Protecting your bones after menopause

by Mary Calvagna

Menopause occurs when a woman's menstrual cycle stops permanently. The process includes a decline in ovarian hormones, particularly estrogen, and is a natural, biological event that happens to all women.

Numerous studies over the past 10 years have linked low levels of estrogen to osteoporosis, the condition in which the bones become fragile and fracture easily. In fact, research has shown that osteoporosis is more closely related to menopause than to a woman's chronological age.

Replacing hormones lost in menopause

To alleviate the symptoms associated with this decline in estrogen and other hormones, doctors prescribe hormone replacement therapy (HRT). HRT is used to ease the hot flashes and vaginal dryness that accompany menopause. In addition, the estrogen in HRT has been shown to provide protection against osteoporosis and, for some women, cardiovascular disease.

Taking estrogen, however, is not without side effects or risk. Some women experience bloating, breast tenderness, cramping, irritability, and depression. HRT may also increase risk for breast cancer, blood clots, and endometrial cancer.

Given the risks and the benefits of taking estrogen, the decision of whether or not to use HRT is difficult. However, a new class of drugs called "selective estrogen-replacement modulators" (SERMs) may make this decision easier. These drugs are believed to mimic estrogen's effects in some parts of the body, but not in others.

Raloxifene: working to protect your bones

A SERM called raloxifene (Evista) has been shown to positively affect bone and lipid metabolism similarly to estrogen, while simultaneously inhibiting the negative effects of estrogen in the uterus and the breast. These effects are detailed in a study published in the Archives of Internal Medicine* that looked at raloxifene and its effect on post-menopausal women.

Researchers analyzed data on 1145 healthy, postmenopausal women, ages 45 through 60. The women were randomly assigned into one of four groups: a raloxifene dose of 30 mg/day, a dose of 60 mg/day, a dose of 150 mg/day, or a placebo. Throughout the study, bone mineral density of the spine, hip, and total body was measured, and blood samples were drawn and analyzed.

During three years of treatment, the groups receiving raloxifene reduced bone turnover and preserved bone mineral density more than the group taking the placebo. Raloxifene therapy also reduced serum LDL-cholesterol levels (on average, almost 9 mg/dL). The only adverse event experienced by more people in the raloxifene-treated groups was hot flashes.

In light of their results, the authors of this study recommend a 60 mg/day dose of raloxifene for the prevention of postmenopausal bone loss.

Steps to help prevent osteoporosis

For long-term osteoporosis prevention, the National Osteoporosis Foundation outlines four key steps:

  • Eat a balanced diet rich in calcium and vitamin D
  • Do weight-bearing exercise, such as walking, dancing, weight-lifting, or stair climbing
  • Adopt a healthful lifestyle, avoid smoking or excessive alcohol use
  • Get bone density testing done regularly and take medications when appropriate

These lifestyle factors are essential for all women. However, each woman's profile is different, so be sure to talk to your doctor about which medication is best for you.

Resources

* "Long-term effects of Raloxifene on bone mineral density, bone turnover, and serum lipid levels in early postmenopausal women," by CC Johnston Jr., et al. Archives of Internal Medicine, December 11/25, 2000, Volume 160, pp. 3444-3450.