The association between systemic lupus erythematosus and dementia: A meta-analysis

A growing body of evidence indicates that systemic lupus erythematosus (SLE) is associated with increased risk of cognitive impairment and dementia. However, to date, no studies have been conducted to quantitatively summarize and evaluate the consistency of data. Objective: To quantitatively evaluate the relationship of SLE and antiphospholipid antibodies (aPL) with cognitive dysfunction and dementia. Methods: All relevant literature was retrieved from Pubmed, Scopus, and PsycINFO databases. The meta-analysis was performed using effect estimates and 95% confidence intervals (CIs) to calculate pooled risk estimates. The heterogeneity among studies was also examined. Results: The meta-analysis included 11 original studies involving a total of 81,668 patients with dementia and 407 patients with cognitive dysfunction. There were significant associations on fixed-effect models between SLE and dementia (3 studies; RR=1.50; 95% CI=1.37-1.64), SLE and cognitive dysfunction (4 studies; OR=2.97; 95% CI=1.72-5.15), and aPL and cognitive dysfunction (5 studies, OR=1.97; 95% CI=1.55-2.52). We also combined cognitive dysfunction and dementia outcomes as they both represented cognitive impairment. There were significant associations between aPL and cognitive impairment (6 studies; OR=2.03; 95% CI=1.62-2.55), and SLE and cognitive impairment (7 studies; OR=1.83; 95% CI=1.42–2.35). Moderate heterogeneity (I² =45.7%) was found in the association between SLE and cognitive impairment, low heterogeneity (I² =21.8%) in the association between SLE and dementia, and near zero heterogeneity for the other three main analyses. Conclusion: Both SLE and aPL are associated with cognitive impairment.