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 4.2 mg/dL per interquartile 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 interquartile 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.

Examining confounding by diet in the association between perfluoroalkyl acids and serum cholesterol in pregnancy

“…During pregnancy blood lipids are substantially elevated and these changes are not believed to be atherogenic (Piechota and Staszewski, 1992). Putting clinical relevance aside our results are in line with a previous report form the Norwegian Mother and Child Cohort study (Starling et al, 2014) and the National Health and Nutrition Examination Survey 2003(Jain, 2013. Combined the results from these studies suggest that despite physiological changes associated with pregnancy (Carter 1990), both PFOS and PFOA appear to influence cholesterol level in pregnant subjects in a similar way as has been observed in non-pregnant subjects.…”

“…In terms of magnitude the associations between both PFOS and PFOA with total serum cholesterol was comparable to that observed for high saturated fat intake during pregnancy. The positive association observed between serum concentrations of PFOS and PFOA with total cholesterol in our study is in line with what has previously been reported among the general public (Eriksen et al, 2013;Nelson et al, 2010), in highly exposed populations (Costa et al, 2009;Frisbee et al, 2010;Olsen et al, 2003;Sakr et al, 2007aSakr et al, , 2007bSteenland et al, 2009), and in pregnant women (Jain, 2013;Starling et al, 2014). The strength of the associations reported in these studies has, however, varied considerably.…”

“…Previous studies have suggested that some PFAAs may be associated with HDL rather than LDL cholesterol (Chateau- Degat et al, 2010;Starling et al, 2014) but this could not be verified in our study. However, total cholesterol is still a strong predictor for cardiovascular disease risk and the LDL fraction accounts for around 60-70% of the total cholesterol (Langsted et al, 2008).…”

“…These studies include both occupationally exposed workers, subjects from communities with high exposure levels (Costa et al, 2009;Frisbee et al, 2010;Olsen et al, 2003;Sakr et al, 2007aSakr et al, , 2007bSteenland et al, 2009) and the general population (Eriksen et al, 2013;Nelson et al, 2010) including pregnant women (Jain, 2013;Starling et al, 2014). However, several studies have reported no association (Emmett et al, 2006;Olsen et al, 2000Olsen et al, , 2012.…”

Inter-individual, inter-city, and temporal trends of per- and polyfluoroalkyl substances in human milk from Swedish mothers between 1972 and 2016

“…21 Clearly, the effect of PFAS exposure on the health of both mother and baby is of concern. Several studies have reported links between PFAA exposure and perturbation in lipid metabolism [22][23][24] and glucose tolerance 24 during pregnancy. Exposure to some PFAAs during early life stages has also been linked to adverse health effects such as reduced birth weight and immune toxicity.…”