The Role of Sex Hormones in the Cardiovascular System

In developed countries heart disease is the primary cause of death in men and in women over the age of 60. While premenopausal women have a low incidence of cardiovascular disease as compared to men, the mortality among post-menopausal women rises to the same frequency or even exceeds the rates of men (Adams et al., 1995; Fraser et al., 2000; Gray et al., 2001; Wild & Bartholemew, 1988). This significant gender difference is mostly attributed to the beneficial role of estrogens (Collins et al., 1993; Gray et al., 2001). Many studies have suggested that females have reduced incidence of cardiovascular diseases due to the beneficial effects of estrogen on both the lipid profile and on the vasculature. Lately, many new mechanisms are discovered in cardiovascular diseases and research has been focused on the role of both estrogen and testosterone, as well as some other androgens, but also on the estrogen receptor GPER, which shows an important role in the cardioprotection of both, males and females (Deschamps &Murphy, 2009). The sex hormones in the cardiovascular system might be viewed at as biomarkers for cardiovascular health status, as well as by itself, as protective agents against myocardial diseases. The estrogens in premenopausal women are modulating health in the regular menstrual cycle. Testosterone is lacking such cycle activity and is probably more expressed in the physically active population. The effects of testosterone are increasing muscle mass induced by higher physical activity, and higher adrenal and hypophysis activity resulting in potential cardiovascular system damage. However, when testosterone or its derivatives are missused, ventricular hypertrophy, diastolic dysfunction and myocardial stiffening appear and the potential risk for infarction increases (Malkin et al., 2010). The sex hormones, i.e. estrogen, progesterone and androgens and their receptors, ERs, PRs and ARs, have been studied as candidates to mediate sex-specific effects observed in gender related responses of the cardiovascular system and related diseases. Above all estrogen has received major attention, while testosterone is at present studied for its potential beneficial and cardioprotective mechanism of action. However, within several cardiovascular diseases like myocardial infarction, coronary artery disease and other ischemia related diseases, heart failure, ECG gender specific differences, the focus was already turned to the gender related sex hormones differences. These studies presented new approaches and specificities in