Association Between Inflammatory Bowel Disease and Dementia: A Longitudinal Cohort Study

Abstract

Background The association between inflammatory bowel disease (IBD) and dementia remains uncertain. We aim to investigate whether IBD is associated with higher dementia risk. Methods Using multivariable Cox regression models, we analyzed the onset of all-cause dementia among 497,775 participants, including 5778 IBD patients in the UK Biobank as primary analysis. In secondary analysis, we further examined the difference in brain structure and cognitive function changes between IBD and non-IBD individuals. The diagnosis of IBD and dementia was confirmed with combination of primary care data, hospital inpatient data, death registry, and self-report data. Brain structure was measured by brain MRI as anatomic and tissue-specific volumes; cognitive function was tested in terms of reaction, visual episodic memory, verbal-numerical reasoning, and prospective memory. Results During a mean follow-up of 11.58 years, 100 and 6709 incident all-cause dementia with or without IBD were documented, respectively. In multivariable Cox regression model, hazard ratio for incident dementia among IBD patients was 1.14 (95% confidence interval [CI], 0.94-1.39; P=.182) comparing with non-IBD participants; no statistically significant difference was observed in their brain MRI measures of anatomic and tissue-specific volumes, whereas IBD patients had a significantly increased reaction time (β=12.32; 95% CI, 1.97, 22.67; P = .020). Results of subgroup and sensitivity analyses were consistent with the main analysis. Conclusions Our study does not support a significant association between IBD and dementia. Further studies with better design and longer follow-up are needed to elucidate the association.

Risk of dementia in patients with inflammatory bowel disease: a Danish population‐based study

“…22,23 Contrasting these studies, a Swiss cross-sectional study found an approximately 20% lower dementia prevalence in IBD patients, estimated, however, with low statistical precision. 24 Finally, two recent studies from the United Kingdom 26 and Canada 25 found no overall association between IBD and dementia. The Canadian study had over 30 years of follow-up 25 .…”

“…However, the results of studies investigating the association between IBD and dementia are conflicting. [22][23][24][25][26] A Taiwanese population-based cohort study showed a 2.5-fold increased risk of dementia in IBD patients, 22 whereas a German study of IBD patients followed in general practices found an only 1.2-fold increase. 23 Both studies had limited follow-up time and restricted age groups of IBD patients.…”

“…None of the abovementioned studies investigated the risk of dementia subtypes other than Alzheimer's disease (AD) and vascular dementia (VaD). [22][23][24][25][26] An association between IBD and dementia could prove important for early detection and intervention against dementia in IBD patients 27 and foster new understanding of the long-term effects of intestinal inflammation. With access to wide longitudinal data from Danish healthcare registries, we therefore performed a nationwide population-based cohort study to investigate risk of all-cause dementia in patients with IBD (UC or CD).…”

Editorial: IBD and the risk of dementia ‐ the jury is still out

“…Nevertheless, this systematic review did not include results from the United Kingdom cohort 6 where there was no significant association reported between IBD and dementia. Notably, studies from Germany 7 and Taiwan 8 found that the risk of dementia was higher in IBD patients than in the non-IBD population (HR 1.22, 95% CI 1.07-1.39 and HR 2.54, 95% CI 1.91-3.37, respectively).…”

“…The present findings mirror the results of a systematic review by Liu et al 5 which concluded that a diagnosis of IBD confers an increased risk of dementia (HR = 1.27, 95% CI 1.10–1.47). Nevertheless, this systematic review did not include results from the United Kingdom cohort 6 where there was no significant association reported between IBD and dementia. Notably, studies from Germany 7 and Taiwan 8 found that the risk of dementia was higher in IBD patients than in the non‐IBD population (HR 1.22, 95% CI 1.07–1.39 and HR 2.54, 95% CI 1.91–3.37, respectively).…”