What's Appropriate?
In a 2007 position statement that also recommended "FDA-approved commercially available hormonal preparations," AACE added the proviso that these should be prescribed "following the guidelines published by the various medical societies." This is where the discussion of bioidentical hormones enters the grayest area.
"Estradiol and progesterone are used for the management of vasomotor symptoms that are troubling to the patient, and they should be used within usually the first five years of menopause—the lowest dose, for the shortest amount of time," Ribowsky summarizes. "In terms of being a fountain of youth or a way to stay or look younger, there's not really any support for those types of claims. They're not even studied for that purpose."
Neither Egan nor Nunn refers to a "fountain of youth"; their aim is to keep patients healthy and feeling better. (Although, yes, patients often comment that they feel younger, too.) Both emphasize that patients are monitored and HRT is adjusted accordingly. As Nunn says, the goal is physiologically normal levels—literally replacing lost hormones—not bodybuilder levels.
In terms of safety, Nunn in particular defends estrogen. "If you go back to the Women's Health Initiative study, the one that was 'the estrogen sky is falling,'" he says, "the women who were taking only the [conjugated estrogen] product didn't have an increased risk for breast cancer—only the women who were on the [estrogen plus progestin]. So you really can't blame the estrogen here."
Egan says she doesn't prescribe oral estrogen products because "it's too hard on the liver. The liver methylates it to estrone, which can increase risk for breast cancer."
In terms of cardiovascular risk, Nunn also prefers nonoral routes of administration for estrogen. "If you absorb your estrogen, it doesn't increase your clotting factors, because you avoid the first pass through the liver," he says. "So absorbed estrogen—patches, creams, pellets—doesn't increase your risk for stroke and heart attack."
Even so, patients are encouraged to have regular health screenings, as appropriate. "We certainly have our patients continue to get bone mineral density scans, keep current on their mammograms and Pap smears, and follow all the other things you should do for good health maintenance," Nunn says.
One point on which everyone agrees is the need for additional research to establish what benefits bioidentical HRT offers. The Cochrane Collaboration is expected to publish a review later this year that examines the evidence on bioidentical hormones for vasomotor symptoms; that may shed some light on their safety and efficacy. But Ribowsky, for one, would like to see some head-to-head randomized controlled trials comparing bioidentical HRT with conventional HRT.
"I think when we have studies like that available, we can make recommendations to our patients more clearly and more confidently," she says.
Egan notes that everything she learned in her fellowship was based on available evidence, but wonders if additional research would alter the view of organizations such as ACOG. "I'm just sad to say that the FDA and ACOG are about 20 years behind the times," she says, adding that insurance companies also send her letters requesting that she use conjugated estrogen preparations instead of (FDA-approved) bioidenticals.
"I'm not going to do anything to harm my patients, and we know those drugs cause breast cancer," she adds. "Why would I use those? I think the biggest thing is that we have to identify the difference between synthetic chemicals and the bioidentical hormones in the right form."