Hormone replacement therapy and risk of acute myocardial infarction : a review of the literature

Unique cardiometabolic factors in women that contribute to modified cardiovascular disease risk

Major risk factors of cardiovascular disease (CVD) include hypertension, obesity, diabetes mellitus and metabolic syndrome; all of which are considered inflammatory conditions. Women are disproportionately affected by inflammatory conditions, with sex differences emerging as early as adolescence. Hormonal fluctuations associated with reproductive events such as menarche, pregnancy and menopause, are hypothesized to promote a pro-inflammatory state in women. Moreover, women who have experienced inflammatory-type conditions such as polycystic ovarian syndrome (PCOS), gestational diabetes or pre-eclampsia, have a cardiometabolic phenotype that pre-disposes to increased risk of myocardial infarction, stroke and coronary heart disease. Women with no notable CVD risk factors are often relatively protected from CVD pre-menopause; but overtake men in risk of major cardiovascular events when the cardiovascular protective effects of oestrogen begin to wane. Sex differences and female-specific factors have long been considered challenging to study and this has led to an underrepresentation of females in clinical trials and lack of female-specific data from pre-clinical studies. However, there is now a clear prerogative to include females at all stages of research, despite inherent complexities and potential variability in data. This review explores recent advancements in our understanding of CVD in women. We summarise the underlying factors unique to women that can promote CVD risk factors, ultimately contributing to CVD burden and the emerging therapies aimed to combat this.

Scaling up of physical activity interventions in Brazil: how partnerships and research evidence contributed to policy action

The global health burden due to physical inactivity is enormous and growing. There is a need to consider new ways of generating evidence and to identify the role of government in promoting physical activity at the population level. In this paper, we summarize key findings from a large-scale cross-national collaboration to understand physical activity promotion in Brazil. We describe the main aspects of the partnership of Project GUIA (Guide for Useful Interventions for Activity in Brazil and Latin America) that sustained the collaborative effort for eight years and describe how the evidence gathered from the collaboration triggered political action in Brazil to scale up a physical activity intervention at the national level. Project GUIA is a cross-national multidisciplinary research partnership designed to understand and evaluate current efforts for physical activity promotion at the community level in Latin America. This example of scaling up is unprecedented for promoting health in the region and is an example that must be followed and evaluated.

Gender differences in endothelial function and inflammatory markers along the occurrence of pathological events in stroke-prone rats

Spontaneously hypertensive stroke-prone rats (SHRSP) feature an established model for human cerebrovascular disease. SHRSP, kept on a high-salt permissive diet (JPD), develop hypertension, renal and brain damage. In this report we compared the behavior of female and male SHRSP regarding the main aspects of their pathological condition. Brain abnormalities, detected by magnetic resonance imaging, developed spontaneously in males after 42+/-3 days, in females after 114+/-14 days from the start of JPD. Survival was >3-fold longer for females than for males. The development of brain damage was preceded, in both genders, by an inflammatory condition characterized by the accumulation in serum and urine of acute-phase proteins. The increase in thiostatin level was significantly lower and delayed in female in comparison to male SHRSP. During JPD female and male SHRSP developed massive proteinuria, its worsening being significantly slower in females. The alterations of vasculature-bound barriers in kidney and brain were connected with endothelial dysfunction and relative deficiency in nitric oxide (NO). In thoracic aortic rings, basal release of NO was significantly higher in female than in male SHRSP, both if receiving and if not receiving JPD. The gender differences in SHRSP thus appear to be connected to a more efficient control in females of inflammation and of endothelial dysfunction.

Drug-Induced Cardiovascular Disorders

As the variety and range of pharmaceutical agents available to the medical profession continues to expand, one unavoidable effect will be an increase in drug-induced disease, including cardiovascular disorders. However, given the high rates of cardiovascular disease and prevalence of recognised cardiovascular risk factors in the population, it is sometimes impossible to conclusively attribute any individual patients' ill health to one particular drug. As a result, the relationship between drugs and cardiovascular disease is often difficult to quantify. This review discusses specific forms of drug-induced cardiovascular disease such as heart failure, left ventricular systolic dysfunction, hypertension and arrhythmia. Suspected culprit drugs for all disorders are highlighted. Specific attention is given to certain drug groups with a strong association with one or more forms of cardiovascular disease: these include anthracyclines, antipsychotics, NSAIDs and cyclo-oxygenase 2 inhibitors. Additionally, advice is offered on how physicians might distinguish drug-induced cardiovascular disorders from other aetiologies.

Myocardial infarction risk and hormone replacement: Differences between products

OBJECTIVES

To establish the risk of myocardial infarction (MI) in users of hormone replacement therapy (HRT) compared with non-users and to compare the risk between different HRT regimens.

METHODS

A population-based cohort and case-control study, and a case-control study nested within a cohort of HRT users, using the UK General Practice Research Database. Differences between HRT regimen, mode of administration and duration and recency of use were examined whilst adjusting for confounding.

RESULTS

In the cohort and case-control study, 4537 cases of MI were identified in 2.62 million observed women years, cases were age-matched to 27,220 controls. In both studies, current and past HRT use were associated with reduced risk estimates for MI compared with no prior use. MIs were less likely to be fatal amongst women who had used HRT than amongst never users (OR(adj) 0.58; 95% CI 0.45-0.75). No difference in risk was seen between current and past use, oral and transdermal HRT or between different regimens (p>0.44). In the nested study, no difference was found in the association with MI risk between different oestrogen-progestogen combinations or between different combinations and tibolone. Unopposed oestrogen use was not associated with a decrease in risk compared with combined HRT.

CONCLUSIONS

These results are consistent with previous observational studies in supporting the hypothesis that use of postmenopausal HRT is associated with a decrease in risk of acute myocardial infarction (AMI). Case fatality differed between HRT users and non-users, suggesting a protective effect of HRT. This study does not demonstrate a difference between regimens.

An overlooked connection: serotonergic mediation of estrogen-related physiology and pathology

BACKGROUND

In humans, serotonin has typically been investigated as a neurotransmitter. However, serotonin also functions as a hormone across animal phyla, including those lacking an organized central nervous system. This hormonal action allows serotonin to have physiological consequences in systems outside the central nervous system. Fluctuations in estrogen levels over the lifespan and during ovarian cycles cause predictable changes in serotonin systems in female mammals.

DISCUSSION

We hypothesize that some of the physiological effects attributed to estrogen may be a consequence of estrogen-related changes in serotonin efficacy and receptor distribution. Here, we integrate data from endocrinology, molecular biology, neuroscience, and epidemiology to propose that serotonin may mediate the effects of estrogen. In the central nervous system, estrogen influences pain transmission, headache, dizziness, nausea, and depression, all of which are known to be a consequence of serotonergic signaling. Outside of the central nervous system, estrogen produces changes in bone density, vascular function, and immune cell self-recognition and activation that are consistent with serotonin's effects. For breast cancer risk, our hypothesis predicts heretofore unexplained observations of the opposing effects of obesity pre- and post-menopause and the increase following treatment with hormone replacement therapy using medroxyprogesterone.

SUMMARY

Serotonergic mediation of estrogen has important clinical implications and warrants further evaluation.

Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this new feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest will be abstracted monthly regarding a broad scope of topics.