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

Abstract

(2015) Relationship between physical function, disease activity, spinal mobility and bone parameters (trabecular bone score and bone mineral density) in ankylosing spondylitis patients, Biotechnology & Biotechnological Equipment, 29:5, 956-962, DOI: 10.1080/13102818.2015 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 À 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) D 1.44, 1.05À1.97, p D 0.024) and TBS T-score < À1.00 (OR D 1.55, 1.11À2.16, p D 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.

What Role Does Trabecular Bone Score Play in Chronic Inflammatory Rheumatic Diseases?

“…Moreover, more evident alterations are also reported in bone microarchitecture in older patients, without significant differences between genders. There was an inverse correlation between the mobility scores and the three bone parameters (TBS, BMD, and T-score femoral), showing a relationship between the state of skeletal health and vertebral functional deterioration (50).…”

“…The lumbar spine BMD did not differ between AS and HS patients, whilst there was a decrease in the hip T-score in AS patients (p = 0.02) (44). Several studies reported a 25% OP prevalence in AS patients and from 10 to 43% radiographic vertebral fractures (17,18,(47)(48)(49)(50)(51).…”

“…New bone formation, which includes the development of syndesmophytes and ankylosis of the spine, is almost pathognomonic for AS (47)(48)(49)(50)(51).…”

“…Since AS mainly affects young men and BMD gives falsely increased values, there is often a delay in prevention and/or treatment of OP in this condition. Therefore, appropriate bone assessment to determine bone strength, microstructure and any ossifications is a must to start correct treatment in routine practice (17,18,(47)(48)(49)(50)(51).…”

“…Ivanova et al evaluated the relationship between physical function, disease activity, spine mobility, and bone parameters, TBS and BMD, in AS patients (50). The study concluded that lumbar BMD can be affected by osteoproliferation and that, despite this, AS patients have a lower TBS score than HS.…”