Excessive Iodine Intake Research Articles

Comparison of Salt Iodization Requirements in National Standards with Global Guidelines

ABSTRACTBackgroundFood fortification is the addition of 1 or more micronutrients to commonly consumed foods and is utilized by many countries as a public health intervention to prevent and control micronutrient deficiencies. As iodine deficiency was a major public health issue globally, the WHO developed evidence-based guidelines for the fortification of salt with iodine. The implementation of salt iodization has been highly successful in reducing iodine deficiency disorders worldwide and is recommended as the main strategy to prevent iodine deficiency.ObjectivesThis analysis compared salt iodization requirements specified in countries’ salt standards with WHO 2014 Guidelines on salt fortification.MethodsFor countries with mandatory salt iodization legislation, data from the Global Fortification Data Exchange regarding iodine amounts and iodine compounds, to be added to salt per the country standard and corresponding national salt intake quantities, were compared with 2014 WHO Guidelines.ResultsAs of 4 September 2021, 110 countries with mandatory salt iodization legislation had national salt standards that specified iodine amounts and compounds and salt intake data. All but 1 specified at least 1 recommended iodine compound, but the majority specified higher iodine amounts in salt standards than indicated in the guidelines, taking salt consumption levels into account. Our analysis did not find excess iodine intake as a result; however, we did not have data on the extent of compliance with national salt standards.ConclusionsExisting iodization requirements in salt standards appear to be appropriate for most countries. Countries in which iodine amounts in salt standards are significantly higher than those recommended in the 2014 Guidelines, in particular those with low compliance with national standards or excess iodine intake, may wish to review program process and output indicators and assess whether current iodine amounts in standards would result in excessive intake if implementation was improved.

Ultrasound Image Classification of Thyroid Nodules Based on Deep Learning.

A thyroid nodule, which is defined as abnormal growth of thyroid cells, indicates excessive iodine intake, thyroid degeneration, inflammation, and other diseases. Although thyroid nodules are always non-malignant, the malignancy likelihood of a thyroid nodule grows steadily every year. In order to reduce the burden on doctors and avoid unnecessary fine needle aspiration (FNA) and surgical resection, various studies have been done to diagnose thyroid nodules through deep-learning-based image recognition analysis. In this study, to predict the benign and malignant thyroid nodules accurately, a novel deep learning framework is proposed. Five hundred eight ultrasound images were collected from the Third Hospital of Hebei Medical University in China for model training and validation. First, a ResNet18 model, pretrained on ImageNet, was trained by an ultrasound image dataset, and a random sampling of training dataset was applied 10 times to avoid accidental errors. The results show that our model has a good performance, the average area under curve (AUC) of 10 times is 0.997, the average accuracy is 0.984, the average recall is 0.978, the average precision is 0.939, and the average F1 score is 0.957. Second, Gradient-weighted Class Activation Mapping (Grad-CAM) was proposed to highlight sensitive regions in an ultrasound image during the learning process. Grad-CAM is able to extract the sensitive regions and analyze their shape features. Based on the results, there are obvious differences between benign and malignant thyroid nodules; therefore, shape features of the sensitive regions are helpful in diagnosis to a great extent. Overall, the proposed model demonstrated the feasibility of employing deep learning and ultrasound images to estimate benign and malignant thyroid nodules.

The correlation between iodine nutrition and autoimmunity among hyperthyroid goiter patients in tertiary care hospital of Tamil Nadu

Background: Iodine is a trace element that is essential for the formation of thyroid hormones. It is essential for the human life’s growth and development. The thyroid gland size and functions affected by deficient or excessive intake of iodine. Iodine excess intake was found to associating with iodine-induced hyperthyroidism (IIH) and autoimmune thyroiditis. Aims and Objectives: The present study was to find the hyperthyroid goiter patient nutritional status by urinary iodine excretion (UIE) measurement and correlate them with thyroid hormone and thyroid autoantibodies. Materials and Methods: In this study, 100 adult hyperthyroid goiter ssubjects and 100 apparently normal adult subjects were conveniently recruited in this study.Urinary iodine estimation and serum TSH, fT4, fT3, AMA, and ATG were estimated,which were estimated for case and control groups. Results: The hyperthyroid goiter patient mean UIE concentration was 278.98 μg/L and 68% of excess UIE which was found. There was significant difference in the UIE between the hyperthyroid goiter patient and control (P<0.001). The following types of goiter, based on palpation, were identified among the 100 hyperthyroid patients: Grade I – 4 %, Grade II – 63%, and Grade III – 33%. There were elevated serum AMA levelswith positive correlation of excess iodine for hyperthyroid goiter patient. Conclusion: In this study, there were excess UIEs among patients; hence, these associated complications, namely, benign goiter (14%), thyroiditis (43%), cancer of thyroid (4%), and thyrotoxicosis (39%) were observed.

Epidemiology of Thyroid Cancer.

Epidemiology of Thyroid Cancer.

The Impact of Iodine Concentration Disorders on Health and Cancer.

Iodine deficiency is an ongoing problem. The implementation of salt iodization has significantly reduced the effects of iodine deficiency worldwide in recent years, and the remaining iodine deficiency is mild to moderate. Iodine is an essential substrate for the synthesis of thyroid hormones in the thyroid gland. It can also act as an antioxidant, as well as an anti-proliferative and pro-apoptotic factor. Pregnant women, breastfeeding women, and children are particularly affected by iodine deficiency. It leads to thyroid diseases and metabolic and developmental disorders, as well as cancer. However, an excessive iodine intake may, similarly to iodine deficiency, lead to the development of goiter, and toxic amounts of iodine can lead to thyroiditis, hyperthyroidism, and hypothyroidism, and even to the development of papillary thyroid cancer. Correcting iodine deficiency potentially reduces the chance of developing malignancies. Additional research is needed to better understand both the effect of iodine on carcinogenesis and the clinical outcome of iodine deficiency compensation on cancer patients’ prognosis. The upcoming public health challenge appears to be reducing salt consumption, which could result in a lower iodine intake. Thus, an iodine enrichment vehicle other than salt could be considered if salt iodine levels are not increased to compensate, and urine iodine levels should be monitored more frequently.

The Iodine Rush: Over- or Under-Iodination Risk in the Prophylactic Use of Iodine for Thyroid Blocking in the Event of a Nuclear Disaster.

Iodine is an essential element for the production of thyroid hormones (THs). Both deficient and excess iodine intakes may precipitate in adverse thyroidal events. Radioactive iodine (RI) is a common byproduct of nuclear fission processes. During nuclear emergencies RI may be released in a plume, or cloud, contaminating the environment. If inhaled or ingested, it may lead to internal radiation exposure and the uptake of RI mainly by the thyroid gland that absorbs stable iodine (SI) and RI in the same way. A dose of radiation delivered to the thyroid gland is a main risk factor for the thyroid cancer development. The SI prophylaxis helps prevent childhood thyroid cancer. The thyroid gland saturation with prophylactic SI ingestion, reduces the internal exposure of the thyroid by blocking the uptake of RI and inhibiting iodide organification. However, negative impact of inadequate SI intake must be considered. We provide an overview on the recommended iodine intake and the impact of SI and RI on thyroid in children and adolescents, discussing the benefits and adverse effects of the prophylactic SI for thyroid blocking during a nuclear accident. The use of SI for protection against RI may be recommended in cases of radiological or nuclear emergencies, moreover the administration of iodine for prophylactic purposes should be cautious. Benefits and risks should also be considered according to age. Adverse effects from iodine administration cannot be excluded. Precise indications are mandatory to use the iodine for thyroid blocking. Due to this natural adaption mechanism it’s possible to tolerate large doses of iodine without clinical effects, however, a prolonged assumption of the iodine when not needed can be dangerous and may precipitate in severe thyroidal and non-thyroidal negative effects.

Excessive iodine in iodized household salt in Nepal.

Iodine is an essential trace element required for the regulation of physiological processes involving the thyroid gland. However, inadequate and excessive intake of iodine are responsible for health problems, such as iodine deficiency disorders, hypothyroidism, hyperthyroidism, thyroiditis, thyroid papillary cancer, and thyrotoxicosis. The Universal Salt Iodization (USI) program has become successful in providing supplemental iodine at the population level globally. Packaging quality, fortification level, and transportation and storage conditions of iodized salt determine the availability of iodine. Previous studies have reported severe health issues caused by excessive iodine intake after the implementation of the USI program. To understand the levels of iodine, we collected 2117 household salt samples from seven districts of Nepal and tested them for iodine content; among them, 98.1% were iodized. Overall median concentration of iodine was 53.9ppm (range: 43.5-61.4ppm). The majority (67.2%) of samples had iodine in the range of 45-75ppm. Approximately 0.9% of samples had inadequate, 13.3% contained adequate, and 83.9% had excessive iodine than the World Health Organization-recommended value. Iodine content varied among the sampling districts and seasons, to some extent. Our study confirmed that iodized salt is widely used in Nepal and is excessively iodized. Excessive intake of iodine through iodized salt requires further attention by policy makers. The iodine level may need adjustment to address the health impact.

Overview of Iodine Intake

Iodine is an essential element for human health. Food is the primary source of iodine, but the iodine content of local foods depends on the iodine content of the soil. Therefore, a low iodine concentration in soil and water results in plants and animals with low iodine content. Numerous effects of iodine deficiency on growth and development are known as iodine deficiency disorders. Iodine deficiency has been identified as the most common cause of brain damage in the world and is linked to its effects on infant and child growth and development. Supplementation of table salt with iodine was introduced in the 20th century. Croatia was one of the first countries to introduce the supplementation of table salt with potassium iodide at a concentration of 10 mg/kg in 1953 and 25 mg/kg in 1993. In 2003, the Croatian population reached iodine sufficiency, but given the excessive salt intake (11.6 g/day) and additional sources of iodine in the diet, the question arises, are we consuming too much iodine? This article gives a short overview of iodine intake.

Iodine Concentrations in Conventional and Organic Milk in the Northeastern U.S.

Milk is a major source of dietary iodine in the United States. Due to a relatively low margin of safety for iodine intake, there are concerns for both deficiency and over-exposure. Iodine concentrations of raw milk samples from farms and retail milk in the Northeastern U.S. region were compared between seasons (winter vs. summer) and farming practices (conventional vs. organic). Overall, mean iodine concentration was 46.2% higher in raw milk from conventional farms vs. organic farms. An interaction effect between season and farming practices was observed. Organic raw milk had higher iodine content in the winter than in the summer (423 ± 54 μg/L vs. 273 ± 24 μg/L), whereas conventional raw milk had higher iodine content in the summer than in the winter (618 ± 75 μg/L vs. 398 ± 27 μg/L). Milk samples from conventional farms had 2.27-fold higher average iodine concentration compared to milk coming from organic farms in the summer but did not differ in the winter. Out of 68 and 98 raw milk samples originating from conventional and organic farms, 22 (32.4%) and 19 (19.4%) respectively, had iodine concentrations > 500 µg/L, reaching as high as 1928 μg/L. In contrast, the overall mean concentration of iodine in retail milk did not differ between conventional and organic milk (345 ± 23 vs. 320 ± 42 μg/L, respectively). The current study confirms dairy milk remains to be a good source of iodine to U.S. consumers. However, dairy farms should be aware of the potential adverse health effects of excess iodine intake. Careful considerations in dairy management may be necessary to not exceed the recommended level of iodine supplementation in both conventional and organic operations at the farm level—to maintain optimal iodine concentrations in retail fluid milk accessible to the consumers.

BIOCHEMICAL AND CLINICAL CHARACTERIZATION OF IODINE DEFICIENCY DISORDERS IN CENTRAL INDIA

Background: Iodine (I) is a trace element that is required by both humans and animals. It can be found in a variety of chemical forms, including iodine, iodide (I), and iodate (IO3). It is widely distributed across the earth's ecology, with a concentration in the oceans. Iodine entered the natural cycle from the ocean, the atmosphere, and rainfall, as well as from rainfall into streams and rivers. Iodine is absorbed as iodide in human nutrition. Iodine is a necessary micronutrient and a component of thyroid hormones. Fish and seafood have a high iodine level. The amount of iodine in soil and drinking water varies depending on where it comes from. Iodine shortage produces a variety of negative health consequences, which are referred to as iodine deficiency illnesses (IDD). These conditions are caused by a lack of iodine, which causes insufficient thyroid hormone production.
 Aim: The aim of this study is to characterize the iodine deficiency disorder by biochemical and clinical assessment and to correlate the iodine status with thyroid disorder(s) in adults.
 Material and Method: The samples for this investigation were taken from patients at the Department of Endocrine Surgery. This study comprised a total of 100 hundred goiter patients, who had their urinary iodine excretion and thyroid hormone levels examined. For all goiter patients, the grading of goitre was established using the WHO/UNICEF/ICCIDD approved criteria. TSH, Free T4, Free T3 by using ELISA Method using commercial kits. Anti-microsomal antibody (AMA) or Thyroperoxidase antibody (TPO-Ab) by using ELISA Method using commercial kits. Anti-thyroglobulin antibody (ATG) estimated by using ELISA Method using commercial kits.
 Results: The data for each group were presented as Median and inter quarter range (IQR) The median and IQR of Urinary iodine excretion of the hypothyroid, hyperthyroid and Euthyroid goiter subjects were respectively and there was significant difference in the median urinary iodine excretion. The median and IQR of Urinary iodine excretion of the thyroiditis, thyrotoxicosis, cancer of thyroid and benign goiter respectively and there was significant difference in the median urinary iodine excretion.
 Conclusion: For ages, endemic goitre and cretinism have been recognised as public health issues, and iodine deficiency is thought to be the leading cause of preventable mental retardation. Most countries now include iodine deficiency control as part of their national nutrition policies. To eliminate iodine deficiency, several therapies with high efficacy have been employed, including iodized oil capsules (IOC) and universal salt iodisation (USI). Although some progress has been made, efforts to eliminate this devastating health problem must be hastened. Not only should iodine deficiency be monitored, but so should excessive iodine intake, as this is a problem in various areas, including the camps.
 Keywords: IDD, Goitre, TSH, IOC, USI, ATG, AMA, T4, T3.

Study the correlation of iodine nutrition and autoimmunity among Euthyroid goiter patient in a tertiary care hospital in Tamil Nadu

Background: Iodine is an essential micronutrient for the thyroid hormone synthesis. It is crucial for the growth and development of human life. Deficient or excessive iodine intake may affect thyroid gland size and functions. Despite the intake of iodized salt, the increasing occurrence of thyroid disorders in India.
 Aim and Objective: Aim of the present study is to analyse the nutritional status of iodine among Euthyroid goiter patient by measuring urinary excretion and correlate with thyroid hormone and auto antibodies
 Materials and Methods: one hundred and fifty Euthyroid goiter patients and one hundred and fifty age-matched normal adult were included in study. Urinary Iodine level and serum TSH, freeT4, freeT3, AMA and ATG were estimated both case and control groups.
 Results: The mean urinary iodine excretion concentration (UIC) in Euthyroid goiter patient was 244.39 µg/L and excess urinary iodine excretion was found in 48%. There were elevated serum AMA levels in Euthyroid goiter patient and that positive correlated with excess iodine.
 Conclusion: In this study we found that excess urinary iodine excretion among patients. This study we observed iodine excess associated complications, viz., benign goiter (49%), thyroiditis (24%), cancer of thyroid (21%) and thyrotoxicosis (6%).

Iodine nutrition level and thyroid function in pregnant women in the Yongchuan district of Chongqing

This study aims to investigate thyroid function-associated parameters and the incidence of thyroid disorders in pregnant women, with the overarching aim to ensure that pregnant women do not develop said disorders due to aberrant iodine levels during the course of pregnancy. A total of 300 pregnant women who underwent routine check-ups at the Yongchuan Hospital Affiliated to Chongqing Medical University from January to December 2021 were enrolled. Venous blood and morning urine were collected. Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were determined by chemiluminescence immunoassay. Urinary iodine concentration (UIC) was detected by arsenic cerium catalytic spectrophotometry. Thyroid disorders were extrapolated from the measured parameters. The overall median UIC was 203 μg/L, which was within normal range. Subgroup analysis revealed that the median UIC in the first trimester was 187.5 μg/L, 211.8 μg/L in the second trimester, and 239.9 μg/L in the third trimester. However, based on the WHO criteria, 32%, 30%, and 18% of pregnant women were iodine deficient during their first, second, and third trimester, respectively. The proportion of women with iodine deficiency in the first and second trimesters was higher compared to the third trimester (P < 0.05). Serum FT3 and FT4 concentrations were higher in subjects in their first and second trimester versus the third trimester, while serum TSH levels were lower in subjects in their first and second trimester versus the third trimester (P < 0.05). The TSH concentration in subjects with inadequate iodine intake (UIC < 150 μg/L) was lower compared to subjects with adequate iodine intake (UIC 150 - 249 μg/L), but higher than in subjects with more than adequate intake (UIC 250 - 499 μg/L) and excess iodine intake (UIC ≥ 500 μg/L) (P < 0.05). TSH concentration and UIC were positively correlated (r = 0.1945, P = 0.0007), while no relationship was observed between UIC and FT3 and FT4 serum levels (r1 = -0.0593, P1 = 0.3053; r2 = -0.0149, P2 = 0.7968). There was no significant difference in FT3 and FT4 concentration between different UIC strata (P > 0.05). The incidence of thyroid disease during pregnancy in iodine-deficient women was greater compared to pregnant women with adequate iodine intake (P < 0.05) and higher in subjects in the more than adequate as well as excessive iodine intake cohorts (P < 0.05). The iodine nutritional intake by pregnant women in Yongchuan District, Chongqing, was generally sufficient to meet developmental and metabolic needs. However, about a third of women in their first and second trimester exhibited iodine deficiency. Iodine deficiency was associated with an increased incidence of thyroid diseases. In clinical practice, the UIC of pregnant women should be measured during key stages in the pregnancy to prevent the manifestation of thyroid diseases.

Studies on urinary excretion and variability of dietary iodine in healthy Japanese adults.

The daily consumption of iodine in Japan is higher than in most countries, and there are few reports on iodine metabolism and variance of habitual iodine ingestion in an iodine-sufficient area. To elucidate the patterns of short-term urinary iodine excretion (UIE) and long-term variability of habitual iodine intake, the urinary iodine excretion process after a high dietary iodine load of 3 mg was observed in eight Japanese adults under strict supervision with complete urine collections for three days. In addition, estimated UIE and dietary iodine intake (DII) were assessed in 24 university students using repeated spot urine samples of ten consecutive days and a food frequency questionnaire in each of the four seasons. Approximately 50, 75 and 90% of orally ingested iodine was excreted into the urine at 8, 13 and 22 hours after ingestion, respectively. Almost an equal amount of ingested iodine in meals was cleared within 33.5 h after eating with a maximum excretion rate at 3-4 h. There was a high fluctuation in the UIE and DII in the university students. The intra- and inter-individual crude coefficients of variation were 123 or 294.7% for UIE, and 58.3 or 88.7% for DII, respectively, indicating a higher variance of habitual iodine intake than in other countries. The frequency of occurrence for UIE above 3 mg was every 43 days. Rapid renal clearance of iodine and high variability as well as low frequency of dietary iodine intake might prevent people from being exposed to an excess iodine intake over the long term in Japan.

Establishment of an iodine model for prevention of iodine-excess-induced thyroid dysfunction in pregnant women.

This study aims to explore the relationship between the iodine status and thyroid dysfunction (TD) in pregnant women and establish a model to guide them to prevent excessive iodine intake. A total of 515 pregnant women were enrolled in the study. Urinary iodine concentration (UIC), thyroid hormones, and thyroid autoantibodies were measured, and then a logistic regression model was established. The median UIC of pregnant women was 174 ± 120 μg/L. Multivariate logistic regression analysis indicated that multivitamin supplements containing iodine and frequent seafood consumption were risk factors for excessive iodine (UIC ≥500 μg/L). Besides, excessive iodine was a risk factor for TD. Iodine excess was associated with a high prevalence of TD in pregnant women, especially TPOAb-positive women (P < 0.05). A logistic regression model based on potential risk factors was established to predict the risk of excessive iodine intake among pregnant women and provide guidance to minimize the risk of excessive iodine intake, thus reducing the risk of TD.

Is Dietary Iodine Intake Excessive According to the Theoretical Model of Healthy Dietary Intake Pattern in Pregnant Women and Schoolchildren: Water, Salt, or Food?

Introduction: Iodine deficiency during pregnancy can cause hypothyroidism and goiter; in schoolchildren, it can cause reduced intelligence quotient. In excess, iodine can cause thyroiditis, goiter, and Hashimoto's hypothyroidism. Currently, schoolchildren and pregnant women are classified as risk groups for excessive iodine intake and iodine deficiency, respectively. Thus, determining iodine from all sources of consumption is important for intervention planning.Objective: To construct a theoretical model for the iodine intake of schoolchildren and pregnant women of a city in the Zona da Mata Mineira region, considering a healthy diet, salt consumption and water intake.Methodology: The dietary iodine intake of pregnant women was analyzed based on a dietary iodine table compiled from an international database. A dietary plan was prepared following the Brazilian Food Guide. Iodine concentration of different salt brands sold in local establishments was checked, and drinking water samples from healthcare facilities were analyzed. A descriptive and exploratory statistical analysis was performed and the results were presented in absolute and relative frequencies, and measures of central tendency and dispersion.Results: According to the proposed diet, pregnant women and schoolchildren would have a daily intake of 71.6 μg and 71 μg, respectively. Thirteen salt brands were evaluated, 69.2% complied with the legislation and the mean iodine content was 29.88 mg. The mean concentration of iodine in water was 25 μg iodine/liter and 14 μg iodine/liter, respectively, in summer and autumn. Considering the intake of food, salt, and drinking water according to the proposed dietary plan, the daily intake for pregnant women would be 279.5 and 253.5 μg for schoolchildren.Conclusion: The daily iodine intake of schoolchildren and pregnant women according to this theoretical model was excessive, considering a healthy dietary pattern. This theoretical model can guide actions and public policies aimed at targeting all forms of iodine intake.

Nationwide Representative Survey of Dietary Iodine Intake and Urinary Excretion in Postpartum Korean Women.

Iodine is an essential component of thyroid hormones, but excessive iodine intake can lead to thyroid dysfunction. Traditionally, Korean mothers consume brown seaweed soup (miyeokguk), a high source of iodine, after childbirth. There is controversy regarding the effects of excessive postpartum iodine intake on the health of mothers and infants. Thus far, there have been no nationwide large-scale surveys regarding the status of iodine intake among postpartum women in Korea. Therefore, we conducted a nationwide survey of postpartum dietary iodine intake among Korean women. In total, 1054 Korean women aged ≥19 years, at less than 8 weeks postpartum, participated in this survey. Dietary data were collected using self-reported 2-day dietary records, along with before-and-after meal photos. To evaluate the correlation between dietary iodine and urinary iodine excretion (UIE), spot urine, and 24 h urine samples were collected from 98 and 29 participants, respectively. The mean daily iodine intake among all participants was 2945.6 μg, and it gradually decreased over time after childbirth. Dietary iodine intake was significantly correlated with 24 h UIE (r = 0.396, p < 0.05) and spot urine UIE (r = 0.312, p < 0.05). Follow-up studies are required to examine the influence of excessive postpartum iodine intake on thyroid health in mothers and their infants.

Adaptation to a High Iodine Intake in Greenland Inuit Suggested by Thyroid Disease Pattern.

Objective: Arctic living is influenced by cold winters, short summers, and excessive iodine intake from the traditional Inuit diet providing for habitation of the Arctic for centuries. This is changing and we surveyed thyroid function in populations living in Greenland. Design: Population-based cross-sectional study. Methods: Data were collected in the capital city in West Greenland and in rural East Greenland. Information on lifestyle, dietary habits, and medical history was obtained using questionnaires. Thyrotropin, free thyroxine, free triiodothyronine, thyroglobulin, and thyroglobulin antibody were measured in serum, iodine, and creatinine in spot urine samples. Results: One percent of the Greenlandic population was invited and 535 participated with an overall participation rate of 95%. Iodine excretion was 225 μg/24 hours in East Greenland and 169 μg/24 hours among West Greenland Inuit. Hyperthyroidism occurred in 10.7% of West Greenlandic Inuit (men/women: 4.3%/16.3%) and 7.8% of East Greenlandic Inuit (3.8%/12.8%). Hypothyroidism was found in 2.7% in West Greenland (0.0%/5.0%) and 5.6% (5.6%/5.6%) in East Greenland. Conclusion: Hyperthyroidism was frequent among Inuit and the occurrence of hypothyroidism was low. The pattern of hyper- and hypothyroidism among Greenlandic Inuit with adequate iodine intake was comparable with those seen in populations with iodine deficiency. Inuit may thus have adapted to excessive iodine intake over centuries, causing a need for a higher iodine intake to prevent iodine deficiency disorders.

Iodine intake level and incidence of thyroid disease in adults in Shaanxi province: a cross-sectional study.

BackgroundExploring the relationship between adult iodine intake level and thyroid disease in Shaanxi area is of great significance for adult scientific iodine supplement and individual iodine supplement strategy. At present, the relationship between iodine and incidence of thyroid disease has not been determined.MethodsThis study was based on the clinical data of 1,159 patients from the Shaanxi Province aged over 18 years and diagnosed with thyroid-related diseases who were admitted to the Xijing Hospital from 2016 to 2020, and 182 provincial healthy volunteers aged over 18 years who agreed and signed informed consent for physical examination in 2020. The chi-square test and nonparametric test were used to investigate the relationship between iodine intake level and thyroid disease.Results(I) A total of 1,341 patients were enrolled and observed in this study. The median urinary iodine (MUI) was 233.20 μg/L. Compared with the control, group participants the urine iodine (UI) of those with hyperthyroidism, Hashimoto’s thyroiditis (HT), papillary thyroid cancer (PTC), and benign nodules was significantly different (P<0.05). (II) The incidence of PTC was higher in women with excessive iodine intake and people aged ≥45 years (P<0.05). (III) There was no significant difference in urinary iodine (UI), age, gender, and other factors between benign nodules and PTC (P>0.05).ConclusionsThe iodine intake level of adults in Shaanxi is high, which is related to hyperthyroidism, HT, benign nodules, thyroid cancer, and other diseases. There were 3 factors, including excessive iodine intake, age ≥45 years, and female gender, found to be associated with the development of PTC.

Iodine excess induces hepatic, renal and pancreatic injury in female mice as determined by attenuated total reflection Fourier-transform infrared spectrometry.

Limited knowledge of the long-term effects of excessive iodine (EI) intake on biomolecular signatures in the liver/pancreas/kidney prompted this study. Herein, following 6 months of exposure in mice to 300, 600, 1200 or 2400 μg/L iodine, the biochemical signature of alterations to the liver/pancreas/kidney was profiled using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy coupled with principal component analysis-linear discriminant analysis (PCA-LDA). Our research showed that serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), serum creatinine (Scr), insulin, blood glucose levels and homeostasis model assessment for insulin resistance (HOMA-IR) index in the 1200 and 2400 μg/L iodine-treated groups were significantly increased compared with those in the control group. Moreover, histological analysis showed that the liver/kidney/pancreas tissues of mice exposed to EI treatment displayed substantial morphological abnormalities, such as a loss of hepatic architecture, glomerular cell vacuolation and pancreatic neutrophilic infiltration. Notably, EI treatment caused distinct biochemical signature segregation between EI-exposed versus the control liver/pancreas/kidney. The main biochemical alterations between EI-exposed and control groups were observed for protein phosphorylation, protein secondary structures and lipids. The ratios of amide I-to-amide II (1674 cm-1 /1570 cm-1 ), α-helix-to-β-sheet (1657 cm-1 /1635 cm-1 ), glycogen-to-phosphate (1030 cm-1 /1086 cm-1 ) and the peptide aggregation (1 630 cm-1 /1650 cm-1 ) level of EI-treated groups significantly differed from the control group. Our study demonstrated that EI induced hepatic, renal and pancreatic injury by disturbing the structure, metabolism and function of the cell membrane. This finding provides the new method and implication for human health assessment regarding long-term EI intake.

Age-specific thyrotropin references decrease over-diagnosis of hypothyroidism in elderly patients in iodine-excessive areas.

Acute or chronic exposure to excess iodine has detrimental effects on thyroid physiology; therefore, this study aimed to determine the prevalence of overt hypothyroidism (OH) and subclinical hypothyroidism (SCH) in an elderly population residing in geographical areas with chronic exposure to excess iodine intake and to analyse contributing risk factors. This cross-sectional study was conducted from 2016 to 2017 in areas of Jiangsu Province that have documented chronic exposure to high iodine intake. We enroled 2559 adult participants using a multistage, stratified sampling method. Urinary iodine concentration (UIC), serum thyroid-stimulating hormone (TSH) level and other relevant parameters were measured. Demographic information was recorded using a standardized questionnaire. The age-specific TSH references were determined by the National Academy of Clinical Biochemistry guidelines. Univariate and multivariate logistic regression analyses were performed to identify risk factors for hypothyroidism in the study population. The median UIC of participants was 307.3 µg/L (interquartile range: 200.7, 469.8 μg/L). The prevalence of OH in subjects ≥70 years using laboratory reference ranges was 2.37%; however, it decreased to 1.78% with the use of an age-specific reference range. Similarly, the prevalence of SCH also declined drastically from 29.59% to 2.96% with the application of an age-specific reference range. In both univariate and multivariate models, advanced age, female gender and high UIC were identified as risk factors for hypothyroidism. Usage of age-specific TSH reference ranges led to a significantly lower prevalence of OH and SCH in the study population, thus preventing unnecessary over-diagnosis and over-treatment.