Estrogen Replacement Therapy: Can it Reduce the Risk of Heart Disease?

Estrogen replacement therapy has been used for a long time to treat menopausal symptoms in women. For much of that time, it was believed that one of the benefits of the treatment was that it reduced the risk of heart disease.

This made sense for a number of reasons. One, in the decade after menopause, when there are major changes in hormonal levels, women's risk of heart disease goes up substantially. So the speculation was that if you offset the drop in estrogen, you could stop this increased risk from occurring.

Two, the estrogen replacement therapy increases "good" cholesterol and decreases "bad" cholesterol, and since cholesterol seems to be an important factor in heart disease risk, this appeared to indicate the treatment would help in this area.

Third, multiple observational studies seemed to show that women who underwent the treatment were less likely to develop heart disease than women who did not.

Still, the evidence was not conclusive, and there were a minority of physicians who remained unconvinced.

So larger, much more expensive, randomized, blinded clinical trials were conducted that controlled for other factors. The result? To most people's surprise, the hypothesis that estrogen replacement therapy lowered the risk of heart disease failed.

Interpretations of the results are not unanimous, and additional studies and research continue to be conducted, but it now appears that estrogen taken in conjunction with progestin (a synthetic form of progesterone) actually increases the risk of heart disease, while estrogen taken alone has either minimal benefits for heart disease or none.

If further research reveals any heart disease benefits at all to any version of estrogen replacement therapy for menopausal women, they are likely to be tiny, and certainly dwarfed by other actions people could take such as quitting smoking, maintaining a healthy weight, and exercising.

Which is not to say that doctors no longer recommend estrogen replacement therapy in any cases. The purported effects on heart disease were merely one of the reasons the treatment was used. Doctors still selectively recommend short-term estrogen replacement therapy for some of their patients for the relief of menopausal symptoms, especially in women who experience premature menopause or premature ovarian failure before age 40.

But certainly weighing the costs and benefits in a given case has been made a lot more complicated with the new evidence reversing the previous majority medical beliefs about estrogen replacement therapy and heart disease.

Sources:

Richard N. Fogoros, "Hormone Replacement Therapy and Heart Disease." About.com.
"Hormone Replacement Therapy and Heart Disease." Cleveland Clinic.
"Hormone Therapy: Is it Right for You?" Mayo Clinic.