Peter I, et al. - Experts compared the incidence of Parkinson's disease (PD) among individuals with or without inflammatory bowel disease (IBD). Additionally, they gauged whether PD risk among patients with IBD was altered by anti–tumor necrosis factor (anti-TNF) therapy. There was a higher incidence of PD among patients with IBD than those without IBD. Early exposure to anti-inflammatory anti-TNF therapy was linked to a markedly reduced PD incidence, so systemic inflammation may play a role in the pathogenesis of both diseases.

Methods

• Using Truven Health MarketScan administrative claims database and the Medicare Supplemental Database, a retrospective cohort study was performed between January 1, 2000, and March 31, 2016.
• Inclusion criteria was at least 2 claims for IBD diagnoses, at least 6 months of follow-up, and no prior diagnosis of PD on or before the IBD index date.
• Exposure to anti-TNF therapy was described as the anti-TNF index date to the last date of anti-TNF coverage or the end of enrollment or PD index date, whichever was earliest.
• For this study, the incidence rates per 1,000 person-years were computed, and crude and adjusted incidence rate ratios were estimated by Poisson regression models and presented with 95% CIs.
• Incidence of PD among patients with IBD with or without exposure to anti-TNF therapy served as the primary outcome.

Results

• Researchers matched 144,018 individuals with IBD on age, sex, and year of index date with 720,090 unaffected controls.
• It was reported that 1,796 individuals had at least 2 PD diagnoses and at least 1 filled PD-related prescription.
• The mean (SD) age of individuals with IBD was 51 (17) years and 44% were men.
• Incidence of PD among patients with IBD was 28% higher than that of unaffected matched controls (adjusted incidence rate ratio, 1.28; 95% CI, 1.14-1.44; P < .001).
• There was a 78% reduction in the incidence rate of PD among patients with IBD who were exposed to anti-TNF therapy vs those who were not exposed (adjusted incidence rate ratio, 0.22; 95% CI, 0.05-0.88; P=.03).