Rheumatoid arthritis and the risk of dementia: A systematic review and meta-analysis

Background: The association between chronic inflammation and dementia has been identified in several epidemiologic studies. However, the data on rheumatoid arthritis (RA), one of the most common chronic inflammatory disorders, remains unclear. Materials and Methods: We conducted a systematic review and meta-analysis of cohort, case-control, and cross-sectional studies that compared the risk of dementia in patients with RA versus non-RA controls. Data from each study were combined using random-effect, generic inverse variance method of DerSimonian and Laird to calculate the pooled risk ratio (RR) and 95% confidence interval (C). Results: Three cohort studies and two cross-sectional studies were identified and included in the meta-analysis. We found a significantly increased risk of dementia among patients with RA, with the pooled risk ratio of 1.61 (95% Cl, 1.10-2.37). The statistical heterogeneity was high, with an 12 of 91%. Conclusions: Our study demonstrated a statistically significant increase in the risk of dementia among patients with RA.