HRT: risky or beneficial?

What does all the recent hoopla over hormone replacement therapy (HRT) mean for 50-plus women? Dr. Mary C. Tierney, director of geriatric research at Sunnybrook and Women’s College Health Sciences Centre, thinks headlines following the sudden shutting down of an American clinical trial this summer have women spooked. She’s worried they’ll be afraid to use HRT even though it has proven health benefits.

Benefits as well as risk
Indeed, the terminated study did confirm the positive role of hormones in reducing the risk of colon cancer and bone fracture. And the Women’s Health Initiative (WHI) scientists who conducted the trial noted the value of HRT in providing relief for the 20 to 25 per cent of menopausal women who suffer severe symptoms such as hot flashes and sleep-depriving night sweats.

They did, however, urge physicians to warn patients of the increased risk of cardiovascular events, strokes and blood clots even for short-term use, and invasive breast cancer if used for longer than four years.

“Women who are taking HRT need to have regular mammograms and be vigilant,” advises Tierney.

The prematurely ended trial byhe WHI had been tracking 16,608 women with an intact uterus who were taking daily either an inactive placebo or Prempro, a pill that combined Premarin (estrogen) and Provera (progestin). (Giving both hormones reduces the risk of endometrial cancer in women with a uterus.)

Other ongoing WHI studies continue to investigate the protective value of low-fat diets, calcium and vitamin D supplementation and hormone replacement therapy specifically for women who have had hysterectomies. These latter women are receiving a placebo or estrogen alone.

“In the part of the study where they’re not using Provera, they found no increased risk of heart disease. So what is that telling you?” Tierney asks. “Maybe it’s Provera… This one particular combination may be the problem.”

Next page: Women advised to make lifestyle changes

Women advised to make lifestyle changes
The Society of Obstetricians and Gynecologists of Canada points out that, theoretically at least, other formulations might act differently but cautions that before they could be confidently recommended, similar large-scale studies would have to be carried out. The American College of Obstetricians and Gynecologists (ACOG) advises women to make appropriate lifestyle changes and not to take HRT for protection against heart disease.

  • Adverse heart events affected seven more women per 10,000 on HRT than those who were taking a placebo
  • Eight more per 10,000 women on HRT were diagnosed with breast cancer than were women taking a placebo.

This small ratio drawn from a very large pool of women taking HRT over many years would ultimately balloon into a large number of harmed women, yet a small ratio would translate into a small risk to an individual. ACOG noted the risk of breast cancer for one person would be less than one tenth of one per cent a year. (In this case, the risk was additive: the longer a woman took HRT, the greater the risk of breast cancer.)

Misconceptions may affect research
“The unfortunate thing is that everybody is jumping to the conclusion that HRT is bad,” Tierney says, “that we shouldn’t use it. That may not be justified at all.” And, she adds, “I’m concerned that important studies looking into the beneficial effects will grind to a halt. Misconceptions about the results of this study may put a damper on research into the positive health outcomes of other estrogen-progestin combinations.”

Tierney heads up the Estrogen Memory Study, a two-year placebo-controlled clinical trial testing the effect of HRT on memory loss and as a therapy for Alzheimer’s disease. Estrogen plays a role in temperature regulation, hence the night sweats that disrupt sleep and lead to tiredness and loss of concentration. “But studies have shown very subtle changes in memory and other cognitive functions after menopause that can’t be blamed on poor sleep.”

Tierney has had to reassure the women in her study that they are being carefully monitored and that the estrogens and progestins they may be receiving are not the same as the ones used in the WHI. “They’re on edge,” she says. “It’s too bad, because if this is something that can delay the onset of Alzheimer’s disease by five years, most women would take it – I certainly would.”

Dr. Michael Thomas, an investigator in the WHI clinical trials and the director of the division of reproductive endocrinology and infertility at the University of Cincinnati College of Medicine thinks HRT has its place. He observes the study didn’t look at the sequential use of HRT (estrogen daily, plus 10 to 12 days of progestin a month), which, he says, “is probably how the majority of people taking an estrogen-progestin combination use it.”

Women are missing out on benefits
But Thomas points out, “80 per cent of [menopausal] women don’t take HRT and 50 per cent who do get a prescription don’t fill it.” He’s concerned they are missing out on the known benefits of HRT, especially its protective effect on bone.

“People who are of European descent are at risk for osteoporosis,” he says, adding that people who drink a lot of caffeine, smoke, take thyroid replacement therapy, have sedentary jobs or who don’t get much sunlight risk bone loss.

Thomas, Tierney and the writers from the Women’s Health Initiative all advise women to discuss their particular need for HRT with their own physicians. But if the decision is to not take the hormones, Thomas suggests a backup plan for your bones. “Take up to 1,500 mg of calcium a day if you’re not on HRT,” he says. Follow a diet rich in calcium diet, and don’t forget the importance of weight-bearing exercises.

“Bones are like a bank,” he says. “If you don’t contribute to that bank every day, you’re going to start to have a decline in the calcium content of your bones.”