Autoimmune Diseases May Increase the Risk of Dementia

Individuals with autoimmune diseases may have an increased risk of developing dementia.

In a study published in the Journal of Epidemiology & Community Health, investigators found that autoimmune diseases, including multiple sclerosis (MS), lupus, and psoriasis, showed a statistically significant association with dementia.

However, the authors stressed that the study did not prove that autoimmune disease causes dementia, but merely showed the conditions are associated with a higher risk.

“How do [autoimmune diseases] affect the brain? We don’t know, although others have suggested that chronic inflammation, possibly autoimmune effects, or possibly both, may have a role in Alzheimer’s,” said study co-author Dr Michael Goldacre.

For the study, investigators examined data from more than 1.8 million individuals in England who had been admitted to a hospital with an autoimmune disease between 1998 and 2012.

Patients admitted for treatment of an autoimmune disorder were 20% more likely to be admitted to the hospital in the future with dementia compared with individuals admitted for other causes.

When the findings were broken down by type of dementia, the results showed that autoimmune disease only increased the risk of Alzheimer’s disease by approximately 6%. Instead, they appeared to have a much stronger impact on the risk of vascular dementia.

The risk of vascular dementia was 28% higher in individuals with autoimmune diseases, according to the study.

When the diseases were broken out, the investigators found that individuals with MS had nearly double the risk of dementia. Psoriasis was associated with a 29% increased risk; lupus showed a 46% increased risk; rheumatoid arthritis showed a 13% increased risk; and Crohn’s disease showed a 10% increased risk.

The increased risk for vascular dementia may be caused by the effect autoimmune diseases have on the circulatory system, according to the study.

The authors noted that the study is observational and does not prove a direct cause and effect link. Furthermore, the associations found were small.

For further coverage from the fields of Alzheimer’s disease and dementia, check out Specialty Pharmacy Times' sister site, NeurologyLive. The site's condition-specific page serves as a resource for the latest clinical news, articles, videos, and the most recently released data.