Diagnosing Osteoporosis

Osteoporosis can severely affect your quality of life.

Sherrie Hertz, BScPhm, is a Drug Information Pharmacist at the Drug and Research Information Centre, Toronto.

As we age, our bones become weaker. Osteoporosis is a disease where the bones are “porous” and more likely to break, unlike the denser, stronger bones of youth. In Canada, one out of every four women, and one in eight men, will develop osteoporosis. Often the first time you are aware that you have the condition is when you experience a broken bone. Osteoporosis can severely affect your quality of life and keep you from doing simple things like walking and climbing stairs. that is why early detection and prevention are so important.

The best way to test the strength of your bones is through bone mineral density (BMD) testing. The dual-energy x-ray absorptiometry (DXA) test is the most accurate way to measure BMD, so it is the preferred method. The DXA test is similar to an x-ray, but uses less radiation. It is painless, easy, and takes only a few minutes. Measurements are taken at the hip, spine, and forearm. Where DXA testing is not available, other methods (e.g., heel ultrasound) may be used for an initial screening, but they are not as reliable.

Results of BMD testing are described as the difference between your BMD compared to the usual results for a young, healthy person of the same gender and race. A number is given, called a “T-score.” A T-score between +2.5 and -1.0 is normal. Results from -1.0 to -2.5 indicate a low BMD, a condition called osteopenia. Osteoporosis is diagnosed with a T-score below -2.5. The lower the T-score, the greater the risk of broken bones (fractures). DXA testing is also used to watch for progress of the disease and the expected benefits of prescribed medications. Additional blood and urine tests may also be used to confirm a diagnosis of osteoporosis.

Because there are no warning signs of osteoporosis, people at high risk of fractures should have their BMD tested. This includes people over the age of 65, and those over the age of 50 with additional risk factors, such as:

  • Family history of osteoporosis
  • Early menopause
  • Previous fracture due to weak bones after the age of 40
  • Long-term corticosteroid medication use.

Rheumatoid arthritis, poor nutrition, smoking, excessive alcohol and caffeine intake, and the use of anticonvulsant medications are also risk factors.

By knowing your BMD, you can take action to prevent fractures, and their serious consequences, as soon as possible. Osteoporosis prevention includes weight-bearing exercise (such as walking), stopping smoking, good nutrition (with enough calcium and vitamin D), and limited alcohol and caffeine intake.

For more information, visit The Osteoporosis Society of Canada at www.osteoporosis.ca or The Arthritis Society at www.arthritis.ca.