title: Associations between plasma persistent organic pollutant levels and blood pressure in Inuit adults from Nunavik.
abstract: BACKGROUND
  Recent evidence suggests that exposure to persistent organic pollutants (POPs) increases the risk of hypertension in environmentally exposed populations. High POP levels have been detected in Arctic populations and the exposure is related to high consumption of fish and marine mammals, which represent the traditional diet of these populations.
  
  
  OBJECTIVE
  We examined the associations between polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and hypertension among Inuit from Nunavik (Quebec, Canada).
  
  
  METHODS
  A complete set of data was obtained for 315 Inuit≥18years who participated in the "Santé Québec" health survey that was conducted in the 14 villages of Nunavik in 1992. Fourteen polychlorinated biphenyls (PCBs) and 8 OC pesticides or their metabolites were measured in plasma samples using gas chromatography with electron capture detection. Blood pressure (BP) was measured using a standardized protocol and information regarding anti-hypertensive medication was obtained through questionnaires. The associations between log-transformed POPs and hypertension (systolic BP≥140mmHg, diastolic BP≥90mmHg or anti-hypertensive medication) were analyzed using multiple logistic regressions.
  
  
  RESULTS
  Total PCBs as well as the sum of non-dioxin-like PCBs were significantly associated with higher risk of hypertension. Furthermore, the risk of hypertension increased with higher plasma concentrations of congeners 101, 105, 138 and 187. Models adjusted for BP risk factors became significant after including n-3 polyunsaturated fatty acids (PUFAs) and further adjustment for lead and mercury did not change the results. Regarding OC pesticides, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) was associated with increased risk of hypertension while inverse associations were observed with p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), β-hexachlorocyclohexane (HCH) and oxychlordane.
  
  
  CONCLUSIONS
  Some PCB congeners were associated with higher risk of hypertension in this highly exposed population. Most associations became significant after including n-3 PUFAs in the models. However, the analyses of OC pesticides revealed divergent results, which need to be confirmed in further cohort and experimental studies.
authors.affiliation: Axe santé publique et pratiques optimales en santé, Centre de recherche du CHU de Québec, Canada. beatriz.valera@crchul.ulaval.ca
authors.forename: Beatriz
authors.initials: B
authors.lastname: Valera
authors.forename: Pierre
authors.initials: P
authors.lastname: Ayotte
authors.forename: Paul
authors.initials: P
authors.lastname: Poirier
authors.forename: Eric
authors.initials: E
authors.lastname: Dewailly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001110:Arctic Regions; D001794:Blood Pressure / Q000187:drug effects*; D003633:Dichlorodiphenyl Dichloroethylene / Q000097:blood; D004032:Diet; D004147:Dioxins / Q000097:blood; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000097:blood*; D015525:Fatty Acids, Omega-3 / Q000097:blood; D005260:Female; D005399:Fishes; D001556:Hexachlorocyclohexane / Q000097:blood; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000097:blood; D006973:Hypertension / Q000139:chemically induced / Q000453:epidemiology*; D004930:Inuit; D008297:Male; D008628:Mercury / Q000097:blood; D008875:Middle Aged; D010575:Pesticides / Q000097:blood*; D011078:Polychlorinated Biphenyls / Q000097:blood*; D000072317:Polychlorinated Dibenzodioxins / Q000097:blood; D011792:Quebec / Q000453:epidemiology; D055815:Young Adult
chemical_list: D004147:Dioxins; D004785:Environmental Pollutants; D015525:Fatty Acids, Omega-3; D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D000072317:Polychlorinated Dibenzodioxins; D003633:Dichlorodiphenyl Dichloroethylene; D001556:Hexachlorocyclohexane; D011078:Polychlorinated Biphenyls; D008628:Mercury; C023888:beta-hexachlorocyclohexane
keywords: Blood pressure; Inuit; Nunavik; Organochlorine (OC) pesticides; Persistent organic pollutants (POPs); Polychlorinated biphenyls (PCBs)