Sex and gender differences in control of blood pressure.

In recent years, the interest in studying the impact of sex steroids and gender on the regulation of blood pressure and cardiovascular disease has been growing. Women are protected from most cardiovascular events compared with men until after menopause, and postmenopausal women are at increased risk of cardiovascular complications compared with premenopausal women. The pathophysiological mechanisms have not been elucidated, but are not likely to be as simple as the presence or absence of oestrogens, since hormone replacement therapy in elderly women in the Women's Health Initiative or HERS (Heart and Estrogen/progestin Replacement Study) did not provide primary or secondary prevention against cardiovascular events. Men are also thought to be at risk of cardiovascular disease at earlier ages than women, and these mechanisms too are not likely to be as simple as the presence of testosterone, since androgen levels fall in men with cardiovascular and other chronic diseases. In fact, many investigators now believe that it is the reduction in androgen levels that frequently accompanies chronic disease and may exacerbate cardiovascular disease in men. In the present review, the roles of sex steroids and gender in mediating or protecting against hypertension and cardiovascular disease will be discussed.