Sarah D. Berry, M.D., M.P.H., of the Institute for Aging Research, Hebrew SeniorLife, Boston, and colleagues conducted a study to determine whether changes in BMD after 4 years provide additional information on fracture risk beyond baseline BMD. The population-based cohort study involved 310 men and 492 women from the Framingham Osteoporosis Study with 2 measures of femoral neck BMD taken four years apart between 1987-1999. The primary measured outcome was risk of hip or other major osteoporotic fracture through 2009 or 12 years following the second BMD measure. Average age was 75 years.
After a median (midpoint) follow-up of 9.6 years, the average BMD change was -0.6 percent per year. During follow-up, 113 participants (14.1 percent) experienced 1 or more major osteoporotic fractures (88 hip, 24 spine, 5 shoulder, and 33 forearm fractures). The net change in the percentage of participants with a hip fracture correctly reclassified with a second BMD measure was 3.9 percent; the net change in the percentage of participants without hip fracture correctly reclassified by a second BMD measure was -2.2 percent. The researchers found that the net change in the percentage of participants with a major osteoporotic fracture correctly reclassified with a second BMD measure was 9.7 percent; the net change in percentage of participants without major osteoporotic fracture correctly reclassified by a second BMD measure was -4.6 percent.
The authors conclude that for older patients not undergoing treatment for osteoporosis, "... BMD change provided little additional information beyond baseline BMD for the clinical management of osteoporosis." The second BMD measure reclassified a small proportion of individuals, and it is unclear whether this reclassification justifies the current U.S. practice of performing serial BMD tests at 2.2-year intervals. "Further study is needed to determine an appropriate rescreening interval and to identify individuals who might benefit from more frequent rescreening intervals."
Source: Eurekalert
