Calcaneous quantitative ultrasound measurements predicts vertebral fractures in idiopathic male osteoporosis.

OBJECTIVES The aim of this study was to identify the differences in ultrasound bone variables (QUS) and to test the ability to discriminate male patients with and without vertebral fractures. METHODS We therefore measured broadband ultrasound attenuation (BUA) and speed of sound (SOS) matched for bone mineral density (BMD) and vertebral deformity in idiopathic male osteoporosis. RESULTS One hundred and seventeen men (age 56.6 range 27-78) were divided into three groups (osteoporosis n=25, osteopenia n=58 and age-matched control n=34) according to BMD T-score by WHO criteria. We found 66 patients (56%) with at least one vertebral deformity during the study. BMD and BUA did not differ, while SOS was lower in osteoporosis (p<0.001) and control group (p<0.001) between the patients with and without vertebral compression. Strong positive correlation was demonstrated between BUA and BMD (lumbar spine r=0.44, p<0.001, femoral neck r=0.56, p<0.001, radius r=0.40, p<0.001), while similar association between SOS and BMD values was not shown. There was no relationship between the BUA and vertebral fracture risk (Odds ratio: 1.14 95% CI: 0.80-1.61). However, the relative risk of vertebral fracture by SOS was 1.56 (95% CI: 1.08-2.62). Adjusting for age and BMI the risk of vertebral fracture did not change (odds ratio for SOS 1.50 95% CI: 1.02-2.22). After adjustment for BMD SOS was still associated with fracture risk at all measured sites (odds ratio: 1.43, 95% CI: 1.02-2.22; 1.41, 95% CI: 1.02-2.17 and 1.32, 95% CI: 1.02-2.0). CONCLUSION Our results suggest that BUA values are more closely related to density and structure while SOS values are able to predict fractures.