Prevalence and risk factors of vertebral fracture in female Japanese patients with systemic lupus erythematosus

Objective: We examined the prevalence and risk factors of vertebral fracture in female Japanese patients with systemic lupus erythematosus (SLE). Methods: We performed lateral radiographs of the thoracic and lumbar spine and bone mineral density (BMD) measurements and collected demographic, lifestyle, clinical, and treatment characteristics of 52 SLE patients. Vertebral fractures were defined as a >20 % reduction of vertebral body height. Odds ratios (ORs) and their 95 % confidence intervals (CIs) were computed to assess the strength of associations between vertebral fractures and selected factors among SLE patients. Results: At least one vertebral fracture was detected in 50 % of SLE patients. A history of previous bone fracture was significantly associated with an increased risk of vertebral fractures among SLE patients (adjusted OR = 14.8, 95 % CI = 1.62-134; P = 0.017). Daily use of tea or coffee was marginally associated with a decreased risk of vertebral fractures among SLE patients (adjusted OR = 0.11, 95 % CI = 0.01-1.01; P = 0.051). Conclusion: The high prevalence of vertebral fracture in SLE patients (50 %) indicates that we need to assess the lateral spine radiograph in more female Japanese SLE patients regardless of BMD and use of corticosteroids, although additional studies are warranted to confirm the findings suggested in this study.