title: Effect of seafood mediated PCB exposure on desaturase activity and PUFA profile in Faroese septuagenarians.
abstract: Polychlorinated biphenyl (PCB) exposure may affect serum concentrations of polyunsaturated fatty acids (PUFAs) by inhibiting desaturases ∆5 and ∆6 that drive their synthesis from precursor fatty acids. Such changes in the composition of fatty acids may affect cardiovascular disease risk, which is thought to increase at elevated PCB exposures. This population-based cross-sectional study examined 712 Faroese men and women aged 70-74 years. The serum phospholipid fraction of fasting blood samples was used to determine the PUFA profile, including linoleic acid, dihomo-γ-linolenic acid, arachidonic acid, eicosatrienoic acid, and other relevant fatty acids. Ratios between precursor and metabolite fatty acids were used as proxies for ∆5 and ∆6 desaturase activity. Tertiles of serum-PCB concentrations were used in multiple regression analyses to determine the association between the exposure and desaturase activity. In multiple regression models, PCB exposure was inversely related to the estimated Δ6 desaturase activity resulting in accumulation of precursor fatty acids and decrease in the corresponding product PUFAs. A positive association between PCB and Δ5 desaturation was also found. A relative increase in EA was also observed, though only in the third tertile of PCB exposure. Non-linear relationships between the exposure and the desaturase activity were not found. Consuming fish and seafood may not be translated into beneficial fatty acid profiles if the diet simultaneously causes exposure to PCBs. Although the desaturase estimates were likely influenced by dietary intakes of product PUFAs, the association between PCB exposure and ∆6 desaturase activity is plausible and may affect cardiovascular disease risk.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Harvard University, USA; Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark.
authors.forename: Sandra Søgaard
authors.initials: SS
authors.lastname: Tøttenborg
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Harvard University, USA.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Choi
authors.affiliation: Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway; Clinic of Laboratory Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Kristian S
authors.initials: KS
authors.lastname: Bjerve
authors.affiliation: Department of Occupational Medicine and Public Health, Faroese Hospital System, Torshavn, Faroe Islands.
authors.forename: Pal
authors.initials: P
authors.lastname: Weihe
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Harvard University, USA; Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark. Electronic address: pgrand@hsph.harvard.edu.
authors.forename: Philippe
authors.initials: P
authors.lastname: Grandjean
mesh_terms: D000368:Aged; D003718:Denmark; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D017747:Seafood / Q000032:analysis*
chemical_list: D005231:Fatty Acids, Unsaturated; D011078:Polychlorinated Biphenyls; D044943:Fatty Acid Desaturases
keywords: Cardiovascular disease; Desaturase; Generalized additive models; Polychlorinated biphenyls; Polyunsaturated fatty acids