IBD & risk of dementia

IBD & risk of dementia

January 12, 2021

Issue 01

Clinical Question

Are IBD patients at increased risk of dementia?

Editor’s Bottom Line

IBD appears to be associated with an increased risk of dementia. Mechanisms that might explain this association need to be explored.


Zhang B, Wang HE, Bai Y-M, et al. Inflammatory bowel disease is associated with higher dementia risk: a nationwide longitudinal study. Gut. 2021;70:85–91; http://dx.doi.org/10.1136/gutjnl-2020-320789


Prior research has found a link between inflammatory bowel disease (IBD) and Parkinson’s disease, and other literature has pointed to chronic systemic inflammation as a cause of neurological changes including Alzheimer’s disease. Adding to this evidence, researchers in the United States and Taiwan compared dementia rates among 1,742 patients with IBD and 17,420 controls included in the Taiwan National Health Insurance Research Database. Subjects were at least 45 years of age at study outset and were followed for up to 16 years.

Findings showed that 5.5% of IBD patients and 1.4% of controls were diagnosed with dementia during the study period (p<0.001). Multivariate analysis confirmed a 2.5-fold increased risk of dementia diagnosis among IBD patients, compared to controls (Hazard Ratio: 2.54; 95% Confidence Interval, 1.91–3.37).

More specifically, 1.9% and 0.2% of IBD patients and controls, respectively, were diagnosed with Alzheimer’s disease, while 0.7% and 0.2%, respectively, were diagnosed with vascular dementia and 2.9% and 1.9%, respectively, were diagnosed with an unspecified dementia during the study. IBD patients were an average 76 years of age at the time of dementia diagnosis, compared to 83 years of age among controls. The risk of dementia did not differ by sex or IBD phenotype.


Study Design: Population-based cohort
Funding: The Taipei Veterans General Hospital, Yen Tjing Ling Medical Foundation, Ministry of Science and Technology, Taiwan, and the United States National Institutes of Health.
Allocation: Not applicable
Setting: Multicenter
Level of Evidence: 2b