Association between Plasma PFOA and PFOS Levels and Total Cholesterol in a Middle-Aged Danish Population

Abstract

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are used in a variety of consumer products and have been detected worldwide in human blood. Recent studies mainly of highly exposed populations have indicated that PFOA and PFOS may affect serum cholesterol levels, but the magnitude of the effect may be inconsistent across exposure levels. The aim of the present cross-sectional study was to investigate the association between plasma PFOA and PFOS and total cholesterol in a general, middle-aged Danish population. The study population comprised 753 individuals (663 men and 90 women), 50–65 years of age, nested within a Danish cohort of 57,053 participants. Blood samples were taken from all cohort members at enrolment (1993–1997) and stored in a biobank at -150°C. Plasma levels of PFOA and PFOS and serum levels of total cholesterol were measured. The associations between plasma PFOA and PFOS levels and total cholesterol levels were analysed by generalized linear models, both crude and adjusted for potential confounders. We observed statistically significant positive associations between both perfluorinated compounds and total cholesterol, e.g. a 4.4 [95% CI = 1.1–7.8] higher concentration of total cholesterol (mg/dL) per interquartile range of PFOA plasma level. Sex and prevalent diabetes appeared to modify the association between PFOA and PFOS, respectively, and cholesterol. In conclusion, this study indicated positive associations between plasma PFOA and PFOS levels and total cholesterol in a middle-aged Danish population, although whether the observed pattern of results reflects a causal association is unclear.

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

“…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.…”

“…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.…”

“…Diet is one obvious candidate as diet may influence both serum cholesterol and PFAA concentrations (Halldorsson et al, 2008;Lichtenstein et al, 1999). Although some studies have accounted for dietary fat intake (Eriksen et al, 2013;Nelson et al, 2010) the importance of this adjustment is usually not reported and other dietary factors than fat are rarely accounted for. Furthermore the strength of the association between PFAAs and serum cholesterol varies considerably between studies and the overall clinical significance in relation to more established risk factors such as age and BMI has been disputed (Kerger et al, 2011).…”

Per- and polyfluorinated substances (PFASs): Environmental challenges

“…Concerning background populations, elevated serum PFOS, PFOA, PFNA levels have been associated positively (and PFHxS negatively) with elevated cholesterol [285,308]. Another study found, however, a positive association with PFHxS [309].…”

“…A transcriptional analysis that found changes in the expression of genes related to cholesterol metabolism and suggested that exposure to PFOA may promote a hypercholesterolemic environment [283] was criticized and deemed unsubstantiated [284]. Decrease of LDL cholesterol with decrease in serum PFOA after exposure to contaminated drinking water was ended, indicated a causal relation [285].…”