Find out if you’re losing bone mass and need to reverse the loss. An astounding number of people, today, suffer from the bone-weakening disease osteoporosis. Many of them aren’t even aware of it. Women lose bone mass at menopause — often very quickly—when their bodies begin to produce fewer estrogens. If osteoporosis is found early, its damaging effects can be reduced with diet, exercise, and possibly oestrogen replacement therapy or other bone-building medications. Tests to determine bone density are safe and painless and can be a useful tool if you’re trying to decide if hormone replacement therapy (HRT) is right for you.
The following people should have a BMD test:
Women 65 and older, regardless of other osteoporosis risk factors.
All postmenopausal women who have a fracture.
Postmenopausal women who have one or more of the following risk factors:
Personal history of fracture as an adult
History of fracture in a first-degree relative
Caucasian race
Advanced age
Dementia
Frail or in poor health
Smoke cigarettes
Low body weight
Estrogens deficiency
Lifelong low calcium intake
Alcoholism
Impaired eyesight despite adequate correction
Recurrent falls
Inadequate physical activity
While not covered by the guidelines, premenopausal women with multiple risk factors (listed below) may be at increased risk for developing osteoporosis and may want to get a BMD test as well:
Thin frame
Family history of osteoporosis
Low-calcium diet
Drinking alcohol
Smoking cigarettes
Not getting much exercise
Having taken steroid-based medications,
Anticonvulsants, or thyroid hormone for a long period of time
The test involves a scanner that uses a small amount of radiation to measure bone density. (Standard X-rays are not sensitive enough to detect osteoporosis until the disease is fairly advanced.) The most common tests send multiple wavelengths of radiation through a bone, and then measure the fraction of energy that passes through. The denser the bone, the less radiation will pass through. Bone density can be measured at the spine, hip, wrist, or heel. Your doctor will determine the best test for you. Very low bone mass at any place in the body is a good indicator that osteoporosis affects the entire body.
A device that uses high-frequency sound waves to measure bone density is also used for the test. A person puts her foot into a small box, where the sound waves painlessly penetrate the heel bone for ten seconds. Measuring the heel bone can predict osteoporosis as well as measuring the hips or spine. The device is intended for identifying patients at risk for fractures.
Your bone health is figured using two numbers—your Z score (a number that compares you with an average woman of your same age and body size) and your T score, which compares your bones to those of a hypothetical young person with optimum bone strength. A low score in either area shows that bone was lost, or not enough was formed, at some point in your life. In order to see if you are continuing to lose bone mass, you’ll need to repeat the test over time. If your Z score is considerably lower than the average, it’s probably due to a coexisting disease (such as Type 1 diabetes, mal-absorption problems, or a calcium deficiency) or to a medication (such as excessive thyroid medication).
Further tests will be needed to determine the cause of a low score. Having two or more tests over a two to five year period can help determine how quickly you are losing bone mass.
