Prevalence And Risk Factors Of Osteoporosis In Ankylosing Spondylitis Patients With Hip Joint Involvement

OBJECTIVE:The aim of this study was to investigate the prevalence and risk factors for reduced bone mineral density(BMD)in patients with ankylosing spondylitis(AS).METHODS:Eighty-two AS patients with hip joint involvement and eighty healthy controls were enrolled.The clinical data of AS patients were collected.The data included thoracic and lumbar X-rays,C-reactive protein(CRP)levels,and the erythrocyte sedimentation rate(ESR),HLA-B27,Bath Ankylosing Spondylitis Disease Activity Index(BASDAI),Bath Ankylosing Spondylitis Functional Index(BASFI),Bath Ankylosing Spondylitis Metrology Index(BASMI),and so on.BMD of the lumbar vertebrae(L1-4)and the left proximal femur(the femoral neck)was measured using dual-energy X-ray absorptiometry(DEXA).RESULTS:78.05% osteoporosis or osteopenia was diagnosed in ankylosing spondylitis patients with hip involvement and it was significantly higher than that in the normal control group(32.5%).Compared with the normal controls,AS patients showed a higher osteopenia(46.3% VS.27.5%)and osteoporosis(31.7% VS.5%)incidence.However,the rate of bone mineral density measurement and anti-osteoporosis treatment in patients with AS were extremely low.The BMD levels of lumbar and femoral neck in AS patients with hip involvement were significantly lower than that in the normal control group.Correlation analysis showed that bone loss in the lumbar spine was associated with higher ESR levels and Low hip BMD was associated with the height,weight,BASDAI and CRP levels.CONCLUSIONS:BMD in the lumbar and femoral neck of AS patients with hip involvement was significantly decreased.The increased ESR and CRP levels,high disease activity were the risk factors for bone loss in AS patients.The prevalence rate of osteoporosis in AS patients was very high,but he rate of BMD measurement and anti-osteoporosis treatment were extremely low.