Study Suggests Risk of Cognitive Decline, Dementia Is Not Impacted by RA Status

Risk of cognitive decline and dementia are similar between patients with and without rheumatoid arthritis (RA), according to results from the Mayo Clinic Study of Aging (MCSA) and published in Journal of Alzheimer’s Disease.

This contradicts past observational studies that have suggested dementia risk is higher for patients with RA compared with the general population.

This study found that risk for incident dementia was similar between patients in the 2 groups matched by age, sex, education level, and baseline cognitive diagnosis. However, patients with RA were found to have more abnormal cerebrovascular pathology on neuroimaging compared with patients without RA.

The authors of the MCSA matched 104 adult patients with RA 1:3 with 312 patients without RA. The mean (SD) age was 75 (10.4) years, with 33% of participants being male and an average follow-up of 4.2 (3.8) years.

Among the 104 participants with RA, 80 had not experienced cognitive impairment, 21 had experienced mild cognitive impairment, and 3 had dementia at baseline.

They also assessed neuroimaging biomarkers of aging, Alzheimer’s disease, and vascular pathology. Participants with available neuroimaging included 33 with RA and 98 without, and these participants were also matched.

These patients had similar amyloid burden and neurodegeneration measures, including regions sensitive to aging and dementia.

However, patients with available imaging and with RA had a greater mean (SD) white matter hyperintensity (WMH) volume of 1.12% (0.57%) relative to the total intracranial volume, compared with patients without RA who had a WMH volume of 0.76% (0.69%).

Patients with RA also had a higher mean number of cortical infarctions at 0.24 (0.44) compared with patients without RA, with 0.05 (0.33).

These associations remained when comparisons were made only between patients who have not experienced any cognitive impairment, and when patients with diabetes—a potential risk factor for WMH—were excluded.

Patients with RA receiving biologic disease-modifying antirheumatic drugs (bDMARDs) including TNF inhibitors did not experience cognitive decline during follow-up. According to the authors, this is “an important observation regarding cognitive changes in the chronic inflammatory setting of RA and the use of bDMARDs.”

However, due to the small sample size, interpretations must be made with caution and further research is necessary.

“Future studies should examine the mechanisms underlying these changes and potential implications for prognostication and prevention of cognitive decline in RA,” the authors added.

Reference

Vassilaki M, Crowson CS, Davis III JM, et al. Rheumatoid arthritis, cognitive impairment, and neuroimaging biomarkers: results from the mayo clinic study of aging. J Alzheimers Dis. Published online August 9, 2022. doi:10.3233/JAD-220368