The assesment of bone mineral density in patients with early axial spondyloarthritis with Dual Energy X-ray Absorbtiometry(DEXA)

Spondyloarthropathies (SpA) are a group of chronic inflammatory diseases characterized by the inflammation of axial and peripheral joints or tendon and ligament insertions, typical radiological features and extraarticular manifestations. Ankylosing spondylitis (AS), is the major subtype of SpAs. It shows a progressive course with sacroiliac joint and spine involvement. Early axial spondyloarthritis (SpA), is a disease in which the clinical signs of the spondyloarthritis with axial involvement are significant but the radiographic changes of the sacroiliac joint are not present yet. This study was performed with the aim of the evaluation of bone mineral density in patients with early axial SpA by using dual energy x ray absobsiyometry (DEXA) and with the aim of investigation the relationship between bone mineral density and disease activity parameters.Total 75 patients of which 29 patients with mechanic low back pain and 46 patients diagnosed with early axial SpA were included to the study. The study included patients who were between the ages of 18-45. Patient and the control groups filled the BASDAI, BASFİ, VAS, Nottingham health profile, Hospital anxiety and depression scale, short form-36 (SF-36), HAQ-Stanford health assesment questionnaire, HAQ-SpA questionnaire, Ankylosing Spondilitis quality of life scale (AS-QoL), Daugados Functional Index, Daugados Articular Index, Leeds Disability Questionnaire.Complete blood count, routine biochemistry, sedimentation, RF, CRP, HLAB27, Brucella, thyroid function tests, parathyroid hormone, vitamin D, serum ALP, Ca and P levels were measured in the patient and the control groups. 2-way cervical, toracal, lumbar spine radiographs and pelvis AP radiograph were taken both in control and SpA groups. KMY measurements of the control and patient groups were obtained with DEXA method by using Holojic QDR Discovery Wi (S/N 84440) device at the sites of spine (Lumbar 1-4) and hip (femur neck, triangle of femur ward, femur trochanter).When patient and control groups were compared according to L1-L4 BMD and L2-L4 (gr/cm2) score, statistically significant difference has found between the patient and the control groups. L1-L4 BMD and L2-L4 (gr/cm2) values were significantly lower in the patient group than the control group. (p<0.05). Femur total BMD (gr/cm2) and subparameters of the femur neck, wards and troch BMD (gr/cm2) scores were lower in the patient group than the control group, this difference did not reach statistical significance. (p>0.05).As a result, in our study lumbar region BMD was significantly lower in patients with early SpA than controls. There wasn?t any difference in the hip (femur total, neck, troch, wards). These results suggest us to be careful about osteoporosis in patients with early SpA and not to be late to measure BMD in these patients.Key words: Early axial SpA, bone mineral density, dual energy X-Ray Absorptiometry (DEXA), disease activity parameters.