Estrogen plus progestin and the risk of coronary heart disease

Coronary heart disease risk reduction in postmenopausal women: the role of statin therapy and hormone replacement therapy

The incidence of coronary heart disease in women rises sharply in the years following menopause, and prescribing of hormone replacement therapy in the belief that it might compensate for the loss of estrogen-mediated cardioprotection is widespread. However, controlled trials have failed to show a beneficial effect of hormone replacement therapy on the incidence of coronary events, and recent evidence suggests that hormone replacement therapy may even have a deleterious effect on primary coronary heart disease prevention. Statins are recommended as first-line treatment for lowering low-density lipoprotein cholesterol levels in women and are extremely valuable in reducing coronary heart disease risk in this group. An awareness of the benefits of appropriate statin treatment, and evidence showing that they can be safely added to hormone replacement therapy prescribed for the relief of menopausal symptoms and osteoporosis, provides the opportunity to optimize clinical outcomes for coronary heart disease among the large and expanding population of postmenopausal women.

Chronic disease prevention: public health potential and research needs

This paper, arising out of an event to honour the statistical and scientific contributions of Professor Peter Armitage, is concerned with research strategies and needs for chronic disease prevention. A few highlights from recent intervention trials for the prevention of cancer, cardiovascular disease, fractures and diabetes is provided, along with a discussion of some settings where intervention trial results seem discrepant with a body of preceding observational data. This background is used to identify research strategies and infrastructure needs for moving this vitally important research area forward, for both chemoprevention and lifestyle modification interventions.

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

PURPOSE OF REVIEW

To review the randomized trials of hormone replacement therapy.

RECENT FINDINGS

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

SUMMARY

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

Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure

The National High Blood Pressure Education Program presents the complete Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Like its predecessors, the purpose is to provide an evidence-based approach to the prevention and management of hypertension. The key messages of this report are these: in those older than age 50, systolic blood pressure (BP) of greater than 140 mm Hg is a more important cardiovascular disease (CVD) risk factor than diastolic BP; beginning at 115/75 mm Hg, CVD risk doubles for each increment of 20/10 mm Hg; those who are normotensive at 55 years of age will have a 90% lifetime risk of developing hypertension; prehypertensive individuals (systolic BP 120-139 mm Hg or diastolic BP 80-89 mm Hg) require health-promoting lifestyle modifications to prevent the progressive rise in blood pressure and CVD; for uncomplicated hypertension, thiazide diuretic should be used in drug treatment for most, either alone or combined with drugs from other classes; this report delineates specific high-risk conditions that are compelling indications for the use of other antihypertensive drug classes (angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, beta-blockers, calcium channel blockers); two or more antihypertensive medications will be required to achieve goal BP (<140/90 mm Hg, or <130/80 mm Hg) for patients with diabetes and chronic kidney disease; for patients whose BP is more than 20 mm Hg above the systolic BP goal or more than 10 mm Hg above the diastolic BP goal, initiation of therapy using two agents, one of which usually will be a thiazide diuretic, should be considered; regardless of therapy or care, hypertension will be controlled only if patients are motivated to stay on their treatment plan. Positive experiences, trust in the clinician, and empathy improve patient motivation and satisfaction. This report serves as a guide, and the committee continues to recognize that the responsible physician's judgment remains paramount.

Old and new cardiovascular risk factors: from unresolved issues to new opportunities

With the aim of identifying areas that may deserve some further thinking the present review deliberately points out controversial issues in cardiovascular research and risk assessment. In the first part of the review general aspects are addressed regarding the evaluation of risk factors. A first point of concern is the frequent practice of combining different vascular events and effects in different vascular beds into a single endpoint. Furthermore, verification of vascular events in clinical reality may be surprisingly inaccurate. Problems in risk assessment also arise from overlapping properties (shared pathophysiological pathways) of traditional risk factors like hypertension, obesity and diabetes. In the second part of the review unresolved issues concerning selected established and emerging risk factors are discussed. The difficulty of establishing causality in cardiovascular disease is addressed, using modification of LDL cholesterol and accumulating evidence for pleiotropic effects of the LDL cholesterol-lowering statins as an example. As an alternative or supplement to the notion of LDL-related cardiovascular risk it is proposed to distinguish between statin-sensitive and statin-insensitive cardiovascular risk. Finally the future prospects of selected new and emerging risk factors like CRP, homocysteine, asymmetrical dimethylarginine (ADMA), oxLDL, and isoprostanes are evaluated. In summary, imprecise terminology and varying definitions of "cardiovascular risk" may lead to a considerable blurring of our current risk estimates, which may also explain some presently controversial issues. With several new risk factors and substantial changes in lifestyle and treatment patterns on the horizon major changes in the hierarchy of risk factors may be inevitable.

Estrogen therapies, lipids, and the heart disease prevention controversy

One of the most highly unexpected reports in recent medical literature was the lack of benefit of estrogen-progestin replacement therapy in cardiovascular disease prevention in postmenopausal women. The ensuing negative view of hormone replacement therapy has now extended to all forms of postmenopausal hormone treatment, including estrogen alone. Is this pessimism justified? A review of the effects of estrogens and progestins on the estrogen-sensitive systems of the body can help explain why combined oral estrogen and low-dose continuous medroxyprogesterone acetate administration may not be the paradigm for all other forms of postmenopausal hormone replacement. Some of these effects include the following: progestins are anti-estrogens, as evidenced in their divergent effects on plasma lipids; not all progestins are equal in their effect on lipids and other physiologic functions; administration of any hormone by mouth is not physiologic; giving estrogen 10 to 15 years postmenopausally may be too late to prevent atherosclerosis. On the other hand, high doses of oral estrogen/progestin in the presence of high cardiovascular risk appear to promote atherosclerosis risk. Given the current evidence the common sense answer to the question of the benefit of estrogen is "it depends." Until these and other points are formally addressed, the hypothesis that estrogen prevents heart disease remains open.

HT

The ongoing challenge to clinicians is to make medical judgments that are suitable for patients as individuals with unique combinations of medical needs. The cancellation of the WHI study's estrogen/progestin arm leaves unanswered questions that will affect clinicians' medical decisions.

Effects of estrogen replacement on metabolic factors that influence physical performance in female hypogonadism

There is a lack of knowledge regarding the effects of estrogens on physical performance. This is related, in part, to the challenge of isolating the effects of estrogens from those of progestins, because levels of both hormones fluctuate across the menstrual cycle, both decline during the menopausal transition, and the administration oh hormones to hypogonadal women typically involves a combination of estrogens and progestins. Some research findings suggest that fluctuations in estrogen levels acutely influence factors that may affect physical performance, such as substrate utilization or maximal aerobic power, but solid evidence is lacking. The simple observation that hypogonadism is not uncommon among elite athletes in some sports suggests that estrogen deficiency does not have a major negative impact on athletic performance. However, chronic hypogonadism may ultimately lead to impaired performance by menas that are not necessarily obvious. For example, chronic estrogen deficiency has potent, deleterious effects on the skeleton that can increase risk for stress fracture and may limit the ability to sustain a high level of physical training. Estrogen deficiency also appears to promote fat accumulation and may accelerate the loss of fat-free mass, and both of these changes in body composition could impair physical performance. There is evidence that hormone replacement attenuates the negative effects of hypogonadism on body composition and bone density, and that effects are mediated primarily by estrogens rather than progestins. Further research is necessary to broaden the understanding of the role of the estrogens in physical performance.