Exposure to per- and polyfluoroalkyl substances and adult cardiometabolic health: a Canadian Health Measures Survey mixture analysis.

backgroundMetabolic syndrome (MetS) is characterized by four cardiometabolic dimensions including central obesity, dyslipidemia, hypertension, and hyperglycemia, which collectively increase the risk of developing cardiovascular disease and type 2 diabetes mellitus. Epidemiological studies suggest that exposure to per- and polyfluoroalkyl substances (PFAS), which are a class of persistent chemicals used for their water and oil repelling properties, may also contribute to poor cardiometabolic health. We examined associations between exposure to mixture of PFAS and cardiometabolic health among a nationally representative sample of adults living in Canada.

methodsWe used cross-sectional data from 1071 adults aged 20 to 79 from the Canadian Health Measures Survey cycles 2, 5 and 6 (2009–2011, 2016–2019). We examined plasma concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA). We examined MetS, a derived cardiometabolic risk score (CMRS), and their individual cardiometabolic components. We used quantile g-computation (qgcomp) to examine joint associations between the PFAS mixture and cardiometabolic outcomes, and qgcomp weights to determine individual PFAS contributions to the overall mixture effect. Furthermore, we used modified Poisson and linear regression to estimate associations for individual PFAS plasma concentrations and compare with our qgcomp results. Analyses were stratified by sex.

resultsThe prevalence of MetS is 27% in adults living in Canada. In qgcomp models, we observed null associations between the PFAS mixture and both MetS (prevalence ratio: 0.90; 95% CI: 0.74, 1.19) and CMRS (regression index: -0.10; 95% CI: -0.32, 0.12). Each one-quartile increase in the PFAS mixture was associated with 1.2% higher glycated hemoglobin (HbA1c) levels among total population and 1.6% among females, with PFNA contributing most to the joint associations. The PFAS mixture showed null associations with other MetS components. Results from our linear regression models corroborated the findings from the mixture analysis with directions consistent with the qgcomp effect estimates and weights.

conclusionUsing cross-sectional data from a nationally representative sample of adults living in Canada, our findings suggest that a mixture of PFAS may adversely affect glucose metabolism. Further prospective studies are needed to corroborate these findings and establish temporality.