Obesity Represents a Persisting Health Issue in Axial Spondyloarthritis, Particularly Affecting Socially Disadvantaged Patients.

OBJECTIVE: Obesity is an important comorbidity in axial spondyloarthritis (axSpA); however, the prevalence of obesity in axSpA compared with the general population and associated socioeconomic factors remain unknown. METHODS: This repeated cross-sectional study compared BMI (kg/m2) groups of patients with axSpA to the Swiss population at 3 timepoints (2007, 2012, and 2017). BMI categories were compared by different age, sex, and education categories using the chi-square goodness of fit test. Unpaired, 1-sided t tests were used to compare the BMI in patients with axSpA between the different timepoints. RESULTS: Compared to the general population, patients with axSpA had a higher proportion of overweight and obesity: 18.9% of all patients with axSpA were obese, compared to 11.3% of the Swiss population in 2017. Comparison of BMI groups within sex, age, and education groups consistently showed a trend toward higher rates of overweight and obesity in axSpA. Further, patients with axSpA, especially females, showed a trend of increasing BMI over the studied 10 years. At every time point, overweight and obese patients were significantly more likely to be male, were older, and had higher disease activity than patients with normal weight. Obesity was associated with a deprived socioeconomic status as indicated by a higher proportion of patients with manual labor jobs and lower levels of education. CONCLUSION: The prevalence of obesity was significantly higher among patients with axSpA compared to the Swiss population, with socially disadvantaged individuals being the most affected. There is an urgent need to initiate prevention strategies for obesity in patients with axSpA.

Site-specific assessment of spinal radiographic progression improves detection of TNF blocker-associated disease modification in axial spondyloarthritis: longitudinal observational data from the Swiss Clinical Quality Management Registry.

OBJECTIVES: To analyse whether time-varying treatment with tumour necrosis factor inhibitors (TNFi) in radiographic axial spondyloarthritis (r-axSpA) has a differential impact on structural damage progression on different spinal segments (cervical versus lumbar spine). METHODS: Patients with r-axSpA in the Swiss Clinical Quality Management cohort were included if cervical and lumbar radiographs were available at intervals of 2 years for a maximum of 10 years. Paired radiographs were scored by two calibrated readers according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). The relationship between TNFi use and progression in the cervical and the lumbar spine was analysed using generalised estimating equation models and adjustment for potential confounding. Radiographic progression per spinal segment was defined as an increase of ≥ 1 mSASSS unit or by the formation of ≥ 1 new syndesmophyte over 2 years. RESULTS: Mean ± SD symptom duration was 13.8 ± 9.8 years. Mean ± SD mSASSS progression per radiographic interval was 0.41 ± 1.69 units in the cervical spine and 0.45 ± 1.45 units in the lumbar spine (p = 0.66). Prior use of TNFi significantly reduced the odds of progression in the cervical spine by 68% (OR 0.32, 95% CI 0.14-0.72), but not in the lumbar spine (OR 0.99, 95% CI 0.52-1.88). A more restricted inhibition of progression in the lumbar spine was confirmed after multiple imputation of missing covariate data (OR 0.43, 95% CI 0.24-0.77 and 0.85, 95% CI 0.51-1.41, for the cervical and lumbar spine, respectively). It was also confirmed with progression defined as formation of ≥ 1 syndesmophyte (OR 0.31, 95% CI 0.12-0.80 versus OR 0.56, 95% CI 0.26-1.24 for the cervical and lumbar spine, respectively). CONCLUSION: Disease modification by treatment with TNFi seems to more profoundly affect the cervical spine in this r-axSpA population with longstanding disease. Site-specific analysis of spinal progression might, therefore, improve detection of disease modification in clinical trials in axSpA.

Anaemia may add information to standardised disease activity assessment to predict radiographic damage in rheumatoid arthritis: a prospective cohort study.

OBJECTIVE: Anaemia in rheumatoid arthritis (RA) is prototypical of the chronic disease type and is often neglected in clinical practice. We studied anaemia in relation to disease activity, medications and radiographic progression. METHODS: Data were collected between 1996 and 2007 over a mean follow-up of 2.2 years. Anaemia was defined according to WHO (♀ haemoglobin<12 g/dl, ♂: haemoglobin<13 g/dl), or alternative criteria. Anaemia prevalence was studied in relation to disease parameters and pharmacological therapy. Radiographic progression was analysed in 9731 radiograph sets from 2681 patients in crude longitudinal regression models and after adjusting for potential confounding factors, including the clinical disease activity score with the 28-joint count for tender and swollen joints and erythrocyte sedimentation rate (DAS28ESR) or the clinical disease activity index (cDAI), synthetic antirheumatic drugs and antitumour necrosis factor (TNF) therapy. RESULTS: Anaemia prevalence decreased from more than 24% in years before 2001 to 15% in 2007. Erosions progressed significantly faster in patients with anaemia (p<0.001). Adjusted models showed these effects independently of clinical disease activity and other indicators of disease severity. Radiographic damage progression rates were increasing with severity of anaemia, suggesting a 'dose-response effect'. The effect of anaemia on damage progression was maintained in subgroups of patients treated with TNF blockade or corticosteroids, and without non-selective nonsteroidal anti-inflammatory drugs (NSAIDs). CONCLUSIONS: Anaemia in RA appears to capture disease processes that remain unmeasured by established disease activity measures in patients with or without TNF blockade, and may help to identify patients with more rapid erosive disease.

Measuring finger joint cartilage by ultrasound as a promising alternative to conventional radiograph imaging.

OBJECTIVE: To evaluate the reliability and validity of a novel ultrasound (US) imaging method to measure metacarpophalangeal (MCP) and proximal interphalangeal (PIP) finger joint cartilage. METHODS: We examined 48 patients with rheumatoid arthritis (RA), 18 patients with osteoarthritis (OA), 24 patients with unclassified arthritis of the finger joints, and 34 healthy volunteers. The proximal cartilage layer of MCP and PIP joints for fingers 2-5 was bilaterally visualized from a posterior view, with joints in approximately 90 degrees flexion. Cartilage thickness was measured with integrated tools on static images. External validity was assessed by measuring radiologic joint space width (JSW) and a numeric joint space narrowing (JSN) score in patients with RA. RESULTS: Precise measurement was possible for 97.5% of MCP and 94.2% of PIP joints. Intraclass correlation coefficients for bilateral total joint US scores were 0.844 (95% confidence interval [95% CI] 0.648-0.935) for interobserver comparisons and 0.928 (95% CI 0.826-0.971) for intraobserver comparisons (using different US devices). The US score correlated with JSN for both hands (adjusted R(2) = 0.513, P < 0.001) and JSW of the same finger joints (adjusted R(2) = 0.635, P < 0.001). Reduced cartilage shown by US allowed discrimination of early symptomatic OA versus early RA and healthy joints. In patients with RA, US scores correlated with duration of treatment-resistant, progressive RA. CONCLUSION: The US method of direct visualization and quantification of cartilage in MCP and PIP joints is objective, reliable, valid, and can be useful for diagnostic purposes in patients with arthritis.