Performance of HR-pQCT, DXA, and FRAX in the discrimination of asymptomatic vertebral fracture in postmenopausal Chinese women

SUMMARY: Volumetric bone density (vBMD) and trabecular microarchitecture measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) can discriminate the patients with high risk of asymptomatic vertebral fracture (VF) in postmenopausal Chinese women. These findings suggested that HR-pQCT could provide additional information on bone quality of the patients with asymptomatic VF. INTRODUCTION: Although there were several studies using HR-pQCT to investigate asymptomatic VF, it remains uncertain if HR-pQCT parameters can discriminate asymptomatic VF patients, especially in Chinese population. The purpose of this study was to investigate whether bone quality measured by HR-pQCT could discriminate asymptomatic VF independent of hip areal bone mineral density (aBMD) measured by dual-energy x-ray absorptiometry (DXA) and fracture risks evaluated using built-in Fracture Risk Assessment Tool (FRAX(BMD)). METHODS: This is a nested case–control study. One hundred seventy-five ambulatory Chinese postmenopausal women aged 60–79 years were retrieved from Normative Reference Standards (NRS) cohort in Hong Kong. DXA was used to identify VF from lateral spine images (VFA) using Genant’s semi-quantitative method. Major osteoporotic fracture risk was calculated using FRAX tool. HR-pQCT was used to assess vBMD, microarchitecture, and estimated strength at both distal radius and tibia. Comparison of HR-pQCT parameters between asymptomatic VF and control was performed using covariance analysis. Logistic regression analysis was performed for calculating the adjusted odds ratio (OR) with 95% confidence intervals (CI) of fracture status as per SD decrease in HR-pQCT parameters. RESULTS: Women with asymptomatic VF were older than those of the control in our NRS cohort. Nevertheless, after adjusted for covariance, asymptomatic VF showed significantly lower trabecular vBMD (Tb.vBMD) at radius but higher SMI at tibia as compared with those of the control. Tb.vBMD at radius yielded the highest value of area under the curve (AUC) as compared with total hip aBMD and FRAX(BMD). However, no significant difference was found among each other. CONCLUSION: Tb.vBMD at the radius and SMI at the tibia provided by HR-pQCT can discriminate asymptomatic VF independent of hip aBMD and FRAX(BMD) by DXA in postmenopausal women.