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.

Figure 1. Distributions of plasma PFOA and PFOS levels.

(A) Distribution of plasma PFOA levels (ng/mL) of the study population. (B) Distribution of plasma PFOS levels (ng/mL) of the study population.

Figure 2. Associations between plasma PFOA and PFOS levels and total cholesterol.

The Figure illustrates differences in total cholesterol levels according to eight exposure groups of (A) PFOA and (B) PFOS. The lowest exposure groups are used as reference (open dots). The dots are placed at the median of the eight exposure categories. Models are adjusted (sex, age, years of school attendance, body mass index, smoking status, alcohol intake, egg intake, animal fat intake and physical activity).