Osteopenia

Osteopenia is not a disease. It is a condition marked by a decrease in optimum bone density that can be a precursor to osteoporosis, where bones become brittle and subject to fractures.

Data from the Canadian Multicentre Osteoporosis Study (camos.org) show that osteopenia affects 46 percent of women and 39 percent of men aged 50 and over. Dr. Jerilynn Prior, professor of medicine and endocrinology at the University of British Columbia, explains that osteopenia is a laboratory finding based on results from a bone mineral density (BMD) test.

Testing for Bone Mineral Density

The BMD test, which is offered by many hospital laboratories and x-ray clinics, is painless and noninvasive. Results are reported as the number of standard deviations below the average values of a healthy 20- to 30-year-old woman. A bone density within the range of 1 to 2.5 standard deviations below average is defined as osteopenia, and greater than 2.5 standard deviations below average is diagnosed as osteoporosis.

Readings are taken from the lower spine and hip. If one has low bone density, it is recommended that a BMD test be repeated every two years and, if possible, on the same machine in order to monitor the condition. Dr. Prior thinks that the test is reasonably accurate and useful in the assessment of bone mass, although it does not address bone strength. Because many people over the age of 50 have arthritis of the spine, the spinal measurement is not as reliable as the hip reading.

To Treat or Not to Treat

Dr. Prior has many patients who have gained bone mass without adopting drug therapy. She says it’s a “whole meal deal” that includes following all of the ABCs of bone health, and also getting a deoxypyridinoline (or D-pyr) urine test, which indicates the rate of bone resorption. If the D-pyr result is normal, drug therapy is unnecessary. However, if a woman in perimenopause has osteopenia, treatment may be needed, as bone loss is rapid from the time of irregular cycles up to four years after the final period.

Dr. Prior feels that many menopausal women with osteopenia who have never had a bone fracture will never develop osteoporosis. “What really matters are fractures. Every fracture that occurs with a force no more than a fall from standing height indicates osteoporosis. I take a fragility or low-trauma fracture very seriously, even if the BMD is normal.”

PDF Table of ABCs of Bone Health for Women in Midlife