Effect of Reduction in Iodine Content of Edible Salt on the Iodine Status of the Chinese Population / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The aim of this study was to evaluate the impact of the revised Chinese National Standard GB26878-2011 'Iodine Content in Edible Salt' on the iodine status among the Chinese population.</p><p><b>METHODS</b>In 2011 and 2014, the probability proportionate to size sampling (PPS) was used in each Chinese province to obtain the representative data. In each sampling unit, school children aged 8-10 years and pregnant women were selected. Key indicators included urinary iodine concentration (UIC), thyroid volume (TV), and the iodine content in edible household salt.</p><p><b>RESULTS</b>The median urinary iodine concentration (MUIC) decreased between 2011 and 2014 from 238.6 to 197.9 µg/L in school-age children. The number of provinces with iodine excess decreased to zero. The proportion of children whose UIC was > 300 µg/L was 18.8% and decreased to 11% compared with 29.8% in 2011. There was no significant difference in UIC < 50 µg/L between 2014 (4.3%) and 2011 (3.7%) (P > 0.05). The MUIC among pregnant women in 2014 was more concentrated between 110 and 230 µg/L. The goiter rate among children aged 8-10 years was unchanged, both the goiter rate of 2011 and 2014 remaining below 5%, in view of the sustainable elimination of iodine deficiency disorders.</p><p><b>CONCLUSION</b>The National Standard GB26878-2011 'Iodine Content in Edible Salt' that was introduced in March 2012 resulted in an overall improvement in iodine status, reducing the risk of excessive iodine intake in the Chinese population.</p>

Deficiencia de yodo en mujeres lactantes / Iodine deficiency in breastfeeding mothers

El yodo es un elemento esencial para la síntesis de hormonas tiroideas (HT), necesarias para el desarrollo del cerebro. Los grupos más vulnerables a la deficiencia de yodo (DY) son las embarazadas, mujeres lactantes y niños menores de dos años. La ingesta de yodo y el estado nutricional del yodo en la madre lactante, está fuertemente relacionada con la secreción del micronutriente en leche materna (LM). Como la mayor parte del yodo absorbido por el organismo es excretada en orina, la mediana de concentración de yodo urinario (CYU), es el mejor indicador bioquímico empleado para evaluar la situación nutricional del yodo en mujeres lactantes y niños menores de dos años. Con base en la CYU en escolares de la mayoría de los países de Latinoamérica, la ingesta de yodo resultó adecuada. Sin embargo, la suficiencia de yodo en escolares no siempre se corresponde con una adecuada ingesta de yodo en mujeres lactantes. Se ha dedicado escasa atención a las consecuencias adversas de la DY durante la lactancia. En esta corta revisión, se examina la importancia del estado nutricional del yodo en la mujer lactante y se recomienda instaurar su vigilancia y monitoreo a través del análisis de yodo en orina, implementar medidas de intervención apropiadas a fin de contribuir a garantizar un óptimo estado de salud y nutrición en la madre y prevenir la aparición de trastornos por DY en lactantes y niños pequeños.

Iodine is an essential component of thyroid hormones (TH). TH are necessary for brain development. The most susceptible groups to iodine deficiency (ID) are pregnant and lactating women and children under two years of age. Maternal nutritional status and iodine intake strongly affect the amount of this nutrient secreted in breast milk (BM). Most of the iodine absorbed by the body is eventually excreted in the urine. For this reason, the median urinary iodine concentration (UIC) is the best indicator to assess the iodine nutritional status of lactating women and children less than two years of age. With base on the UIC in most of Latin American school-aged children, iodine intake was normal. However, iodine sufficiency in school age children not always corresponds with an adequate intake in lactating mothers. Little attention has been paid to the adverse consequences of ID during lactation. The objective of this short review was to examine the importance of iodine nutritional status in lactating women. We recommend to establish surveillance and monitoring of iodine status in lactating women through urine iodine levels, to implement measures to help promote an optimal health and nutrition of the mother to prevent iodine deficiency disorders (IDD) of infants and young children.

Surveillance and Analysis of Urinary Iodine Level in Pregnant Women in Xiaogan Prefecture / 国际检验医学杂志

Objective To monitor the level of urinary iodine in pregnant women in Xiaogan area,to understand the iodine nutri-tional status of pregnant women during pregnancy,and to provide theoretical basis for scientific guidance of iodine intake in preg-nant women.Methods The urine iodine levels of 2 956 pregnant women in Xiaogan Hospital Affiliated to Wuhan University of Sci-ence and Technology from March 2016 to May 2017 were examined and analyzed.Results In Xiaogan area,the median concentra-tions of urinary iodine in the early,middle and late stages of pregnant women were 145.73 μg/L,176.88 μg/L and 170.37 μg/L. 996 pregnant women were with urinary iodine concentration of over 150 μg/L,accounting for 33.69%;1372 pregnant women were with urinary iodine concentration of 150-249 μg/L,accounting for 46.41%;556 pregnant women were with urinary iodine concen-tration of 250-499 μg/L,accounting for 18.81%;32 pregnant women were with urinary iodine concentration of over 500 μg/L,ac-counting for 1.08%.The incidence rates of iodine deficiency in pregnant women at early,middle and late stage were 42.86%, 32.95% and 40.00%,and the difference was statistically significant(P<0.05).The incidence rate of iodine deficiency was 32.33%in pregnant women with age ≤ 30 years old,the incidence of iodine deficiency was 36.89% in pregnant women with age > 30 years old,and the difference was statistically significant(P<0.05).Conclusion At this stage,in Xiaogan,there are no overall maternal i-odine deficiency,but there was iodine malnutrition in pregnant women in early pregnancy,and some pregnant women lack awareness of iodine.

Iodine Status after a 3-Year Universal Salt Iodisation in Sarawak, Malaysia

Following the reveal of borderline iodine sufficiency among the Sarawakians from the 2008 National Iodine Deficiency Disorders (IDDs) survey, a mandatory universal salt iodization (USI) was implemented in Sarawak thereafter. This study aimed to determine the current status of USI in Sarawak after a 3-year implementation of USI from 2008 to 2011. The IDD survey was conducted between Jun 2011 to July 2011 involving six districts in Sarawak (Sarikei, Mukah, Kapit, Sibu, Bintulu and Miri). The schools were selected via multistage proportionate-to-population size sampling technique and the children were randomly selected via systematic sampling. A total of 19 schools and 661 children were recruited into the survey. Thyroid size was determined by palpation and was and graded according to the classification of the World Health Organization (grade 0-2). The iodine excretion level in spot morning urine was measured using in-house microplate method. The urinary iodine concentration (UIC) values were compared by Kruskal-Wallis test and Chi-square tests were used to compare categorical variables. A total of 610 school children were participated in the study (92.3%). The TGR of grade 1 and 2 was found to be 0.3% (n = 2). Overall the median UIC level was 154.2 (IQR, 92.7 - 229.8) µg/L, with the highest median UIC been observed in Sarikei [178.0 (IQR, 117.6 - 308.9) µg/L], followed by Mukah [174.8 (IQR, 99.0 - 224.3) µg/L)], Miri [158.6 (IQR, 92.3 - 235.4) µg/L], Sibu [147.0 (IQR, 89.8 - 221.4) µg/L], Bintulu [142.3 (IQR, 52.8 - 245.1) µg/L] and Kapit [131.0 (IQR, 88.6 - 201.9) µg/L]. One in every ten child was of iodine deficient (UIC < 50µg/L) while a third of the child (32%) were of adequate level of UIC. The present findings indicate that the mandatory USI successfully improves the iodine level of children in Sarawak. However, regular and proper monitoring of the UIC level in the communities is needed to prevent excessive iodine intake.​

Iodine Deficiency Disorder and Goitre among School Children in Sarawak -A Nationwide Study

Iodine deficiency disorders (IDD), is one of the most important micronutrient deficiencies which has multiple adverse effects on growth and development. The aim of this study was to determine the prevalence of IDD among school children and to elucidate the distribution of iodized salt at household level in Sarawak, East Malaysia. This cross-sectional study was conducted among school children aged 8 to 10 years in 2008. A multi-stage probability proportionate to population size (PPS) cluster sampling method was used to obtain a representative state sample of 1200 school children. Spot urine samples were collected for the determination of urinary iodine concentration while the iodine content in salt was determined using field rapid test kits. The thyroid status was determined by palpation. Response rate was 92.0% (n=1104/1200). The prevalence of goitre among school children in Sarawak was 2.9% (5.2% in urban, 0.7% in rural). The median urinary iodine concentration (UIC) among the school children was 102.1 µg/L (IQR, 62.3-146.5 µg/L). Urban children had significantly higher median UIC of 109.3 µg/L (IQR, 72.4-159.0 µg/L) than their rural counterparts [91.9 µg/L (IQR, 55.7-140.2 µg/L)]. The salt samples tested by rapid test kit (RTK) showed only 46.0% of household salt contained iodine. The present study revealed that the population in Sarawak were of borderline iodine sufficient with mild IDD seen in rural areas. Hence, the state IDD control programmes need to encourage and advocate the consumption of iodized salt in order to eliminate IDD-related health problems in Sarawak.

Iodine nutrition in elementary state schools of Queretaro, Mexico: correlations between urinary iodine concentration with global nutrition status and social gap index / Consumo de iodo em escolas de ensino fundamental de Querétaro, México: correlação entre a concentração urinária de iodo, o estado nutricional geral e o índice de desigualdade social

OBJECTIVE AND METHODS: To estimate median urinary iodine concentration (UIC), and to correlate it with global nutrition indicators and social gap index (SGI) in 50 elementary state schools from 10 municipalities in the State of Queretaro, Mexico. RESULTS: 1,544 students were enrolled and an above of requirements of iodine intake was found (median UIC of 297 µg/L). Iodine status was found as deficient, adequate, more than adequate and excessive in 2, 4, 19 and 25 schools, respectively. Seventy seven percent of table salt samples showed adequate iodine content (20-40 ppm), while 9.6% of the samples had low iodine content (< 15 ppm). Medians of UIC per school were positively correlated with medians of body mass index (BMI) by using the standard deviation score (SDS) (r = 0.47; p < 0.005), height SDS (r = 0.41; p < 0.05), and overweight and obesity prevalence (r = 0.41; p < 0.05). Medians of UIC per school were negatively correlated with stunting prevalence (r = -0.39; p = 005) and social gap index (r = -0.36; p < 0.05). Best multiple regression models showed that BMI SDS and height were significantly related with UIC (p < 0.05). CONCLUSIONS: There is coexistence between the two extremes of iodine intake (insufficient and excessive). To our knowledge, the observed positive correlation between UIC and overweight and obesity has not been described before, and could be explained by the availability and consumption of snack food rich in energy and iodized salt.

OBJETIVO E MÉTODOS: Estimar a concentração de iodo urinário (CIU) mediana e correlacioná-la com os indicadores de nutrição geral e com o índice de desigualdade social (IDS) de 50 escolas estaduais de ensino fundamental de 10 municípios do estado de Querétaro, no México. RESULTADOS: Utilizou-se um total de 1.544 crianças e encontrou-se uma ingestão acima das necessidades de iodo (CIU mediana de 297 µg/L). O nível de iodo determinado foi deficiente, adequado, mais do que adequado e excessivo em 2, 4, 19 e 25 escolas, respectivamente. Setenta e sete por cento de amostras de sal de mesa mostraram uma quantidade de iodo adequada (20-40 ppm), enquanto 9,6% das amostras tinham um teor de iodo baixo (< 15 ppm). As medianas de CIU por escola foram correlacionadas positivamente com as medianas do índice de massa corporal (IMC) usando o desvio-padrão da contagem (DP) (r = 0,47; p < 0.005), o DP da altura (r = 0,41; p < 0.05) e a prevalência de sobrepeso e de obesidade (r = 0,41; p < 0,05). As medianas de CUI por escola foram correlacionadas negativamente com a prevalência de desnutrição (r = -0.39; p = 005) e com o índice de desigualdade social (r = -0.36; p < 0,05). Os melhores modelos de regressão múltipla mostraram que a DP do IMC e a altura foram relacionados significativamente com a CIU (p < 0,05). CONCLUSÃO: Existe uma convivência entre os dois extremos de ingestão de iodo (insuficiente e excessiva). Em nosso conhecimento, a correlação positiva entre a CIU, o excesso de peso e a obesidade não foi descrita anteriormente e poderia ser explicada pela disponibilidade e consumo de alimentos ou refeições ricos(as) em energia e sal iodado.

Low Iodine Diet for Preparation for Radioactive Iodine Therapy in Differentiated Thyroid Carcinoma in Korea

Preparation for radioactive iodine (RAI) therapy includes an increased serum thyroid stimulating hormone level and a low iodine diet (LID). Because of extremely high iodine intake, some physicians have advocated a more stringent LID for greater than 2 weeks in Korean patients with thyroid cancer prior to RAI therapy; however, it is very difficult to maintain a stringent LID for a longer period of time. According to recent reports in Korea, a nonstringent, simple LID for only 1 week might be enough prior to RAI therapy, if the patients can be educated intensively by specially trained staff. The measurement of simple urinary iodine concentration (UIC; microg/L) may underestimate daily iodine excretion in patients with a urinary volume of more than 1 L/day and can also be affected by dilution status. Simple UIC had a weaker correlation than the iodine/creatinine (I/Cr) ratio. Therefore, the urinary I/Cr ratio can replace 24-hour urine iodine excretion instead of simple UIC, although it may overestimate iodine intake in patients with malnutrition or poor muscle mass. The measurement of serum iodine level might be useful as an adjunct parameter for assessing LID preparation, but its sensitivity and specificity were relatively low compared to the urinary I/Cr ratio.

Seaweed supplementation to prevent iodine deficiency.

Iodine is considered as one of the essential elements for the proper functioning of the hormones of human and animal thyroid glands. In many parts of the world iodine deficiency disorders develop because of deficiency of iodine in water and food supply. An iodine deficient goitrous mother may give birth to a cretinous baby because the fetus requires an adequate secretion of thyroxine during the later stages of pregnancy. Seaweed has such a large proportion of iodine compared to dietary minimum requirements, that it is primarily known as a source of this nutrient. A trial study on supplementation of iodine rich seaweed Caulerpa racemosa availed from Gujarat coast was conducted on iodine-deficient or thyroid-insufficient (n=10) pregnant women. They were supplemented daily with 0.17 g of algae in 20 g wheat flour ladoo for one month so as to provide 50μg/day of iodine and 0.343 mg/day of iron. A slight non-significant increase (104.75 to 121.05 μg/L) in median urinary iodine concentration (UIC) was observed after one month of supplementation. No significant effect of supplementation was observed on thyroid function parameters of the subjects. They also showed slight increase in hemoglobin level. Prolonged supplementation needs to be carried out further to opine on the impact of algae.