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Oglio R, Rodriguez C, Salvarredi L, Rossich L, Perona M, Dagrosa A, Juvenal G, Thomasz L. Selenium bioavailability modulates the sensitivity of thyroid cells to iodide excess. Chem Biol Interact 2024; 387:110810. [PMID: 38013145 DOI: 10.1016/j.cbi.2023.110810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/25/2023] [Accepted: 11/15/2023] [Indexed: 11/29/2023]
Abstract
INTRODUCTION Iodide is an essential micronutrient for the synthesis of thyroid hormones and its imbalance is involved in the origin of different thyroid pathological processes. Selenium (Se) is another essential trace element that contributes to thyroid preservation through the control of the redox homeostasis. Different studies have demonstrated that sodium-iodide-symporter (NIS) is downregulated in the presence of iodide excess and Se supplementation reverses this effect. We also demonstrated that NOX4-derived ROS are involved in NIS repression induced by iodide excess. The aim of this study was to investigate how Se bioavailability is decisive in the sensitivity to iodide excess on a differentiated rat thyroid cell line (FRTL-5). RESULTS We demonstrated that siRNA-mediated silencing of Nox4 suppressed AKT phosphorylation induced by iodide excess. Iodide increases TGF-β1 mRNA expression, AKT phosphorylation, ROS levels and decreases GPX1 and TXRND1 mRNAs expression while Se reversed these effects. Furthermore, iodide induced Nrf2 transcriptional activity only in Se-supplemented cultures, suggesting that Se positively influences Nrf2 activation and selenoenzyme response in FRTL-5. Se, also inhibited NF-κB phosphorylation induced by iodide excess. In addition, we found that iodide excess decreased total phosphatase activity and PTP1B and PTEN mRNA expression. Se supply restored only PTEN mRNA expression. Finally, we studied the 2-α-iodohexadecanal (2-IHD) effects since it has been proposed as intermediary of iodide action on thyroid autoregulation. 2-IHD stimulated PI3K/AKT activity and reduced NIS expression by a ROS-independent mechanism. Also, we found that 2-IHD increased TGF-β1 mRNA and TGF-β inhibitor (SB431542) reverses the 2-IHD inhibitory effect on NIS mRNA expression, suggesting that TGF-β1 signaling pathway could be involved. Although Se reduced 2-IHD-induced TGFB1 levels, it could not reverse its inhibitory effect on NIS expression. CONCLUSION Our study suggests that Se bioavailability may improve the expression of antioxidant genes through the activation of Nrf2, interfere in PI3K/AKT signaling and NIS expression by redox modulation.
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Affiliation(s)
- Romina Oglio
- Nuclear Biochemistry Division, Argentine National Atomic Energy Commission, Buenos Aires, Argentina
| | - Carla Rodriguez
- Nuclear Biochemistry Division, Argentine National Atomic Energy Commission, Buenos Aires, Argentina
| | - Leonardo Salvarredi
- FUESMEN, Mendoza, Argentina; Balseiro Institute, National University of Cuyo, Mendoza, Argentina
| | - Luciano Rossich
- Nuclear Biochemistry Division, Argentine National Atomic Energy Commission, Buenos Aires, Argentina
| | - Marina Perona
- Nuclear Biochemistry Division, Argentine National Atomic Energy Commission, Buenos Aires, Argentina; CONICET, Buenos Aires, Argentina
| | - Alejandra Dagrosa
- Nuclear Biochemistry Division, Argentine National Atomic Energy Commission, Buenos Aires, Argentina; CONICET, Buenos Aires, Argentina
| | - Guillermo Juvenal
- Nuclear Biochemistry Division, Argentine National Atomic Energy Commission, Buenos Aires, Argentina; CONICET, Buenos Aires, Argentina
| | - Lisa Thomasz
- Nuclear Biochemistry Division, Argentine National Atomic Energy Commission, Buenos Aires, Argentina; CONICET, Buenos Aires, Argentina.
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Shan Q, Liu Q, He Y. Age-dependent association of high urinary iodine concentration with major depression in adults: NHANES 2007-2020. J Affect Disord 2023; 340:189-196. [PMID: 37562559 DOI: 10.1016/j.jad.2023.08.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 07/03/2023] [Accepted: 08/03/2023] [Indexed: 08/12/2023]
Abstract
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.
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Affiliation(s)
- Qingsong Shan
- Department of Statistics, Jiangxi University of Finance and Economics, No.168, East Shuanggang Road, Nanchang, 330013, Jiangxi, China
| | - Qianning Liu
- Department of Statistics, Jiangxi University of Finance and Economics, No.168, East Shuanggang Road, Nanchang, 330013, Jiangxi, China.
| | - Yajie He
- Department of Statistics, Jiangxi University of Finance and Economics, No.168, East Shuanggang Road, Nanchang, 330013, Jiangxi, China
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Pinto CA, Filomeno Fontes EA, Crispim SP, Vieira Ribeiro SA, Franceschini SDCC, Pizato N, Rocha de Faria F, Pereira RJ, Abreu de Carvalho C, Carmo Rodrigues Barbosa M, Sperandio N, de Souza Macedo M, Priore SE. Iodine Concentration in Brazilian Drinking Water and Its Possible Contribution to Iodine Intake for Different Physiological Groups. J Nutr Metab 2022; 2022:7542632. [PMID: 36590239 DOI: 10.1155/2022/7542632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 10/06/2022] [Accepted: 10/22/2022] [Indexed: 12/24/2022] Open
Abstract
Objective The objective is to analyze the concentration of iodine in Brazilian drinking water and its possible contribution to iodine intake for different groups. Methods Water samples collected from primary healthcare units in eight locations distributed across all five macroregions of Brazil were analyzed. The quantification of iodine in the water samples was done by spectrophotometry (leuco crystal violet method). To classify the degree of iodine concentration, the recommendation of the Ministry of Health (China) was followed since Brazil lacks a classification standard. To verify the possible contribution of drinking water to iodine intake for different groups, the recommended water intake for each group according to the United States Institute of Medicine (2004) was considered. The percentage of iodine in drinking water and its contribution to iodine intake for different physiological groups were calculated based on the estimated average requirement (EAR) of iodine. A descriptive statistical analysis was performed using SPSS version 21.0 and Statistical Analysis Systems (SAS) version 9.2. Results Significant differences were found between the maximum and minimum concentrations of iodine in water samples from the same location. In Pinhais (south region), the difference was 44.32 μg· L-1; in Viçosa (southeast region), it was 27.86 μg·L-1; in Rondonópolis (midwest region), it was 12.66 μg·L-1; in São Luís (northeast region), it was 11.82 μg·L-1; in Brasilian Federal District (midwest region), it was 10.98 μg·L-1; in Macaé (southeast region), it was 10.14 μg· L-1; in Palmas (north region), it was 4.22 μg·L-1; and in Vitória (southeast region), it was 1.69 μg·L-1. The maximum concentrations of iodine found in the drinking water of Pinhais and Viçosa can contribute more than 70.0% and 50.0%, respectively, to daily iodine intake for all groups. Conclusion Monitoring the concentration of iodine in drinking water from different locations in each city or Federal District is a preventive measure against inadequate iodine intake and possible adverse changes in population health.
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Ma R, Yan M, Han P, Wang T, Li B, Zhou S, Zheng T, Hu Y, Borthwick AGL, Zheng C, Ni J. Deficiency and excess of groundwater iodine and their health associations. Nat Commun 2022; 13:7354. [PMID: 36446773 PMCID: PMC9708681 DOI: 10.1038/s41467-022-35042-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 11/16/2022] [Indexed: 11/30/2022] Open
Abstract
More than two billion people worldwide have suffered thyroid disorders from either iodine deficiency or excess. By creating the national map of groundwater iodine throughout China, we reveal the spatial responses of diverse health risks to iodine in continental groundwater. Greater non-carcinogenic risks relevant to lower iodine more likely occur in the areas of higher altitude, while those associated with high groundwater iodine are concentrated in the areas suffered from transgressions enhanced by land over-use and intensive anthropogenic overexploitation. The potential roles of groundwater iodine species are also explored: iodide might be associated with subclinical hypothyroidism particularly in higher iodine regions, whereas iodate impacts on thyroid risks in presence of universal salt iodization exhibit high uncertainties in lower iodine regions. This implies that accurate iodine supply depending on spatial heterogeneity and dietary iodine structure optimization are highly needed to mitigate thyroid risks in iodine-deficient and -excess areas globally.
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Affiliation(s)
- Ruoqi Ma
- grid.11135.370000 0001 2256 9319College of Environmental Sciences and Engineering, Peking University; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871 P. R. China ,grid.11135.370000 0001 2256 9319Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055 P.R. China ,grid.453103.00000 0004 1790 0726General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Resources, Beijing, 100120 P. R. China
| | - Mingquan Yan
- grid.11135.370000 0001 2256 9319College of Environmental Sciences and Engineering, Peking University; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871 P. R. China
| | - Peng Han
- grid.11135.370000 0001 2256 9319College of Environmental Sciences and Engineering, Peking University; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871 P. R. China
| | - Ting Wang
- grid.11135.370000 0001 2256 9319College of Environmental Sciences and Engineering, Peking University; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871 P. R. China ,grid.11135.370000 0001 2256 9319State Environmental Protection Key Laboratory of All Materials Fluxes in River Ecosystems, Peking University, Beijing, 100871 P. R. China
| | - Bin Li
- grid.11135.370000 0001 2256 9319College of Environmental Sciences and Engineering, Peking University; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871 P. R. China ,grid.11135.370000 0001 2256 9319State Environmental Protection Key Laboratory of All Materials Fluxes in River Ecosystems, Peking University, Beijing, 100871 P. R. China
| | - Shungui Zhou
- grid.256111.00000 0004 1760 2876Provincial Key Laboratory of Soil Environment Health and Regulation, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
| | - Tong Zheng
- grid.11135.370000 0001 2256 9319College of Environmental Sciences and Engineering, Peking University; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871 P. R. China
| | - Yandi Hu
- grid.11135.370000 0001 2256 9319College of Environmental Sciences and Engineering, Peking University; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871 P. R. China
| | - Alistair G. L. Borthwick
- grid.4305.20000 0004 1936 7988Institute of Infrastructure and Environment, School of Engineering, The University of Edinburgh, Edinburgh, EH9 3JL UK ,grid.11201.330000 0001 2219 0747School of Engineering, Mathematics and Computing, University of Plymouth, Plymouth, PL8 4AA UK
| | - Chunmiao Zheng
- grid.263817.90000 0004 1773 1790State Environmental Protection Key Laboratory for Integrated Control of Groundwater and Surface Water Pollution in Watershed, Southern University of Science and Technology, Shenzhen, 518055 P. R. China
| | - Jinren Ni
- grid.11135.370000 0001 2256 9319College of Environmental Sciences and Engineering, Peking University; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871 P. R. China ,grid.11135.370000 0001 2256 9319Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055 P.R. China
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Jomova K, Makova M, Alomar SY, Alwasel SH, Nepovimova E, Kuca K, Rhodes CJ, Valko M. Essential metals in health and disease. Chem Biol Interact 2022; 367:110173. [PMID: 36152810 DOI: 10.1016/j.cbi.2022.110173] [Citation(s) in RCA: 131] [Impact Index Per Article: 65.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/10/2022] [Accepted: 09/05/2022] [Indexed: 11/03/2022]
Abstract
In total, twenty elements appear to be essential for the correct functioning of the human body, half of which are metals and half are non-metals. Among those metals that are currently considered to be essential for normal biological functioning are four main group elements, sodium (Na), potassium (K), magnesium (Mg), and calcium (Ca), and six d-block transition metal elements, manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn) and molybdenum (Mo). Cells have developed various metallo-regulatory mechanisms for maintaining a necessary homeostasis of metal-ions for diverse cellular processes, most importantly in the central nervous system. Since redox active transition metals (for example Fe and Cu) may participate in electron transfer reactions, their homeostasis must be carefully controlled. The catalytic behaviour of redox metals which have escaped control, e.g. via the Fenton reaction, results in the formation of reactive hydroxyl radicals, which may cause damage to DNA, proteins and membranes. Transition metals are integral parts of the active centers of numerous enzymes (e.g. Cu,Zn-SOD, Mn-SOD, Catalase) which catalyze chemical reactions at physiologically compatible rates. Either a deficiency, or an excess of essential metals may result in various disease states arising in an organism. Some typical ailments that are characterized by a disturbed homeostasis of redox active metals include neurological disorders (Alzheimer's, Parkinson's and Huntington's disorders), mental health problems, cardiovascular diseases, cancer, and diabetes. To comprehend more deeply the mechanisms by which essential metals, acting either alone or in combination, and/or through their interaction with non-essential metals (e.g. chromium) function in biological systems will require the application of a broader, more interdisciplinary approach than has mainly been used so far. It is clear that a stronger cooperation between bioinorganic chemists and biophysicists - who have already achieved great success in understanding the structure and role of metalloenzymes in living systems - with biologists, will access new avenues of research in the systems biology of metal ions. With this in mind, the present paper reviews selected chemical and biological aspects of metal ions and their possible interactions in living systems under normal and pathological conditions.
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Affiliation(s)
- Klaudia Jomova
- Department of Chemistry, Faculty of Natural Sciences and Informatics, Constantine The Philosopher University in Nitra, 949 01, Nitra, Slovakia
| | - Marianna Makova
- Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, 812 37, Bratislava, Slovakia
| | - Suliman Y Alomar
- King Saud University, Zoology Department, College of Science, Riyadh, 11451, Saudi Arabia
| | - Saleh H Alwasel
- King Saud University, Zoology Department, College of Science, Riyadh, 11451, Saudi Arabia
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, 50003 Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, 50003 Hradec Kralove, Czech Republic; Biomedical Research Center, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | | | - Marian Valko
- Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, 812 37, Bratislava, Slovakia; King Saud University, Zoology Department, College of Science, Riyadh, 11451, Saudi Arabia.
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Winder M, Kosztyła Z, Boral A, Kocełak P, Chudek J. The Impact of Iodine Concentration Disorders on Health and Cancer. Nutrients 2022; 14:2209. [PMID: 35684009 DOI: 10.3390/nu14112209] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/22/2022] [Accepted: 05/23/2022] [Indexed: 01/27/2023] Open
Abstract
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.
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Li F, Wan S, Zhang L, Li B, He Y, Shen H, Liu L. A Meta-Analysis of the Effect of Iodine Excess on the Intellectual Development of Children in Areas with High Iodine Levels in their Drinking Water. Biol Trace Elem Res 2022; 200:1580-1590. [PMID: 34302270 DOI: 10.1007/s12011-021-02801-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/19/2021] [Indexed: 11/27/2022]
Abstract
The purpose of this meta-analysis is to comprehensively investigate the effect of iodine excess on children's intellectual development in areas with high iodine levels in their drinking water. We systematically searched the electronic databases and identified 17 publications (16 in Chinese and 1 in English) on the effect of iodine excess on children's intelligence published between January 31, 1985, and January 31, 2020. This meta-analysis included 14,794 children from 28 studies. The results showed that compared with the control group, the intelligence level of children in the high iodine group reduced significantly by 1.64 points (WMD=-1.64; 95% CI (-3.225, -0.049), Z=2.02, P<0.05). Subgroup analyses were performed according to the water iodine concentration, water iodine concentration of the control group, the intelligence test method, and regions of China (i.e., north and south). We noted that when the water iodine concentration was <300μg/L, 301-600μg/L, 600.1-900μg/L, and >900μg/L, the intelligence level of the high iodine groups decreased by varying degrees, although not statistically significant (all P>0.05). The water iodine concentration of the control group was divided into two groups (<150 μg/L and <100 μg/L) and the heterogeneity analysis showed that the heterogeneity of the control group decreased significantly when the concentration of water iodine was <150 μg/L, I2 = 67.3%, P<0.001, which indicated a potential source of heterogeneity. The analyses by test method showed that among the studies which used the China Joint Raven's test, the intelligence level of children in the high iodine group was 0.86 points lower than in the control group (P>0.05). Conversely, we observed that among the studies which used the China Binet intelligence test and the binaphthalene intelligence test of Tanzhida in Japan to evaluate children's intelligence level, the intelligence level of children in the high iodine groups was significantly lower (3.65 points and 8.0 points, respectively) compared with the control groups (P<0.05). The analysis of the regions of China demonstrated that whereas the reduction in children's intelligence level from excess iodine in the north of China was not statistically significant (WMD=-0.16, 95% CI (-2.18, 1.85), P>0.05), the association was statistically significant in the southern part of China (WMD=-1.86, 95% CI (-3.57, -0.09), P<0.05). This study found that high iodine concentration was statistically significantly associated with a decline in intelligence level in children. Comparatively, the intelligence level of children who were exposed to high iodine concentrations reduced significantly by 1.64 points. These findings have public health implications.
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Affiliation(s)
- Fan Li
- National Health commission &Education Bureau of Heilongjiang province, Key laboratory and Etiology and Epidemiology, Key Laboratory of Trace Elements and Human Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China
| | - Siyuan Wan
- National Health commission &Education Bureau of Heilongjiang province, Key laboratory and Etiology and Epidemiology, Key Laboratory of Trace Elements and Human Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China
- Department of Preventive Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang, China
| | - Li Zhang
- National Health commission &Education Bureau of Heilongjiang province, Key laboratory and Etiology and Epidemiology, Key Laboratory of Trace Elements and Human Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China
| | - Baoxiang Li
- National Health commission &Education Bureau of Heilongjiang province, Key laboratory and Etiology and Epidemiology, Key Laboratory of Trace Elements and Human Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China
| | - Yanhong He
- National Health commission &Education Bureau of Heilongjiang province, Key laboratory and Etiology and Epidemiology, Key Laboratory of Trace Elements and Human Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China
| | - Hongmei Shen
- National Health commission &Education Bureau of Heilongjiang province, Key laboratory and Etiology and Epidemiology, Key Laboratory of Trace Elements and Human Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China
| | - Lixiang Liu
- National Health commission &Education Bureau of Heilongjiang province, Key laboratory and Etiology and Epidemiology, Key Laboratory of Trace Elements and Human Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China.
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Farebrother J, Zimmermann MB, Andersson M. Excess iodine intake: sources, assessment, and effects on thyroid function. Ann N Y Acad Sci 2019; 1446:44-65. [PMID: 30891786 DOI: 10.1111/nyas.14041] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/30/2019] [Accepted: 02/02/2019] [Indexed: 12/15/2022]
Abstract
Iodine is essential for thyroid hormone synthesis. High iodine intakes are well tolerated by most healthy individuals, but in some people, excess iodine intakes may precipitate hyperthyroidism, hypothyroidism, goiter, and/or thyroid autoimmunity. Individuals with preexisting thyroid disease or those previously exposed to iodine deficiency may be more susceptible to thyroid disorders due to an increase in iodine intake, in some cases at intakes only slightly above physiological needs. Thyroid dysfunction due to excess iodine intake is usually mild and transient, but iodine-induced hyperthyroidism can be life-threatening in some individuals. At the population level, excess iodine intakes may arise from consumption of overiodized salt, drinking water, animal milk rich in iodine, certain seaweeds, iodine-containing dietary supplements, and from a combination of these sources. The median urinary iodine concentration (UIC) of a population reflects the total iodine intake from all sources and can accurately identify populations with excessive iodine intakes. Our review describes the association between excess iodine intake and thyroid function. We outline potential sources of excess iodine intake and the physiological responses and consequences of excess iodine intakes. We provide guidance on choice of biomarkers to assess iodine intake, with an emphasis on the UIC and thyroglobulin.
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Affiliation(s)
- Jessica Farebrother
- Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland.,Department of Women and Children's Health, King's College London, London, UK
| | - Michael B Zimmermann
- Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland.,Iodine Global Network, Ottawa, Ontario, Canada
| | - Maria Andersson
- Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland.,Iodine Global Network, Ottawa, Ontario, Canada.,Division of Gastroenterology and Nutrition, University Children's Hospital Zurich, Zurich, Switzerland
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Sarkar D, Chakraborty A, Saha A, Chandra AK. Iodine in excess in the alterations of carbohydrate and lipid metabolic pattern as well as histomorphometric changes in associated organs. J Basic Clin Physiol Pharmacol 2019; 29:631-643. [PMID: 30067510 DOI: 10.1515/jbcpp-2017-0204] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 05/17/2018] [Indexed: 01/24/2023]
Abstract
Background Iodine is a nonpareil constituent of thyroid hormones (THs) and a prime regulator of thyroid gland functioning. Although essential at recommended levels for the prevention of iodine deficiency disorders (IDDs), exposure to excess iodine reportedly causes hypothyroidism, hyperthyroidism, and several other emerging deleterious impacts. The objective of the present study is to explore the influence of excess iodide exposure on carbohydrate and lipid metabolism along with the histoarchitecture of certain associated organs such as the pancreas, liver, kidney, and skeletal and cardiac muscle because information on those aspects was found to be scanty. Methods Twelve rats were taken, six were fed with iodine through gavage at a dose of 3.5 mg potassium iodide (KI)/100-g body weight, which corresponded to 500 times of the physiological daily dosage of iodide for a period of 60 days, while the other six formed the control group. Results KI-treated rats presented high body weight and urinary iodine with low TH levels, suggesting a primary thyroid dysfunction. There was an increase in blood glucose, cholesterol, triglycerides, low density lipoprotein (LDL), and very low density lipoprotein (VLDL), while high density lipoprotein (HDL) levels decreased. Tissue glycogen content in the liver and skeletal muscle was decreased and was increased in the heart and kidney. Histological sections of the pancreas showed a complete disruption with hardly recognizable histoarchistructure. Treated liver sections displayed the broadened central vein with degenerated hepatocytes, while skeletal muscle sections showed dissolution of muscle fibre cells linked with loss of glycogen from these organs. Histological changes in the heart include features similar to those of a fatty heart with cardiac muscles mutilation, while that of the kidney shows an increase in glomerular tuft size and Bowman's space expansion with general deterioration. Conclusions It may thus be concluded that excess iodine exposure for a long duration causes the development of a biochemical state of hypothyroidism. The developed hypothyroidism was found responsible for the hyperglycaemic and hypercholestromic status evident by high blood glucose and cholesterol levels and the depletion of glycogen at its storage sites in the liver and skeletal muscle but the extra deposition in the cardiac muscle and kidney; histomicrophotographs showed severe destruction of the pancreatic structure. All these alterations are conducive for the pathogenesis of cardiovascular and kidney diseases.
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Affiliation(s)
- Deotima Sarkar
- Endocrinology and Reproductive Physiology Laboratory, Department of Physiology, University of Calcutta, Kolkata-700 009, India
| | - Arijit Chakraborty
- Endocrinology and Reproductive Physiology Laboratory, Department of Physiology, University of Calcutta, Kolkata-700 009, India
| | - Adipa Saha
- Endocrinology and Reproductive Physiology Laboratory, Department of Physiology, University of Calcutta, Kolkata-700 009, India
| | - Amar K Chandra
- Endocrinology and Reproductive Physiology Laboratory, Department of Physiology, University of Calcutta, Kolkata-700 009, India
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Cui Y, Zhang Z, Zhang B, Zhao L, Hou C, Zeng Q, Nie J, Yu J, Zhao Y, Gao T, Wang A, Liu H. Excessive apoptosis and disordered autophagy flux contribute to the neurotoxicity induced by high iodine in Sprague-Dawley rat. Toxicol Lett 2018; 297:24-33. [DOI: 10.1016/j.toxlet.2018.08.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/22/2018] [Accepted: 08/28/2018] [Indexed: 12/20/2022]
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11
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Rong S, Gao Y, Yang Y, Shao H, Okekunle AP, Lv C, Du Y, Sun H, Jiang Y, Darko GM, Sun D. Nitric oxide is involved in the hypothyroidism with significant morphology changes in female Wistar rats induced by chronic exposure to high water iodine from potassium iodate. Chemosphere 2018; 206:320-329. [PMID: 29754056 DOI: 10.1016/j.chemosphere.2018.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/27/2018] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
Epidemiological studies indicated that chronic exposure to high water iodine is associated with primary hypothyroidism (PH) and subclinical hypothyroidism (SCH). However, the mechanism is not well understood. In this study, we explored whether chronic exposure to high water iodine from potassium iodate (KIO3) can induce hypothyroidism in addition to determining if nitric oxide (NO) is involved in the pathogenesis. 96 female Wistar rats were divided into six groups: control, I1000μg/L, I3000μg/L, I6000μg/L, N-nitro-L-arginine methylester (L-NAME) and L-NAME+I6000μg/L. After 3 months, urine iodine concentration, thyroid hormone, NO and nitric oxide synthase (NOS) serum levels were determined. Additionally, thyroid expression of inducible nitric oxide synthase (iNOS) was also investigated. Thyroid morphology was observed under light microscopy and transmission electron microscope. SCH as indicated by elevated serum thyrotropin (TSH) was induced among rats exposed to 3000 μg/L I-, while rats treated with 6000 μg/L I- presented PH characterized by elevated TSH and lowered total thyroxine in serum. Moreover, serum NO, NOS and iNOS expression in the thyroid were significantly increased in I3000μg/L and I6000μg/L groups. Changes in thyroid function and morphology in the L-NAME+I6000μg/L group were extenuated compared to I6000μg/L group. These findings suggested that chronic exposure to high water iodine from KIO3 likely induces hypothyroidism with significant morphology changes in female Wistar rats and NO appears to be involved in the pathogenesis.
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Affiliation(s)
- Shengzhong Rong
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Yanhui Gao
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Yanmei Yang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Hanwen Shao
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Akinkunmi Paul Okekunle
- Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin 150081, China
| | - Chunpeng Lv
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Yang Du
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Hongna Sun
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Yuting Jiang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Gottfried M Darko
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China
| | - Dianjun Sun
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin 150081, China.
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12
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Zhang B, Cui Y, Wang L, Zhao L, Hou C, Zeng Q, Zhang Z, Yu J, Zhao Y, Nie J, Chen X, Wang A, Liu H. Autophagy regulates high concentrations of iodide-induced apoptosis in SH-SY5Y cells. Toxicol Lett 2017; 284:129-135. [PMID: 29241733 DOI: 10.1016/j.toxlet.2017.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/07/2017] [Accepted: 12/09/2017] [Indexed: 01/23/2023]
Abstract
To date, there are many people residing in areas with high levels of iodide in water. Our previous epidemiological study showed that exposure to high iodine in drinking water significantly reduced the intelligence of children although the mechanisms remain unclear. To explore whether high concentrations of iodide may cause cytotoxic effect and the role of autophagy in the high iodide-induced apoptosis, human neuroblastoma cells (SH-SY5Y cells) were exposed to high concentrations of iodide. Morphological phenotypes, cell viability, Hoechst 33258 staining, the expression levels of apoptosis and autophagy-related proteins were detected. A possible effect of an inhibitor (3-methyladenine, 3-MA) or an inducer (rapamycin) of autophagy on high iodide-induced apoptosis also was examined. Results indicated that high iodide changed cellular morphology, decreased cell viability and increased the protein's expression level of apoptosis and autophagy. In addition, high iodide-induced apoptosis was enhanced by inhibition of autophagy and inhibited by activation of autophagy in SH-SY5Y cells. Collectively, high concentrations of iodide are toxic to SH-SY5Y cells, as well as induce apoptosis and autophagy. Furthermore, autophagy plays a regulatory role in high concentrations of iodide-induced apoptosis in SH-SY5Y cells.
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Affiliation(s)
- Bin Zhang
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, People's Republic of China
| | - Yushan Cui
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Lingzhi Wang
- Department of Quality Control, The First Affiliated Hospital of Zhejiang University, School of Medcine, Hangzhou, Zhejiang, People's Republic of China
| | - Liang Zhao
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Changchun Hou
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Qiang Zeng
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China
| | - Zushan Zhang
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, People's Republic of China
| | - Jingwen Yu
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, People's Republic of China
| | - Yang Zhao
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, People's Republic of China
| | - Junyan Nie
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, People's Republic of China
| | - Xuemin Chen
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Hubei, Wuhan 430030, People's Republic of China
| | - Aiguo Wang
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Hubei, Wuhan 430030, People's Republic of China.
| | - Hongliang Liu
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, People's Republic of China; Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, People's Republic of China; Tianjin Municipal Inspection Bureau for Health And Family Planning, 94 Guizhou Road, Heping District, Tianjin 300070, People's Republic of China.
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13
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Choi YS, Ock S, Kwon S, Jung SB, Seok KH, Kim YJ, Kim BK, Jeong JY. Excessive Iodine Status among School-Age Children in Korea: A First Report. Endocrinol Metab (Seoul) 2017; 32:370-374. [PMID: 28956367 PMCID: PMC5620034 DOI: 10.3803/enm.2017.32.3.370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 05/25/2017] [Accepted: 06/28/2017] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Korea is considered an iodine sufficient country, and several studies have been conducted regarding iodine status in healthy Korean adults, pregnant women, and preschool children. However, data on iodine status in Korean school-age children are lacking. Therefore, the iodine nutrition status of Korean school-age children was investigated by measuring urine iodine concentration (UIC). METHODS This cross-sectional study conducted between April and September 2016 comprised 373 school-age children. UIC was determined using a modified microplate method employing ammonium persulfate digestion followed by Sandell-Kolthoff reaction. RESULTS The median UIC was 458.2 μg/L. Excessive iodine intake (>300 μg/L) was found in 286 children (76.7%), with extremely high values exceeding 1,000 μg/L in 19.6% of subjects. Insufficient iodine intake (<100 μg/L) was observed in eight children (2.1%). UIC values were not significantly different between sexes. CONCLUSION Korean school-age children showed excessive iodine intake. Therefore, education regarding adequate iodine intake in school-age children is needed.
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Affiliation(s)
- Young Sik Choi
- Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea
| | - Soyoung Ock
- Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea
| | - Sukyoung Kwon
- Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea
| | - Sang Bong Jung
- Department Clinical Laboratory Science, Dong-Eui Institute of Technology, Busan, Korea
| | - Kwang Hyuk Seok
- Department of Biochemistry, Kosin University College of Medicine, Busan, Korea
- Cancer Research Institute, Kosin University College of Medicine, Busan, Korea
| | - Young Jin Kim
- Department of Biochemistry, Kosin University College of Medicine, Busan, Korea
- Cancer Research Institute, Kosin University College of Medicine, Busan, Korea
| | - Bu Kyung Kim
- Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea.
| | - Jee Yeong Jeong
- Department of Biochemistry, Kosin University College of Medicine, Busan, Korea
- Cancer Research Institute, Kosin University College of Medicine, Busan, Korea.
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Pichel N, Vivar M. A critical review on iodine presence in drinking water access at the Saharawi refugee camps (Tindouf, Algeria). J Trace Elem Med Biol 2017; 42:32-38. [PMID: 28595789 DOI: 10.1016/j.jtemb.2017.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/09/2017] [Accepted: 03/21/2017] [Indexed: 11/25/2022]
Abstract
Iodine content in drinking water at the Saharawi refugee camps was analysed to assess the controversy in the origin of the prevalence of goitre among this population. A review on the iodine presence in drinking water reported in the literature was conducted, along with international standards and guidelines for iodine intake and iodine concentration in drinking water were also consulted. Chinese legislation was taken as the reference standard to evaluate the iodine concentration in water as adequate (10-150μg/L) or not (high iodine >150μg/L and iodine excess goitre >300μg/L). Water sampling was conducted in 2015 and 2016 at the Saharawi camps (El Aiun, Awserd, Smara, Boujador and Dakhla) and at the institutional capital of Rabouni. The water supply in the camps is organized in three zones: El Aiun and Awserd where each 'wilaya' receives treated water 20days and raw water another 20days; Smara, Rabouni and Boujador receiving treated water continuously and Dakhla receiving raw water continuously. Results show that Smara, Rabouni and Boujador have access to drinking water with adequate iodine levels, as it occurs in Dakhla where raw water meets the Chinese standard, however in El Aiun and Awserd all population should have access to treated water given the current quality of the raw water supply. External supplies of water and animal milk could be also contributing to the high iodine intake. In conclusion, the contribution of drinking water as the main source of iodine to the urinary iodine concentration (UIC) and goitre prevalence among the Saharawi refugee population is not clear. Further studies should be conducted to assess the iodine content among all the nutritional sources of the population with a detailed study on the daily intake of these foods and drinks, including UIC and goitre prevalence studies.
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Affiliation(s)
- N Pichel
- IMDEA Water Institute, Alcalá de Henares 28805, Spain.
| | - M Vivar
- IMDEA Water Institute, Alcalá de Henares 28805, Spain; Department of Electrical Engineering, Universidad de Cádiz, Cádiz 11519, Spain
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15
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Biban BG, Lichiardopol C. Iodine Deficiency, Still a Global Problem? Curr Health Sci J 2017; 43:103-11. [PMID: 30595864 DOI: 10.12865/CHSJ.43.02.01] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/16/2017] [Indexed: 11/18/2022]
Abstract
Iodine Deficiency Disorders are a major public health problem worldwide affecting all groups of people of which children and lactating women are the most vulnerable categories. At a global scale, aproximately 2 billion people suffer of iodine deficiency (ID) of which aproximately 50 million present with clinical manifestations. Assesing iodine levels through different methods has proven to have a key role when discussing treatment options. Screening programs, and early ID diagnostic is important for pregnant women’s follow-up, especially in known countries with iodine dificiency. Universal salt iodization programs have been proposed over the world, but unfortunately have covered about 71% of the world’s population. The aim of this article is to adress the current standings of iodine status and influence on general population with a general focus on newborns and pregnant women and to review the worldwide perspective on available prevention methods.
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16
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Chandra AK, Chakraborty A. Influence of iodine in excess on seminiferous tubular structure and epididymal sperm character in male rats. Environ Toxicol 2017; 32:1823-1835. [PMID: 28205391 DOI: 10.1002/tox.22405] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 01/16/2017] [Accepted: 01/25/2017] [Indexed: 06/06/2023]
Abstract
Excess iodine induced public health problems are now emerging in many iodine sufficient regions for indiscriminate intake of iodine through various iodized products. It has been reported that excess iodine can disrupt overall male reproductive physiology by generating oxidative stress in the testis. However, information on the possible effect of iodine in excess on spermatozoa found less. In the present investigation flow cytometric techniques and scanning electron microscopy (SEM) have been used to study the spermatozoal functional as well as structural status under the influence of excess iodine; generation of ROS in the spermatozoa as evident by DCFDA, altered acrosomal integrity as observed by fluorescence lectin staining method and depolarized mitochondrial membrane potential (ΔΨm ) noticed by JC-1 staining. Ultrastructure of seminiferous tubule after excess iodine exposure indicated severe deterioration of seminiferous tubular surface architecture. Significant increase in spermatozoal DNA fragmentation and apoptotic sperms were found by acridine orange and Annexin V, respectively, however the plasma membrane integrity/viability was decreased as evident by propidium iodide staining in various incremental doses and durations under iodine excess. The study reveals that excess iodine could cause apoptosis of spermatozoal cells by inducing ROS that ultimately affects male fertility potential.
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Affiliation(s)
- Amar K Chandra
- Endocrinology and Reproductive Physiology Laboratory, Department of Physiology, University College of Science and Technology, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata, West Bengal, 700 009, India
| | - Arijit Chakraborty
- Endocrinology and Reproductive Physiology Laboratory, Department of Physiology, University College of Science and Technology, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata, West Bengal, 700 009, India
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17
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Sun D, Codling K, Chang S, Zhang S, Shen H, Su X, Chen Z, Scherpbier RW, Yan J. Eliminating Iodine Deficiency in China: Achievements, Challenges and Global Implications. Nutrients 2017; 9:E361. [PMID: 28379180 PMCID: PMC5409700 DOI: 10.3390/nu9040361] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/13/2017] [Accepted: 03/15/2017] [Indexed: 11/30/2022] Open
Abstract
The prevention of iodine deficiency through salt iodization has been recognized as a global success story, and China stands at the forefront of this achievement with one of the most successful programs in the world. High level political commitment, national mandatory legislation, a state-managed edible salt industry and a complex and highly sophisticated surveillance system have facilitated the success of the program. Challenges have arisen however, including: (i) concern that adequate iodine status in pregnant women cannot be achieved without causing above adequate iodine intakes in children; (ii) declining iodine intake as a result of reductions in salt consumption and increased consumption of processed foods, which may not be made with iodized salt; (iii) the existence of areas with high iodine content in the water; and (iv) declines in household use of iodized salt due to concerns about excess iodine intake and thyroid disease. This article reviews the achievements and challenges of the Chinese Iodine Deficiency Disorders (IDD) Elimination Program and reflects on lessons learned and implications for other national salt iodization programs.
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Affiliation(s)
- Dianjun Sun
- Centre for Endemic Disease Control, China Chinese Centre for Disease Control and Prevention, Harbin Medical University, 157 Baojian Road, Harbin 150081, China.
| | - Karen Codling
- United Nations Children's Fund, 12 Sanlitun Lu, Beijing 100600, China.
- Iodine Global Network, P.O. Box 51030, 375 des Epinettes, Ottawa, ON K1E 3E6, Canada.
| | - Suying Chang
- United Nations Children's Fund, 12 Sanlitun Lu, Beijing 100600, China.
| | - Shubin Zhang
- Parasitic and Endemic Disease Prevention and Control Division of the National Health and Family Planning Commission of China, 14 Zhichun Road, Beijing 100088, China.
| | - Hongmei Shen
- Centre for Endemic Disease Control, China Chinese Centre for Disease Control and Prevention, Harbin Medical University, 157 Baojian Road, Harbin 150081, China.
| | - Xiaohui Su
- Centre for Endemic Disease Control, China Chinese Centre for Disease Control and Prevention, Harbin Medical University, 157 Baojian Road, Harbin 150081, China.
| | - Zupei Chen
- Iodine Global Network, P.O. Box 51030, 375 des Epinettes, Ottawa, ON K1E 3E6, Canada.
| | - Robert W Scherpbier
- Iodine Global Network, P.O. Box 51030, 375 des Epinettes, Ottawa, ON K1E 3E6, Canada.
| | - Jun Yan
- Parasitic and Endemic Disease Prevention and Control Division of the National Health and Family Planning Commission of China, 14 Zhichun Road, Beijing 100088, China.
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Katagiri R, Yuan X, Kobayashi S, Sasaki S. Effect of excess iodine intake on thyroid diseases in different populations: A systematic review and meta-analyses including observational studies. PLoS One 2017; 12:e0173722. [PMID: 28282437 PMCID: PMC5345857 DOI: 10.1371/journal.pone.0173722] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 02/24/2017] [Indexed: 11/26/2022] Open
Abstract
Background Although several reports concerning the association of iodine excess and thyroid disease have appeared, no systematic review of the association between iodine excess intake and thyroid diseases, especially hyperthyroidism and hypothyroidism, has yet been reported. Method We conducted a systematic search of Ovid MEDLINE, PubMed, Cochrane Central Register of Controlled Trials databases, Ichushi-Web and CiNii database for intervention trials and observational studies. Search terms were constructed from related words for excess AND iodine intake or excretion AND thyroid hormones or diseases AND study designs. After considering the qualitative heterogeneity among studies, a meta-analysis was conducted and odds ratios and 95% confidence intervals (CI) were estimated in random-effects models. A protocol was registered with PROSPERO (No. CRD42015028081). Results 50 articles were included, including three intervention trials, six case-control studies, six follow-up studies and 35 cross-sectional studies. Three cross-sectional studies in adults included in meta-analysis. Odds ratio of overt and subclinical hypothyroidism between excess and adequate populations were 2.78 (CI:1.47 to 5.27) and 2.03 (CI:1.58 to 2.62) in adults, respectively. Source of excess iodine status was mainly iodized salt or water in included studies. Conclusion Although universal salt iodization has improved goiter rates, chronic exposure to excess iodine from water or poorly monitored salt are risk factors for hypothyroidism in free-living populations. Monitoring of both iodine concentration in salt as well as the iodine concentration in local drinking water are essential to preventing thyroid diseases. Hypothyroidism should be also carefully monitored in areas with excess iodine. Because of the low quality and limited number of included studies, further evidence and review are required.
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Affiliation(s)
- Ryoko Katagiri
- Department of Social and Preventive Epidemiology, Graduate School of Medicine, the University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Xiaoyi Yuan
- Department of Social and Preventive Epidemiology, School of Public Health, the University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Satomi Kobayashi
- Department of Social and Preventive Epidemiology, School of Public Health, the University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Satoshi Sasaki
- Department of Social and Preventive Epidemiology, Graduate School of Medicine, the University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Department of Social and Preventive Epidemiology, School of Public Health, the University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
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Chen W, Li X, Wu Y, Bian J, Shen J, Jiang W, Tan L, Wang X, Wang W, Pearce EN, Zimmermann MB, Carriquiry AL, Zhang W. Associations between iodine intake, thyroid volume, and goiter rate in school-aged Chinese children from areas with high iodine drinking water concentrations. Am J Clin Nutr 2017; 105:228-233. [PMID: 27927635 DOI: 10.3945/ajcn.116.139725] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 11/02/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Excessive iodine intake may have adverse effects on the thyroid, particularly in children, but the safe upper iodine intake concentration in children is unclear. OBJECTIVE We assessed the adverse effects of high iodine intake from iodine-rich drinking water on thyroid size in children by examining associations between thyroid volume (Tvol), total goiter rate (TGR), and iodine intake. DESIGN In a multistage cross-sectional survey, we collected two 24-h urine samples on 2 nonconsecutive days and determined 24-h urinary iodine excretion, then calculated habitual daily iodine intake. Ultrasonographic Tvol was measured, and TGR was calculated based on international and Chinese reference ranges for Tvol in children. RESULTS This study included 2089 children from Shandong province, where the median (IQR) drinking water iodine concentration was 183 μg/L (69-406 μg/L). The median (IQR) 24-h urinary iodine concentrations for the 2 collections were 381 μg/L (203-649 μg/L) and 398 μg/L (202-687 μg/L), respectively. The median (IQR) habitual daily iodine intake of children was 298 μg/d (186-437 μg/d). Tvols were slightly higher in boys than in girls (P = 0.035). The overall TGR was 9.7% and did not differ by sex. The TGR was ∼5% for children aged 7-10 and 11-14 y at iodine intakes of 200-249 and 250-299 μg/d, respectively. With the use of logistic regression and 2-step linear regression, a nonlinear association was observed between Tvol, TGR, and iodine intake, with a threshold intake of 150 μg/d. CONCLUSIONS Tvol begins to increase in children when iodine intake is ≥150 μg/d, and the TGR exceeds 5% when daily iodine intake is ≥250 μg/d for children aged 7-10 y and ≥300 μg/d for children aged 11-14 y. Our findings suggest that 150-249 and 150-299 μg/d seem to be safe upper iodine intake ranges for children aged 7-10 and 11-14 y, respectively. This trial was registered at clinicaltrials.gov as NCT02915536.
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Affiliation(s)
- Wen Chen
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Xiang Li
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Yalan Wu
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Jianchao Bian
- Shandong Institute for Endemic Disease Control and Research, Jinan, China
| | - Jun Shen
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Wen Jiang
- Shandong Institute for Endemic Disease Control and Research, Jinan, China
| | - Long Tan
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Xiaoming Wang
- Shandong Institute for Endemic Disease Control and Research, Jinan, China
| | - Wei Wang
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA
| | - Michael B Zimmermann
- Human Nutrition Laboratory, Swiss Federal Institute of Technology (ETH), Zürich, Switzerland; and
| | | | - Wanqi Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China;
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Sebotsa M, Dannhauser A, Mollentze W, Oosthuizen G, Mahomed F, Jooste P. Knowledge, attitudes and practices regarding iodine among patients with hyperthyroidism in the Free State, South Africa. South African Journal of Clinical Nutrition 2016. [DOI: 10.1080/16070658.2009.11734212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Lv S, Xie L, Xu D, Wang Y, Jia L, Du Y. Effect of reducing iodine excess on children's goiter prevalence in areas with high iodine in drinking water. Endocrine 2016; 52:296-304. [PMID: 26403613 DOI: 10.1007/s12020-015-0742-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/12/2015] [Indexed: 10/23/2022]
Abstract
The purpose of the study was to evaluate the effect of removing iodized salt on children's goiter prevalence in high iodine area (HIA). A total of 452 and 459 children aged 8-10 years old were selected by simple random sampling method before and after removing iodized salt from their diet in three towns with median water iodine content of 150-300 µg/l in Hengshui city of Hebei province of China. Their goiter status was judged using the thyroid volume (Tvol) reference for body surface area recommended by the WHO. After removing iodized salt, children's overall median urinary iodine content (MUIC) decreased from 518 (IQR 347,735) µg/l to 416 µg/l (IQR 274,609). Children's MUIC across sex and age group decreased significantly. The overall goiter prevalence in the three towns significantly decreased from 32.96 % (149/452) to 6.54 % (30/459) (P < 0.001). The goiter prevalence in 8-, 9-, and 10-year-old children decreased, respectively, from 38.04 % (35/92), 30.57 % (59/193), and 32.93 % (55/167) to 6.10 % (10/164), 6.75 % (11/163), and 6.82 % (9/132). The goiter prevalence in boys and girls decreased from 34.01 % (83/244) and 31.73 % (66/208) to 6.19 % (14/225) and 6.87 % (16/234), respectively. The decreases in children's goiter prevalence across gender and age groups were all statistically significant. The present study revealed that children's goiter prevalence decreased significantly after removing iodized salt from their diet for about one and half years in the HIA in Hebei province.
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Affiliation(s)
- Shengmin Lv
- Hebei Province Center for Disease Prevention and Control, No. 97, Huai'an Donglu, Shijiazhuang, 050021, Hebei, China.
| | - Lijun Xie
- Hebei Province Center for Disease Prevention and Control, No. 97, Huai'an Donglu, Shijiazhuang, 050021, Hebei, China
| | - Dong Xu
- Hebei Province Center for Disease Prevention and Control, No. 97, Huai'an Donglu, Shijiazhuang, 050021, Hebei, China
| | - Yuchun Wang
- Hengshui Municipal Center for Disease Prevention and Control, Hengshui, China
| | - Lihui Jia
- Hebei Province Center for Disease Prevention and Control, No. 97, Huai'an Donglu, Shijiazhuang, 050021, Hebei, China
| | - Yonggui Du
- Hebei Province Center for Disease Prevention and Control, No. 97, Huai'an Donglu, Shijiazhuang, 050021, Hebei, China
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Wang P, Sun H, Shang L, Zhang Q, He Y, Chen Z, Zhou Y, Zhang J, Wang Q, Zhao J, Shen H. Low Goiter Rate Associated with Small Average Thyroid Volume in Schoolchildren after the Elimination of Iodine Deficiency Disorders. PLoS One 2015; 10:e0141552. [PMID: 26513146 PMCID: PMC4626397 DOI: 10.1371/journal.pone.0141552] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 10/09/2015] [Indexed: 12/02/2022] Open
Abstract
Background After the implementation of the universal salt iodization (USI) program in 1996, seven cross-sectional school-based surveys have been conducted to monitor iodine deficiency disorders (IDD) among children in eastern China. Objectives This study aimed to examine the correlation of total goiter rate (TGR) with average thyroid volume (Tvol) and urinary iodine concentration (UIC) in Jiangsu province after IDD elimination. Design Probability-proportional-to-size sampling was applied to select 1,200 children aged 8–10 years old in 30 clusters for each survey in 1995, 1997, 1999, 2001, 2002, 2005, 2009 and 2011. We measured Tvol using ultrasonography in 8,314 children and measured UIC (4,767 subjects) and salt iodine (10,184 samples) using methods recommended by the World Health Organization. Tvol was used to calculate TGR based on the reference criteria specified for sex and body surface area (BSA). Results TGR decreased from 55.2% in 1997 to 1.0% in 2009, and geometric means of Tvol decreased from 3.63 mL to 1.33 mL, along with the UIC increasing from 83 μg/L in 1995 to 407 μg/L in 1999, then decreasing to 243 μg/L in 2005, and then increasing to 345 μg/L in 2011. In the low goiter population (TGR < 3.9%), TGR was positively associated with average Tvol (r = 0.99); UIC showed a non-linear association with average Tvol, and UIC > 300 μg/L was associated with a smaller average Tvol in children. Conclusions After IDD elimination in Jiangsu province in 2001, lower TGR was associated with smaller average Tvol. Average Tvol was more sensitive than TGR in detecting the fluctuation of UIC. A UIC of 300 μg/L may be defined as a critical value for population level iodine status monitoring.
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Affiliation(s)
- Peihua Wang
- Department of Epidemiology and Statistics, School of Public Health, Nanjing Medical University, Nanjing, China
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Hong Sun
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Li Shang
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Qinglan Zhang
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Yingxia He
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Zhigao Chen
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Yonglin Zhou
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Jingjing Zhang
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Qingqing Wang
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Jinkou Zhao
- Department of Environmental and Endemic Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Hongbing Shen
- Department of Epidemiology and Statistics, School of Public Health, Nanjing Medical University, Nanjing, China
- * E-mail:
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Tan L, Sang Z, Shen J, Liu H, Chen W, Zhao N, Wei W, Zhang G, Zhang W. Prevalence of thyroid dysfunction with adequate and excessive iodine intake in Hebei Province, People's Republic of China. Public Health Nutr 2015; 18:1692-7. [PMID: 25373938 DOI: 10.1017/S1368980014002237] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To explore (i) the prevalence of thyroid dysfunction in populations with adequate and excessive iodine intakes and (ii) the effect of iodine exposure on the prevalence of thyroid dysfunction. DESIGN Cross-sectional study was conducted in Hebei in 2010. The population was classified as having adequate or excessive iodine intake according to the iodine concentration in drinking water. Demographic information was collected by questionnaire. Levels of serum thyroid hormones, thyroid autoantibodies and iodine in drinking water and urine were measured. SETTING Villages with adequate or excessive drinking water iodine in Hebei Province, People's Republic of China. SUBJECTS A total of 854 men and women aged 20-50 years who had lived in the surveyed areas for over 5 years, including 348 from the adequate iodine area (AIA) and 506 from the excessive iodine area (EIA). RESULTS Median urinary iodine concentration was 185 μg/l in AIA and 1152 μg/l in EIA. The prevalence of thyroid dysfunction in AIA was 10.3%, which included 1.1% with hypothyroidism and 8.1% with subclinical hypothyroidism; and 20.6% in EIA, which included 3.6% with hypothyroidism and 13.6% with subclinical hypothyroidism. The positive rates of thyroglobulin antibody were 16.1% in AIA and 11.9% in EIA; the positive rates of thyroperoxidase antibody were 20.7% in AIA and 16.4% in EIA. CONCLUSIONS Excessive iodine intake may lead to increased prevalence of biochemical thyroid dysfunction, especially biochemical hypothyroidism. This is not related to an increase in prevalence of thyroid antibodies. Women are more susceptible to iodine excess.
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Lv S, Xu D, Wang Y, Jun Z, Jia L, Du Y. Impact of removing iodised salt on children's goitre status in areas with excessive iodine in drinking-water. Br J Nutr 2015; 113:114-9. [PMID: 25366513 DOI: 10.1017/S0007114514003365] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The impact of removing iodised salt on children's goitre status in a high-iodine area (HIA) remains unclear. The aim of the present study was to explore the changes in the prevalence of goitre in children after removing iodised salt from their diet. For this purpose, three towns with the median water iodine content of 150-300 μg/l were selected randomly in Hengshui City, Hebei Province, China. A total of 452 and 459 children were randomly selected from the three towns in order to measure thyroid volume by ultrasound before and after removing iodised salt, respectively. Their goitre status was judged using the criteria of age-specific thyroid volume recommended by the WHO. After removing iodised salt, the overall median urinary iodine content (MUIC) of children decreased from 518 (interquartile range (IQR) 347-735) to 416 (IQR 274-609) μg/l. The MUIC of children across sex and age group decreased significantly except for the age group of 9 years. The overall prevalence of goitre in the three towns significantly decreased from 24·56% (n 111/452) to 5·88% (n 27/459) (P< 0·001). Goitre prevalence in children aged 8-10 years decreased from 33·70% (n 31/92), 23·32% (n 45/193) and 20·96% (n 35/167) to 6·10% (n 10/164), 5·52% (n 9/163) and 6·06% (n 8/132), respectively. Goitre prevalence in boys and girls decreased from 27·05% (n 66/244) and 21·63% (n 45/208) to 6·66% (n 15/226) and 5·15% (n 12/233), respectively. The decreases in the prevalence of goitre in children across sex and age group were all statistically significant. The present study revealed that goitre prevalence in children decreased significantly after removing iodised salt from their diet for about 1·5 years in the HIA in Hebei Province.
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Zhao W, Han C, Shi X, Xiong C, Sun J, Shan Z, Teng W. Prevalence of goiter and thyroid nodules before and after implementation of the universal salt iodization program in mainland China from 1985 to 2014: a systematic review and meta-analysis. PLoS One 2014; 9:e109549. [PMID: 25313993 PMCID: PMC4196906 DOI: 10.1371/journal.pone.0109549] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 09/01/2014] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES We comprehensively estimated the prevalence of goiter and thyroid nodules (TNs) before and after the implementation of the Universal Salt Iodization (USI) program in mainland China and provided information for creating effective health policies. METHODS PubMed, Google Scholar, CNKI, Chinese Wanfang and Chongqing VIP databases were searched for relevant studies from Jan 1985 to Feb 2014. Data from eligible citations were extracted by two independent reviewers. All analyses were performed with Stata 11.0 and SPSS 17.0. RESULTS Eligible articles (N = 31; 4 in English and 27 in Chinese) included 52 studies (15 about goiter rates made before 1996 and 14 afterwards, and 23 about TNs). Our meta-analysis suggests a pooled prevalence for goiter before and after 1996 and for TNs of 22.8% (95% CI: 15.3%, 30.3%), 12.6% (95% CI: 9.4%, 15.8%) and 22.7% (95% CI: 18.3%, 27.0%), respectively. Egger's test of three independent categories revealed no evidence of publication bias (p = 0.101, 0.148 and 0.113, respectively). CONCLUSIONS The prevalence of goiter was reduced by almost half after 1996 in mainland China, so the USI program was considered beneficial. However, subgroup analysis suggests that both insufficient and excess iodine may be associated with goiter. The prevalence of goiter and TNs increased significantly after 2002, suggesting a risk of excessive iodine intake. Thus, salt iodization standardizations should be set according to local conditions.
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Affiliation(s)
- Wei Zhao
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Cheng Han
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Xiaoguang Shi
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Chuhui Xiong
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Jie Sun
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Zhongyan Shan
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Weiping Teng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, People's Republic of China
- * E-mail:
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Rydbeck F, Bottai M, Tofail F, Persson LÅ, Kippler M. Urinary iodine concentrations of pregnant women in rural Bangladesh: a longitudinal study. J Expo Sci Environ Epidemiol 2014; 24:504-509. [PMID: 24220214 PMCID: PMC4141302 DOI: 10.1038/jes.2013.79] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 10/02/2013] [Indexed: 06/01/2023]
Abstract
Iodine is an essential dietary element required for normal fetal growth and development. We aimed to explore intraindividual and interindividual variations in iodine intake in pregnant women and whether non-dietary factors might influence the intake. Iodine intake was assessed in 271 women, residing in Matlab, rural Bangladesh, by measuring their urinary iodine concentration (UIC) at gestational week (GW) 8, 14, 19, and 30 with inductively coupled plasma mass spectrometry. The women's UIC increased significantly during pregnancy (median 241 (GW8) and 300 μg/l (GW30)). About 6% of the women had insufficient iodine intake (UIC<150 μg/l) and 10% had excessive iodine intake (UIC≥500 μg/l) at all of their four sampling occasions. The women's UIC were dependent on their education, socio-economic status, and BMI, as well as the season of sampling and iodine concentrations in drinking water. Supplementation with a multi-micronutrient capsule, including 150 μg potassium iodine, increased the UIC in women with the lowest UIC (10th percentile) at GW30 but decreased the UIC in women with the highest UIC (90th percentile) at GW30. In conclusion, median UIC throughout pregnancy indicated adequate intake of iodine among pregnant women in Matlab, but, notably, consistently insufficient and excessive intake was also prevalent.
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Affiliation(s)
- Filip Rydbeck
- Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Matteo Bottai
- Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Fahmida Tofail
- International Centre for Diarrhoeal Disease Research, Mahakhali, Dhaka, Bangladesh
| | - Lars-Åke Persson
- Women's and Children's Health, International Maternal and Child Health, University Hospital, Uppsala, Sweden
| | - Maria Kippler
- Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
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Gao J, Zhang Z, Hu Y, Bian J, Jiang W, Wang X, Sun L, Jiang Q. Geographical distribution patterns of iodine in drinking-water and its associations with geological factors in Shandong Province, China. Int J Environ Res Public Health 2014; 11:5431-44. [PMID: 24852390 DOI: 10.3390/ijerph110505431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/29/2014] [Accepted: 05/04/2014] [Indexed: 11/17/2022]
Abstract
County-based spatial distribution characteristics and the related geological factors for iodine in drinking-water were studied in Shandong Province (China). Spatial autocorrelation analysis and spatial scan statistic were applied to analyze the spatial characteristics. Generalized linear models (GLMs) and geographically weighted regression (GWR) studies were conducted to explore the relationship between water iodine level and its related geological factors. The spatial distribution of iodine in drinking-water was significantly heterogeneous in Shandong Province (Moran's I = 0.52, Z = 7.4, p < 0.001). Two clusters for high iodine in drinking-water were identified in the south-western and north-western parts of Shandong Province by the purely spatial scan statistic approach. Both GLMs and GWR indicated a significantly global association between iodine in drinking-water and geological factors. Furthermore, GWR showed obviously spatial variability across the study region. Soil type and distance to Yellow River were statistically significant at most areas of Shandong Province, confirming the hypothesis that the Yellow River causes iodine deposits in Shandong Province. Our results suggested that the more effective regional monitoring plan and water improvement strategies should be strengthened targeting at the cluster areas based on the characteristics of geological factors and the spatial variability of local relationships between iodine in drinking-water and geological factors.
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Kassim IAR, Moloney G, Busili A, Nur AY, Paron P, Jooste P, Gadain H, Seal AJ. Iodine intake in Somalia is excessive and associated with the source of household drinking water. J Nutr 2014; 144:375-81. [PMID: 24500936 PMCID: PMC3927550 DOI: 10.3945/jn.113.176693] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Few data on iodine status in Somalia are available, but it is assumed that deficiency is a public health problem due to the limited access to iodized salt. We aimed to describe the iodine status of the population of Somalia and to investigate possible determinants of iodine status. A national 2-stage, stratified household cluster survey was conducted in 2009 in the Northwest, Northeast, and South Central Zones of Somalia. Urinary iodine concentration (UIC) was determined in samples from women (aged 15-45 y) and children (aged 6-11 y), and examination for visible goiter was performed in the Northwest and South Central strata. A 24-h household food-frequency questionnaire was conducted, and salt samples were tested for iodization. The median UICs for nonpregnant women and children were 329 and 416 μg/L, respectively, indicating excessive iodine intake (>300 μg/L). The prevalence of visible goiter was <4%. The coverage of salt iodization was low, with a national average of 7.7% (95% CI: 3.2%, 17.4%). Spatial analysis revealed localized areas of relatively high and low iodine status. Variations could not be explained by food consumption or salt iodization but were associated with the main source of household drinking water, with consumers of borehole water having a higher UIC (569 vs. 385 μg/L; P < 0.001). Iodine intake in Somalia is among the highest in the world and excessive according to WHO criteria. Further work is required to investigate the geochemistry and safety of groundwater sources in Somalia and the impact on human nutrition and health.
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Affiliation(s)
| | - Grainne Moloney
- United Nations (UN) Food and Agriculture Organization, Food Security and Nutrition Analysis Unit, Nairobi, Kenya
| | - Ahono Busili
- United Nations (UN) Food and Agriculture Organization, Food Security and Nutrition Analysis Unit, Nairobi, Kenya
| | - Abukar Yusuf Nur
- United Nations (UN) Food and Agriculture Organization, Food Security and Nutrition Analysis Unit, Nairobi, Kenya
| | - Paolo Paron
- UN Educational, Scientific and Cultural Organization (UNESCO) IHE, Institute for Water Education, Delft, The Netherlands
| | - Pieter Jooste
- The International Council for Control of Iodine Deficiency Disorders Global Network, Cape Town, South Africa,Centre of Excellence for Nutrition, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; and
| | - Hussein Gadain
- UN Food and Agriculture Organization, Somalia Water and Land Information Management, Nairobi, Kenya
| | - Andrew J. Seal
- Institute for Global Health, University College London, London, UK,To whom correspondence should be addressed. E-mail:
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Gao J, Lin X, Liu X, Yang Q, Zhang Z, Jiang Q, Bian J. Effect of combined excess iodine and low-protein diet on thyroid hormones and ultrastructure in Wistar rats. Biol Trace Elem Res 2013; 155:416-22. [PMID: 24037684 DOI: 10.1007/s12011-013-9811-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 08/29/2013] [Indexed: 12/26/2022]
Abstract
The aim of the present study was to illustrate the combined effect of excess iodine and low-protein diet on the thyroid, and the potential molecular mechanism of this effect. One hundred ninety-two Wistar rats were randomly divided into the following groups: normal; 10- (10HI), 50- (50HI), or 100-fold excess iodine (100HI); low-protein; and low-protein combined with 10- (L10HI), 50- (L50HI), or 100-fold excess iodine (L100HI). At the end of 2, 4, or 6 months, the rats were sacrificed for iodine concentration and thyroid hormone analyses. The histological appearance of the thyroid gland was observed at the end of 6 months. At the end of 6 months, the serum total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), and free triiodothyronine (FT3) levels in the 100HI, L10HI, L50HI, and L100HI groups were significantly lower than the control group (P < 0.05 or P < 0.01). Serum TT4, FT4, TT3, and FT3 levels in the low-protein excess iodine groups were significantly lower than the groups with an equal amount of excess iodine alone (P < 0.05 or P < 0.01). Light and electron microscopy showed that excess iodine caused damage to the ultrastructure of thyroid and apoptosis of follicular epithelial cells. In the 100HI, L50HI, and L100HI groups, thyroid follicular epithelial cells became flattened, and follicles became distended with colloid. The damage was more serious in low-protein groups. The present findings demonstrated that the low-protein diet aggravated the damage to the thyroid caused by excess iodine alone.
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Affiliation(s)
- Jie Gao
- Shandong Institute of Prevention and Control for Endemic Disease, No.11 Yandong Road, Lixia District, Jinan, 250014, China
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Sang Z, Chen W, Shen J, Tan L, Zhao N, Liu H, Wen S, Wei W, Zhang G, Zhang W. Long-term exposure to excessive iodine from water is associated with thyroid dysfunction in children. J Nutr 2013; 143:2038-43. [PMID: 24108132 DOI: 10.3945/jn.113.179135] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Previous studies have indicated an association between iodine excess and increased incidence of thyroid dysfunction in adults. However, there have been few studies on how the intake of excessive iodine affects thyroid function in children. The objective of this study was to assess the effects of a long-term exposure to excessive iodine on thyroid dysfunction in children. Urinary iodine concentration (UIC) and thyroid function in 371 children from a high iodine (HI) area (water iodine: 150-963 μg/L) and 150 children from an adequate iodine (AI) area (water iodine: 12.8-50.9 μg/L) were measured. The water iodine concentration in the HI area was higher than that in the AI area (P < 0.001) and the median urinary iodine concentration of children in the HI area was 1030 μg/L, which was 8.6 times that of children in the AI area (123 μg/L) (P < 0.001). Children in the HI area had a higher concentration of sensitive thyroid stimulating hormone and higher positivity of both thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb). The prevalence of thyroid diseases was higher in HI area children than that in AI area children (P = 0.000), especially subclinical hypothyroidism (SCH; P = 0.004). A body mass index (BMI) of ≥ 22.3 kg/m(2) was associated with the incidence of SCH (OR: 5.51; 95% CI: 1.52, 19.9; P = 0.009). UIC ≥ 600 μg/L (OR: 3.62; 95% CI: 1.22, 10.8; P = 0.024) and TPOAb or TGAb-positivity (Ab+ OR: 6.48; 95% CI: 1.78, 23.6; P = 0.005) in children were significantly and independently associated with SCH. Interactions between UIC ≥ 800 μg/L and Ab+ (P-interaction = 0.004) were found. Furthermore, increased thyroid volume was correlated with higher UIC (β = 0.22; P = 0.002). Excessive iodine intake in children in HI areas is associated with impaired thyroid function; UIC ≥ 600 μg/L and Ab+ are the risk factors for SCH. Effective measures need to be taken for reducing excessive iodine intake.
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Affiliation(s)
- Zhongna Sang
- Department of Nutrition and Food Science, and 4Department of Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China 5Centers for Disease Control and Prevention in Cangzhou City, Hebei Province, Cangzhou, China
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Huang W, Peng C, Huang H, Zhang J, Liu J, Mao L, Luo R, Xiao Y. Control of Iodine-Deficiency Disorders following Universal Salt Iodization in Shenzhen, China, 1997–2011. Food Nutr Bull 2013; 34:331-7. [DOI: 10.1177/156482651303400305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Since universal salt iodization (USI) was implemented in Shenzhen, China, in 1996, evaluation of the time trend of USI to indicate the control of iodine-deficiency disorders has not been performed. Objective To assess the time trend of median urinary iodine and total goiter rates from 1997 to 2011. Methods Probability-proportionate-to-size sampling was employed in the surveillance of iodine-deficiency disorders, for which schoolchildren aged 8 to 10 years were randomly selected from five districts of the city during each iodine-deficiency disorders survey. Urinary iodine content and thyroid size were measured by ammonium persulfate oxidation and B ultrasound, respectively. Results The coverage of iodized salt increased from 73.2% in 1997 to more than 90% in 2011. The median urinary iodine of children aged 8 to 10 years varied between 207.1 and 278.8 μg/L; these levels were above the urinary iodine level in 1995. The proportion of urine samples with iodine content above 300 μg/L was 45.6% in 1997 and decreased to 20.8% in 2011, indicating excessive consumption of iodine by the children. The goiter rate among children dropped from 10.8% in 1997 to 1.3% in 2011; both values were lower than the goiter rate in 1995, indicating that the spread of endemic goiter was under control. Conclusions Preliminary elimination of iodine-deficiency disorders was achieved by USI in Shenzhen. Nevertheless, some problems still existed, such as over-iodization. To clarify the causes of excessive urinary iodine content, the various sources of iodine from the diet need to be investigated in the future.
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Lv S, Wang Y, Xu D, Rutherford S, Chong Z, Du Y, Jia L, Zhao J. Drinking water contributes to excessive iodine intake among children in Hebei, China. Eur J Clin Nutr 2013; 67:961-5. [PMID: 23860000 DOI: 10.1038/ejcn.2013.127] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 11/08/2022]
Abstract
BACKGROUND/OBJECTIVES In Hebei province, China, over six million people are potentially exposed to excessive iodine through consumption of high iodine underground drinking water and consumption of iodized salt. The aim of this study is to evaluate the contributions of drinking water and iodized salt on children's iodine nutrition in one area of Hebei province in order to refine strategies to correct the excessive iodine intake in these areas. SUBJECTS/METHODS To investigate the relationships between iodine content in water, iodized salt and urinary iodine content (UIC) in children (8-10 years), we randomly sampled three towns with a known median water iodine (MWI) of 150-300 μg/l in Hengshui City, Hebei province and collected water, salt and urine samples. RESULTS The median UIC was 518.1 μg/l, the overall MWI was 247.0 μg/l, and 83% of children sampled were found to have urinary iodine concentrations higher than the WHO criterion of 300 μg/l. There was a significant and positive correlation between the median UIC of the children and the MWI in the 12 villages where the children lived (Spearman R=0.79, P=0.002), but the UIC was not significantly correlated with the median salt intake (MSI) (Spearman R=-0.17, P=0.6). A multiple linear regression analysis indicated that 68.7% of the variability in median UIC is associated with variability in MWI in the 12 villages. CONCLUSIONS Iodine in drinking water was identified to be the key contributor to this excessive iodine in children indicating that in these areas, intervention should focus on providing alternative drinking water supplies.
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Lv S, Xu D, Wang Y, Chong Z, Du Y, Jia L, Zhao J, Ma J. Goitre prevalence and epidemiological features in children living in areas with mildly excessive iodine in drinking-water. Br J Nutr 2014; 111:86-92. [PMID: 23768508 DOI: 10.1017/S0007114513001906] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The prevalence of goitre in areas with mildly excessive iodine in drinking-water is still under debate. The aim of the present study was to explore the prevalence of goitre and its epidemiological characteristics in these areas using WHO criteria. To this end, three towns with a median water iodine (MWI) of 150-300 μg/l were selected randomly in Hengshui City of Hebei Province of China, and one town with a MWI of 105 μg/l was chosen as a control. A total of 452 children in the three towns and 120 children in the control town were randomly selected to measure thyroid volume (T vol) by ultrasound. The goitre status of these children was judged using the criteria recommended by the WHO. The overall goitre prevalences in the three towns were 24·6 % (111/452) by age-specific T vol and 33·0 % (149/452) by body surface area (BSA)-adjusted T vol, which were significantly higher than that in the control town by both age-specific T vol (14·0 % (17/120), P= 0·015) and BSA-adjusted T vol (17·5 % (21/120), P= 0·001). Significant differences were found neither in goitre prevalences across sex by both age-specific T vol (P= 0·078) and BSA-adjusted T vol (P= 0·692) nor in that across age group by both BSA-adjusted T vol (P= 0·461) and age-specific T vol (P= 0·183). The present study found a high prevalence of goitre in children living in areas with mildly excessive iodine in drinking-water in Hebei Province. No significant differences were found in goitre prevalences across sex and age group. These results suggest that the T vol reference values recommended by the WHO could be too low for Chinese children.
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Alsanosy RMA, Gaffar AM, Khalafalla HEE, Mahfouz MS, Zaid ANS, Bani IA. Current iodine nutrition status and progress toward elimination of iodine deficiency disorders in Jazan, Saudi Arabia. BMC Public Health 2012; 12:1006. [PMID: 23167286 PMCID: PMC3533993 DOI: 10.1186/1471-2458-12-1006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Accepted: 11/13/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The term iodine deficiency disorders (IDD) refers to all the effects of iodine deficiency on growth and development in human and animal populations that can be prevented by correction of the iodine deficiency. The objective of this paper was to determine the iodine nutrition status among schoolchildren in the Jazan Region of the Kingdom of Saudi Arabia (KSA), by measuring urinary iodine concentrations and by clinical assessments of goiter rate. METHODS A school-based cross-sectional survey was conducted in the Jazan region of southwestern KSA from May to November 2010. A total of 311 children, aged 6-13 years, drawn from 12 schools, were selected by a three-stage cluster random sampling method. Data on sociodemographic characteristics were collected using a structured questionnaire. Urine samples were collected and physical examinations were conducted to determine the presence or absence of goiter. Data were analyzed using SPSS version 17.0. Chi square and independent t-tests were used for proportions and mean comparisons between groups. RESULTS Out of 360 selected children, 311 were examined. There were 131 males (42%) and 180 females (58%). The median urinary iodine concentration (UIC) of the study group was 421 μg/L. The study population proportion with UIC > 300 μg/L was 74% with a higher proportion among males and urban populations. The proportion of children with UIC of 100-300 μg/L was only 21% and was significantly higher among females compared with males (p < 0.001). Only about 3% of the children had a median UIC less than 50 μg/L. The prevalence of total goiter rate (TGR) among the sample of schoolchildren in Jazan was 11%, with significant variations between rural and urban populations and by gender. CONCLUSIONS The present study demonstrates a remarkable achievement in Universal Salt Iodization (USI) and IDD elimination goals in the Jazan area. However, UIC levels reflect excessive iodine intake and may put the population at risk of adverse health consequences like iodine-induced hyperthyroidism and autoimmune thyroid diseases.
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Affiliation(s)
- Rashad Mohammed Ali Alsanosy
- Family and Community Medicine Department, Faculty of Medicine, Jazan University, PO Box 2531, 45142, Jazan, Saudi Arabia
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Li WH, Dong BS, Li P, Li YF. Benefits and risks from the national strategy for improvement of iodine nutrition: A community-based epidemiologic survey in Chinese schoolchildren. Nutrition 2012; 28:1142-5. [DOI: 10.1016/j.nut.2012.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 04/10/2012] [Accepted: 04/10/2012] [Indexed: 10/28/2022]
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Han H, Xin P, Zhao L, Xu J, Xia Y, Yang X, Sun X, Hao L. Excess iodine and high-fat diet combination modulates lipid profile, thyroid hormone, and hepatic LDLr expression values in mice. Biol Trace Elem Res 2012; 147:233-9. [PMID: 22222482 DOI: 10.1007/s12011-011-9300-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 12/08/2011] [Indexed: 10/14/2022]
Abstract
The aim of this study was to illustrate the combined effect of excess iodine and high-fat diet on lipid metabolism and its potential molecular mechanism. Sixty Balb/c mice were randomly allocated to three control groups or three excess iodine groups and fed with a high-fat diet in the absence or presence of 1,200 μg/L iodine for 1, 3, or 6 months, respectively. Serum lipid parameters and serum thyroid hormones were measured. Expressions of scavenger receptor class B type-I (SR-BI) and low density lipoproteins receptor (LDLr) mRNA and protein in liver were detected. Thyroid histology and liver type 1 iodothyronine deiodinase activity were analyzed. At the end of 3 and 6 months, compared with control, serum TC, TG, and LDL-C in excess iodine group were significantly lower (p < 0.05). LDLr expression in liver was increased significantly (p < 0.05) and parallel to the change of serum TC and TG. TT3 and TT4 levels in serum were elevated and TSH decreased significantly (p < 0.05). Liver type I iodothyronine deiodinase activity was significantly higher (p < 0.05) than control at the end of 6 months. Moreover, a time course damage effect of excess iodine combined with high-fat diet on thyroid glands was observed. The present findings demonstrated that excess iodine combined with high-fat diet could cause damage to thyroid glands and lead to thyroid hormone disorder. Those in turn caused the upregulation of hepatic LDLr gene, which resulted in the disorder in serum lipids.
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Affiliation(s)
- Hao Han
- Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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Lv S, Zhao J, Xu D, Chong Z, Jia L, Du Y, Ma J, Rutherford S. An epidemiological survey of children's iodine nutrition and goitre status in regions with mildly excessive iodine in drinking water in Hebei Province, China. Public Health Nutr 2012; 15:1168-73. [DOI: 10.1017/s1368980012000146] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractObjectiveTo identify children's iodine nutrition and goitre status in areas with mildly excessive iodine in drinking water.DesignA cross-sectional survey. Probability proportional to size sampling was employed to randomly select children from thirty townships where the median iodine content in drinking water ranged from 150 to 300 μg/l; their urinary iodine concentrations were determined and their thyroid volumes were measured by ultrasound. Drinking water samples and salt samples from the villages where the children lived were collected using a systematic sampling method.SettingHebei Province of China.SubjectsA total of 1259 children aged 8–10 years (621 boys and 638 girls).ResultsChildren's median urinary iodine concentration was found to be 418·8 μg/l, and the iodine concentration was >300 μg/l for 68·3 % (248/363) of the urine samples. Children's median urinary iodine concentration in villages with median salt iodine >10 mg/kg was significantly higher than that in villages with median salt iodine <5 mg/kg (442·9 μg/l v. 305·4 μg/l, P ≈ 0). The goitre rate of 1259 children examined by ultrasound was 10·96 %.ConclusionsThe iodine intake of children living in areas with mildly excessive iodine in drinking water in Hebei Province was found to be excessive. The measured iodine excess in the sampled children is exacerbated by consumption of iodized salt. Goitre was identified in these areas; however, due to the limitation of the current criteria for children's thyroid volume, a comprehensive assessment of the prevalence of goitre in these regions could not be made and further study is required.
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Alves MLD, Duarte GC, Navarro AM, Tomimori EK. [Ultrasonographic evaluation of the thyroid, determination of ioduria and iodine concentration in kitchen salt used by schoolchildren in Ribeirão Preto, São Paulo, Brazil]. ACTA ACUST UNITED AC 2011; 54:813-8. [PMID: 21340174 DOI: 10.1590/s0004-27302010000900007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 11/03/2010] [Indexed: 11/22/2022]
Abstract
OBJECTIVE AND METHODS Previous studies have pointed out that Ribeirão Preto, São Paulo, is an area of borderline iodine deficiency, later becoming a region of excessive iodination. In a reevaluation of the iodine status of the city in 2007-2008, 300 schoolchildren aged 8 to 10 years were evaluated, from 3 schools of 3 different socioeconomic levels who were submitted to the determination of iodine concentration in urine samples and in kitchen salt and thyroid ultrasound. RESULTS AND CONCLUSION Among boys and girls ioduria was higher in the school of highest socioeconomic level compared to the others, with a significant difference in the ages 8 and 10 years for boys with ranges : p < 0,0001 and p = 0,0106, respectively; and in the ages 8 and 9 years for girls with ranges: p = 0,0024 and p = 0,0154, respectively. Median iodine concentrations in samples of kitchen salt ranged from 26.6 to 27.8 mg iodine/kg and did not differ between the schools studied. Ultrasound evaluation revealed that 15,6% of thyroids examined were hypoechoic, suggesting that these glands may present changes in the architecture not reflected yet in their volume.
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Affiliation(s)
- Maria Lúcia D'Arbo Alves
- Curso de Medicina, Faculdade de Medicina de Ribeirão Preto, Universidade de Ribeirão Preto, SP, Brasil.
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Xu J, Liu XL, Yang XF, Guo HL, Zhao LN, Sun XF. Supplemental selenium alleviates the toxic effects of excessive iodine on thyroid. Biol Trace Elem Res 2011; 141:110-8. [PMID: 20517655 DOI: 10.1007/s12011-010-8728-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 05/04/2010] [Indexed: 10/19/2022]
Abstract
As excessive iodine intake is associated with a decrease of the activities of selenocysteine-containing enzymes, supplemental selenium was hypothesized to alleviate the toxic effects of excessive iodine. In order to verify this hypothesis, Balb/C mice were tested by giving tap water with or without potassium iodate and/or sodium selenite for 16 weeks, and the levels of iodine in urine and thyroid, the hepatic selenium level, the activities of glutathione peroxidase (GSHPx), type 1 deiodinase (D1), and thyroid peroxidase (TPO) were assayed. It had been observed in excessive iodine group that hepatic selenium, the activities of GSHPx, D1, and TPO decreased, while in the groups of 0.2 mg/L, 0.3 mg/L and 0.4 mg/L supplemental selenium, the urinary iodine increased significantly. Compared with the group of excessive iodine intake alone, supplemental selenium groups had higher activities of GSHPx, D1, and TPO. We could draw the conclusion that supplemental selenium could alleviate toxic effect of excessive iodine on thyroid. The optimal dosage of selenium ranges from 0.2 to 0.3 mg/L which can protect against thyroid hormone dysfunction induced by excessive iodine intake.
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Affiliation(s)
- Jian Xu
- Shenzhen Center for Chronic Disease Control, Shenzhen, 518020, People's Republic of China.
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Shen H, Liu S, Sun D, Zhang S, Su X, Shen Y, Han H. Geographical distribution of drinking-water with high iodine level and association between high iodine level in drinking-water and goitre: a Chinese national investigation. Br J Nutr 2011; 106:243-7. [DOI: 10.1017/s0007114511000055] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Excessive iodine intake can cause thyroid function disorders as can be caused by iodine deficiency. There are many people residing in areas with high iodine levels in drinking-water in China. The main aim of the present study was to map the geographical distribution of drinking-water with high iodine level in China and to determine the relationship between high iodine level in drinking-water and goitre prevalence. Iodine in drinking-water was measured in 1978 towns of eleven provinces in China, with a total of 28 857 water samples. We randomly selected children of 8–10 years old, examined the presence of goitre and measured their urinary iodine in 299 towns of nine provinces. Of the 1978 towns studied, 488 had iodine levels between 150 and 300 μg/l in drinking-water, and in 246 towns, the iodine level was >300 μg/l. These towns are mainly distributed along the original Yellow River flood areas, the second largest river in China. Of the 56 751 children examined, goitre prevalence was 6·3 % in the areas with drinking-water iodine levels of 150–300 μg/l and 11·0 % in the areas with drinking-water iodine >300 μg/l. Goitre prevalence increased with water and urinary iodine levels. For children with urinary iodine >1500 μg/l, goitre prevalence was 3·69 times higher than that for those with urinary iodine levels of 100–199 μg/l. The present study suggests that drinking-water with high iodine levels is distributed in eleven provinces of China. Goitre becomes more prevalent with the increase in iodine level in drinking-water. Therefore, it becomes important to prevent goitre through stopping the provision of iodised salt and providing normal drinking-water iodine through pipelines in these areas in China.
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Zhao LN, Xu J, Peng XL, Tian LY, Hao LP, Yang XF, Ying CJ, Sun XF. Dose and time-dependent hypercholesterolemic effects of iodine excess via TRbeta1-mediated down regulation of hepatic LDLr gene expression. Eur J Nutr 2010; 49:257-65. [PMID: 19916081 DOI: 10.1007/s00394-009-0081-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 10/30/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND With the global improvement of iodine nutrition, iodine excess is emerging as a new concern. AIM OF STUDY The aim of this study is to illustrate the physiological effects and potential molecular mechanisms of excessive iodine intake on lipid metabolism. METHODS Balb/c mice were given drinking water containing different levels of iodine for 1 month and treated with 1.2 microg/mL iodine for different periods of time, respectively. Plasma lipid parameters and serum thyroid hormones were measured. Expressions of hepatic genes were detected by real-time polymerase chain reactions and Western blot. RESULTS Dose-dependent hypercholesterolemic effects were detected in mice (TC, r = 0.615; p < 0.01). Drinking 1.2 microg/mL iodine water for 1 month had no significant effect on serum lipid metabolism, while prolonged exposure induced an increase of serum cholesterol. Serum thyroid hormones were not affected by iodine throughout the study. At the molecular level, we detected a dose-dependent attenuation of hepatic low density lipoprotein receptor (LDLr) and thyroid hormone receptor beta1 (TRbeta1) expression in parallel to the change of serum cholesterol. Treatment with 1.2 microg/mL iodine water for 1 month did not affect LDLr and TRbeta1 expression, while 3 or 6 months exposure resulted in a decrease of their expression. CONCLUSION Present findings demonstrated dose- and time-dependent hypercholesterolemic effects of iodine excess. Furthermore, our data suggests that TRbeta1-mediated down regulation of hepatic LDLr gene may play a critical role in iodine excess-induced hypercholesterolemic effects.
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Liu HL, Lam LT, Zeng Q, Han SQ, Fu G, Hou CC. Effects of drinking water with high iodine concentration on the intelligence of children in Tianjin, China. J Public Health (Oxf) 2008; 31:32-8. [DOI: 10.1093/pubmed/fdn097] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Weng HX, Weng JK, Yan AL, Hong CL, Yong WB, Qin YC. Increment of iodine content in vegetable plants by applying iodized fertilizer and the residual characteristics of iodine in soil. Biol Trace Elem Res 2008; 123:218-28. [PMID: 18265951 DOI: 10.1007/s12011-008-8094-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Accepted: 01/22/2008] [Indexed: 11/27/2022]
Abstract
As a new attempt to control iodine deficiency disorder (IDD), we explored a method of iodine supplementation by raising the iodine content in vegetables. When grown in the soil supplemented with iodized fertilizer, the three experimental plant species (cucumber, aubergine, and radish) show increasing iodine levels in both leaf and fruit/rhizome tissues as the iodine content added in soil increases. Excessive iodine added to soil can be toxic to plants, whereas the tolerance limit to excessive iodine varies in the three plant species tested. The migration and volatilization of iodine in soil is correlated with the properties of the soil used. The residual iodine in soil increases as the iodine added to soil increases. The diatomite in the iodized fertilizer helps to increase the durability of the iodized fertilizer. This study potentially provides a safe and organic iodine supplementation method to control IDD.
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Affiliation(s)
- Huan-Xin Weng
- Institute of Environment & Biogeochemistry, Zhejiang University, Hangzhou, 310027, People's Republic of China.
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Executive Summary. South African Journal of Clinical Nutrition 2008; 21:253-271. [DOI: 10.1080/16070658.2008.11734565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Dayem M, Navarro V, Marsault R, Darcourt J, Lindenthal S, Pourcher T. From the molecular characterization of iodide transporters to the prevention of radioactive iodide exposure. Biochimie 2006; 88:1793-806. [PMID: 16905238 DOI: 10.1016/j.biochi.2006.07.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Accepted: 07/19/2006] [Indexed: 12/23/2022]
Abstract
In the event of a nuclear reactor accident, the major public health risk will likely result from the release and dispersion of volatile radio-iodines. Upon body exposure and food ingestion, these radio-iodines are concentrated in the thyroid, resulting in substantial thyroidal irradiation and accordingly causing thyroid cancers. Stable potassium iodide (KI) effectively blocks thyroid iodine uptake and is thus used in iodide prophylaxis for reactor accidents. The efficiency of KI is directly related to the physiological inhibition of the thyroid function in the presence of high plasma iodide concentrations. This regulation is called the Wolff-Chaikoff effect. However, to be fully effective, KI should be administered shortly before or immediately after radioiodine exposure. If KI is provided only several hours after exposure, it will elicit the opposite effect e.g. lead to an increase in the thyroid irradiation dose. To date, clear evaluation of the benefit and the potential toxicity of KI administration remain difficult, and additional data are needed. We outline in this review the molecular characterization of KI-induced regulation of the thyroid function. Significant advances in the knowledge of the iodide transport mechanisms and thyroid physiology have been made. Recently developed molecular tools should help clarify iodide metabolism and the Wolff-Chaikoff effect. The major goals are clarifying the factors which increase thyroid cancer risk after a reactor accident and improving the KI administration protocol. These will ultimately lead to the development of novel strategies to decrease thyroid irradiation after radio-iodine exposure.
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Affiliation(s)
- M Dayem
- Unité TIRO (Transporter in Imaging and Radiotherapy in Oncology), Commissariat à l'énergie atomique DSV-DIEP-SBTN, School of Medicine, University of Nice Sophia Antipolis, 28, avenue de Valombrose, 06107 Nice cedex, France
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Silva KDRR, Munasinghe DLL. Urinary iodine concentration of pregnant women and female adolescents as an indicator of excessive iodine intake in Sri Lanka. Food Nutr Bull 2006; 27:12-8. [PMID: 16572714 DOI: 10.1177/156482650602700102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Mild deficiencies and excesses of iodine have deleterious effects in both females and males. The iodine status of the population after implementation of the universal salt iodization program in Sri Lanka is not known. OBJECTIVE This cross-sectional study was carried out to assess the iodine status of pregnant women and female adolescents, with urinary iodine concentration used as the measure of outcome. METHODS The participants were 100 women in the first trimester of pregnancy and 99 female adolescents in Kuliyapitiya, Kurunegala District, North-Western Province, Sri Lanka. The urinary iodine concentration was measured in a casual urine sample from each subject. The iodate contents of salt samples collected from households of the adolescents participating in the study were also measured. RESULTS The median urinary iodine concentration of 185.0 microg/L and the prevalence of values under 50 microg/L of only 1% among the pregnant women indicate adequate iodine intake and optimal iodine nutrition. The median urinary iodine concentration (213.1 microg/L) among female adolescents indicates a more than adequate iodine intake and a risk of iodine-induced hyperthyroidism. Approximately 8% and 4% of the adolescents and pregnant women, respectively, had urinary iodine concentrations in the range of mild iodine deficiency (51 to 100 microg/L). More than half of the adolescents (56%) and 39% of the pregnant women had urinary iodine concentrations higher than optimal. The median iodine content in salt samples was 12.7 ppm. Only 20.2% of the samples were adequately iodized, and 10.1% of the samples had very high iodine levels. CONCLUSIONS Female adolescents and pregnant women had no iodine deficiency, but a considerable proportion of them, especially female adolescents, were at risk for iodine-induced hyperthyroidism. There is thus a need for proper monitoring of the salt iodization program to achieve acceptable iodine status.
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Affiliation(s)
- K D Renuka R Silva
- Department of Applied Nutrition, Faculty of Livestock, Fisheries and Nutrition, Wayamba University of Sri Lanka, Makandura, Gonawila 60170, Sri Lanka.
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Yang XF, Xu J, Hou XH, Guo HL, Hao LP, Yao P, Liu LG, Sun XF. Developmental toxic effects of chronic exposure to high doses of iodine in the mouse. Reprod Toxicol 2006; 22:725-30. [PMID: 16996244 DOI: 10.1016/j.reprotox.2006.05.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 04/03/2006] [Accepted: 05/24/2006] [Indexed: 10/24/2022]
Abstract
Chronic exposure to high doses of iodine induces thyroid dysfunction, but effects of chronic exposure to high amounts of iodine on pregnancy and fetal outcome are uncertain. In the present study, Balb/C mice were given different doses of iodine at the levels of 0 (sterile water), 1,500, 3,000, 6,000, 12,000 and 24,000 micro g/L in drinking water for 4 months, then were mated and the developmental toxicity and teratogenicity were evaluated. An obvious colloid goiter was observed, and serum total thyroxine (TT4) levels increased and serum total triiodothyronine (TT3) levels decreased significantly in dams when iodine dose reached 3,000 micro g/L. Maternal effect was evident by the reduction of average daily food consumption in higher doses of iodine groups. Embryotoxicity and teratogenicity were mainly indicated by the reduced body weight in female fetuses, the decreased number of live fetuses, and the increased incidence of resorptions, and especially skeletal variations. These results suggest that exposure to maternally toxic doses of iodine may have a potential developmental toxic effect.
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Affiliation(s)
- Xue F Yang
- Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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Duarte GC, Tomimori EK, Boriolli RA, Ferreira JE, Catarino RM, Camargo RYA, Medeiros-Neto G. Avaliação ultra-sonográfica da tireóide e determinação da iodúria em escolares de diferentes regiões do Estado de São Paulo. ACTA ACUST UNITED AC 2004; 48:842-8. [PMID: 15761558 DOI: 10.1590/s0004-27302004000600010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A iodação do sal é eficiente no combate às doenças decorrentes da deficiência de iodo, sendo empregada em todo território nacional desde 1995. O Estado de São Paulo é considerado uma área ioda-suficiente. Para avaliar a ingesta de iodo, foram selecionados aleatoriamente 844 escolares entre 6 e 14 anos, de seis regiões do Estado. Foram avaliados, sob o ponto de vista ecográfico da tireóide, 423 meninos e 421 meninas. Os volumes da glândula tireóide elevaram-se progressivamente com a idade, guardando correlação positiva e significativa com a superfície corporal. Cerca de 1,6% dos escolares apresentava bócio. Nódulos, cistos, hemiagenesia foram detectados em 1,4% dos examinados. Notamos excessiva excreção urinária de iodo nesta população, cerca de 53% eliminou acima de 300<FONT FACE=Symbol>µ</FONT>g Iodo/L e valores acima de 600<FONT FACE=Symbol>µ</FONT>gI/L foram encontrados em 21% dos escolares. As amostras de sal doméstico apresentavam valores entre 28,1 e 63,3mg Iodo/kg de sal. Concluímos que a população escolar do Estado de São Paulo apresenta excessiva ingestão diária de iodo, a qual, extrapolada para a população em geral, pode induzir várias alterações da função tireóidea, como hipertiroidismo subclínico (em idosos) e tireoidite crônica autoimune na população adulta, em geral.
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Affiliation(s)
- Glaucia C Duarte
- Unidade de Tireóide, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP
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Abstract
Thyroid diseases are common in all populations but the type and frequency depends on environmental factors. In Denmark geographical differences in iodine intake are caused by different iodine contents of drinking water, which varies from < 1 to 139 microg iodine per litre. Comparative epidemiologic studies have demonstrated considerable differences in type and occurrence of thyroid disease with more goitre and hyperthyroidism in Aalborg with water iodine content around 5 microg/L, and more hypothyroidism in Copenhagen with water iodine around 20 microg/L. In Denmark, iodine in ground water is bound in humic substances, which have probably leached from marine sediments in the aquifers. Interestingly, humic substances in water from other parts of the world have goitrogenic properties, especially humic substances from coal and shale. Humic substances are heterogeneous mixtures of naturally occurring molecules, produced by decomposition of plant and animal tissues. The effect of humic substances in drinking water on the epidemiology of thyroid disease probably depends on the source of aquifer sediments.
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Affiliation(s)
- Peter Laurberg
- Department of Endocrinology and Medicine, University Hospital Aalborg, Denmark.
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