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Objective:To evaluate the current situation of prevention and control of iodine deficiency disorders (IDD), and to describe the iodine nutrition level of pregnant women in key population in Zhejiang Province.Methods:In 2021, a cross-sectional survey on iodine nutrition status of the population was conducted in all 90 counties (cities, districts) in Zhejiang Province. Each county (city, district) was divided into five districts: east, west, south, north, and central. One township (street) was selected from each district, and 20 pregnant women were selected from each township (street) to collect edible salt samples and one random urine sample for salt and urinary iodine testing. The above indicators were stratified and analyzed according to urban, rural, coastal, inland, early pregnancy, mid pregnancy, and late pregnancy.Results:A total of 9 679 pregnant women's salt samples were tested, with a salt iodine content of (20.2 ± 9.2) mg/kg, an iodized salt coverage rate of 84.2% (8 153/9 679), and a qualified iodized salt consumption rate of 80.4% (7 785/9 679). Among them, the qualified iodized salt consumption rate of pregnant women in coastal areas was 69.4% (3 175/4 575), significantly lower than that in inland areas [90.3% (4 610/5 104)]; and the proportion of non iodized salt consumption in coastal areas [25.8% (1 181/4 575)] was significantly higher than inland areas [6.8% (345/5 104)]. A total of 9 679 pregnant women's urine samples were tested, with a median urinary iodine of 133.0 μg/L ( < 150 μg/L). In urban areas, the median urinary iodine (129.8 μg/L) was lower than that in rural areas (135.0 μg/L). Likewise, the median urinary iodine was 126.0 μg/L, lower than inland areas (140.3 μg/L). And as pregnancy progressed, the iodine nutrition level of pregnant women gradually decreased (the median urinary iodine: 137.0 μg/L in early pregnancy, 134.1 μg/L in mid pregnancy, and 129.4 μg/L in late pregnancy).Conclusion:In 2021, pregnant women in Zhejiang Province are in a state of iodine deficiency, and there is a greater risk in urban areas compared to rural areas and coastal areas compared to inland areas.
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Objective@#To investigate the status of iodine nutrition and prevalence of goiter among children at ages of 8 to 10 years in Zhejiang Province in 2021, so as to provide insights into the management of iodine deficiency in children.@*Methods @#A total of 90 counties (districts) were sampled as field survey sites from 11 cities of Zhejiang Province using a multi-stage stratified random sampling method in 2021, and non-residential children at ages of 8 to 10 years in these sites were sampled as study subjects. Subjects' household edible salt samples and random urine samples were collected. The iodine content in salt and urinary iodine level were determined using the direct titration method and arsenic-cerium catalytic spectrophotometry for evaluation of iodine nutrition among children. In addition, the lateral lobe of the thyroid gland was measured using ultrasound, and the prevalence of goiter was estimated. @*Results@#A total of 19 363 children were recruited, including 9 710 male children and 9 653 female children, with a male to female ratio of 1.01︰1, and there were 10 704 urban children (55.28%) and 8 659 rural children (44.72%), 9 149 children living in coastal areas (47.25%) and 10 214 children in inland regions (52.75%). The mean iodine content was (19.79±9.25) mg/kg in salt, and the coverage of qualified iodized salt (15 252) was 78.77%. The coverage of qualified iodized salt was significantly lower in urban children than in rural children (76.70% vs. 81.21%; χ2=68.301, P<0.001), and was lower in children living in coastal regions than in inland regions (68.05% vs. 88.27%; χ2=1 270.769, P<0.001). The median urinary iodine concentration was 195.1 μg/L, and the household iodine content in salt correlated positively with urinary iodine concentration in children (rs=0.383, P<0.001). There were 2 885 children with iodine deficiency (14.90%), 7 137 children with adequate iodine (36.86%), 5 414 children with excessive iodine intake (27.96%), and 3 927 children with iodine overdose (20.28%), and the distribution of iodine nutrition in children varied significantly in regions (χ2=283.277, P<0.001) and gender (χ2=126.349, P<0.001). The prevalence of goiter was 2.45% among 7 195 children receiving ultrasound examinations, and a higher prevalence rate of goiter was detected in urban children than in rural children (2.76% vs. 2.00%; χ2=3.962, P=0.047). @*Conclusions @#The overall urinary iodine nutrition was adequate among children at ages of 8 to 10 years in Zhejiang Province in 2021, and the prevalence of goiter in children fell within the threshold defined in the criteria of elimination of iodine deficiency. However, the supervision of the iodized salt quality remains to be improved and iodine deficiency control remains to be reinforced.
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Objective To set up the reference ranges of thyroid hormones for pregnant and lactating woman in Zhejiang.Methods A total of 338 pregnancy,322 lactating women and 139 non-pregnant women (as a control) were selected from 1 079 women in 13 survey sites of Zhejiang as survey subjects,through the questionnaire survey and thyroid B-ultrasound tests from June 2010 to September 2010.The level of urinary iodine was measured by spectrophotometer,and the thyroid hormone [free triiodothyronine (FT3),free (unbound) thyroxin (FT4),triiodothyronine (T3),tetraiodothyronine (T4),thyroid stimulating hormone (TSH)] was measured by automated chemiluminescence immunoassay.Analysis of thyroid hormone 95％ in pregnant women and lactating women.Results The median urinary iodine of all women investigated were in optimal urine levels (150-249 μg/L),which indicated they were in iodine sufficient status.The FT3 index of lactating women was higher than that of pregnant women and non pregnant women (Zlactating-pregnant =3.98,Zlactating-pregnant =2.46,all P ＜ 0.05);the FT4 index level of lactating women was higher than that of pregnant women and non pregnant women (Zlactating-pregnant =2.68,Zlactating-non-pregnant =2.25,all P ＜ 0.05);the T3 index level of lactating women was higher than that of pregnant women and non pregnant women (Zlactating-pregnant =3.51,Zlactating-non pregnant =2.41,all P ＜ 0.05);levels of T4 in lactating women was the highest (Zlactating-pregnant =2.30,Zlactating-pregnant =4.90,Zlactating-non pregnant =1.57,all P ＜ 0.05);TSH index of lactating women and non pregnant women were higher than that of pregnant women (Zlactating-pregnant =2.81,Zlactating-non pregnant =1.68,all P ＜ 0.05).And in pregnant,the 95％ medical reference interval of FT3 was 3.37-6.53 pmol/L,FT4 was 10.68-20.85 pmol/L,T3 was 1.40-2.79 nmol/L,T4 was 72.72-166.41 nmol/L,and TSH was 0.15-4.44 mU/L;in lactating woman,FT3 was 3.39-6.44 pmol/L,FT4 was 10.81-20.33 pmol/L,T3 was 1.44-2.77 nmol/L,T4 was 71.94-164.61 nmol/L,and TSH was 0.25-4.47 mU/L.Conclusion The thyroid hormone levels of pregnant and lactating women are different from those of non-pregnant women,therefore establishing reference data of thyroid hormones for pregnant and lactating women may be a very important step for clinical practice.
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Objective To find out the status of iodine nutrition and the goiter of population in Zhejiang Province after adjustment of salt iodine concentration.Methods From April to June 2013,the probability proportionate to size sampling method was applied in 31 countries in Zhejiang Province to select 1 650 school-age children aged 8-10 to examine thyroid by B ultrasound,to collect urine and salt samples,and to test the iodine level using the colorimetric titration method and the spectrophotometer method.Six hundred and twenty pregnant women were selected to collect urine samples and urinary iodine was tested by the spectrophotometer method.Results The coverage rate of iodized salt and the consumption rate of qualified iodized salt in Zhejiang Province after adjustment of salt iodine concentration were 93.20％ (1 521/1 632) and 89.71％ (1 464/1 632),respectively;and the medians urinary iodine in children and pregnant women were 178.40 μg/L and 127.23 μg/L,respectively;and the goiter and median thyroid volume were 5.27％ (87/1 650) and 3.45 ml,respectively;the P97 thyroid volume of children in Zhejiang Province in the 8,9 and 10 years old groups (4.76,5.29,6.36 ml) were higher than those (4.5,5.0,6.0 ml) in the thyroid volume reference (WS 276-2007);and the correlations between thyroid volume,goiter and urinary iodine were not found.Conclusions After adjustment of salt iodine concentration,the status of iodine nutrition in Zhejiang Province in general is down to optimum level,which indicates that it is appropriate for this adjustment,but the level of iodine nutrition in pregnant women is less than appropriate,which should be pay attention to.