Perfluoroalkyl substances and lipid concentrations in plasma during pregnancy among women in the Norwegian Mother and Child Cohort Study

Abstract

Background: Perfluoroalkyl substances (PFASs) are widespread and persistent environmental pollutants. Previous studies, primarily among non-pregnant individuals, suggest positive associations between PFAS levels and certain blood lipids. If there is a causal link between PFAS concentrations and elevated lipids during pregnancy, this may suggest a mechanism by which PFAS exposure leads to certain adverse pregnancy outcomes, including preeclampsia.

Methods: This cross-sectional analysis included 891 pregnant women enrolled in the Norwegian Mother and Child (MoBa) Cohort Study in 2003-2004. Non-fasting plasma samples were obtained at mid-pregnancy and analyzed for nineteen PFASs. Total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured in plasma. Linear regression was used to quantify associations between each PFAS exposure and each lipid outcome. A multiple PFAS model was also fitted.

Results: Seven PFASs were quantifiable in >50% of samples. Perfluorooctane sulfonate (PFOS) concentration was associated with total cholesterol, which increased 4.2mg/dL per inter-quartile shift (95% CI=0.8, 7.7) in adjusted models. Five of the seven PFASs studied were positively associated with HDL cholesterol, and all seven had elevated HDL associated with the highest quartile of exposure. Perfluoroundecanoic acid showed the strongest association with HDL: HDL increased 3.7 mg/dL per inter-quartile shift (95% CI=2.5, 4.9).

Conclusion: Plasma concentrations of PFASs were positively associated with HDL cholesterol, and PFOS was positively associated with total cholesterol in this sample of pregnant Norwegian women. While elevated HDL is not an adverse outcome per se, elevated total cholesterol associated with PFASs during pregnancy could be of concern if causal.

Keywords: BMI; CI; DAG; HDL; IQR; LDL; LOQ; MBRN; Medical Birth Registry of Norway; MoBa; Norwegian Mother and Child Cohort Study; PFASs; PFDA; PFHpS; PFHxS; PFNA; PFOA; PFOS; PFUnDA; Perfluoroalkyl substances; Perfluorooctane sulfonate; Perfluorooctanoic acid; The Norwegian Mother and Child Cohort Study; body mass index; confidence interval; directed acyclic graph; high-density lipoprotein; inter-quartile range; limit of quantification; low-density lipoprotein; perfluoroalkyl substances; perfluorodecanoic acid; perfluoroheptane sulfonate; perfluorohexane sulfonate; perfluorononanoic acid; perfluorooctane sulfonate; perfluorooctanoic acid; perfluoroundecanoic acid.

Figure 1

Weighted linear regression coefficients for single and multiple pollutant models of the association between natural log-transformed PFASs (ln-ng/mL) and HDL cholesterol (mg/dL).