Association of Parkinson’s disease and treatment with aminosalicylates in inflammatory bowel disease: a cross-sectional study in a Spain drug dispensation records

Objectives To analyse the association between aminosalicylate-treated inflammatory bowel disease (IBD) and Parkinson’s disease (PD) at population level. Design Cross-sectional study. Setting The study was performed based on electronic drug prescription and dispensation records of the Andalusian Public Health System. Participants All individuals aged ≥50 years with at least one drug dispensation during December 2014 were identified from the records. Primary and secondary outcome measures Groups were formed: ‘possible PD’ group, including all who received an anti-Parkinson agent; ‘possible IBD’ group, those treated with mesalazine and/or derivatives (5-aminosalicylic acid (5-ASA)); and ‘possible PD and IBD’, including those receiving both anti-Parkinson agent and 5-ASA. Prevalence of possible PD was determined among those with possible IBD and among those without this condition. The age-adjusted and sex-adjusted OR was calculated. Results We recorded 2 020 868 individuals (68±11 years, 56% female), 19 966 were included in possible PD group (75±9 years, 53% female) and 7485 in possible IBD group (64±10 years, 47% female); only 56 were included in both groups (76±8 years, 32% female). The prevalence of possible PD was 0.7% among those with possible IBD and 1% among those without this condition (adjusted OR=0.94; 95% CI 0.72 to 1.23; p=0.657). OR was 0.28 in individuals aged ≤65 years (95% CI 0.10 to 0.74; p=0.01) and 1.17 in older individuals (95% CI 0.89 to 1.54; p=0.257). Conclusions Within the limitations of this study, the results suggest a protective role for IBD and/or 5-ASA against PD development, especially among under 65-year olds. Further studies are warranted to explore this association given its scientific and therapeutic implications.