Gonadal Function and the Development of Coronary Heart Disease

Cardiovascular and metabolic morbidity after hysterectomy with ovarian conservation: a cohort study

OBJECTIVE

The aim of the study was to determine the long-term risk of cardiovascular disease and metabolic conditions in women undergoing hysterectomy with bilateral ovarian conservation compared with age-matched referent women.

METHODS

Using the Rochester Epidemiology Project records-linkage system, we identified 2,094 women who underwent hysterectomy with ovarian conservation for benign indications between 1980 and 2002 in Olmsted County, Minnesota. Each woman was age-matched (±1 y) to a referent woman residing in the same county who had not undergone prior hysterectomy or any oophorectomy. These two cohorts were followed historically to identify de novo cardiovascular or metabolic diagnoses. We estimated hazard ratios (HRs) and 95% CIs using Cox proportional hazards models adjusted for 20 preexisting chronic conditions and other potential confounders. We also calculated absolute risk increases and reductions from Kaplan-Meier estimates.

RESULTS

Over a median follow-up of 21.9 years, women who underwent hysterectomy experienced increased risks of de novo hyperlipidemia (HR 1.14; 95% CI, 1.05-1.25), hypertension (HR 1.13; 95% CI, 1.03-1.25), obesity (HR 1.18; 95% CI, 1.04-1.35), cardiac arrhythmias (HR 1.17; 95% CI, 1.05-1.32), and coronary artery disease (HR 1.33; 95% CI, 1.12-1.58). Women who underwent hysterectomy at age ≤35 years had a 4.6-fold increased risk of congestive heart failure and a 2.5-fold increased risk of coronary artery disease.

CONCLUSIONS

Even with ovarian conservation, hysterectomy is associated with an increased long-term risk of cardiovascular and metabolic conditions, especially in women who undergo hysterectomy at age ≤35 years. If these associations are causal, alternatives to hysterectomy should be considered to treat benign gynecologic conditions.

Management Strategies for the Ovaries at the Time of Hysterectomy for Benign Disease

Gynecologists performing hysterectomy for benign disease must universally counsel women about ovarian management. The beneficial effect of elective bilateral salpingo-oophorectomy (BSO) on incident ovarian and breast cancer and elimination of need for subsequent adnexal surgery must be weighed against the risks of ovarian hormone withdrawal. Ovarian conservation rates have increased significantly over the past 15 years. In postmenopausal women, however, BSO can reduce ovarian and breast cancer rates without an adverse impact on coronary heart disease, sexual dysfunction, hip fractures, or cognitive function.

Timing of hormone therapy, type of menopause, and coronary disease in women: data from the National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation

OBJECTIVE

The aim of this study was to assess the relationship of the timing of hormone therapy (HT) use with angiographic coronary artery disease (CAD) and cardiovascular disease (CVD) events in women with natural versus surgical menopause.

METHODS

We studied 654 postmenopausal women undergoing coronary angiography for the evaluation of suspected ischemia. Timing and type of menopause, HT use, and quantitative angiographic evaluations were obtained at baseline, and the women were followed for a median of 6 years for CVD events.

RESULTS

Ever users of HT had a significantly lower prevalence of obstructive CAD compared with never users (age-adjusted odds ratio, 0.41 [0.28-0.60]). Women with natural menopause initiating HT before age 55 years had lower CAD severity compared with never users (age-adjusted β [SE] = -6.23 [1.50], P < 0.0001), whereas those initiating HT at age 55 years or more did not differ statistically from never users (-3.34 [2.13], P = 0.12). HT use remained a significant predictor of obstructive CAD when adjusted for a "healthy user" model (odds ratio, 0.44 [0.30-0.73]; P = 0.002). An association between HT and fewer CVD events was observed only in the natural menopause group (hazard ratio [95% CI], 0.60 [0.41-0.88]; P = 0.009) but became nonsignificant when adjusted for the presence or severity of obstructive CAD.

CONCLUSIONS

Using the quantitative measurements of the timing and type of menopause and HT use, earlier initiation of HT was associated with less angiographic CAD in women with natural but not surgical menopause. Our data suggest that the effect of HT use on reduced cardiovascular event rates is mediated by the presence or absence of angiographic obstructive atherosclerosis.

Effect of bilateral oophorectomy on women's long-term health

Bilateral oophorectomy at the time of hysterectomy for benign disease is commonly practiced in order to prevent the subsequent development of ovarian cancer or other ovarian pathology that might require additional surgery. At present, bilateral oophorectomy is performed in 78% of women aged between 45 and 64 years having a hysterectomy, and a total of approximately 300,000 prophylactic oophorectomies are performed in the USA every year. Estrogen deficiency resulting from pre- and post-menopausal oophorectomies has been associated with higher risks of coronary heart disease, stroke, hip fracture, Parkinsonism, dementia, cognitive impairment, depression and anxiety in many studies. While ovarian cancer accounts for 14,800 deaths per year in the USA, coronary heart disease accounts for 350,000 deaths per year. In addition, 100,000 cases of dementia may be attributable annually to prior bilateral oophorectomy. At present, observational studies suggest that bilateral oophorectomy may do more harm than good. In women who are not at high risk of developing ovarian or breast cancer, removing the ovaries at the time of hysterectomy should be approached with caution.

Factors associated with undergoing bilateral salpingo-oophorectomy at the time of hysterectomy for benign conditions

OBJECTIVE

To identify possible factors associated with undergoing bilateral salpingo-oophorectomy (BSO) at the time of hysterectomy among women with benign conditions.

METHODS

This was a cross-sectional analysis using the 2005 Nationwide Inpatient Sample. Women aged 18 years or older who underwent hysterectomy with BSO or hysterectomy only for a benign condition were included. We examined a broad range of factors associated with undergoing BSO in multivariable analyses.

RESULTS

Fifty-two percent of 461,321 hysterectomies included BSO, with a mean age of 49 years compared with 43 years in the hysterectomy-only group (P<.001). The odds of BSO were two times higher in the Midwest and South and 1.67 times higher in the West as compared with the Northeast (P<.001). Women who were uninsured or had Medicaid were more likely to undergo BSO compared with those with private insurance (odds ratio 1.86, 95% confidence interval 1.14-3.04 for "no charge/charity," odds ratio 1.21, 95% confidence interval 1.08-1.35 for Medicaid) Although BSO was more common among white women than African-American, Latina, and Asian women (P<.001), lower income was associated with BSO among African-American and white women only, not among Asian and Latina women (P=.007 for test for interaction). BSO was eight times as likely with a laparoscopic hysterectomy and 12 times as likely with an abdominal hysterectomy compared with a vaginal approach (P<.001). Women who had endometriosis, pelvic infection, or an ovarian cyst were more likely to undergo BSO (P<.001) compared with women who did not have these diagnoses.

CONCLUSION

There is significant nationwide variation in the practice of BSO. Age, route of hysterectomy, and diagnosis at surgery affect BSO rates. Nonclinical factors such as race or ethnicity, insurance status, income, and geographic location are also associated with BSO practice.

LEVEL OF EVIDENCE

II.

Ischaemic heart disease, stroke and total mortality in women--results from a prospective population study in Gothenburg, Sweden

The aims of this study were to determine the prognosis for women with different symptoms and signs indicating ischaemic heart disease and to relate entry characteristics to events of ischaemic heart disease and stroke, and to overall mortality during a 12-year follow-up period. A prospective cohort study was started as a cross-sectional investigation in 1968-69 (1462 participants aged 38-60, participation rate 90.1%). The same sample was re-studied in 1980-81 (1154 participants, participation rate 78.9% of those studied in 1968-69). In addition, a clinical series comprising all women of similar age in Gothenburg with myocardial infarction during the years 1968-70 (47 women) was followed up for 12 years. The 12-year overall mortality rate for women with initial myocardial infarction in the clinical series was 45%. The 12-year overall mortality rates for women who at the time of the initial study either were considered to have angina pectoris or showed electrocardiographic changes indicating ischaemic heart disease at rest or at work were 10%, 17% and 10% respectively (expected figures 7%, 12% and 10%). Twenty-three women (1.6%) developed myocardial infarction during the follow-up period (8 fatal, 15 non-fatal). New symptoms of angina pectoris were recorded in 56 women (4.0%), new electrocardiographic changes indicating ischaemic heart disease in 73 women (6.0%), and new signs of stroke in 13 women (0.9%). Altogether 75 women (5.1%) died during the follow-up period. These five end-points were taken into consideration. Women with previously untreated arterial hypertension were offered control visits during the follow-up period and were prescribed antihypertensive drugs when clinically indicated. In this group of women, hypertension was not a predictor for any of the end-points. No other systematic intervention was carried out. Increased abdominal adiposity, increased serum triglycerides and low peak expiratory flow were independent predictors of at least three of the end-points studied: myocardial infarction, stroke and death. Increased abdominal adiposity was also an independent predictor of angina pectoris. Initial diabetes was an independent predictor of both myocardial infarction and of death. Low energy intake predicted myocardial infarction and electrocardiographic changes indicating ischaemic heart disease. High serum gastrin levels predicted myocardial infarction. Low education and high degree of mental disorder were independent predictors of angina pectoris. Physical inactivity at leisure and physical inactivity at work were independent predictors of stroke and of death, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Oophorectomy as a risk factor for coronary heart disease

OBJECTIVE

The objective of the study was to examine the relationship between bilateral oophorectomy (BSO) and risk of coronary heart disease (CHD).

STUDY DESIGN

We searched PubMed, EMBASE, meeting abstracts, and reference lists for studies that compared women with BSO at the time of hysterectomy with: (1) women with hysterectomy and ovarian conservation, (2) naturally menopausal women, (3) premenopausal women, or (4) women with no history of hysterectomy or BSO but unreported menopausal status. The primary outcome was fatal or nonfatal CHD.

RESULTS

We reviewed 1956 citations. Seven observational studies met inclusion criteria. Heterogeneity among studies precluded formal metaanalysis. Four studies reported BSO increases risk for CHD but only in some subgroups of women or not in fully adjusted multivariate models. Three studies found no increased risk of CHD following BSO, but these studies had significant limitations.

CONCLUSION

The existing evidence is inconclusive to determine the effect of BSO on risk of CHD.

Risk factors for cardiovascular disease in women: relationship to lipid peroxidation and oxidative stress

Many risk factors that promote cardiovascular disease (CVD) have been identified. These include hypertension, hypercholesterolemia, diabetes, decreased estrogen in post-menopausal women, increased homocysteine, and cigarette smoking. It has recently become clear that a mechanism common to these risk factors is oxidative stress. CVD risk factors specific to women are parity, oophorectomy, pre-eclampsia, and menopause. There are several proposed mechanisms to explain these women-specific associations, such as reduced lifetime exposure to estrogen and insulin resistance, but the underlying mechanism is still unclear. One fact that did not receive much attention is the role of the oxidation hypothesis in these reproductive factors-CVD associations. In fact, pregnant, oophorectomized, and post-menopausal women exhibit higher levels of lipid peroxidation than non-pregnant, non-oophorectomized and pre-menopausal women, respectively. We propose that the increased levels of lipid peroxidation during these states are responsible, at least in part, for their increased risk of CVD. This review extends the concept of the oxidation hypothesis of CVD to reproductive risk factors in women. It also addresses the potential role of oxidative stress in the hyperthyroidism-CVD relationship, as hyperthyroidism is a common disorder that most frequently occurs in women. We also discuss how screening human populations for reactive oxygen species (ROS) levels could help identify groups with a high level of ROS that may be at risk of developing CVD.

Hysterectomy prevalence and cardiovascular disease risk factors in American Indian women

OBJECTIVES

We investigated hysterectomy prevalence and associated demographic and reproductive factors among American Indian women. The association between hysterectomy and cardiovascular disease (CVD) risk factors was also examined.

METHODS

Data were from 2689 American Indian women who participated in the first examination of the Strong Heart Study from 1989 to 1992. Odds ratios were estimated for factors related to hysterectomy adjusting for other covariates. The association between hysterectomy and CVD risk factors was examined among 1726 eligible women using analysis of covariance.

RESULTS

Hysterectomy prevalence ranged from 24% to 34% across differing age groups and the percent with oophorectomy among those with a hysterectomy ranged from 43% to 63%. Geographic area, more prior pregnancy losses, more education, and less speaking of the native language were associated with increased hysterectomy prevalence. After adjustment for age, the women who had a hysterectomy with intact ovaries had higher total cholesterol and low-density lipoprotein cholesterol levels than those with a natural menopause.

CONCLUSIONS

American Indian women have comparable hysterectomy prevalence as non-Hispanic white women. Education and native language speaking related to hysterectomy in this population. Hysterectomy alone may relate to unfavorable changes of lipid profile.

Estrogen protection against coronary heart disease: Are the relevant effects of estrogen mediated through its effects on uterus – such as the induction of menstruation, increased bleeding, and the facilitation of pregnancy?

Women in the age group of 20-50 are shown to have much less susceptibility to Coronary Heart Disease (CHD) and other atherosclerotic diseases as compared to men. Exact cause of which is not precisely known and estrogen is constantly shown to be associated with this phenomenon. Improvement of serum HDL concentration and improvement of endothelial functions are some of the proposed mechanisms through which estrogen is believed to mediate this effect. Estrogen therapy however has failed to protect women with bilateral oophorectomy and hysterectomy. Similarly inability of endogenous estrogen to protect women, who have undergone hysterectomy with functioning ovaries from CHD, questions the currently accepted mechanisms through which estrogen brings about these protective effects. Ineffectiveness of estrogen therapy as prophylaxis against CHD in men further questions the credibility of the currently accepted protective mechanisms of estrogen. Estrogen has variety of effects of on uterus, to induce menstruation, to induce bleeding, facilitative role in pregnancy, fetal growth and development. As these physiological effects either directly or indirectly result in loss of cholesterol from cardiovascular compartment, it is proposed that cholesterol-losing effects of estrogen are more important than its presently believed beneficial effects. The small amount that is lost causes movement of cholesterol from atheroma towards plasma and thereby retards the progress of atherosclerosis. These cholesterol-losing effects of estrogen enable women to enjoy freedom from CHD during their reproductive age, as compared to men of comparable age group. Statistical data obtained from blood donors indirectly support the proposed hypothesis.

Testosterone supplemental therapy after hysterectomy with or without concomitant oophorectomy: estrogen alone is not enough

Hysterectomy has the potential for generating serious consequences in terms of health, including two to seven times greater incidence and prevalence of cardiovascular disease, and quality of life, including loss of sexual libido and pleasure. More than a half-million American women undergo hysterectomy every year. Both in premenopausal women and in postmenopausal women, the ovaries are a critical source not only of estrogen but also of testosterone. Even in instances where ovaries have been spared on removal of the uterus, their function may be compromised. Today, women for whom estrogen replacement therapy is not contraindicated are routinely given supplemental estrogen following hysterectomy/oophorectomy. Many women develop and suffer symptoms of testosterone deficiency that go unrecognized and untreated. Testosterone supplemental therapy for women following hysterectomy not only can improve the quality of their lives in terms of sexual libido, sexual pleasure, and sense of well-being but also can--as does supplementary estrogen--contribute to the prevention of osteoporosis. Most importantly, an increasing body of evidence suggests that testosterone may be cardiovascular protective. As testosterone, the most potent anabolic steroid, has some anabolic effect on virtually every tissue in the body, it is likely that supplementing testosterone to physiological levels contributes to health maintenance in as yet undefined ways and that testosterone deficiency in women may be costing more in morbidity and mortality than we know at present.

Reproductive history and cardiovascular disease risk in postmenopausal women: a review of the literature

OBJECTIVES

It is widely believed that oestrogen protects postmenopausal women from cardiovascular disease. It is unknown, however, whether reproductive history, which affects endogenous oestrogen levels during a woman's life, also influences cardiovascular disease risk in postmenopausal women. We present an overview of the studies which investigate the relationship between reproductive history and risk for cardiovascular disease in women.

METHODS

We conducted a Medline search of literature pertaining to age at menarche, age at menopause, parity and gravidity, breast-feeding, and length and regularity of the menstrual cycle in relation to cardiovascular diseases. Data extraction and synthesis were performed by comparing odds ratios and relative risks presented or calculated.

RESULTS

Age at menarche was not found to influence cardiovascular disease risk, while menstrual cycle irregularity was associated with this risk. The studies pertaining to parity presented conflicting results: protection against as well as an increase in the risk of cardiovascular disease were found in parous women. Pregnancy loss appeared to be related to cardiovascular disease risk. Age at menopause proved to be the reproductive factor most clearly related to cardiovascular disease risk.

CONCLUSIONS

Only menstrual cycle irregularity, pregnancy losses, and age at menopause are possibly related to cardiovascular disease risk in postmenopausal women. All reproductive factors need to be studied together in order to assess reproductive history in a proper manner. Research of this kind will be essential if we are to further increase our knowledge regarding the nature of the effects of endogenous oestrogen on cardiovascular disease.

The effect of hysterectomy and endometrial ablation on follicle stimulating hormone (FSH) levels up to 1 year after surgery

OBJECTIVES

In this study the hypothesis was tested, that in premenopausal patients FSH-levels would rise after 'simple hysterectomy'. As endometrial ablation is not supposed to compromise ovarian bloodflow, there would be no such change in ablated patients.

METHODS

Between January 1995 and April 1996, consecutive premenopausal patients with dysfunctional uterine bleeding who were scheduled for hysterectomy or endometrial ablation were asked to participate in the study. Bloodsamples were drawn before surgery, six weeks, six months and one year after surgery. FSH and oestradiol (E2) were assayed. In all patients data about length and weight were collected to calculate Body Mass Index (BMI). Every visit patients filled in a questionnaire, containing questions about typical climacteric complaints, combined in a five-point scale.

RESULTS

Except for a significant difference in preoperative FSH-level between both groups, there were no significant differences regarding age, Body Mass Index (BMI), oestradiol (E2) or the percentage of women with vasomotor complaints. Compared to the preoperative starting level, six weeks, six months and one year after surgery a significant rise in serum FSH in the hysterectomy group, as well as in the ablation group was found. However there was no significant difference in FSH increase between both groups. One third of the patients in both groups had typical climacteric complaints as flushing and nocturnal sweating.

CONCLUSIONS

Assaying serum FSH-levels before and after uterine surgery and comparing hysterectomized patients and patients after endometrial ablation, we found a significant rise in FSH-level up to one year after surgery in both groups postoperatively, indicating impaired ovarian function. There was no difference in FSH-levels between both groups. Therefore major uterine surgery (hysterectomy, ablation) may prelude an earlier onset of menopause.

Hysterectomy, oophorectomy, and heart disease risk factors in older women

OBJECTIVES

This study examined the relation of hysterectomy and oophorectomy to heart disease risk factors.

METHODS

Data were collected and analyzed for 1150 women aged 50 through 89.

RESULTS

Of these women, 21.8% reported hysterectomy with bilateral oophorectomy; 22.1%, hysterectomy with ovarian conservation. Compared with women without hysterectomy, oophorectomized women, especially those 20 or more years postmenopause, had increased lipids, lipoproteins, glucose, and insulin; blood pressures were increased among current estrogen users. Women with hysterectomies with ovarian conservation had similar or more favorable risk factors than nonhysterectomized women.

CONCLUSIONS

Bilateral oophorectomy, but not hysterectomy, may have long-term negative consequences for heart disease risk factors not totally ameliorated by estrogen use.

Reproductive history, socioeconomic status, and self-reported health status of women aged 50 years or older

OBJECTIVES

This paper describes the relationship between self-reported general health status and several facets of reproductive history.

METHODS

We analyzed survey data on a national probability sample of 1341 women aged 50 and older from the Panel Study of Income Dynamics. We used multivariate regression techniques to control for differences in health indices that assessed health status and functioning.

RESULTS

Women with a history of six or more completed pregnancies were found to be disadvantaged in educational attainment, financial resources, and health status compared with women with no or fewer pregnancies. When current sociodemographic factors were controlled, six or more pregnancies were associated with worse general health and worse physical role functioning. When sociodemographic factors and number of births were controlled, among women with at least one delivery, women who had experienced an infant's death reported worse health as measured by all three indices. Women with a first delivery before the age of 18 were more likely to report a functional limitation.

CONCLUSIONS

Women with high parity status, a history of an infant's death, and an early first pregnancy may be at greater risk of poor health in later life.

Ovarian function after hysterectomy in an Irish hospital population

A group of 52 women following hysterectomy with conservation of one or both ovaries was compared with an age-matched control group attending with menstrual irregularity/menorrhagia, in terms of proportions of women with postmenopausal endocrine profiles, and climacteric symptoms. The mean age for the groups was 42 years, and the mean interval between hysterectomy and the time of the study was 3.5 years. Endocrine levels were postmenopausal in six study and two control patients, and this difference was not significant. Vasomotor symptoms were a complaint of 28 (54%) of the study group and 18 (35%) of the control group, while 30 (58%) and 18 (35%) respectively had at least two other non-specific symptoms. In the absence of prospective studies elucidating the effect of hysterectomy on ovarian function, endocrine profiles should be performed in hysterectomised women complaining of symptoms.

Oestrogen receptors and cardiovascular disease

1. Animal and human studies indicate that female sex hormones are protective against the development of coronary atherosclerosis. 2. Experiments on vascular smooth muscle cells suggest a direct effect of oestrogen on vascular tissue. Although oestrogen receptors (ER) in vascular tissues and an association between ER stimulation and physiological effects have been demonstrated, the cellular mechanisms underlying the effects of oestrogen on the arterial wall remain to be defined. 3. Elucidation of the cellular mechanism underlying the effects of oestrogen on vascular smooth muscle will provide insights into coronary atherosclerosis and will provide an opportunity to apply the protective effects of oestrogen to women in older age groups and to the male population.

Risk factors for atherosclerotic aortoiliac occlusive disease

Notwithstanding the difficulties in analysis because of the small number of studies available, patients with aortoiliac atherosclerosis, irrespective of their sex, have a particular "risk profile" that includes tobacco use, young age, diabetes (rare), frequent hypercholesterolemia, and limited atheroma. It must be remembered, however, that most studies have not dealt with the specific risk factors of lower limb arterial disease and the location of disease in the aortoiliac vessels. It is possible that the classical analysis of the vascular risk factors has overlooked one or more major factors such as hyperhomocysteinemia. This underscores the necessity to conduct further prospective studies specifically focused on the various aspects of lower limb and aortoiliac arterial disease in particular.

Number of pregnancies and the subsequent risk of cardiovascular disease

BACKGROUND

Whether increasing parity or gravidity is a risk factor for coronary heart disease has been debated, but the question remains unresolved.

METHODS

We tested the association between the number of pregnancies and a variety of cardiovascular end points in two groups of women who had completed childbearing. One group comprised 2357 women who were followed for 28 years through the Framingham Heart Study, and the other 2533 women followed for at least 12 years through the first National Health and Nutrition Examination Survey National Epidemiologic Follow-up Study (NHEFS).

RESULTS

The rates of coronary heart disease were higher among multigravid women than among women who had never been pregnant, in both the Framingham Heart Study and the NHEFS, but in both studies, the higher rates were statistically significant only in women with six or more pregnancies. For the women in the Framingham Study, the rate ratio adjusted for age and educational level in the group with six or more pregnancies (as compared with women who had never been pregnant) was 1.6 (95 percent confidence interval, 1.1 to 2.2). For the women in the NHEFS, the same adjusted rate ratio was 1.5 (95 percent confidence interval, 1.1 to 1.9). Adjustments for other known cardiovascular risk factors, including weight, did not markedly alter this risk. The rate of total cardiovascular disease was also significantly higher among multigravid women in the Framingham Study than in the women who had never been pregnant.

CONCLUSIONS

In two prospective American studies, having six or more pregnancies was associated with a small but consistent increase in the risk of coronary heart disease and cardiovascular disease. Whether gravidity itself or some other unmeasured factor accounts for the increase in risk that we observed requires further investigation.

A risk-benefit analysis of elective bilateral oophorectomy: effect of changes in compliance with estrogen therapy on outcome

A bilateral oophorectomy at the time of elective hysterectomy is often performed to prevent ovarian cancer. The assumption that endogenous estrogen can be easily replaced with supplemental medication fosters the decision for routine oophorectomy. Published reports on the use of postmenopausal estrogen indicate that compliance is less than perfect. This fact could affect the overall outcome. Decision analysis techniques with Markov cohort modeling were used to evaluate the policy of elective bilateral oophorectomy. Results from studies judged methodologically sound were combined to determine values representing the influence of estrogen on coronary heart disease, breast cancer, and osteoporotic fracture. The decision tree also explicitly incorporated patient compliance. When compliance with estrogen therapy is assumed to be perfect, oophorectomy yields longer life expectancy than retaining the ovaries. When actual drug-taking behavior is considered, retaining the ovaries results in longer survival. This analysis highlights the importance of including the effects of patient compliance with treatment recommendations when the impact of a health policy decision such as prophylactic surgery is assessed.

Differences in apolipoproteins and low-density lipoprotein subfractions in postmenopausal women on and off estrogen therapy: results from the Framingham Offspring Study

The use of estrogens by postmenopausal women has been associated with reduced risk of coronary artery disease (CAD) in some studies, possibly due to favorable effects of estrogens on plasma lipoproteins. In order to examine such effects, we studied 180 postmenopausal women from the Framingham Offspring Study, selected by type of menopause (natural or oophorectopic) and estrogen use. We determined fasting plasma total cholesterol, triglyceride, very-low-density lipoprotein (VLDL) cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and apolipoprotein (apo) A-l and B concentrations, as well as LDL particle size (LDL 1 to LDL 6). Apo A-l levels were significantly (P less than .005) higher, and diastolic blood pressure and glucose levels were significantly (P less than .05) lower in postmenopausal women taking estrogen regardless of type of menopause. HDL cholesterol levels were also higher in women taking oral estrogens, but differences were significant only for the oophorectomized group (P less than .02). Total cholesterol, VLDL cholesterol, and LDL cholesterol levels were significantly lower (P less than .01) in women with natural menopause who were taking estrogens than in women with natural menopause not taking this medication. No significant differences between estrogen users and nonusers were found with regard to triglyceride levels or LDL particle score, in either the natural menopause or oophorectomy groups. These data indicate that estrogen use in postmenopausal women is associated with significantly elevated plasma apo A-l levels and decreased LDL cholesterol concentrations.

Menopause and heart disease. A review

A large number of studies of disparate design are reasonably consistent in demonstrating that women with early bilateral oophorectomy are at increased risk of coronary heart disease. The evidence for an increase in risk among women with a surgical menopause but without bilateral oophorectomy is inconclusive, but such an effect, if any, could plausibly be explained by decreased ovarian function in many of those women as a consequence of the surgery. These findings, taken together with the lack of excess risk in women with bilateral oophorectomy who take replacement estrogen, support the view that the increased risk is due to estrogen deficiency. This view is further supported by the improvement in the lipid profile induced by estrogen replacement therapy in postmenopausal women. Because ovarian function begins to decline well before menopause, and continues to decline after menopause, it is not surprising that the moment of menopause is not associated with an abrupt increase in risk of heart disease. Moreover, some time is required for the adverse changes in coronary risk factors that occur during the climacteric to be reflected in increased rates of coronary disease. Although natural menopause does not cause an immediate increase in risk of heart disease, it does signal a period of increasing risk that is probably related both to age and to estrogen deficiency.

Effects of bilateral oophorectomy on lipoprotein metabolism

The effects of surgical menopause on lipoprotein levels and their time course were studied in 31 premenopausal women who were undergoing hysterectomy and bilateral oophorectomy for non-malignant conditions. Lipoprotein levels were measured before oophorectomy and afterwards at 6 and 12 weeks, then at intervals of 3 months for 18 months. Low density lipoprotein (LDL) cholesterol levels rose significantly (P less than 0.05) in the 6 weeks after operation from a mean of 3.57 (SD 0.66) mmol/l to 4.21 (SD 0.84) mmol/l with no significant changes thereafter. There were no significant changes in cholesterol in the other density fractions or in triglyceride levels. High density lipoprotein (HDL) subfractions were measured in 10 of the women to assess any change in the relative amounts of cholesterol carried on HDL2 and HDL3, since the protective effect of HDL is believed to be conferred by the HDL2 fraction only. No significant change was found in either fraction. The increase in LDL cholesterol would be expected to result in an appreciable increase in the risk of developing coronary heart disease, but cannot wholly account for the increase in cardiovascular disease associated with oophorectomy.

Plasma lipoprotein cholesterol and endogenous sex hormones in healthy young women

Relationships between plasma levels of lipoproteins and sex hormones were studied in 24 healthy premenopausal women with no risk factors for coronary heart disease. The women were carefully selected to remove the effects of other environmental factors, such as smoking, drugs, alcohol, and exercise, which are known to influence lipid metabolism. They all ate precisely the same Western-style diet for 1 to 2 weeks before blood samples were obtained in the follicular phase of their menstrual cycle. After adjusting for other hormones by multiple regression, significant positive partial correlations were seen between high density lipoprotein cholesterol (HDL-C) and protein bound estradiol (r = .57, P = .02), as well as between very low density lipoprotein cholesterol (VLDL-C) and protein bound estradiol (r = .63, p = .01). A significant negative partial correlation was seen between VLDL-C and free estradiol (r = -.65 P = .01). Conversely, low density lipoprotein cholesterol (LDL-C) levels were negatively correlated with protein bound estradiol (r = -.77, P less than .001) and positively correlated with free estradiol (r = .71, P less than .001). No associations between plasma lipoproteins and testosterone were seen; however, androstenedione was positively correlated with VLDL-C (r = .59, P = .01). These findings show a close link between plasma lipoproteins and sex hormones, and may help to explain the lower risk of coronary heart disease in women.

Sex, plasma lipoproteins, and atherosclerosis: prevailing assumptions and outstanding questions

We review the hypothesis that the incidence of coronary heart disease (CHD) is higher in men than in women due to differences in plasma lipoprotein risk factors between the sexes. Men and women appear to be equally susceptible to the effects of lipoprotein risk factors for CHD, and the difference between the sexes in lipoprotein risk factors for CHD appears to be consistent with their being, at least in part, responsible for the sex difference in CHD. This is apparent both when men and women of equal age are compared, and when age-related variations in the sex differences in plasma lipoproteins and CHD are considered. Differences between the sexes in lipoprotein concentrations are still present when sex differences in adiposity, cigarette smoking, physical activity, and diet are taken into account. Evidence relating these sex differences in CHD and lipoproteins to the effects of sex hormones is critically examined. It is commonly accepted that androgens induce changes in lipoprotein concentrations that would predispose towards CHD, whereas estrogens are held to have opposite effects. However, much of the evidence for this comes from studies of changes associated with administration of synthetic gonadal steroids or with changes in gonadal function. Studies of differences in lipoprotein metabolism in normal men and women are extremely limited. In males high-density lipoprotein (HDL) cholesterol levels fall at puberty, correlating with the rise in plasma testosterone concentrations. In females, HDL levels do not change at puberty, despite the rise in estrogen concentrations. Evidence for lipoprotein changes during the menopause, when estrogen levels decline, is equivocal. Similarly, the evidence for an increase in CHD incidence at the menopause is inconclusive. National mortality data indicate that the decreasing sex difference in CHD after 50 years of age is due to a declining rate of increase in men rather than to an acceleration in CHD incidence in women. In men the age-related increase in low-density lipoprotein (LDL) concentrations diminishes beyond 50 years of age, whereas in women the rate of increase remains unchanged. Studies of the effects of gonadectomy are of doubtful relevance in assessing the roles of sex hormones in CHD, and have not been performed with sufficient rigor to provide definitive conclusions.(ABSTRACT TRUNCATED AT 400 WORDS)

Pregnancy-associated inhibition of coronary artery atherosclerosis in monkeys. Evidence of a relationship with endogenous estrogen

We investigated the influence of repeated pregnancy on diet-induced atherosclerosis in cynomolgus monkeys and sought to determine if circulating endogenous reproductive steroid levels were associated with the extent of coronary artery atherosclerosis. At necropsy, females which were pregnant one or more times were found to have coronary artery atherosclerosis which was one-fourth as extensive as that of intact females which had not been pregnant. Extent of coronary artery atherosclerosis correlated positively with mean total plasma cholesterol (Rho = 0.52, p less than 0.01) and inversely with high density lipoprotein (HDL) cholesterol (Rho = -0.48, p less than 0.01) concentrations; both decreased during pregnancy. Additionally, the extent of coronary artery atherosclerosis was found to have a strong inverse association (Rho = -0.66, p less than 0.001) with an index (area-under-the-curve) of magnitude and duration of the pregnancy-induced elevation in plasma 17-beta estradiol concentration. This association could not be explained by an interrelationship between estradiol area-under-the-curve and either plasma total or HDL cholesterol concentrations. There was no relationship between atherosclerosis extent and a similar index of plasma progesterone concentrations. These findings provide evidence for an inhibitory effect of endogenous estrogen on the progression of coronary artery atherosclerosis.

Menopause and the risk of coronary heart disease in women

To determine the relation of menopause to the risk of coronary heart disease, we analyzed data on a prospective cohort of 121,700 U.S. women 30 to 55 years old who were followed from 1976 to 1982. Information on menopausal status, the type of menopause, and other risk factors was obtained in 1976 and updated every two years by mailing questionnaires. Through 1982, the follow-up rate was 98.3 percent for mortality and 95.4 percent for nonfatal events. After we controlled for age and cigarette smoking, women who had had a natural menopause and who had never taken replacement estrogen had no appreciable increase in the risk of coronary heart disease, as compared with premenopausal women (adjusted rate ratio, 1.2; 95 percent confidence limits, 0.8 and 1.8). Again compared with premenopausal women, the occurrence of a natural menopause together with the use of estrogens did not affect the risk (rate ratio, 0.8, 95 percent confidence limits, 0.4 and 1.3). Women who had undergone bilateral oophorectomy and who had never taken estrogens after menopause had an increased risk (rate ratio, 2.2; 95 percent confidence limits, 1.2 and 4.2). However, the use of estrogens in the postmenopausal period appeared to eliminate this increased risk among these women as compared with premenopausal women (rate ratio, 0.9; 95 percent confidence limits, 0.6 and 1.6). These data suggest that, in contrast to a natural menopause, bilateral oophorectomy increases the risk of coronary heart disease. This increase appears to be prevented by estrogen-replacement therapy.

The role of individual differences in lipoprotein, artery wall, gender, and behavioral responses in the development of atherosclerosis

Striking individual differences exist in the response of animals to atherogenic diets. In this communication, we have summarized the accumulated data that relate to a better understanding of this individuality in susceptibility to atherosclerosis. Described herein, are the accumulated data concerning individual differences in the ways in which animals respond to dietary cholesterol. Also contained in this review, are beginning efforts to understand individual differences in susceptibility to coronary artery atherosclerosis at the level of the artery wall ("mesenchymal susceptibility"). We have placed special emphasis on individual differences that exist among cynomolgus macaques in certain psychosocial variables that contribute to individual differences in susceptibility. Among male cynomolgus macaques both status and social condition contribute to these individual differences. Additionally, individual differences in cardiovascular reactivity contribute to varying degrees of atherosclerosis development largely independent of plasma lipid concentrations. Among cynomolgus macaque females, stress-ovarian function relationships have a major influence on the relative degree to which these female animals are protected against diet-induced coronary artery atherosclerosis.

Ovariectomy, social status, and atherosclerosis in cynomolgus monkeys

Evidence is contradictory regarding the effects of natural or surgical menopause on "female protection" against coronary artery atherosclerosis. We evaluated atherosclerosis, plasma lipids, blood pressure, and carbohydrate tolerance in 21 ovariectomized and 23 intact female cynomolgus macaques fed a moderately atherogenic diet for 30 months. We also evaluated the influence of social dominance status, with particular emphasis on a possible relationship with ovarian endocrine function. Atherosclerosis was two to 10 times as extensive in coronary, carotid, and iliaco-femoral arteries of the ovariectomized females; this could be explained, in part, by 15% to 20% increases in total plasma and LDL cholesterol concentrations. Socially dominant intact females were protected against advanced atherosclerotic lesions (plaques) of the coronary arteries, while subordinate females and ovariectomized females were not. Increased susceptibility to advanced coronary artery atherosclerosis in subordinate intact females may have been related in some way to chronic ovarian dysfunction observed in seven of 12 of these individuals. As a group, subordinate intact females also had enlarged adrenal glands, suggestive of mechanisms that may influence atherogenesis independently. The results indicate that, in this species, ovariectomy and chronic ovarian dysfunction related to subordinate social status are associated with a more atherogenic plasma lipid pattern and abolish "female protection" against coronary artery atherosclerosis.

Changes in lipoproteins and subfractions following oophorectomy and oestrogen replacement in peri-menopausal women

Serum cholesterol concentrations in lipoprotein fractions and subfractions were determined in 11 peri-menopausal women both before and after bilateral oophorectomy, as well as 60 days after commencement of oral oestradiol replacement therapy. Pre-operatively, all subjects were found to have normal lipid and lipoprotein concentrations. There was a post-operative increase in the total cholesterol level, which was attributed to a raised very-low-density lipoprotein (VLDL) cholesterol. Changes in high-density lipoprotein (HDL) subfractions HDL-2 and HDL-3 were noted but since these were compensatory little difference in total HDL cholesterol was observed. Following oral oestrogen replacement, the cholesterol level decreased as a result of a drop in both VLDL and low-density lipoprotein (LDL) cholesterol. The oestradiol-induced HDL cholesterol increment reflected an increase in the levels of both HDL subfractions.

Early menopause and the risk of myocardial infarction

We evaluated the relation between age at menopause and the risk of nonfatal myocardial infarction (MI) among 121,964 nurses who responded to a mail questionnaire. Of 279 women who reported having been hospitalized for MI, 123 (44%) were postmenopausal (i.e., no longer menstruating) at the time of hospitalization, compared with 1,859 (33%) of 5,580 age-matched control subjects. Among women who became menopausal because of bilateral oophorectomy, the estimated relative risk of MI increased with decreasing age at menopause, and women who underwent bilateral oophorectomy before age 35 were estimated to have a risk of hospitalization for MI approximately 7.2 times (95% confidence interval, 4.5 to 11.4) that of premenopausal women. Hysterectomy without the removal of both ovaries was only weakly associated with an increased risk. The data support the hypothesis that premature cessation of ovarian function increases the risk of nonfatal MI.

Premenopausal hysterectomy and cardiovascular disease

A premenopausal simple hysterectomy is associated with a threefold increase in the subsequent incidence and prevalence of coronary heart disease during the remaining premenopausal years. During the 10 years following a premenopausal hysterectomy, there is an approximately 4% probability of developing coronary heart disease and a 0.4% probability of dying from it. For every 28 uterine cancer deaths prevented by hysterectomy in 30-year-old women, there is an operative death. To be assured that premenopausal hysterectomies do not cause more deaths from cardiovascular disease than they save by prevention of uterine cancer requires a prospective study of 20,000 women observed until death. Pending further elucidation of this phenomenon, gynecologists should consider advising premenopausal women considering hysterectomy on the risks of coronary heart disease following the procedure.

Biologic and psychosocial risk factors of sudden death from coronary disease in white women

The relation of the risk of sudden death from arteriosclerotic heart disease to psychosocial and biologic factors was studied retrospectively in 64 white women who died suddenly of arteriosclerotic heart disease and in 64 age-related neighborhood control women. All sudden deaths occurred outside the hospital within 24 hours of the onset of symptoms in women who were not incapacitated before death. Women who died suddenly were less often married, exhibited more educational incongruity with their spouses and had fewer children than the control population. Twelve of the 64 women who died suddenly of heart disease and none of the control women had a definite history of psychiatric treatment. The women who died suddenly also smoked more cigarette and consumed greater quantities of alcoholic beverages than age-matched neighborhood control women. Multiple regression analysis revealed that history of psychiatric illness, cigarette smoking, alcohol consumption, educational incongruity and number of children contributed significantly to differences between women who died suddenly of heart disease and control subjects.

Menopause and myocardial infarction

Age and circumstances of menopause (natural or artificial) are detailed in 104 cases of recent myocardial infarction (MI). The results of this study with statistical analysis show no correlation between the age at menopause and the age at onset of MI; so for this study, an early menopause, cannot be considered, whatever circumstances, as a risk factor for coronary heart disease.

Why do women live longer than men?

In the contemporary United States, males have 60 percent higher mortality than females. In Part I, published in the previous issue, we showed that 40 percent of this sex differential in mortality is due to a twofold elevation of arteriosclerotic heart disease among men. Major causes of higher rates of arteriosclerotic heart disease in men include greater cigarette smoking among men; probably a greater prevalence of the competitive, aggressive Coronary Prone Behavior Pattern among men; and possibly a protective role of female hormones. In addition, men have higher death rates for lung cancer and emphysema, primarily because more men smoke cigarettes. In Part II we analyze the other major causes of men's higher death rates: accidents, suicide, and cirrhosis of the liver. Each of these is related to behaviors which are encouraged or accepted more in men than in women in our society--for example, using guns, being adventurous and acting unafraid, working at hazardous jobs and drinking alcohol. We conclude with suggestions for reducing male mortality; for example, by changing the social conditions which foster in men the behaviors that elevate their mortality.

Why do women liver longer than men?

In the contemporary United States, mortality is 60% higher for males than for females. Forty percent of the excess of male mortality is due to arteriosclerotic heart disease, which is more common among men in part because they smoke cigarettes more than women do, and apparently also because they more often develop the competitive, aggressive Coronary Prone Behavior Pattern. Men who do not develop this Behavior Pattern may have as low a risk of coronary heart disease as comparable women. Oophorectomy of young women may increase the risk of coronary heart disease, but administration of female hormones generally does not reduce risk. One third of the sex differential in mortality is due to men's higher rates of suicide, fatal motor vehicle and other accidents, cirrhosis of the liver, respiratory cancers and emphysema. Each of these causes of death is linked to behaviours which are encouraged or accepted more in males than in females: using guns, drinking alcohol, smoking, working at hazardous jobs, and seeming to be fearless. Thus, the behaviors expected of males in our society make a major contribution to their elevated mortality.