Abstract Background It is well known that the burden of inflammatory bowel disease (IBD) has surged amid profound societal shifts, including industrialization and westernization of lifestyles in modern societies. However, how contemporary occupations, as a key social linkage connecting industrialization and profoundly shaping individual lives, modulate individual susceptibility to IBD remains largely understudied. This study aims to (1) systematically delineate the landscape of associations between occupations and IBD risk, and (2) elucidate the factors through which occupations influence individual susceptibility to IBD. Methods We used robust Poisson regression to assess IBD risk across 353 occupations (coded by SOC2000) in the UK Biobank cohort, with validation in an independent Chinese cohort derived from the Hunan Medical Insurance Database. To further clarify the potential mechanisms behind the identified risk occupations, we employed Cox proportional hazards models to evaluate associations between IBD risk and occupation-related factors, including pollutants (airborne, dust-related, and complex chemical contaminants), occupation-specific behaviors (work-related physical activity, sedentary time, work stress, and night shifts), and occupation-related socioeconomic status. Results Among 120,290 participants, including 9,748 diagnosed with IBD, 10 occupations were identified as associated with an increased risk of IBD, with subgroup analyses revealing 16 and 6 occupations linked to Crohn’s disease (CD) and ulcerative colitis (UC), respectively. The excess risk observed for the skilled trades occupational category was further confirmed in the independent Hunan Medical Insurance Cohort (Figure 2A). High-level exposures to diesel (HR 1.56, 95% CI: 1.14-2.13) and mists (HR 1.31, 95% CI: 1.04-1.66) were associated with an increased risk of IBD, with similar patterns observed for both CD and UC (Figure 2B). Further analyses of behavioral and socioeconomic dimensions showed that lifelong exposure to high levels of occupational physical activity was associated with an elevated IBD risk (HR 1.18, 95% CI: 1.05-1.32), whereas higher occupational social status exerted a protective effect (HR 0.73, 95% CI: 0.66-0.90) with consistent risk reductions observed for CD and UC (Figure 2C). Conclusion: This study systematically presents the occupational landscape of IBD risk, highlighting the impact of high-pollution and high physical activity occupations on individual IBD susceptibility, while further linking industrialization-driven work patterns and social stratification to disease risk. These findings expand the environmental framework of IBD etiology and underscore the importance of integrating occupational factors into future etiologic and preventive research. Conflict of interest Zhou, Yuying: Have no conflict of interest. Dan, Lintao: I have no COI related to submitted program Ruan, Xixian: I disclose no relevant conflict of interest. Deng, Minzi: No conflict of interest Chen, Jie: No conflict of interest Wang, Xiaoyan: No conflict of interest
Zhou et al. (Thu,) studied this question.