Do Smoking and Socioeconomic Factors Influence Imaging Outcomes in Axial Spondyloarthritis? Five‐Year Data From the DESIR Cohort

Abstract

Objective To investigate the relationship between smoking and imaging outcomes over 5 years in axial spondyloarthritis (SpA) and to assess whether socioeconomic factors influence these relationships. Methods Axial SpA patients from the Devenir des Spondylarthropathies Indifferérenciées Récentes cohort were included. The following 4 imaging outcomes were assessed by 3 central readers at baseline, 2 years, and 5 years: spine radiographs (using the modified Stoke Ankylosing Spondylitis Spine Score [mSASSS]), sacroiliac (SI) joint radiographs (using the modified New York criteria), magnetic resonance imaging (MRI) of the spine (using the Spondyloarthritis Research Consortium of Canada [SPARCC] score), and MRI of the SI joint (using the SPARCC score). The explanatory variable of interest was smoking status at baseline. Interactions between smoking and socioeconomic factors (i.e., job type [blue‐collar or manual work versus white‐collar or nonmanual work] and education [low versus high]) were first tested, and if significant, analyses were run using separate strata. Generalized estimating equations models were used, with adjustments for confounders. Results In total, 406 axial SpA patients were included (52% male, 40% smokers, and 18% blue collar). Smoking was independently associated with more MRI‐detected SI joint inflammation at each visit over the 5 years, an effect that was seen only in patients with blue‐collar professions (β = 5.41 [95% confidence interval (95% CI) 1.35, 9.48]) and in patients with low education levels (β = 2.65 [95% CI 0.42,4.88]), using separate models. Smoking was also significantly associated with spinal inflammation (β = 1.69 [95% CI 0.45, 2.93]) and SI joint damage (β = 0.57 [95% CI 0.18, 0.96]) across all patients, irrespective of socioeconomic factors and other potential confounders. Conclusion Strong associations were found between smoking at baseline and MRI‐detected SI joint inflammation at each visit over a time period of 5 years in axial SpA patients with a blue‐collar job or low education level. These findings suggest a possible role for mechanical stress amplifying the effect of smoking on axial inflammation in axial SpA.

2021 EULAR recommendations regarding lifestyle behaviours and work participation to prevent progression of rheumatic and musculoskeletal diseases

“…There have been several studies about work participation in people with RMDs, including studies of interventions aiming to keep people in work 102. While there are some inconsistencies between these studies, perhaps due to power and different outcome assessments, many indicated that work was probably not detrimental (although there is evidence that physically demanding jobs are associated with increased radiographic progression in axSpA103 104) and in some cases beneficial for people with RMDs in terms of RMD outcomes 105–107. Given this, and the benefits of work on quality of life seen in the general population,108 work should receive increased attention in healthcare consultations with people with RMDs, and specialised health professionals should be involved.…”

Sick leave in early axial spondyloarthritis: the role of clinical and socioeconomic factors. Five-year data from the DESIR cohort

“…In line with this observation, in previous analyses in DESIR we have seen smoking to be associated with MRI-SIJ inflammation specifically in patients with bluecollar jobs or low education. 26 The retention of smoking in the models may have contributed for clinical variables like function and spinal mobility, not having an independent significant effect in the multivariable models, corrected for the above-mentioned socioeconomic factors, while they were significant in univariable analyses. Disentangling individual effects especially when it comes to complex relationships between disease, context and outcome can thus be challenging partly due to residual confounding which cannot always be controlled.…”

“…17 In our study, education and in particular, lower education was associated with a higher hazard of SL. This observation could be explained by residual confounding, whereby people with lower education are more likely to take manual jobs, 26 which have further been shown to associate with poorer work outcome. Of note, a crosssectional multicentre study showed that mastery, an important personal factor linked to self-efficacy, was associated with being employed in patients, but only in those with low education.…”

“…The latter differs from the findings of other studies, a likely explanation for this difference being the fact that our study was based in early axSpA with little amount of damage accrued over time, as we have previously shown. 26 Furthermore, our study specifically aimed to address the impact of both socioeconomic and clinical factors on SL, recognising the potential relevance of socioeconomic factors alongside clinical factors, on this work outcome. This was reflected in our modelling approach, which placed the emphasis on both contextual and clinical factors on building the models.…”

Factors associated with remission at 5-year follow-up in recent-onset axial spondyloarthritis: results from the DESIR cohort

“…In previous studies, when measured with the ASDAS-CRP, disease activity did not differ between men and women [ 40 , 41 ]. Furthermore, although a link between smoking, inflammation and structural damage in early stages of axSpA has been suggested [ 21 , 42 ], the effect of smoking on long-term remission is not clear, and several studies have failed to find this association for all patients (association only in men and blue-collar patients) [ 43 , 44 ].…”