Excess Iodine Research Articles

Characterization of anti-thyroglobulin antibodies epitopes in patients with hashimoto's thyroiditis in areas with normal and excessive iodine intake

Characterization of anti-thyroglobulin antibodies epitopes in patients with hashimoto's thyroiditis in areas with normal and excessive iodine intake

A study of programmed death-1/programmed death ligand and iodine-induced autoimmune thyroiditis in NOD.H-2h4 mice.

Excess iodine will trigger the occurrence of autoimmune thyroiditis (AIT), and programmed death-1 (PD-1)/programmed death ligand (PD-L) will also contribute to the development of AIT. The purpose of this study was to explore the role that negative regulatory signals mediated by PD-1/PD-L play in the development of spontaneous autoimmune thyroiditis (SAT) in NOD.H-2h4 mice when they are exposed to iodine. Programmed death ligand 1 (PD-L1) antibody was administered intraperitoneally to NOD.H-2h4 mice. The relevant indicators were determined by flow cytometry, real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, immunohistochemistry, pathological hematoxylin and eosin staining, and arsenic-cerium catalytic spectrophotometry. Results showed that the level of urinary iodine, the level of thyroid lymphocyte infiltration, the level of thyroglobulin antibodies (TgAb) and interferon (IFN-γ)/tumor necrosis factor (TNF-α)/interleukin (IL-2)/IL-17, and the relative expression of PD-1/PD-L1/programmed death-2 (PD-L2) increased with the intervention of excess iodine. After the intervention of the PD-L1 antibody, the expression of PD-1/PD-L1/PD-L2 in different degrees was inhibited, but the level of thyroid lymphocyte infiltration and serum TgAb/IFN-γ/TNF-α/ IL-2/IL-17 did not decrease. Collectively, although PD-1/PD-L participates in the occurrence of SAT and induces inflammation, administration of the PD-L1 antibody does not effectively improve the pathological process of SAT. More research is needed to determine whether PD-1/PD-L intervention can treat autoimmune thyroid disease.

Age-dependent association of high urinary iodine concentration with major depression in adults: NHANES 2007–2020

Excessive iodine exposure can have detrimental effects on thyroid function and overall health. This study aimed to investigate the age-dependent association between high urinary iodine concentration (UIC) and major depression symptoms in adults, using data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2020. To perform stratified analysis by age, we utilized a rolling window method with a 15-year window width to examine the trend of the odds ratios (ORs) of UIC on depression symptoms with age. Full-factor and one-factor multinomial logistic regression models were employed to calculate the ORs, and violin plots were utilized to depict the ORs of UIC on major depression. The LASSO regression was applied to select variables for one-factor models. The bootstrap method was utilized to ensure the robustness of the results, and the Games-Howell test was applied to compare the differences in the bootstrapped ORs of different UIC groups. Our results indicate that, after age 46, the ORs of high UIC (≥ 300 μg/L) on major depression are significantly higher than those of normal UIC (100–199 μg/L). The bootstrapped ORs of high UIC on major depression calculated by the full-factor and one-factor multinomial logistic regression models are 1.9 (1.28, 2.82) and 1.42 (1.02, 1.93) among participants aged 46 and older, respectively. Based on these findings, we conclude that major depressive symptoms are significantly associated with high UIC among older individuals aged 46 and above.

Biological regulation on iodine using nano-starch for preventing thyroid dysfunction

The growing incidence of thyroid disease triggered by excess iodine uptake poses a severe health threat throughout the world. Extracellular interference therapies impede iodine transport across the sodium-iodide symporter (NIS) membrane protein and thus prevent excessive iodine uptake by thyroid cells, which may lessen the occurrence of disease. Herein, we for the first time utilized nano-starch particles (St NPs) to regulate iodine transport across the NIS protein of thyroid cells by using extracellular interference therapy. By precisely encapsulating iodine within the cavity of a glucan α-helix via hydrogen bonding, extracellular St NPs prevented excess iodine uptake by thyroid cells in vitro and in vivo; this down-regulated the expression of NIS protein (0.06-fold) and autophagy protein LC3B-II (0.35-fold). We also found that St NPs regulated the metabolic pathway of iodine in zebrafish. We believe this proposed strategy offers a novel insight into controlling iodine uptake by the thyroid and indicates a new direction for preventing iodine-induced thyroid disease.

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

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

Association study of urinary iodine concentrations and coronary artery disease among adults in the USA: National Health and Nutrition Examination Survey 2003-2018.

Iodine is a vital trace element in the human body and is associated with several important coronary artery disease (CAD) risk factors. We aimed to explore the correlation between urinary iodine concentration (UIC) and CAD. Data from 15793 US adults in the National Health and Nutrition Examination Survey (2003-2018) were analysed. We conducted multivariable logistic regression models and fitted smoothing curves to study the correlation between UIC and CAD. Furthermore, we performed subgroup analysis to investigate possible effect modifiers between them. We found a J-shaped association between UIC and CAD, with an inflection point at Lg UIC = 2·65 μg/l. This result indicated a neutral association (OR 0·89; 95 % CI 0·68, 1·16) between UIC and CAD as Lg UIC < 2·65 μg/l, but the per natural Lg [UIC] increment was OR 2·29; 95 % CI 1·53, 3·43 as Lg UIC ≥ 2·65 μg/l. An interaction between diabetes and UIC might exist. The increase in UIC results in an increase in CAD prevalence (OR 1·84, 95 % CI 1·32, 2·58) in diabetes but results in little to no difference in non-diabetes (OR 0·98, 95 % CI 0·77, 1·25). The J-shaped correlation between UIC and CAD and the interaction between diabetes and UIC should be confirmed in a prospective study with a series of UIC measurements. If excessive iodine precedes CAD, then this new finding could guide clinical practice and prevent iodine deficiency from being overcorrected.

An update: maternal iodine supplementation, thyroid function tests, and child neurodevelopmental outcomes.

The impact of maternal iodine supplementation (MIS) during pregnancy on thyroid function and child neurodevelopmental outcomes in areas of mild-to-moderate iodine deficiency (MMID) remains unclear. Despite growing success of salt iodization programs, a 2022 meta-analysis found that 53% of pregnant patients worldwide continue to have insufficient iodine intake during pregnancy. A 2021 randomized controlled trial (RCT) found that MIS in women with mild iodine deficiency led to iodine sufficiency and positive effects on maternal thyroglobulin. A 2021 cohort study of MIS initiated prior to pregnancy was associated with lower thyroid-stimulating hormone (TSH), higher FT3, and FT4. Other cohort studies, however, found that neither salt iodization nor MIS were adequate to meet pregnancy iodine needs. Data have been mixed regarding maternal iodine status and pregnancy outcomes in patients of MMID. Meta-analyses have not shown any clear benefit on infant neurocognitive outcomes with MIS of MMID patients. A 2023 meta-analysis found that the prevalence of excess iodine intake in pregnancy was 52%. MMID continues to exist during pregnancy. Salt iodization alone may be insufficient to ensure adequate iodine status during pregnancy. There is an absence of high-quality data to support routine MIS in areas of MMID. However, patients with specialized diets (vegan, nondairy, no seafood, noniodized salt, and so on) may be at risk for inadequate iodine status in pregnancy. Excess iodine intake can be detrimental to the fetus and should be avoided during pregnancy.

Seaweed as food: survey of the UK market and appraisal of opportunities and risks in the context of iodine nutrition

Purpose Seaweeds are gaining broader interest in Western societies through their use in product development and the health-food industry. High nutritional value, low carbon footprint and sustainability are key drivers for seaweed uptake in Europe; yet high iodine intake from seaweed remains a concern. This study seeks to identify seaweed food products available on the UK retail market between 2018 and 2021 and assess their safety in the context of iodine exposure.Design/methodology/approach Here, a market survey (n = 37–40 retailers) was conducted in three annual waves to evaluate seaweed food product availability in the UK. The iodine dose of products was estimated based on a comprehensive literature review of seaweed iodine content.Findings This study shows a young, dynamic market with 2.3-fold increase in seaweed food product availability since the last available published data (2015). Specific iodine content labelling remains uncommon, and median iodine doses in a single serving of food exceeded 400 µg in all years. Some products, especially seaweed supplements, provide iodine doses above the tolerable upper limit and upper level of tolerance.Originality/value This study presents the most contemporary and comprehensive overview of the market for seaweed food products in the UK. With increasing popularisation of seaweed as a food, this study highlights the need for improved dialogue amongst producers, retailers, legislators and public health specialists to address the risk of iodine excess, and the concurrent scope for processing methods to reduce the iodine content in seaweeds.

Iodine status and its association with prevalence of thyroid diseases in adults from Jiangxi Province, China.

Iodine is an essential element for the biosynthesis of thyroid-stimulating hormone (TSH). Both excessive and deficient iodine are major risk factors for thyroid diseases, including thyroid dysfunction, thyroid nodules, and thyroid autoimmunity (TAI). This study aimed to elucidate the relationship between iodine status and the prevalence of thyroid diseases through a national cross-sectional epidemiological survey in Jiangxi province (China). This population-based, cross-sectional study enrolled 2636 Chinese local inhabitants who aged over 18 years old from April to August in 2015. Physical examination was performed and biochemical indices, urinary iodine concentration (UIC), and TSH level were measured. The Chi-square test, nonparametric test, and 4 multivariate logistic regression models adjusted for risk factors were applied to analysis. Spearman correlation coefficients were calculated to investigate the relationship between iodine intake level and the prevalence of thyroid diseases. The median UIC was 176.4 μg/L, and a significant difference was found in median UIC between men (182.45 μg/L) and women (169.25 μg/L) (P = 0.03). Among these study subjects, 14.4%, 44.5%, 26.1%, and 15.0% had deficient, adequate, more than adequate, and excessive iodine concentrations, respectively. The prevalence rates of hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, subclinical hypothyroidism, thyroid nodules, and TAI were 0.91%, 0.57%, 0.34% and 7.89%, 9.45%, and 12.7%, respectively. Significant differences were found in iodine status, waist circumstance, systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), TSH, thyroid nodules, and TAI between men and women (P < 0.05). Compared with those with adequate UIC, subjects with excessive UIC had higher prevalence rates of thyroid dysfunction (odds ratio (OR) = 1.74, 95% confidence interval (CI): 1.40-2.54) and thyroid nodules (OR = 3.33, 95%CI 1.32-8.42). In addition, subjects with deficient and excessive UIC were at the higher risk of TAI compared with those with adequate UIC (OR = 1.68, 95%CI: 1.19-2.60; OR = 1.52, 95%CI: 1.04-2.96, respectively). UIC was positively correlated with the prevalence rates of thyroid nodules (r = -0.44, P < 0.01) and TAI (r = -0.055, P < 0.01). On the contrary, UIC was negatively correlated with the risk of thyroid dysfunction (r = -0.24, P > 0.05). Adult inhabitants from Jiangxi province in the TIDE study were in the adequate iodine status. Excessive iodine status was noted as a risk factor for thyroid dysfunction and thyroid nodules. In addition, both iodine deficiency and excessive iodine were risk factors for TAI.

The Role of Thyroid Hormone Synthesis Gene-Related miRNAs Profiling in Structural and Functional Changes of The Thyroid Gland Induced by Excess Iodine.

At recent years, the impairment caused by iodine excess are paid more attention. However, there is still largely unknown about the exact mechanism induced by excessive iodine. MiRNAs have been found to act as biomarkers for a variety of diseases, whereas fewer studies focused on miRNAs related to a cluster of genes regulating thyroid hormone synthesis, such as NIS, Pendrin, TPO, MCT8, TSHR, TSHα, and TSHβ-related miRNAs in structural and functional changes of the thyroid gland induced by subchronic and chronic high iodine exposure. In the present study, one hundred and twenty 4-week-old female Wistar rats were randomly divided into control group (I50µg/L KIO3); HI 1 (I6000µg/L KIO3); HI 2 (I10000µg/L KIO3); and HI 3 (I50000µg/L KIO3), the exposure period was 3months and 6months, respectively. The iodine contents in the urine and blood, thyroid function, and pathological changes were determined. In addition, levels of thyroid hormone synthesis genes and the associated miRNAs profiling were detected. The results showed that subclinical hypothyroidism occurred in the high iodine groups with subchronic high iodine exposure, while 6-month exposure led to hypothyroidism in the I10000µg/L and I50000µg/L groups. Subchronic and chronic high iodine exposure caused mRNA and protein levels of NIS, TPO, and TSHR decreased significantly, and Pendrin expression increased significantly. In addition, MCT8 mRNA and protein levels are only remarkably decreased under the subchronic exposure. PCR results showed that levels of miR-200b-3p, miR-185-5p, miR-24-3p, miR-200a-3p, and miR-25-3p increased significantly exposed to high iodine for 3months, while miR-675-5p, miR-883-5p, and miR-300-3p levels increased significantly under the exposure to high iodine for 6months. In addition, miR-1839-3p level was markedly decreased exposed to high iodine for 3 and 6months. Taken together, the miRNA profiling of genes regulating thyroid hormone synthesis remarkably altered from subclinical hypothyroidism to hypothyroidism induced by excess iodine exposure, and some miRNAs may play an important role in subclinical hypothyroidism or hypothyroidism through regulating NIS, Pendrin, TPO, MCT8, and TSHR providing promising targets to alleviate the impairment on the structure and function of thyroid gland.

I-Rich Thioantimonate Argyrodite Glass-Ceramic Electrolyte with High Air Stability and Compatibility with Lithium

The argyrodite solid electrolyte has been actively studied due to its high ionic conductivity and good physical properties. However, it has various problems due to low air stability characteristics and low critical current density. In this study, the air stability and electrochemical performance of the solid electrolyte were improved by introducing a method to improve the performance of the solid electrolyte by adding excess iodine based on a thioantimonate-based argyrodite solid electrolyte with excellent air stability. I-rich glass-ceramic argyrodite Li6–xSbS5–xIx was prepared through high-energy ball milling. The structural properties were confirmed using powder X-ray diffraction (XRD). The synthesized Li5.6SbS4.6I1.4 electrolyte showed a higher ionic conductivity of 0.66 mS/cm and a lower activation energy of 0.32 eV compared to pristine Li6SbS5I (0.17 mS/cm, 0.33 eV) at 25 °C. In addition, the high lithium compatibility of the Li5.6SbS4.6I1.4 solid electrolyte was confirmed through DC cycling and cyclic voltammetry, and it showed a high ion conductivity retention rate of 61% after exposure to the atmosphere for 30 min. Finally, the optimized cell with Li6PS5Cl–Li5.6SbS4.6I1.4 solid electrolyte showed a higher initial discharge capacity of 154 mAh/g and Coulombic efficiency of 70%. In particular, it was confirmed that the performance at a high C rate was greatly improved compared to the cell made with Li6PS5Cl.

The Relationship Between Iodine Excess and Thyroid Function During Pregnancy and Infantile Neurodevelopment at 18–24 Months

BackgroundThyroid disease is a prevalent condition during pregnancy, and excessive iodine intake can lead to changes in thyroid function. However, research on the relationship between maternal iodine excess, thyroid hormones during pregnancy, and infantile neurodevelopment is limited. ObjectivesThis study aimed to explore the relationship between maternal iodine excess and thyroid hormones during pregnancy and infantile neurodevelopment. The objective was to provide evidence to support and enhance the prevention of neurodevelopmental retardation in infants. MethodsFrom 2016 to 2018, a prospective study was conducted from pregnancy to 18–24 mo postpartum. Maternal urinary iodine concentration (UIC), thyroid-stimulating hormone (TSH), total serum iodine (TSI), and nonprotein-bound serum iodine during pregnancy were determined. The Gesell Development Scale was used to assess neurodevelopment of infants aged 18–24 mo. The iodine status of pregnant females was divided into following 4 groups on the basis of the distribution of maternal UIC: <100 μg/L (moderate deficiency), 100–149 μg/L (mild deficiency), 150–249 μg/L (sufficiency), and >250 μg/L (above requirement). ResultsOur study included 469 mother-infant pairs. Compared with the maternal UIC of 150–249 μg/L during pregnancy, risk of adaptive developmental delay was increased in infants with maternal UIC ≥250 μg/L (OR: 2.38; 95% CI: 1.06, 5.35). Pregnant females with TSI >90th quantiles were more likely to have offspring with language developmental delay than those with lower TSI in 10th–90th quantiles (OR: 3.06; 95% CI: 1.09, 8.58). Risk of fine motor developmental delay was increased in infants with maternal TSH ≥2.5 mIU/L during pregnancy (OR: 4.32; 95% CI: 1.43, 13.0). ConclusionsMaternal iodine nutritional status above requirement (UIC ≥250 μg/L or TSI >90th quantiles) during pregnancy negatively affects infantile neurodevelopment. Maternal TSH ≥2.5 mIU/L during pregnancy was an independent risk factor for infantile neurodevelopment. This trial was registered at clinicaltrials.gov as NCT03710148.

Methyl orange as a novel colorimetric iodide indicator with in situ generation of H2O2 by etching uncoated Ag–Ti3C2 nanohybrids

Iodine intake remains a major public health concern, as both iodine excess and deficiency are related to adverse effects on health. Therefore, developing simple and economical methods to detect I− is still in great demand. Herein, we constructed a visual I− sensing platform based on the uncoated Ag–Ti3C2 nanohybrids using methyl orange (MO) as a colorimetric indicator. Plasmonic nanostructures are frequently employed in colorimetric analysis, but uncoated Ag nanoparticles (NPs) are unstable because their surface energies are usually high. Considering that Ag NPs can be etched by I− via forming Ag–I bond, we introduce Ag–Ti3C2 nanohybrids because uncoated Ag NPs with immaculate surfaces are more conducive to binding with I− and being etched. Dissolved O2 molecules adsorbed on Ti3+ of Ti3C2 MXenes enable the in situ generation of H2O2 by iodine-etching of uncoated Ag–Ti3C2 nanohybrids. ∙OH radicals promote the degradation of MO through a self-driven Fenton-like process, exhibiting the color variation from orange to transparent. Under optimal conditions, the absorbance of MO at 465 nm decreases linearly with the concentration of I− in the range of 0.5–300 μM, with a limit of detection as low as 0.31 μM. This work opens the feasibility of iodine-etching of Ag in developing novel probes for facile colorimetric determination of I−.

Factors associated with inadequate urinary iodine concentration among pregnant women in Mbeya region Tanzania.

Background: Insufficient and excessive iodine intake during pregnancy can lead to serious health problems. In Tanzania, information available on iodine status during pregnancy is minimal. The aim of this study was to assess the iodine status and its association with socio-demographic factors in pregnant women in the Mbeya region, Tanzania. Method: A cross sectional survey involving 420 pregnant women (n=420) registered in Reproductive and Child Health Clinics was conducted. Data were collected via interviews and laboratory analysis of urinary iodine concentration (UIC). Results: Median UIC was 279.4μg/L (+/-26.1) to 1915μg/L. Insufficient iodine intake (UIC below 150μg/L) was observed in 17.14% of participants, sufficient intake in 24.29% and 58.57% had intakes above the recommended level (&gt;250μg/L). Pregnant women who consume fish had an increased risk of insufficient iodine [Adjusted OR7= 2.60 (95%CI 1.31-5.15)] while the risk was lower for those who attended primary education compared to non-formal education [Adjusted OR= 0.29 (95%CI 0.08-0.99)]. Pregnant women resident in Mbarali district aged between 35-49 years were associated with an increased risk of UIC above recommended level [Adjusted OR=4.09 (95%CI 1.85-9.010] and [Adjusted OR=2.51 (95%CI 0.99-6.330] respectively . Conclusion: This study demonstrated a significant relationship between geographical factors (residence in the Mbarali district) and excess median urine iodine concentration, in addition, this study also found an association between consumption of freshwater fish and insufficient mean urine iodine concentration as indicated by the World Health Organization recommendation. Therefore, educational programs on iodine intake are needed as attending primary education was found to be a protective factor for insufficient median urine iodine concentration.

Influencing Factors and New Reference Intervals of Adult Thyroid Volume in Iodine-Sufficient Areas of China.

The diagnosis of goiter is based on the thyroid volume measured by ultrasound in which iodine plays an important role. The purpose of this study was to evaluate the factors that affect thyroid volume and update the reference range of thyroid volume to provide a new basis for the diagnosis and treatment of goiter. A study population from mainland China was evaluated in the Thyroid disorders, Iodine status and Diabetes Epidemiological (TIDE) study. Thyroid size was measured by ultrasound, and thyroid volume was calculated. A quantile regression model was used to analyze the influence of related factors on the thyroid volume at each percentile. The median urinary iodine concentration (UIC) was 185.54μg/l. The quantile regression model suggested that body surface area (BSA) and thyroid-stimulating hormone (TSH) were positive and negative factors for thyroid volume, respectively (p < 0.01). Excess iodine reduces the median and lower limits of thyroid volume. In iodine-sufficient areas, smoking is no longer a risk factor. The reference value range of thyroid volume stratified by sex was 3.92-19.06ml for males and 3.1-16.17ml for females. The maximum reference ranges for stratification by sex and BSA were 4.25-20.98ml for men and 3.44-18.31ml for women. The iodine nutrition level of the population in mainland China is sufficient. Iodine has the potential to alter the effect of certain factors on thyroid volume and effect is not regional. The new reference interval of adult thyroid volume based on sex and BSA has been updated, which can be used as a reliable reference for updating the diagnostic criteria of endemic goiter.

Prevalence of Functional Alterations and the Effects of Thyroid Autoimmunity on the Levels of TSH in an Urban Population of Colombia: A Population-Based Study.

The population prevalence of functional alterations and thyroid autoimmunity is high, and numerous genetic and environmental aspects have been described as triggering factors. The objective of this study was to determine the prevalence of functional alterations and thyroid autoimmunity in an urban population of Colombia. It is a cross-sectional, population-based study (n = 9,638) conducted on an urban population of Popayán-Cauca-Colombia between February 5th, 2018, to December 11th, 2021. The variables evaluated were thyrotropin (TSH), free T4 (FT4), and anti-thyroid antibodies (thyroid peroxidase antibodies: TPOAb, and thyroglobulin antibodies: TgAb). TSH in men was significantly higher than in women. No differences were observed in the values of FT4, TPOAb, and TgAb (according to sex). The prevalence of normal thyroid function and subclinical hypothyroidism was significantly higher in men. The positivity of TPOAb and TgAb was 22.3% and 19.2%, respectively. TSH levels increased with age (both in men and in women). In participants with normal FT4 and negative TPOAb, the TSH was significantly higher. TSH was significantly higher in TPOAb-positive individuals and among those with TPOAb and TgAb positives, as well as in women with positive TPOAb and men with positive TPOAb and TgAb. In an urban population of Colombia, TSH was found to be higher than in populations of other geographical areas, especially in older individuals and in the presence of positive anti-thyroid antibodies, a high prevalence of functional alterations and thyroid autoimmunity was also found. These findings can be explained by excess iodine consumption and some environmental factors.

A Cohort Study on the Effects of Maternal High Serum Iodine Status During Pregnancy on Infants in Terms of Iodine Status and Intellectual, Motor, and Physical Development.

The objective of the present study was to explore the effects of maternal iodine excess during pregnancy on infants' neurodevelopment and physical development. A total of 143 mother-child pairs were enrolled in this cohort study. Maternal blood samples were collected during the obstetric examination. A mother-child questionnaire survey was conducted, and infants' blood samples were collected during the newborn physical examination. Infants' single-spot urine samples were collected, and intellectual, motor, and physical development were assessed at 2months of age. The median (IQR) maternal serum iodine concentrations (SICs) in the first, second, and third trimesters of pregnancy were 91.2 (74.4, 102.2) μg/L, 81.2 (70.6, 94.8) μg/L, and 82.0 (68.9, 100.3) μg/L, respectively. In the first trimester of pregnancy, infants' psychomotor developmental index (PDI), body mass index (BMI) and weight-for-length Z score (WLZ) were higher with maternal suitable SIC (40 ~ 92μg/L) than with maternal excess SIC (P < 0.05). Infants' PDI, BMI, weight-for-age Z score (WAZ) and WLZ were negatively correlated with maternal SIC (P < 0.05). Maternal excess SIC had a slightly negative effect on infants' MDI (OR = 1.304, P = 0.035, 95% CI = 1.019 ~ 1.668), PDI (OR = 1.124, P = 0.001, 95% CI = 1.052 ~ 1.200) and BMI (OR = 0.790, P = 0.005, 95% CI = 0.669 ~ 0.933). In the third trimester, infants' length-for-age Z score (LAZ) was higher with maternal high SIC (> 92μg/L) (P = 0.015), and maternal SIC was positively correlated with infants' urine iodine concentration (UIC) (P = 0.026). Maternal iodine excess in the first trimester had a slightly negative effect on infants' intellectual, motor, and physical development. In the third trimester, maternal iodine excess only may have a positive impact on infants' height. Additionally, maternal iodine status was closely related to infants' iodine status.

Changing Iodine Status and the Incidence of Thyroid Disease in Mainland China: A Prospective 20-Year Follow-Up Study.

Background: We aimed to assess the long-term effects of the transition in iodine status on the incidence of thyroid disorders over 20 years of follow-up. Methods: The original prospective cohort study, started in 1999 (n = 3761), classified three regions in north China based on iodine status (insufficient iodine, more than adequate iodine, and excessive iodine, respectively) for 5 years. Subsequently, participants were followed for up to another 15 years to assess the long-term effects of shifts to adequate iodine on the incidence of thyroid disorders. Panshan transitioned from insufficient to adequate iodine, and Huanghua transitioned from excessive to more than adequate iodine. Both regions were compared with Zhangwu, in which iodine status changed from more than adequate to adequate iodine (from 214 to 167.2 μg/L). A cluster sampling method was used to select participants in the three regions. Participants completed questionnaires and underwent thyroid ultrasonography. Urinary iodine concentrations (UICs), serum thyroid hormone concentration, and thyroid antibodies were measured. Results: When the iodine status changed from insufficient to adequate (with the median UIC increasing from 88 to 141.9 μg/L), the incidence density of subclinical hyperthyroidism, positive thyroperoxidase antibody, positive thyroglobulin antibody (TgAb), and goiter decreased significantly (p < 0.05 for all). Additionally, the cumulative incidence of subclinical hypothyroidism was significantly lower compared with the region where the iodine status changed from being more than adequate to adequate (1.9% vs. 6.0%, p < 0.001). When the iodine status changed from excessive to more than adequate (median UIC from 634 to 266.7 μg/L), a significant decrease in the incidence density of subclinical hyperthyroidism, positive thyroid antibodies, positive TgAb, and goiter (p < 0.05 for all) were also found. However, an increase in thyroid nodule incidence density (17.26 vs. 28.25 per 1000 person-years, p < 0.001) was seen. Conclusions: The incidence of thyroid disorders (except for thyroid nodules) stabilized or decreased among adults in the three communities from year 5 to year 15 of follow-up. Appropriate iodine fortification is safe and effective over the long term. Restoring urinary iodine to appropriate levels reduces population risk for thyroid disorders.

A Rare Case of Congenital Hypothyroidism

Congenital Hypothyroidism (CH) is a common preventable cause of mental retardation. The incidence of CH is 1 in 2500 to 1 in 3000 newborns. Most common causes are thyroid dysgenesis and dyshormonogenesis. Some disorder like maternal autoantibodies, maternal intake of anti thyroid medication, iodine deficiency or iodine excess can result in transient CH. Common symptoms include decreased activity and increased sleep, feeding difficulty, constipation, and prolonged jaundice. In this case report, A 3 day old baby was admitted to SNCU with chief complain of yellowish discoloration upto abdomen and respiratory distress. On examination, common signs include myxedematous facies, large fontanels, macroglossia, a distended abdomen with umbilical hernia, and hypotonia. Thyroid dysgenesis accounts for 85% of permanent, primary CH, while inborn errors of thyroid hormone biosynthesis (dyshormonogeneses) account for 10-15% of cases. Secondary or central CH may occur with isolated TSH deficiency, but more commonly it is associated with congenital hypopitiutarism. Transient CH most commonly occurs in preterm infants born.

Serum thyroglobulin as a biomarker of iodine excess and thyroid disease occurrence in adults

BackgroundThyroglobulin (Tg) is considered a sensitive indicator of iodine deficiency. However, the usefulness of Tg as a biomarker of excess iodine is uncertain. The present study aimed to determine the influence of different iodine intake on serum Tg levels, evaluate the influence of thyroid diseases on the distribution of Tg, and identify the factors that may affect Tg levels. MethodsA cross-sectional survey with a total of 1208 adults was conducted in different water iodine areas in China. Urinary iodine concentration (UIC), water iodine concentration (WIC), serum Tg, thyroid-stimulating hormone (TSH), and thyroid antibodies were measured. The thyroid volumes and nodules were measured by B-scan ultrasound. ResultsBased on the WIC data, subjects were divided into three groups. Based on the median urinary iodine concentration (MUIC) data, the iodine levels were adequate, more than adequate, and excess for the WIC < 10 μg/L group, 10 μg/L ≤ WIC ≤ 100 μg/L g, and WIC > 100 μg/L groups, respectively. The median Tg was significantly higher in the excess iodine group than in the adequate iodine group and the more than adequate iodine group (14.6 μg/L vs.12.7 μg/L, P = 0.042; 14.6 μg/L vs.12.5 μg/L, P = 0.004). Multiple linear regression analysis showed that excess iodine intake, goitre, thyroid nodules, and hypothyroidism were significantly related to higher serum Tg levels. ConclusionSerum Tg level can be a promising biomarker of excessive iodine intake, but other factors, especially the presence of thyroid disease, should be considered when using this parameter.