Cardioprotective effects of ovarian hormones and the HERS in perspective.

The increased population of women in menopause living in the industrialized countries is associated with an increase of diseases which are dependent or facilitated by a state of estrogen deficiency such as cardiovascular and cerebrovascular diseases. Several studies have shown that estrogen replacement therapy reduces the occurrence of coronary and may be of cerebrovascular disease by nearly 50% in treated women compared to non-users. These findings are supported by the evidence that estrogens have a beneficial effect on cholesterol metabolism and deposition, contributing to the inhibition of atherosclerotic plaque formation in arterial walls as well as a direct effect on the vessel wall. Progestins may, in some cases, counteract the beneficial effect of estrogens upon cardiovascular functions. More androgenic progestins may have a detrimental effect upon vascular reactivity while less androgenic progestins seem not to reduce the beneficial effect of estrogens. Of interest, continuous combined administration of hormone replacement therapy seem to be preferable for women with coronary artery disease or for those with increased cardiovascular risk. Case-control and cohort studies have shown that estrogen progestin therapy is associated with a significant reduction of cardiovascular mortality and morbidity. The HERS study has added critical data regarding the cardioprotective effect of hormone replacement therapy in elderly women with proven coronary artery disease. Because of the several methodological and statistical flaws of the HERS study, further studies are warranted to evaluate the effect of hormone replacement therapy on cardiovascular prognosis. Large scale randomized studies will evaluate the effect of estrogen and estrogen-progestin replacement therapy upon cardiovascular events in menopausal women. Until completion of these studies hormone replacement therapy in women with increased cardiovascular risk should be seen with no enthusiasm but also with no fear.