Costovertebral joint involvement in patients with axial spondyloarthritis.

OBJECTIVES: To evaluate costovertebral joint involvement in patients with axial spondyloarthritis (axSpA) and to assess its association with disease features. METHODS: We included 150 patients from the Incheon Saint Mary's axSpA observational cohort who underwent whole spine low-dose computed tomography (ldCT). Costovertebral joint abnormalities were scored by two readers on a scale of 0-48 based on the presence or absence of erosion, syndesmophyte, and ankylosis. The interobserver reliability of costovertebral joint abnormalities was assessed using intraclass correlation coefficients (ICCs). Associations between costovertebral joint abnormality scores and clinical variables were evaluated using a generalized linear model. RESULTS: Two independent readers found costovertebral joint abnormalities in 74 (49%) patients and 108 (72%) patients. The ICCs of scores for erosion, syndesmophyte, ankylosis, and total abnormality were 0.85, 0.77, 0.93, and 0.95, respectively. For both readers, total abnormality score was correlated with age, symptom duration, Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath AS functional index (BASFI), CT syndesmophyte score (CTSS), and number of bridging spines. Multivariate analyses showed age, ASDAS, CTSS to be independently associated with total abnormality scores in both readers. The frequency of ankylosed costovertebral joint was 10.2% (reader 1) and 17.0% (reader 2) in patients without radiographic syndesmophytes (n=62), and 10.3% (reader 1) and 17.2% (reader 2) in patients without radiographic sacroiliitis (n=29). CONCLUSIONS: Costovertebral joint involvement was common in patients with axSpA, even in the absence of radiographic damage. LdCT is recommended for evaluating structural damage in patients with clinically suspected costovertebral joint involvement.

Prevalence and Associated Factors of Facet Joint Ankylosis in Patients With Axial Spondyloarthritis.

OBJECTIVE: To investigate the prevalence of facet joint ankylosis in the whole spine in axial spondyloarthritis (axSpA) using low-dose computed tomography (LDCT), and to identify factors associated with facet joint ankylosis. METHODS: Whole spine LDCT images from 161 patients with axSpA were examined, and the presence of facet joint ankylosis was assessed (right and left, C2-S1) by 2 readers. Facet joint ankylosis was scored from 0 to 46. Structural damage of vertebral body was assessed using CT Syndesmophyte Score (CTSS). Factors associated with ankylosed facet joint scores for the whole spine were identified using a generalized linear model with a negative binomial distribution. RESULTS: Seventy-nine patients (49%) and 70 patients (43%; reader 1 and reader 2, respectively) had ≥ 1 ankylosed facet joint. Facet joint ankylosis was most common in the thoracic spine. The mean score of facet joint ankylosis for the whole spine was 6.6 (SD 11.2) in reader 1 and 4.2 (SD 8.4) in reader 2. Whole spine facet joint ankylosis score positively correlated with Ankylosing Spondylitis Disease Activity Score (ASDAS) and CTSS. In multivariable analysis, the ankylosed facet joint score was associated with ASDAS, sacroiliitis, CTSS, and a history of uveitis in both readers. Uveitis history, ASDAS, and CTSS were associated with whole spine facet joint ankylosis score in subgroup analysis of only radiographic axSpA. CONCLUSION: The prevalence of ankylosed facet joints is high in axSpA, especially in the thoracic segment. The whole spine ankylosed facet joint score is significantly associated with a history of uveitis, ASDAS, sacroiliitis, and syndesmophyte score.

Clinical efficacy of alternative TNF inhibitor and secukinumab between primary non-responder and secondary non-responder of prior TNF inhibitor in ankylosing spondylitis.

OBJECTIVES: To compare the drug retention times and clinical efficacy of alternative tumour necrosis factor inhibitors (TNFi) and secukinumab in primary and secondary non-responders with ankylosing spondylitis (AS). METHODS: AS patients treated with biologics and enrolled in the Korean College of Rheumatology Biologics registry were examined. Patients who did not respond to previous TNFi treatment were defined as primary and secondary non-responders. Data regarding drug discontinuation and clinical efficacy were collected after 1 year. Kaplan-Meier and Cox regression analyses were performed to compare drug survival and associated factors. Logistic regression analyses were conducted to compare the clinical efficacy secukinumab with that of alternative TNFi. RESULTS: In total, 124 patients (83 receiving alternative TNFi and 41 receiving secukinumab) had biologic changes due to clinical inefficacy. Drug retention rates in the alternative TNFi and secukinumab groups were similar (P = 0.096). However, subgroup analyses including only secondary non-responders revealed that secukinumab users showed a higher hazard ratio (HR) for drug discontinuation (HR = 3.77, P = 0.045). In addition, secukinumab was negatively associated with achieving BASDAI50 or a major improvement in the ASDAS. CONCLUSION: Alternative TNFi showed better drug retention and clinical efficacy in AS patients experiencing previous TNFi failure, in secondary non-responders. Therefore, alternative TNFi may be a more suitable treatment for secondary non-responders.

Physical activity is associated with physical and global function in patients with axial spondyloarthritis, independent of disease activity.

OBJECTIVES: To investigate whether physical activity is independently associated with physical and global function in patients with axial spondyloarthritis (axSpA), and to analyse the relationship between subtypes of physical activity (work, transport, and recreation) and functional impairment. METHODS: One-hundred-and-eighty-five patients were included. Physical function was assessed using BASFI, and global function was assessed using the ASAS health index (HI). Physical activity was measured using the Global Physical Activity Questionnaire. Levels of physical activity were categorised as low, moderate or high. The associations between levels of physical activity and the BASFI and ASAS HI scores were analysed using multivariate regression analysis. RESULTS: Of the 185 patients, 46, 63 and 76 reported low, moderate and high levels of physical activity, respectively. There was a negative correlation between the BASFI and total physical activity. Multivariate linear regression analysis revealed that a high level of physical activity was independently associated with BASFI after adjusting for age, ASDAS. sacroiliitis and syndesmophyte number (ß (95% CI) =-0.88 (-1.49--0.26); p=0.006). One-hundred-and-forty-six had good global functioning (ASAS HI≤5). Multivariate logistic regression analysis revealed that moderate physical activity was independently associated with good global functioning (OR (95% CI) = 2.82 (1.02-7.86); p = 0.047). Recreational activity, but not work- and transport-related activity, showed a significant relationship with ASAS HI scores (ß (95% CI) =-0.55 (-1.02-0.08); p = 0.023). CONCLUSIONS: Physical activity in those with axSpA is associated independently with physical and global functioning. Among the subtypes of physical activity, recreational activity is related to global functioning.

Increased risks of aortic regurgitation and atrial fibrillation in radiographic axial spondyloarthritis patients: a 10-year nationwide cohort study.

Background: To compare the incidences of aortic regurgitation, atrial fibrillation (AF), and atrioventricular (AV) block II-III between radiographic axial spondyloarthritis (r-axSpA) patients and the general population (GP). Methods: National Health Insurance Services data were used. R-axSpA patients (N = 8877) and the age- and sex-matched GP (N = 26,631) were followed from August 2006 to December 2019. Incidence rates and standardized incidence ratios (SIRs) of aortic regurgitation, AF, and AV block II-III were compared between these groups. Ten-year incidence rates and hazard ratios (HRs) were calculated by the Kaplan-Meier method and Cox regression analysis. Results: Incidence rates of aortic regurgitation, AV block II-III, and AF in the r-axSpA group were 0.42, 0.21, and 4.0 per 1000 person-years (PYs), respectively. In the r-axSpA group, the SIR for aortic regurgitation was highest among 40- to 49-year-old men (4.11). Incidence rates of aortic regurgitation and AF were higher in the r-axSpA group than in the GP group (0.42 versus 0.18 per 1000 PYs 4.00 versus 3.13 per 1000 PYs, both p < 0.001, respectively), whereas the difference was insignificant for AV block II-III (0.21 versus 0.14 per 1000 PYs, p = 0.222). In multivariate analysis, r-axSpA was associated with a higher hazard (risk) for the development of aortic regurgitation and AF [HR (95% confidence interval) = 2.55 (1.49-4.37) and 1.20 (1.04-1.39), respectively], but the difference was insignificant for AV block II-III [HR (95% confidence interval) = 1.17 (0.59-2.31)]. Conclusions: Compared with the GP, r-axSpA patients are at increased risk of aortic regurgitation and AF, but not AV block II-III. These patients should be carefully monitored for occurrence of aortic regurgitation and AF.

Association between facet joint ankylosis and functional impairment in patients with radiographic axial spondyloarthritis.

OBJECTIVES: To investigate the occurrence of facet joint ankylosis in the spine of patients with radiographic axial spondyloarthritis (r-axSpA) using low dose computed tomography (ldCT), and to examine the association between facet joint ankylosis and functional impairment. METHODS: A group of 126 patients with r-axSpA was selected from Incheon Saint Mary's axSpA observational cohort and whole spine ldCT data were examined. Facet joint (right and left, C2-S1) ankylosis was scored from 0-46 (total). The presence of facet joint ankylosis was assessed by two readers, each blinded to the patient data. The inter-reader reliability of facet joint ankylosis scoring was assessed using intraclass correlation coefficients (ICCs). The CT Syndesmophyte Score (CTSS) was assessed. Lumbar spinal mobility was evaluated using the modified Schober test. Functional impairment was measured using the Bath AS functional index (BASFI). RESULTS: The ICCs of ankylosed facet joint scores at the cervical, thoracic, lumbar and whole spine were 0.84, 0.88, 0.92 and 0.90, respectively. Facet joint ankylosis was most common in the thoracic spine. Scores for the whole spine correlated positively with the ASDAS, mSASSS and the syndesmophyte score. Multivariate analysis revealed that facet joint ankylosis was significantly associated with decreased lumbar motion. For both readers, the scores for the whole spine were independently associated with BASFI after adjusting for syndesmophyte score and disease activity. CONCLUSIONS: Facet joint ankylosis in patients with r-axSpA was associated with functional impairment and spinal mobility. Facet joints should be incorporated into a structural damage assessment method.

Retention rate and effectiveness of secukinumab vs TNF inhibitor in ankylosing spondylitis patients with prior TNF inhibitor exposure.

OBJECTIVES: The choice of second-line biologics for AS patients previously treated with a TNF inhibitor (TNFi) remains unclear. Here, we compared drug retention and clinical efficacy between AS patients who switched biologics to secukinumab and those who switched to a different TNFi. METHODS: AS patients enrolled in the Korean College of Rheumatology BIOlogics registry were included, and patients with non-radiographic axial spondyloarthritis were excluded. Patients with previous TNFi exposure were divided into the secukinumab group and the TNFi switching group. Drug retention and clinical efficacy [BASDAI50, Assessment of Spondylo-Arthritis International Society (ASAS)20, ASAS40, AS disease activity score (ASDAS) <2.1, ASDAS clinically important improvement and ASDAS major improvement] were assessed at the 1 year follow-up. Propensity score (PS)-matched and covariate-adjusted logistic regression analyses were performed. RESULTS: Two hundred and forty-six had available 1 year follow-up data. Secukinumab as third- or later-line biologic was more frequent than alternative TNFi (54% vs 14%). PS-matched and multiple covariate-adjusted analyses showed that the odds ratio (OR) for drug discontinuation was comparable between the secukinumab and TNFi switching groups [OR 1.136 (95% CI 0.843, 1.531) and 1.000 (95% CI 0.433-2.308), respectively]. The proportion of patients who achieved BASDAI50 was also comparable between the two groups [OR 0.833 (95% CI 0.481, 1.441) in PS-matched analysis]. Other clinical efficacy parameters were also comparable. In the subgroup analysis of AS patients with previous TNFi discontinuation due to ineffectiveness, all clinical efficacy parameters were comparable between the two groups. CONCLUSION: In AS patients with previous exposure to a TNFi, switching biologics to secukinumab and switching to an alternative TNFi resulted in comparable drug retention and clinical efficacy.

A 2-year longitudinal study of bone health in adolescent patients with axial spondyloarthritis.

PURPOSE: Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that primarily affects the axial skeleton and typically has an early onset. Although earlier onset is associated with worse prognosis, there have been few studies of bone mineral density (BMD) in adolescent patients with axSpA. METHODS: We analysed the clinical characteristics of 43 adolescent patients with axSpA at a baseline assessment and at a follow-up 2 years later. The baseline assessment included age, disease duration, treatment agents, and clinical, radiologic, and laboratory data. BMD of the lumbar spine, femoral neck, and total hip were measured by dual-energy X-ray absorptiometry during both the baseline assessment and the 2-year follow-up. We performed multivariate linear regression analyses to identify factors independently associated with BMD. We analysed the associations between changes in BMD and reductions in inflammatory markers. RESULTS: The average age of participants was 17.9 years and the mean disease duration was 2.2 years. Of the 43 patients, 10 (23%) had low BMD at any site (lumbar spine, femoral neck, and/or total hip). At baseline, multivariate analysis showed that body mass index (BMI), erythrocyte sedimentation rate (ESR), and spinal structural damage were associated with lumbar spine Z-scores. Increases in BMD in the lumbar spine were correlated with reductions in ESR (r = 0.40, P = 0.02) and C-reactive protein (CRP) (r = 0.40, P = 0.02). Increases in BMD in the total hip were correlated with reductions in CRP (r = 0.38, P = 0.03). CONCLUSION: In adolescent axSpA patients, bone health was associated with systemic inflammation and the severity of structural damage. Reduced systemic inflammation was associated with improvements in bone health.

Trabecular bone loss contributes to radiographic spinal progression in patients with axial spondyloarthritis.

OBJECTIVES: To investigate the longitudinal relationship between trabecular bone loss and spinal progression in axial spondyloarthritis (axSpA). METHODS: Patients enrolled in the Incheon Saint Mary's axSpA prospective observational cohort were evaluated. The number of syndesmophytes was assessed by two trained readers at baseline and at 2 and 4 years follow-up. Trabecular bone loss was assessed using the trabecular bone score (TBS). Disease activity measures included the BASDAI, ASDAS, CRP, and ESR. The relationship between trabecular bone loss and radiographic damage was investigated using generalized estimating equation models with 2 year time lags. RESULTS: Of the 245 patients included (80% males; mean (SD) age, 37 (12) years), 26 (11%) had mild trabecular bone loss (1.23-1.31) and 25 (10%) had severe trabecular bone loss (≤1.23) at baseline. Trabecular bone loss was associated with longitudinal radiographic spinal progression. Those with severe trabecular bone loss at baseline had an average 0.42 more syndesmophytes/2 years than those with normal TBS. Multivariate analysis revealed that severe trabecular bone loss compared with normal TBS resulted in an additional 0.4 syndesmophytes over 2 years. Adjusting for significant clinical factors revealed that both mild and severe trabecular bone loss were independent risk factors for new syndesmophyte formation over the next 2 years (OR [95% CI] = 2.4 [1.1-5.1]) and OR [95% CI] = 4.0 [1.6-9.7], respectively). CONCLUSIONS: Trabecular bone loss is longitudinally associated with spinal progression of axSpA. The more severe the trabecular bone loss, the stronger the effect on the progression of the spine.

Longitudinal Association Between Trabecular Bone Loss and Disease Activity in Axial Spondyloarthritis: A 4-year Prospective Study.

OBJECTIVE: To investigate whether trabecular bone loss is longitudinally associated with disease activity measures in patientswith axial spondyloarthritis (axSpA). METHODS: Data from patients enrolled in the Incheon Saint Mary's axSpA prospective observational cohort were evaluated. Trabecular bone loss was assessed using the trabecular bone score (TBS). The relationship between TBS and disease activity measures [Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)] was investigated using generalized estimating equation (GEE) models. RESULTS: Four-year followup data from 240 patients (80% males, mean age 37 ± 12 yrs) were evaluated. At baseline, higher disease activity according to ASDAS-ESR and ASDAS-CRP showed a trend toward lower TBS (p = 0.003 and p = 0.016, respectively). Univariate GEE analyses showed a significant association between TBS and disease activity measures over time, with the exception of BASDAI. Univariate analysis showed a longitudinal association between TBS and age, smoking, and spinal structural damage. In multivariate GEE analysis, ASDAS-ESR, ASDAS-CRP, ESR, and CRP were longitudinally associated with TBS after adjustment for confounding factors. ASDAS scores and inflammatory markers were longitudinally associated with TBS in patients with ankylosing spondylitis (AS; 79%), but not in patients with nonradiographic axSpA (nr-axSpA). BASDAI scores showed no relationship with TBS in either the AS or nr-axSpA groups. CONCLUSION: Trabecular bone loss in patients with axSpA, assessed using the TBS, showed a longitudinal association with ASDAS scores and inflammatory markers.

High serum uric acid level is associated with greater handgrip strength in the aged population.

BACKGROUND: We aimed to investigate the association of serum UA level with muscle strength assessed by handgrip strength (HGS) in a large Korean adult population. METHODS: Cross-sectional data were obtained from the seventh Korea National Health and Nutrition Examination Survey (KNHANES) 2016. The KNHANES 2016 study included 8150 subjects, of whom 4230 subjects were analyzed in this study. The association between serum UA level and HGS was investigated with adjustment for confounding factors. RESULTS: Serum UA was divided into sex-specific tertiles After adjustment for potential confounding factors, HGS was significantly greater in the high serum UA group (the third tertile) than in the low UA group (the first tertile) in the elderly (age ≥ 60 years) population (coefficient ß [95% confidence interval (CI)] = 1.017 [0.115-1.920]). When the elderly population was subdivided according to the presence of metabolic syndrome (metS), the impact of UA remained significant only in individuals with metS. In the aged population, high serum UA level reduced the risk for low HGS (OR, 95% CI = 0.69, 0.48-0.98, p = 0.041) only in male subjects. CONCLUSIONS: A population-based cross-sectional survey in Korea revealed that high serum UA level is associated with increased HGS in the aged population. The antioxidant property of UA may enhance muscle strength, especially in the elderly population.

Factors associated with low trabecular bone scores in patients with end-stage kidney disease.

The trabecular bone score (TBS) is a textural index that indirectly assesses bone trabecular microarchitecture using lumbar spine images obtained by dual-energy X-ray absorptiometry (DXA). This study compared the TBS of patients with end-stage kidney disease (ESKD) with that of matched controls to identify risk factors associated with a low TBS. TBS and bone mineral density (BMD) were assessed in ESKD patients (n = 76) and age- and sex-matched control subjects (n = 76) using DXA. The TBS of both groups was then compared, and risk factors associated with a low TBS (defined as ≤ 1.31) were evaluated. The mean TBS in the ESKD group was significantly lower than that in the control group (1.34 ± 0.15 vs. 1.43 ± 0.08, respectively; p < 0.001). More subjects in the ESKD group had a low TBS [34.2% (ESRD) vs. 5.3% (controls); p < 0.001]. The TBS was negatively correlated with age, alkaline phosphatase and C-reactive protein levels, and dialysis vintage, and positively correlated with BMD at the lumbar spine, femoral neck, and hip. Multivariate analysis identified lower estimated glomerular filtration rate and increased C-reactive protein levels as being significantly associated with a low TBS. In conclusion, ESKD patients had abnormal bone microarchitecture (as assessed by the TBS). The TBS was positively correlated with BMD. Renal function and inflammatory marker levels were independently associated with a low TBS. Thus, TBS may be a useful clinical tool for assessing cancellous bone connectivity in ESKD patients.

Inflammation on spinal magnetic resonance imaging is associated with poor bone quality in patients with ankylosing spondylitis.

Objective: To determine the association between inflammatory lesions on spinal magnetic resonance imaging (MRI) and trabecular bone score (TBS) in patients with ankylosing spondylitis (AS). Methods: Ninety-seven patients with AS underwent spine MRI and dual energy X-ray absorptiometry of the lumbar spine to measure TBS and bone mineral density (BMD). Bone marrow edema (BME) on MRI was considered an inflammatory lesion. The presence, depth (>1 cm), and intensity of BME on MRI were scored for the 1st-4th lumbar spine segments. Inflammatory markers and spinal structural damage scores at the time of MRI examination were recorded. The association between inflammatory activity score on MRI and TBS was evaluated. Results: Among the 97 patients, 52 had BME on spinal MRI (L1-L4). The mean TBS values were 1.38 ± 0.11 and 1.43 ± 0.11 for patients with and without BME, respectively (p = .022). Total inflammatory activity scores on spinal MRI correlated negatively with TBS, but not with BMD. Patients with a TBS value representing a high fracture risk had more deep BME (>1 cm) (p = .048) on MRI. After adjustment for age, symptom duration, and lumbar spinal structural damage, the TBS decreased as inflammation severity on MRI increased (p = .026). Discussion: In AS patients, inflammation on spinal MRI was negatively correlated with TBS. The severity of local bone inflammation in the spine was associated with poor bone quality. These findings suggest that the control of active bone inflammation may be effective for preventing osteoporosis in AS patients.

Low bone mineral density predicts the formation of new syndesmophytes in patients with axial spondyloarthritis.

BACKGROUND: This study aimed to investigate whether the presence of low bone mineral density (BMD) in patients with axial spondyloarthritis (axSpA) predicts formation of new syndesmophytes over 2 years. METHODS: One hundred and nineteen patients fulfilling the imaging arm of the Assessment of SpondyloArthritis International Society axSpA criteria were enrolled. All patients were under 50 years of age. The modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) was assessed by two trained readers blinded to the patients' data. BMD (lumbar spine, femoral neck or total hip) at baseline was assessed using dual-energy absorptiometry. Low BMD was defined as Z score ≤ - 2.0. Spinal radiographic progression was defined as worsening of the mSASSS by ≥ 2 points over 2 years. Logistic regression analyses were performed to identify predictors associated with development of new syndesmophytes and spinal radiographic progression. RESULTS: At baseline, 19 (16%) patients had low BMD. New syndesmophytes had developed in 22 (21%) patients at 2-year follow-up. New syndesmophyte formation after 2 years occurred more in patients with low BMD than in those with normal BMD (p = 0.047). In the multivariable analysis, current smoking, existing syndesmophytes and low BMD at baseline were associated with spinal radiographic progression (OR (95% CI) 3.0 (1.1, 7.7), 4.6 (1.8, 11.8) and 3.6 (1.2, 11.2), respectively). The presence of syndesmophytes at baseline and low BMD were predictors of new syndesmophytes over the following 2 years (OR (95% CI) 5.5 (2.0, 15.2) and 3.6 (1.1, 11.8), respectively). CONCLUSIONS: Low BMD and existing syndesmophytes at baseline were independently associated with the development of new syndesmophytes in young axSpA patients.

Differences in quality of life determinants according to the presence of fibromyalgia in middle-aged female patients with systemic lupus erythematosus: a multicenter, cross-sectional, single-ethnicity cohort.

OBJECTIVE: The purpose of this study was to identify whether determinants of health-related quality of life (HRQoL) in middle-aged female patients with systemic lupus erythematosus (SLE) differed according to the presence or absence of fibromyalgia. METHODS: One hundred and fifty-two patients with SLE and 139 healthy controls (HCs) completed the Medical Outcomes Study 36-Item Short Form (SF-36) and EuroQol EQ-5D questionnaires about HRQoL. Disease activity and cumulative disease damage were assessed with standard indices. Sleep quality was assessed using the Korean version of the Pittsburgh Sleep Quality Index (K-PSQI). RESULT: The mean EQ-5D and physical and mental components of SF-36 were lower in SLE patients with fibromyalgia (n = 41) than in those without fibromyalgia (n = 111) and HCs. The scores in all eight domains of the SF-36 were lower in SLE patients with fibromyalgia than in patients without fibromyalgia and HCs. Poor sleep (defined as a K-PSQI > 5) was reported by 85% of SLE patients with fibromyalgia, by 51% of patients without fibromyalgia, and by 33% of HCs. Multivariate logistic regression analysis showed that lower educational level, cumulative organ damage severity and poor sleep quality were independent determinants of HRQoL in SLE patients with fibromyalgia, whereas disease activity, sleep quality and depressive mood were independent determinants of HRQoL in those without fibromyalgia. CONCLUSION: Poor sleep quality is the common independent risk factor for poor HRQoL in both middle-aged SLE patients with fibromyalgia and without fibromyalgia. Sleep quality improvement may improve HRQoL in female SLE patients, even in those without fibromyalgia.

Associations between trabecular bone score and vertebral fractures in patients with axial spondyloarthritis.

OBJECTIVES: To compare trabecular bone scores (TBS) between axial SpA (axSpA) patients with and without vertebral fractures and investigate associations between TBS and vertebral fractures. METHODS: Two hundred and fifty-five patients fulfilling the imaging arm of the Assessment of SpondyloArthritis International Society axSpA criteria were enrolled. TBS and BMD were assessed using dual-energy X-ray absorptiometry. Vertebral fracture of the thoracic and lumbar spine was defined according to the Genant criteria. Osteoporosis risk factors, inflammatory markers, DAS and spinal structural damage were also assessed. Univariate logistic regression analysis was performed to identify factors associated with vertebral fractures. RESULTS: There were 31 vertebral fractures in 28/255 axSpA patients (11%). The mean (s.d.) TBS was 1.39 (0.11) and 1.30 (0.13) in patients without and with vertebral fractures, respectively (P < 0.001). BMD in the femoral neck was lower in patients with vertebral fractures (P = 0.027), but BMDs in the lumbar spine and total hip were not. Univariate logistic regression analyses identified old age (⩾50 years), TNF inhibitor treatment, the presence of syndesmophytes and a low TBS (<1.23) as associated with prevalent vertebral fractures [odds ratio (95% CI): 6.9 (2.0, 24.4), 2.4 (1.0, 5.5), 5.5 (2.2, 13.5) and 5.3 (2.0, 14.1), respectively]. TBS has a better discriminatory value than BMD at the total hip for prediction of vertebral fractures in axSpA patients (P = 0.034). CONCLUSION: Similar to individuals with primary osteoporosis, axSpA patients with vertebral fractures have a lower TBS. This suggests that TBS has the potential to predict future vertebral fractures in patients with axSpA.

Trabecular bone score as an assessment tool to identify the risk of osteoporosis in axial spondyloarthritis: a case-control study.

OBJECTIVES: To compare the trabecular bone score (TBS) between patients with axial spondyloarthritis (axSpA) and matched normal controls and identify risk factors associated with a low TBS. METHODS: TBS and BMD were assessed in the two groups (axSpA and control) using DXA. Osteoporosis risk factors and inflammatory markers were also assessed. Disease activity and radiographic progression in the sacroiliac joint and spine were evaluated in the axSpA group. Multivariate linear regression analysis was performed to identify risk factors associated with TBS. RESULTS: In the axSpA group, 248 subjects were enrolled; an equal number of age- and sex-matched subjects comprised the control group. The mean TBS was 1.43 (0.08) and 1.38 (0.12) in the control and axSpA groups, respectively (P < 0.001); BMD at the lumbar spine did not differ between the two groups. The TBS was negatively correlated with ESR and CRP levels in the axSpA group only (P < 0.001 and P = 0.007, respectively). Syndesmophytes in the axSpA group was associated with lower TBS (P < 0.001) but higher lumbar BMD (P = 0.021) vs controls. In the multivariate analyses, ESR, CRP and spinal radiographic progression were significantly associated with TBS. CONCLUSION: TBS assessments revealed poor bone quality in patients with axSpA compared with the matched controls. In axSpA, systemic inflammatory markers were negatively correlated with TBS and spinal radiographic progression and inflammatory markers were independently correlated with low TBS. TBS may, therefore, be a useful clinical tool to identify the risk of osteoporosis in patients with axSpA.

Severity of Sacroiliitis and Erythrocyte Sedimentation Rate are Associated with a Low Trabecular Bone Score in Young Male Patients with Ankylosing Spondylitis.

OBJECTIVE: To examine factors related to a low trabecular bone score (TBS) and the association between TBS and vertebral fractures in patients with ankylosing spondylitis (AS). METHODS: One hundred patients (all male, aged < 50 yrs) who fulfilled the modified New York criteria for the classification of AS were enrolled. The TBS and bone mineral density (BMD) were assessed using dual-energy X-ray absorptiometry. Clinical variables, inflammatory markers, and the presence of vertebral fractures were also assessed. Sacroiliitis grade and spinal structural damage were measured using the modified New York criteria and the Stoke Ankylosing Spondylitis Spine Score (SASSS). RESULTS: The mean TBS was 1.38 ± 0.13. The TBS showed a positive correlation with BMD at the lumbar spine, femoral neck, and total hip. TBS negatively correlated with SASSS, whereas BMD at the lumbar spine showed a positive correlation. A significant decrease in TBS values was observed in patients with spinal structural damage (p = 0.001). Univariate analysis identified disease duration, erythrocyte sedimentation rate (ESR), sacroiliitis grade, and SASSS as being associated with TBS. Multivariate analysis identified ESR and sacroiliitis grade as being independently associated with TBS (p = 0.006 and p < 0.001, respectively). Ten patients had morphometric vertebral fractures. The mean TBS was lower in patients with vertebral fractures than in age-matched patients without fractures (p = 0.028). Lower TBS predicted vertebral fractures (area under curve = 0.733, cutoff = 1.311). CONCLUSION: The TBS in young male patients with AS is associated with the ESR and severity of sacroiliitis. The TBS may be useful as a tool for assessing osteoporosis in AS.

Gender-Specific Associations between Low Skeletal Muscle Mass and Albuminuria in the Middle-Aged and Elderly Population.

Objective This study assessed gender-specific associations between low muscle mass (LMM) and albuminuria. Methods Data from the Korea National Health and Nutrition Examination Survey 2011 were employed. The study consisted of 1,087 subjects (≥50 years old). Skeletal muscle index (SMI) was defined as the weight-adjusted appendicular skeletal muscle mass. Mild LMM and severe LMM were defined as SMI that were 1-2 and >2 standard deviations below the sex-specific mean appendicular skeletal muscle mass of young adults, respectively. Increased albuminuria was defined as albumin-to-creatinine ratio ≥30mg/g Results Men with mild and severe LMM were significantly more likely to have increased albuminuria (15.2% and 45.45%, respectively) than men with normal SMI (9.86%, P<0.0001), but not women. Severe LMM associated independently with increased albuminuria in men (OR=7.661, 95% CI=2.72-21.579) but not women. Severe LMM was an independent predictor of increased albuminuria in hypertensive males (OR=11.449, 95% CI=3.037-43.156), non-diabetic males (OR=8.782, 95% CI=3.046-25.322), and males without metabolic syndrome (MetS) (OR=8.183, 95% CI=1.539-43.156). This was not observed in males without hypertension, males with diabetes or MetS, and all female subgroups. Conclusion Severe LMM associated with increased albuminuria in men, especially those with hypertension and without diabetes or MetS.