Abstract
Cardiovascular disease is the leading cause of death in women and claims the lives of more than half a million women every year. Hypertension is one of the most prevalent and powerful contributors to atherosclerotic cardiovascular disease. Hypertension affects more men than women until 55 years of age, but after age 55, the percentage of women is higher. Estrogen deficiency has been linked to the rapid increase in cardiovascular disease in women who have undergone natural or surgical menopause. Hormone replacement therapy (HRT) has been shown to decrease the incidence of cardiovascular disease and, in some studies, to reduce blood pressure in postmenopausal women. However, little information is available on the effects of HRT on blood pressure in hypertensive postmenopausal patients. The cardioprotective effects of estrogens are not completely understood but may involve direct effects on blood vessels through modulation of endogenous vasoconstrictors and vasodilators and through reductions in serum lipoprotein and cholesterol levels. Experimental evidence suggests that estrogen increases the biological actions of nitric oxide and decreases the actions of angiotensin. After menopause, loss of the vascular protective effects of estrogens may unmask a population of women particularly prone to hypertension who would be at higher risk for cardiovascular disease.