Long-term exposure to ambient benzene and incident type 2 diabetes mellitus in a national cohort: The modifying effect of genetic susceptibility.

BACKGROUND

Epidemiological evidence on the link between long-term ambient benzene exposure and type 2 diabetes mellitus (T2DM) risk is insufficient.

METHODS

We analyzed 329,210 participants from the UK Biobank (2006-2010) using spatiotemporal modeling to evaluate benzene concentrations. We employed Cox proportional hazards models to explore the relationship between benzene exposure and T2DM onset. Causal relationships were examined using negative control outcomes. Moreover, we assessed interaction effects using relative excess risk due to interaction (RERI) and attributable proportion (AP) to understand genetic susceptibility's role in benzene exposure-related T2DM risk.

RESULTS

Over a median 11.8-year follow-up, 11,552 T2DM cases were recorded. The Cox model revealed a hazard ratio of 1.30 (95 % CI: 1.27, 1.33) per IQR (interquartile range) increase in benzene. Genetic factors significantly modified impact of benzene on T2DM risk, with those high genetically predisposed and the highest benzene exposure showing the highest risk and calculated RERI and AP were 1.23 and 0.20, respectively.

CONCLUSION

Our study evidences a causal link between benzene exposure and increased T2DM risk, exacerbated by genetic susceptibility. These insights suggest that reducing air pollution might mitigate T2DM development.