Abstract Summary/Description
Background: Published epidemiological studies on the association between perfluoroalkyl acids (PFAAs) exposure and cognitive functions focus mostly on children, with little information available in adults. Objective: To identify associations between perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS) and cognitive functions in adults 60 years and older. Methods: The study is based on cognitive function tests from the National Health and Nutrition Examination Survey 2011-2014: Word List Learning Test (CERAD_WL), Delayed word recall (CERAD-DR), Animal Fluency test (AF), and digit symbol substitution test (DSST). Study participants scoring in the lowest 25th percentile of each cognitive assessment calculated from the full aggregate sample were identified as low cognitive performers (LCP). Multivariate linear and logistic regressions were performed to analyze the relationship between the outcomes and each PFAA in the whole and stratified by sex group. Result: In males, there are statistically significant associations of PFOS with decreased DSST and higher odds of LCP in DSST, whereas in females an improved DSST score is associated with PFOA or PFHxS. In addition, higher level of PFNA or PFOS are associated with decreased odds of WL-LCP and DR-LCP in females. Conclusion: This is the first report of a positive association of PFOS with decreased DSST in male adults, and sex differences in the relationship between several cognitive test scores and PFAAs. Because of the many associations evaluated, the possibility that the reported correlations were due to chance cannot be dismissed.
