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Fischer L, Andersson M, Braegger C, Herter-Aeberli I. Iodine intake in the Swiss population 100 years after the introduction of iodised salt: a cross-sectional national study in children and pregnant women. Eur J Nutr 2024; 63:573-587. [PMID: 38141138 PMCID: PMC10899291 DOI: 10.1007/s00394-023-03287-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023]
Abstract
PURPOSE The Swiss voluntary salt iodisation programme has successfully prevented iodine deficiency for 100 years, but dietary habits are changing and today only one-third of processed foods contain iodised salt. We aimed to monitor the current iodine status in children and pregnant women. METHODS We conducted a nationwide cross-sectional study in children (6-12 years) and pregnant women and measured the urinary iodine concentration (UIC) in spot urine samples. We estimated the iodine intake using UIC and urinary creatinine concentration (UCC) and determined the prevalence of intakes below the average requirement (AR) using the SPADE method. We measured dried blood spot (DBS) thyroglobulin (Tg), TSH and total T4 in pregnant women. RESULTS The median UIC was 127 μg/L (bootstrapped 95% CI 119, 140, n = 362) in children and 97 μg/L (bootstrapped 95% CI 90, 106, n = 473) in pregnant women. The estimated prevalence of inadequate iodine intake (< 65 μg/day) was 5.4% (bootstrapped 95% CI 0.0, 14.6) in children. Half (47%) of the women consumed iodine-containing multivitamin and mineral supplements (≥ 150 μg/day). Compared to non-users, users had higher median UIC (129 vs. 81 μg/L, P < 0.001), lower prevalence of inadequacy (< 160 μg/day; 0.2 vs. 31%) and lower DBS-Tg (23 vs. 29 μg/L, P < 0.001). All women were euthyroid. CONCLUSIONS The Swiss diet and current salt fortification provides adequate iodine intake in children, but not in all pregnant women. Iodine supplements cover the dietary gap in pregnancy but are not universally consumed. Therefore, improved use of iodised salt in processed foods is desired to ensure adequate iodine intake in all population groups. This trial was registered at clinicaltrials.gov as NCT04524013.
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Affiliation(s)
- Lena Fischer
- Nutrition Research Unit, Children's Research Centre, University Children's Hospital Zurich - Eleonore Foundation, Steinwiesstrasse 75, 8032, Zurich, Switzerland.
- Laboratory of Nutrition and Metabolic Epigenetics, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.
| | - Maria Andersson
- Nutrition Research Unit, Children's Research Centre, University Children's Hospital Zurich - Eleonore Foundation, Steinwiesstrasse 75, 8032, Zurich, Switzerland
| | - Christian Braegger
- Nutrition Research Unit, Children's Research Centre, University Children's Hospital Zurich - Eleonore Foundation, Steinwiesstrasse 75, 8032, Zurich, Switzerland
| | - Isabelle Herter-Aeberli
- Laboratory of Nutrition and Metabolic Epigenetics, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
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Berlińska A, Świątkowska-Stodulska R. Clinical use of thyroglobulin: not only thyroid cancer. Endocrine 2024:10.1007/s12020-023-03658-3. [PMID: 38182855 DOI: 10.1007/s12020-023-03658-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/10/2023] [Indexed: 01/07/2024]
Abstract
Thyroglobulin (TG) is a dimeric glycoprotein produced exclusively by mature thyroid tissue and stored within the follicular lumen. It is essential for the organification of iodine and the production of thyroid hormones. The concentration of TG in the bloodstream varies between individuals and depends on factors such as thyroid mass, stimulation of the gland by thyrotropin or autoantibodies, and tissue destruction. TG is essential to monitor patients with differentiated thyroid cancer; however, its use is not limited only to this clinical entity. Measurement of circulating TG can provide better insight into numerous clinical scenarios, such as destructive thyroiditis, presence of ectopic thyroid tissue, thyroid trauma, factitious thyrotoxicosis, or iodine nutrition. Lately, TG has found its new clinical use in immune checkpoint-related thyroid dysfunction. TG measurement should be performed carefully in patients with antithyroglobulin antibodies due to possible laboratory interferences. In this review, we offer a summary of current knowledge about the clinical use of TG and the implications it brings to daily practice.
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Affiliation(s)
- Agata Berlińska
- Department of Endocrinology and Internal Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland.
| | - Renata Świątkowska-Stodulska
- Department of Endocrinology and Internal Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
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Henjum S, Groufh-Jacobsen S, Aakre I, Gjengedal ELF, Langfjord MM, Heen E, Sele V, Andersson M. Thyroid function and urinary concentrations of iodine, selenium, and arsenic in vegans, lacto-ovo vegetarians and pescatarians. Eur J Nutr 2023; 62:3329-3338. [PMID: 37592132 PMCID: PMC10611878 DOI: 10.1007/s00394-023-03218-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 07/18/2023] [Indexed: 08/19/2023]
Abstract
PURPOSE Populations following a plant-based diet may be at particular risk of thyroid dysfunction due to low iodine and selenium intakes. The main purpose was to assess thyroid function and urinary concentration of iodine, selenium, and arsenic, in subjects following a vegan, lacto-ovo vegetarian, or pescatarian diet. METHODS In Norway, a country without mandatory dietary iodine fortification, 205 adults, following vegan (n = 115), lacto-ovo vegetarian (n = 55) and pescatarian diet (n = 35) were included. Thyroglobulin (Tg), thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and serum anti-TPO (S-anti-TPO) were measured in a venous blood sample and concentrations of iodine (UIC), creatinine (UCC), selenium, and arsenic were measured from single spot urine samples. RESULTS Subclinical hypothyroidism (TSH > 4.0 mU/L) was observed in 3% of subjects. The overall median (p25, p75) Tg was 17 (9, 30) µg/L and vegans had higher Tg compared to pescatarians. Vegans not consuming iodine-containing supplements (n = 43) had higher Tg, than supplement users (n = 72), 27 (11, 44) vs. 16 (8, 25) µg/L and higher fT4, 16 (15, 17) vs. 15 (14, 17) pmol/L, respectively. The overall median UIC was 57 (28, 130) µg/L, all dietary groups had median UIC below WHO thresholds. Median urinary selenium and arsenic concentration was 13 (6, 22) and 3 (2, 8) µg/L, respectively. CONCLUSION The prevalence of subclinical hypothyroidism was low and fT4 and fT3 were within the normal range for all dietary groups. Vegans had significantly increased Tg compared to pescatarians.
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Affiliation(s)
- Sigrun Henjum
- Department of Nursing and Health Promotion, Faculty of Health Sciences, Oslo Metropolitan University, Kunnskapsveien 55, 2007 Kjeller, 0130, Oslo, Norway.
| | - Synne Groufh-Jacobsen
- Department of Nutrition and Public Health, Faculty of Health and Sport Science, University of Agder, Universitetsveien 25, 4630, Kristiansand, Norway
| | - Inger Aakre
- Department of Marine Toxicology, Institute of Marine Research, 5817, Bergen, Norway
| | - Elin Lovise Folven Gjengedal
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Mina Marthinsen Langfjord
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Espen Heen
- Institute of Health and Society, Medical Faculty, University of Oslo, Oslo, Norway
| | - Veronika Sele
- Department of Marine Toxicology, Institute of Marine Research, 5817, Bergen, Norway
| | - Maria Andersson
- Nutrition Research Unit, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032, Zurich, Switzerland
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Groufh-Jacobsen S, Abel MH, Brantsæter AL, Andersson M, Meyer HE, Henjum S. National monitoring of iodine, sodium, and vitamin D status in toddlers and women of childbearing age - results and lessons learned from a pilot study in Norway. Food Nutr Res 2023; 67:9088. [PMID: 37691743 PMCID: PMC10492227 DOI: 10.29219/fnr.v67.9088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 06/12/2023] [Accepted: 07/05/2023] [Indexed: 09/12/2023] Open
Abstract
Background Norway is lacking a population-based national monitoring program for iodine, sodium, and vitamin D status. Objective The aim of this study was to pilot-test a study design for collecting biological samples from a country-representative sample of 2-year-old children and their mothers and to report results for iodine, salt, and vitamin D at baseline, before initiation of salt iodization in Norway. Design In a cross-sectional study, we recruited 2-year-old children and their mothers during the routine 2-year check-up through 38 randomly selected health clinics in 2021. Spot urine samples were analyzed for iodine, creatinine, and sodium, and dried blood spots from the mothers were analyzed for thyroglobulin (Tg) and 25-hydroxyvitamin D (25(OH)D). Results We aimed at including 400 mother-child pairs but recruited only 55 pairs. Major challenges were closed health clinics due to the COVID-19 pandemic, lack of motivation of the health personnel to prioritize recruiting, missing information about non-participation, and high workload for participants. The median urinary iodine concentration (UIC) was 123 (95% CI: 76, 228) µg/L in the toddlers and 83 (95% CI: 72, 99) µg/L in the mothers. The median urinary sodium concentration (UNaC) was 62 (95% CI: 37, 91) mmol/L in the toddlers and 93 (95% CI: 77, 107) mmol/L in the mothers. Of the mothers, 18% had levels of 25(OH)D <50 nmol/L (suboptimal status). Discussion and conclusion Lessons learned from the pilot study will be used to design a national monitoring program for toddlers and women of childbearing age in Norway. The results indicate that 2-year-old children and women of childbearing age in Norway may have inadequate iodine intakes at the group level, while for vitamin D, most of the mothers had adequate status.
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Affiliation(s)
- Synne Groufh-Jacobsen
- Department of Nutrition and Public Health, Faculty of Health and Sport Science, University of Agder, Kristiansand, Norway
| | - Marianne Hope Abel
- Department of Physical Health and Ageing, Norwegian Institute of Public Health, Oslo, Norway
| | - Anne Lise Brantsæter
- Department of Food Safety, Division of Climate and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Maria Andersson
- Nutrition Research Unit, University Children’s Hospital Zurich, Zurich, Switzerland
| | - Haakon E. Meyer
- Department of Physical Health and Ageing, Norwegian Institute of Public Health, Oslo, Norway
| | - Sigrun Henjum
- Department of Nursing and Health Promotion, Faculty of Health Science, Oslo Metropolitan University, Oslo, Norway
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The Impact of Iodine Concentration Disorders on Health and Cancer. Nutrients 2022; 14:nu14112209. [PMID: 35684009 PMCID: PMC9182735 DOI: 10.3390/nu14112209] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [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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Andersson M, Braegger CP. The Role of Iodine for Thyroid Function in Lactating Women and Infants. Endocr Rev 2022; 43:469-506. [PMID: 35552681 PMCID: PMC9113141 DOI: 10.1210/endrev/bnab029] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Indexed: 12/18/2022]
Abstract
Iodine is a micronutrient needed for the production of thyroid hormones, which regulate metabolism, growth, and development. Iodine deficiency or excess may alter the thyroid hormone synthesis. The potential effects on infant development depend on the degree, timing, and duration of exposure. The iodine requirement is particularly high during infancy because of elevated thyroid hormone turnover. Breastfed infants rely on iodine provided by human milk, but the iodine concentration in breast milk is determined by the maternal iodine intake. Diets in many countries cannot provide sufficient iodine, and deficiency is prevented by iodine fortification of salt. However, the coverage of iodized salt varies between countries. Epidemiological data suggest large differences in the iodine intake in lactating women, infants, and toddlers worldwide, ranging from deficient to excessive intake. In this review, we provide an overview of the current knowledge and recent advances in the understanding of iodine nutrition and its association with thyroid function in lactating women, infants, and toddlers. We discuss risk factors for iodine malnutrition and the impact of targeted intervention strategies on these vulnerable population groups. We highlight the importance of appropriate definitions of optimal iodine nutrition and the need for more data assessing the risk of mild iodine deficiency for thyroid disorders during the first 2 years in life.
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Affiliation(s)
- Maria Andersson
- Nutrition Research Unit, University Children's Hospital Zurich, CH-8032 Zürich, Switzerland
| | - Christian P Braegger
- Nutrition Research Unit, University Children's Hospital Zurich, CH-8032 Zürich, Switzerland
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Abstract
PURPOSE OF REVIEW Iodine deficiency is a global concern, and in recent years, there has been a significant improvement in the number of countries identified as being iodine-sufficient. This review considers the best strategies to ensure iodine sufficiency among breastfeeding women and their infants. RECENT FINDINGS Fortification strategies to improve iodine intake have been adequate for school-age children (SAC); however, often, iodine deficiency remains for breastfeeding women and their infants. Daily supplementation with iodine is not an ideal strategy to overcome deficiency. Countries defined as iodine-sufficient, but where pregnant and breastfeeding women have inadequate intake, should consider increasing salt iodine concentration, such that the median urinary iodine concentration of SAC can be up to 299 µg/L. This will ensure adequate intake for mothers and infants, without SAC being at risk thyroid dysfunction. Consensus is required for thresholds for iodine adequacy for breastfeeding women and infants.
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Avramovska M, Kostova NM, Karanfilski B, Hunziker S, Vaskova O, Dimitrov G, Dzikova E, Markova AD, Lega MH, Tofoski G, Sikole A. Thyroid Function of Pregnant Women and Perinatal Outcomes in North Macedonia. REVISTA BRASILEIRA DE GINECOLOGIA E OBSTETRÍCIA 2021; 43:736-742. [PMID: 34784629 PMCID: PMC10183913 DOI: 10.1055/s-0041-1736172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Thyroid diseases are the second most common endocrine disorders in the reproductive period of women. They can be associated with intrauterine growth restriction (IUGR), preterm delivery, low Apgar score, low birthweight (LBW) or fetal death. The aim of the present study is to explore thyroid dysfunction and its relationship with some poor perinatal outcomes (Apgar Score, low birthweight, and preterm delivery). METHODS Dried blood spot samples from 358 healthy pregnant women were analyzed for thyroid stimulating hormone (TSH), total thyroxine (TT4), and thyroglobulin (Tg). Neonatal data were collected upon delivery. Four groups were formed based on thyroid function tests (TFTs). RESULTS Of the 358 tested women, 218 (60.72%) were euthyroid. Isolated hypothyroxinemia was present in 132 women (36.76%), subclinical hyperthyroidism in 7 women (1.94%), and overt hypothyroidism in 1 (0.28%). The perinatal outcomes IUGR (p = 0.028) and Apgar score 1 minute (p = 0.015) were significantly different between thyroid function test [TFT]-distinct groups. In the multiple regression analysis, TT4 showed a statistically significant inverse predictive impact on LBW (p < 0.0001), but a positive impact of Tg on LBW (p = 0.0351). CONCLUSION Thyroid hormones alone do not have a direct impact on neonatal outcomes, but the percentage of their participation in the total process cannot be neglected. Based on the regression analysis, we can conclude that TT4 and Tg can be used as predictors of neonatal outcome, expressed through birthweight and Apgar score. The present study aims to contribute to determine whether a test for thyroid status should become routine screening during pregnancy.
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Affiliation(s)
- Maja Avramovska
- Department of Obstetrics and Gynecology, Clinical Hospital "Dr. Trifun Panovski" - Bitola, Partizanska nn, North Macedonia
| | - Neda Milevska Kostova
- Departement Gesundheitswissenschaften und Technologie, Institute for Social Innovation, Skopje, Skopje, North Macedonia
| | - Borislav Karanfilski
- National Committee for Iodine Deficiency, Ministry of Health, Skopje, North Macedonia
| | - Sandra Hunziker
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Olivija Vaskova
- Institute of Pathophysiology and Nuclear Medicine, Faculty of Medicine, Ss. Cyril and Methodius University Skopje, Skopje, North Macedonia
| | - Goran Dimitrov
- University Clinic of Gynecology and Obstetrics, Faculty of Medicine, Ss. Cyril and Methodius University Skopje, Skopje, North Macedonia
| | - Elena Dzikova
- University Clinic of Gynecology and Obstetrics, Faculty of Medicine, Ss. Cyril and Methodius University Skopje, Skopje, North Macedonia
| | - Ana Daneva Markova
- University Clinic of Gynecology and Obstetrics, Faculty of Medicine, Ss. Cyril and Methodius University Skopje, Skopje, North Macedonia
| | - Marija Hadzi Lega
- Department for Fetal Screening and Perinatal Medicine, Danat al Emarat Hospital for Women and Children, Abu Dhabi, Emirate of Abu Dhabi
| | - Gligor Tofoski
- University Clinic of Gynecology and Obstetrics, Faculty of Medicine, Ss. Cyril and Methodius University Skopje, Skopje, North Macedonia
| | - Aleksandar Sikole
- Department of Nephrology, University Clinic of Nephrology, Faculty of Medicine, Ss. Cyril and Methodius University Skopje, Skopje, North Macedonia
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Prpić M, Franceschi M, Vidranski V, Andersson M, Zimmermann MB, Hunziker S, Milošević M, Kusić Z, Jukić T. IODINE STATUS AND THYROID FUNCTION IN LACTATING WOMEN AND INFANTS - A SURVEY IN THE ZAGREB AREA, CROATIA. Acta Clin Croat 2021; 60:259-267. [PMID: 34744276 PMCID: PMC8564841 DOI: 10.20471/acc.2021.60.02.12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 09/24/2019] [Indexed: 11/24/2022] Open
Abstract
Lactating women (LW) and infants have high dietary iodine requirements and are at risk of iodine deficiency. The aim of the study was to assess iodine status and thyroid function in LW and their breastfed infants in Zagreb, Croatia. The study included 133 LW and breastfed infant pairs. Urinary iodine concentration (UIC) and thyroid function parameters were measured in all subjects. In LW, breast milk iodine concentration (BMIC) was measured and iodine and salt rich food frequency questionnaire data were collected. Results of analysis indicated that 99.2% of the LW used iodized salt in household and 20.4% used iodine-containing vitamin and mineral supplements. Median (IQR) UIC was 75 µg/L (19.0-180.5 µg/L) in LW and 234 µg/L (151.0-367.5 µg/L) in infants, whereas BMIC was 121 µg/kg (87.8-170.8 µg/kg). Multivariate regression analysis revealed BMIC to be a significant predictor of infant UIC (p<0.001). Positive correlation was recorded between LW and infant thyroid function. This was the first study in Croatia demonstrating BMIC to be a reliable biomarker of iodine status during lactation and predicting iodine intake in breastfed infants. The study confirmed that mandatory salt iodization in Croatia ensured sufficient dietary iodine for LW and optimal iodine intake for breastfed infants via breast milk.
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Affiliation(s)
| | - Maja Franceschi
- 1Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia; 2School of Medicine, University of Zagreb, Zagreb, Croatia; 3Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia; 4Division of Gastroenterology and Nutrition, Zurich University Children's Hospital, Zurich, Switzerland; 5Iodine Global Network, Ottawa, Ontario, Canada; 6Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Zurich ETH, Zurich, Switzerland; 7University of Zagreb, School of Medicine, Andrija Štampar School of Public Health, WHO Collaborative Centre for Occupational Health, Zagreb, Croatia; 8Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Valentina Vidranski
- 1Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia; 2School of Medicine, University of Zagreb, Zagreb, Croatia; 3Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia; 4Division of Gastroenterology and Nutrition, Zurich University Children's Hospital, Zurich, Switzerland; 5Iodine Global Network, Ottawa, Ontario, Canada; 6Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Zurich ETH, Zurich, Switzerland; 7University of Zagreb, School of Medicine, Andrija Štampar School of Public Health, WHO Collaborative Centre for Occupational Health, Zagreb, Croatia; 8Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Maria Andersson
- 1Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia; 2School of Medicine, University of Zagreb, Zagreb, Croatia; 3Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia; 4Division of Gastroenterology and Nutrition, Zurich University Children's Hospital, Zurich, Switzerland; 5Iodine Global Network, Ottawa, Ontario, Canada; 6Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Zurich ETH, Zurich, Switzerland; 7University of Zagreb, School of Medicine, Andrija Štampar School of Public Health, WHO Collaborative Centre for Occupational Health, Zagreb, Croatia; 8Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Michael B Zimmermann
- 1Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia; 2School of Medicine, University of Zagreb, Zagreb, Croatia; 3Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia; 4Division of Gastroenterology and Nutrition, Zurich University Children's Hospital, Zurich, Switzerland; 5Iodine Global Network, Ottawa, Ontario, Canada; 6Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Zurich ETH, Zurich, Switzerland; 7University of Zagreb, School of Medicine, Andrija Štampar School of Public Health, WHO Collaborative Centre for Occupational Health, Zagreb, Croatia; 8Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Sandra Hunziker
- 1Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia; 2School of Medicine, University of Zagreb, Zagreb, Croatia; 3Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia; 4Division of Gastroenterology and Nutrition, Zurich University Children's Hospital, Zurich, Switzerland; 5Iodine Global Network, Ottawa, Ontario, Canada; 6Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Zurich ETH, Zurich, Switzerland; 7University of Zagreb, School of Medicine, Andrija Štampar School of Public Health, WHO Collaborative Centre for Occupational Health, Zagreb, Croatia; 8Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Milan Milošević
- 1Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia; 2School of Medicine, University of Zagreb, Zagreb, Croatia; 3Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia; 4Division of Gastroenterology and Nutrition, Zurich University Children's Hospital, Zurich, Switzerland; 5Iodine Global Network, Ottawa, Ontario, Canada; 6Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Zurich ETH, Zurich, Switzerland; 7University of Zagreb, School of Medicine, Andrija Štampar School of Public Health, WHO Collaborative Centre for Occupational Health, Zagreb, Croatia; 8Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Zvonko Kusić
- 1Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia; 2School of Medicine, University of Zagreb, Zagreb, Croatia; 3Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia; 4Division of Gastroenterology and Nutrition, Zurich University Children's Hospital, Zurich, Switzerland; 5Iodine Global Network, Ottawa, Ontario, Canada; 6Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Zurich ETH, Zurich, Switzerland; 7University of Zagreb, School of Medicine, Andrija Štampar School of Public Health, WHO Collaborative Centre for Occupational Health, Zagreb, Croatia; 8Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Tomislav Jukić
- 1Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia; 2School of Medicine, University of Zagreb, Zagreb, Croatia; 3Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia; 4Division of Gastroenterology and Nutrition, Zurich University Children's Hospital, Zurich, Switzerland; 5Iodine Global Network, Ottawa, Ontario, Canada; 6Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Zurich ETH, Zurich, Switzerland; 7University of Zagreb, School of Medicine, Andrija Štampar School of Public Health, WHO Collaborative Centre for Occupational Health, Zagreb, Croatia; 8Croatian Academy of Sciences and Arts, Zagreb, Croatia
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Eriksen KG, Andersson M, Hunziker S, Zimmermann MB, Moore SE. Effects of an Iodine-Containing Prenatal Multiple Micronutrient on Maternal and Infant Iodine Status and Thyroid Function: A Randomized Trial in The Gambia. Thyroid 2020; 30:1355-1365. [PMID: 32183608 PMCID: PMC7482118 DOI: 10.1089/thy.2019.0789] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background: Iodine supplementation is recommended to pregnant women in iodine-deficient populations, but the impact in moderate iodine deficiency is uncertain. We assessed the effect of an iodine-containing prenatal multiple micronutrient (MMN) supplement in a rural Gambian population at risk of moderate iodine deficiency. Materials and Methods: This study uses data and samples collected as a part of the randomized controlled trial Early Nutrition and Immune Development (ENID; ISRCTN49285450) conducted in Keneba, The Gambia. Pregnant women (<20 weeks gestation) were randomized to either a daily supplement of MMNs containing 300 μg of iodine or an iron and folic acid (FeFol) supplement. Randomization was double blinded (participants and investigators). The coprimary outcomes were maternal urinary iodine concentration (UIC) and serum thyroglobulin (Tg), assessed at baseline and at 30 weeks' gestation. Secondary outcomes were maternal serum thyrotropin (TSH), total triiodothyronine (TT3), total thyroxine (TT4) (assessed at baseline and at 30 weeks' gestation), breast milk iodine concentration (BMIC) (assessed at 8, 12, and 24 weeks postpartum), infant serum Tg (assessed at birth [cord], 12, and 24 weeks postpartum), and serum TSH (assessed at birth [cord]). The effect of supplementation was evaluated using mixed effects models. Results: A total of 875 pregnant women were enrolled between April 2010 and February 2015. In this secondary analysis, we included women from the MMN (n = 219) and FeFol (n = 219) arm of the ENID trial. At baseline, median (interquartile range or IQR) maternal UIC and Tg was 51 μg/L (33-82) and 22 μg/L (12-39), respectively, indicating moderate iodine deficiency. Maternal MMN supplement increased maternal UIC (p < 0.001), decreased maternal Tg (p < 0.001), and cord blood Tg (p < 0.001) compared with FeFol. Maternal thyroid function tests (TSH, TT3, TT4, and TT3/TT4 ratio) and BMIC did not differ according to maternal supplement group over the course of the study. Median (IQR) BMIC, maternal UIC, and infant Tg in the MMN group were 51 μg/L (35-72), 39 μg/L (25-64), and 87 μg/L (59-127), respectively, at 12 weeks postpartum, and did not differ between supplement groups. Conclusions: Supplementing moderately iodine-deficient women during pregnancy improved maternal iodine status and reduced Tg concentration. However, the effects were not attained postpartum and maternal and infant iodine nutrition remained inadequate during the first six months after birth. Consideration should be given to ensuring adequate maternal status through pregnancy and lactation in populations with moderate deficiency.
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Affiliation(s)
- Kamilla G. Eriksen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
- Address correspondence to: Kamilla G. Eriksen, PhD, Department of Nutrition, Exercise and Sports, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Copenhagen, Denmark
| | - Maria Andersson
- Division of Gastroenterology and Nutrition, Children's Research Centre, University Children's Hospital Zurich, Zurich, Switzerland
| | - Sandra Hunziker
- Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Michael B. Zimmermann
- Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Sophie E. Moore
- Department of Women and Children's Health, King's College London, London, United Kingdom
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11
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Rodriguez-Diaz E, Pearce EN. Iodine status and supplementation before, during, and after pregnancy. Best Pract Res Clin Endocrinol Metab 2020; 34:101430. [PMID: 32792134 DOI: 10.1016/j.beem.2020.101430] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Iodine intake is essential for the production of thyroid hormone. Iodine deficiency remains a public health problem in many regions around the world. Iodine deficiency can present as a spectrum of disorders depending on the degree of severity. Pregnant and lactating women are particularly vulnerable to iodine deficiency disorders because of their increased iodine requirements. Severe maternal iodine deficiency has been associated with cretinism or impaired neurodevelopment in children as well as obstetric complications. Universal salt iodization has been shown to prevent these disorders in severely iodine deficient areas. Recently, observational studies have demonstrated an association between mild-to-moderate iodine deficiency and poorer cognitive outcomes in children. In this review, we describe the iodine requirements for pregnant and lactating women, how population iodine status can be assessed, the effects of maternal iodine deficiency and excess, and current data regarding efficacy of iodine supplementation for women who are pregnant or lactating.
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Affiliation(s)
- Eduardo Rodriguez-Diaz
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, 720 Harrison Avenue Suite 8100, Boston, MA 02118, USA.
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, 720 Harrison Avenue Suite 8100, Boston, MA 02118, USA.
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12
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Manousou S, Andersson M, Eggertsen R, Hunziker S, Hulthén L, Nyström HF. Iodine deficiency in pregnant women in Sweden: a national cross-sectional study. Eur J Nutr 2019; 59:2535-2545. [PMID: 31616973 PMCID: PMC7413865 DOI: 10.1007/s00394-019-02102-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 09/26/2019] [Indexed: 01/20/2023]
Abstract
Purpose Voluntary salt iodization at 50 mg/kg salt ensures adequate iodine nutrition in Swedish school-aged children, but iodine status in pregnant women is uncertain. Methods We conducted a cross-sectional national study of 743 pregnant women, at median gestational age of 23 weeks (IQR 9, 38), recruited from maternal health care centers. We measured: urinary iodine concentration (UIC) and urinary creatinine concentration in spot urine samples; thyroglobulin (Tg), thyroid-stimulating hormone (TSH), and total thyroxine (tT4) on dried blood spots (DBS); and thyreoperoxidase antibodies in serum samples. Data on dietary supplement use were obtained, and women were classified as supplement users (consuming multivitamins containing ≥ 150 µg iodine/day) and non-supplement users (no supplements or < 150 µg iodine/day from supplements). Results Overall median UIC [bootstrapped 95% confidence interval (CI)] was 101 µg/L (95, 108; n = 737): 149 µg/L (132, 164) in supplement users (n = 253) and 85 µg/L (79, 92) in non-supplement users (n = 440) (p < 0.001). Overall geometric mean DBS-Tg (95% CI) was 22.1 μg/L (20.8, 23.5; n = 675) and the prevalence of elevated DBS-Tg was 19%. DBS-Tg was lower in supplement users (n = 229) than in non-supplement users (n = 405) (19.1 vs 24.4 μg/L, p < 0.001). DBS-TSH, DBS-tT4, and S-TPOab positivity did not differ between the two groups. Conclusions Pregnant women in Sweden have inadequate iodine nutrition. Women not taking iodine supplements containing ≥ 150 µg iodine/day are affected by mild iodine deficiency and are at higher risk for increased thyroid activity, while maintaining euthyroidism. Iodine intake should be improved in women both before and after conception by promotion of iodized salt instead of non-iodized salt. We urge regular monitoring of iodine status in the general Swedish population, as well as in risk groups.
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Affiliation(s)
- Sofia Manousou
- Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden. .,Frölunda Specialist Hospital, Marconigatan 31, 42144, Västra Frölunda, Sweden.
| | - Maria Andersson
- Division of Gastroenterology and Nutrition, University Children's Hospital Zurich, Eleonore Foundation, Steinwiesstrasse 75, 8032, Zurich, Switzerland.,Iodine Global Network, Ottawa, ON, Canada
| | - Robert Eggertsen
- Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.,Mölnlycke Health Care Centre, Ekdalavägen 2, 43530, Mölnlycke, Sweden
| | - Sandra Hunziker
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland
| | - Lena Hulthén
- Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.,Department of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, University of Gothenburg, Medicinaregatan 13, 40530, Gothenburg, Sweden
| | - Helena Filipsson Nyström
- Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.,Department of Endocrinology, Sahlgrenska University Hospital, Gröna Stråket 8, 41345, Gothenburg, Sweden
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13
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van der Reijden OL, Galetti V, Bürki S, Zeder C, Krzystek A, Haldimann M, Berard J, Zimmermann MB, Herter-Aeberli I. Iodine bioavailability from cow milk: a randomized, crossover balance study in healthy iodine-replete adults. Am J Clin Nutr 2019; 110:102-110. [PMID: 31788697 DOI: 10.1093/ajcn/nqz092] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/19/2019] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Milk and dairy products are considered important dietary sources of iodine in many countries. However, to our knowledge, iodine bioavailability from milk has not been directly measured in humans. OBJECTIVE The aim of this study was to compare iodine bioavailability in iodine-replete adults from: 1) cow milk containing a high concentration of native iodine; 2) milk containing a low concentration of native iodine, with the addition of potassium iodide (KI) to assess a potential matrix effect; and 3) an aqueous solution of KI as a comparator; with all 3 containing equal amounts of total iodine (263 µg/250 mL). We also speciated iodine in milk. DESIGN We conducted a 3-wk, randomized, crossover balance study in adults (n = 12) consuming directly analyzed, standardized diets. During the 3 test conditions - high intrinsic iodine milk (IIM), extrinsically added iodine in milk (EIM), and aqueous iodine solution (AIS) - subjects collected 24-h urine over 3 d and consumed the test drink on the second day, with 3- or 4-d wash-out periods prior to each treatment. Iodine absorption was calculated as the ratio of urinary iodine excretion (UIE) to total iodine intake. Milk iodine speciation was performed using ion chromatography-mass spectrometry. RESULTS Iodine intake from the standardized diet was 195 ± 6 µg/d for males and 107 ± 6 µg/d for females; the test drinks provided an additional 263 µg. Eleven subjects completed the protocol. There was a linear relation between iodine intake and UIE (β = 0.89, SE = 0.04, P < 0.001). There were no significant differences in UIE among the 3 conditions (P = 0.24). Median (range) fractional iodine absorption across the 3 conditions was 91 (51-145), 72 (48-95), and 98 (51-143)% on days 1, 2, and 3, respectively, with day 2 significantly lower compared with days 1 and 3 (P < 0.001). In milk, 80-93% of the total iodine was inorganic iodide. CONCLUSION Nearly all of the iodine in cow milk is iodide and although fractional iodine absorption from milk decreases with increasing dose, its bioavailability is high. The trial was registered at clinicaltrials.gov as NCT03590431.
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Affiliation(s)
- Olivia L van der Reijden
- ETH Zurich, Institute of Food, Nutrition and Health, Laboratory of Human Nutrition, Zurich, Switzerland
| | - Valeria Galetti
- ETH Zurich, Institute of Food, Nutrition and Health, Laboratory of Human Nutrition, Zurich, Switzerland
| | - Sarah Bürki
- ETH Zurich, Institute of Food, Nutrition and Health, Laboratory of Human Nutrition, Zurich, Switzerland
| | - Christophe Zeder
- ETH Zurich, Institute of Food, Nutrition and Health, Laboratory of Human Nutrition, Zurich, Switzerland
| | - Adam Krzystek
- ETH Zurich, Institute of Food, Nutrition and Health, Laboratory of Human Nutrition, Zurich, Switzerland
| | - Max Haldimann
- Federal Food Safety and Veterinary Office, Division of Risk Assessment, Bern, Switzerland
| | - Joel Berard
- ETH Zurich, AgroVet-Strickhof, Lindau, Switzerland
| | - Michael B Zimmermann
- ETH Zurich, Institute of Food, Nutrition and Health, Laboratory of Human Nutrition, Zurich, Switzerland
| | - Isabelle Herter-Aeberli
- ETH Zurich, Institute of Food, Nutrition and Health, Laboratory of Human Nutrition, Zurich, Switzerland
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14
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Effectiveness of increased salt iodine concentration on iodine status: trend analysis of cross-sectional national studies in Switzerland. Eur J Nutr 2019; 59:581-593. [PMID: 30843107 DOI: 10.1007/s00394-019-01927-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 02/06/2019] [Indexed: 01/26/2023]
Abstract
PURPOSE Despite longstanding voluntary salt iodisation in Switzerland, data suggest inadequate iodine intake in vulnerable population groups. In response, the salt iodine concentration was increased from 20 to 25 mg/kg and we assessed the impact on iodine status. METHODS We conducted a cross-sectional national study in school-age children (n = 731), women of reproductive age (n = 353) and pregnant women (n = 363). We measured urinary iodine concentration (UIC) and urinary sodium concentration (UNaC) in spot urine samples. The current median UIC was compared with national data from 1999, 2004 and 2009. We measured TSH, total T4 and thyroglobulin (Tg) on dried blood spot samples collected in women. RESULTS The median UIC (bootstrapped 95% CI) was 137 µg/L (131, 143 µg/L) in school children, 88 µg/L (72, 103 µg/L) in women of reproductive age and 140 µg/L (124, 159 µg/L) in pregnant women. Compared to 2009, the median UIC increased modestly in school children (P < 0.001), but did not significantly change in pregnant women (P = 0.417). Estimated sodium intake exceeded the recommendations in all population groups. The prevalence of thyroid disorders in women was low, but Tg was elevated in 13% of the pregnant women. CONCLUSION Iodine intake is overall adequate in Swiss school-age children, but only borderline sufficient in pregnant and non-pregnant women, despite high salt intakes and satisfactory household coverage with iodized salt. Our findings suggest increasing the concentration of iodine in salt may not improve iodine intakes in women if iodised salt is not widely used in processed foods. REGISTRATION This trial was registered at clinicaltrials.gov as NCT02312466.
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15
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Farebrother J, Zimmermann MB, Assey V, Castro MC, Cherkaoui M, Fingerhut R, Jia Q, Jukic T, Makokha A, San Luis TO, Wegmüller R, Andersson M. Thyroglobulin Is Markedly Elevated in 6- to 24-Month-Old Infants at Both Low and High Iodine Intakes and Suggests a Narrow Optimal Iodine Intake Range. Thyroid 2019; 29:268-277. [PMID: 30648484 DOI: 10.1089/thy.2018.0321] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND In areas with incomplete salt iodization coverage, infants and children aged 6-24 months weaning from breast milk and receiving complementary foods are at risk of iodine deficiency. However, few data exist on the risk of excessive iodine intake in this age group. Thyroglobulin (Tg) is a sensitive marker of iodine intake in school-age children and adults and may be used to estimate the optimal iodine intake range in infancy. The aim of this study was to assess the association of low and high iodine intakes with Tg and thyroid function in weaning infants. METHODS This multicenter cross-sectional study recruited infants aged 6-24 months (n = 1543; Mage = 12.2 ± 4.6 months) receiving breast milk with complementary foods, from seven countries in areas with previously documented deficient, sufficient, or excessive iodine intake in schoolchildren or pregnant women. Urinary iodine concentration (UIC) and Tg, total thyroxine, and thyrotropin were measured using dried blood spot testing. RESULTS Median UIC ranged from 48 μg/L (interquartile range 31-79 μg/L) to 552 μg/L (interquartile range 272-987 μg/L) across the study sites. Median Tg using dried blood spot testing was high (>50 μg/L) at estimated habitual iodine intakes <50 μg/day and >230 μg/day. Prevalence of overt thyroid disorders was low (<3%). Yet, subclinical hyperthyroidism was observed in the countries with the lowest iodine intake. CONCLUSIONS Tg is a sensitive biomarker of iodine intake in 6- to 24-month-old infants and follows a U-shaped relationship with iodine intake, suggesting a relatively narrow optimal intake range. Infants with low iodine intake may be at increased risk of subclinical thyroid dysfunction. In population monitoring of iodine deficiency or excess, assessment of iodine status using UIC and Tg may be valuable in this young age group.
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Affiliation(s)
- Jessica Farebrother
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
| | - Michael B Zimmermann
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
| | - Vincent Assey
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 3 Nutrition Services Section, Preventive Services Department; Ministry of Health, Community Development, Gender, Elderly, and Children, Dar es Salaam, Tanzania
| | | | - Mohamed Cherkaoui
- 5 Faculté des Sciences Semlalia, Université Caddi Ayyed, Marrakech, Morocco
| | - Ralph Fingerhut
- 6 Swiss Newborn Screening Laboratory and Children's Research Center; University Children's Hospital Zurich, Zurich, Switzerland
| | - Qingzhen Jia
- 7 Shanxi Institute for Prevention and Treatment of Endemic Disease, Linfen, P.R. China
| | - Tomislav Jukic
- 8 Department of Nuclear Medicine and Oncology, Sestre Milosrdnice University Hospital Center and School of Medicine, University of Zagreb, Zagreb, Croatia
- 9 Faculty of Medicine Osijek, University Josip Juraj Strossmayer Osijek, Osijek, Croatia
| | - Anselimo Makokha
- 10 Department of Food Science, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Theofilo O San Luis
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 11 St Luke's Medical Center, Quezon City, Manila, The Philippines
| | - Rita Wegmüller
- 12 Medical Research Council The Gambia, Keneba, The Gambia
| | - Maria Andersson
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 13 Division of Gastroenterology and Nutrition; University Children's Hospital Zurich, Zurich, Switzerland
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16
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Farebrother J, Zimmermann MB, Abdallah F, Assey V, Fingerhut R, Gichohi-Wainaina WN, Hussein I, Makokha A, Sagno K, Untoro J, Watts M, Andersson M. Effect of Excess Iodine Intake from Iodized Salt and/or Groundwater Iodine on Thyroid Function in Nonpregnant and Pregnant Women, Infants, and Children: A Multicenter Study in East Africa. Thyroid 2018; 28:1198-1210. [PMID: 30019625 DOI: 10.1089/thy.2018.0234] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Acute excess iodine intake can damage the thyroid, but the effects of chronic excess iodine intake are uncertain. Few data exist for pregnant and lactating women and infants exposed to excessive iodine intake. METHODS This was a multicenter cross-sectional study. At study sites in rural Kenya and urban Tanzania previously reporting iodine excess in children, urinary iodine concentration (UIC), thyrotropin, total thyroxine, and thyroglobulin (Tg) were measured in school-age children (SAC), women of reproductive age, pregnant (PW) and lactating women, and breast-feeding and weaning infants. In a national study in Djibouti, UIC was measured in SAC and PW. At all sites, daily iodine intake was estimated based on UIC, and iodine concentration was measured in household salt and drinking water. RESULTS The total sample size was 4636: 1390, 2048, and 1198 subjects from Kenya, Tanzania, and Djibouti, respectively. In Kenya and Tanzania: (i) median UIC was well above thresholds for adequate iodine nutrition in all groups and exceeded the threshold for excess iodine intake in SAC; (ii) iodine concentrations >40 mg of iodine/kg were found in approximately 55% of household salt samples; (iii) iodine concentrations ≥10 μg/L were detected in 9% of drinking water samples; (iv) Tg was elevated in all population groups, but the prevalence of thyroid disorders was negligible, except that 5-12% of women of reproductive age had subclinical hyperthyroidism and 10-15% of PW were hypothyroxinemic. In Djibouti: (i) the median UIC was 335 μg/L (interquartile range [IQR] = 216-493 μg/L) in SAC and 265 μg/L (IQR = 168-449 μg/L) in PW; (ii) only 1.6% of Djibouti salt samples (n = 1200) were adequately iodized (>15 mg/kg); (iii) the median iodine concentration in drinking water was 92 μg/L (IQR = 37-158 μg/L; n = 77). In all countries, UIC was not significantly correlated with salt or water iodine concentrations. CONCLUSIONS Although iodine intake was excessive and Tg concentrations were elevated, there was little impact on thyroid function. Chronic excess iodine intake thus appears to be well tolerated by women, infants, and children. However, such high iodine intake is unnecessary and should be avoided. Careful evaluation of contributions from both iodized salt and groundwater iodine is recommended before any review of iodization policy is considered.
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Affiliation(s)
- Jessica Farebrother
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition, and Health , ETH Zurich, Zurich, Switzerland
| | - Michael B Zimmermann
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition, and Health , ETH Zurich, Zurich, Switzerland
- 2 Iodine Global Network , Ottawa, Canada
| | - Fatma Abdallah
- 3 Tanzania Food and Nutrition Centre , Dar es Salaam, Tanzania
| | - Vincent Assey
- 4 Nutrition Services Section, Preventive Services Department, Ministry of Health , Community Development, Gender, Elderly, and Children, Dar es Salaam, Tanzania
- 5 Regional Coordinator East and Southern Africa, Iodine Global Network , Ottawa, Canada
| | - Ralph Fingerhut
- 6 University Children's Hospital Zurich , Swiss Newborn Screening Laboratory and Children's Research Center, Zurich, Switzerland
| | - Wanjiku N Gichohi-Wainaina
- 7 International Crops Research Institute for Semi-Arid Tropics (ICRISAT) , Lilongwe, Malawi
- 8 Department of Food Science, Jomo Kenyatta University of Agriculture and Technology , Nairobi, Kenya
| | - Izzeldin Hussein
- 9 Regional Coordinator Middle East and North Africa, Iodine Global Network , Ottawa, Canada
| | - Anselimo Makokha
- 8 Department of Food Science, Jomo Kenyatta University of Agriculture and Technology , Nairobi, Kenya
| | - Kalil Sagno
- 10 Djibouti Country Office, United Nations Children's Fund , Djibouti, Djibouti
| | - Juliawati Untoro
- 11 Eastern and Southern Africa Regional Office, United Nations Children's Fund , Nairobi, Kenya
| | - Michael Watts
- 12 Inorganic Geochemistry, Centre for Environmental Geochemistry, British Geological Survey , Nottingham, United Kingdom
| | - Maria Andersson
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition, and Health , ETH Zurich, Zurich, Switzerland
- 2 Iodine Global Network , Ottawa, Canada
- 13 Division of Gastroenterology and Nutrition, University Children's Hospital Zurich , Zurich, Switzerland
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17
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Dold S, Zimmermann MB, Jukic T, Kusic Z, Jia Q, Sang Z, Quirino A, San Luis TOL, Fingerhut R, Kupka R, Timmer A, Garrett GS, Andersson M. Universal Salt Iodization Provides Sufficient Dietary Iodine to Achieve Adequate Iodine Nutrition during the First 1000 Days: A Cross-Sectional Multicenter Study. J Nutr 2018; 148:587-598. [PMID: 29659964 DOI: 10.1093/jn/nxy015] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/16/2018] [Indexed: 12/14/2022] Open
Abstract
Background Dietary iodine requirements are high during pregnancy, lactation, and infancy, making women and infants vulnerable to iodine deficiency. Universal salt iodization (USI) has been remarkably successful for preventing iodine deficiency in the general population, but it is uncertain if USI provides adequate iodine intakes during the first 1000 d. Objective We set out to assess if USI provides sufficient dietary iodine to meet the iodine requirements and achieve adequate iodine nutrition in all vulnerable population groups. Methods We conducted an international, cross-sectional, multicenter study in 3 study sites with mandatory USI legislation. We enrolled 5860 participants from 6 population groups (school-age children, nonpregnant nonlactating women of reproductive age, pregnant women, lactating women, 0-6-mo-old infants, and 7-24-mo-old infants) and assessed iodine status [urinary iodine concentration (UIC)] and thyroid function in Linfen, China (n = 2408), Tuguegarao, the Philippines (n = 2512), and Zagreb, Croatia (n = 940). We analyzed the iodine concentration in household salt, breast milk, drinking water, and cow's milk. Results The salt iodine concentration was low (<15 mg/kg) in 2.7%, 33.6%, and 3.1%, adequate (15-40 mg/kg) in 96.3%, 48.4%, and 96.4%, and high (>40 mg/kg) in 1.0%, 18.0%, and 0.5% of household salt samples in Linfen (n = 402), Tuguegarao (n = 1003), and Zagreb (n = 195), respectively. The median UIC showed adequate iodine nutrition in all population groups, except for excessive iodine intake in school-age children in the Philippines and borderline low intake in pregnant women in Croatia. Conclusions Salt iodization at ∼25 mg/kg that covers a high proportion of the total amount of salt consumed supplies sufficient dietary iodine to ensure adequate iodine nutrition in all population groups, although intakes may be borderline low during pregnancy. Large variations in salt iodine concentrations increase the risk for both low and high iodine intakes. Strict monitoring of the national salt iodization program is therefore essential for optimal iodine nutrition. This trial was registered at clinicaltrials.gov as NCT02196337.
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Affiliation(s)
- Susanne Dold
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Michael B Zimmermann
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich, Switzerland.,Iodine Global Network, Ottawa, Ontario, Canada
| | - Tomislav Jukic
- Department of Nuclear Medicine and Oncology, Sestre Milosrdnice University Hospital Centre and School of Medicine, University of Zagreb, Zagreb, Croatia.,Faculty of Medicine Osijek, University Josip Juraj Strossmayer Osijek, Osijek, Croatia
| | - Zvonko Kusic
- Department of Nuclear Medicine and Oncology, Sestre Milosrdnice University Hospital Centre and School of Medicine, University of Zagreb, Zagreb, Croatia.,Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Qingzhen Jia
- Shanxi Institute for Prevention and Treatment of Endemic Disease, Linfen, China
| | - Zhongna Sang
- Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Antonio Quirino
- Technological Institute of the Philippines, Manila, Philippines
| | | | - Ralph Fingerhut
- Swiss Newborn Screening Laboratory, Division of Metabolism and Children's Research Centre (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| | | | - Arnold Timmer
- Global Alliance for Improved Nutrition (GAIN), Geneva, Switzerland
| | - Greg S Garrett
- Global Alliance for Improved Nutrition (GAIN), Geneva, Switzerland
| | - Maria Andersson
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich, Switzerland.,Iodine Global Network, Ottawa, Ontario, Canada
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18
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Valores de referencia para tiroglobulina sérica en individuos sanos. ENDOCRINOL DIAB NUTR 2018; 65:60-61. [DOI: 10.1016/j.endinu.2017.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 10/05/2017] [Indexed: 11/18/2022]
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19
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Brindle E, Lillis L, Barney R, Hess SY, Wessells KR, Ouédraogo CT, Stinca S, Kalnoky M, Peck R, Tyler A, Lyman C, Boyle DS. Simultaneous assessment of iodine, iron, vitamin A, malarial antigenemia, and inflammation status biomarkers via a multiplex immunoassay method on a population of pregnant women from Niger. PLoS One 2017; 12:e0185868. [PMID: 28982133 PMCID: PMC5628875 DOI: 10.1371/journal.pone.0185868] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/20/2017] [Indexed: 11/24/2022] Open
Abstract
Deficiencies of vitamin A, iron, and iodine are major public health concerns in many low- and middle-income countries, but information on their status in populations is often lacking due to high costs and logistical challenges associated with assessing micronutrient status. Accurate, user-friendly, and low-cost analytical tools are needed to allow large-scale population surveys on micronutrient status. We present the expansion of a 7-plex protein microarray tool for the simultaneous measurement of up to seven biomarkers with relevance to the assessment of the key micronutrients iron, iodine, and vitamin A, and inflammation and malaria biomarkers: α-1-acid glycoprotein, C-reactive protein, ferritin, retinol binding protein 4, soluble transferrin receptor, thyroglobulin, and histidine-rich protein II. Assay performance was assessed using international reference standards and then verified by comparing the multiplexed and conventional immunoassay results on a training panel of plasma samples collected from US adults. These data were used to assign nominal concentrations to the calibrators of the assay to further improve performance which was then assessed by interrogating plasma samples from a cohort of pregnant women from Niger. The correlation between assays for each biomarker measured from this cohort was typically good, with the exception of thyroglobulin, and the sensitivity ranged from 74% to 93%, and specificity from 81% to 98%. The 7-Plex micronutrient assay has the potential for use as an affordable tool for population surveillance of vitamin A, iron, and iodine deficiencies as well as falciparum malarial parasitemia infectivity and inflammation. The assay is easy-to-use, requires minimal sample volume, and is scalable, rapid, and accurate—needing only a low-cost reader and basic equipment present in most reference laboratory settings and so may be employed by low and middle income countries for micronutrient surveillance to inform on status in key populations. Micronutrient deficiencies including iron, iodine, and vitamin A affect a significant portion of the world’s population. Efforts to assess the prevalence of these deficiencies in vulnerable populations are challenging, partly due to measurement tools that are inadequate for assessing multiple micronutrients in large-scale population surveys. We have developed a 7-plex immunoassay for the simultaneous measurement of seven biomarkers relevant to assessing iodine, iron, and vitamin A status, inflammation and Plasmodium falciparum parasitemia by measuring levels of thyroglobulin, ferritin, soluble transferrin receptor, retinol binding protein 4, α-1-acid glycoprotein, C-reactive protein, and histidine-rich protein II. This 7-plex immunoassay technique has potential as a rapid and effective tool for use in large-scale surveys and assessments of nutrition intervention programs in low- and middle-income countries.
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Affiliation(s)
- Eleanor Brindle
- Center for Studies in Demography and Ecology, University of Washington, Seattle, WA, United States of America
| | | | | | - Sonja Y. Hess
- Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, United States of America
| | - K. Ryan Wessells
- Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, United States of America
| | - Césaire T. Ouédraogo
- Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, United States of America
- Helen Keller International, Niamey, Niger
| | - Sara Stinca
- Laboratory of Human Nutrition, Swiss Federal Institute of Technology, Zurich, Switzerland
| | | | - Roger Peck
- PATH, Seattle, WA, United States of America
| | - Abby Tyler
- Quansys Biosciences, Logan, Utah, United States of America
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Dold S, Zimmermann MB, Aboussad A, Cherkaoui M, Jia Q, Jukic T, Kusic Z, Quirino A, Sang Z, San Luis TO, Vandea E, Andersson M. Breast Milk Iodine Concentration Is a More Accurate Biomarker of Iodine Status Than Urinary Iodine Concentration in Exclusively Breastfeeding Women. J Nutr 2017; 147:528-537. [PMID: 28228508 DOI: 10.3945/jn.116.242560] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/06/2016] [Accepted: 01/23/2017] [Indexed: 11/14/2022] Open
Abstract
Background: Iodine status in populations is usually assessed by the median urinary iodine concentration (UIC). However, iodine is also excreted in breast milk during lactation; thus, breast milk iodine concentration (BMIC) may be a promising biomarker of iodine nutrition in lactating women. Whether the mammary gland can vary fractional uptake of circulating iodine in response to changes in dietary intake is unclear.Objective: We evaluated UIC and BMIC as biomarkers for iodine status in lactating women with a wide range of iodine intakes.Methods: We recruited 866 pairs of lactating mothers and exclusively breastfed infants from 3 iodine-sufficient study sites: Linfen, China (n = 386); Tuguegarao, Philippines (n = 371); and Zagreb, Croatia (n = 109). We also recruited iodine-deficient lactating women from Amizmiz, Morocco (n = 117). We collected urine and breast milk samples and measured UIC and BMIC.Results: In the 3 iodine-sufficient sites, a pooled regression analysis of the estimated iodine excretion revealed higher fractional iodine excretion in breast milk than in urine at borderline low iodine intakes. In contrast, in the iodine-deficient site in Morocco, a constant proportion (∼33%) of total iodine was excreted into breast milk.Conclusions: In iodine-sufficient populations, when iodine intake in lactating women is low, there is increased partitioning of iodine into breast milk. For this reason, maternal UIC alone may not reflect iodine status, and BMIC should also be measured to assess iodine status in lactating women. Our data suggest a BMIC reference range (2.5th and 97.5th percentiles) of 60-465 μg/kg in exclusively breastfeeding women. This trial was registered at clinicaltrials.gov as NCT02196337.
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Affiliation(s)
- Susanne Dold
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland;
| | - Michael B Zimmermann
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.,Iodine Global Network, Ottawa, Canada
| | | | - Mohamed Cherkaoui
- Laboratory of Human Ecology, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
| | - Qingzhen Jia
- Shanxi Institute for Prevention and Treatment of Endemic Disease, Linfen, China
| | - Tomislav Jukic
- Department of Nuclear Medicine and Oncology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Zvonko Kusic
- Department of Nuclear Medicine and Oncology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Antonio Quirino
- St. Luke's Medical Center, Quezon City, Manila, Philippines; and
| | - Zhongna Sang
- Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | | | - Elena Vandea
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Maria Andersson
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.,Iodine Global Network, Ottawa, Canada
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21
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Ma ZF, Venn BJ, Manning PJ, Cameron CM, Skeaff SA. The sensitivity and specificity of thyroglobulin concentration using repeated measures of urinary iodine excretion. Eur J Nutr 2017; 57:1313-1320. [DOI: 10.1007/s00394-017-1410-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 02/19/2017] [Indexed: 10/20/2022]
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Bath SC, Pop VJM, Furmidge-Owen VL, Broeren MAC, Rayman MP. Thyroglobulin as a Functional Biomarker of Iodine Status in a Cohort Study of Pregnant Women in the United Kingdom. Thyroid 2017; 27:426-433. [PMID: 27762729 PMCID: PMC5337401 DOI: 10.1089/thy.2016.0322] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Though iodine deficiency in pregnancy is a matter of public-health concern, a functional measure of iodine status is lacking. The thyroid-specific protein thyroglobulin (Tg), which reflects thyroid size, has shown promise as a functional measure in studies of children and adults, but data in pregnancy are sparse. In a cohort of mildly to moderately iodine-deficient pregnant women, this study aimed to explore whether serum Tg is a sensitive functional biomarker of iodine status and to examine longitudinal change in Tg with gestational age. METHOD A total of 230 pregnant women were recruited at an antenatal clinic at 12 weeks of gestation to the Selenium in PRegnancy INTervention study, in Oxford, United Kingdom. Repeated measures of urinary iodine-to-creatinine ratio, serum thyrotropin (TSH), and Tg at 12, 20, and 35 weeks of gestation were made. Women were dichotomized by their iodine-to-creatinine ratio (<150 or ≥150 μg/g) to group them broadly as iodine deficient or iodine sufficient. Women with thyroid antibodies were excluded; data and samples were available for 191 women. RESULTS Median Tg concentrations were 21, 19, and 23 μg/L in the first, second, and third trimesters, respectively. In a linear mixed model, controlling for confounders, Tg was higher in the <150 μg/g group than it was in the ≥150 μg/g group (p < 0.001) but there was no difference in TSH (p = 0.27). Gestational week modified the effect of iodine status on TSH (p = 0.01) and Tg (p = 0.012); Tg did not increase with gestational week in the ≥150 μg/g group, but it did in the <150 μg/g group, and TSH increased more steeply in the <150 μg/g group. CONCLUSIONS Low iodine status (<150 μg/g) in pregnancy is associated with higher serum Tg, suggesting that the thyroid is hyperstimulated by iodine deficiency, which causes it to enlarge. Tg is a more sensitive biomarker of iodine status in pregnancy than is TSH.
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Affiliation(s)
- Sarah C Bath
- 1 Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey , Guildford, United Kingdom
| | - Victor J M Pop
- 2 Department of Primary Care, University of Tilburg , Tilburg, The Netherlands
| | - Victoria L Furmidge-Owen
- 1 Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey , Guildford, United Kingdom
- 3 Danone Nutricia Early Life Nutrition , Trowbridge, United Kingdom
| | - Maarten A C Broeren
- 4 Department of Clinical Chemistry, Máxima Medical Center , Veldhoven, The Netherlands
| | - Margaret P Rayman
- 1 Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey , Guildford, United Kingdom
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23
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Stinca S, Andersson M, Weibel S, Herter-Aeberli I, Fingerhut R, Gowachirapant S, Hess SY, Jaiswal N, Jukic T, Kusic Z, Mabapa NS, Nepal AK, San Luis TOL, Zhen JQ, Zimmermann MB. Dried Blood Spot Thyroglobulin as a Biomarker of Iodine Status in Pregnant Women. J Clin Endocrinol Metab 2017; 102:23-32. [PMID: 27732337 DOI: 10.1210/jc.2016-2829] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 10/06/2016] [Indexed: 11/19/2022]
Abstract
CONTEXT Thyroglobulin (Tg) could be a sensitive biomarker of iodine nutrition in pregnant women (PW). A dried blood spot (DBS) assay would simplify collection and transport in field studies. OBJECTIVES Our aims were to (1) establish and test a reference range for DBS-Tg in PW; (2) determine whether co-measurement of Tg antibodies (Abs) is necessary to define population iodine status. DESIGN, SETTING, AND PARTICIPANTS Standardized cross-sectional studies of 3870 PW from 11 countries. For the DBS-Tg reference range, we included TgAb-negative PW (n = 599) from 3 countries with sufficient iodine intake. MAIN OUTCOME MEASURES We measured the urinary iodine concentration and DBS thyroid-stimulating hormone, total thyroxin, Tg, and TgAb. RESULTS In the reference population, the median DBS-Tg was 9.2 μg/L (95% confidence interval, 8.7 to 9.8 μg/L) and was not significantly different among trimesters. The reference range was 0.3 to 43.5 μg/L. Over a range of iodine intake, the Tg concentrations were U-shaped. Within countries, the median DBS-Tg and the presence of elevated DBS-Tg did not differ significantly between all PW and PW who were TgAb-negative. CONCLUSIONS A median DBS-Tg of ∼10 μg/L with <3% of values ≥44 μg/L indicated population iodine sufficiency. Concurrent measurement of TgAb did not appear necessary to assess the population iodine status.
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Affiliation(s)
- Sara Stinca
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
| | - Maria Andersson
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
| | - Sandra Weibel
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
| | - Isabelle Herter-Aeberli
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
| | - Ralph Fingerhut
- Swiss Newborn Screening Laboratory, Children's Research Center (CRC), University Children's Hospital of Zurich, Zurich 8032, Switzerland
| | | | - Sonja Y Hess
- Department of Nutrition, University of California, Davis, Davis, California 95616
| | - Nidhi Jaiswal
- St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore 560034, India
| | - Tomislav Jukic
- Department of Oncology and Nuclear Medicine, University of Zagreb School of Medicine, Sisters of Charity University Hospital Centre, Zagreb 10,000, Croatia
| | - Zvonko Kusic
- Department of Oncology and Nuclear Medicine, University of Zagreb School of Medicine, Sisters of Charity University Hospital Centre, Zagreb 10,000, Croatia
| | | | - Ashwini Kumar Nepal
- Department of Biochemistry, B.P. Koirala Institute of Health Sciences, Ghopa, Dharan 56700, Nepal
| | | | - Jia Qing Zhen
- Shanxi Institute for Endemic Disease Prevention and Treatment, LinFen 041000, China
| | - Michael Bruce Zimmermann
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
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Urinary iodine concentration identifies pregnant women as iodine deficient yet school-aged children as iodine sufficient in rural Niger. Public Health Nutr 2016; 20:1154-1161. [PMID: 27974077 DOI: 10.1017/s1368980016003232] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To assess iodine status among pregnant women in rural Zinder, Niger and to compare their status with the iodine status of school-aged children from the same households. DESIGN Seventy-three villages in the catchment area of sixteen health centres were randomly selected to participate in the cross-sectional survey. SETTING Salt iodization is mandatory in Niger, requiring 20-60 ppm iodine at the retail level. SUBJECTS A spot urine sample was collected from randomly selected pregnant women (n 662) and one school-aged child from the same household (n 373). Urinary iodine concentration (UIC) was assessed as an indicator of iodine status in both groups. Dried blood spots (DBS) were collected from venous blood samples of pregnant women and thyroglobulin (Tg), thyroid-stimulating hormone and total thyroxine were measured. Iodine content of household salt samples (n 108) was assessed by titration. RESULTS Median iodine content of salt samples was 5·5 ppm (range 0-41 ppm), 98 % had an iodine content 40 µg/l. CONCLUSIONS In this region of Niger, most salt is inadequately iodized. UIC in pregnant women indicated iodine deficiency, whereas UIC of school-aged children indicated marginally adequate iodine status. Thus, estimating population iodine status based solely on monitoring of UIC among school-aged children may underestimate the risk of iodine deficiency in pregnant women.
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25
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Osei J, Andersson M, Reijden OVD, Dold S, Smuts CM, Baumgartner J. Breast-Milk Iodine Concentrations, Iodine Status, and Thyroid Function of Breastfed Infants Aged 2-4 Months and Their Mothers Residing in a South African Township. J Clin Res Pediatr Endocrinol 2016; 8:381-391. [PMID: 27217155 PMCID: PMC5197995 DOI: 10.4274/jcrpe.2720] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 05/22/2016] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE Lactating women and their infants are susceptible to iodine deficiency and iodine excess. In South Africa, no data exist on the iodine status and thyroid function of these vulnerable groups. METHODS In a cross-sectional study, urinary iodine concentrations (UIC), thyroid function, and breast-milk iodine concentrations (BMIC) were assessed in 100 lactating women from a South African township and their 2-4-month-old breastfed infants. Potential predictors of UIC, thyroid function, and BMIC, including household salt iodine concentrations (SIC) and maternal sodium excretion, were also investigated. RESULTS The median (25th-75th percentile) UIC was 373 (202-627) μg/L in infants and 118 (67-179) μg/L in mothers. Median household SIC was 44 (27-63) ppm. Household SIC and maternal urinary sodium excretion predicted UIC of lactating mothers. Median BMIC was 179 (126-269) μg/L. Age of infants, SIC, and maternal UIC predicted BMIC. In turn, infant age and BMIC predicted UIC of infants. Forty-two percent of SIC values were within the South African recommended salt iodine fortification level at production of 35-65 ppm, whilst 21% of SIC were >65 ppm. Thyroid-stimulating hormone, total thyroxine, and thyroglobulin concentrations in the dried whole blood spot specimens from the infants were 1.3 (0.8-1.9) mU/L, 128±33 mmol/L, and 77.1 (56.3-105.7) μg/L, respectively, and did not correlate with infant UIC or BMIC. CONCLUSION Our results suggest that the salt fortification program in South Africa provides adequate iodine to lactating women and indirectly to their infants via breast milk. However, monitoring of salt iodine content of the mandatory salt iodization program in South Africa is important to avoid over-iodization of salt.
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Affiliation(s)
- Jennifer Osei
- North-West University, Centre of Excellence for Nutrition, Potchefstroom, South Africa, Phone: +27 18 299 40 11 E-mail:
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Wang Z, Zhang H, Zhang X, Sun J, Han C, Li C, Li Y, Teng X, Fan C, Liu A, Shan Z, Liu C, Weng J, Teng W. Serum thyroglobulin reference intervals in regions with adequate and more than adequate iodine intake. Medicine (Baltimore) 2016; 95:e5273. [PMID: 27902589 PMCID: PMC5134814 DOI: 10.1097/md.0000000000005273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The purpose of this study was to establish normal thyroglobulin (Tg) reference intervals (RIs) in regions with adequate and more than adequate iodine intake according to the National Academy of Clinical Biochemistry (NACB) guidelines and to investigate the relationships between Tg and other factors.A total of 1317 thyroid disease-free adult subjects (578 men, 739 nonpregnant women) from 2 cities (Guangzhou and Nanjing) were enrolled in this retrospective, observational study. Each subject completed a questionnaire and underwent physical and ultrasonic examination. Serum Tg, thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), Tg antibody (TgAb), and urinary iodine concentration (UIC) were measured. Reference groups were established on the basis of TSH levels: 0.5 to 2.0 and 0.27 to 4.2 mIU/L.The Tg RIs for Guangzhou and Nanjing were 1.6 to 30.0 and 1.9 to 25.8 ng/mL, respectively. No significant differences in Tg were found between genders or among different reference groups. Stepwise linear regression analyses showed that TgAb, thyroid volume, goiter, gender, age, and TSH levels were correlated with Tg.In adults from regions with adequate and more than adequate iodine intake, we found that Tg may be a suitable marker of iodine status; gender-specific Tg RI was unnecessary; there was no difference between Tg RIs in regions with adequate and more than adequate iodine intake; and the TSH criterion for selecting the Tg reference population could follow the local TSH reference rather than 0.5 to 2.0 mIU/L.
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Affiliation(s)
- Zhaojun Wang
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Hanyi Zhang
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Xiaowen Zhang
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Jie Sun
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Cheng Han
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Chenyan Li
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Yongze Li
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Xiaochun Teng
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Chenling Fan
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Aihua Liu
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Zhongyan Shan
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
| | - Chao Liu
- Department of Endocrinology and Metabolism, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing University of Traditional Chinese Medicine, Jiangsu
| | - Jianping Weng
- Guangdong Provincial Key Laboratory of Diabetology, Department of Endocrinology and Metabolic Disease, The Third Affiliated Hospital of Sun Yat-Sen University, Guangdong, China
| | - Weiping Teng
- The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Liaoning
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Krejbjerg A, Bjergved L, Bülow Pedersen I, Carlé A, Knudsen N, Perrild H, Ovesen L, Banke Rasmussen L, Laurberg P. Serum thyroglobulin as a biomarker of iodine deficiency in adult populations. Clin Endocrinol (Oxf) 2016; 85:475-82. [PMID: 26851767 DOI: 10.1111/cen.13037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 01/13/2016] [Accepted: 02/02/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To clarify which factors may influence the serum Tg level in an adult population and how this may affect Tg as a biomarker of iodine deficiency (ID). DESIGN AND METHODS Two identical cross-sectional studies were performed before (C1a: 1997-98, n = 4649) and after (C2: 2004-05, n = 3570) the Danish mandatory iodine fortification (IF) of salt (2000). Additionally, a follow-up study of C1a was performed after IF (C1b: 2008-10, n = 2465). The studies took place in two regions with mild (Copenhagen) and moderate (Aalborg) ID before IF. Serum Tg was measured by immunoradiometric method and investigated as outcome variable in multivariate models. RESULTS Multiple factors were associated with serum Tg. Some were directly related to iodine intake (cohort, urinary iodine concentration (UIC) level and region), and some were likely mediators of iodine intake effects on Tg (thyroid nodularity, thyroid size and autonomy with low TSH). Others were caused by Tg assay interference (Tg-Ab positivity), aggravation of ID (childbirths and smoking) or TSH stimulation of the thyroid. Estimated 24-h urinary iodine excretion was a more sensitive predictor of Tg than UIC. Iodine supplement users had low median Tg values compared with nonusers both before and after IF. CONCLUSIONS Multiple factors should be taken into consideration when evaluating Tg as a marker of ID in adult populations, and the Tg results may depend on the assay used. Still, Tg is a sensitive marker of ID. We suggest including a reference population with known sufficient iodine intake when Tg is used to evaluate ID.
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Affiliation(s)
- Anne Krejbjerg
- Departments of Clinical Medicine and Endocrinology, Aalborg University and Aalborg University Hospital, Aalborg, Denmark
| | - Lena Bjergved
- Research Centre for Prevention and Health, The Capital Region of Denmark, Glostrup, Denmark
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Inge Bülow Pedersen
- Departments of Clinical Medicine and Endocrinology, Aalborg University and Aalborg University Hospital, Aalborg, Denmark
| | - Allan Carlé
- Departments of Clinical Medicine and Endocrinology, Aalborg University and Aalborg University Hospital, Aalborg, Denmark
- Diagnostic Centre, Region Hospital Silkeborg, Silkeborg, Denmark
| | - Nils Knudsen
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Hans Perrild
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Lars Ovesen
- Department of Gastroenterology, Slagelse Hospital, Slagelse, Denmark
| | - Lone Banke Rasmussen
- Department of Endocrinology, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Peter Laurberg
- Departments of Clinical Medicine and Endocrinology, Aalborg University and Aalborg University Hospital, Aalborg, Denmark
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Affiliation(s)
- Joel Ehrenkranz
- Department of Medicine, Intermountain Medical Center , Murray, Utah
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