title: A cross-sectional survey of urinary iodine status in Latvia.
abstract: OBJECTIVE
  A nationwide survey of schoolchildren was conducted to detect regional differences in urinary iodine excretion in Latvia and to compare the results with data from the newborn thyroid-stimulating hormone (TSH) screening database as well with the results of a similar study performed in Latvia 10 years ago.
  
  
  METHODS
  We conducted a cross-sectional school-based cluster survey of 915 children aged 9-12 years in 46 randomly selected schools in all regions of Latvia. Urine samples, questionnaires on the consumption of iodized salt and information on socioeconomic status were collected. TSH levels in newborns were also measured.
  
  
  RESULTS
  The median creatinine-standardized urinary iodine concentration (UIC) in our study was 107.3μg/g Cr. UIC measurements indicative of mild iodine deficiency were present in 31.6%, moderate deficiency in 11.9% and severe deficiency in 2.8% of the participants. The prevalence of iodine deficiency was the highest in the southeastern region of Latgale and the northeastern region of Vidzeme. The prevalence of TSH values >5mIU/L followed a similar pattern. The self-reported prevalence of regular iodized salt consumption was 10.2%. Children from urban schools had a significantly lower UIC than children from rural schools.
  
  
  CONCLUSIONS
  Our findings suggest that although the overall median UIC in Latvian schoolchildren falls within the lower normal range, almost 50% of the schoolchildren are iodine deficient, especially in urban schools and in the eastern part of Latvia. The absence of a mandatory salt iodization program puts a significant number of children and pregnant women at risk.
authors.affiliation: Riga Stradins University, Riga, Latvia; Department of Medicine, Riga East Clinical University Hospital, Riga, Latvia. Electronic address: drkonrade@inbox.lv.
authors.forename: Ilze
authors.initials: I
authors.lastname: Konrade
authors.affiliation: Riga Stradins University, Riga, Latvia.
authors.forename: Lolita
authors.initials: L
authors.lastname: Neimane
authors.affiliation: Riga Stradins University, Riga, Latvia; Latvian Institute of Organic Synthesis, Riga, Latvia.
authors.forename: Marina
authors.initials: M
authors.lastname: Makrecka
authors.affiliation: Riga Stradins University, Riga, Latvia.
authors.forename: Ieva
authors.initials: I
authors.lastname: Strele
authors.affiliation: Latvian Institute of Organic Synthesis, Riga, Latvia.
authors.forename: Edgars
authors.initials: E
authors.lastname: Liepinsh
authors.affiliation: Riga Stradins University, Riga, Latvia; Department of Medicine, Riga East Clinical University Hospital, Riga, Latvia.
authors.forename: Aivars
authors.initials: A
authors.lastname: Lejnieks
authors.affiliation: Clinic of Medical Genetics, Children's University Hospital, Riga, Latvia.
authors.forename: Parsla
authors.initials: P
authors.lastname: Vevere
authors.affiliation: Department of Medicine, University of Texas, Southwestern Medical Center and North Texas Veterans Affairs Medical Center, Dallas, TX, USA.
authors.forename: Ugis
authors.initials: U
authors.lastname: Gruntmanis
authors.affiliation: Department of Medicine, University of Latvia, Riga, Latvia; Pauls Stradins Clinical University Hospital, Riga, Latvia.
authors.forename: Valdis
authors.initials: V
authors.lastname: Pīrāgs
authors.affiliation: Riga Stradins University, Riga, Latvia; Latvian Institute of Organic Synthesis, Riga, Latvia.
authors.forename: Maija
authors.initials: M
authors.lastname: Dambrova
mesh_terms: D002648:Child; D003404:Creatinine / Q000652:urine; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007455:Iodine / Q000008:administration & dosage / Q000172:deficiency* / Q000652:urine*; D007844:Latvia / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D057566:Self Report; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage / Q000652:urine*; D013972:Thyrotropin / Q000097:blood
chemical_list: D017673:Sodium Chloride, Dietary; C034024:iodized salt; D013972:Thyrotropin; D007455:Iodine; D003404:Creatinine
keywords: Deficiency; Iodine; Iodized salt; Thyroid stimulating hormone