Pointing the bone at osteoporosis

Box 2 | Hormone replacement therapy

Hormone replacement therapy involves administering an oestrogen supplement to women as their natural supply from the ovaries diminishes during and after menopause. It may also be offered to pre-menopausal women suffering from oestrogen deficiency due to surgical removal of the ovaries, excessive exercise, anorexia or diseases such as Turner syndrome.

Hormone replacement therapy has been shown to protect against post-menopausal bone loss. There is also evidence that its use is associated with reduced fracture rates throughout the skeleton.

In addition, some scientists believe that hormone replacement therapy may have a protective effect against heart disease and stroke. It can also reduce menopause-related symptoms such as hot flushes, mood swings and insomnia.

Are there risks?

When taken alone, oestrogen is believed to increase the risk of cancer to the lining of the uterus. In recent years, oestrogen has been combined with progestogen in hormone replacement therapy to eliminate this risk.

Some studies have suggested that women taking hormone replacement therapy for more than 10 years have a slightly increased risk of breast cancer. Further ongoing research will help clarify the full extent of this risk.

The decision to embark on hormone replacement therapy is often a difficult one. Many medical professionals suggest that women who are undecided about taking the treatment should have their bone density measured. This can be done non-invasively using what is called dual energy x-ray absorptiometry and will give some indication of the risk of developing osteoporosis in the future in the absence of oestrogen replacement.

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Page updated January 2005.