Prediction of Vertebral Fractures Is Specific for Gender and Site of Bone Mineral Density Measurement

Objective. To investigate basic assumptions of prediction models for future vertebral fractures. Methods. Lateral radiographs of the spine were obtained from 314 Portuguese individuals aged 60 years or older (205 women and 109 men) with bone mineral density (BMD) measurements at several sites. Associations between BMD at various sites, participant characteristics, and vertebral fractures were investigated. For men and women separately, logistic regression analyses and analyses of areas under the receiver-operating characteristic (ROC) curves were performed to determine the accuracy of BMD measurement at predicting the presence of vertebral deformities. Results. BMD measurements at all sites significantly predicted the presence of osteoporotic vertebral deformities in women but not in men. Similarly, in analyses of areas under ROC curves, BMD assessments were statistically significantly related to vertebral deformities in women but not in men. In multivariate analyses, BMD measurements of the lumbar spine and of the forearm, adjusted for gender, age, and body mass index, significantly predicted the presence of vertebral deformity, but BMD of the hip sites did not. Conclusion. Prediction of fractures is specific for gender and site of BMD measurement. This challenges the use of similar algorithms for men and worsen as well as the use of hip BMD data to accurately estimate future vertebral fracture risk. (First Release Nov 15 2009; J Rheumatol 2010;37:149-54; doi:10.3899/jrheum.090731)