title: Urinary iodine concentration identifies pregnant women as iodine deficient yet school-aged children as iodine sufficient in rural Niger.
abstract: OBJECTIVE
  To assess iodine status among pregnant women in rural Zinder, Niger and to compare their status with the iodine status of school-aged children from the same households.
  
  
  METHODS
  Seventy-three villages in the catchment area of sixteen health centres were randomly selected to participate in the cross-sectional survey.
  
  
  METHODS
  Salt iodization is mandatory in Niger, requiring 20-60 ppm iodine at the retail level.
  
  
  METHODS
  A spot urine sample was collected from randomly selected pregnant women (n 662) and one school-aged child from the same household (n 373). Urinary iodine concentration (UIC) was assessed as an indicator of iodine status in both groups. Dried blood spots (DBS) were collected from venous blood samples of pregnant women and thyroglobulin (Tg), thyroid-stimulating hormone and total thyroxine were measured. Iodine content of household salt samples (n 108) was assessed by titration.
  
  
  RESULTS
  Median iodine content of salt samples was 5·5 ppm (range 0-41 ppm), 98 % had an iodine content 40 µg/l.
  
  
  CONCLUSIONS
  In this region of Niger, most salt is inadequately iodized. UIC in pregnant women indicated iodine deficiency, whereas UIC of school-aged children indicated marginally adequate iodine status. Thus, estimating population iodine status based solely on monitoring of UIC among school-aged children may underestimate the risk of iodine deficiency in pregnant women.
authors.affiliation: 1Program in International and Community Nutrition,Department of Nutrition,University of California,Davis,One Shields Avenue,Davis,CA 95616,USA.
authors.forename: Sonja Y
authors.identifier: http://orcid.org/0000-0002-4661-277X
authors.initials: SY
authors.lastname: Hess
authors.affiliation: 1Program in International and Community Nutrition,Department of Nutrition,University of California,Davis,One Shields Avenue,Davis,CA 95616,USA.
authors.forename: Césaire T
authors.identifier: http://orcid.org/0000-0003-0634-3226
authors.initials: CT
authors.lastname: Ouédraogo
authors.affiliation: 1Program in International and Community Nutrition,Department of Nutrition,University of California,Davis,One Shields Avenue,Davis,CA 95616,USA.
authors.forename: Rebecca R
authors.initials: RR
authors.lastname: Young
authors.affiliation: 2Helen Keller International,Niamey,Niger.
authors.forename: Ibrahim F
authors.initials: IF
authors.lastname: Bamba
authors.affiliation: 3Laboratory of Human Nutrition,Swiss Federal Institute of Technology,Zurich,Switzerland.
authors.forename: Sara
authors.initials: S
authors.lastname: Stinca
authors.affiliation: 3Laboratory of Human Nutrition,Swiss Federal Institute of Technology,Zurich,Switzerland.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Zimmermann
authors.affiliation: 1Program in International and Community Nutrition,Department of Nutrition,University of California,Davis,One Shields Avenue,Davis,CA 95616,USA.
authors.forename: K Ryan
authors.initials: KR
authors.lastname: Wessells
mesh_terms: D000328:Adult; D002648:Child; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D059788:Dried Blood Spot Testing; D005191:Family Characteristics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007455:Iodine / Q000008:administration & dosage / Q000172:deficiency* / Q000652:urine*; D008297:Male; D009548:Niger / Q000453:epidemiology; D009752:Nutritional Status; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000453:epidemiology*; D015995:Prevalence; D012424:Rural Population; D018401:Sample Size; D012959:Socioeconomic Factors; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage / Q000652:urine; D013954:Thyroglobulin / Q000097:blood; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D055815:Young Adult
chemical_list: D017673:Sodium Chloride, Dietary; C034024:iodized salt; D013972:Thyrotropin; D013954:Thyroglobulin; D007455:Iodine; D013974:Thyroxine
keywords: Iodine; Niger; Pregnant women; School-aged children; Thyroglobulin; Urinary iodine