Inflammatory bowel disease may play a role in neurodegeneration

Patients with inflammatory bowel disease (IBD) have more than a twofold risk of developing dementia, according to a study, implicating gut–brain axis and chronic inflammation in progressive neurocognitive degeneration.

Researchers looked at 1,742 IBD patients aged ≥45 years old and matched 17,420 controls from the Taiwanese National Health Insurance Research Database. All individuals were followed for dementia diagnosis for up to 16 years.

Significantly more IBD patients than controls developed dementia during the follow-up period (5.5 percent vs 1.4 percent; p<0.001). This increased incidence was observed across dementia types: Alzheimer’s disease (1.9 percent vs 0.2 percent; p<0.001), vascular dementia (0.7 percent vs 0.2 percent; p=0.001), and unspecified dementia (2.9 percent vs 1.9 percent; p<0.001).

Notably, dementia occurred more than 7 years earlier in the IBD group than in the control group. The average age at diagnosis was 76.24 vs 83.45 years.

In a multivariable Cox regression model, IBD conferred a twofold increased risk of incident dementia (hazard ratio [HR], 2.54, 95 percent confidence interval [CI], 1.91–3.37). The risk increase was most pronounced for Alzheimer’s disease (HR, 6.19, 95 percent CI, 3.31–11.57), followed by unspecified (HR, 2.88, 95 percent CI, 2.11–3.93) and vascular dementia (HR, 2.60, 95 percent CI, 1.18–5.70).

The risk did not significantly differ between male and female IBD patients and between ulcerative colitis and Crohn’s disease.

Additional research is needed to elucidate the relationship between IBD and dementia. Physicians should be aware and vigilant regarding the increased dementia risk among elderly IBD patients, as this may facilitate early intervention, which in turn may slow cognitive decline and improve quality of life, according to the researchers.