title: Lebanese children are iodine deficient and urinary sodium and fluoride excretion are weak positive predictors of urinary iodine.
abstract: OBJECTIVE
  To assess iodine and fluoride status among Lebanese children.
  
  
  METHODS
  A nationally representative cross-sectional study of 6- to 10-year-old schoolchildren was conducted using multistage cluster sampling. Spot urine samples were collected from 1403 children, and urinary iodine, fluoride, creatinine and sodium levels were measured. Salt samples from markets (n = 30) were tested for iodine concentration by titration.
  
  
  RESULTS
  Median urinary iodine concentration was 66.0 µg/l, indicating mild deficiency, and almost 75 % of Lebanese children had a urinary iodine concentration (UIC) <100 µg/l. UIC was higher among children from private schools and in areas of higher socioeconomic status. Most salt samples were fortified at levels far below the legislated requirement, and 56 % of samples contained less than 15 ppm iodine. Fluoride-to-creatinine ratio (F/Cr) was 0.250 (0.159-0.448) mg/g. There were weak positive correlations between UIC and urinary sodium (r2= 0.039, P value <0.001) and UIC and urinary fluoride (r2= 0.009, P value <0.001).
  
  
  CONCLUSIONS
  Lebanese elementary school children are iodine deficient due to inadequately iodized salt. The weak correlation between UIC and urinary sodium suggests most dietary iodine does not come from iodized salt. The poor correlation between UIC and urinary fluoride suggests that fluoride intake is not affecting iodine metabolism. Efforts are needed in Lebanon to improve industry compliance with salt fortification through improved monitoring and enforcement of legislation.
authors.affiliation: Faculty of Health Sciences, Center for Research on Population and Health, American University of Beirut, Beirut, Lebanon.
authors.forename: Hala
authors.initials: H
authors.lastname: Ghattas
authors.affiliation: Department of Nutrition and Food Science, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon.
authors.forename: Sirine
authors.initials: S
authors.lastname: Francis
authors.affiliation: Department of Nutrition and Food Science, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon.
authors.forename: Carla
authors.initials: C
authors.lastname: El Mallah
authors.affiliation: Department of Nutrition and Food Science, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon.
authors.forename: Dareen
authors.initials: D
authors.lastname: Shatila
authors.affiliation: Department of Nutrition and Food Science, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon.
authors.forename: Karina
authors.initials: K
authors.lastname: Merhi
authors.affiliation: Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
authors.forename: Sani
authors.initials: S
authors.lastname: Hlais
authors.affiliation: Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Zimmermann
authors.affiliation: Department of Nutrition and Food Science, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon. omar.obeid@aub.edu.lb.
authors.forename: Omar
authors.initials: O
authors.lastname: Obeid
mesh_terms: D015415:Biomarkers / Q000652:urine; D002648:Child; D002664:Child Nutritional Physiological Phenomena / Q000208:ethnology; D003404:Creatinine / Q000652:urine; D003430:Cross-Sectional Studies; D003677:Deficiency Diseases / Q000208:ethnology / Q000503:physiopathology / Q000652:urine*; D005260:Female; D005461:Fluorine / Q000652:urine*; D005527:Food, Fortified / Q000032:analysis / Q000191:economics / Q000592:standards; D019983:Guideline Adherence; D006801:Humans; D007455:Iodine / Q000032:analysis / Q000737:chemistry / Q000172:deficiency* / Q000191:economics / Q000592:standards / Q000652:urine; D007861:Lebanon; D007881:Legislation, Food; D008297:Male; D018673:Nutrition Policy / Q000331:legislation & jurisprudence; D009752:Nutritional Status / Q000208:ethnology; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D012964:Sodium / Q000652:urine*; D017673:Sodium Chloride, Dietary / Q000032:analysis / Q000191:economics / Q000592:standards
chemical_list: D015415:Biomarkers; D017673:Sodium Chloride, Dietary; C034024:iodized salt; D005461:Fluorine; D007455:Iodine; D012964:Sodium; D003404:Creatinine
keywords: Fluoride/creatinine ratio; Iodine/creatinine ratio; Lebanon; Sodium/creatinine ratio; Urinary fluoride; Urinary iodine excretion