The Impact of Exercise, Lifestyle, and Clinical Factors on Perceived Cognitive Function in Patients with Rheumatoid Arthritis: Results from a Prospective Cohort Study

Objective: Lifestyle factors, such as inactivity and obesity, contribute to cognitive decline in the general population, but little is known about how these factors may affect individuals with a chronic inflammatory condition such as rheumatoid arthritis (RA). We studied the clinical and functional risk factors related to a worsening of perceived cognitive function in patients with RA.

Methods: We collected clinical and functional questionnaire data over 10 years in a prospective RA cohort including yearly self-reported memory, concentration, and word-finding difficulties graded from "never" to "often." Generalized estimating equation models examined the role of exercise (defined as those meeting the Department of Health and Human Services physical activity guidelines of 75 minutes of vigorous or 150 minutes of moderate aerobic activity per week), body mass index (BMI), sleep, depression (Mental Health Index-Depression), Disease Activity Score (DAS)28-c-reactive protein (CRP)3 score, disease-modifying antirheumatic drug, and corticosteroid use from the previous year as predictors of cognitive complaints that progressed to "often" compared with the previous year (the first year (T _i ) progressed to "often" 1 year later (T _i+1)).

Results: Of 1219 RA subjects, 127 (10.4%) described either poor memory, concentration, or word-finding difficulties as affecting them "often" at study entry. RA patients (n = 1092, mean age = 56.5 years, 82% female, 58% college educated) were less likely to report word-finding difficulties, poor memory, and concentration as "often" if they were physically active (p = 0.0001, P = 0.01, P < 0.0001, respectively). Female RA patients developed more concentration complaints compared with males (P = 0.03); patients taking an anti-tumor necrosis factor therapy were less likely to complain of poor memory (P = 0.01). Sleep, BMI, fatigue, depression, DAS28-CRP3, methotrexate, and corticosteroid use were not independently associated with a worsening of any cognitive complaints.

Conclusion: RA patients who are physically active are less likely to report cognitive difficulties. Our study suggests potential modifiable risk factors for the prevention of cognitive dysfunction in RA.