Estrogen replacement therapy cardiovascular effects

Observational studies have suggested possible favourable effects of estrogen replacement therapy (ERT) on the risk of coronary heart disease in postmenopausal women. Since elevated plasma cholesterol has been identified as the primary risk factor for cardiovascular disease, investigations have focused on the inverse association between plasma cholesterol concentration and soy protein consumption. The cholesterol-lowering properties of soy have been demonstrated, and a good correlation has been found in... 

Progestins antagonize estrogen s effects on LDL and HDL to a variable extent. However, one large study has shown that the addition of a progestin to estrogen replacement therapy does not influence the cardiovascular risk. 

The effects of HRT on cardiovascular function have been prospectively studied over 1 year in 46 healthy postmenopausal women, mean age 55 years, who took either estrogen replacement therapy alone (n = 23) or... 

One also finds a critical view expressed in the USA, where a survey of the literature up to the end of 1999 concluded that while raloxifene might carry a lesser risk of breast cancer than estrogen replacement therapy, it was also less effective in maintaining bone density, and that as regards cardiovascular risk the estrogenic treatment produced a more favorable outcome (7). 

Cardiovascular System In women, estrogen protects against cardiovascular disease. The protective cardiovascular effects of estrogen include decreased serum LDL cholesterol and increased HDL cholesterol levels, va-sodilatory effect, and antioxidation of LDL cholesterol (Chapter 20). Extensive clinical trials have shown that estrogen replacement therapy of postmenopausal women reduces the risk of heart disease. 

Other published studies, many of which are of limited scope, do not run closely parallel to the above findings from the Women s Health Initiative, and the data on cardiovascular effects remain particularly confusing. However, Beral and colleagues have pointed out optimistically that substantial new data should soon be available from randomized trials of estrogen-alone hormonal replacement therapy versus placebo, although they added that few additional trial data on combined hormone replacement therapy are expected for about a decade (10). They also pointed out that existing randomized trials are too small to provide reliable evidence on some basic matters, including the relative risks of the various compounds in use. 

---