Department of Health and Human Services
FDA - Office of Women's Health

What is Osteoporosis?

From birth onward, your bones are constantly renewing themselves. Slowly but steadily, old bone is removed and new bone is formed.

With advancing age, particularly after menopause, old bone continues to be removed, but new bone formation starts to lag behind. This results in a gradual and steady decrease in the amount of bone material. This decrease may lead to the condition called osteoporosis, or "porous bones. " As bone density decreases, the bones become weaker and more likely to break (fracture).

Both men and women experience progressive decrease in bone density as they age, however, it will occur more quickly and more severely in some people than others.

Who Will Get Osteoporosis?

The risk of osteoporosis is greater in:

• Women after menopause
  
• Caucasian and Asian women, though African American women are also at risk
  
• Women with a family history of osteoporosis
  
• Women with small bone frames, thin women
  
• Women and men with certain uncommon medical conditions (such as hyperparathyroidism) or use of certain medications such as cortisone, heparin, seizure medicines, and some cancer treatments.

How Can I Tell if I Have Osteoporosis?

There are tests that can measure bone strength and the risk of fracture. One test measures your Bone Mineral Density (BMD). Another test measures other structural features of bone. You should discuss with your doctor whether these tests would be helpful for you.

Description of Testing for Bone strength

There are two main types of tests measuring bone strength:

Radiography
DEXA (Dual Energy X-ray Absorptiometry)

• Uses radiation to determine bone density.
• The spine and hip are most commonly measured, but the heel, wrist or total body may also be measured.
• The procedure takes up to twenty minutes, and results in about as much radiation exposure as a standard X-ray (if the spine or hip is measured) or less (if the heel or wrist is measured).

Sound Waves
Ultrasound

• Uses sound waves to measure bone structure, so there is no radiation exposure.
  
• Measurements are made in the heel or in the shin.
• The procedure can be completed quickly, generally in less than ten minutes.

The results of these tests will vary, depending on the machine used and what part of the body studied. Therefore, if your doctor recommends a follow-up test in the future, make sure that the same type of machine is used to test the same part of your body, so that results may be compared accurately and any changes in your bone noted.

Test Results

Bone measurement test results are reported as a "T score," indicating how far the measurement is below that of a normal person age 20-29:

• Your bone strength is normal if you have a T -score above -1.
  
• You have osteoporosis if you have a score below -2.5.

In general, your risk of a fracture doubles for every point below zero. For example, if you have a score of -2.0, you have twice the risk of fracture of someone with a score of -1.0.

The results of a bone measurement test are site-specific and tell you something about the part of the bone which is measured. But, since bone loss occurs over the entire body, the results at any one site also tell you something about the condition of your bones overall.

Strategies For Bone Health

Regardless of the results of a bone measurement test, all individuals should consider the following measures:

Diet
increase calcium intake from an early age to increase maximum bone density. Foods that are rich in calcium are dairy products, dark green leafy vegetables, tofu and almonds. Dietary supplements are also helpful, and may be necessary for some people to assure adequate intake. The National Academy of Sciences recommends that an "Adequate Intake" of calcium is 1,000 mg/day for individuals under age 50, and 1,200 mg/day in those over 50 years. Vitamin D is also important for calcium absorption and bone health. The recommended daily amount is 400 - 800 IU.

Exercise
particularly weight bearing activities such as walking and jogging.

Life style
stop smoking, limit alcohol use.

Medication

Women with decreased estrogen levels, as a result of either surgical or natural menopause, should, in consultation with their physician, discuss the risks and benefits associated with other medical therapies in addition to the steps recommended above. The risks/benefits of each of these therapies are not easily delineated and depend on an individual's current condition and medical history.

Questions and Answers About Osteoporosis

Should everyone have bone measurement testing?

No, these are not screening tests. You should discuss your risk factors, such as age, medications, medical history and family history with your physician. Together, you can decide on the usefulness of this test for you.

I had bone testing done and the results were normal. Am I safe?

No. The ability of bone strength testing to predict fractures is limited. The fact that one site has a normal result does not guarantee that bone density is normal in other sites. Also, loss of bone density continues with age. Therefore, steps to decrease the loss of bone strength are important regardless of the results of this test.

The testing that I had done showed that I have osteoporosis, and now my family thinks that I will break a bone if I do anything active. Is this fear real?

No. Osteoporosis is an important indicator of the risk of fracture, but it is only one factor. Lifestyle and environmental factors are also important. A diagnosis of osteoporosis should indicate the need to take steps to minimize the risk of a fracture. For example, check the home health hazards such as electric cords or loose rugs; eliminating these risks will help minimize the chance of a fall. Additionally, you should increase your calcium intake and discuss with your physician an appropriate exercise program and the use of medication to improve your bone density.

How often should I have bone measurement testing?

Repeating the test at intervals of less than two years usually will not lead to useful results.

Questions for your doctor

What are my risk factors for osteoporosis?

Should I be taking hormone replacement therapy (HRT) regardless of the bone measurement test result? If so, what are my risk factors for other problems such as heart disease?

What would you recommend if the test shows:

Normal value (-1.0)
Osteonenia (low bone mass -1.0 to -2.5)
Osteoporosis (-2.5 or below)

Sources of Additional Information

FDA Office of Women's Health
5600 Fishers Lane, HF-8
Rockville, MD 20857
http://www.fda.gov/womens

U.S. Public Health Service Office on Women's Health
(800) 994-WOMAN
http://www.4woman.org

American College of Obstetricians and Gynecologists
409 12th Street, S.W.
P.O. Box 96920
Washington, D.C. 96920
http://www.acog.org/

American College of Radiology
(800)532-9934
http://www.acr.org/s_acr/index.asp

National Osteoporosis Foundation
1150 17th Street, N.W
Suite 500
Washington, D.C. 20036-4603
(202) 223-2226
http://www.nof.org/

Osteoporosis and Related Bone Diseases National Resource Center
1150 17th Street, N.W, Suite 500
Washington, D.C. 20036
(202) 223-0344
http://www.niams.nih.gov/Health_Info/Bone/

Older Women's League - OWL
666 Eleventh Street, N.W Suite 700
Washington, D.C. 20001
(202) 783-6686