HRT Dosing May Determine Risks, Benefits

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According to Rajat Sethi, assistant professor of pharmaceutical sciences at the Texas A&M Health Science Center Irma Lerma Rangel College of Pharmacy in Kingsville, these doses seem to be in a range comparable to those that women would be taking.

Both the moderate and the high doses resulted in a 4.5-fold increase in blood estrogen levels in the mice. This, in turn, was linked with fluid retention in the uterus, protein in the urine and dilated kidneys. These doses also increased atrial natriuretic peptide (ANP), a hormone that is a marker of severity of heart failure.

Low doses of estrogen, on the other hand, put blood estrogen levels back to those seen in control rodents -- those not receiving replacement estrogen. The low-dose mice didn't experience fluid retention, kidney damage or changes in ANP levels.

Sethi said it makes sense that different dosages may result in different outcomes. "That's why I think it's very important when women talk to their doctors that they ask, 'Is the time right?' And I think the amount of medication you take should be kept to a minimum."

Previous studies have shown less cardiovascular risk in women under 60 who take HRT.

Doctors now typically recommend that women looking to hormone replacement therapy to counter menopausal symptoms take the lowest possible dose for the shortest amount of time.

More information

Visit the U.S. National Heart, Lung, and Blood Institute for more on hormone therapy and the Women's Health Initiative.