Association Between Benzene and Other Volatile Organic Compounds Exposure and Diabetes Mellitus Among Korean Adults: Findings from the Nationwide Biomonitoring Data

Volatile organic compounds (VOCs), including benzene, are environmental contaminants that are associated with various diseases. We investigated the relationship between urinary benzene metabolite, S-phenylmercapturic acid (SPMA), along with other VOC metabolites, and diabetes mellitus (DM). This cross-sectional study analyzed 1674 adults from the Korea National Health and Nutrition Examination Survey (2020–2021). Insulin resistance (IR) was assessed using the Homeostasis Model Assessment for Insulin Resistance. DM was defined using fasting plasma glucose, HbA1c, and medication history. Logistic regressions were employed to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Quantile g-computation was employed to explore the cumulative effect of VOC mixtures on DM. Urinary SPMA levels were positively associated with fasting plasma glucose and IR. The adjusted OR (95% CI) of the association between urinary SPMA level and DM was 0.95 (0.44–2.05) for the second quartile (Q2), 1.78 (0.90–3.53) for third quartile (Q3), and 2.41 (1.19–4.91) for the highest quartile (Q4) compared to the lowest quartile (Q1). Additionally, the highest quartile of 2-methylhippuric acid (2-MHA) level is associated with DM (OR: 2.42, 95% CI: 1.43–2.10) compared with the lowest quartile. In the quantile g-computation, a quartile increase in the VOC mixture is associated with 1.79-fold (95% CI: 1.32–2.43) increase in the odds of having DM. Among the VOC metabolites, the highest positive weight was assigned to urinary SPMA levels, followed by 2-MHA levels. Our study indicates a positive association between urinary benzene metabolite SPMA and xylene metabolite 2-MHA with DM.