Pregnant women at risk for iodine deficiency but adequate iodine intake in school-aged children of Zhejiang Province, China.

The median urinary iodine concentration (UIC) of school-aged children has been commonly used as a surrogate to assess iodine status of a population including pregnant women. However, pregnant women have higher iodine requirements than children due to increased production of thyroid hormones. The aim of the study was to evaluate the iodine status of pregnant women and children as well as their household salt iodine concentration (SIC) in Quzhou, Zhejiang Province, China. Eligible pregnant women and children from all six counties of Quzhou in 2021 were recruited into the study. They were asked to complete a socio-demographic questionnaire and provide both a spot urine and a household table salt sample for the determination of UIC and SIC. A total of 629 pregnant women (mean age and gestation weeks of 29.6 years and 21.6 weeks, respectively) and 1273 school-aged children (mean age of 9 years and 49.8% of them were females) were included in the study. The overall median UIC of pregnant women and children in our sample was 127 (82, 193) µg/L and 222 (147, 327) µg/L, respectively, indicating sufficient iodine status in children but a risk of mild-to-moderate iodine deficiency in pregnant women. Distribution of iodine nutrition in children varied significantly according to their sex and age (P < 0.05). The rate of adequately household iodised salt samples (18-33 mg/kg) provided by pregnant women and children was 92.4% and 90.6%, respectively. In conclusion, our results indicated a risk of insufficient iodine status in pregnant population of China, but iodine sufficiency in school-aged children. Our data also suggested that median UIC of children may not be used as a surrogate to assess iodine status in pregnant women.

Iodine Excess May Lead to Low Exam Score in Children Aged 8-10 Years.

Recent research has shown that iodine excess may damage children's intelligence. Years of monitoring results in Shanghai show the iodine status has approached the upper limit of the appropriate range for children aged 8-10 years, indicating a risk of iodine excess. We used multi-stage random sampling to select children. Sixteen districts of Shanghai were divided into five units based on geographic location, and one primary school was randomly selected from each unit. In each selected school, about 40 children aged 8-10 years were randomly recruited to measure their urinary iodine concentration (UIC), household salt iodine concentration (SIC), the score of the final unified exam of the last semester, and school canteen salt iodine concentration. The median UIC of 3213 children aged 8-10 years in Shanghai was 195.4 (122.0, 285.8) µg/L and exceeded 200 µg/L in 48.8% of the population. Household and school canteen iodized salt coverage rates were 60.3% and 82.5% respectively, and mean household and school canteen SICs were 21.51 ± 9.30 mg/kg and 25.29 ± 3.40 mg/kg respectively. By correcting for potential confounding factors, logistic regression demonstrated that compared to the adequate iodine status group, students in the slight iodine excess group were less likely to get "A" (score > 90) in math, Chinese, and English exams (Math: OR = 0.775, 95% CI = 0.660-0.911, P = 0.002; Chinese: OR = 0.707, 95% CI = 0.543-0.842, P < 0.001; English: OR = 0.720, 95% CI = 0.610-0.849, P < 0.001). In Shanghai, the iodine status of 8-10-year-old children is approaching the upper limit of the adequate range. Iodine excess in Shanghai may lead to low exam scores for students.

Iodine nutrition status of pregnant women in Qingdao City from 2018 to 2020 / 中华地方病学杂志

Objective:To investigate the iodine nutritional status of pregnant women in Qingdao and the effect of prevention and treatment of iodine deficiency disorders (IDD), so as to provide a basis for residents to supplement iodine scientifically, and take targeted prevention measures and adjust intervention strategies.Methods:In accordance with the requirements of the "National Iodine Deficiency Disorders Surveillance Program (2016 edition)" and "Shandong Iodine Deficiency Disorders Surveillance Program", the cluster sampling method was adopted to select pregnant women from 10 districts (cities) in Qingdao from 2018 to 2020, to investigate their basic information and thyroid disease history. Meanwhile, household edible salt samples and random urine samples were collected to detect iodine content.Results:A total of 3 000 pregnant women were monitored from 2018 to 2020, the median age was 31 years, and the median gestational age was 18 weeks. There were significant differences in the distribution of age, gestational age, whether senile puerpera, and pregnancy in different years ( H/χ 2 = 29.35, 81.03, 65.62, 77.34, P < 0.001). The median salt iodine of edible salt ( n = 3 000) and iodized salt ( n = 2 700) in pregnant women's homes were 23.02 and 23.70 mg/kg, respectively. The qualified rate of iodized salt, the coverage rate of iodized salt and the consumption rate of qualified iodized salt were 89.59% (2 419/2 700), 90.00% (2 700/3 000) and 80.63% (2 419/3 000). The comparison of qualified rate of iodized salt, coverage rate of iodized salt and consumption rate of qualified iodized salt among different years was statistically significant (χ 2 = 48.09, 36.62, 61.08, P < 0.001), the coverage rate of iodized salt and the consumption rate of qualified iodized salt showed a downward trend year by year (χ 2trent = 35.54, 29.50, P < 0.001). A total of 3 000 urine samples were collected from pregnant women and the median urinary iodine of pregnant women was 147.85 μg/L. The urinary iodine level in the third trimester was lower than that in the first and second trimesters ( P < 0.001). The urinary iodine level in the non elderly group was higher than that in the elderly group ( Z = - 6.66, P < 0.001). The urinary iodine level in the group without thyroid disease was higher than that in the group with thyroid disease ( Z = - 1.99, P = 0.047). The urinary iodine level in iodized salt group was higher than that in non-iodized salt group ( Z = - 2.42, P = 0.015). Conclusions:The iodine nutrition of pregnant women in Qingdao is generally at an insufficient level, and the risk of iodine deficiency is high, which needs attention. In recent years, the coverage rate of iodized salt and the consumption rate of qualified iodized salt in Qingdao have shown a downward trend, and have failed to meet the requirements of national standards. In the future, we should strengthen the monitoring and health education of IDD in pregnant women.

Analysis of iodine nutrition status of children aged 8 - 10 and pregnant women in Fushun City, Liaoning Province in 2021 / 中华地方病学杂志

Objective:To study the iodine nutrition status of children aged 8 to 10 and pregnant women and thyroid of children in Fushun City, Liaoning Province, and to provide data for formulation of prevention and control programs on iodine deficiency disorders in Fushun.Methods:In 2021, according to population probability proportional sampling method (PPS), 1 street (township) was selected from 7 districts and counties (Dongzhou District, Wanghua District, Dongzhou District, Xinfu District, Fushun County, Xinbin County and Qingyuan County) in Fushun City according to 5 directions (east, south, west, north and middle) and 1 primary school was selected from each street (township). Forty to 50 children aged 8 to 10 from each primary school and 20 pregnant women were selected from each street (township). Urine samples and salt samples of children and pregnant women were collected for urine iodine and salt iodine levels detection, and thyroid gland of children was examined to calculate the goiter rate. Urine iodine was determined by "Determination of Iodine in Urine Part 1: Method for Determination of Iodine in Urine by As 3+-Ce 4+ Eatalytic Spectrophotometry", salt iodine was determined by "General Test Method in Salt Industry - Determination of Iodine", and children's thyroid was examined by Doppler B-ultrasound. Children iodine nutrition criteria: urinary iodine median < 100 μg/L was iodine deficiency; 100 - < 200 μg/L was suitable for iodine; 200 - < 300 μg/L was more than the appropriate amount of iodine; ≥300 μg/L was iodine excess. Pregnant women iodine nutrition criteria: urinary iodine median < 150 μg/L was iodine deficiency; 150 - < 250 μg/L was suitable for iodine. 250 - < 500 μg/L was more than the appropriate amount of iodine; ≥500 μg/L was iodine excess. Criteria for iodized salt: 18 - 33 mg/kg was qualified iodized salt; < 5 mg/kg was non-iodized salt; 5 - < 18 or > 33 mg/kg was unqualified iodized salt. Results:A total of 1 647 children aged 8 to 10 years were selected, including 829 males and 818 females. The median urinary iodine of children was 203.4 μg/L. The median urinary iodine of children by district and county ranged from 151.6 to 232.4 μg/L, and the difference was statistically significant ( H = 24.227, P < 0.001). A total of 700 urine samples were collected from pregnant women. The median urine iodine was 164.7 μg/L. The median urine iodine of pregnant women by district and county ranged from 131.3 to 193.0 μg/L, and the difference was statistically significant ( H = 48.516, P < 0.001). A total of 2 347 salt samples were collected, including 2 329 iodized salt samples, with iodized salt coverage rate of 99.23% (2 329/2 347). There were 2 254 qualified iodized salt samples, and the rate of qualified iodized salt was 96.04% (2 254/2 347). There was no correlation between total urinary iodine level and salt iodine content ( r = 0.129, P > 0.05). The thyroid gland of 1 439 children was examined, and 25 children of them had goiter, with an enlargement rate of 1.74% (25/1 439), lower than the national standard for elimination of iodine deficiency disorders (< 5%), and the difference between counties and districts was statistically significant (χ 2 = 31.692, P < 0.01). Conclusion:The iodine nutrition of 8 to 10 years old children and pregnant women in Fushun City, Liaoning Province in 2021 is basically at an appropriate level, the rate of qualified iodized salt is high, and the goiter rate of children conforms to the national elimination standards of iodine deficiency disorders.

External quality control assessment results of iodine deficiency disorders laboratory in Qinghai Province in 2021 / 中华地方病学杂志

Objective:To analyze the external quality control assessment results of urinary iodine, salt iodine and water iodine in iodine deficiency disorders laboratories in Qinghai Province, to evaluate the testing capacity of provincial, municipal and county-level laboratories and the operation of external quality control network, so as to provide quality assurance for consolidating and eliminating iodine deficiency disorders.Methods:In 2021, 1 provincial, 8 municipal, and 43 county-level laboratories in Qinghai Province had participated in the assessment of urinary iodine and salt iodine, while 1 provincial and 8 municipal-level laboratories had participated in the assessment of water iodine. The assessment results were evaluated using the method of reference value ± uncertainty of external quality control samples.Results:All laboratories that participated in the assessment had provided feedback. One provincial-level laboratory passed the assessment of urinary iodine, salt iodine, and water iodine. Among 8 municipal-level laboratories, 2 laboratories failed the urinary iodine assessment, with a pass rate of 6/8; the assessment of salt iodine and water iodine in 8 laboratories were all qualified. Among 43 county-level laboratories, 7 laboratories failed the urinary iodine assessment, with a pass rate of 83.7% (36/43); the assessment of salt iodine in 43 laboratories were all qualified.Conclusions:The external quality control network of iodine deficiency disorders laboratories in Qinghai Province has fully covered all municipal and county-level laboratories. The testing capability of provincial-level laboratory is stable and maintains a high level; the testing quality of some municipal and county-level laboratories is still unstable and needs to be further strengthened.

Monitoring results of iodine deficiency disorders among children aged 8 - 10 in non-high water iodine areas of Inner Mongolia Autonomous Region in 2021 / 中华地方病学杂志

Objective:To study the iodine nutrition status of children in non-high water iodine areas of Inner Mongolia Autonomous Region, analyze the monitoring results of iodine deficiency disorders, so as to provide a basis for further guidance on scientific iodine supplementation for children in Inner Mongolia Autonomous Region.Methods:According to the requirements of the National IDD Monitoring Program and the IDD Monitoring Program of Inner Mongolia in 2021, cluster sampling method was used to select non boarding children aged 8 - 10 from 104 counties (cities, districts) in 12 cities within the jurisdiction of Inner Mongolia Autonomous Region. Random urine samples and household salt samples were collected to detect iodine content. At the same time, 1/3 of the selected children were selected for thyroid B-ultrasound examination to measure thyroid volume.Results:In 2021, a total of 19 968 children aged 8 - 10 in non-high water iodine areas of Inner Mongolia were monitored, and 19 968 urine samples were collected, with a median urine iodine of 199.23 μg/L. There was a statistically significant difference in the frequency distribution of urinary iodine in different cities (χ 2 = 839.51, P < 0.001). The median iodine content of children's household edible salt was 22.64 mg/kg, and the coverage rate of iodized salt, qualified iodized salt coverage rate, and non-iodized salt rate in the entire region was 99.05% (19 778/19 968), 94.98% (18 785/19 778), 94.08% (18 785/19 968) and 0.95% (190/19 968), respectively. Thyroid B-ultrasound were performed in 6553 children, the goiter rate was 1.30% (85/6 553), and there were statistically significant differences in goiter rates among children of different ages and cities (χ 2 = 87.09, P < 0.001; χ 2 = 10.40, P = 0.006) . Conclusions:In 2021, the iodine nutrition of children aged 8 - 10 in non-high water iodine areas of Inner Mongolia is at an appropriate level. However, in the future we should continue to adhere to the monitoring of iodine deficiency disorders, strengthen health education on iodine deficiency disorders, consolidate existing achievements in iodine deficiency disease prevention and control, and achieve the goal of continuous elimination of iodine deficiency disorders.

Surveillance results of iodine deficiency disorders in key populations in Ganzhou City, Jiangxi Province from 2018 to 2022 / 中华地方病学杂志

Objective:To investigate the status of iodine deficiency disorders in children and pregnant women in Ganzhou City, Jiangxi Province, and to provide a basis for scientific iodine supplementation and adjustment of prevention and control strategies.Methods:According to the requirements of the National Iodine Deficiency Disorders Surveillance Program (2016 Edition), iodine deficiency disorders surveillance was carried out in 18 counties (cities, districts) under the jurisdiction of Ganzhou City from 2018 to 2022. Edible salt and urine samples taken from children aged 8 to 10 and pregnant women were collected to detect salt and urine iodine levels. At the same time, B-ultrasound method was adopted to measure children's thyroid volume, and the goiter rate was calculated.Results:From 2018 to 2022, a total of 27 075 edible salt samples were collected from key populations (children aged 8 - 10 and pregnant women), with a median salt iodine of 25.00 mg/kg and a qualified iodized salt consumption rate of 96.24% (26 057/27 075). The difference in the qualified iodized salt consumption rate among key populations in different years was statistically significant (χ 2 = 29.09, P < 0.001). A total of 18 061 urine samples were collected from children, with a median urine iodine of 192.10 μg/L, there was a statistically significant difference in the urine iodine level of children between different years ( H = 82.59, P < 0.001). A total of 9 014 urine samples were collected from pregnant women, with a median urine iodine of 177.20 μg/L, there was a statistically significant difference in urine iodine level of pregnant women between different years ( H = 78.78, P < 0.001). A total of 8 621 children's thyroid glands were examined, including 34 cases of goiter, with a goiter rate of 0.39%, and the goiter rate showed a decreasing trend year by year (χ 2trend = 11.09, P < 0.001). Conclusions:From 2018 to 2022, the iodine nutrition of children and pregnant women in Ganzhou City is at an appropriate level, the consumption rate of qualified iodized salt (> 90%) and the children's goiter rate (< 5%) met the national iodine deficiency disorders elimination standards. Ganzhou City continues to maintain the status of eliminating iodine deficiency disorders.

Analysis of monitoring results of iodine deficiency disorders in Nanning City in 2020 / 中华地方病学杂志

Objective:To analyze the monitoring results of iodine deficiency disorders in Nanning City in 2020, learn about the consumption of iodized salt among residents and the iodine nutrition status of key populations, and provide scientific basis for formulating or adjusting targeted prevention and control measures of iodine deficiency disorders.Methods:According to the Guangxi Iodine Deficiency Disorders Monitoring Plan, monitoring was carried out in all of 12 districts (counties) in Nanning City. One township (street) was selected from each of the five directions of east, west, south, north, and central. Forty non-boarding children aged 8 to 10 and 20 pregnant women were selected as monitoring subjects in each township (street). Edible salt samples were collected from children and pregnant women to detect salt iodine content, random mid-course urine samples from children and morning urine samples from pregnant women were collected to detect urinary iodine content; in addition, thyroid examination of children was conducted in Qingxiu District, Liangqing District, Long an County and Shanglin County.Results:In 2020, a total of 2 434 children aged 8 to 10 and 1 207 pregnant women were surveyed in Nanning City. The coverage rate of iodized salt, the qualified rate of iodized salt and the qualified iodine salt consumption rate were 99.67%(3 629/3 641), 97.99%(3 556/3 629) and 97.67%(3 556/3 641), respectively. The median urinary iodine of children was 182.0 μg/L, and the median values ranged from 146.5 to 234.8 μg/L in different districts (counties), there were significant differences in median urinary iodine between urban and non-urban areas, different gender and age groups ( U = 2.38, 2.41, P = 0.017, 0.016; H = 16.42, P < 0.001). The goiter rate of children was 0.99%(8/807), and the rate ranged from 0 to 2.00% (4/200) in the 4 districts (counties) examined, there were significant differences in thyroid volume between urban and non-urban areas and different ages ( U = - 3.52, P < 0.001; H = 47.67, P < 0.001). The median urinary iodine of pregnant women was 191.0 μg/L. The median urinary iodine of different districts (counties) ranged from 141.0 to 241.5 μg/L, and the difference was statistically significant at different gestational stages ( H = 24.37, P < 0.001). Conclusion:In 2020, the coverage rate of iodized salt, the qualified rate of iodized salt and the qualified iodine salt consumption rate by residents in Nanning City are high, and the iodine nutrition of both children and pregnant women are at an appropriate level.

Iodine check results in edible salt in Suzhou in 2017-2021 / 公共卫生与预防医学

Objective To understand the quality status of salt iodine monitoring results at the county level and checking results at the city level from 2017 to 2021 in Suzhou，and to provide a scientific basis for the development of iodine deficiency disease（IDD）prevention and control strategies and measures.  Methods During the past five years, Suzhou CDC randomly selected 15 samples of 300 monitored salt samples from each county/district CDC each year for spot checks. The data were processed by comparative analysis of relative error and grouped data t test.  Results In the conformity of iodized salt and non-iodized salt, the sample monitoring results of some counties/districts were non-iodized salt, while the city-level test results were iodized salt. In the conformity of iodized salt and seaweed iodized salt (or enhanced salt), the sample monitoring results of county/district level were iodized salt, while the test results at the city level were seaweed iodized salt (or enhanced salt). The non-conformity was relatively concentrated in some county/district laboratories, and the total amount of non-conformity tended to increase year by year. The total number of samples with relative error of >20% between the county/district and city-level results was the least in 2021, with 6, and the most in 2018, with 25. The number of samples with relative error of >30% between the county/district and city-level results was the least in 2017 being 0, while there were 12 samples in 2018, fluctuating within a small range in the past three years. The t-test results of grouped data showed that the average value of the checking results at the city level was generally higher than the monitoring results at the county level. There were 21 pairs of data with no statistical significance (P>0.05) and 29 pairs of data with statistical significance (P<0.05) between the results at the county/district level and at the city level. Among them, there were 7 counties/districts whose sample monitoring results were not significantly different from the city-level test results in 2020, while there were 9 counties/districts whose monitoring results were statistically different from the city-level test results in 2021.  Conclusion  The data analysis results show that the monitoring data of iodized salt in Suzhou is basically reliable and accurate, but there still exist some problems. Therefore, in the future work it is necessary to strengthen the monitoring system of IDD, increase training efforts, continuously monitor and check the quality of iodized salt to provide a scientific basis for effective prevention and control of IDD.

Time Series and Spatial Epidemiological Analysis of the Prevalence of Iodine Deficiency Disorders in China.

Objective: To recognize the spatial and temporal characteristics of iodine deficiency disorders (IDD), China national IDD surveillance data for the years of 1995-2018 were analyzed. Methods: Time series analysis was used to describe and predict the IDD related indicators, and spatial analysis was used to analyze the spatial distribution of salt iodine levels. Results: In China, the median urinary iodine concentration increased in 1995-1997, then decreased to adequate levels, and are expected to remain appropriate in 2019-2022. The goiter rate continually decreased and is expected to be maintained at a low level. Since 2002, the coverage rates of iodized salt and the consumption rates of qualified iodized salt (the percentage of qualified iodized salt in all tested salt) increased and began to decline in 2012; they are expected to continue to decrease. Spatial epidemiological analysis indicated a positive spatial correlation in 2016-2018 and revealed feature regarding the spatial distribution of salt related indicators in coastal areas and areas near iodine-excess areas. Conclusions: Iodine nutrition in China showed gradual improvements. However, a recent decline has been observed in some areas following changes in the iodized salt supply in China. In the future, more regulations regarding salt management should be issued to strengthen IDD control and prevention measures, and avoid the recurrence of IDD.

Analysis of surveillance results of iodine deficiency disorders in Jingdezhen City of Jiangxi Province from 2017 to 2020 / 中华地方病学杂志

Objective:To analyze the iodine content distribution of drinking water in Jingdezhen City, and master the status of prevention and control of iodine deficiency disorders (IDD), so as to provide a basis for adopting targeted control measures and scientific adjustment of control and prevention strategies.Methods:According to the "National Iodine Deficiency Disorders Surveillance Program" and the "National Water Iodine Content Survey Program for Drinking Water", the surveillance of IDD in Jingdezhen City was carried out from 2017 to 2020. Household edible salt samples from pregnant women and students aged 8 to 10 were collected to detect salt iodine content, and urine samples were collected to detect urinary iodine. Thyroid volume of students was measured by B-ultrasonography, and the rate of goiter was calculated. In 2017, the iodine content of drinking water in Jingdezhen City was investigated, and the results were analyzed.Results:From 2017 to 2020, a total of 1 800 students were examined for thyroid gland, and 11 students were found to have goiter, with an goiter rate of 0.61%. A total of 3 201 edible salt samples and 3 201 urine samples were collected from students, the median of salt iodine was 24.96-26.40 mg/kg, the consumption rate of qualified iodized salt was 98.50%-99.50%, and the median of urinary iodine was 172.56-218.35 μg/L. A total of 1 600 edible salt samples and 1 600 urine samples were collected from pregnant women, the median of salt iodine was 24.40-25.38 mg/kg, the consumption rate of qualified iodized salt was 97.25%-98.00%, and the median of urinary iodine was 161.55-205.60 μg/L. In 2017, a total of 667 water samples were collected from 52 villages and towns in 4 counties and districts. The median of water iodine of the 4 counties and districts was 0.6-3.2 μg/L, and that of the 52 villages and towns was 0.3-12.3 μg/L.Conclusions:The iodine nutrition level of students and pregnant women in Jingdezhen City is generally at an appropriate level, but the iodine content of drinking water is low. It is suggested to strengthen the health education and health promotion of IDD among key population, guide the residents to supplement iodine scientifically, and continuously eliminate the harm of IDD.

Surveillance results of iodine deficiency disorders in children aged 8-10 years in Qingdao City from 2018 to 2020 / 中华地方病学杂志

Objective:To investigate the iodine nutritional status of children in Qingdao City and the effects of prevention and treatment measures on iodine deficiency disorders (IDD), and to provide a scientific basis for guiding residents to scientifically supplement iodine, taking timely targeted prevention and control measures, and scientifically adjusting intervention strategies.Methods:According to "National Iodine Deficiency Disorders Surveillance Program (2016 edition)" and "Iodine Deficiency Disorders Surveillance Program of Shandong Province", from 2018 to 2020, using the cluster sampling method, children aged 8-10 years in Qingdao City were chosen to test their household salt iodine content and random urinary iodine content, and to examine their thyroid volume by B-ultrasonography, and the correlation between thyroid volume and physical development indexes was analyzed.Results:From 2018 to 2020, a total of 6 057 children were monitored, including 3 068 boys and 2 989 girls. The median of salt iodine and iodized salt iodine of children was 23.50 and 24.10 mg/kg. The qualified rate of iodized salt was 89.95% (4 832/5 372), the coverage rate of iodized salt was 88.69% (5 372/6 057), and the consumption rate of qualified iodized salt was 79.78% (4 832/6 057). There were significant differences in the qualified rate of iodized salt, the coverage rate of iodized salt and the consumption rate of qualified iodized salt between different years (χ 2 = 135.26, 314.71, 342.87, P < 0.001). A total of 6 057 urine samples were collected from children, and the median of urinary iodine was 193.92 μg/L, of which 16.2% (979/6 057) were < 100 μg/L, and 22.5% (1 361/6 057) were ≥300 μg/L. There were statistically significant differences in the medians of urinary iodine between different years, gender and whether eating iodized salt ( H/Z = 37.25,-3.89,-5.69, P < 0.001), the median of urinary iodine in boys was higher than that of girls, and the median of urinary iodine in eating iodized salt group was higher than that of eating non-iodized salt group. There was no significant difference in the median of urinary iodine between different age ( H = 4.33, P = 0.119). The rate of goiter in children was 3.45% (71/2 057), and the difference between different years was statistically significant (χ 2 = 42.68, P < 0.001). The incidence of goiter in 2020 [7.31% (45/616)] was significantly higher than that in 2018 and 2019 [2.81% (18/641), 1.00% (8/800), P < 0.001]. Thyroid volume of children was positively correlated with height and weight ( r = 0.20, 0.22, P < 0.001). Conclusions:The iodine nutritional level of children aged 8-10 years in Qingdao City is appropriate. However, the incidence of goiter in children in some years is relatively high. The qualified rate of iodized salt, the coverage rate of iodized salt and the consumption rate of qualified iodized salt are all lower than the national standard for elimination of IDD, which should be paid attention to.

Iodine intake among pregnant mothers residing in hilly terrains of two districts of Himachal Pradesh, India.

BACKGROUND: Under programmatic settings, routine monitoring and evaluation of household consumption of iodized salt are recommended to track the reach of universal salt iodization strategy. The program needs evaluation in different settings and locations. OBJECTIVE: The objective of this study was to assess urine-based estimation for recent iodine intake among pregnant women living in hilly terrains of two districts of northern state of India. METHODS: A community-based cross-sectional observational study was conducted during September- December 2019 among 202 randomly selected pregnant women in two districts of Himachal Pradesh. With a predesigned schedule, data regarding sociodemographic and behavioral factors and salt consumption were collected by interview. Iodine level of salt was assessed by spot iodine testing kit and urinary iodine concentration (UIC) was measured using ammonium persulfate digestion using spectrophotometer. RESULTS: Women had a mean age of about 26 years, and the period of gestation was of mean 163.7 days. The consumption of iodized salt (>15 ppm) at family level was found to be 83.7%, and the median UIC was 169.0 µg/L. Among assessed, 26.7% had an acceptable level of UIC, whereas 41.1% and 32.2% of women had less (<150 µg/L) and excessive (>250 µg/L) level of UIC, respectively. CONCLUSION: Recent iodine intake among pregnant women was observed to be adequate, but efforts are to be done to assess the reasons for less and excessive UIC among women.

Assessment of iodine nutrition of schoolchildren in Gonda, India, indicates improvement and effectivity of salt iodisation.

OBJECTIVE: To study the total goitre rate (TGR), urinary iodine concentration (UIC) and salt iodine content among schoolchildren in a previously endemic area for severe iodine deficiency disorder (IDD). DESIGN: Cross-sectional epidemiological study. SETTING: The study was carried out in the Gonda district (sub-Himalayan region) of North India. PARTICIPANTS: Nine hundred and seventy-seven schoolchildren (6-12 years) were studied for parameters such as height, weight, UIC and salt iodine content. Thyroid volume (TV) was measured by ultrasonography to estimate TGR. RESULTS: The overall TGR in the study population was 2·8 % (95 % CI 1·8, 3·8). No significant difference in TGR was observed between boys and girls (3·5 % v. 1·9 %, P = 0·2). There was a non-significant trend of increasing TGR with age (P = 0·05). Median UIC was 157·1 µg/l (interquartile range: 94·5-244·9). At the time of the study, 97 % of salt sample were iodised and nearly 86 % of salt samples had iodine content higher than or equal to 15 part per million. Overall, TGR was significantly lower (2·8 % v. 31·0 %, P < 0·001), and median UIC was significantly higher (157·1 v. 100·0 µg/l, P < 0·05) than that reported in the same area in 2009. CONCLUSIONS: A marked improvement was seen in overall iodine nutrition in the Gonda district after three and a half decades of Universal Salt Iodisation (USI). To sustainably control IDD, USI and other programmes, such as health education, must be continuously implemented along with putting mechanisms to monitor the programme at regular intervals in place.

The Impact of Double-Fortified Salt Delivered Through the Public Distribution System on Iodine Status in Women of Reproductive Age in Rural India.

BACKGROUND: Double-fortified salt (DFS) with iron and iodine has been demonstrated to be efficacious but questions of unintended effects on the gains in salt iodization remain. The main cross-sectional study based on the use of DFS over 1 y showed a reduction in iron deficiency risk. Whether the programs and the levels of added iron can adversely affect iodine status is yet to be established. OBJECTIVES: We hypothesized that the addition of iron to iodized salt can adversely affect iodine status in women of reproductive age (WRA). METHODS: A cross-sectional substudy was conducted in 4 matched-pair adjacent districts of rural Uttar Pradesh, India, in 2019. Under the public distribution system (PDS), DFS was available for 1 y through Fair Price Shops, in the 2 DFS supply districts (DFS-SDs). In these districts, iodized salt was also available in the market. In the 2 compared DFS nonsupply districts (DFS-NSDs), only iodized salt was available. In the substudy, participants included WRA (n = 1624) residing in rural areas of the selected districts. Iodine content in urine and salt samples was measured in each of the groups. RESULTS: Significantly fewer women from the DFS-SDs had median urinary iodine concentration values indicative of moderate to mild iodine deficiency compared with the women from the DFS-NSDs. The salt purchase pattern and iodine content revealed that significantly fewer (21.99%) households in the DFS-SDs were purchasing inadequately iodized crystal salt, compared with 36.04% households in the DFS-NSDs. CONCLUSIONS: The data reject the working hypothesis and suggest a beneficial effect of the DFS program on the iodine status in WRA, thereby supporting a recommendation of DFS supply through the PDS.

Association of iodine-related knowledge, attitudes and behaviours with urinary iodine excretion in pregnant women with mild iodine deficiency.

BACKGROUND: Subsequent to the implementation of the universal salt iodisation policy, China has all but eliminated the iodine deficiency disorders. However, pregnant women are still experiencing mild iodine deficiency. The present study explored factors that could relate to mild iodine deficiency in pregnant women. METHODS: In total, 2400 pregnant women were enrolled using a multistage, stratified, random sampling method in Shanghai. Data were collected via a standardised questionnaire. The urine samples and household cooking salt samples were collected for the detection of urinary iodine and salt iodine concentrations. RESULTS: The median urinary iodine concentration (MUIC) was 148.0 µg L-1 for all participants, and 155.0 µg L-1 , 151.0 µg L-1 and 139.6 µg L-1 in the first, second and third trimesters. The MUIC in the third trimester was significantly lower than that of the first trimester (P < 0.05). The usage rates of iodised salt and qualified-iodised salt were 71.5% and 59.4%, respectively. Iodine-related knowledge score composition ratio was significantly different between the high and low UIC groups (P < 0.05). Participants' MUIC increased significantly with the increases in iodine-related knowledge score (P < 0.001). The third trimester was a significant risk factor for high UIC, whereas high iodine-related knowledge score, actively learning dietary knowledge and having a habit of consuming iodine-rich food were significant protective factors for high UIC (P < 0.05). CONCLUSIONS: Iodine level is adequate among pregnant women in Shanghai during the first and the second trimesters, although it is is insufficient in the third trimester. Good iodine-related knowledge, attitudes and behaviours are important for pregnant women with respect to maintaining adequate urinary iodine.

Iodine nutrition and prevalence of sonographic thyroid findings in adults in the Heilongjiang Province, China.

BACKGROUND: Thyroid disease and thyroid nodules are common clinical problems. Iodine nutrition plays an important role in thyroid disease evolution. Here, we aimed to estimate the iodine nutritional status and prevalence of thyroid disease in the adults of the Heilongjiang Province in northeast China. METHODS: We performed a cross-sectional ultrasound (US)-based survey on volunteers aged 20-70 years from 30 regions of the Heilongjiang Province. The participants were recruited using the probability proportional to size (PPS) method, and consent for US screening was obtained from them. The survey was performed by trained technicians using the same US equipment with a 6-15 MHz linear transducer (MyLab 30 cv, Italy) and was hosted in public community locations such as local hospitals and outpatient departments. Information on basic demographic characteristics, such as urinary iodine and iodine intake were collected. The age- and sex-adjusted prevalence of thyroid disease was determined through direct standardization and reported using the province's population in 2016 as reference. RESULTS: From December 12, 2017, to March 10, 2019, 3,754 participants with a mean age of 48.65 (±12.39) years participated in the study. Of them, 3,643 had reliable urinary iodine data. The median urinary iodine and salt iodine concentrations within the normal range were 163.30 µg/L and 24.30 mg/kg, respectively. The age- and sex-adjusted prevalence of thyroid disease was 52.91%. Diffuse thyroid disease (DTD), focal thyroid lesions (FTL), and coexistence of both diseases were prevalent in 8.68%, 36.58%, and 7.65% of the participants, respectively. The prevalence of the five categories according to US-based survey features in the ACR TI-RADS (i.e., TR1, TR2, TR3, TR4, and TR5) was 7.71%, 14.53%, 3.44%, 14.82%, and 3.51%, and the prevalence of nodules that needed fine-needle aspiration was 2.55%. CONCLUSIONS: In Heilongjiang Province, adults aged 20-70 years belong to the optimal iodine status. Further, the salt iodine levels are in the normal range. Thyroid diseases are highly prevalent in this age group; however, the intervention rate is low. We provided population-based estimates of the prevalence of thyroid disease and the iodine status in adults of Heilongjiang Province. These findings are useful to support effective intervention planning for thyroid disease.

Relationship of household cooking salt and eating out on iodine status of pregnant women in environmental iodine-deficient coastal areas of China.

As city residents eat out more frequently, it is unknown that if iodised salt is still required in home cooking. We analysed the relationship of household salt and eating out on urinary iodine concentration (UIC) in pregnant women. A household condiment weighing method was implemented to collect salt data for a week. A household salt sample was collected. A urine sample was taken at the end of the week. Totally, 4640 participants were investigated. The median UIC was 139·1 µg/l in pregnant women and 148·7, 140·0 and 122·9 µg/l in the first, second and third trimesters. Median UIC in the third trimester was lower than in the other trimesters (P < 0·001). The usage rates of iodised (an iodine content ≥ 5·0 mg/kg) and qualified-iodised (an iodine content ≥ 21·0 mg/kg) salt were 73·9 and 59·3 %. The median UIC in the qualified-iodised salt group was higher than in the non-iodised group (P = 0·037). The median UIC in the non-iodised group who did not eat out was lower than in qualified-salt groups who both did and did not eat out (P = 0·007, <0·001). The proportion of qualified-iodised salt used in home cooking is low, but foods eaten out have universal salt iodisation according to the national compulsory policy. Household iodised salt did not play a decisive role in the iodine status of pregnant women. Pregnant women in their third trimester who are not eating out and using non-iodised salt at home require extra iodine.

Appropriate Range of Median Urinary Iodine Concentration in 8- to 10-Year-Old Children Based on Generalized Additive Model.

Background: The appropriate range of median urinary iodine concentration (MUI) in children has always been controversial. To prevent the occurrence of a goiter epidemic in Shanghai, we explored the appropriate range of MUI by integrating multiple monitoring results. Methods: This study summarized and analyzed the monitoring data from 1997, 1999, 2011, 2014, and 2017 of children living in Shanghai. In each monitoring year, the probability-proportional-to-size sampling technique was used to select 30 sampling units. In each sampling unit, one primary school was randomly selected. From each selected school, 40 children 8- to 10-year-old were randomly recruited to measure thyroid volume (Tvol) and their household salt iodine intake. Results: In 1997, 1999, 2011, 2014, and 2017, MUI of 8- to 10-year-old children was 228, 214, 182, 171, and 183 µg/L, and median Tvol (MTvol) was 2.9, 1.2, 1.0, 1.8, and 2.8 mL, respectively. There was a linear correlation between goiter rate and MTvol (r = 0.95, p = 0.014; 100 × goiter rate = 1.314 × MTvol -1.287). Generalized additive model (GAM) was used to predict MTvol as follows, MTvol = 0.60689 + 0.00302 MUI +0.999928 s (MUI) -0.05172 mean salt iodized concentrations (MSIs) +0.03481 × 100 × iodized salt coverage rate +0.00000969 per capita disposable income +0.271422 s (per capita disposable income) -0.38772 × monitoring year gap. The results revealed that the average relative error between predicted and actual value was 15.2%. GAM results showed that at 27-277 µg/L MUI, the goiter rate was <5%. Conclusions: Iodine status is appropriate in Shanghai. Under the existing economy and MSI, the optimal range of MUI should be 70-277 µg/L in 8- to 10-year-old children living in Shanghai.

Iodine Status of Brazilian School-Age Children: A National Cross-Sectional Survey.

Salt iodization is the main public health policy to prevent and control iodine deficiency disorders. The National Salt Iodization Impact Assessment Survey (PNAISAL) was conducted to measure iodine concentration among Brazilian schoolchildren. A survey including 6-14-year-old schoolchildren from public and private schools from all 26 Brazilian states and the Federal District was carried out in the biennia 2008-2009 and 2013-2014. Municipalities, schools, and students were randomly selected. Students were interviewed at school using a standard questionnaire, which included the collection of demographic, educational, weight, height, and 10 mL non-fasting urine collection information. The analyses were weighted according to the population of students per federative unit. The median urinary iodine concentration (MUIC) for the entire sample by region, federative unit per school, and student characteristics, was described from the cutoff points defined by the World Health Organization (severe disability: <20 µg/L, moderate: 20-49 µg/L, mild: 50-99 µg/L, adequate: 100-199 µg/L, more than adequate: 200-299 µg/L, and excessive: >300 µg/L). In total, 18,864 students (95.9% of the total) from 818 schools in 477 municipalities from all federative units were included in this study. Almost 70% were brown skin color, nine-years-old or older, studied in urban schools, and were enrolled in elementary school. The prevalence of overweight/obesity, as measured by body mass index (BMI) for age, was about twice as high compared to nutritional deficits (17.3% versus 9.6%). The MUIC arrived at 276.7 µg/L (25th percentile = 175.5 µg/L and 75th percentile = 399.71 µg/L). In Brazil as a whole, the prevalence of mild, moderate, and severe deficit was 6.9%, 2.6%, and 0.6%, respectively. About one-fifth of the students (20.7%) had adequate iodine concentration, while 24.9% and 44.2% had more than adequate or excessive concentration, respectively. The prevalence of iodine deficits was significantly higher among younger female students from municipal public schools living in rural areas with the lowest BMI. The median urine iodine concentration showed that Brazilian students have an adequate nutritional intake, with a significant proportion of them evidencing overconsumption of this micronutrient.