Associations of perfluorooctane sulfonate alternatives and serum lipids in Chinese adults

Background: Chlorinated polyfluorinated ether sulfonic acids (Cl-PFESAs), a group of perfluorooctane sulfonate (PFOS) alternatives, can be widely observed in humans and environmental matrices. However, associations between exposure to Cl-PFESAs and serum lipid levels in adults are unknown. Objective: To explore the relationships between Cl-PFESA levels and serum lipid levels in adults. Methods: We analyzed 1238 adults from the Isomers of C8 Health Project, a cross-sectional study conducted in China from July 2015 to October 2016. The average age of the participants was 61.98 ± 14.40 years. We quantified two select legacy per- and perfluoroalkyl substances [perfluorooctanoic acid (PFOA) and PFOS] and their alternatives (6:2 and 8:2 Cl-PFESAs). We also measured four serum lipids: low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), total cholesterol (TC), and triglycerides (TG). We used generalized linear models to estimate the associations between PFASs and serum lipids, with PFASs defined as either a categorical variable divided into quartiles or as a continuous variable. Results: We found that 6:2 Cl-PFESA was positively associated with serum TC and LDL-C. For instance, LDL-C levels in the highest quartile of 6:2 Cl-PFESA exposure (Q4) were significantly higher than those in the lowest quartile (Q1) [β: 0.19, 95% confidence interval (CI): 0.08, 0.30]. Further analysis showed that one ln-ng/mL increase in 6:2 Cl-PFESA exposure corresponded to a 0.10 mmol/L (95% CI: 0.05, 0.16) LDL-C increase, and that exposure to 8:2 Cl-PFESA was negatively correlated with HDL-C (β: −0.03, 95% CI: −0.05, −0.01). TC had a similar relationship with both 6:2 Cl-PFESA and legacy PFASs. Participants with a BMI ≥ 25 kg/m² exhibited a stronger association between 6:2 Cl-PFESA and TC. Conclusions: Our findings make the novel suggestion that exposure to Cl-PFESAs are adversely associated with serum lipid levels, and that such associations are also observed in legacy PFASs. Increased investigation into the effects of Cl-PFESAs exposure on human health is warranted.