Objective Increasing evidence supports reciprocal communication between the enteric and the central nervous system in disease, termed the ‘gut–brain axis’. Recent findings suggest a connection between IBD and development of Parkinson’s disease. The role of IBD in dementia, another insidious neurodegenerative disorder, has not been explored. Design Using the Taiwanese National Health Insurance Research Database, we performed comparative analysis of 1742 patients with IBD ≥45 years old against 17 420 controls to assess dementia risk following IBD diagnosis. Controls were matched on bases of sex, access to healthcare, income and dementia-related comorbidities. All individuals were followed for dementia diagnosis for up to 16 years. Subanalyses included the relationship between sex, ulcerative colitis (UC) and Crohn’s disease (CD), and dementia risk. Results Overall incidence of dementia among patients with IBD was significantly elevated (5.5% vs 1.4% among controls). Patients with IBD were diagnosed with dementia at 76.24 years old on average, compared with 83.45 among controls. The HR of developing dementia among patients with IBD was 2.54 (95% CI 1.91 to 3.37). Among dementia types, the risk of developing Alzheimer’s dementia demonstrated the greatest increase. Dementia risk did not differ between sex differences nor UC versus CD. Conclusion This population-based cohort study demonstrates significant association between IBD and subsequent development of dementia. Dementia was diagnosed at an earlier age among patients with IBD, and disease risk appeared to increase with IBD chronicity. These findings highlight the need for future research to elucidate the relationship between IBD and dementia.

OBJECTIVE: Studies have suggested the association between autism spectrum disorder (ASD) and type 2 diabetes mellitus (DM)–related risk factors, such as obesity and dyslipidemia. However, the association between ASD and type 2 DM remains unknown. RESEARCH DESIGN AND METHODS: We used the Taiwan National Health Insurance Research Database for enrolling 6,122 adolescents and young adults with ASD and 24,488 age- and sex-matched control subjects between 2002 and 2009 and monitored them until the end of 2011. Participants who developed type 2 DM during the follow-up period were identified. RESULTS: Adolescents (hazard ratio [HR] 2.71 [95% CI 1.64–4.48]) and young adults (HR 5.31 [95% CI 2.85–9.90]) with ASD had a higher risk of developing type 2 DM than those without ASD, after adjustment for demographic data, atypical antipsychotics use, and medical comorbidities. Sensitivity analyses after excluding first year (HR 3.03 [95% CI 2.03–4.51]) and first 3-year (HR 2.62 [95% CI 1.62–4.23]) observation periods were consistent. Short-term (HR 1.97 [95% CI 1.20–3.23]) and long-term (HR 1.64 [95% CI 1.02–2.63]) use of atypical antipsychotics were associated with a higher likelihood of subsequent type 2 DM. CONCLUSIONS: Adolescents and young adults with ASD were more likely to develop type 2 DM during the follow-up. In addition, those with ASD using atypical antipsychotics exhibited a high risk. Therefore, further research is necessary to investigate the common pathophysiology of ASD and type 2 DM.