title: Perfluorooctanoic acid and chronic kidney disease: Longitudinal analysis of a Mid-Ohio Valley community.
abstract: BACKGROUND
  Perfluorooctanoic acid (PFOA) is an environmentally persistent chemical found at low-levels in the serum of almost all U.S. residents. Chronic kidney disease (CKD) has been positively associated with serum PFOA in prior cross-sectional studies and in one occupational mortality study, while other investigations have found no association between kidney function and PFOA.
  
  
  METHODS
  We conducted a longitudinal analysis of chronic kidney disease among adults, aged ≥20 years, (N=32,254) in a Mid-Ohio Valley community cohort, exposed to high PFOA levels from contaminated drinking water. Estimated retrospective yearly serum PFOA concentrations (1951-2011) were previously modeled in this population. Information about lifetime history of CKD diagnosis was collected during surveys in 2008-2011; self-reported CKD diagnoses were validated through medical record review. Using a Cox proportional hazards model, we retrospectively examined the association between validated adult onset CKD, and modeled PFOA exposure, from time of first exposure. We also analyzed data for the cohort prospectively, among people with no CKD diagnosis prior to enrollment in a baseline survey in 2005-2006. Both the full cohort and a non-diabetic subset were analyzed, retrospectively and prospectively.
  
  
  RESULTS
  Neither in retrospective nor in prospective analyses did we find a significant (α=0.05) trend between PFOA exposure and CKD. In the full cohort, estimated hazard ratios by quintile of cumulative serum PFOA in the retrospective analysis were 1.00 (referent), 1.26, 1.12, 1.12 and 1.24 (trend test for log cumulative exposure: p=0.80).
  
  
  CONCLUSIONS
  Our analyses suggest that CKD is not associated with exposure to PFOA.
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322, USA. Electronic address: rdhingra@emory.edu.
authors.forename: Radhika
authors.initials: R
authors.lastname: Dhingra
authors.affiliation: Department of Health Policy and Management, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322, USA. Electronic address: clally@emory.edu.
authors.forename: Cathy
authors.initials: C
authors.lastname: Lally
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322, USA. Electronic address: ldarrow@emory.edu.
authors.forename: Lyndsey A
authors.initials: LA
authors.lastname: Darrow
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322, USA. Electronic address: mklein@emory.edu.
authors.forename: Mitch
authors.initials: M
authors.lastname: Klein
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322, USA. Electronic address: awinqui@emory.edu.
authors.forename: Andrea
authors.initials: A
authors.lastname: Winquist
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322, USA. Electronic address: nsteenl@emory.edu.
authors.forename: Kyle
authors.initials: K
authors.lastname: Steenland
mesh_terms: D002210:Caprylates / Q000097:blood* / Q000633:toxicity; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004785:Environmental Pollutants / Q000097:blood* / Q000633:toxicity; D005260:Female; D005466:Fluorocarbons / Q000097:blood* / Q000633:toxicity; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000139:chemically induced / Q000453:epidemiology*; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis
chemical_list: D002210:Caprylates; D004785:Environmental Pollutants; D005466:Fluorocarbons; C023036:perfluorooctanoic acid
keywords: Chronic kidney disease; Cohort; Longitudinal; Perfluorooctanoic acid