Prevalence and risk factors of thyroid structural abnormalities among adults in Heilongjiang Province, China

The prevalence of adult thyroid structural abnormalities has increased significantly worldwide. However, no study has examined the thyroid structure and urine iodine levels of adults in Heilongjiang Province in the last decade. Therefore, this study aims to investigate the rate and risk factors of thyroid structural abnormalities among the residents of this province. A probability proportional sampling method was used, and a total of 3,645 individuals in Heilongjiang Province were included. The subjects was asked to complete a thyroid ultrasound and fill out a questionnaire. Furthermore, urine iodine levels and salt iodine content were determined, and multivariate logistic regression was used to identify the independent risk factors for thyroid diseases. The prevalence of thyroid structural abnormalities in Heilongjiang Province was 56.0%. Univariate analysis showed that there were significant differences between the structural abnormalities group and the normal thyroid group in terms of sex, age, body mass index, hypertension, diabetes, smoking, alcohol consumption, frequency of seafood consumption and pickled food consumption, employment status, and urine iodine level (p<0.05). Multivariate analysis showed that the following were independent risk factors of thyroid disease: female, increased age, hypertension, diabetes, cigarette smoking frequent seafood consumption, employment, and urine iodine levels. The prevalence of thyroid structural abnormalities in adults in Heilongjiang Province was relatively high. Therefore, to help prevent the occurrence of thyroid disease in adults in Heilongjiang Province, the risk factors of thyroid structural abnormalities should be better understood.

Objective To investigate the distribution of urinary iodine level and its relationship with thyroid function in Tibetan adults in Lhasa. Methods Tibetan residents living in Lhasa and its surrounding countryside were recruited by the method of multistage randomized cluster sampling. Their salt iodine, drinking water iodine, urinary iodine, and thyroid function levels were detected. According to the urinary iodine level, these subjects were divided into the iodine deficiency group (urinary iodine<100 μg/L), the iodine enough group (urine iodine 100-199 μg/L), the iodine adequate group (urine iodine 200-299 μg/L) and the iodine excessive group (urine iodine≥300 μg/L). The differences in thyroid function among various groups were compared. Results A total of 2 235 subjects were included in the study. The overall level of urinary iodine was in skewed distribution, with a median (upper and lower quartiles) of 154 (99, 229) μg/L. The proportion of subjects with insufficient iodine intake was 25.7%, while those of the enough, adequate, and excessive groups were 41.5%, 21.3%, and 11.5%, respectively. There was no significant difference in urine iodine level between males and females [152(95, 219)μg/L vs 155(100, 232)μg/L P>0.05]. The urinary iodine levels in residents of urban were higher than those in rural residents [157(101, 232) μg/L vs 140(92, 200) μg/L, P 0.05). The levels of thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) were gradually decreased with the increase of urinary iodine level (P<0.05). Conclusion More than 50% of Tibetans are at the status of low iodine and high iodine intakes in Lhasa. Although the salt iodine content meets national standards, the drinking water iodine content is lower than that standard. Key words: Lhasa; Tibetan; Urinary iodine; Thyroid function

Objective To investigate the relationship between urinary iodine level and thyroid disease.Methods The study used a case-control design.One hundred and nine patients with thyroid disease from the Affiliated Hospital of Shanxi Institute for Endemic Disease Control were selected as case group from 2011 to 2012,and these patients were divided into three groups:Graves's disease (GD) group (n =48),chronic lymphocytic thyroiditis (HT) group(n =34) and thyroid nodules group(n =27).Sixty-two healthy people from the same region were selected as a control group.Urinary iodine was determined using arsenic cerium catalytic spectrophotometry,thyroid autoantibody (TRAb) and thyroid peroxidase antibody (TPOAb) was detected using electrochemiluminescence,while iodine absorption rate was measured using thyroid function analyzer,and thyroid volume was measured using type-B ultrasonic method.The relationship between urinary iodine level and patients with thyroid disease was compared with that of control group.Results Urinary iodine levels of patients with GD,HT,thyroid nodules and control groups were 313.95,375.20,220.20 and 196.50 μg/L,respectively.Urinary iodine levels of patients with GD and HT groups were higher than that of control group(Z =3.238,4.275,all P ＜ 0.0125).Urinary iodine level of patients with HT was higher than that of thyroid nodules(Z =3.762,P ＜ 0.0125).Iodine uptakes of GD,HT,thyroid nodules and control groups were (84.20 ± 16.90)％,(23.51 ± 6.72)％,(28.34 ± 8.02)％ and (29.31 ± 8.41)％; TRAbs of patients with GD,HT,thyroid nodules and control groups were (58.57 ± 20.31)％,(2.54± 1.00)％,(2.98 ± 0.83)％ and (3.01 ± 1.21)％; TPOAbs of patients with GD,HT,thyroid nodules and control groups were (117.03 ± 57.21)％,(251.00 ± 98.20)％,(16.81 ± 9.87)％ and (15.00 ± 7.23)％.Iodine uptake,TRAb and TPOAb of GD group were higher than those of control group(P ＜ 0.05).TPOAb of HT group was higher than that of control group(P ＜ 0.05).Urinary iodine levels of GD group and HT group were positively correlated with TPOAb(correlation coefficient were 0.462,0.478 all P ＜ 0.05).Conclusions Excessive iodine intake is found in patients with GD and HT.Determination of urinary iodine is helpful for individualized iodine supplementation. Key words: Urine; Iodine; Graves' disease ; Chronic lymphocytic thyriuditis

Objective To analyze the urinary iodine status of urban and rural residents in some areas of Gansu Province and its related influencing factors, and to provide certain references for scientific iodine intake of urban and rural residents in Gansu Province. Methods Subjects in Gansu Province with normal thyroid function were recruited in the investigation of thyroid diseases and iodine nutritional status, conducted a questionnaire survey and measured height, weight, waist circumference, collected 1 urine sample, and tested their urinary iodine levels. The urinary iodine levels of different groups were compared based on different gender, region, age, body weight, the waist, and salt intaking. The affecting factors of urinary iodine levels were analyzed by multiple linear regression models. Results Totally 1 964 subjects were recruited, including 1 099 males, and 865 females. The age was (41.23 ± 14.75) years old. The median urinary iodine of the selected group was 225.60 (158.80, 311.58) μg/L. The urinary iodine level of rural residents was significantly higher than that of urban residents [μg/L: 249.80 (180.58, 336.88) vs 206.25 (148.03, 280.33), Z=-8.015, P 0.05]. The composition ratio of < 100 μg/L group in rural areas was lower than that in urban areas (5.14% vs 8.27%, χ2= 7.45, P < 0.05), and the composition ratio of ≥300 μg/L group was higher than that in urban areas (34.93% vs 21.51%, χ2= 43.87, P < 0.05). The composition ratio of ≥300 μg/L group in male was lower than that in female (24.57% vs 31.21%, χ2= 10.73, P < 0.05). The multiple linear regression analysis showed that lived in rural areas, age, moderate and severe salt intaking, student, and weight were independently correlated with urinary iodine levels (β= 0.074, -0.001, 0.059, 0.034, 0.096, -0.003, P < 0.05). And the urinary iodine levels were decreased with age and weight increased (P < 0.05). Conclusions At present, the iodine nutrition level of urban and rural residents in some areas of Gansu Province is generally over the adequate level. The urinary iodine level of rural residents is higher than that of urban residents. In the future, we should pay attention to the impact of different living areas, salt intaking and body weight on urinary iodine levels to prevent thyroid diseases. Key words: Urine; Iodine; Urban; Rural; Iodine status; Affecting factors

Objective To investigate the relationship between iodine nutritional status and thyroid hormone levels, and to provide a guideline for monitoring iodine nutrition and thyroid function. Methods A cross-sectional survey was performed by randomly selecting 341 samples (health pregnant women with a first child) from the Second People's Hospital of Guiyang, Bihai Community Medical Center and Jinhuayuan Community Center from October 2015 to September 2016. Levels of serum hormones and antibodies relative to throid of pregnant women in Guanshan LakeDistrict of Guiyang at different pregnant times, which included throid stimulating hormone (TSH), free three triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb), were measured by the electrochemical luminescence method, and urinary iodine levels were measured by heat digestion. Results The median urinary iodine of pregnant women at early, middle and late stages (T1, T2 and T3 stages) were 191.8, 198.9 and 214.5 μg/L, respectively. FT3 increased first and then decreased during pregnancy. Levels of FT3 in the T2 stage were significantly higher than those in T1 and T3 stages (FT3 medians at the three stages were 4.49, 4.83 and 4.57 pmol/L), and the differences were statistically significant (P 0.05). The medians of TPOAb and TgAb during T2 stage (9.60 and 19.02 U/ml) were significantly lower than those of other groups (18.92 and 24.75 U/ml at stage T1, and 13.46 and 22.06 U/ml at stage T3), and the differences were statistically significant (P < 0.05). TSH levels were consistent with urinary iodine levels. TSH levels in the excessive iodine group (urine iodine: 250~ 499 μg/L, 2.54 mU/L) were significantly higher than those in the adequate iodine group (urine iodine: 150~ 249 μg/L, 1.97 mU/L) and deficient iodine group (urine iodine: < 150 μg/L, 1.91 mU/L), and the differences were statistically significant (P < 0.05). No correlations were found between levels of FT3, FT4, TPOAb, TgAb and levels of the urinary iodine. There was a significant positive correlation between urinary iodine levels and TSH levels (rs= 0.180, P < 0.01). The incidence of abnormal thyroid function in pregnant women was 29.33% (100/341), which was composed of clinical hypothyroidism (accounting for 0.88%, 3/341), subclinical hypothyroidism (accounting for 25.51%, 87/341), low T4 level (accounting for 1.76%, 6/341), clinical hyperthyroidism (accounting for 0.59%, 2/341), subclinical hyperthyroidism (accounting for 0.59%, 2/341), and TPOAb positive and TgAb positive (accounting for 12.61%, 43/341). These abnormalities occurred mainly in the T1 and T3 stages. The prevalence of subclinical hypothyroidism increased with increasing of urinary iodine level, and the difference was statistically significant (χ2= 11.269, P < 0.05). Conclusion There is a positive correlation between pregnancy iodine nutritional status and its TSH level, so it is important to monitor the level of urinary iodine during pregnancy and to screen the thyroid function and antibodies in the early and middle time of pregnancy. Key words: Pregnancy; Iodine nutrition; Thyroid hormone

To analyze the change of urinary iodine in a cohort of intervention trial and to observe the role of different doses on salt iodization and related impact factors on nutritional condition of iodine. Multistage cluster sampling was used to sample three townships in two counties for community intervention with different doses (15 ± 5, 25 ± 5, 35 ± 5) mg/kg. Compared to the (35 ± 5) mg/kg group, the urine iodine levels of three experimental townships were gradually declining in county B when time went on, and the (15 ± 5) mg/kg group showed an obvious results, at 6, 12, 18 and 24 months, with the urine iodine level as 180.00, 186.10, 150.04, 191.28 µg/L respectively, which were in accordance with the WHO standard and reached to appropriate range (187.96 µg/L) at the 18 month. The townships at county Y under intervention had declined slightly, but the urine iodine levels did not reach the WHO standard. The thyroid volume declined from 3.65 ml to 3.40 ml in two counties and the difference between them was statistically significant. To some extent, reducing the iodine concentration in salt, had a role of lowering the urine iodine level and reducing the strumous rate.

Objective To understand the iodine nutritional status of population and the progress of eliminating iodine deficiency disorders after the adjustment of iodine content of edible salt in Fujian Province. Methods Thirty counties were sampled by population proportion probability sampling in the whole province. The iodine level in edible salt from 1 507 households was tested by direct titration method (GB/T 13025.7-1999); goiter rate and prevalence of thyroid nodules of 1 642 children aged 8 - 10 were examined by type-B ultrasound; urinary iodine level of 1 619 children and 623 pregnant women was determined by arsenic cerium catalytic spectrophotometric method (WS/T 107-2006). Results The median of iodine level in edible salt from those 1 507 households was 24.3 mg/kg, the consumption rate of qualified iodized salt was 92.0% (1 387/1 507); the goiter rate of those 1 642 children aged 8 - 10 was 3.1% (51/1 642), their prevalence of thyroid nodules was 14.4% (236/1 642), and the median urinary iodine level was 154.3 μg/L, among them, urinary iodine 0.05, those children aged 8 - 10 were divided into several groups base on the median urinary iodine level ( 0.05]. Conclusions All indicators have met the national standard of eliminating iodine deficiency disorders after the adjustment of iodine content of edible salt in Fujian Province. Iodine content of edible salt has been adjusted in place, in the general population, iodine nutritional level is in suitable condition. There exists no problem of iodine excess, but there is an iodine deficiency problem in pregnant women, among those children aged 8 - 10, the prevalence of thyroid nodules has nothing to do with the iodine nutritional level. Key words: Salts; Deficiency diseases, iodine; Urine; Thyroid nodule

Objective To study the urinary iodine level of pregnant women with thyroid disease in Shenzhen, and to provide scientific basis for rational iodine supplementation. Methods A total of 170 pregnant women with thyroid diseases who visited Department of Endocrinology, Peking University Shenzhen Hospital from January 2017 to March 2019 were selected as the subjects, they were divided into hyperthyroidism group (84 cases) and non-hyperthyroidism group (86 cases) according to whether they had hyperthyroidism or not. Morning urine sample was collected under normal dietary conditions; urinary iodine was detected by peroxyacetic acid tetramethylbenzidine oxidation colorimetry. Urinary iodine < 150 μg/L was iodine deficiency and 150-249 μg/L was appropriate iodine. Results The median of urinary iodine of pregnant women with thyroid disease in Shenzhen was 143.9 μg/L, which was slightly lower than the lowest limit of the appropriate iodine level. The median of urinary iodine in hyperthyroidism group was 116.6 μg/L, which was at the iodine deficiency level; the median of urinary iodine in non-hyperthyroidism group was 181.6 μg/L, which was at the appropriate iodine level. There was significant difference in urinary iodine levels between hyperthyroidism group and non-hyperthyroidism group (Z =-2.261, P < 0.05). Conclusion The urinary iodine of pregnant women with hyperthyroidism in Shenzhen is slightly low. Key words: Thyroid diseases; Pregnancy complications; Urine; Iodine

Objective To investigate the correlation between iodine nutritional status and thyroid diseases in some areas of Ningxia. Methods The physical examination, questionnaire survey, and measurement of urine iodine, thyroid function, thyroid associated antibodies were performed, with thyroid ultrasonography in Jingyuan County, Xingqing District and Guyuan City, Ningxia Yinchuan City, totally including 2 827 adults. Results The median urinary iodine of all subjects was 258.7(76.6-1 506.4) μg/L. The average level of urinary iodine in rural areas[203.3(64.6-1 154)μg/L] was lower than that in cities[340.7(114.8-1 726.1)μg/L, Z=19.514, P 0.05). If compared with single nodule, multiple nodules group and the normal group′s median levels of urinary iodine also had no significant difference(P>0.05). Conclusion Iodine excess was found in the studied population in these areas of Ningxia. (Chin J Endocrinol Metab, 2018, 34: 394-397) Key words: Urinary iodine; Thyroid function; Thyroid nodule

Objective To explore the iodine nutrition and medical reference range of serum iodine in adults of normal thyroid function, and to provide scientific evidence for individual iodine nutritional assessment. Methods Totally 244 postgraduate freshmen were selected in one university, which is located in Harbin, Heilongjiang Province. Adults of normal thyroid function were recruited, excluding the adults of abnormal thyroid function and other diseases. The following indicators were adopted to assess iodine status: arsenic cerium catalytic spectrophotometry (WS/T 107.1-2016) was used to detect urinary iodine, perchloric acid and sodium cholrate resolution method was used to detect serum iodine, chemiluminescence immune assay was used to detect free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), thyroglobulin antibody (TGAb), thyroid peroxidase antibody (TPOAb). To assess these indicators and conduct correlation analysis. Results A total of 185 adults with normal thyroid function were chosen, the level of urinary iodine [M (P25, P75)] was 140.40 (90.30, 198.95) μg/L. The average level of serum iodine was (66.32 ± 15.46) μg/L for the adults of normal thyroid function, the 95% medical reference range of serum iodine in normal adults was initially formulated as 36.02-96.62 μg/L. The average level of FT3 in adults of normal thyroid function was (5.18 ± 0.51) pmol/L, the average level of FT4 was (18.04 ± 2.06) pmol/L, and the level of TSH was 1.57 (1.14, 2.04) mU/L. The area under the receiver operating characteristic (ROC) curve for serum iodine was 0.781, it was higher than the area under ROC curve for urinary iodine (0.524), the difference was statistically significant (t =-12.22, P 0.05). Conclusions Serum iodine, which can accurately reflect recent iodine nutritional status, is relatively stable than urinary iodine. The medical reference range of serum iodine in normal adults is formulated in this study and it may provide scientific evidence for individual iodine nutritional assessment. Key words: Adults; Serum; Iodine; Reference values

Objective To understand the situation of iodine of Taishan nuclear power station employees, and assess the relationships between iodine nutrition and thyroid nodule of Taishan nuclear power station in Taishan, Guangdong. Methods Totally 300 people were selected from of Taishan nuclear power station through stratified-random sampling method, random urine samples were collected and urinary iodine level was tested in 2014. According to 20 to 29 years old, 30 to 39 years old, 40 to 59 years old, 3 age groups were sampled, and each age group was 100 people. Drinking water and edible salt samples of the of nuclear power station were collected and iodine level was tested. Daily dietary intake of the staff was investigated, and daily iodine intake was calculated. Result of thyroid B ultrasonic of the employees (1 091) were studied, and detection rate of thyroid nodule was calculated. Results Totally 308 urine samples were tested, and the median urinary iodine was 193 μg/L. The difference of urinary iodine between 20-year-old group (201 μg/L) and 30-year-old group (165 μg/L) was statistically significant (P < 0.05). A total of 9 iodized salt samples were collected, with an average iodine value of (24.4 ± 0.5) mg/kg. A total of 9 water samples were collected, the median of water iodine was 20.5 μg/L in 3 centralized water supply samples. The daily iodine intake per capita of the staff was 274.0 μg/d, the highest contribution among all the varieties of food was iodized salt, the second was seafood, which were 45.26 percent and 41.86 percent, respectively. A total of 99 thyroid nodules and suspicious nodules were detected in 1 091, and the prevalence was 9.07 percent (99/1 091). The prevalence of people aged 40-59 [15.6% (22/141)] was significantly higher than those of people aged 20 to 29 [8.1% (51/633)] and aged 30 to 39 [8.2% (26/317)], and the differences were statistically significant (P < 0.05). Conclusions The iodine nutrition of Taishan nuclear power station employees is appropriate as a whole. The detection rate of thyroid nodules is higher in people aged 40 to 59. Key words: Iodine; Thyroid; B ultrasonic; Thyroid nodule

To explore the influences of pregnancy and iodine intake on thyroid function and immune functions, 210 pregnant women and 290 fertile women were chosen from iodine excess area, and the average ages of them were (27. 69±4. 73 )and (30. 62±6. 01 )years respectively. Fasting blood and urine were collected in the morning. The urinary iodine level was determined by arsenic-cerium catalytic contact. Serum free triiodothyronine ( FT3 ), free thyroxine ( FT4 ), and sensitive thyroid-stimulating hormone ( sTSH ) levels were measured by chemiluminescence.Thyroid peroxidase antibody (TPOAb)and thyroglobulin antibody (TGAb)were measured by radioimmunoassay. The median urinary iodine in the pregnant and fertile women were I 240. 70 and 949. 21 μg/L, respectively. There were 84. 3% pregnant women and 81.0% fertile women admitting excess iodine intake. The prevalence of overall thyroid diseases was 22. 9% in the pregnant women and 30. 3% in the fertile women. The prevalence of hyperthyroidism,subclinical hyperthyroidism, hypothyroidism, and subclinical hypothyroidism was0. 5%, 1.9%, 0. 5%, and 20. 0% in the former group, and 2. 8%, 0. 3%, 0. 3%, and 26. 9% in the latter. Both FT3 and FT4 levels of the pregnant women were lower than those of fertile women [(4. 03±0. 59 vs 4. 71 ± 1.04)pmol/L, ( 13. 35 ± 1.59 vs 14. 27 ±3.63 )pmol/L,both P＜0. 01], and the positive rate of TGAb of pregnant women was also lower than that of fertile women (7. 1% vs14. 1%, P=0. 014). The prevalence of thyroid diseases and positive rate of thyroid autoantibodies is high in women with excess iodine intake. Compared with fertile women, pregnancy may lead to decreas~s in level of thyroid hormones and positive rate of TGAb. Their iodine intake should be controlled, and the thyroid function and autoimmunity antibodies should be monitored. Key words: Pregnant women; Fertile women; Excess iodine; Thyroid function; Thyroid autoimmunity function

Objective To explore the impact of iodine nutrition on pregnant women before and after adjusting the iodine content in iodine salt. Methods Twelve counties (areas, cities) in Hangzhou were divided into urban, suburban and rural areas before and after adjusting the iodine content of salt. One survey spot was selected in each district and one hundred pregnant women were selected; family salt and urinary samples of each pregnant woman were collected. The levels of salt and urinary iodine were measured by the methods of picric sodium thiosulfate titrimetric (GB 13025.7-2012) and spectrophotometer (WS/T 107-2006), respectively. Results One thousand two hundred and thirty-nine and one thousand two hundred and thirty-three household salt samples were collected before and after adjusting the iodine content in iodine salt. The median of salt iodine of pregnant women (23.30 mg/kg) before adjusting the iodine content in iodine salt was lower than that after adjusting the iodine content in iodine salt (30.09 mg/kg, χ2=-4.71, P < 0.01). The iodine salt coverage rate and the consumption rate of qualified iodized salt after adjusting the iodine content in iodine salt [93.92% (1 158/1 233), 93.84% (1 157/1 233)]were higher than those before adjusting the iodine content in iodine salt [91.85% (1 138/1 239), 91.37% (1 132/1 239), χ2= 4.01, 5.51, all P < 0.05]. The iodine salt coverage rate and the consumption rate of qualified iodized salt in urban and suburb areas after adjusting the iodine content in iodine salt [99.42% (510/513), 100.00% (203/203), 97.86% (502/513), 100.00% (203/203)] were higher than those before adjusting the iodine content in iodine salt [86.71% (450/519), 98.00% (196/200), 77.26% (401/519), 85.00% (170/200)], but the iodine salt coverage rate and the consumption rate of qualified iodized salt in rural area before adjusting the iodine content in iodine salt [94.62% (492/520), 86.92% (452/520)] were higher than those after adjusting the iodine content in iodine salt [85.69% (443/517), 76.98% (398/517), χ2= 64.22, 2.32, 100.02, 32.90, 23.31, 17.33, all P < 0.05]. One thousand two hundred and thirty-four and one thousand two hundred and thirty-one household urine samples were collected before and after adjusting the iodine content in iodine salt. The median of urinary iodine (MUI, 114.80 μg/L) of pregnant women after adjusting the iodine content in iodine salt was lower than that before adjusting the iodine content in iodine salt (168.60 μg/L, χ2= 36.92, P < 0.01). The MUIs of pregnant women in urban, suburban, and rural areas (171.30, 170.20 and 162.40 μg/L) before adjusting the iodine content in iodine salt were higher than those after adjusting the iodine content in iodine salt (101.00, 149.48 and 119.90 μg/L, χ2=-7.78, -2.63, -6.28, all P < 0.01). The differences of urinary iodine between groups were statistically significant in urban, suburban and rural areas after adjusting the iodine content in iodine salt (χ2= 32.86, P < 0.01), the MUI of pregnant women in urban areas was lower than those in the suburban and rural areas (χ2= 6.70, 8.13, all P < 0.05). Conclusions After adjusting the iodine content of salt in Hangzhou, the iodine-nutrition level of pregnant women is decreased. But the consumption rates of qualified iodized salt and the MUIs in urban, suburb, rural areas are different, so the coverage of iodized salt at household level needs to be enhanced and the health education should be highlighted. Key words: Iodine; Nutrition assessment; Pregnancy; Salt iodization

There is an importent relationship between iodine intake and most thyroid diseases. Both excess and deficiency of iodine intake are risk factors for thyroid diseases. Deficiency of iodine intake is related with the morbidity rate of nodular goiter and thyroid cancer. Excess of iodine intake is related with lots of thyroid diseases including nodular goiter, hyperthyroidism, hypothyroidism, autoimmunity thyroid disease and thyroid neoplasm, which is reported by kinds of literatures. Actually, the morbidity rate of some thyroid disorders was found increasing more or less after the execution of iodine supplements strategy in some areas. Now,the research focuses of thyroid disorders are located in epidemiology, clinical experiments, molecular biology mainly. There has been a discussion about the relationship between iodine intake, thyroid disorders, and the molecular mechanism. Key words: Thyroid disease; Iodine; Iodine intake

Objective To understand the dynamic conditions after reaching the stage goal of elimination of iodine deficiency disorders (IDD) in Wenzhou, and to provide a scientific basis for prevention and treatment of IDD. Methods Three counties that the annual consumption rate of qualified iodized salt < 80% in 2014 and had the prevalence of endemic cretinism in history, Cangnan, Taishun and Yongjia, were selected as high risk monitoring areas. Three townships were selected in each area, and two primary schools were selected from each township, and 40 children urine samples were collected in each school (half male and half female) and the age of children were 8 -10 years old. And near the location of these primary schools, we randomly selected 10 pregnant women in each village, and estimated the urinary iodine level and salt iodine concentration, respectively. The examination of thyroid by B ultrasound was performed in children by provincial professionals. Urinary iodine was determined using the arsenic cerium catalytic spectrophotometric method (GB/T 13025.7-2012). Salt iodine was determined by direct titration. Results Endemic cretinism case was not found in this survey, total goiter rate of 8 -10 years old children was 2.04% (16/783). The median of urinary iodine was 116.1 and 108.2 μg/L, respectively, in 8 -10 years old children and pregnant women. Iodized salt coverage rate was 90.48% (171/189), the intaking rate of qualified iodized salt was 84.66%(160/189). The concentration of pregnant women urinary iodine and salt iodine was positively correlated(r = 0.54,P < 0.05). Conclusions Children's iodine nutrition is in the appropriate level, but pregnant women are in iodine definciency in Wenzhou City. Key words: Iodine deficiency disorders; Goiter rate; Iodine; Salts; Urine iodine