Background Rheumatoid arthritis (RA) is a chronic disease characterized by a peak incidence in the fourth and fifth decades of age. Despite several cross-sectional and a few prospective studies, it has not been clearly established whether there are important clinical differences between early-onset and late-onset RA.
Objectives To investigate whether age at disease onset determines clinical, radiographic or functional outcomes in a cohort of early RA.
Methods The ESPOIR cohort is a longitudinal, prospective, multicenter, observational study that included adult patients with early arthritis. Patients fulfilling the 2010 ACR/EULAR criteria for RA over the first 3 years of follow-up were selected for the present study (n=698). Patients were pooled into 3 groups according to their age at RA onset: <45 years (early-onset [EORA], n=266), 45 to 60 years (intermediate-onset [IORA], n=314) and >60 years (late-onset [LORA], n=118). The following outcomes were compared at baseline and over the first 3 years of follow-up according to the age at disease onset: SDAI remission rate, total Sharp score and HAQ-DI score.
Results The main baseline characteristics of RA patients were as follows: median (IQR) age = 50.3 (39.8-57.2) years, female = 78.2%, median (IQR) SDAI = 28.5 (20.6-38.6), median (IQR) HAQ-DI score = 1 (0.5-1.5), RF+ = 53%, ACPA+ = 45%. Outcomes of interest are shown at baseline and over the first 3 years of follow-up according to the age at disease onset (Table).
Conclusions In a cohort of early RA patients, a younger age at disease onset is associated with a higher rate of remission at 1 year, a lower radiographic score at baseline and thereafter over the 3-year follow-up period and a lower functional score at 1 year and thereafter over the 3-year follow-up period. The analysis of the potential impact of treatment modalities on these age-related differences is under process.
Disclosure of Interest None Declared