Iodine nutrition and thyroid function in iodized salt supplied regions / 中华地方病学杂志

ABSTRACT

Objective To study the effect of different iodine nutrition on thyroid function in adult and pregnant women.Methods A random sampling method was used to select healthy adult and pregnant woman from the communities of coastal city,coastal rural and inland rural areas in Liaoning Province.Drinking water,urine and salt samples were collected to measured urinary iodine (U I),salt iodine (SI) and water iodine content.Fasting venous blood was collected to measured thyroid stimulate hormone (TSH),freethyroxine (FT4),free triiodothyronine (FT3),thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) with the method of immunoassay chemical luminescence.Results A total of 150 salt samples were collected,means of SI was (30.1 ± 6.0)mg/kg.A total of 72 pregnant woman and 271 adults were investigated in iodized salt supplied regions.median UI of pregnant woman and adults were 176.3,203.2 μg/L.Iodine nutrition of pregnant women and coastal region adults was in an adequate level.Means of SI of inland adults(244.4 μg/L) was higher than appropriate level but not reached the excessive level.FT4 of the adults (11.7 pmol/L) and pregnant women (10.7 pmol/L) in inland regions were slightly higher than that of coastal city,rural adults(11.2,8.6 pmol/L) and pregnant women (10.9,9.6 pmol/L).TSH,FT3 and FT4 were not statistically different between regions (all P ＜ 0.05).But UI,FT4 and FT3 levels of pregnant women(176.3 μg/L,9.5 pmol/L,4.3 pmol/L) were significantly lower than that of the adults(203.2 pμg/L,11.3 pmol/L,4.7 pmol/L,all P ＜ 0.05).Hypothyroxinemia(4.4％,10/173) was higher than that of the inland adults (2.0％,2/98,P ＜ 0.05).And all hypothyroxinemia were found in women of childbearing age.Hypothyroxinemia prevalence of pregnant women(16.7％,12/72) was higher than that of adults(4.4％,12/271,P ＜ 0.05),The prevalence of hypothyroidism,hyperthyroidism and subclinical hyperthyroidism between the 3 regions adults and pregnant women were not statistically different (all P ＞ 0.05).Conclusions Under appropriate supply conditions of iodized salt,iodine nutrition and thyroid function are closely related.Pregnant women and women of childbearing age are at risk of iodine deficiency.The thyroid function of these people should be strengthen detect.