Degraded microarchitecture by low trabecular bone score is associated with prevalent vertebral fractures in patients with systemic lupus erythematosus

Purpose: Recently, trabecular bone score (TBS) has emerged as an important supplementary assessment tool in osteoporosis diagnosis and management. The high incidence of fragility fracture within the non-osteoporotic range of bone mineral density (BMD), among systemic lupus erythematosus (SLE) patients, highlights the crucial role of bone microarchitecture in osteoporosis. This study aimed to evaluate whether TBS identified existing vertebral fractures (VF) more accurately than BMD in SLE patients. Methods: This study enrolled 147 SLE patients from the Asia Pacific Lupus Collaboration (APLC) cohort, who had BMD and TBS assessed from January 2018 until December 2018. Twenty-eight patients sustaining VF and risk factors associated with increased fracture occurrence were evaluated. Independent risk factors and diagnostic accuracy of VF were analyzed by logistic regression and ROC curve, respectively. Result: The prevalence of vertebral fracture among SLE patients was 19%. BMD, T-score, TBS, and TBS T-score were significantly lower in the vertebral fracture group. TBS exhibited higher positive predictive value and negative predictive value than L spine and left femur BMD for vertebral fractures. Moreover, TBS had a higher diagnostic accuracy than densitometric measurements (area under curve, 0.811 vs. 0.737 and 0.605). Conclusion: Degraded microarchitecture by TBS was associated with prevalent vertebral fractures in SLE patients. Our result suggests that TBS can be a complementary tool for assessing vertebral fracture prevalence in this population.