Changes in plasma levels of perfluoroalkyl substances (PFASs) are related to increase in carotid intima-media thickness over 10 years – a longitudinal study

Abstract

Since cross-sectional studies might be subject to reverse causation and confounding, longitudinal studies are preferable. The independent variable was split into a between-individual component, which is the first observation for the individual, and a within-individual component, which is the difference between the measurements at future time points and the first measurement. [...]the between-individual component is related to the mean of the three measurements of IMT, while the between-individual component, as a single term, relates the change in each PFAS to the change in IMT. The reason for this discrepancy between the studies is not known, but might be due to the fact that the studies were conducted in very different age-groups and in countries with different exposures of the PFASs. Since cross-sectional studies might be subject to reverse causation and confounding, longitudinal studies are preferable. [...]the present longitudinal study provides a higher level of evidence that PFASs could interfere with atherosclerosis formation, although only randomized interventions could provide the final evidence in this respect. Another recently highlighted mechanism of PFASs is that PFASs might influence circulating microparticles, being markers of endothelial dysfunction constituting an early step in atherosclerosis formation [23]. [...]since many mechanisms could potentially link PFASs exposure to atherosclerosis, we hope that the previous and present findings of a link between PFASs and atherosclerosis in humans will inspire future experimental work to gain further mechanistic insights.