Background: Increased diabetes mortality has been reported in workers exposed to perfluorooctanoic acid (PFOA). We analyzed the relationships among serum PFOA, type II diabetes, and fasting glucose in a population with high levels of serum PFOA resulting from drinking contaminated water.
Methods: The study population was adults participating in a health survey in 2005-2006 (N=54,468). Subjects reported prevalent diabetes, age at diagnosis, and provided blood in which serum PFOA and glucose levels were measured. We conducted a case-control analysis restricted to long-time residents (> or =20 years, N=13,922), to maximize the likelihood that serum PFOA levels in 2005 reflected previous exposure. Cases (N=1055) were restricted to those with medical record validation and at least 10-year residence prior to diagnosis. We also studied fasting glucose and serum PFOA in a subset (N=21,642).
Results: Median serum PFOA was 28 ng/ml, compared with 4 ng/ml in the general US population. Reported diabetes prevalence was 7.8%, similar to what was expected. Adjusted for confounders, all upper deciles of serum PFOA had a decreased risk of diabetes compared with the lowest (odds ratios-ORs by decile, 1.00, 0.71, 0.60, 0.72, 0.65, 0.65, 0.87, 0.58, 0.62, 0.72). There was no consistent pattern between fasting serum glucose and PFOA (glucose by decile, 94, 95, 95, 93, 94, 92, 92, 92, 92, 93, adjusted for confounders).
Conclusions: Our findings do not demonstrate an association between PFOA and either type II diabetes or fasting glucose level. Our data are limited by their cross-sectional nature, and do not preclude the possibility of a causal relationship.