To explore the prevalence and possible predictors of cognitive impairment in persons with rheumatoid arthritis (RA).
Individuals from a longitudinal cohort study of RA participated in a study visit that included a range of physical, psychosocial, and biologic metrics. Cognitive function was assessed using a battery of 12 standardized neuropsychological measures yielding 16 indices. Subjects were classified as "impaired" if they performed 1 SD below age-based population norms on at least 4 of 16 indices. Logistic regression analyses were conducted to identify which of the following were significant predictors of cognitive impairment: sex, race, income, education, depression, disease duration, disease severity, C-reactive protein (CRP) level, glucocorticoid use, and cardiovascular disease (CVD) risk factors.
A total of 115 subjects with a mean ± SD age of 58.6 ± 10.8 years were included; 64% were women and 81% were white. The proportion of persons who were classified as cognitively impaired was 31%. Education, income, glucocorticoid use, and CVD risk factors independently predicted cognitive impairment, controlling for sex, race, disease duration, disease severity, CRP level, and depression. Individuals with cognitive impairment were more likely to have low education (odds ratio [OR] 6.18, 95% confidence interval [95% CI] 1.6-23.87), have low income (OR 7.12, 95% CI 1.35-37.51), use oral glucocorticoids (OR 2.92, 95% CI 1.05-8.12), and have increased CVD risk factors (OR 1.61, 95% CI 1.19-2.17 per risk factor).
The findings of this study suggest that the burden of cognitive impairment in RA is significant, and future studies identifying specific etiologic contributors to cognitive impairment are warranted.