Revisiting the Association Between Inflammatory Bowel Disease and Parkinson's Disease

Background: Several studies have reported an association between inflammatory bowel disease (IBD) and Parkinson's disease (PD). The aim of this study is to re-evaluate for an association between IBD and PD while controlling for potential socioeconomic and environmental confounders. Methods: We performed a retrospective cohort study using the Truven Health Marketscan database between January 1, 2005, and December 31, 2014. Individuals with IBD and household age-matched controls were identified. Adjusted hazard ratios (HRs) were calculated for the development of incident PD, adjusting for age, sex, residence type, US region, comorbidities, and behavior. Results: In all, 154 051 subjects with IBD and an equal number of controls were identified. During a mean (SD) follow-up of 3.8 (2.2) years, 132 incident PD cases were identified. There was no significant association between IBD and PD (adjusted HR, 1.01; 0.72-1.42) when adjusting for the confounders previously mentioned. Conclusions: We found no statistically significant association between these disorders. It is possible that previous associations identified between these disorders were confounded by environmental and socioeconomic factors.