Parental occupations and risk for Crohn’s disease in children

Background and objectives: Lacunae exist on the identity of specific environmental risk factors that associate with Crohn’s disease (CD). We hypothesized that indirect exposures acquired via the parents’ occupation may confer susceptibility. Methods: A case–control study based on children diagnosed with CD (prior to age 20) at a tertiary care gastroenterology clinic in Montreal, Canada was carried out. Population- and hospital-based controls without IBD were selected. Information on occupations held by the parents was acquired from interview. Jobs were coded using the Canadian National Occupational Classification for Statistics. Associations were examined using logistic regression accounting for potential confounders. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated. Results: A total of 466 cases and 335 controls were studied. The mean (±SD) age of the cases (12.4 ± 3.2) was slightly higher than controls (10.5 ± 4.9). Gender and ethnicity were equally distributed between the groups. Logistic regression analysis suggested that children whose fathers worked as retail salespersons/sales clerks [odds ratio (OR) 3.6, 95% confidence interval (CI) 1.2–11.1], and whose mothers worked as administrative secretaries (OR 3.2, 95% CI 1.6–6.4), were more likely to be at risk for CD. Mothers who worked as either early childhood educators (OR 2.3, 95% CI 0.85–6.2) or as clerks (OR 2.8, 95% CI 0.8–9.9) also appeared to confer risks, but these associations were statistically not significant. Conclusion: Parental occupations related to ‘social mixing’ that can potentially enhance exposure to infectious agents, appear to confer higher risk for CD in children.