The diagnosis of osteoporosis was once made on the basis of the "washed out" appearance of the bone on an X-ray or via an actual bone biopsy. In the late 1980s, the advent of dual-energy X-ray absorptiometry (DEXA) paved the way for a class of drugs called bisphosphonates (such as Actonel, Boniva, and Fosamax). Those drugs were approved not only to treat osteoporosis but also to prevent it. Direct-to-consumer ads proliferated, urging patients to be tested and treated. Some makers of popular bone drugs subsidized the rental of DEXA (or DXA) units for practitioners' offices.
But DEXA results were not the only way to determine a fracture risk. Beyond the usual predictors of age (older than 65), gender (female), race (Asian or Caucasian), low weight, and previous fracture, there were current smoking habits, previous use of corticosteroids, family history of fracture, excessive alcohol use, and rheumatoid arthritis. Additional risk factors included vitamin D deficiency, thyroid or parathyroid hyperfunction, and celiac disease. Factor in causes of repeated falls, such as poor balance and muscle weakness, and you can see that DEXA measurements can often be just one of myriad predictors.
Such was the case with one of my patients, a math teacher. Except for a T-score of -2.6 based on a rating system designed by the World Health Organization, she had no risk factors for future fractures. Using a computer tool called FRAX (www.sheffield.ac.uk/frax), developed by WHO, I was quickly able to determine her 10-year fracture probability. Despite her ominous T-score, according to the FRAX calculation, the likelihood of her having a fracture was only 2.9 percent over the next decade.
Considering her aversion to taking medication and noting studies that determined that cost-effective treatment to prevent future fractures was warranted when the probability was 3 percent or greater, I decided that medication wasn't necessary now. I made sure that her daily calcium and vitamin D intake were adequate, stressed the importance of weight-bearing exercise, and asked her to return in one year for another bone-density test.