Association between Blood Trihalomethane Concentrations and the Risk of Dyslipidemia: Nationally Representative Cross-Sectional Study

Experimental studies have indicated that exposure to disinfection byproducts (DBPs) may affect the lipid synthesis. However, epidemiological evidence is sparse. This study aimed to investigate the relationship between blood trihalomethane (THM) exposure and the risk of dyslipidemia from the National Health and Nutrition Examination Survey 2005-2018. We included adults (n = 16,159) whose blood concentrations of chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM) were quantified. Multivariable logistic regression revealed significantly elevated dyslipidemia risks in the highest group of TCM [adjusted odds ratios (ORs) = 1.30, 95% confidence intervals (CIs): 1.15-1.47], BDCM (1.23,1.07-1.42), TBM (1.35, 1.08-1.68), and total THMs (TTHMs; sum of all four THMs) (1.30, 1.14-1.48). In subgroup analysis, these associations were stronger among young/middle-aged individuals. In Weighted Quantile Sum regression and Quantile G-Computation analysis, combined THM exposure was positively associated with dyslipidemia risk. Our study provides new evidence of a positive association between blood THM concentrations and the risk of dyslipidemia, underscoring the need for further research to confirm these findings and explore the underlying mechanisms.