Estrogen patch versus the pill
When a major study of hormone replacement therapy showed that it increased the risks of heart disease and breast cancer, many women went cold turkey, leaving some of them with almost intolerable hot flashes and night sweats. Now a small new study suggests there may be a safer way to relieve their menopausal symptoms.
In what is likely to be a wave of studies looking at alternatives to oral hormone replacement, researchers found that estrogen patches minimize one risk factor for heart attack and stroke that’s associated with the pills.
Past studies had shown that both estrogen and estrogen-progestin combination pills boosted levels of C-reactive protein, an indicator of inflammation used to predict cardiovascular problems in healthy women. And last summer, researchers halted the large, federally funded Women’s Health Initiative after finding that women who took hormone pills containing estrogen plus progestin raised their risks of several diseases.
The latest study found that estrogen pills more than doubled blood levels of C-reactive protein but an estrogen skin patch had no effect on levels of that protein, even when given at higher doses than the pills.
The study’s lead author said researchers still need to understand what it is about oral estrogen that’s increasing cardiovascular risks for women.
In the meantime, “the estrogen patch is something they can take without having to worry about an increase in CRP,” said Dr. Wanpen Vongpatanasin, an assistant professor of internal medicine at the University of Texas Southwestern Medical Center in Dallas. Although the study was short, she said, doctors have observed that for a couple of study subjects who remained on the patch a year or two, levels of the inflammatory protein have stayed “exactly the same.”
The federally funded study, published in the current issue of the Journal of the American College of Cardiology, also found that women using an estrogen patch had lower levels of a protein believed to play a role in reducing inflammation, called insulin-like growth factor, or IGF-1.
According to Vongpatanasin, oral estrogen is metabolized through the liver, where it’s converted into a less active form of estrogen before reaching the bloodstream, so doses need to be high to assure a sufficient amount of the hormone reaches the bloodstream.
But because the patch allows estrogen to be absorbed directly into the bloodstream, it can be given in lower doses. The patch lessens the amount of estrogen reaching the liver, where both C-reactive protein and the protective insulin-like growth factor are made.
In the study, researchers in Texas and at the UC Davis Medical Center in Sacramento randomly assigned 21 post-menopausal women to eight-week cycles of three combinations of pills and patches. In one cycle, they got 100 micrograms of estrogen through a patch, along with a dummy pill; in another, a .625-milligram estrogen pill with a placebo patch, and in the third, a placebo patch and placebo pill.
