Elderly Women with Normal Bone Mineral Density or Mild Osteopenia Appear to Have Low Risk of Progression to Osteoporosis or Hip Fracture Over 15 Years
DynaMed Weekly Update - Volume 7, Issue 4
Bone density testing is recommended in healthy women ≥ 65 years old to screen for osteoporosis (National Osteoporosis Foundation 2010 PDF, Ann Intern Med 2011 Mar 1;154(5):356), but data to determine the optimal interval between screens have been lacking. A recent cohort study followed 4,957 women with normal bone mineral density (BMD) or osteopenia by dual-energy x-ray absorptiometry for up to 15 years. All women were ≥ 67 years old at baseline. Women with a history of hip or clinical vertebral fracture or osteoporosis were excluded.
Women were stratified by baseline BMD for analysis. Osteoporosis developed in 0.8% of women with normal BMD, in 4.6% with mild osteopenia, in 20.9% with moderate osteopenia, and in 62.3% with advanced osteopenia. Hip fracture or clinical vertebral fracture occurred in 2.4% of the whole cohort prior to diagnosis of osteoporosis by BMD.
Based on these data, the authors estimated the time interval for each group over which osteoporosis would develop in 10% of the women before they suffered a hip fracture or clinical vertebral fracture. The intervals were 16-18 years for women with normal BMD or mild osteopenia, about 5 years for moderate osteopenia, and 1 year for advanced osteopenia. They also assessed the time intervals for 2% of women to have a hip or vertebral fracture before the development of osteoporosis. These times were estimated at > 15 years for normal BMD or mild osteopenia and about 5 years for moderate or advanced osteopenia (level 2 [mid-level] evidence) (N Engl J Med 2012 Jan 19;366(3):225). While this study cannot determine the optimal interval between screening BMD tests, it may help inform the discussion between clinicians and patients.
For more information, see the Osteoporosis topic in DynaMed.