Analysis of circulating cytokines and biomarkers of energy metabolism revealed that PCB 126 increases inflammation and alters insulin and related markers. Male Ldlr−/− mice were fed an atherogenic diet for 14 weeks and exposed to PCB 126 (1 μmol/kg) at weeks 2 and 4. Fecal samples were collected at the start of the study, 72 hours, 4 weeks, and at sacrifice (12 weeks) post first PCB 126 exposure. (A) Quantification of circulating cytokines (MAGPIX technology). PCB 126 increased Interferon gamma-induced protein (IP-10) plasma levels. (B) Quantification of circulating markers of energy metabolism (MAGPIX technology). PCB 126 increased plasma levels of insulin, c-peptide, and glucose-dependent insulinotropic peptide (GIP). PCB 126 reduced plasma levels of glucagon-like peptide 1 (GLP-1) Data are presented as mean ± S.E.M (n=9–10 per group; Student’s t-test). Statistical significance is denoted by * (p<0.05).