Potential effect of co-exposure to Per- and polyfluoroalkyl substances on the risk of insomnia

• Individual exposure to four PFASs increase the risk of insomnia in adult women. • The four PFASs causing insomnia are PFDA, PFUdA, PFNA and 6:2 Cl-PFESA. • Exposure to PFASs mixtures above the 50th percentile increase the risk of insomnia. • Evidence for association between co-exposure to PFASs and insomnia is insufficient. Per- and polyfluoroalkyl substances (PFASs) can interfere with the endocrine and central nervous systems, and may further disrupt sleep quality. To address this concern, we investigated the association between the whole-blood levels of several PFASs and insomnia. A total of 394 female adults were recruited and 30 PFASs were measured. Multivariate logistic regression models were employed to test the individual associations between the level of each component and insomnia. Quantile-based g-computation and Bayesian kernel machine regression models were used to estimate whether co-exposure to PFASs increased the risk of insomnia. The individual exposure analyses revealed that the levels of perfluorodecanoic acid [odds ratio (OR) = 1.22, 95% confidence interval (CI): 1.03, 1.45)], perfluoroundecanoic acid [OR = 1.59 (95% CI: 1.02, 2.47)], perfluorononanoic acid [OR = 2.20 (95% CI: 1.15, 4.21)], and 6:2 chlorinated polyfluorinated ether sulfonate [OR for quartile 2 (Q2) = 2.07 (95% CI: 1.10, 3.88), OR for Q4 = 2.27 (95% CI: 1.17, 4.42)] were positively associated with the risk of insomnia. Our findings nonetheless suggest that reducing exposure to such substances would probably lower the risk of insomnia in adults.