Serum perfluoroalkyl acids concentrations and memory impairment in a large cross-sectional study
Valentina Gallo1, Giovanni Leonardi, Carol Brayne
1Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, UK.
Objectives:
To examine the cross-sectional association between serum perfluorooctanate (PFOA), perfuorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonate (PFHxS) concentrations with self-reported memory impairment in adults and the interaction of these associations with diabetes status.
Design:
Cross-sectional study.
Setting:
Population-based in Mid-Ohio Valley, West Virginia following contamination by a chemical plant.
Participants:
The C8 Health Project collected data and measured the serum level of perfluoroalkyl acids (PFAAs) of 21 024 adults aged 50+ years.
Primary Outcome Measure:
Self-reported memory impairment as defined by the question 'have experienced short-term memory loss?'
Results:
A total of 4057 participants self-reported short-term memory impairment. Inverse associations between PFOS and PFOA and memory impairment were highly statistically significant with fully adjusted OR=0.93 (95% CI 0.90 to 0.96) for doubling PFOS and OR=0.96 (95% CI 0.94 to 0.98) for doubling PFOA concentrations. Comparable inverse associations with PFNA and PFHxS were of borderline statistical significance. Inverse associations of PFAAs with memory impairment were weaker or non-existent in patients with diabetes than overall in patients without diabetes.
Conclusions:
An inverse association between PFAA serum levels and self-reported memory impairment has been observed in this large population-based, cross-sectional study that is stronger and more statistically significant for PFOA and PFOS. The associations can be potentially explained by a preventive anti-inflammatory effect exerted by a peroxisome proliferator-activated receptor agonist effect of these PFAAs, but confounding or even reverse causation cannot be excluded as an alternative explanation.
