Relationship between physical function, disease activity, spinal mobility and bone parameters (trabecular bone score and bone mineral density) in ankylosing spondylitis patients

• Published in: Biotechnology, biotechnological equipment biotechnological equipment, 2015-09, Vol.29 (5), p.956-962
• Main Authors: Ivanova, Mariana, Manolova, Irena, Boyadzhieva, Vladimira, Stoilov, Rumen, Dimitrov, Nedko, Stoilov, Nikolay, Aubry-Rozier, Berengere, Rashkov, Rasho, Hans, Didier
• Format: Article
• Language: English
• Subjects: Ankylosing spondylitis; Biomedical materials; Bone density; Bone mineral density; Cancellous bone; Computer architecture; disease activity; Dual energy X-ray absorptiometry; Femur; Mobility; Osteoporosis; Parameters; physical function; spinal mobility; Spine; Spine (lumbar); trabecular bone score
• ISSN: 1310-2818; 1314-3530
• DOI: 10.1080/13102818.2015.1057525

This study aimed to evaluate the relationship between physical function, disease activity, spinal mobility and bone parameters in ankylosing spondylitis (AS) patients. Fifty patients (27 men and 23 women) were examined. The clinical assessment included Bath AS Disease Activity Index, AS Disease Activity Score, Bath AS Functional Index, Bath AS Metrology Index (BASMI). Lumbar spine and femoral neck bone mineral density (BMD), spinal trabecular bone score (TBS) and the TBS T-score were calculated by dual-energy X-ray absorptiometry. Prevalence rates for osteoporosis and osteopaenia were 14% and 36%, respectively and for partially and fully degraded microarchitecture - 34% and 16%, respectively. A similar inverse correlation was observed between BASMI and TBS, TBS T-score and femoral BMD bone parameters, which were significantly lower in patients ≥45 years of age. No significant correlations were detected between any bone parameter and indicators of disease activity and physical function. Patients with a disease duration of ≥10 years tended to exhibit either normal or elevated spine BMD. Femoral BMD was lower in men. The higher BASMI was associated with an increased likelihood of TBS < 1.350 (odds ratio (OR) = 1.44, 1.05-1.97, p = 0.024) and TBS T-score < -1.00 (OR = 1.55, 1.11-2.16, p = 0.01). In summary, lumbar spine BMD can be erroneously influenced by osteoproliferation, unlike the TBS and TBS T-score. The limitations in spinal mobility predicted abnormal results for these two TBS parameters. TBS may be a better indicator of bone health than BMD in AS.