ABSTRACT
To determine bone mineral density [BMD] in patients with mild ankylosing spondylitis [AS], to establish the prevalence of vertebral fractures and fracture risk in these patients, and to determine the relationship between BMD and vertebral fractures. Twenty patients were compared with five healthy subjects were included in the study as a control group. Bone mineral density [BMD] was evaluated at the lumbar spine, forearm and femoral neck by dual X-ray absorptiometry [DXA] and A clinical index of disease activity [BASDAI; Bath Ankylosing Spondylitis Activity Index] was also evaluated and plain radiographs of the thoracic and lumbar spine were obtained in all subjects. In patients with AS, BMD was reduced in both the lumbar spine T score -1.0700 +/- 1.9572] and femoral neck [T score -1.3850 +/- 1.2999] and forearm [T score-.9150 +/- 7969] There was no correlation between BMD of the lumbar spine, forearm or femoral neck and duration of disease in patients with AS. four of 20 [20%] patients with AS had a vertebral fracture. Patients with AS with fractures were not significantly older [mean age 34.0 +/- 2.120P=0.301], but had significantly longer disease duration [7.4500 +/- 1.1459, P<0.05] than patients without fractures. No significant correlation between indices of disease activity [ESR and BASDAI] and vertebral fractures in patients with AS. No significant correlation was observed between BMD of the lumbar spine, forearm or femoral neck and vertebral fractures in patients with AS. In addition, there was no significant difference in the lumbar spine, forearm or femoral neck BMD in AS patients with fractures compared with those without. Osteopenia of spine, forearm and femur and vertebral fractures are a feature of mild AS. However, there was no correlation between BMD and vertebral fractures in these patients. AS patients with mild disease had a higher risk of fractures compared with the normal population and this increased with the duration of disease