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Iodine, an essential trace element for the human body, plays a pivotal role in sustaining health. Malnutrition has emerged as a pressing public health concern, posing a significant threat to human well‐being. Iodine deficiency poses a substantial threat to the development of children, potentially leading to neurological developmental disorders and mental retardation. Conversely, excessive iodine intake can result in structural and functional abnormalities in the thyroid gland. In this study, we selected children aged 3–6 years through a stratified cluster sampling approach in six regions across China to explore the correlation between iodine nutrition and their physical growth. A total of 5920 preschool children participated in this study, with a median urinary iodine concentration (UIC) of 177.33 [107.06, 269.92] μg/L. Among these children, 250 (4.2%) exhibited stunting, 180 (3.0%) were underweight, 198 (3.3%) experienced wasting, 787 (3.3%) were overweight and 414 (7.0%) were classified as obese. The multivariate linear regression revealed that UIC exhibited a positive correlation with body mass index z‐Score (BMIZ) in overweight children (β = 0.038; 95% CI: 0.001, 0.075). In normally growing children, the associations between UIC and height‐for‐age z‐score, weight‐for‐age z‐score and BMIZ displayed nonlinear patterns. Our findings suggest that iodine nutrition is adequate for Chinese children aged 3–6 years. Furthermore, iodine nutrition is intricately linked to the growth and development of these children. Consequently, it is imperative to implement decisive measures to prevent both iodine deficiency and excess. Key messages: This paper is the first large‐scale nationwide epidemiological survey of iodine nutrition in preschool children in China.The median urinary iodine of preschool children in China was 177.33 [107.06, 269.92] μg/L, indicating adequate iodine nutrition.The study suggests that there may be a nonlinear correlation between median urinary iodine and physical growth indicators, such as height‐for‐age z‐score, in preschool children, with gender differences. [ABSTRACT FROM AUTHOR]

Abstract Iodine, an essential trace element for the human body, plays a pivotal role in sustaining health. Malnutrition has emerged as a pressing public health concern, posing a significant threat to human well‐being. Iodine deficiency poses a substantial threat to the development of children, potentially leading to neurological developmental disorders and mental retardation. Conversely, excessive iodine intake can result in structural and functional abnormalities in the thyroid gland. In this study, we selected children aged 3–6 years through a stratified cluster sampling approach in six regions across China to explore the correlation between iodine nutrition and their physical growth. A total of 5920 preschool children participated in this study, with a median urinary iodine concentration (UIC) of 177.33 [107.06, 269.92] μg/L. Among these children, 250 (4.2%) exhibited stunting, 180 (3.0%) were underweight, 198 (3.3%) experienced wasting, 787 (3.3%) were overweight and 414 (7.0%) were classified as obese. The multivariate linear regression revealed that UIC exhibited a positive correlation with body mass index z‐Score (BMIZ) in overweight children (β = 0.038; 95% CI: 0.001, 0.075). In normally growing children, the associations between UIC and height‐for‐age z‐score, weight‐for‐age z‐score and BMIZ displayed nonlinear patterns. Our findings suggest that iodine nutrition is adequate for Chinese children aged 3–6 years. Furthermore, iodine nutrition is intricately linked to the growth and development of these children. Consequently, it is imperative to implement decisive measures to prevent both iodine deficiency and excess.

Introduction: Iodine serves as a crucial precursor for the synthesis of thyroid hormones and plays an import role in both pregnant women and their offspring. The relationships between iodine nutritional status and maternal thyroid function and neonatal outcomes remain inconclusive in areas with adequate iodine nutrition. This study aims to investigate their correlations. Methods: Blood, morning urine and 24-hour urine were collected from the pregnant women to measure thyroid functions, serum iodine concentration (SIC), morning urine iodine concentration (UIC) and 24-hour urine iodine excretion (24-hour UIE). Indicators of their offspring’s neonatal indexes were recorded. Results: A total of 559 pregnant women were enrolled in this study. The iodine indicators including Tg, 24-hour UIE and morning UIC were significantly different among the euthyroid pregnant women and those with different thyroid disorders. The levels of FT3, FT4, and SIC exhibited a gradual decline and the concentration of TSH exhibited a gradual increase trend throughout the progression of pregnancy in euthyroid pregnant women. There were no significant differences in neonatal outcomes and neonatal TSH values among euthyroid pregnant women and thyroid disorders pregnant women. SIC had a significant impact on maternal FT4 levels throughout all three trimesters, with varying degrees of importance observed in each trimester. TSH level emerged as the primary determinant of FT4 during the first trimester, while SIC exerted a predominant influence on FT4 levels in the second and third trimesters. The prevalence of thyroid disorders in pregnant women was the lowest when the SIC of pregnant women was probable in the range of 60~70 μg/L, 24-hours UIE was in the range of 250~450 μg, and Tg was in the range of 9~21 μg/L. Maternal TSH exhibited a notable influence on neonatal TSH levels, particularly at the 50th and 75th quantiles. Among the iodine nutritional indicators, SIC and morning UIC demonstrated higher AUC values for abnormal FT4 and TSH, respectively. Discussion: The iodine nutrition status of pregnant women exerts an impact on their thyroid function and prevalence of thyroid disorders, and neonatal TSH was affected by maternal TSH. SIC may be a better indicator for iodine nutritional assessment than other indexes. [ABSTRACT FROM AUTHOR]

BackgroundPrevious iodine nutrition monitoring has mainly focused on key populations such as pregnant women and children, and there are few reports on the status of iodine nutrition among adults in Xinjiang. ObjectiveTo understand the iodine nutrition and thyroid function status of healthy adults in northern and southern Xinjiang, and to explore the effect of iodine nutrition level on thyroid function. MethodsIn May 2021, a stratified cluster sampling method was used to select one county (city) with good and one county (city) with poor economic conditions in each of the northern and southern regions of Xinjiang as the survey sites, and about 100 households were sampled from each survey site to collect samples of edible salt as well as random urine samples and fastingvenous blood of healthy adults aged 18 years or older. Urinary iodine was determined by cerium arsenide catalytic spectrophotometric method, salt iodine by direct titration method, and thyroid hormones by chemiluminescence immunoassay. Non-parametric test was used for comparison of non-normal quantitative data, t-test and analysis of variance were used for comparison of normal quantitative data, χ2 test was used for comparison of rates, and Spearman correlation analysis was used for correlation between salt iodine intake and urinary iodine level. ResultsA total of 436 salt samples were collected, the median salt iodine level was 28.18 mg·kg−1, and the coverage rate of qualified iodized salt was >90% in both northern and southern Xinjiang regions (P>0.05). A total of 436 adult urine samples were collected, the median urinary iodine was 219.73 μg·L−1. The urinary iodine medians of adults in the northern and southern regions were 209.47 μg·L−1 and 244.80 μg·L−1, respectively, and it was higher in the southern region than that in the northern region (P0.05), in which subclinical hypothyroidism was predominant, with prevalence rates of 9.95% and 9.36% in the northern and southern regions, respectively. ConclusionSome adults in northern and southern Xinjiang have high iodine nutrition levels, and although no significant effect has been found on thyroid function in the population, the high iodine nutrition status still requires continuing concern. It is recommended to monitor the iodine nutritional status of adults continuously while strengthening health education for residents.

ObjectiveTo examine iodine nutrition status among pregnant women in Ji'nan city, Shandong province for providing evidence to effective improvement of iodine nutrition in pregnant women. MethodsA monitoring survey was conducted among 4 992 pregnant women recruited in 12 districts/counties of Ji′nan municipality, Shandong province during 2018 – 2021; each of the districts/counties was divided into 5 geographical regions and 20 pregnant women were selected from one subdistrict/town in each of the 5 regions. Table salt samples were collected from households of the pregnant women and urine samples of the pregnant women were also collected. Iodine content of table salt samples was measured with direct titration listed in the General Test Method for Salt Industry: Determination of Iodine (GB/T13025.7) and that of well salt and other fortified table salt samples was determined with arbitration method. Urinary iodine was detected using arsenic cerium catalytic spectrophotometry stated in WS/T107 issued by National Health and Family Planning Commission. Year- and trimester-specific urinary iodine were analyzed. ResultsThe median ( 25% percentile [P25], 75% percentile [P75]) of iodine content was 22.31 (18.18, 25.59) mg/kg for all the 4 992 table salt samples. The coverage rate of iodized table salt was 88.92% (4 439 samples) and the usage rate of qualified iodized table salt was 72.96% (3 642 samples). There were significant yearly and regional differences in iodized salt coverage (χ2 = 72.54, χ2 = 271.04; both P < 0.05) and qualified iodized table salt usage rate (χ2 = 43.03, χ2 = 492.25, both P < 0.05); but the iodized salt coverage and qualified iodized table salt usage rate were not significantly different among the pregnant women in various trimesters of pregnancy (χ2 = 1.07, χ2 = 0.97; both P > 0.05). The median ( P25, P75) of urinary iodine was 145.70 (87.70, 216.00) μg/L for the 4 992 pregnant women. The urinary iodine concentration differed significantly among the pregnant women surveyed in different years (H = 21.97), from various districts/towns (H = 348.78), during various trimesters of pregnancy (H = 41.18), and consuming table salt with different iodine content (H = 13.23) (P < 0.05 for all). ConclusionMild iodine deficiency existed among pregnant women in Ji'nan city during 2018 − 2021, suggesting that relevant measures should be taken to prevent iodine deficiency in the pregnant women.

Background: Iodine deficiency is a major public health problem in pregnant women. Serum iodine (SI) may represent a useful biomarker for iodine nutrition evaluation. We aimed to assess the relationship between serum iodine concentration (SIC) and urinary iodine concentration (UIC), dietary iodine, thyroid function, and thyroid diseases in pregnant women in the southeast coast of China, and to provide a normal reference range of SIC for pregnant women. Methods: A multistage random sampling method was used to select the study population. We collected urine and blood samples from pregnant women and determined UIC and SIC as well as thyroid function using Arsenic-Cerium Catalytic Spectrophotometry, inductively coupled plasma mass spectrometry, and Beckman Coulter Access2 chemiluminescent immuno-analyzer and kit, respectively, and administered a questionnaire on dietary iodine intake in pregnant women. Results: There was a significant negative correlation between SI and thyroid stimulating hormone (TSH) (r = −0.141) and a significant positive correlation between SI and free triiodothyronine (FT3) (r = 0.106), free thyroxine (FT4) (r = 0.236), triiodothyronine (TT3) (r = 0.229), total thyroxine (TT4) (r = 0.433), and dietary iodine intake (r = 0.068). There was a significant difference in SI levels of pregnancy between the second (78.13 mg/L) and third trimester (75.37 mg/L) (p = 0.018). SI levels between inadequate intake (74.58 mg/L) and appropriate intake (77.92 mg/L) groups were statistically different (p = 0.036). Low SIC was a risk factor for the development of hypothyroxinemia (adjusted OR = 3.14, 95% confidence interval: 1.75–5.66). The reference range for SIC in normal pregnant women is 45.03–112.44 mg/L. Conclusion: SI may be a composite indicator of iodine nutritional status and thyroid function. [ABSTRACT FROM AUTHOR]

Objective: To investigate the adult iodine nutrition and the prevalence of thyroid diseases in Qinghai Province, and analyze the correlation between iodine and thyroid diseases, so as to provide a basis for adjusting the salt iodization plan in Qinghai Province. Methods: Using cluster and stratified sampling method to select 2628 permanent residents over 18 years old in Qinghai Province for questionnaire survey, physical examination, thyroid color ultrasound, and laboratory index detection. Results: 1. The coverage of iodized salt in adults is 99.71%. 2. The detection rates of thyroid disorders in adults were as follows: Clinical hyperthyroidism was 1.20%, subclinical hyperthyroidism was 0.20%, clinical hypothyroidism was 1.00%, subclinical hypothyroidism was 29.20%, and the goiter was 2.10%. The percentages positivity of TPO Ab, TG Ab, goiter was 9.80%, 9.20%, 2.10%, respectively. Among them single thyroid nodule was 6.40%, multi-nodule thyroid gland was 1.80%. 3. The percentages of mild iodine deficiency, moderate iodine deficiency, Severe iodine deficiency, adequate iodine intake (AI), more than adequate iodine intake (MAI)and excessive iodine intake (EI)were 8.41%, 2.17%, 0.26%, 33.22%, 28.35%, and 27.59%, respectively. The percentages of mild, moderate and severe iodine deficiency in urban populations (7.13%, 0.87%, 0.0%) were significantly lower than those in rural populations (9.81%, 3.59%, 0.56%) (P < 0.05), and the rates of adequate, more than adequate iodine intake in urban populations (36.03%, 30.93%) were significantly higher than that in rural populations (30.14%, 25.52%). The rate of excess iodine intake was higher in rural areas (30.38%) than in urban areas (25.04%). 4. The positive rates of subclinical hypothyroidism, goiter, TPO Ab and TG Ab in female adults (35.28%, 3.39%, 13.54%, 13.94%) were higher than those in male adults (23.58%, 0.96%, 6.266%, 4.79%). The detection rate of single thyroid nodules was higher in urban (8.01%) than rural populations (4.70%), while the detection rate of hypothyroidism, subclinical hypothyroidism, and goiter (0.58%, 25.84%, 1.38%) was lower than that in rural populations (1.52%, 32.96%, 2.96%) (P<0.05). 5. There was no statistical significance in the detection rates of clinical hyperthyroidism, subclinical hypothyroidism, subclinical hypothyroidism, goiter, thyroid nodules, TPO Ab and TG Ab positive rates in different iodine nutritional status (P>0.05). The positive rate of hypothyroidism in the iodine deficiency group is higher than in other iodine nutrition groups. Conclusion: The nutritional status of iodine in Qinghai Province is iodine excess. Subclinical hypothyroidism was detected at a high rate. Subclinical hypothyroidism, goiter, TPO Ab, and TG Ab were more common in female than in male. The proportion of mild, moderate, and severe iodine deficiency was higher in urban areas than in rural areas. The detection rate of thyroid nodules was higher in urban than in rural areas, and that of hypothyroidism, subclinical hypothyroidism, and goiter was lower than that in rural populations. The detection rate of clinical hypothyroidism was statistically significant in different iodine nutritional states (P< 0.05). [ABSTRACT FROM AUTHOR]

We aimed to investigate the association between iodine intake and nodal metastasis stratified by central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) of papillary thyroid microcarcinoma (PTMC). Urinary iodine concentration (UIC) and clinicopathological characteristics were used to identify factors associated with CLNM and LLNM using logistic regression analysis. A sum of 3,858 PTMC patients were enrolled. The median UIC (MUI) of patients with CLNM or LLNM was not statistically different from those without nodal metastasis. Male patients had a higher MUI than females (183.4 μg/L vs. 173.6 μg/L). Female patients with extracapsular extension had a higher MUI than those without it (210.0 μg/L vs. 172.1 μg/L). Male patients with LLNM had a significantly lower MUI than those without LLNM (134.7 μg/L vs. 187.9 μg/L). Female patients with more than adequate iodine intake were more likely to present with CLNM and extrathyroidal extension than those with adequate iodine intake with an odds ratio (95% confidence interval) of 1.23 (1.01-1.51) and 1.59 (1.09-2.32) after adjustment. Iodine nutrition was not found to be associated with LLNM. In addition, patients with a younger age, larger tumors, extrathyroidal extension, and intrathyroidal spread were more likely to be CLNM, whereas nodular goiter presented with a protective factor; CLNM was the only factor associated with LLNM of PTMC in both genders. In conclusion, iodine nutrition has a much closer association with female than male patients, and high iodine intake may be associated with CLNM and extrathyroidal extension in female PTMC patients. [ABSTRACT FROM AUTHOR]

Objective: To assess the iodine status and its associations with thyroid function in pregnant women of Shanghai. Methods: In this cross-sectional study, a total of 562 pregnant women were enrolled from January to December 2021. Both serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAB), thyroglobulin antibody (TGAB), and urinary iodine concentration (UIC) were detected. Participants were divided into four groups based on their UIC values. Correlation analysis was used to investigate the association between UIC and thyroid function-associated parameters. Results: The median UIC of the pregnant women studied was 158.25µg/L (interquartile range [IQR] 90.15, 245.65µg/L). Among all the subjects, 45.55% had iodine deficiency according to the World Health Organization (WHO) criteria, and 15.65% had thyroid autoimmunity. FT3, FT4, TSH, TPOAB and TGAB levels were not different among different UIC groups (P > 0.05). UIC and TSH were negatively correlated (r=-0.127, p=0.043) in UIC<150 µg/L group. In the group with UIC 250-499 µg/L, UIC was positively correlated with total T4 (TT4), total T3 (TT3) and TPOAB (r= 0.228, p=0.022, r=0.208, p= 0.039, r=0.190, p=0.042, respectively). A negative correlation between UIC and TPOAB values was observed in TPOAB-positive (+) pregnant women (r=-0.384, p=0.012). The prevalence of isolated hypothyroxinemia in UIC<150 µg/L group was significantly higher than that of other groups(p=0.033). The relationship between the prevalence of thyroid diseases and UIC embodied a U-shaped curve. Conclusion: Pregnant women on Chongming Island of Shanghai were iodine sufficient during the second trimester, but iodine deficiency was still prevalent. Both low and high gestational iodine status was related to thyroid function and autoimmunity. Optimal iodine nutrition status during gestation was important. [ABSTRACT FROM AUTHOR]

BACKGROUND:As iodine is a requisite micronutrient for infant brain development, infants are at risk for iodine deficiency during the weaning period when their diet transitions from milk (breast-milk, infant formula, or follow-on formula) to solid food. Dietary iodine intake during this weaning period is likely minimal, as the iodine content of commercial baby food is not regulated, and the addition of salt to baby food is not recommended. This study reports the current status of iodine nutrition among weaning infants in the United States. METHODS:Subjects (n = 60; 50% Caucasian, 30% black) were infants

Southern Xinjiang has a history of serious iodine deficiency. Since 2007, pregnant women in this area have taken iodized salt and oral lipiodol preparations to prevent iodine deficiency disorders. However, the current status of iodine nutrition and thyroid function in this population is unknown. A cross-sectional study was conducted on 555 pregnant women from 5 counties (cities) in southern Xinjiang and 429 pregnant women from 3 counties in northern Xinjiang. The participants were given a questionnaire and serum concentrations of free triiodothyronine (FT3), free thyroxine (FT4), thyrotropic stimulating hormone (TSH), thyroglobulin antibody (Tg-Ab), and thyroid peroxidase antibody (TPO-Ab), and the urine iodine concentration (UIC) was measured. The median UIC and interquartile range [M (IQR)] of the 984 pregnant women in the study was 189.38 (143.15, 288.77) μg/L. Positive Tg-Ab and TPO-Ab titers were detected in 6.74% and 9.55%, 8.30% and 9.84%, and 7.39% and 10.55% in T1, T2, and T3, respectively. The incidence of subclinical hypothyroidism, clinical hypothyroidism, and isolated hypothyroxinemia in pregnant women in areas where lipiodol pills were taken was 4.32%, 0%, and 1.44%, respectively, which was significantly lower than those in areas where lipiodol pills were not taken. The median UIC (IQR) of pregnant women in the two regions was 213.80 (130.44, 331.77) μg/L and 168.30 (155.0, 254.8) μg/L, the UIC of pregnant women who took lipiodol pills was higher than in those who did not take lipiodol pills, and the difference was statistically significant (p < 0.05). According to WHO standards, all pregnant women in southern Xinjiang are in a state of adequate iodine nutrition. Taking lipiodol pills has improved the iodine nutrition level of pregnant women in this area. The results of this study did not find that oral lipiodol pills had adverse effects on pregnant women's thyroid function, but it is necessary to further study the effect of oral lipiodol pills on the offspring. [ABSTRACT FROM AUTHOR]

ObjectiveTo investigate the status of maternal iodine deficiency in Lishui City of Zhejiang Province， and explore the effect of maternal iodine deficiency on the growth and development of infants.MethodsA total of 209 pregnant women living in Liandu District of Lishui City from January 2017 to December 2018 were selected by stratified sampling method. Urine iodine level in pregnant women and iodine content in edible salt at home were determined to assess the status of iodine deficiency and to analyze the influencing factors. Their babies were followed up for 1 year， and metabolic disease screening and physical examination were carried out to evaluate the growth and development.ResultsThe median of urinary iodine levels in 2017 and 2018 were 165 µg·L-1 and 192 µg·L-1， respectively. Both of the values met the standard of iodine sufficiency. The results of salt iodine content in pregnant women's homes showed that 7 cases （3.35%） were without iodized salt and 202 cases （96.65%） with iodized salt， including 186 cases （89.00%） with qualified iodized salt. Univariate analysis showed that pregnancy， education level， intake of iodized salt， cooking methods of salt， intake frequency of iodine-rich food and knowledge of iodine nutrition had significant impact on iodine deficiency in pregnant women （P

Background: The effect of iodine on papillary thyroid cancer (PTC) has been controversial for many years. Since urinary iodine is an effective indicator of iodine intake, some recent epidemiological studies have described the relationship between urinary iodine concentration (UIC) and PTC. Methods: We searched PubMed, Embase, Cochrane Library, and Web of Science for case-control studies about UIC and PTC published before September 2022. Results are presented as the overall odds ratio (OR) and 95% confidence intervals (CI). Results: According to the analysis of the included studies, excessive iodine intake (UIC=300ug/L) was positively associated with the occurrence of PTC patients compared with healthy controls (OR4.05, 95%CI 1.64-10.02, P=0.002). Meanwhile, adequate iodine exposure (100=UIC<200ug/L) may play a protective role in the occurrence of PTC compared with healthy individuals (OR 0.36, 95%CI 0.14-0.91, P=0.03) while the difference in the prevalence of insufficient iodine intake (UIC<100ug/L) and iodine above requirements (200=UIC<300ug/L) among the two groups were not significant (deficiency: OR 0.38, 95%CI 0.13-1.16, P=0.09; above requirements: OR 0.92, 95%CI 0.40-2.10, P=0.84). After comparing the UIC levels of PTC patients with those of other thyroid diseases, we found that there was also no significant difference in the incidence of different levels of UIC in the two groups (excessive: OR 1.25, 95%CI 0.87-1.80, P=0.22; above requirements: OR 0.93, 95%CI 0.77-1.14, P=0.49; adequate: OR 0.96, 95%CI 0.78-1.17, P=0.67; deficiency: OR 1.02, 95%CI 0.86-1.22, P=0.80). The result of this meta-analysis also did not support the relationship between UIC and the BRAF mutation and lymph node metastasis (LNM) of PTC patients. Besides, we also found that studies on the relationship between urinary iodine and PTC may be influenced by the way UIC was measured. Conclusion: The 10 case-control included studies involved a total of 6,544 participants. The results of this meta-analysis showed excessive iodine intake, that is, UIC=300ug/L was associated with the occurrence of PTC but not with BRAF mutation and LNM while adequate iodine intake (100=UIC<200ug/L) may be one of the protective factors for PTC. [ABSTRACT FROM AUTHOR]

Iodine is a micronutrient that is required for thyroid hormone synthesis. The iodide cycle in thyroid hormone synthesis consists of a series of transport, oxidation, organification, and binding/coupling steps in thyroid follicular cells. Common sources of iodine include the consumption of an iodine-rich diet or iodine-fortified foods, the administration of amiodarone, iodine-containing supplements, or iodinated contrast media, and other miscellaneous sources. Methods to assess population iodine status include the measurement of urinary iodine concentrations, blood thyroglobulin levels, prevalence of elevated neonatal thyrotropin levels, and thyroid volume. Although excessive iodine intake or exposure is generally well tolerated, an acute iodine load may result in thyroid dysfunction (hypothyroidism or hyperthyroidism) in certain susceptible individuals due to the failure to escape from the Wolff-Chaikoff effect and to the Jod-Basedow phenomenon, respectively. In this review, we discuss the associations between excessive iodine intake or exposure, with particular focus on iodinated contrast media as a common source of excess iodine in health care settings, and risks of incident thyroid dysfunction. We also summarize the risks of iodine excess in vulnerable populations and review current guidelines regarding the screening and monitoring of iodinated contrast-induced thyroid dysfunction. Finally, we discuss the long-term potential nonthyroidal health risks associated with iodine excess and suggest the need for more data to define safe upper limits for iodine intake, particularly in high-risk populations., (Published by Oxford University Press on behalf of the Endocrine Society 2024.)

Thyroid cancer (TC) is the most frequent endocrine malignancy. The incidence of TC, especially papillary thyroid carcinoma (PTC), has continued to rise all over the world during the past few years, for reasons that are not entirely clear. Though the phenomenon of overdiagnosis is occurring, it is not the sole driver of the substantial increase in incidence. Lifestyle, environmental factors, or complications are considered to be potential risk factors. Among these factors, iodine is a micronutrient that is vital to thyroid function. The effect of iodine intake on PTC has been controversial for many years and the epidemiological or experimental studies provided diametrically opposite conclusions. Combining all these studies, we found that iodine nutrition may affect the overall prevalence, distribution of the histological types, and clinicopathological aggressiveness of TC, especially PTC. However, the available evidence is poor due to the impact of various internal and external related factors. Therefore, this article sums up available results from both epidemiological and experimental studies, future studies are also warranted to expound on the relationship between overall PTC prevalence and iodine intake.

BackgroundIodine is an essential micronutrient for thyroid hormone production. Adequate iodine intake and normal thyroid function are important during early development, and breastfed infants rely on maternal iodine excreted in breast milk for their iodine nutrition. The proportion of women in the United States of childbearing age with urinary iodine concentration (UIC)

Purpose: Mild-to-moderate iodine deficiency was present in large parts of Germany up to the beginning 1990s and improved from then on. Current epidemiological data on spot urine iodine measurements in German children strongly suggest the re-occurrence of an impaired iodine status. We thus examined whether this re-occurrence is identifiable in more detail, through iodine analyses of 24-h urine samples of a well-characterized cohort of German children in whom samples have been systematically collected from 1985 onward. As iodized salt is a major source for iodine supply, urinary sodium excretion was additionally studied. Methods: Daily iodine and sodium excretions were measured in 2600 24-h urine samples collected between 1985 and 2018 by 677 healthy children aged 6–12 years (participants of the DONALD study). These data were compared with 24-h iodine and sodium excretion estimates obtained from spot urine samples collected in the representative German Health Interview and Examination Surveys for Children and Adolescents KiGGS-baseline (2003–2006) and KiGGS-wave-2 (2014–2017). Results: Between 1985 and1992, DONALD participants started with a median daily iodine excretion level of 40.1 µg/d. Then, during 1993–2003, iodine excretions mounted up to an approximate plateau (~ 84.8 µg/d). This plateau lasted until 2012. Thereafter, iodine concentrations started to decrease again resulting in a median iodine excretion of only 58.9 µg/d in 2018. Sodium excretion, however, had increased. The marked decrease in iodine status along with an abundant sodium excretion corresponded closely with nationwide KiGGS data. Conclusions: As exemplified for the clearly worsening iodine status in German children, longitudinal cohort studies collecting detailed biomarker-based prospective data have the potential to reliably capture health-relevant nutritional changes and trends, applicable on a more comprehensive and even representative population level. [ABSTRACT FROM AUTHOR]

Purpose: There is some uncertainty about the optimal ranges for urinary iodine concentration (UIC) during pregnancy. This study aimed to explore associations between maternal UIC and thyroid function in iodine sufficient and mildly iodine deficient areas. Methods: It was a cross-sectional study in which 1461 healthy pregnant women were enrolled to collect their blood and urine samples during their routine antenatal care in Tianjin and Wuqiang, China. Wuqiang was a mildly iodine-deficient region, while Tianjin was iodine sufficient. UIC, free triiodothyronine (FT3), free thyroid hormone (FT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), serum iodine concentration (SIC) including total serum iodine concentration (tSIC) and non-protein bound serum iodine concentration (nbSIC) were assessed during the routine antenatal care visits. Results: The median UIC in pregnant women was 174 (113, 249) μg/L in Tianjin and 111 (63, 167) μg/L in Wuqiang, respectively. Compared with Tianjin, UIC, FT3 and TSH were lower, and FT4, tSIC, nbSIC, rates of TPOAb and TgAb positivity and the thyroid dysfunction rate (TDR) were higher in Wuqiang (P < 0.001). FT3, FT4, tSIC and nbSIC increased during pregnancy in Tianjin with increasing UIC, while only FT3 and nbSIC increased in Wuqiang (P < 0.05). In Tianjin, the TDR increased with UIC and peaked at UIC ≥ 500 μg/L (P = 0.002), while in Wuqiang, the TDR showed a weak "U-shaped" relationship with UIC and the rate was lowest with UIC 100–149 μg/L. Conclusions: In iodine-deficient areas, there was a lower TDR in pregnant women with UIC 100–149 μg/L. We suspected that the optimal UIC criteria recommended by WHO may be a little high for pregnant women in mild-to-moderate iodine-deficient countries. [ABSTRACT FROM AUTHOR]

Objective: To explore the accuracy of estimated 24-h urinary iodine excretion (24-h UIEest) in assessing iodine nutritional status.Design: Fasting venous blood, 24-h and spot urine samples were collected during the day. The urinary iodine concentration (UIC) and urinary creatinine concentration (UCrC) were measured, and the urinary iodine-to-creatinine ratio (UI/Cr), 24-h UIEest, and 24-h urinary iodine excretion (24-h UIE) were calculated. At the population level, correlation and consistency between UIC, UI/Cr, 24-h UIEest and 24-h UIE were assessed using correlation analysis and Bland-Altman plots. At the individual level, receiver operating characteristic (ROC) curves were used to analyse the accuracy of the above indicators for evaluating insufficient and excessive iodine intake. The reference interval of 24-h UIEest was established based on percentile values.Setting: Indicator can accurately evaluate individual iodine nutrition during pregnancy remains controversial.Participants: Pregnant women (n 788).Results: Using 24-h UIE as standard, the correlation coefficients of 24-h UIEest from different periods of the day ranged from 0·409 to 0·531, and the relative average differences ranged from 4·4 % to 10·9 %. For diagnosis of insufficient iodine intake, the area under the ROC curve of 24-h UIEest was 0·754, sensitivity and specificity were 79·6 % and 65·4 %, respectively. For diagnosis of excessive iodine intake, the area of 24-h UIEest was 0·771, sensitivity and specificity were 66·7 % and 82·0 %, respectively. The reference interval of 24-h UIEest was 58·43-597·65 μg.Conclusions: Twenty-four-hour UIEest can better indicate iodine nutritional status at a relatively large sample size in a given population of pregnant women. It can be used for early screening at the individual level to obtain more lead time for pregnant women. [ABSTRACT FROM AUTHOR]

Abstract Background Although iodine nutrition status is improving globally, the progress is not uniform throughout the world due to several factors. Among these, poor knowledge, negative attitude and improper practice of iodized salt are the main risk factors for poor iodine nutrition in Ethiopia. This study was aimed to assess the effect of nutrition education intervention on knowledge, attitude and practice (KAP) of iodine deficiency and iodized salt utilization. Methods A cluster randomized controlled trial was carried out among 652 women of reproductive age group in southwest Ethiopia. A total of 24 clusters were selected and randomized in to an intervention and control villages. Women in the intervention village received iodine nutrition related education for 6 months; while those in the control village did not receive any education. Baseline and endline data were collected from both groups. Generalized Estimating Equations (GEE) was used to determine the effect of intervention. Results A total of 647 (99.2%) participants were successfully involved in the study. In the intervention group the median attendance was 10 out of 12 sessions. Women in the intervention group had shown statistically significant change in knowledge, attitude and practice scores as compared to control one. In multivariable GEE linear model, after adjusting for other background characteristics, the mean difference (95% CI) scores were 8.81 (8.46, 9.16) for knowledge, 3.35 (3.17, 3.54) for attitude and 2.90 (2.74, 3.05) for practice in the intervention arm. Conclusions Well designed and community-based iodine nutrition education is an effective strategy to improve the KAP of iodine deficiency disorders and iodized salt utilization. Trial registration PACTR201809544276357 (Retrospectively registered on 14, Sept. 2018). https://www.pactr.org .

Objective: The remarkable success of iodine deficiency disorders (IDD) eli mination in China has been achieved through a mandatory universal salt iodi zation (USI) program. The study aims to estimate the relationship between urinary iod ine concentration (UIC) and iodine content in edible salt to assess the current iodine nutritional status of school aged children. Methods: A total of 5565 students from 26 of 39 districts/counties in Chongqing participated in the study, UIC and iodine content in table salt were measured. Thyroid volumes of 3311 students were examined by ultrasound and goiter prevalence was calculated. Results: The overall median UIC of students was 222 μg/L (IQR: 150-313 μg/L). Median UIC was significantly different among groups with non-iodized salt (i odine content 39 mg/kg) salt (P < 0.01). The total goiter rate was 1.9% (60/3111) and 6.0% (186/3111) according to Chinese nationa l and WHO reference values, respectively. Thyroid volume and goiter prevalence were not different within the three iodine nutritional status groups (insufficient, adequate an d excessive, P > 0.05). Conclusions: The efficient implementation of current USI program is able to r educe the goiter prevalence in Chongqing as a low incidence of goiter in school aged children is observed in this study. The widened UIC range of 100–299 μg/L indicating sufficient iodine intake is considered safe with a slim chance of causing goiter or thyroid dysfunction. Further researches were needed to evaluate the applicability of WHO reference in goiter diagnose in Chongqing or identifying more accurate criteria of normal thyroid volume of local students in the future.

Epidemiological studies have focused on the effects of iodine intake on the risk of thyroid cancer. However, their relationship is still obscure. The objective of the present study was to examine the association in the Chinese population. A new ecological study which combined the Data of Annual Report of Cancer, the Survey of Iodine Deficiency Disorders (IDD) surveillance and the Water Iodine Survey was conducted to analyse the relationship between iodine intake and the thyroid cancer incidence in China. In total, 281 counties were included. Thyroid cancer incidence was negatively correlated with the consumption rate of qualified iodised salt (CRQIS) and positively correlated with goiter prevalence (GP) of children aged 8–10 years, residents' annual income and coastal status. Areas with a low CRQIS and areas with a high GP had a relatively high incidence of thyroid cancer. Regression models showed that a low CRQIS and a high GP in children aged 8–10 years (both reflecting iodine deficiency status) play a substantial role in thyroid cancer incidence in both males and females. Additionally, living in coastal areas and having a high annual income may also increase the risk of thyroid cancer. These findings suggest that mild iodine deficiency may contribute to the exceptionally high incidence of thyroid cancer in some areas in China. Maintaining appropriate iodine nutrition not only helps to eliminate IDD but also may help to reduce the occurrence of thyroid cancer. [ABSTRACT FROM AUTHOR]

Lack of knowledge about iodine has been suggested as a risk factor for iodine deficiency in pregnant women, but no studies have addressed this issue in Portugal. So, the aim of this study was to investigate iodine knowledge among Portuguese pregnant women and its association with iodine status. IoMum, a prospective observational study, included 485 pregnant women recruited at Centro Hospitalar e Universitário de S. João, Porto, between the 10th and 13th gestational weeks. Partial scores for knowledge on iodine importance, on iodine food sources or on iodised salt were obtained through the application of a structured questionnaire. Then, a total iodine knowledge score was calculated and grouped into low, medium and high knowledge categories. Urinary iodine concentration (UIC) was measured in spot urine samples by inductively coupled plasma MS. Of the pregnant women, 54 % correctly recognised iodine as important to neurocognitive development, 32 % were unable to identify any iodine-rich food and 71 % presented lack of knowledge regarding iodised salt. Of the women, 61 % had a medium total score of iodine knowledge. Knowledge on iodine importance during pregnancy was positively associated with iodine supplementation and also with UIC. Nevertheless, median UIC in women who correctly recognised the importance of iodine was below the cut-off for adequacy in pregnancy (150 µg/l). In conclusion, knowledge on iodine importance is positively associated with iodine status. Despite this, recognising iodine importance during pregnancy may not be sufficient to ensure iodine adequacy. Literacy-promoting actions are urgently needed to improve iodine status in pregnancy. [ABSTRACT FROM AUTHOR]

The work reported in this paper addresses the iodine nutritional deficiency that still affects a large number of people. For this purpose, we analyzed the possibility to use, as iodine vehicle, a hard typical ewe cheese, called Canestrato d'Abruzzo, derived from milk of ewes fed with an iodine-fortified diet. Both in the milk and the cheese of these animals, the iodine level was higher than that measured in sheep with a normal diet. An increase in the lactoferrin and iron content was evident in the whey derived from milk of the iodine group. Furthermore, in derived cheese, the caseins seemed more efficiently transformed in small peptides making the product more digestible and, for this reason, particularly suitable for feeding the elderly. In conclusion, the dairy products obtained from ewes fed with iodine diet contain more bioactive compounds so that they represent a useful food to prevent iodine and iron deficiency in lamb and humans. [ABSTRACT FROM AUTHOR]

Objective To understand the iodized salt consumption and the status of iodine nutrition of pregnant women and children in Jiulongpo District of Chongqing,and provide evidence for scientific iodine supplementation.Methods From 2018 to 2020,according to the"Iodine Deficiency Surveillance Program of Chongqing",Jiulongpo District was divided into five sampling areas,the East,West,South,North and Central.Pregnant women and children aged 8 to 10 years were collected from each sampling area,whose urine samples and household salt samples were collected to detect the urine iodine and salt iodine content.Results A total of1 106 salt samples were collected,including 1 096 iodized salts and 1 084 qualified iodized salts.The iodized salt coverage rate was 99.10%,and the consumption rate of qualified iodized salt was 98.01%.A total of 766 urine samples of children were collected,and the median urinary iodine was 256.2μg/L.From 2018 to 2020,the proportion of children urine iodine greater than or equal to 300μg/L were 19.67%,29.01%and 38.49%,which was increased year by year（trendχ2=4.636,P<0.001）.Urine iodine of girls（246.0μg/L）was less than boys（269.6μg/L）,which was statistically significant（H =12.438,P<0.001）.A total of 340 urine samples were collected from pregnant women,and the median urinary was 200.2μg/L.There was no significant difference in urinary iodine of pregnant women among years（H =0.434,P=0.805）.Conclusion The popularity of iodized salt is high in Jiulongpo District in Chongqing.Urinary iodine of pregnant women and children is at an appropriate level.It is suggested to carry out scientific publicity and education of iodine supplementation and strengthen the monitoring of iodine nutrition in children′s diet. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the iodine nutritional status and the epidemiological characteristics of thyroid nodules (TNs) in the adult population of Heilongjiang Province. From December 2017 to December 2018, a total of 3661 adults aged 20–70 years were selected through probability proportional to size (PPS) sampling for a cross-sectional survey. During the field epidemiological investigation, each participant received a questionnaire survey and thyroid ultrasonography examination. The iodine concentrations in casual urine specimens and household edible salt were measured. The household coverage of iodized salt was 86.56%. The median urinary iodine concentration (MUIC) in the adult population in Heilongjiang Province was 161.57 μg/L (25th–75th percentile: 100.35–245.15 μg/L). The prevalence of TNs was 36.88%, and the prevalence in females was significantly higher than that in males (41.25% vs 32.50%, χ2 = 11.841, P < 0.01). The prevalence of TNs increased with age (χ2trend = 49.80, P < 0.001). The prevalence of multiple TNs increased with age (χ2trend = 48.709, P < 0.001). There was no significant difference in the MUIC between healthy control group and those with TNs (Z = − 1.386, P = 0.166). The female, age (40–49 age group, 50–59 age group, 60–70 age group), BMI (obesity, overweight), history of hypertension, history of diabetes, and smoking history were all independent risk factors that affected the occurrence of TNs. The iodine nutritional status of the adult population in Heilongjiang Province was adequate. The prevalence of TNs was higher in middle-aged and elderly women, so these individuals should be the focus of the prevention and treatment of thyroid nodule disease. [ABSTRACT FROM AUTHOR]

The discussion in this column is not about legislation but about issues that are closer to the readership. What products mainly provide for the need of the human body in iodine in Russia and other (near and far) countries of the world? For example, is there such a substance as an optimal thyroid diet and how can it be achieved both by healthy people and patients with thyroid disorders? Unlike North America, Australia and New Zealand, the Scandinavian and some other European countries, dairy products are not the main sources of iodine in the diet of the Russian population. There are not so many of these sources, let alone their availability and price. Even the high iodine content in feijoa is proven fake. And what will happen to our thyroid diet, when, finally, Russia will adopt a law on mandatory salt iodization? If everything goes as planned, in a few years, bakery products will become the main source of iodine in our diet, and the daily intake of iodine due to the use of iodized salt in baking will increase by an average of 80100 mcg per day. Then the dream of an optimal thyroid diet will come true even without expensive seafood and amazing feijoa.

Rui Ren,1,2 Yu Ma,2 Fang Deng,1 Tao Li,1 Hongyan Wang,2 Jing Wei,3 Xiaoyan Jiang,2 Min He,1 Mingyuan Tian,4 Dongfang Liu,4 Bing Chen,1 Wuquan Deng1,21Department of Endocrinology and Nephrology, Chongqing University Central Hospital, Chongqing Emergency Medical Center, Chongqing, People’s Republic of China; 2Department of Endocrinology, Southwest Hospital, Army Medical University, Chongqing, People’s Republic of China; 3Department of Endocrinology, General Hospital of Xinjiang Military Region, PLA, Urumqi, People’s Republic of China; 4Department of Endocrinology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, People’s Republic of ChinaCorrespondence: Wuquan DengDepartment of Endocrinology and Nephrology, Chongqing University Central Hospital, Chongqing Emergency Medical Center, No. 1 Jiankang Road, Yuzhong District, Chongqing, People’s Republic of ChinaTel +86 236 369 2185Email wuquandeng@gmail.comBackground: Whether a relationship exists between various metabolic factors and thyroid-stimulating hormone (TSH) levels in euthyroid persons remains unknown. This study aims to explore the relationship between TSH levels and metabolic factors in euthyroid individuals.Methods: A total of 2,663 subjects were enrolled from a nationwide population-based cross-sectional survey of iodine nutrition, thyroid disease and diabetes in China (2014–2017). Euthyroid individuals were divided into four groups according to quartiles of TSH levels: group A (n=305, 0.3–1.3 mIU/L), group B (n=829, 1.3–2.2 mIU/L), group C (n=673, 2.2–3.2 mIU/L) and group D (n=349, 3.2–4.2 mIU/L). Anthropometric parameters, biochemical indicators and TSH levels were determined.Results: A total of 2,156 euthyroid subjects with serum TSH levels within the normal range accounted for 86.8% of the sample. The systolic blood pressure (SBP) in group D was significantly higher than that in the other three groups. Group C displayed significantly lower thyroid peroxidase antibody (TPOAb) levels than the other three groups. Group C also had lower anti-thyroglobulin antibody (TgAb) levels than groups A and D, whereas the TgAb levels in group B were only lower than those in group A. Spearman’s or Pearson’s linear regression analysis showed that SBP (r=0.054; P=0.013) was positively correlated with TSH, but cholesterol (TC) (r=−0.043, P=0.047) was negatively correlated with TSH. Multiple stepwise regression analysis revealed that SBP, the urinary iodine concentration (UIC), waist circumference (WC), body mass index (BMI), TC, triglycerides (TGs) and low-density lipoprotein cholesterol (LDL-C) were independent predictors of serum TSH levels.Conclusion: This large population-based study demonstrates a significant interaction between metabolic factors and TSH levels. An adverse weight status, high blood pressure levels, blood lipid metabolism disorder and excessive iodine intake may be early manifestations of thyroid disease in euthyroid subjects.Keywords: thyroid-stimulating hormone, metabolic syndrome, iodine nutrition, euthyroid state

Purpose: Salt iodization in Manipur of north-east India failed to prevent endemic goiter, therefore an in depth study carried out to evaluate thyroid functions of goitrous subjects in a randomly selected region. Methods: Goiter survey conducted in children and women of reproductive ages by palpation followed by measurement of urinary iodine, thiocyanate and house-hold salt iodine to evaluate iodine nutritional status and consumption pattern of bamboo-shoots (BS). In all grade-2 goitrous subjects, free thyroxine, triiodothyronine, TSH, TPO and Tg antibodies, thyroid volume and echogenecity by ultrasonography and cytomorphology of thyroid by FNAC studied. Results: Study population was 2486 children and 1506 women, goiter prevalence was 12.59% and 16.27% respectively; median urinary iodine and mean thiocyanate were 166 µg/l and 0.729 ± 0.408 mg/dl while salt iodine was ≥30 ppm. Serum thyroid hormones and TSH profiles of all grade-2 goitrous subjects showed 16.21% were subclinically hypothyroid, 2.16% overt hypothyroid, 4.86% subclinically hyperthyroid and 6.48% overt hyperthyroid, serum TPO- and Tg-antibodies found positive in 41.62%. Ultrasonographic results showed 24% had enlarged thyroid and 86.4% hypoechoic. Cytomorphological studies showed prevalence of colloid goiter (41.08%), lymphocytic thyroiditis (37.83%), Hashimoto’s thyroiditis (8.10%), autoimmune thyroiditis (4.32%), sub-acute thyroiditis (2.16%) and 1.62% each papillary, medullary carcinoma, simple diffused hyperplasia and adenomoid nodular goiter. Conclusions: Grade-2 goitrous individuals in this mild goiter endemic region were affected by hypo- and hyperthyroidism with hypoechoic thyroid and thyroiditis. Thiocyanate that originates from BS even in presence of adequate iodine developed goiter and led goitrous population towards such diseases.

Objective To investigate the puberty development，iodine nutrition and thyroid function，and to explore their association among school-aged girls in Minhang District，Shanghai. Methods From Jan to Mar 2019，a cluster sampling method was used to select 6 junior high schools in the east，south，north, and middle areas in Minhang District，Shanghai. A total of 532 girls of Grade 6 in selected schools were included in the study.Physical examination was conducted，and their urine and blood samples were collected to determine urinary iodine concentration（UIC）and thyroid functions.Pubertal Development Scale（PDS） was used to define the pubertal stage.Multiple linear regression models and Logistic regression models were conducted to analyze the associations between puberty stage and thyroid functions. Results A total of 513 participants met the criteria and had complete data.Most of the participants were in pubertal stage 4， accounting for 47.17%（242/513），The urinary iodine on Thursday（median：172 μg/L）was significantly higher than that on Monday（median：134 μg/L）（P<0.01），and the weighed urinary iodine excretion was significantly different in girls with different pubertal stage（P=0.025）.After adjusting for the iodine nutrition status，for each one point increase in PDS score，triiodothyronine（TT3），tetraiodothyronine（TT4）and free triiodothyronine（FT3） decreased by 0.47，0.01 and 0.10 nmol/L，respectively. For each one level increase in puberty stage，TT3，TT4 and FT3 decreased by 0.26，0.01 and 0.09 nmol/L，respectively.Girls in post-puberty had the lower levels of TT3（OR=0.57，95%CI：0.34-0.95），TT4（OR=0.54，95%CI： 0.32-0.92）and FT3（OR=0.53，95%CI：0.31-0.90）as compared with girls in pre-puberty. The levels of TT3（OR=0.52，95%CI：0.35-0.77）and FT3（OR=0.55，95%CI：0.37-0.81）were significantly lower in girls after menarche than those without menarche. Conclusion There is anassociation between pubertal stage and thyroid functions in school-aged girls during puberty in Minhang District，Shanghai.TT3，TT4， and FT3 levels decline with the process of puberty. [ABSTRACT FROM AUTHOR]

Iodine intake affects the occurrence of thyroid disorders. However, the association of iodine intake with longevity remains to be described. This led us to perform a 20 years' follow-up on participants from the Randers–Skagen (RaSk) study. Residents in Randers born in 1920 (n 210) and Skagen born in 1918–1923 (n 218) were included in a clinical study in 1997–1998. Mean iodine content in drinking water was 2 µg/l in Randers and 139 µg/l in Skagen. We collected baseline data through questionnaires, performed physical examinations and measured iodine concentrations in spot urine samples. Income data were retrieved from Danish registries. We performed follow-up on mortality until 31 December 2017 using Danish registries. Complete follow-up data were available on 428 out of 430 of participants (99·5 %). At baseline, the median urinary iodine concentration was 55 µg/l in Randers and 160 µg/l in Skagen residents. Participants were long-term residents with 72·8 and 92·7 % residing for more than 25 years in Randers and Skagen, respectively. Cox regression showed that living in Skagen compared with Randers was associated with a lower hazard ratio (HR) of death in both age- and sex-adjusted analyses (HR 0·60, 95 % CI 0·41, 0·87, P = 0·006), but also after adjustment for age, sex, number of drugs, Charlson co-morbidity index, smoking, alcohol and income (HR 0·60, 95 % CI 0·41, 0·87, P = 0·008). Residing in iodine-replete Skagen was associated with increased longevity. This indicates that long-term residency in an iodine-replete environment may be associated with increased longevity compared with residency in an iodine-deficient environment. [ABSTRACT FROM AUTHOR]

Introduction: Iodine serves as a crucial precursor for the synthesis of thyroid hormones and plays an import role in both pregnant women and their offspring. The relationships between iodine nutritional status and maternal thyroid function and neonatal outcomes remain inconclusive in areas with adequate iodine nutrition. This study aims to investigate their correlations., Methods: Blood, morning urine and 24-hour urine were collected from the pregnant women to measure thyroid functions, serum iodine concentration (SIC), morning urine iodine concentration (UIC) and 24-hour urine iodine excretion (24-hour UIE). Indicators of their offspring's neonatal indexes were recorded., Results: A total of 559 pregnant women were enrolled in this study. The iodine indicators including Tg, 24-hour UIE and morning UIC were significantly different among the euthyroid pregnant women and those with different thyroid disorders. The levels of FT3, FT4, and SIC exhibited a gradual decline and the concentration of TSH exhibited a gradual increase trend throughout the progression of pregnancy in euthyroid pregnant women. There were no significant differences in neonatal outcomes and neonatal TSH values among euthyroid pregnant women and thyroid disorders pregnant women. SIC had a significant impact on maternal FT4 levels throughout all three trimesters, with varying degrees of importance observed in each trimester. TSH level emerged as the primary determinant of FT4 during the first trimester, while SIC exerted a predominant influence on FT4 levels in the second and third trimesters. The prevalence of thyroid disorders in pregnant women was the lowest when the SIC of pregnant women was probable in the range of 60~70 μg/L, 24-hours UIE was in the range of 250~450 μg, and Tg was in the range of 9~21 μg/L. Maternal TSH exhibited a notable influence on neonatal TSH levels, particularly at the 50th and 75th quantiles. Among the iodine nutritional indicators, SIC and morning UIC demonstrated higher AUC values for abnormal FT4 and TSH, respectively., Discussion: The iodine nutrition status of pregnant women exerts an impact on their thyroid function and prevalence of thyroid disorders, and neonatal TSH was affected by maternal TSH. SIC may be a better indicator for iodine nutritional assessment than other indexes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Fan, Bu, Chen, Wang, Zhang, He and Sun.)

Objective To investigate the relationship between the urinary iodine levels and thyroid diseases in adults in Kunming. Methods A total of 266 residents aged 18 years or older who came to see a doctor or had the physical examination and agreed and signed the informed consent were investigated in the Endocrinology Department of Ganmei Hospital affiliated to the First People's Hospital of Kunming from January 1, 2018 to December 30, 2018. All subjects were divided into group without thyroid disease, thyroid nodular group, Hashimoto's disease group, and Hashimoto's combined nodule group. All subjects were tested for TT3, TT4, FT3, FT4, TSH, TPOAb, TgAb, urine iodine, and thyroid ultrasound Etc to analyze the relationship between thyroid disease and urinary iodine. Results (1) There were statistical differences in age and urinary iodine groups among multiple groups (P < 0.05). Pairwise comparison: Compared with normal ones, There were statistically significant differences in age and urine iodine in nodule group, Hashimoto's thyroiditis group and Hashimoto thyroid nodule group (P < 0.05); (2) Iodine deficiency accounted for 23.68%, moderate iodine accounted for 66.54%, and iodine excess accounted for 9.78%. The detection rate of each thyroid disease was different in different urine iodine levels (χ² = 15.125, P = 0.019); There was a statistically significant difference in the detection rate of thyroid disease (P < 0.05); (3) The detection rate of thyroid diseases was different in different age groups (χ2 = 26.650, P = 0.000). There was a statistically significant difference in the detection rate of thyroid diseases among people aged < 45 years and 59 years old (P = 0.000). The detection rate of thyroid nodules and Hashimoto's combined nodules increased with age. Conclusion There is a U-shaped relationship between the urinary iodine level and thyroid nodules, Hashimoto's thyroiditis and Hashimoto's combined nodules and with the increase of age, the detection rate of thyroid nodules gradually increases. [ABSTRACT FROM AUTHOR]

Background: Iodine deficiency (ID) is a global problem in individuals living in an iodine-deficient environment, specifically in mountainous regions. However, data regarding the iodine nutritional status of Tibetan people in the plateau are limited. Methods: A population-based survey was conducted from July 2016 to July 2017 in Lhasa, Tibet, including 12 communities in Lhasa city and 10 surrounding rural areas. The iodine nutritional status of Tibetan people was evaluated using the traditional iodine nutrition indexes: urinary iodine concentration (UIC), thyroid size, serum thyroxine, thyrotropin, thyroglobulin antibody and thyroid peroxidase antibody (TPOAb). Results: A total of 2295 healthy participants were screened, and 2160 participants who had completed all the required examinations were enrolled in this study (response rate, 94.1%). Urinary iodine showed a skewed distribution, with a median (upper and lower quartiles) of 154 (99–229) μg/L. The percentages of low iodine (UIC <100 μg/L), adequate iodine (UIC, 100–199 μg/L), and high iodine (UIC ≥200 μg/L) were 25.6%, 42.0%, and 32.4%, respectively. The urinary iodine level in the urban region was higher than that in the rural region (p < 0.05). Urinary iodine levels were lower with increasing age (p < 0.05). The prevalence of hyperthyroidism, hypothyroidism, goiter, TPOAb positivity, and thyroglobulin antibody positivity was 1.0%, 21.8%, 4.7%, 6.6%, and 10.4%, respectively. Logistic regression analysis found that urinary iodine was an independent risk factor for TPOAb positivity (odds ratio = 0.997 [95% confidence interval, 0.995–0.999]; p < 0.001). Conclusions: Compared with individuals living in the plains of China, Tibetan adults have a higher rate of ID. UIC was an independent risk factor for TPOAb positivity. This public health issue should be further investigated. [ABSTRACT FROM AUTHOR]

Pregnant women are more vulnerable to iodine deficiency and iodine excess. The study aimed to assess the changes in iodine nutrition and thyroid function of pregnant women exposed to different iodine sources resulting in various iodine intakes during pregnancy. From 2016 to 2017, 2004 healthy pregnant women aged 20–35 years from Shandong and Tianjin, China, were enrolled. Urinary iodine concentration (UIC), drinking water iodine content (WIC), thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroid hormone (FT4), thyroglobulin (Tg), serum thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) were measured. Pregnant women in both Shandong and Tianjin were iodine sufficient, but the median UIC in pregnant women was significantly higher in Shandong (244 μg/L) than that in Tianjin (159 μg/L). No differences were found in UIC over the course of gestation in Shandong. In Tianjin, the UIC decreased during 13–24 weeks and stabilized thereafter. Compared with Tianjin, TSH levels were higher and FT3 and FT4 levels were lower in Shandong. Both FT3 and FT4 significantly decreased during pregnancy in Shandong and Tianjin. TSH and Tg increased over the course of gestation in both Shandong and Tianjin. The iodine status of pregnant women in Tianjin and Shandong were sufficient, but different changing patterns in UIC and thyroid function during pregnancy were presented. More attention should be focused on iodine nutrition of pregnant women, even in iodine-sufficient areas. [ABSTRACT FROM AUTHOR]

In recent decades, the prevalence of thyroid nodules (TNs) has steadily increased in pregnant women. Therefore, this study aimed to investigate associations between TNs and iodine intake in pregnant women. From March 2016 to May 2017, serum and spot urine samples, as well as demographic data and medical history, were collected from 2353 pregnant women. Urine iodine concentration (UIC) and creatinine (Cr) level were determined in spot urine samples; serum thyroid hormones and thyroid autoantibodies were also determined. We examined the hypothesis that excess iodine intake influences incidence of TNs. Herein, TNs were diagnosed by ultrasonography, whereas demographic data and medical history were collected by questionnaire. Multivariate logistic regression models were used to calculate the odds ratios and their corresponding confidence intervals for TN risk factors. Generalized linear mixed model was used to assess the random effects of the regions. The UIC and UIC to creatinine ratio (I/Cr ratio) were significantly higher in pregnant women with TNs (168 and 190 μ g/L, respectively, for UIC [ P <.01]; 139 and 155 μ g/g, respectively, for I/Cr ratio [ P <.01]). Thyroglobulin, age, pre-pregnancy body mass index, and iodine-excessive region were associated with TNs (odds ratio = 1.01, 1.06, 1.04, and 2.38, respectively). Whereas I/Cr ratio was not a significant risk factor for TNs in pregnant women when adjusted for potential confounders, iodine excess (I/Cr ratio >500 μ g/g) was a risk factor in pregnant women in their second trimester. People living in areas with excessive iodine in drinking water should decrease their iodine intake, and a safe water source should be provided to ensure that the I/Cr ratio of pregnant women can be maintained at an optimal level. [ABSTRACT FROM AUTHOR]

Dietary iodine is important to human health, and both low and high iodine intake levels increase the risk of disease. Seaweed is rich in iodine and it is a common component in both Asian and in Arctic cuisines. While the intake and impact are known for Asian people, data are lacking for Arctic people. We aimed to (1) measure iodine content of dietary seaweeds in Greenland, (2) estimate iodine absorption, and (3) assess the impact on iodine intake in Arctic people. A hunter in East Greenland donated household seaweed for (1) measurement of iodine content and (2) ingestion of 45 g by each of eight individuals with subsequent urine collections. (3) In Ammassalik, 96% of 50–69-year-old Inuit reported on the frequency of intake of seaweed and provided a spot urine sample for iodine measurement. Seaweed species provided were Chondrus crispus and Ascophyllum nodosum. (1) The iodine content was 47 and 102 mg/g, respectively. (2) An estimated 1.1 and 1.9 mg of the ingested 2.1 and 4.6 of iodine in seaweed were excreted in the urine within 2 days. (3) More than two in three Inuit reported some dietary use, and 41% (109 of 268) reported a weekly intake of dietary seaweed, which was associated with iodine excretion. In conclusion, the iodine content of edible seaweeds in the Arctic is very high and bioavailable. Dietary intake contributed to the recommended iodine intake level, but marked variation in iodine excretion calls for evaluation of the impact on thyroid function. [ABSTRACT FROM AUTHOR]

Excess iodine intake by the pregnant dam reduces lamb serum antibody concentration, specifically immunoglobulin G (IgG). An experiment was conducted to investigate the mechanisms under pinning the reduced serum IgG concentration at 24 h postpartum in the progeny of iodine supplemented dams. Forty-five mature twin bearing ewes (n=15/treatment) were allocated to one of three dietary treatments as follows: basal diet (Control); basal diet plus 26.6 mg of iodine per ewe per day as calcium iodate (CaIO3); or potassium iodide (KI). Ewes were individually housed and fed from d 119 of gestation until parturition. All lambs received colostrum at 1, 10 and 18 h postpartum via stomach tube. At 1 h postpartum lambs from the control and an iodine supplemented treatment (n=10 per treatment from control and CaIO3) were euthanised before colostrum consumption and ileal segments isolated to determine the gene expression profile of a panel of genes identified as having a role in antibody transfer. Preceding euthanasia, lambs were blood sampled for determination of serum IgG, total thyroxine and free tri-iodothyronine concentrations. Progeny of CaIO3 supplemented dams had lower tri-iodothyronine concentrations (P

Background: In 1993, Nigeria enacted a law making it mandatory for all salt both for human and animal consumption to be fortified with iodine in a bid to eliminate iodine deficiency disorders (IDDs). IDD is a silent threat to the growth and development of the child and also to national development. The aim of this study was to assess the status of iodine nutrition in schoolchildren in areas known for the production of local uniodized salt. Materials and Methods: A cross-sectional study was performed in two Local Government Areas of Ebonyi State, Nigeria. Urinary iodine concentration (UIC) was measured in 400 pupils aged 6–12 years old. In addition, the iodine content of kitchen salt samples of the pupils that donated their urine samples were estimated qualitatively using rapid test kit. Salt samples from markets within the localities were also tested to ascertain the level of iodine. Results: Median UIC of the schoolchildren was 145 μg/L and 31.19% of the schoolchildren had sufficient/adequate iodine intake (100–199 μg/L). Household salt iodization testing showed that 90.0% of the total household salt samples collected during the survey proved iodized; however, only 63.5% were adequately iodized (≥15 parts per million [ppm]). Market salt samples tested showed that three brands of salt were adequately iodized (≥15 ppm), whereas two brands of salt were not iodized (0 ppm). Conclusion: Even though the median UIC in the total study population was at the recommended level (100–199 μg/L), indicating optimal iodine nutrition, the proportion of households consuming adequately iodized salt (63.5%) was below the recommended target of >90%.

Background: Iodine deficiency is a major public health problem in pregnant women. Serum iodine (SI) may represent a useful biomarker for iodine nutrition evaluation. We aimed to assess the relationship between serum iodine concentration (SIC) and urinary iodine concentration (UIC), dietary iodine, thyroid function, and thyroid diseases in pregnant women in the southeast coast of China, and to provide a normal reference range of SIC for pregnant women., Methods: A multistage random sampling method was used to select the study population. We collected urine and blood samples from pregnant women and determined UIC and SIC as well as thyroid function using Arsenic-Cerium Catalytic Spectrophotometry, inductively coupled plasma mass spectrometry, and Beckman Coulter Access2 chemiluminescent immunoanalyzer and kit, respectively, and administered a questionnaire on dietary iodine intake in pregnant women., Results: There was a significant negative correlation between SI and thyroid-stimulating hormone (TSH) ( r = -0.141) and a significant positive correlation between SI and free triiodothyronine (FT 3 ) ( r = 0.106), free thyroxine (FT 4 ) ( r = 0.236), triiodothyronine (TT 3 ) ( r = 0.229), total thyroxine (TT 4 ) ( r = 0.433), and dietary iodine intake ( r = 0.068). There was a significant difference in SI levels of pregnancy between the second (78.13 μg/L) and third trimester (75.37 μg/L) ( p = 0.018). SI levels between inadequate intake (74.58 μg/L) and appropriate intake (77.92 μg/L) groups were statistically different ( p = 0.036). Low SIC was a risk factor for the development of hypothyroxinemia (adjusted OR = 3.14, 95% confidence interval: 1.75-5.66). The reference range for SIC in normal pregnant women is 45.03-112.44 μg/L., Conclusion: SI may be a composite indicator of iodine nutritional status and thyroid function., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ji, Wu, Wu, Chen and Chen.)

Objective: We sought to assess the universal salt iodization (USI) strategy in Armenia by characterizing dietary iodine intake from naturally occurring iodine, salt-derived iodine in processed foods and salt-derived iodine in household-prepared foods.Design: Using a cross-sectional cluster survey model, we collected urine samples which were analysed for iodine and sodium concentrations (UIC and UNaC) and household salt samples which were analysed for iodine concentration (SI). SI and UNaC data were used as explanatory variables in multiple linear regression analyses with UIC as dependent variable, and the regression parameters were used to estimate the iodine intake sources attributable to native iodine and iodine from salt in processed foods and household salt.Setting: Armenia is naturally iodine deficient; in 2004, the government mandated a USI strategy.Subjects: We recruited school-age children (SAC), pregnant women (PW) and non-pregnant women of reproductive age (WRA).Results: From thirteen sites covering all provinces, sufficient urine and table salt samples were obtained from 312 SAC, 311 PW and 332 WRA. Findings revealed significant differences between groups: contribution of native iodine ranged from 81% in PW to 46% in SAC, while household salt-derived iodine contributed from 19% in SAC to 1% in PW.Conclusions: Differences between groups may reflect differences in diet. In all groups, household and processed food salt constituted a significant part of total iodine intake, highlighting the success and importance of USI in ensuring iodine sufficiency. There appears to be leeway to reduce salt intake without adversely affecting the iodine status of the population in Armenia. [ABSTRACT FROM AUTHOR]

The nutritional iodine deficiency disorders are still a major health problem in industrialized countries, but they are completely preventable by means of iodine prophylaxis. Iodine is essential for thyroid hormone (TH) synthesis and TH is required for normal brain development. Gestational iodine supplementation may improve infant cognitive development. In this study we aimed at evaluating the intelligence quotient of children born to mothers with different levels of iodine supplementation, with or without the administration of levothyroxine (LT4), prior to and during pregnancy. In particular we focused our attention on some mother-child pairs and we compared them according to iodized salt consumption and LT4 treatment. In this specific context, NPC test was applied to compare four groups of children, defined on the basis of maternal history related to iodized salt consumption and LT4 treatment. The results show that the deficit in functionality cognitive (in terms of intelligence quotient) is significantly higher in the children of mothers that does not make supplementation of iodized salt. This shows how a lack of iodine can hinder children in reaching their full intellectual potential. From a methodological point of view, our research showed the utility of the Non Parametric Combination test (NPC test) into analyze data concerning medical research. [ABSTRACT FROM AUTHOR]

Many studies focused on the association between thyroid disease and pregnancy outcomes. The present study explored the effect of iodine nutrition during the first trimester on pregnancy outcomes. One thousand five hundred sixty-nine pregnant, euthyroid women at ≤12 weeks of gestation in an iodine-sufficient area in China were recruited. According to the World Health Organization (WHO) criteria for iodine nutrition during pregnancy, participants were divided into four groups: adequate iodine (median urinary iodine concentration (UIC), 150-249 μg/L), mild deficiency (UIC, 100-150 μg/L), moderate and severe deficiency (UIC, <100 μg/L), and more than adequate and excessive (UIC, ≥250 μg/L) groups. Pregnancy outcomes, including abortion, gestational hypertension, pre-eclampsia, gestational diabetes mellitus (GDM), placenta previa, placental abruption, preterm labor, low birth weight infants, macrosomia, breech presentation, and cord entanglement, were obtained during follow-up. The results showed that there was no significant difference in general characteristics, including age, body mass index, abdominal circumference, systolic blood pressure, diastolic blood pressure, heart rate, smoking rate, and drinking rate, among the four groups. In the more than adequate and excessive group, thyroid-stimulating hormone (TSH) was greater and free thyroxine (FT4) was lower than any other groups but still within normal range. The thyroglobulin (Tg) level was greater in the moderate and severe deficiency group. The incidence of GDM was significantly greater in women with mild iodine deficiency than in women with adequate iodine nutriture (18.38 vs. 13.70%, p < 0.05). Compared with the adequate group, incidence of macrosomia was significantly greater in the more than adequate and excessive group (12.42 vs. 9.79%, p < 0.05). Mild iodine deficiency was an independent risk factor for GDM (odds ratio = 1.566, 95% confidence interval = 1.060-2.313, p = 0.024); more than adequate and excessive iodine was an independent risk factor for macrosomia (OR = 1.917, CI = 1.128-3.256, p = 0.016). In summary, during 1st trimester, both mild iodine deficiency and excessive iodine intake had adverse impacts on pregnancy outcomes in an iodine-sufficient area. [ABSTRACT FROM AUTHOR]

Currently, hypothyroidism is usually treated only with drugs; patients are never told that they could regulate their levels of iodine with dietary recommendations in a complementary way. The objective of this work was to explore the effect of a constant iodine intake through the diet in a postmenopausal woman with subclinical grade II hypothyroidism, who also had mild hypercholesterolemia and obesity. Baseline anthropometric nutritional, pharmacological, and habit data were obtained, then the woman was scheduled for 1 month a diet in which she was provided food naturally containing iodine, so that the recommended requirements (iodine 150 μg/day) were met. All the information about which foods contain this mineral was supplied and explained to the patient. This diet was also designed to help her to gradually lose weight, and was more balanced and closer to the nutritional recommendations. The results obtained in this work were satisfactory, having achieved improved blood levels of thyroid-stimulating hormone (1.78 μIU/mL) and reduced total cholesterol levels (198 mg/dL). Statement of hypercholesterolemia was demoted. In addition, a significant improvement in relation to weight and body volume was reached (body mass index fell from 30.13 to 28.5 kg/m2), an important fact since it has impacted the overall well-being of the patient. In conclusion, it was demonstrated that a constant iodine intake through the diet for this patient with grade II hypothyroidism was very effective, and therefore, this aspect should be also considered during hypothyroidism treatment. [ABSTRACT FROM AUTHOR]

Iodine nutritional status of 128 lactating mothers and their breast-fed infants (1-3 months) from iodine-replete villages during post-salt iodization period was evaluated. Mothers' urine, blood, and breast milk (BM) and infants' urine and blood were collected and analyzed for iodine and serum FT4 and TSH estimation. Mothers' and infants' age, parity, occupation, education, and household income were recorded. Median urinary iodine concentration (UIC) of infants was 250 μg/L, indicating their iodine intake was more than adequate. Mothers' median UIC was 185 μg/L, indicating adequate iodine nutrition; however, 13.28% had mild to severe deficiency. Median breast milk iodine concentration (BMIC) was 230 μg/L, which was more than their median UIC 185 μg/L. In iodine-deficient mothers, positive correlation was found between mothers' and infants' serum FT4 and TSH levels, and negative correlation was found between mothers' and infants' serum FT4 and TSH levels in excessive iodine nutrition group.Conclusion: Iodine intake of breast-fed infants was at the limit of above requirement, and they are possibly at the risk of excess iodine intake. In iodine deficient and excessive iodine intake mothers, their infants' serum FT4 and TSH are independent on their iodine nutritional status but dependent on thyroid hormone profile of their mothers but differently. What is Known: • A median urinary iodine of 100 μg/L is used to define adequate iodine intake of lactating mothers and children < 2 years. However, adequate iodine intake in terms of urinary iodine of infants of age 1-3 months is not known. What is New: • Iodine intake of absolutely breast-fed infants (1-3 months) was more than adequate, though their mother's intake was adequate as breast milk contains more iodine than urine. The infants of iodine deficient and excessive iodine intake mothers, infants' hormonal profile is independent of their iodine nutritional status but dependent on their mothers thyroid hormone profile. [ABSTRACT FROM AUTHOR]

Thyroid volume was proposed as a factor for malignancy in evaluating thyroid nodules. Previous studies have demonstrated the endocrine disrupting effect of polycyclic aromatic hydrocarbons (PAHs), but studies on the association between internal exposure of PAHs and thyroid volume are still scarce. In this work, we evaluated the association of polycyclic aromatic hydrocarbon internal exposure and urinary iodine concentration with thyroid volume in 590 school-age children without thyroid disease in Guangzhou, China. Urinary hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs), urinary iodine concentrations, and thyroid volumes were measured. The mean concentrations of urinary iodine and ΣOH-PAHs were 271.1 μg/L and 3.27 μg/L, respectively, and the mean thyroid volume was 2.4 mL. The associations of urinary iodine and OH-PAH concentrations with thyroid volume were investigated by multivariable linear regression and the Bayesian kernel machine regression models. Urinary ΣOH-PAHs were observed to be significantly positively associated with thyroid volume in multivariable linear regression models. The increase in each unit in the log-transformed concentration of ΣOH-PAHs caused 3.88% change in thyroid volume. The Bayesian kernel machine regression model demonstrated a positive joint effect of increased urinary ΣOH-PAHs on thyroid volume. Moreover, urinary ΣOH-PAHs were statistically significant linked to urinary iodine, and iodine mediated the relationship between urinary OH-PAHs and thyroid volume with the mediated proportions of 15.2% [Display omitted] • Urinary OH-PAHs, iodine, and thyroid volume were monitored in children. • Urinary OH-PAHs were significantly positively associated with thyroid volume. • Iodine may mediate the relationship between urinary OH-PAHs and thyroid volume. [ABSTRACT FROM AUTHOR]