POS0438 IS IMAGING DETECTED JOINT INFLAMMATION HELPFUL IN EXPLAINING FATIGUE IN RHEUMATOID ARTHRITIS AT DIAGNOSIS AND DURING THE DISEASE COURSE? – A LARGE MRI STUDY

Abstract

Background:Fatigue in rheumatoid arthritis (RA) is hypothesized to be caused by inflammation. Still ~50% of fatigue in RA cannot be explained by the disease activity score (DAS), nor by generic or psychological factors.Objectives:Since MRI can detect joint inflammation more sensitively than DAS, we hypothesized that residual inflammation detected by MRI could aid in explaining fatigue in RA at diagnosis and during follow-up.Methods:526 consecutive RA-patients were followed longitudinally. Fatigue was assessed yearly on a numerical rating scale. Hand and foot MRIs were performed at inclusion, after 12 and 24-months in 199 patients and were scored for inflammation (synovitis, tenosynovitis and osteitis combined). We studied whether RA-patients with more MRI-inflammation were more fatigued at diagnosis (linear regression), whether the 2-year course of MRI-inflammation associated with the course of fatigue (linear mixed models) and whether decrease in MRI-inflammation in year-1 associated with subsequent improvement in fatigue in year-2 (cross-lagged models). Similar analyses were done with DAS as inflammation measure.Results:At diagnosis, higher DAS-scores were associated with more severe fatigue (p<0.001). However, patients with more MRI-inflammation were not more fatigued (p=0.94). During 2-year follow-up, DAS decrease associated with improvement in fatigue (p<0.001), but MRI-inflammation decrease did not (p=0.96). DAS decrease in year-1 associated with fatigue improvement in year-2 (p=0.012), as did MRI-inflammation decrease (p=0.039), with similar effect strength.Conclusion:Sensitive measurements of joint inflammation did not aid in explaining fatigue in RA at diagnosis and follow-up. This supports the concept that fatigue in RA is partly uncoupled from inflammation.Disclosure of Interests:None declared