausal women.

DATA SOURCES

A MEDLINE search was conducted to identify pertinent literature published since 1990. Recently published textbooks devoted to the subjects of menopause and women's health were also reviewed, particularly their bibliographies. The bibliographies of selected review articles were also reviewed.

STUDY SELECTION

Due to the vast amount of literature, only the most relevant published studies were reviewed. Review articles and book chapters authored by researchers of international reputation were also reviewed.

DATA EXTRACTION

Identified studies from the primary literature and selected reviews were carefully reviewed. Information regarding the use of estrogen in postmenopausal women was extracted. Particular attention was given to areas of controversy commonly dealt with in the lay media.

DATA SYNTHESIS

The number of postmenopausal women in the US will approach 60 million in the next decade. Despite numerous potential benefits, many women elect to not take estrogen due to fear of cancer or poor understanding of the long-term consequences of menopause and the beneficial effects of estrogen replacement therapy. Many women rely on the news media for information about hormone therapy and subsequently become confused regarding the benefits and risks. Estrogen relieves climacteric symptoms such as hot flushes and symptoms related to genitourinary tissue atrophy. Outcomes from controlled clinical trials are lacking, but numerous epidemiologic studies document clinically significant decreases in cardiovascular disease and osteoporotic morbidity and mortality. Unopposed estrogen increases the risk for endometrial cancer, but addition of a progestin for at least 10 days per cycle effectively reduces this risk to that of women who do not take estrogen. The association between postmenopausal estrogen use and breast cancer remains controversial, despite the results of numerous observational studies. This uncertainty regarding estrogen replacement and breast cancer risk can actually be reassuring when placed in proper perspective.

CONCLUSIONS

Until some of the controversies surrounding postmenopausal hormone use are resolved, an objective discussion with a knowledgeable healthcare professional regarding the potential benefits and risks will help women make informed decisions regarding estrogen replacement therapy in the postmenopausal years.