At menopause, when estrogen levels fall, women suddenly experience a rapid loss of bone and an increased risk of fractures. Hormone replacement therapy involves taking estrogen to treat menopausal symptoms, such as hot flashes, night sweats and vaginal dryness.
The most common formulation also contains a synthetic form of progesterone to counteract the increased risk of uterine cancer in women who take estrogen alone. Women who have had a hysterectomy are able to take estrogen without progesterone.
In addition to easing the symptoms of menopause, hormone replacement therapy reduces the rapid loss of bone that accompanies it. The sooner hormone replacement therapy begins after menopause, the greater the preservation of bone.
Risks of hormone replacement therapy
The decision to use hormone replacement therapy should not be taken lightly, however. One of the most common forms, conjugated equine estrogen plus medroxyprogesterone (Prempro), has been found to increase the risk of breast cancer and cardiovascular events (such as heart attacks, strokes and blood clots) when taken for several years.
Thus, hormone replacement therapy should be used at the lowest effective dose for the shortest time needed to treat menopausal symptoms. If a woman is concerned about bone loss and is thinking about hormone replacement therapy, she should discuss her personal risk and benefit profile with her doctor. Keep in mind that hormone replacement therapy is no longer recommended solely for the prevention of osteoporosis; other drugs are available that can accomplish the same goal.
One caution: As soon as a woman stops taking hormone replacement therapy, bone loss will begin again. Consequently, it is important to assess the need for osteoporosis treatment before discontinuing hormone replacement therapy.
Testosterone in men
For men with abnormally low levels of testosterone, which can cause osteoporosis, testosterone replacement therapy to help preserve their bones may be an option.