title: Cross-sectional association between polyfluoroalkyl chemicals and cognitive limitation in the National Health and Nutrition Examination Survey.
abstract: OBJECTIVE
  Our limited understanding of how polyfluoroalkyl chemicals (PFCs) may impact on human health suggests the potential for a protective impact on brain health. This study was designed to explore the association between PFCs and cognitive ability in older adults.
  
  
  METHODS
  We assessed the association between four PFCs, perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonic acid (PFHxS), and self-reported limitation due to difficulty remembering or periods of confusion using data from participants aged 60-85 years from the 1999-2000 and 2003-2008 National Health and Nutrition Examination Surveys. We also considered whether diabetic status or diabetic medication use modifies this association in light of in vitro evidence that PFCs may act on the same receptors as some diabetic medications.
  
  
  RESULTS
  In multivariable adjusted models, point estimates suggest a protective association between PFCs and self-reported cognitive limitation (odds ratio, OR; 95% confidence interval, CI) for a doubling in PFC concentration: PFOS (OR, 0.90; 95% CI, 0.78, 1.03), PFOA (OR, 0.92; 95% CI, 0.78, 1.09), PFNA (OR, 0.91; 95% CI, 0.79, 1.04) and PFHxS (OR, 0.93; 95% CI, 0.82, 1.06). The protective association was concentrated in diabetics, with strong, significant protective associations in nonmedicated diabetics.
  
  
  CONCLUSIONS
  This cross-sectional study suggests that there may be a protective association between exposure to PFCs and cognition in older adults, particularly diabetics.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, MA 02215, USA. melindacpower@gmail.com
authors.forename: Melinda C
authors.initials: MC
authors.lastname: Power
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Webster
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Baccarelli
authors.forename: Marc G
authors.initials: MG
authors.lastname: Weisskopf
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017738:Alkanesulfonic Acids; D002210:Caprylates; D015984:Causality; D003072:Cognition Disorders / Q000453:epidemiology*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000453:epidemiology*; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D005466:Fluorocarbons; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009749:Nutrition Surveys; D020011:Protective Agents; D013451:Sulfonic Acids; D014481:United States / Q000453:epidemiology
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D005466:Fluorocarbons; D020011:Protective Agents; D013451:Sulfonic Acids; C471071:perfluorohexanesulfonic acid; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid