Influence of Age and Sex on Disease Course and Treatment in Rheumatoid Arthritis.

Objective: More than 50% of patients with rheumatoid arthritis (RA) are >65 years at diagnosis. Age of onset and sex may influence the disease course, outcome and treatment. This study follows a large cohort of patients with early RA to assess contributions of age and sex to disease outcomes.

Methods: Patients from the BARFOT cohort, n=2837 (68% women), were followed for eight years at predefined time points to assess inflammation, function, joint destruction and treatment with disease modifying anti-rheumatic drugs (DMARDs) and glucocorticoids (GC). The patients were divided by sex and age at inclusion (<40, 40-54, 55-69 and ≥70 years).

Results: For both sexes, disease activity, function and pain improved over time, significantly more in men than in women in all age groups. In men, those <40 years displayed significantly lower DAS28 compared with all other groups. This group was also the least represented group in the study. The Sharp van der Heijde Score (SHS) increased over time in both sexes and all age groups. Women ≥70 years showed less improvement in disability and the highest progression of SHS mainly due to increased joint space narrowing. Patients <40 years were more likely to receive biological DMARDs, while those ≥70 years more often received only GC treatment.

Conclusion: There were significant age- and sex-dependent differences in the medical treatment and in outcome of RA 8 years after diagnosis. The differences were most pronounced in men<40 and women ≥70 years, but whether they are due to disease phenotype or treatment is unclear.