title: Changes in iodine excretion in 50-69-y-old denizens of an Arctic society in transition and iodine excretion as a biomarker of the frequency of consumption of traditional Inuit foods.
abstract: BACKGROUND
  Iodine intake in Greenland has been hypothesized to exceed 10 times the recommended amount. The transition from a traditional Arctic society may change the iodine intake, but no field studies have been performed.
  
  
  OBJECTIVE
  We aimed to ascertain iodine intakes, factors affecting iodine intake in circumpolar populations, and the usefulness of urinary iodine excretion as a biomarker for validation of Inuit food-frequency questionnaires.
  
  
  METHODS
  Data were collected in a cohort study of 4 Greenland population groups: Inuit living in the capital city, the major town, and settlements in East Greenland and non-Inuit. Supplement use and lifestyle factors were evaluated with questionnaires, and dietary habits were ascertained with a food-frequency questionnaire. Iodine was measured in spot urine samples.
  
  
  RESULTS
  One percent of the population of Greenland was invited, and the participation rate was 95%. Less than 5% of Inuit but 55% of non-Inuit had urinary iodine excretion < 50 microg/24 h. Median urinary iodine excretion declined with the degree of decrease in the traditional lifestyle: it was 198, 195, 147, and 58 microg/24 h among Inuit in settlements, town, and city and in non-Inuit, respectively (P < 0.001). Participants were divided into diet groups calculated from Inuit food frequency. Iodine excretion decreased with increasing intake of imported foods (P < 0.001). In regression models, type of diet and the subject's lifestyle, sex, weight, ethnicity, and intake of iodine-containing supplements affected urinary iodine excretion.
  
  
  CONCLUSIONS
  Circumpolar non-Inuit are at risk of iodine deficiency. Departure from the traditional Inuit diet lowers iodine intake, which should be monitored in Arctic societies. Urinary iodine excretion may be a useful biomarker of traditional Inuit food frequency.
authors.affiliation: Department of Endocrinology and Medicine, Aalborg Hospital, Aarhus University Hospital, Denmark. stiga@dadlnet.dk
authors.forename: Stig
authors.initials: S
authors.lastname: Andersen
authors.forename: Bodil
authors.initials: B
authors.lastname: Hvingel
authors.forename: Kent
authors.initials: K
authors.lastname: Kleinschmidt
authors.forename: Torben
authors.initials: T
authors.lastname: Jørgensen
authors.forename: Peter
authors.initials: P
authors.lastname: Laurberg
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D004032:Diet; D004034:Diet Surveys; D019587:Dietary Supplements; D005247:Feeding Behavior / Q000208:ethnology*; D005260:Female; D006116:Greenland; D006801:Humans; D004930:Inuit; D007455:Iodine / Q000008:administration & dosage* / Q000172:deficiency / Q000652:urine*; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009751:Nutritional Requirements; D009752:Nutritional Status; D011795:Surveys and Questionnaires / Q000592:standards*
chemical_list: D015415:Biomarkers; D007455:Iodine