Age of onset of rheumatoid arthritis and radiographic changes

The association between age of rheumatoid arthritis (RA) onset and joint erosions remains unclear. We investigated the effects of age of RA onset on incident joint erosion and the progression of radiographic findings.

Patients diagnosed with RA within 2 years of enrollment in a large single-center RA registry were included. The age of RA onset was categorized into young- (≤44 years of age), middle- (45-65), and late-onset (≥66). Modified total Sharp scores (mTSS) were obtained at baseline, year 2, and year 5, and incident joint erosion was defined as an erosion score >0. Adjusted odds ratio (aOR) of incident joint erosions and adjusted change in mTSS by age category were evaluated over a 5-year follow-up period.

Among 1,581 participants with RA, 284 patients within 2 years of RA diagnosis were identified. The mean mTSS were 0.54 in the young-, 3.12 in the middle-, and 4.77 in the late-onset group. The aOR of incident joint erosion in the middle-, aOR 4.0 (95 % CI 2.2 - 7.5), and the late-onset groups, 8.2 (95 % CI 3.6 - 19.2), were elevated compared with the young-onset group. Compared with the young-onset group, the adjusted changes in mTSS in the middle- group, 2.8 (95 % CI 0.20 - 5.4), and the late-onset groups, 1.9 (95 % CI -0.26 - 4.1), were elevated.

The odds of incident joint erosion and change in the mTSS were increased among patients with later RA onset. Age of RA onset should be considered when determining optimal management strategies.