POS0938 PROLONGED PHYSICAL STRAIN AT WORK CONFERS RISK FOR DEVELOPMENT OF RHEUMATOID ARTHRITIS IN PATIENTS WITH CLINICALLY SUSPECT ARTHRALGIA: CUES FOR MECHANICAL FACTORS AS FINAL PATHOPHYSIOLOGICAL HIT

Background Some case-control studies have identified physical workload as a risk-factor for rheumatoid arthritis (RA). Objectives To better understand its influence on the pathophysiological trajectory of RA-development, we studied relation work-related strain with MRI-detected joint-inflammation in clinically suspect arthralgia (CSA) and general population, progression from CSA to clinical arthritis. Methods 501 consecutively presenting CSA-patients 155 symptom-free persons filled out questionnaires their occupation. Physical was determined using International Standard Classification Occupations (ISCO) per subject-reported Contrast-enhanced hand-MRIs were evaluated synovitis/tenosynovitis/osteitis (summed joint-inflammation) RAMRIS-method. followed development (median follow-up 25 months). Analyses included interaction age proxy prolonged strain. Results In CSA-patients, degree associated severity subclinical joint-inflammation, independent BMI/smoking/education-level: there positive between strain; p=0.007. Plotting age-dependent effects showed aged ≥50 years (Figure 1A), suggesting effect relates Especially tenosynovitis increased higher Prolonged not joint-inflammation. Older (≥ 50 years) developed more often 1B; HR 1.17 (95%CI 1.00–1.35) 10 percentage-points increase; p=0.043). This partially mediated by Moreover, known association low educational attainment development. Conclusion increases risk developing RA which is an points mechanical factors final hit pathophysiology RA-development. Figure 1. Acknowledgements We thank dr. B. Ravesteijn sharing occupation-specific data (see et al., Health Econ. 2018, www.bastianravesteijn.com ). Disclosure Interests None Declared.