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Is Spinal Mobility in Patients With Spondylitis Determined By Age, Structural Damage, and Inflammation?

Wiley
Arthritis Care & Research
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Objective: To explore the association between mobility, inflammation, and structural damage in ankylosing spondylitis (AS). Methods: Patients with AS were included in a cross-sectional study in which spinal mobility was measured by the Bath Ankylosing Spondylitis Metrology Index (BASMI) and by the University of Córdoba Ankylosing Spondylitis Metrology Index (UCOASMI), based on an automated motion analysis. Structural damage was measured by the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), and activity by the Ankylosing Spondylitis Disease Activity Score (ASDAS) and the Bath Ankylosing Spondylitis Disease Activity (BASDAI). We analyzed the correlations between variables, as well as interaction by multiple linear regression models to reach a predictive equation. Results: Fifty AS patients, mainly men in their mid-40s and with moderate levels of disease activity and structural damage, were included in the study. BASMI and UCOASMI scores showed a strong correlation (r = 0.89). UCOASMI scores correlated stronger than BASMI with structural damage (r = 0.72 versus r = 0.67) and patient's age (r = 0.68 versus r = 0.56). Correlations of mobility were weaker with disease activity by the ASDAS (r = 0.38) and BASDAI (r = 0.49), and disease duration (r = 0.40). Multiple linear regression showed that factors associated to mobility by UCOASMI were age, the BASDAI, mSASSS, ASDAS (0:<2.1, 1:≥2.1), and disease duration >15 years. The largest weight in the equation corresponded to the mSASSS. The association between the ASDAS and UCOASMI is dependent on disease duration. Conclusion: Mobility in AS is influenced by both structural damage and activity, but definitely also by age and disease duration. Improved mobility should be a relevant target in AS, even more prominently than activity, given its closer relation to structural damage.
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... AxSpA includes two subsets of disease as radiographic axSpA (also known as ankylosing spondylitis) and non-radiographic axSpA (3). AxSpA patients present with symptoms such as limitation of spinal mobility, loss of physical functions, pain, and fatigue (4)(5)(6). ...
... We discovered for the first time that pantothenate has a significant genetic correlation with SpA. As SpA is an autoinflammatory disease, the genetic correlation between SpA and pantothenate is likely to be related to the relationship between pantothenate and inflammation [49,50]. ...
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The aim was to study the genetic correlation and causal relationship between spondyloarthritis (SpA) and blood metabolites based on the large-scale genome-wide association study (GWAS) summary data. The GWAS summary data (3966 SpA and 448,298 control cases) of SpA were from the UK Biobank, and the GWAS summary data (486 blood metabolites) of human blood metabolites were from a published study. First, the genetic correlation between SpA and blood metabolites was analyzed by linkage disequilibrium score (LDSC) regression. Next, we used Mendelian randomization (MR) analysis to perform access causal relationship between SpA and blood metabolites. Random effects inverse variance weighted (IVW) was the main analysis method, and the MR Egger, weighted median, simple mode, and weighted mode were supplementary methods. The MR analysis results were dominated by the random effects IVW. The Cochran’s Q statistic (MR-IVW) and Rucker’s Q statistic (MR Egger) were used to check heterogeneity. MR Egger and MR pleiotropy residual sum and outlier (MR-PRESSO) were used to check horizontal pleiotropy. The MR-PRESSO was also used to check outliers. The “leave-one-out” analysis was used to assess whether the MR analysis results were affected by a single SNP and thus test the robustness of the MR results. Finally, we identified seven blood metabolites that are genetically related to SpA: X-10395 (correlation coefficient = −0.546, p = 0.025), pantothenate (correlation coefficient = −0.565, p = 0.038), caprylate (correlation coefficient = −0.333, p = 0.037), pelargonate (correlation coefficient = −0.339, p = 0.047), X-11317 (correlation coefficient = −0.350, p = 0.038), X-12510 (correlation coefficient = −0.399, p = 0.034), and X-13859 (Correlation coefficient = −0.458, p = 0.015). Among them, X-10395 had a positive genetic causal relationship with SpA (p = 0.014, OR = 1.011). The blood metabolites that have genetic correlation and causal relationship with SpA found in this study provide a new idea for the study of the pathogenesis of SpA and the determination of diagnostic indicators.
... Measurements are, however, complicated by several factors, such as inter-and intrarater reliability issues (10) and the known diurnal variation of symptoms with morning stiffness and improvement of mobility after warm-up (11). Perhaps most importantly, disease activity and pain may lead to temporary restrictions of mobility beyond what is associated with structural changes (12)(13)(14). Flares, especially minor localized flares, seem to be common in AS. In a study of 134 AS patients with a mean of 21 years since symptom onset, 59% of patients reported a minor flare and 12% reported a major, generalized flare over a mean follow-up period of 9 weeks (15). ...
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Objective Normal age‐related decline and temporary restrictions in mobility complicate the understanding of spinal mobility deterioration over time in patients with ankylosing spondylitis (AS). In this study, we aimed to determine whether spinal mobility deterioration occurred linearly in patients with AS. We also aimed to compare patterns of change with corresponding age‐related normal values and analyze variations in temporary fluctuations in mobility measurements over time. Methods We included 111 men and 30 women (median age 20.9 years at symptom onset), who were followed for a median of 34 years since symptom onset. This inclusion resulted in 9,697 spinal mobility measurements for analysis. Individual linear regression models for development of lateral spinal flexion (LSF), the 10‐cm Schober test (ST10), chest expansion (CE), and cervical rotation (CR) were analyzed and compared with normal age‐related decline over time. Results The median values for the constants of all measurements were significantly lower than the norm data. However, LSF, ST10, and CE followed a yearly linear decline comparable to the norm data, whereas CR declined approximately twice as fast as expected from the norm data (beta median −0.62° [25th–75th percentile −1.16, −0.22] and −0.35° [25th–75th percentile −0.35, −0.35], respectively). Temporary fluctuations in LSF and CE were significantly higher during the early phase of the disease, with decreasing residuals over time. Conclusion Based on median constants of our data, mobility restrictions related to AS seem to mainly occur during the first years of disease, indicating a narrow window of opportunity for prevention.
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Axial spondyloarthritis (axSpA) is a rheumatic inflammatory chronic disease that mainly affects the spine, producing inflammation and structural damage at the vertebral level (erosions, syndesmophytes, and bony bridges) [...]
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This paper describes the use of a video-based motion capture system to assess spinal mobility in patients with ankylosing spondylitis (AS). The aim of the study is to assess reliability of the system comparing it with conventional metrology in order to define and analyze new measurements that reflect better spinal mobility. A motion capture system (UCOTrack) was used to measure spinal mobility in forty AS patients and twenty healthy subjects with a marker set defining 33 3D measurements, some already being used in conventional metrology. Radiographic studies were scored using the modified Stoke Ankylosing Spondylitis Spine Score index (mSASSS). Test-retest reliability studies were performed on the same day and over a two-week period. Motion capture shows very high reliability with Intraclass Correlation Coefficient values ranging from 0.89 to 0.99, low Standard Error of the Measurement (0.37-1.33 cm and 1.58°-6.54°), correlating very well with the Bath Ankylosing Spondylitis Metrology Index (BASMI) (p < 0.001) and, in some individual measures (cervical flexion, cervical lateral flexion, back inclination, shoulder-hip angle and spinal rotation), with mSASSS (p < 0.01). mSASSS also added significantly to the variance in multivariate linear regression analysis to certain measures (back inclination, cervical flexion and cervical lateral flexion). Quantitative results obtained with motion capture system using the protocol defined show to be highly reliable in patients with AS. This technique could be a useful tool for assessing the outcome of the disease and for monitoring the evolution of spinal mobility in AS patients.