title: Prospective associations between persistent organic pollutants and metabolic syndrome: a nested case-control study.
abstract: OBJECTIVE
  Exposure to persistent organic pollutants (POPs) has recently been linked to metabolic syndrome (MetS) and some MetS components. However, prospective evidence in humans is scarce, and the nature of the dose-response relationship is unclear. We evaluated the association between POPs and MetS using a nested-case control study within a community-based Korean cohort.
  
  
  METHODS
  The study subjects were 64 patients newly diagnosed with MetS during a 4-year follow-up, and the controls were 182 subjects without MetS. Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured in stored serum collected at baseline.
  
  
  RESULTS
  The concentrations of most PCBs and some OCPs such as β-hexachlorocyclohexane, hexachlorobenzene, oxychlordane, and heptachlor epoxide predicted the risk for MetS. The POP exposure and MetS showed an inverted U-shaped or a linear association with plateau rather than a linear dose-response association. When the summary measure of the PCBs and OCPs was used, the adjusted odds ratios (ORs) across the quartiles of the summary measure were 1.0, 1.3, 3.8 (95% confidence interval, 1.3-10.7), and 2.1 (Pquadratic=0.013) after adjusting for potential confounders. In the analyses of each of the five MetS components, POP exposure was mainly associated with an increased risk for glucose and lipid metabolism disturbances.
  
  
  CONCLUSIONS
  This study demonstrated that chronic exposure to a mixture of PCBs and OCPs can increase the risk for MetS within the low-dose background exposure range of POPs. As the findings of this study suggest a nonmonotonic dose-response relationship, in vitro and in vivo experimental studies are needed to understand the underlying mechanisms.
authors.affiliation: Department of Preventive Medicine, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, Republic of Korea; Regional Cardiocerebrovascular Center, Kyungpook National University Hospital, 130 Dongdeok-ro, Jung-gu, Daegu 700-721, Republic of Korea.
authors.forename: Yu-Mi
authors.initials: YM
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, Republic of Korea.
authors.forename: Ki-Su
authors.initials: KS
authors.lastname: Kim
authors.affiliation: Department of Biomedical Science, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, Republic of Korea; BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, Kyungpook National University, Republic of Korea.
authors.forename: Se-A
authors.initials: SA
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, Republic of Korea.
authors.forename: Nam-Soo
authors.initials: NS
authors.lastname: Hong
authors.affiliation: Department of Epidemiology and Health Promotion, School of Public Health, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, Republic of Korea.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, Republic of Korea; BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, Kyungpook National University, Republic of Korea. Electronic address: lee_dh@knu.ac.kr.
authors.forename: Duk-Hee
authors.initials: DH
authors.lastname: Lee
mesh_terms: D016022:Case-Control Studies; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology*; D008875:Middle Aged; D016017:Odds Ratio; D010575:Pesticides / Q000097:blood; D011078:Polychlorinated Biphenyls / Q000097:blood
chemical_list: D004785:Environmental Pollutants; D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D011078:Polychlorinated Biphenyls
keywords: Metabolic syndrome; Organochlorine pesticides; Persistent organic pollutants; Polychlorinated biphenyls