Fracture prediction models are sex- and site-specific

Prediction of fractures is specific for the patient’s sex and the site of bone mineral density (BMD) measurement. This finding challenges the practice of using similar models-and of measuring BMD at the hip only-to predict fracture risk for men and for women.

Jacobs and colleagues investigated the association between vertebral fractures and patient age, sex, and BMD at several sites in 314 women and men 60 years and older. Dual-energy x-ray absorptiometry scans of the spine and proximal femur were obtained.

BMD measurements at all sites accurately predicted osteoporotic vertebral fractures in women but not in men. Correlation coefficients of BMD at the lumbar spine with BMD at the hip were higher in men than in women; coefficient correlations between BMD at the total forearm and other sites were higher in women. BMD measurements of the lumbar spine and forearm, adjusted for age, sex, and body mass index, significantly predicted the presence of vertebral deformity, but BMD of the hip sites did not.

The authors noted that the fracture risk assessment tool (FRAX) uses only BMD at the femoral neck and, therefore, FRAX would predict hip fractures more reliably than all “major osteoporotic” fractures.