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

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.

Trabecular Bone Score (TBS) in Patients with Early Ankylosing Spondylitis—Limited Utility

“…The effect of age, disease duration, radiological advancement, and disease activity on bone architecture disorders has been found in several studies. Patients with less advanced radiological changes assessed by mSASSS had better TBS [15,24,[26][27][28]; therefore, better TBS results were shown by younger patients [14,26] and patients with shorter duration of the disease [28]. Similarly, the influence of high disease activity-as assessed by ASDAS [26], inflammatory markers [24,26,28], and active radiological changes in MR [29]-was proven to result in lower TBS values.…”

“…Patients with less advanced radiological changes assessed by mSASSS had better TBS [15,24,[26][27][28]; therefore, better TBS results were shown by younger patients [14,26] and patients with shorter duration of the disease [28]. Similarly, the influence of high disease activity-as assessed by ASDAS [26], inflammatory markers [24,26,28], and active radiological changes in MR [29]-was proven to result in lower TBS values. Importantly, the relationship between disease activity and TBS value has been demonstrated in a prospective study [26].…”

“…TBS in AS patients was assessed in several studies. Reported ranges of low TBS (<1.31) in AS patients ranged between 7 and 87.5% [13][14][15][24][25][26], with disturbed microarchitecture (TBS < 1.23) reported as between 9 and 47.5% of AS patients [13,14,24,25] and partially disturbed microarchitecture (TBS ≥ 1.23 and <1.31) as between 10 and 40% of AS patients [13,14,24,25]. This large discrepancy is due to the wide variety of patients included in the studies conducted so far.…”

“…The effect of age, disease duration, radiological advancement, and disease activity on bone architecture disorders has been found in several studies. Patients with less advanced radiological changes assessed by mSASSS had better TBS [15,24,[26][27][28]; therefore, better TBS results were shown by younger patients [14,26] and patients with shorter duration of the disease [28]. Similarly, the influence of high disease activity-as assessed by ASDAS [26], inflammatory markers [24,26,28], and active radiological Among the assessed risk factors for the occurrence of BMD and bone microarchitectural disorders, the univariate analysis showed significantly lower values of TBS (p = 0.047) and TBS T-score (p = 0.037) in biologically treated patients compared to patients not treated biologically (Table 2).…”

Review of the Clinical Applications of Trabecular Bone Score

“…Other studies have also report that TBS accurately diagnosed axial osteoporosis in the early stages of AS, while BMD is not a reliable tool. Moreover, TBS is reported to be capable of predicting spine fractures independent of FRAX in AS patients [45][46][47].…”