Women with normal bone density are unlikely to develop osteoporosis within 15 years and can forego the duel-energy X-ray absorptiometry (DXA) radiology exams to detect it for at least that long, researchers reported online January 19 in the New England Journal of Medicine.
A team led by Margaret Gourlay, MD, MPH, of the University of North Carolina at Chapel Hill, tracked 4,957 women ages 67 and older for 15 years. The women had normal bone mineral density (BMD) or osteopenia (low BMD) and no history of hip or vertebra fracture, or treatment for osteoporosis. The aim was to provide a foundation for decisions about the interval between BMD tests.
The team defined an ideal BMD testing interval as the estimated time for 10 percent of women to make the transition to osteoporosis, but not yet break a hip or crack vertebrae.
Over the course of the study, 0.8 percent of women with normal BMD developed osteoporosis; among those with those with mild, moderate, and advanced osteopenia, 4.6 percent, 20.9 percent, and 62.3 percent developed it, respectively.
For women with normal BMD, the team established estimated testing intervals 16.8 years for women with normal BMD and 17.3 years for women with mild osteopenia. Women with moderate and advanced osteopenia would need more frequent testing, the team says — at 4.7 years and 1.1 years.