title: Assessment of iodine status in children, adults, pregnant women and lactating women in iodine-replete areas of China.
abstract: BACKGROUND
  Iodine deficiency disorders (IDD) are widespread in China. Presently, IDD have been put under control by Universal Salt Iodisation (USI) in China; however, there is a lack of evidence on whether the iodine status in adults, pregnant women and lactating women is optimal. This study was therefore conducted to assess the iodine nutrition and thyroid function of children, adults, pregnant women and lactating women residing in areas where the USI program is fully established.
  
  
  METHODS
  Six areas were selected according to the geographical regions in China. In each of these areas, we selected 4 distinct groups of subjects (children, adults, pregnant women and lactating women) in regions where the coverage rate of iodised salt was more than 95% and the levels of iodine and fluoride in drinking water were less than or equal to 10 µg/L and 1 mg/L, respectively. We tested the iodine content of salt, urinary iodine (UI), free thyroxin (FT4), thyrotropin (TSH), thyroglobulin (Tg), thyroglobulin antibody (Tg-Ab) and antimicrosomal antibody (TM-Ab) in the 4 groups, and examined the thyroid volume in children.
  
  
  RESULTS
  The median urinary iodine (MUI) concentrations were 271.4 μg/L, 260.2 μg/L, 205.9 μg/L and 193.9 μg/L in children, adults, pregnant women and lactating women, respectively; MUI in children and adults were more than adequate. The goitre prevalence (GP) in children was 6.70%. The odds ratios (OR) of subclinical hypothyroidism in the Tg-Ab- or TM-Ab-positive groups were 3.80, 7.65, 2.01 and 7.47 for children, adults, pregnant women and lactating women, respectively, compared with the negative groups.
  
  
  CONCLUSIONS
  The iodine status in children and adults is above the requirement, we should reduce their iodine intake. Subclinical hypothyroidism easily occurs in the Tg-Ab or TM-Ab positive groups.
authors.affiliation: Institute of Iodine Deficiency Disorders, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China.
authors.forename: Fangang
authors.initials: F
authors.lastname: Meng
authors.forename: Rencheng
authors.initials: R
authors.lastname: Zhao
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.forename: Lixiang
authors.initials: L
authors.lastname: Liu
authors.forename: Shoujun
authors.initials: S
authors.lastname: Liu
mesh_terms: D000328:Adult; D002648:Child; D002681:China / Q000453:epidemiology; D003677:Deficiency Diseases / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007455:Iodine / Q000008:administration & dosage / Q000172:deficiency* / Q000652:urine; D007774:Lactation; D011247:Pregnancy; D013954:Thyroglobulin / Q000097:blood; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
chemical_list: D013972:Thyrotropin; D013954:Thyroglobulin; D007455:Iodine; D013974:Thyroxine