Performance of bone mineral density and trabecular bone score in assessment of bone quality in Egyptian male patients with ankylosing spondylitis

Abstract

Abstract Background Osteoporosis is a common complication of ankylosing spondylitis (AS) even in the early stages of disease; however, previously published studies have demonstrated large discrepancies in the reported incidence of osteoporosis, based on measurement of bone mineral density (BMD). The aim of the present study was to compare bone quality using trabecular bone score (TBS) between AS patients and healthy controls and to evaluate factors associated with TBS in patients with AS. Results Ankylosing spondylitis patients had significantly lower BMD and T score at the neck of femur and lower total hip BMD than controls (BMD p = 0.010 and 0.032 respectively), (T score p = 0.006 and p = 0.025 respectively). The mean TBS was significantly lower in AS patients than in controls (p < 0.001). Lumbar spine TBS was directly correlated with BMI (p = 0.029) and BMD at the neck of femur (p = 0.016) and BMD of total hip (p = 0.007) while inversely correlated with the Bath AS Metrology Index (BASMI) (p = 0.026), the modified Stoke AS Spinal Score (mSASS) (p = 0.029), ESR (p = 0.031), and CRP (p = 0.033). Conclusion TBS evaluation detected lower bone quality in the lumbar spine in patients with AS when compared with matched controls, while lumbar BMD failed to identify it. These findings encourage the use of TBS as a beneficial tool to recognize the risk of axial osteoporosis as early as possible in AS patients. Also, we recommend its use for regular follow up of drug treatment for those patients.

Keywords

• Ankylosing spondylitis
• Osteoporosis
• Dual energy X-ray absorptiometry
• Trabecular bone score