Bone Abstracts

The objective of this investigation was to compare bone mineral density (BMD) attained from dual-energy X-ray DXA with speed of sound (SOS) data attained from a Beam-Med Omnisense multisite quantitative ultrasound (mQUS) in a large sample of randomly-selected community-based individuals from the Canadian Multicentre Osteoporosis Study (CaMOS). A total of 1177 men and 2949 women were assessed with mQUS at the distal radius, tibia, and phalanx sites as part of the Canadian Multicentre Osteoporosis Study (clinical sites included Saskatoon, Calgary, Hamilton, Quebec City, Halifax and St Johns). Estimated stiffness was provided at each site as SOS (m/s). BMD (g/cm²) was assessed at the lumbar spine (L1–4; LS), femoral neck (FN), total hip (TH), and the greater trochanter (GT) by DXA. Pearson product-moment correlations were performed between measures of BMD and SOS for men and women separately. Alpha was set at P<0.05 for all analyses. In this subset of CaMOS data, the mean (S.D.) age for the women was 66.5 (11.49) years and 63.7 (13.04) years for men, with a range of 30–96 years of age. Correlations between BMD and SOS were low (0.02–0.31), irrespective of QUS site or DXA site investigated (all correlations for women were statistically significant, numerous correlations for men were statistically significant). Controlling for height and weight (partial correlation) did little to change the correlations. The greatest r2 attained indicated that there is at best 10% of the variance shared between the measures; most associations were far weaker. While the power of this sample allowed for statistically significant results to be found between the DXA BMD and mQUS it can be safely assumed that they were measuring different attributes of bone. Therefore, these analyses demonstrated that BMD and SOS are relatively independent from one another and therefore may both contribute independent information to fracture risk assessment tools.