To investigate the association between disease activity and cognitive impairment in patients with rheumatoid arthritis (RA).
A total of 464 patients from the rheumatoid arthritis registry of two academic centers, Siriraj and Phramongkutklao hospitals, were included. Demographic, clinical, and laboratory data related to disease activity and functional status were collected. Cognitive function was assessed using the Thai version of the Montreal Cognitive Assessment (MoCA-T). Subjects were classified as cognitively impaired if they scored less than 25.
Most subjects (85%) were female with a mean age ± SD of 59.2 ± 11.4 years old and a median (range) educational level of 9 (4-14) years. They were long-standing RA patients (median disease duration (range) of 9.9 (5.1-16.6) years) and had moderate cumulative disease activity (mean DAS28 ± SD of 3.5 ± 0.81) and mild functional impairment (median HAQ (range) 0.5 (0.13-1.10)). Seventy percent of the patients were classified as having cognitive impairment. The patients with cognitive impairment significantly impaired in all domains, especially in visuospatial/executive, language, and abstraction. In multiple logistic regression analyses, old age (RR 3.45, 95% CI 2-6, p < 0.001), low education (RR 10.8, 95% CI 5.3-22.1, p < 0.001), and high cumulative disease activity (RR 2.2, 95% CI 1.07-4.7, p = 0.033) were independently associated with cognitive impairment.
High cumulative RA disease activity is associated with cognitive impairment. Therefore, treat-to-target aimed at low disease activity or remission may be beneficial for preventing cognitive decline in RA patients.