Organophosphate esters exposure associated with increased risk of sleep problems

Organophosphate esters (OPEs), commonly employed as flame retardants and plasticizers, have raised increasing concern due to their potential impacts on human health. Despite their widespread use, population-based evidence regarding their relationship with sleep health remains scarce.In this research, we examined data from the 2013-2016 cycles of the U.S. National Health and Nutrition Examination Survey (NHANES) to investigate the relationship between urinary OPE metabolites and sleep outcomes. The analysis included 2,606 participants who had complete data on both exposure and outcomes. Multivariable linear and logistic regression models were applied to examine associations, while restricted cubic spline models were used to test for potential nonlinear dose-response patterns. To account for combined exposure, we further conducted Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) regression. Our findings showed that dibutyl phosphate (DBUP) was inversely related to sleep duration and exhibited nonlinear associations with sleep indicators. Mixed-exposure analyses indicated that higher cumulative levels of OPEs were linked to shorter sleep duration. Additionally, bis(1-chloro-2-propyl) phosphate (BCPP) was positively related to self-reported sleep problems, particularly among older participants. In general, the findings indicate that exposure to OPEs, particularly DBUP (which originates from tri-n-butyl phosphate, TNBP) and BCPP (derived from tris(2-chloro-isopropyl) phosphate, TCPP), may be associated with sleep disturbances among the U.S. population. Additional mechanistic and long-term studies are needed to validate these associations.