Postmenopausal hormone replacement therapy, coronary heart disease and plasma lipoproteins.

This review outlines the changes in serum lipoprotein (Lp) concentrations at the menopause. The effect of hormone replacement therapy with estrogen and a variety of progestogens is illustrated by a number of recent studies. Analysis of the effects of estrogen replacement in the primary prevention of coronary heart disease (CHD) is discussed. During the last 4 years, there have been 4 observational studies of the use of estrogen in postmenopausal women with CHD as assessed by coronary angiography. In all of these studies, estrogen has been associated with a reduction in CHD, most strikingly in a study of survival over 10 years. However, there is an overwhelming need for a randomised controlled trial of estrogen for secondary prevention. The role of estrogen in the treatment of type II hyperlipoproteinaemia has been recognised, and a study describing its effect is discussed. Again, there is need for data from well controlled clinical trials to clearly establish the benefits of estrogen therapy. A further aspect for investigation is a study of the non-lipoprotein-mediated effects of estrogen, particularly those on vasomotion. Finally, the intriguing effects of both androgenic and estrogenic steroids on Lp(a) are discussed.