Trends in Exposure to Polyfluoroalkyl Substances and Association with Metabolic Syndrome

Abstract

The per-and polyfluoroalkyl substances (PFAS) are a unique group of synthetic compounds found in myriad commercial applications, including non-stick cook ware, food packaging and firefighting foam. The primary pathway for PFAS exposure in humans is via diet, with fish being the primary dietary source. Laboratory and epidemiologic studies have shown positive associations between human PFAS exposure and several metabolic disturbances. Using data from the National Health and Nutrition Examination Survey (NHANES) from 2003-2018, we: 1) conducted a trend analysis to assess mean PFAS concentration, and 2) examined associations between seafood consumption, serum PFAS levels, and metabolic syndrome. The data show a decline in serum PFAS concentrations by 8%, 14%, 11%, 11% and 20% for PFHxS, PFNA, PFDA, PFUnA and MePFOSA, respectively, per survey cycle. Significant associations between increased fish consumption and serum PFAS levels were also observed. Greater consumption of scallops was associated with 15%, 18% and 5% higher serum concentrations of PFNA, PFDA and PFUnA, respectively. For PFDA, increased consumption of cod and salmon were associated with 37% and 16% higher serum PFAS levels, respectively. For PFUnA, higher tuna consumption was associated with an 18% increase, a 64% increase for cod, a 70% increase for flatfish, and a 20% increase for salmon respectively. Increasing serum levels of PFDA and PFUnA were associated with 30% (PR= 0.70, 95% CI (0.54, 0.91), and 51% (PR= 0.49, 95% CI (0.29, 0.81) decreased prevalence of metabolic syndrome, respectively. Despite decreasing serum PFAS levels, significant differences in PFAS concentrations by non-modifiable factors such as race/ethnicity and gender persist. Further exploration of exposure pathways is required to determine risk profiles of PFAS exposure by demographic group for population-based risk reduction.