Environmental Exposure to Trace Elements and Heavy Metals Preceding the Clinical Onset of Inflammatory Bowel Disease.

BACKGROUND: The immune dysregulation underlying inflammatory bowel disease (IBD) can start years before the diagnosis, but the role of triggering factors and environmental exposures during this period is still uncertain.

METHODS: This single-center case-control study included asymptomatic subjects with an incidental diagnosis of IBD during the colorectal cancer screening program. Twenty-two minerals and 17 metals were determined at diagnosis in hair samples and compared 1:2 to healthy controls.

RESULTS: Six patients with preclinical IBD (3 ulcerative colitis, 67% left-sided; 3 Crohn's disease, 100% ileal, 67% inflammatory behavior) and 13 healthy non-IBD controls were included. No relevant occupational exposures were identified. We found statistically significant higher levels of sodium, potassium, and boron among cases compared to controls; while lower levels of zinc, uranium, copper, and germanium were observed.

CONCLUSIONS: A range of environmental exposures can be identified during the preclinical phase of IBD, but their relationship with the symptomatic onset and disease progression should be further explored.