1
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Bath SC. Thyroid function and iodine intake: global recommendations and relevant dietary trends. Nat Rev Endocrinol 2024:10.1038/s41574-024-00983-z. [PMID: 38693274 DOI: 10.1038/s41574-024-00983-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/20/2024] [Indexed: 05/03/2024]
Abstract
Iodine is a micronutrient that is essential for thyroid hormone production. Adequate iodine intake is especially important during pregnancy and early life, when brain development is dependent on thyroid hormones. Iodine intake recommendations vary around the world, but most recommendations generally reflect the increased requirements during pregnancy and lactation, although adequate iodine intake before pregnancy is also important. Tremendous progress has been made in improving iodine intake across the world over the past 30 years, mainly through salt-iodization programmes. However, in countries without strong iodine fortification programmes, and with shifts in dietary patterns, a need has arisen for health organizations, governments and clinicians to ensure that adequate iodine is consumed by everyone in the population. For example, in countries in which adequate iodine intake depends on individual food choice, particularly of iodine-rich milk and dairy products, intake can be highly variable and is also vulnerable to changing dietary patterns. In this Review, iodine is considered in the wider context of the increasing prevalence of overweight and obesity, the dietary trends for salt restriction for cardiovascular health and the increasing uptake of plant-based diets.
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Affiliation(s)
- Sarah C Bath
- Department of Nutrition, Food and Exercise Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.
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Lopes CA, Duarte M, Prazeres S, Carvalho I, Vilarinho L, Martinez-de-Oliveira J, Limbert E, Lemos MC. Maternal Urinary Iodine Concentration during Pregnancy and Its Impact on Child Growth and Neurodevelopment: An 11-Year Follow-Up Study. Nutrients 2023; 15:4447. [PMID: 37892522 PMCID: PMC10610250 DOI: 10.3390/nu15204447] [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: 09/30/2023] [Revised: 10/15/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023] Open
Abstract
Mild-to-moderate iodine deficiency during pregnancy is prevalent worldwide, but its consequences for maternal and child health are not clear. We aimed to investigate the impact of maternal iodine intake during pregnancy on the child's growth and neurodevelopment. This study involved a cohort of 11-year-old children (n = 70) whose mothers had participated in an iodine intake survey during pregnancy. Gestational, neonatal, anthropometric, intelligence quotient (IQ), and socioeconomic parameters were analyzed according to maternal urinary iodine concentration (UIC). There was a positive linear trend of current height Z-score, full-scale IQ, verbal IQ, family income, maternal education, and a negative trend of neonatal TSH levels with increasing maternal UIC levels. However, regression analysis indicated that maternal UIC was not an independent predictor of any gestational, neonatal, or childhood development parameter. Only maternal school education was positively associated with child height and IQ. In conclusion, we did not find any evidence of a direct effect of maternal iodine intake during pregnancy on the long-term growth and neurodevelopment of children. The results suggest that socioeconomic factors are important confounding factors that affect both maternal iodine intake and child development and must be considered when investigating the association between maternal iodine intake and child outcomes.
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Affiliation(s)
- Carla A. Lopes
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal; (C.A.L.); (M.D.); (J.M.-d.-O.)
- Departamento da Saúde da Criança e da Mulher, Centro Hospitalar Universitário Cova da Beira, 6200-251 Covilhã, Portugal
| | - Marta Duarte
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal; (C.A.L.); (M.D.); (J.M.-d.-O.)
| | - Susana Prazeres
- Laboratório de Endocrinologia, Serviço de Patologia Clínica, Instituto Português de Oncologia de Lisboa Francisco Gentil, 1099-023 Lisboa, Portugal;
| | - Ivone Carvalho
- Unidade de Rastreio Neonatal, Metabolismo e Genética, Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 4000-055 Porto, Portugal; (I.C.); (L.V.)
| | - Laura Vilarinho
- Unidade de Rastreio Neonatal, Metabolismo e Genética, Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 4000-055 Porto, Portugal; (I.C.); (L.V.)
| | - José Martinez-de-Oliveira
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal; (C.A.L.); (M.D.); (J.M.-d.-O.)
- Departamento da Saúde da Criança e da Mulher, Centro Hospitalar Universitário Cova da Beira, 6200-251 Covilhã, Portugal
| | - Edward Limbert
- Serviço de Endocrinologia, Instituto Português de Oncologia de Lisboa Francisco Gentil, 1099-023 Lisboa, Portugal;
| | - Manuel C. Lemos
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal; (C.A.L.); (M.D.); (J.M.-d.-O.)
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Abstract
Iodine, through the thyroid hormones, is required for the development of the auditory cortex and cochlea (the sensory organ for hearing). Deafness is a well-documented feature of endemic cretinism resulting from severe iodine deficiency. However, the range of effects of suboptimal iodine intake during auditory development on the hearing ability of children is less clear. We therefore aimed to systematically review the evidence for the association between iodine exposure (i.e. intake/status/supplementation) during development (i.e. pregnancy and/or childhood) and hearing outcomes in children. We searched PubMed and Embase and identified 330 studies, of which thirteen were included in this review. Only three of the thirteen studies were of low risk of bias or of good quality, this therefore limited our ability to draw firm conclusions. Nine of the studies (69 %) were in children (one RCT, two non-RCT interventions and six cross-sectional studies) and four (31 %) were in pregnant women (one RCT, one cohort study and two case reports). The RCT of iodine supplementation in mildly iodine-deficient pregnant women found no effect on offspring hearing thresholds. However, hearing was a secondary outcome of the trial and not all women were from an iodine-deficient area. Iodine supplementation of severely iodine-deficient children (in both non-RCT interventions) resulted in improved hearing thresholds. Five of six cross-sectional studies (83 %) found that higher iodine status in children was associated with better hearing. The current evidence base for the association between iodine status and hearing outcomes is limited and further good-quality research on this topic is needed.
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Optimizing Growth: The Case for Iodine. Nutrients 2023; 15:nu15040814. [PMID: 36839172 PMCID: PMC9959690 DOI: 10.3390/nu15040814] [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: 12/30/2022] [Revised: 01/29/2023] [Accepted: 02/03/2023] [Indexed: 02/08/2023] Open
Abstract
Iodine is an essential micronutrient and component of thyroid hormone. An adequate dietary iodine intake is critical to maintain and promote normal growth and development, especially during vulnerable life stages such as pregnancy and early infancy. The role of iodine in cognitive development is supported by numerous interventional and observational studies, and when iodine intake is too low, somatic growth is also impaired. This can be clearly seen in cases of untreated congenital hypothyroidism related to severe iodine deficiency, which is characterized, in part, by a short stature. Nevertheless, the impact of a less severe iodine deficiency on growth, whether in utero or postnatal, is unclear. Robust studies examining the relationship between iodine and growth are rarely feasible, including the aspect of examining the effect of a single micronutrient on a process that is reliant on multiple nutrients for optimal success. Conversely, excessive iodine intake can affect thyroid function and the secretion of optimal thyroid hormone levels; however, whether this affects growth has not been examined. This narrative review outlines the mechanisms by which iodine contributes to the growth process from conception onwards, supported by evidence from human studies. It emphasizes the need for adequate iodine public health policies and their robust monitoring and surveillance, to ensure coverage for all population groups, particularly those at life stages vulnerable for growth. Finally, it summarizes the other micronutrients important to consider alongside iodine when seeking to assess the impact of iodine on somatic growth.
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Cannas A, Rayman MP, Kolokotroni O, Bath SC. Iodine status of pregnant women from the Republic of Cyprus. Br J Nutr 2023; 129:126-134. [PMID: 35236523 PMCID: PMC9816652 DOI: 10.1017/s0007114522000617] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 02/08/2022] [Accepted: 02/18/2022] [Indexed: 01/21/2023]
Abstract
Iodine supply is crucial during pregnancy to ensure that the proper thyroid function of mother and baby support fetal brain development. Little is known about iodine status or its dietary determinants in pregnant women in the Republic of Cyprus. We therefore recruited 128 pregnant women at their first-trimester ultrasound scan to a cross-sectional study. We collected spot-urine samples for the measurement of urinary iodine concentration (UIC, µg/l) and creatinine concentration (Creat, g/l), the latter of which allows us to correct for urine dilution and to compute the iodine-to-creatinine ratio (UI/Creat). Women completed a FFQ and a general questionnaire. We used a General Linear model to explore associations between maternal and dietary characteristics with UI/Creat. The median UIC (105 µg/l) indicated iodine deficiency according to the WHO criterion (threshold for adequacy = 150 µg/l), and the UI/Creat was also low at 107 µg/g. Only 32 % (n 45) of women reported the use of iodine-containing supplements; users had a higher UI/Creat than non-users (131 µg/g v. 118 µg/g), though this difference was NS in the adjusted analysis (P = 0·37). Of the dietary components, only egg intake was significantly associated with a higher UI/Creat in adjusted analyses (P = 0·018); there was no significant association with milk, dairy products or fish intake. Our results suggest that pregnant women in Cyprus have inadequate iodine status and are at risk of mild-to-moderate iodine deficiency. Further research on dietary sources in this population is required.
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Affiliation(s)
- Andrea Cannas
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - Margaret P. Rayman
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - Ourania Kolokotroni
- Department of Primary Care and Population Health, University of Nicosia, Medical School, Nicosia, 1700, Cyprus
| | - Sarah C. Bath
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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Maternal Iodine Status and Birth Outcomes: A Systematic Literature Review and Meta-Analysis. Nutrients 2023; 15:nu15020387. [PMID: 36678261 PMCID: PMC9865661 DOI: 10.3390/nu15020387] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
Background & aims: Iodine is important for thyroid function during pregnancy to support fetal growth, but studies of maternal iodine status and birth outcomes are conflicting. We aimed to quantify the association between iodine status and birth outcomes, including potential threshold effects using nonlinear dose−response curves. Methods: We systematically searched Medline and Embase to 10 October 2022 for relevant cohort studies. We conducted random-effects meta-analyses of urinary iodine concentration (UIC), iodine:creatinine ratio (I:Cr), and iodide intake for associations with birth weight, birth weight centile, small for gestational age (SGA), preterm delivery, and other birth outcomes. Study quality was assessed using the Newcastle-Ottawa scale. Results: Meta-analyses were conducted on 23 cohorts with 42269 participants. Birth weight was similar between UIC ≥ 150 μg/L and <150 μg/L (difference = 30 g, 95% CI −22 to 83, p = 0.3, n = 13, I2 = 89%) with no evidence of linear trend (4 g per 50 μg/L, −3 to 10, p = 0.2, n = 12, I2 = 80%). I:Cr was similar, but with nonlinear trend suggesting I:Cr up to 200 μg/g associated with increasing birthweight (p = 0.02, n = 5). Birthweight was 2.0 centiles (0.3 to 3.7, p = 0.02, n = 4, I2 = 0%) higher with UIC ≥ 150 μg/g, but not for I:Cr. UIC ≥ 150 μg/L was associated with lower risk of SGA (RR = 0.85, 0.75 to 0.96, p = 0.01, n = 13, I2 = 0%), but not with I:Cr. Conclusions: The main risk of bias was adjustment for confounding, with variation in urine sample collection and exposure definition. There were modest-sized associations between some measures of iodine status, birth weight, birth weight centile, and SGA. In pregnancy, we recommend that future studies report standardised measures of birth weight that take account of gestational age, such as birth weight centile and SGA. Whilst associations were modest-sized, we recommend maintaining iodine sufficiency in the population, especially for women of childbearing age on restricted diets low in iodide.
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Pregnant Dutch Women Have Inadequate Iodine Status and Selenium Intake. Nutrients 2022; 14:nu14193936. [PMID: 36235589 PMCID: PMC9572179 DOI: 10.3390/nu14193936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/14/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022] Open
Abstract
Iodine and selenium are essential for thyroid hormone synthesis. Iodine and selenium interact. Pregnancy increases the maternal iodine requirement. We previously reported inadequate iodine status in pregnant Dutch women. Since little is known about their selenium intake, we investigated the iodine status and selenium intake in relation to iodine and selenium supplement use during pregnancy. Iodine status was established in 201 apparently healthy pregnant women as 24 h iodine excretion (24H-UIE; sufficient if median ≥225 µg), iodine concentration (24H-UIC; ≥150 µg/L) and iodine/creatinine ratio (24H-UICR; ≥150 µg/g). Selenium intake was calculated from 24 h selenium excretion. Iodine status in pregnancy proved insufficient (medians: 24H-UIE 185 µg; 24H-UIC 95 µg/L; 24H-UICR 141 µg/g). Only women taking 150 µg iodine/day were sufficient (median 24H-UIE 244 µg). Selenium intake was below the Estimated Average Requirement (EAR; 49 µg/day) in 53.8%, below the Recommended Dietary Allowance (RDA; 60 µg/day) in 77.4% and below the Adequate Intake (AI; 70 µg/day) in 88.7%. Combined inadequate iodine status and selenium intake <RDA was found in 61%. Women who want to become pregnant should, consistently with WHO and ETA recommendations, be advised to use a 150 µg iodine-containing supplement. Concomitant selenium supplementation should be added to this advice, at least in The Netherlands.
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Hisada A, Takatani R, Yamamoto M, Nakaoka H, Sakurai K, Mori C. Maternal Iodine Intake and Neurodevelopment of Offspring: The Japan Environment and Children's Study. Nutrients 2022; 14:nu14091826. [PMID: 35565793 PMCID: PMC9105063 DOI: 10.3390/nu14091826] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/20/2022] [Accepted: 04/24/2022] [Indexed: 02/05/2023] Open
Abstract
Inadequate maternal iodine intake affects thyroid function and may impair fetal brain development. This study investigated the association between maternal iodine intake during pregnancy and neurodevelopmental delay in offspring at 1 and 3 years of age using a nationwide birth cohort: the Japan Environment and Children’s Study. We assessed dietary iodine intake during pregnancy using a food frequency questionnaire and child neurodevelopment using the Japanese translation of the Ages and Stages Questionnaire, Third Edition. The risk of delay (score below the cut-off value) for fine motor domain at 1 year of age was increased in the lowest quintile iodine intake group compared with the fourth quintile iodine intake group. The risk of delay for problem-solving at 1 year of age was increased in the lowest and second quintile iodine intake group and decreased in the highest quintile iodine intake group. The risk of delay for communication, fine motor, problem-solving, and personal–social domains at 3 years of age was increased in the lowest and second quintile iodine intake group compared with the fourth quintile iodine intake group, while the risk of delay for fine motor and problem-solving domains was decreased in the highest quintile iodine intake group. Low iodine intake levels in pregnancy may affect child neurodevelopment.
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Affiliation(s)
- Aya Hisada
- Center for Preventive Medical Sciences, Chiba University, 1–33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; (R.T.); (M.Y.); (H.N.); (K.S.); (C.M.)
- Correspondence: ; Tel.: +81-4-3290-3896
| | - Rieko Takatani
- Center for Preventive Medical Sciences, Chiba University, 1–33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; (R.T.); (M.Y.); (H.N.); (K.S.); (C.M.)
| | - Midori Yamamoto
- Center for Preventive Medical Sciences, Chiba University, 1–33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; (R.T.); (M.Y.); (H.N.); (K.S.); (C.M.)
| | - Hiroko Nakaoka
- Center for Preventive Medical Sciences, Chiba University, 1–33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; (R.T.); (M.Y.); (H.N.); (K.S.); (C.M.)
| | - Kenichi Sakurai
- Center for Preventive Medical Sciences, Chiba University, 1–33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; (R.T.); (M.Y.); (H.N.); (K.S.); (C.M.)
| | - Chisato Mori
- Center for Preventive Medical Sciences, Chiba University, 1–33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; (R.T.); (M.Y.); (H.N.); (K.S.); (C.M.)
- Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
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Calcaterra V, Mameli C, Rossi V, Massini G, Gambino M, Baldassarre P, Zuccotti G. The Iodine Rush: Over- or Under-Iodination Risk in the Prophylactic Use of Iodine for Thyroid Blocking in the Event of a Nuclear Disaster. Front Endocrinol (Lausanne) 2022; 13:901620. [PMID: 35692388 PMCID: PMC9178126 DOI: 10.3389/fendo.2022.901620] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 04/22/2022] [Indexed: 11/13/2022] Open
Abstract
Iodine is an essential element for the production of thyroid hormones (THs). Both deficient and excess iodine intakes may precipitate in adverse thyroidal events. Radioactive iodine (RI) is a common byproduct of nuclear fission processes. During nuclear emergencies RI may be released in a plume, or cloud, contaminating the environment. If inhaled or ingested, it may lead to internal radiation exposure and the uptake of RI mainly by the thyroid gland that absorbs stable iodine (SI) and RI in the same way. A dose of radiation delivered to the thyroid gland is a main risk factor for the thyroid cancer development. The SI prophylaxis helps prevent childhood thyroid cancer. The thyroid gland saturation with prophylactic SI ingestion, reduces the internal exposure of the thyroid by blocking the uptake of RI and inhibiting iodide organification. However, negative impact of inadequate SI intake must be considered. We provide an overview on the recommended iodine intake and the impact of SI and RI on thyroid in children and adolescents, discussing the benefits and adverse effects of the prophylactic SI for thyroid blocking during a nuclear accident. The use of SI for protection against RI may be recommended in cases of radiological or nuclear emergencies, moreover the administration of iodine for prophylactic purposes should be cautious. Benefits and risks should also be considered according to age. Adverse effects from iodine administration cannot be excluded. Precise indications are mandatory to use the iodine for thyroid blocking. Due to this natural adaption mechanism it's possible to tolerate large doses of iodine without clinical effects, however, a prolonged assumption of the iodine when not needed can be dangerous and may precipitate in severe thyroidal and non-thyroidal negative effects.
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Affiliation(s)
- Valeria Calcaterra
- Pediatric Department, “Vittore Buzzi” Children’s Hospital, Milan, Italy
- Pediatric and Adolescent Unit, Department of Internal Medicine, University of Pavia, Pavia, Italy
- *Correspondence: Valeria Calcaterra,
| | - Chiara Mameli
- Pediatric Department, “Vittore Buzzi” Children’s Hospital, Milan, Italy
- Department of Biomedical and Clinical Sciences “L. Sacco”, University of Milan, Milan, Italy
| | - Virginia Rossi
- Pediatric Department, “Vittore Buzzi” Children’s Hospital, Milan, Italy
| | - Giulia Massini
- Pediatric Department, “Vittore Buzzi” Children’s Hospital, Milan, Italy
| | - Mirko Gambino
- Pediatric Department, “Vittore Buzzi” Children’s Hospital, Milan, Italy
| | - Paola Baldassarre
- Pediatric Department, “Vittore Buzzi” Children’s Hospital, Milan, Italy
| | - Gianvincenzo Zuccotti
- Pediatric Department, “Vittore Buzzi” Children’s Hospital, Milan, Italy
- Department of Biomedical and Clinical Sciences “L. Sacco”, University of Milan, Milan, Italy
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Verkaik-Kloosterman J. Neonatal heel prick screening TSH concentration in the Netherlands as indicator of iodine status. Nutr J 2021; 20:63. [PMID: 34218798 PMCID: PMC8256570 DOI: 10.1186/s12937-021-00722-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 06/19/2021] [Indexed: 12/02/2022] Open
Abstract
Background Neonatal Thyroid Stimulating Hormone (nTSH) is proposed as indicator of iodine deficiency in a population. Population’s iodine sufficiency is indicated by a proportion of the newborns less than 3% having nTSH above 5 mIU/L. The aim of this study was to explore the Dutch neonatal heel prick screening TSH data to assess iodine status in the Netherlands and identify determinants and potential confounders of this assessment. Methods All newborns born in the Netherlands between 2007 and 2015 with a heel prick collection at day 3-7 were included (n = 1,435,600), except preterm neonates and baby’s with a low birth weight. Total T4 was measured for all children, nTSH was measured in the ~ 20% children with lowest total T4. Results The proportion with nTSH > 5mIU/L fluctuated between 0.6-1.3% in 2007-2015. nTSH was significantly associated with laboratory performing the nTSH assay and age of heel prick sampling. The overall increasing trend in proportion nTSH >1mIU/L was confounded by the laboratories with different and changed assays. Conclusions The low proportion neonates with high nTSH suggests a sufficient iodine status in the Netherlands. Whether the increased proportion nTSH>1mIU/L over the years is an early indicator of deterioration of the iodine status remains unclear, due to differences and changes in analytical assays. nTSH might be a valuable and inexpensive way to get crude insight in the (trend in) iodine status, but more research is needed on the validity and potential conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s12937-021-00722-4.
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Affiliation(s)
- Janneke Verkaik-Kloosterman
- National Institute for Public Health and the Environment (RIVM), PO box 1, 3720, Bilthoven, BA, The Netherlands.
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Nazeri P, Tahmasebinejad Z, Pearce EN, Zarezadeh Z, Tajeddini T, Mirmiran P, Azizi F. Does maternal iodine supplementation during the lactation have a positive impact on neurodevelopment of children? Three-year follow up of a randomized controlled trial. Eur J Nutr 2021; 60:4083-4091. [PMID: 33974129 DOI: 10.1007/s00394-021-02574-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/27/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE The aim of this study was to examine, for the first time, the neurodevelopmental outcomes in children whose mothers received different doses of iodine supplements during lactation. METHODS We conducted a follow-up study on children whose mothers participated in a randomized clinical trial to receive placebo, 150 µg/day or 300 µg/day of iodine until 12 months postpartum. Child neurocognitive development was assessed at 36 months of age using the Bayley Scales of Infant and Toddler Development Third Edition. Linear mixed-model analysis was preformed to assess iodine supplement dose effects on child cognitive, language, and motor functions. RESULTS A total of 122 children provided neurodevelopmental data as follows: 300 µg/d iodine group: 45; 150 µg/d iodine group: 35; and placebo group: 42. Cognitive scores were higher in children whose mothers received 150 µg iodine/d compared to children whose mothers received placebo [102.8 (SD 13.2) vs. 99.2 (SD 10.5); β = 4.43, P = 0.032]. However, supplementation with 150 µg iodine/d had no effect on language or motor development. No significant differences were observed in cognitive, language, or motor functions between children whose mothers received 300 µg iodine/d and those whose mothers received 150 µg iodine/d or placebo. CONCLUSION Maternal iodine supplementation with 150 µg/d during lactation may have a beneficial effect on child cognitive development; however, we found no evidence of either improved or delayed neurodevelopmental outcomes in children whose mothers received iodine supplements at doses higher than recommended. Further randomized controlled trials with larger sample sizes are needed to confirm these results. CLINICAL TRIAL REGISTRY IRCT201303164794N8; registration date: 2013-05-20.
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Affiliation(s)
- Pantea Nazeri
- Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Zhale Tahmasebinejad
- Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box: 19395-4763, Tehran, Iran
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, USA
| | - Zinat Zarezadeh
- Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Tahere Tajeddini
- Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Parvin Mirmiran
- Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box: 19395-4763, Tehran, Iran. .,Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, P.O. Box: 19395-4763, Tehran, Iran.
| | - Fereidoun Azizi
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box: 19395-4763, Tehran, Iran.
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Woodside JV, Mullan KR. Iodine status in UK-An accidental public health triumph gone sour. Clin Endocrinol (Oxf) 2021; 94:692-699. [PMID: 33249610 DOI: 10.1111/cen.14368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/16/2020] [Accepted: 10/27/2020] [Indexed: 11/30/2022]
Abstract
The improvement in iodine status among the UK population from the 1930s onwards has been described as an 'accidental public health triumph' despite the lack of any iodine fortification program. However, iodine deficiency in the UK has re-emerged in vulnerable groups and is likely due to a combination of changing farming practices, dietary preferences and public health priorities. The UK is now among only a minority of European countries with no legislative framework for iodine fortification. The experience of folic acid fortification and the 28-year delay in its implementation lays bare the political difficulties of introducing any fortification program in the UK. If iodine fortification is not an imminent possibility, then it is important to explore other options: how to change farming practice especially on organic farms; encourage dairy intake; protect and expand our public health programs of milk provision for vulnerable groups and embark on education programs for women of childbearing potential and healthcare professionals. This review explores how the UK may have arrived at this juncture and how the iodine status of the nation may be improved at this time of major political and public health upheaval.
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Affiliation(s)
- Jayne V Woodside
- School of Medicine, Dentistry and Biomedical Sciences, Institute for Global Food Security, Centre for Public Health, Queen's University Belfast, Belfast, UK
| | - Karen R Mullan
- Regional Centre for Endocrinology and Diabetes, Royal Victoria Hospital, BHSCT, Belfast, UK
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Threapleton DE, Snart CJP, Keeble C, Waterman AH, Taylor E, Mason D, Reid S, Azad R, Hill LJB, Meadows S, McKillion A, Alwan NA, Cade JE, Simpson NAB, Stewart PM, Zimmermann M, Wright J, Waiblinger D, Mon-Williams M, Hardie LJ, Greenwood DC. Maternal iodine status in a multi-ethnic UK birth cohort: Associations with child cognitive and educational development. Paediatr Perinat Epidemiol 2021; 35:236-246. [PMID: 32870514 DOI: 10.1111/ppe.12719] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 07/17/2020] [Accepted: 07/28/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Maternal iodine requirements increase during pregnancy to supply thyroid hormones critical for fetal neurodevelopment. Iodine insufficiency may result in poorer cognitive or child educational outcomes but current evidence is sparse and inconsistent. OBJECTIVES To quantify the association between maternal iodine status and child educational outcomes. METHODS Urinary iodine concentrations (UIC) and iodine/creatinine ratios (I:Cr) were measured in 6971 mothers at 26-28 weeks' gestation participating in the Born in Bradford cohort. Maternal iodine status was examined in relation to child school achievement (early years foundation stage (EYFS), phonics, and Key Stage 1 (KS1)), other learning outcomes, social and behavioural difficulties, and sensorimotor control in 5745 children aged 4-7 years. RESULTS Median (interquartile range) UIC was 76 µg/L (46, 120), and I:Cr was 83 µg/g (59, 121). Overall, there was no strong or consistent evidence to support associations between UIC or I:Cr and neurodevelopmental outcomes. For instance, predicted EYFS and phonics scores (primary outcomes) at the 25th vs 75th I:Cr percentiles (99% confidence intervals) were similar, with no evidence of associations: EYFS scores were 32 (99% CI 31, 33) and 33 (99% CI 32, 34), and phonics scores were 34 (99% CI 33, 35) and 35 (99% CI 34, 36), respectively. CONCLUSIONS In the largest single study of its kind, there was little evidence of detrimental neurodevelopmental outcomes in children born to pregnant women with iodine insufficiency as defined by World Health Organization-outlined thresholds. Alternative functional biomarkers for iodine status in pregnancy and focused assessment of other health outcomes may provide additional insight.
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Affiliation(s)
- Diane E Threapleton
- Leeds Institute of Cardiovascular & Metabolic Medicine, School of Medicine, University of Leeds, Leeds, UK
| | - Charles J P Snart
- Leeds Institute of Cardiovascular & Metabolic Medicine, School of Medicine, University of Leeds, Leeds, UK
| | - Claire Keeble
- Leeds Institute of Cardiovascular & Metabolic Medicine, School of Medicine, University of Leeds, Leeds, UK.,Leeds Institute for Data Analytics, University of Leeds, Leeds, UK
| | | | - Elizabeth Taylor
- Leeds Institute of Cardiovascular & Metabolic Medicine, School of Medicine, University of Leeds, Leeds, UK
| | - Dan Mason
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK
| | - Stephen Reid
- Earth Surface Science Institute, School of Earth and Environment, University of Leeds, Leeds, UK
| | - Rafaq Azad
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK
| | - Liam J B Hill
- School of Psychology, University of Leeds, Leeds, UK
| | - Sarah Meadows
- Elsie Widdowson Laboratory, University of Cambridge, Cambridge, UK.,NIHR Nutritional Biomarker Laboratory, MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Amanda McKillion
- Elsie Widdowson Laboratory, University of Cambridge, Cambridge, UK.,NIHR Nutritional Biomarker Laboratory, MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Nisreen A Alwan
- Faculty of Medicine, School of Primary Care and Population Sciences, Southampton General Hospital, University of Southampton, Southampton, UK.,NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Janet E Cade
- Nutritional Epidemiology Group, School of Food Science & Nutrition, University of Leeds, Leeds, UK
| | - Nigel A B Simpson
- Division of Women's and Children's Health, School of Medicine, University of Leeds, Leeds, UK
| | - Paul M Stewart
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Michael Zimmermann
- Laboratory for Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zürich, Switzerland
| | - John Wright
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK
| | - Dagmar Waiblinger
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK
| | | | - Laura J Hardie
- Leeds Institute of Cardiovascular & Metabolic Medicine, School of Medicine, University of Leeds, Leeds, UK
| | - Darren C Greenwood
- Leeds Institute of Cardiovascular & Metabolic Medicine, School of Medicine, University of Leeds, Leeds, UK.,Leeds Institute for Data Analytics, University of Leeds, Leeds, UK
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Guo F, Liu Y, Ding Z, Zhang C, Liu Z, Fan J. Supplemental iodine-containing prenatal multivitamins use and the potential effects on pregnancy outcomes in a mildly iodine-deficient region. J Endocrinol Invest 2021; 44:443-452. [PMID: 32514901 DOI: 10.1007/s40618-020-01321-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/01/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE The use and contribution of prenatal multivitamins (PMV) as iodine source for pregnant women in China, especially in mildly iodine-deficient region, have not been well studied. This study aimed to explore the association between PMV intake during pregnancy and thyroid function in mothers and newborns. METHODS We performed a study involving women with a history of taking PMV during pregnancy between January 2013 and October 2015, in Shanghai, a mildly iodine-deficient region. Maternal thyroid function in early and late pregnancy, and neonatal TSH on postnatal d 3 were obtained from medical records. We compared the outcomes in pregnant women who took exclusively iodine-containing PMV (I + PMV) with those who took exclusively non-contained PMV (I- PMV). Propensity score matching (PSM) was used to identify women with similar baseline characteristics. RESULTS After PSM, 1280 women in I + PMV and 2560 in I- PMV had similar propensity scores and were included in the analyses. Introduction of I + PMV to women was associated with slightly higher maternal thyroid hormone production (higher maternal FT4, p = 0.01, non-significantly lower TSH, p = 0.79) and lower neonatal TSH levels (p < 0.0001). The frequency of adverse pregnancy outcomes or thyroid dysfunctions did not differ between groups in late pregnancy. Mothers received I + PMV (0.2 SD) had a stronger association of maternal TSH with neonatal TSH than those who received I- PMV (0.1 SD). These effects were only shown in TPOAb-negative mothers, not in TPOAb-positive mothers. CONCLUSION TPOAb-positive women display an impaired iodine transport in thyroid and placenta, and this may explain the lack of changes in maternal and neonatal thyroid parameters with I + PMV supplementation in these women. This phenomenon might suggest that these women require different iodine doses or treatment approach in comparison with TPOAb-negative women.
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Affiliation(s)
- F Guo
- Obstetrical Department, School of Medicine, The International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University, 910 Hengshan Rd, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
| | - Y Liu
- Obstetrical Department, School of Medicine, The International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University, 910 Hengshan Rd, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
| | - Z Ding
- Obstetrical Department, School of Medicine, The International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University, 910 Hengshan Rd, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
| | - C Zhang
- Obstetrical Department, School of Medicine, The International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University, 910 Hengshan Rd, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
| | - Z Liu
- Obstetrical Department, School of Medicine, The International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University, 910 Hengshan Rd, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
| | - J Fan
- Obstetrical Department, School of Medicine, The International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University, 910 Hengshan Rd, Shanghai, China.
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China.
- Shanghai Municipal Key Clinical Specialty, Shanghai, China.
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15
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Kerver JM, Pearce EN, Ma T, Gentchev M, Elliott MR, Paneth N. Prevalence of inadequate and excessive iodine intake in a US pregnancy cohort. Am J Obstet Gynecol 2021; 224:82.e1-82.e8. [PMID: 32653458 PMCID: PMC7779669 DOI: 10.1016/j.ajog.2020.06.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/04/2020] [Accepted: 06/29/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND US iodine intake, estimated from the median urinary iodine concentration of population representative data, has declined by half since the 1970s, which is problematic because maternal iodine intake is critical for fetal neurodevelopment. Relying on median urinary concentrations to assess iodine intake of populations is standard practice but does not describe the number of individuals with insufficient intake. Prevalence estimates of inadequate and excessive intake are better for informing public health applications but require multiple urine samples per person; such estimates have been generated in pediatric populations but not yet among pregnant women. OBJECTIVE Our aims were as follows: (1) to assess median urinary iodine concentrations across pregnancy for comparison with national data and (2) to estimate the prevalence of inadequate and excessive iodine intake among pregnant women in mid-Michigan. STUDY DESIGN Data were collected from 2008 to 2015 as part of a prospective pregnancy cohort in which women were enrolled at their first prenatal clinic visit. Few exclusion criteria (<18 years or non-English speaking) resulted in a sample of women generally representative of the local community, unselected for any specific health conditions. Urine specimens were obtained as close as practicable to at least 1 specimen per trimester during routine prenatal care throughout pregnancy (n=1-6 specimens per woman) and stored at -80°C until urinary iodine was measured to estimate the iodine intake (n=1014 specimens from 464 women). We assessed urinary iodine across pregnancy by each gestational week of pregnancy and by trimester. We used multiple urine specimens per woman, accounted for within-person variability, performed data transformation to approximate normality, and estimated the prevalence of inadequate and excessive iodine intake using a method commonly employed for assessment of nutrient status. RESULTS Maternal characteristics reflected the local population in racial and ethnic diversity and socioeconomic status as follows: 53% non-Hispanic white, 22% non-Hispanic black, and 16% Hispanic; 48% had less than or equal to high school education and 71% had an annual income of <$25,000. Median urinary iodine concentrations in the first, second, and third trimester-including some women contributing more than 1 specimen per trimester-were 171 μg/L (n=305 specimens), 181 μg/L (n=366 specimens), and 179 μg/L (n=343 specimens), respectively, with no significant difference by trimester (P=.50, Kruskal-Wallis test for equality of medians). The estimated prevalence of inadequate and excessive iodine intake was 23% and <1%, respectively. CONCLUSION Median urinary iodine concentrations in each trimester were above the World Health Organization cutoff of 150 μg/L, indicating iodine sufficiency at the group level across pregnancy. However, the estimated prevalence of inadequate iodine intake was substantial at 23%, whereas prevalence of excessive intake was <1%, indicating a need for at least some women to increase consumption of iodine during pregnancy. The American Thyroid Association, the Endocrine Society, and the American Academy of Pediatrics recommend that all pregnant and lactating women receive a daily multivitamin or mineral supplement that contains 150 μg of iodine. The data presented here should encourage the collection of similar data from additional US population samples for the purpose of informing the American College of Obstetricians and Gynecologists' own potential recommendations for prenatal iodine supplementation.
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Affiliation(s)
- Jean M Kerver
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI; Department of Pediatrics and Human Development, Michigan State University, East Lansing, MI.
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes, Nutrition and Weight Management, Department of Medicine, Boston University School of Medicine, Boston, MA
| | - Tengfei Ma
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI
| | - Monica Gentchev
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI
| | - Michael R Elliott
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI
| | - Nigel Paneth
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI; Department of Pediatrics and Human Development, Michigan State University, East Lansing, MI
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16
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Farias PM, Marcelino G, Santana LF, de Almeida EB, Guimarães RDCA, Pott A, Hiane PA, Freitas KDC. Minerals in Pregnancy and Their Impact on Child Growth and Development. Molecules 2020; 25:molecules25235630. [PMID: 33265961 PMCID: PMC7730771 DOI: 10.3390/molecules25235630] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/15/2020] [Accepted: 10/21/2020] [Indexed: 12/11/2022] Open
Abstract
During pregnancy, women undergo metabolic and physiological changes, and their needs are higher, to maintain growth and development of the fetus. If the nutritional status of the expectant mother is not satisfactory, some maternal and neonatal complications can occur. In the second and third trimester of pregnancy, there is a reserve of nutrients in the fetus that can be utilized after birth; thereby, children present an accelerated growth in the first years of life, which is a proven response to the available nutrition pattern. However, if such a pattern is insufficient, there will be deficits during development, including brain function. Therefore, despite many recent published works about gestational nutrition, uncertainties still remain on the mechanisms of absorption, distribution, and excretion of micronutrients. Further elucidation is needed to better understand the impacts caused either by deficiency or excess of some micronutrients. Thus, to illustrate the contributions of minerals during prenatal development and in children, iodine, selenium, iron, zinc, calcium, and magnesium were selected. Our study sought to review the consequences related to gestational deficiency of the referred minerals and their impact on growth and development in children born from mothers with such deficiencies
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Affiliation(s)
- Patricia Miranda Farias
- Graduate Program in Health and Development in the Central-West Region of Brazil, Medical School, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil; (P.M.F.); (G.M.); (L.F.S.); (R.d.C.A.G.); (P.A.H.)
| | - Gabriela Marcelino
- Graduate Program in Health and Development in the Central-West Region of Brazil, Medical School, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil; (P.M.F.); (G.M.); (L.F.S.); (R.d.C.A.G.); (P.A.H.)
| | - Lidiani Figueiredo Santana
- Graduate Program in Health and Development in the Central-West Region of Brazil, Medical School, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil; (P.M.F.); (G.M.); (L.F.S.); (R.d.C.A.G.); (P.A.H.)
| | - Eliane Borges de Almeida
- Biologist, Hematology Laboratory, State Secretariat of Health of Mato Grosso do Sul, Campo Grande 79084-180, Mato Grosso do Sul, Brazil;
| | - Rita de Cássia Avellaneda Guimarães
- Graduate Program in Health and Development in the Central-West Region of Brazil, Medical School, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil; (P.M.F.); (G.M.); (L.F.S.); (R.d.C.A.G.); (P.A.H.)
| | - Arnildo Pott
- Graduate Program in Biotechnology and Biodiversity in the Central-West Region of Brazil, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil;
| | - Priscila Aiko Hiane
- Graduate Program in Health and Development in the Central-West Region of Brazil, Medical School, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil; (P.M.F.); (G.M.); (L.F.S.); (R.d.C.A.G.); (P.A.H.)
| | - Karine de Cássia Freitas
- Graduate Program in Health and Development in the Central-West Region of Brazil, Medical School, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil; (P.M.F.); (G.M.); (L.F.S.); (R.d.C.A.G.); (P.A.H.)
- Correspondence: ; Tel.: +55-67-3345-7416
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17
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Korobitsyna R, Aksenov A, Sorokina T, Trofimova A, Sobolev N, Grjibovski AM, Chashchin V, Thomassen Y. Iodine Status of Women and Infants in Russia: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E8346. [PMID: 33187335 PMCID: PMC7697687 DOI: 10.3390/ijerph17228346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 12/13/2022]
Abstract
This systematic review presents a critical synthesis of the available information on the iodine status among women and infants in Russia. Literature search was performed in accordance with PRISMA guidelines using PubMed, Scopus Web of Science databases as well as eLIBRARY-the Russian national source. Altogether, 277 papers were identified and 19 of them were eligible for the review. The data on median urinary iodine concentration (UIC) in women and infants from 25 Russian regions were presented. A substantial variability in UIC across the country with no clear geographical pattern was observed. Despite substantial heterogeneity in research methodology and data presentation the results suggest that the iodine status among pregnant women and infants in Russia is below the recommended levels. Our findings demonstrate that iodine deficiency is a re-emerging public health problem in Russia. Urgent public health measures on national, regional and individual levels are warranted.
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Affiliation(s)
- Rimma Korobitsyna
- Arctic Biomonitoring Laboratory, Northern (Arctic) Federal University Named After M. V. Lomonosov, Naberezhnaya Severnoy Dvini 17, 163002 Arkhangelsk, Russia; (A.A.); (T.S.); (A.T.); (N.S.); (Y.T.)
| | - Andrey Aksenov
- Arctic Biomonitoring Laboratory, Northern (Arctic) Federal University Named After M. V. Lomonosov, Naberezhnaya Severnoy Dvini 17, 163002 Arkhangelsk, Russia; (A.A.); (T.S.); (A.T.); (N.S.); (Y.T.)
| | - Tatiana Sorokina
- Arctic Biomonitoring Laboratory, Northern (Arctic) Federal University Named After M. V. Lomonosov, Naberezhnaya Severnoy Dvini 17, 163002 Arkhangelsk, Russia; (A.A.); (T.S.); (A.T.); (N.S.); (Y.T.)
| | - Anna Trofimova
- Arctic Biomonitoring Laboratory, Northern (Arctic) Federal University Named After M. V. Lomonosov, Naberezhnaya Severnoy Dvini 17, 163002 Arkhangelsk, Russia; (A.A.); (T.S.); (A.T.); (N.S.); (Y.T.)
| | - Nikita Sobolev
- Arctic Biomonitoring Laboratory, Northern (Arctic) Federal University Named After M. V. Lomonosov, Naberezhnaya Severnoy Dvini 17, 163002 Arkhangelsk, Russia; (A.A.); (T.S.); (A.T.); (N.S.); (Y.T.)
| | - Andrej M Grjibovski
- Central Scientific Research Laboratory, Northern State Medical University of the Ministry of Healthcare of the Russian Federation, Troitskiy Ave. 51, 163000 Arkhangelsk, Russia;
- Department of Health Policy and Management, Al-Farabi Kazakh National University, Almay 050040, Kazakhstan
- Department of Epidemiology and Modern Vaccination Technologies, Sechenov First Moscow State Medical University (Sechenov University), 119991 Moscow, Russia
- West Kazakhstan Marat Ospanov Medical University, Aktobe 0300190, Kazakhstan
| | - Valery Chashchin
- North-Western State Medical University named after I.I. Mechnikov, Kirochnaya ul. 41, 191015 Saint-Petersburg, Russia;
- Institute of Ecology, National Research University Higher School of Economics, Myasnitskaya str. 20, 101000 Moscow, Russia
| | - Yngvar Thomassen
- Arctic Biomonitoring Laboratory, Northern (Arctic) Federal University Named After M. V. Lomonosov, Naberezhnaya Severnoy Dvini 17, 163002 Arkhangelsk, Russia; (A.A.); (T.S.); (A.T.); (N.S.); (Y.T.)
- Institute of Ecology, National Research University Higher School of Economics, Myasnitskaya str. 20, 101000 Moscow, Russia
- National Institute of Occupational Health, P.O. Box 5330 Majorstua, N-0304 Oslo, Norway
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18
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Asfaw A, Belachew T. <p>Effect of Iodine Deficiency on Academic Performance of School Children in Dawro Zone, Southwest Ethiopia: A Prospective Cohort Study</p>. NUTRITION AND DIETARY SUPPLEMENTS 2020. [DOI: 10.2147/nds.s259104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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19
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Dineva M, Fishpool H, Rayman MP, Mendis J, Bath SC. Systematic review and meta-analysis of the effects of iodine supplementation on thyroid function and child neurodevelopment in mildly-to-moderately iodine-deficient pregnant women. Am J Clin Nutr 2020; 112:389-412. [PMID: 32320029 DOI: 10.1093/ajcn/nqaa071] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/18/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Mild-to-moderate iodine deficiency, particularly in pregnancy, is prevalent; this is of concern because observational studies have shown negative associations with child neurodevelopment. Although neither the benefits nor the safety of iodine supplementation in pregnancy in areas of mild-to-moderate deficiency are well researched, such supplementation is increasingly being recommended by health authorities in a number of countries. OBJECTIVES By reviewing the most recent published data on the effects of iodine supplementation in mildly-to-moderately deficient pregnant women on maternal and infant thyroid function and child cognition, we aimed to determine whether the evidence was sufficient to support recommendations in these areas. METHODS A systematic review of randomized controlled trials (RCTs), non-RCT interventions, and observational studies was conducted. To identify relevant articles, we searched the PubMed and Embase databases. We defined mild-to-moderate iodine deficiency as a baseline median urinary iodine concentration (UIC) of 50-149 µg/L. Eligible studies were included in meta-analyses. RESULTS In total, 37 publications were included-10 RCTs, 4 non-RCT interventions, and 23 observational studies. Most studies showed no effect of iodine supplementation on maternal or infant thyroid-stimulating hormone and free thyroxine. Most RCTs found that supplementation reduced maternal thyroglobulin and in 3 RCTs, it prevented or diminished the increase in maternal thyroid volume during pregnancy. Three RCTs addressed child neurodevelopment; only 1 was adequately powered. Meta-analyses of 2 RCTs showed no effect on child cognitive [mean difference (MD): -0.18; 95% CI: -1.22, 0.87], language (MD: 1.28; 95% CI: -0.28, 2.83), or motor scores (MD: 0.28; 95% CI: -1.10, 1.66). CONCLUSIONS There is insufficient good-quality evidence to support current recommendations for iodine supplementation in pregnancy in areas of mild-to-moderate deficiency. Well-designed RCTs, with child cognitive outcomes, are needed in pregnant women who are moderately deficient (median UIC < 100 µg/L). Maternal intrathyroidal iodine stores should be considered in future trials by including appropriate measures of preconceptional iodine intake.This review was registered at www.crd.york.ac.uk/prospero as CRD42018100277.
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Affiliation(s)
- Mariana Dineva
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Harry Fishpool
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Margaret P Rayman
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Jeewaka Mendis
- Surrey Clinical Trials Unit, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Sarah C Bath
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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20
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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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21
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Levie D, Bath SC, Guxens M, Korevaar TIM, Dineva M, Fano E, Ibarluzea JM, Llop S, Murcia M, Rayman MP, Sunyer J, Peeters RP, Tiemeier H. Maternal Iodine Status During Pregnancy Is Not Consistently Associated with Attention-Deficit Hyperactivity Disorder or Autistic Traits in Children. J Nutr 2020; 150:1516-1528. [PMID: 32171006 PMCID: PMC7269752 DOI: 10.1093/jn/nxaa051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/19/2019] [Accepted: 02/13/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Severe iodine deficiency during pregnancy can cause intellectual disability, presumably through inadequate placental transfer of maternal thyroid hormone to the fetus. The association between mild-to-moderate iodine deficiency and child neurodevelopmental problems is not well understood. OBJECTIVES We investigated the association of maternal iodine status during pregnancy with child attention-deficit hyperactivity disorder (ADHD) and autistic traits. METHODS This was a collaborative study of 3 population-based birth cohorts: Generation R (n = 1634), INfancia y Medio Ambiente (n = 1293), and the Avon Longitudinal Study of Parents and Children (n = 2619). Exclusion criteria were multiple fetuses, fertility treatment, thyroid-interfering medication use, and pre-existing thyroid disease. The mean age of assessment in the cohorts was between 4.4 and 7.7 y for ADHD symptoms and 4.5 and 7.6 y for autistic traits. We studied the association of the urinary iodine-to-creatinine ratio (UI/Creat) <150 μg/g-in all mother-child pairs, and in those with a urinary-iodine measurement at ≤18 weeks and ≤14 weeks of gestation-with the risk of ADHD or a high autistic-trait score (≥93rd percentile cutoff), using logistic regression. The cohort-specific effect estimates were combined by random-effects meta-analyses. We also investigated whether UI/Creat modified the associations of maternal free thyroxine (FT4) or thyroid-stimulating hormone concentrations with ADHD or autistic traits. RESULTS UI/Creat <150 μg/g was not associated with ADHD (OR: 1.2; 95% CI: 0.7, 2.2; P = 0.56) or with a high autistic-trait score (OR: 0.8; 95% CI: 0.6, 1.1; P = 0.22). UI/Creat <150 μg/g in early pregnancy (i.e., ≤18 weeks or ≤14 weeks of gestation) was not associated with a higher risk of behavioral problems. The association between a higher FT4 and a greater risk of ADHD (OR: 1.3; 95% CI: 1.0, 1.6; P = 0.017) was not modified by iodine status. CONCLUSIONS There is no consistent evidence to support an association of mild-to-moderate iodine deficiency during pregnancy with child ADHD or autistic traits.
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Affiliation(s)
- Deborah Levie
- The Generation R Study Group, Erasmus University Medical Centre, Rotterdam, Netherlands,Department of Internal Medicine, Academic Center For Thyroid Diseases, Erasmus University Medical Centre, Rotterdam, Netherlands,Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre–Sophia Children's Hospital, Rotterdam, Netherlands,ISGlobal, Barcelona, Spain,Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona, Spain,Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Carlos III Health Institute, Madrid, Spain
| | - Sarah C Bath
- Department of Nutritional Sciences, University of Surrey, Guildford, United Kingdom
| | - Mònica Guxens
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre–Sophia Children's Hospital, Rotterdam, Netherlands,ISGlobal, Barcelona, Spain,Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona, Spain,Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Carlos III Health Institute, Madrid, Spain
| | - Tim I M Korevaar
- The Generation R Study Group, Erasmus University Medical Centre, Rotterdam, Netherlands,Department of Internal Medicine, Academic Center For Thyroid Diseases, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Mariana Dineva
- Department of Nutritional Sciences, University of Surrey, Guildford, United Kingdom
| | - Eduardo Fano
- BIODONOSTIA, Health Research Institute, Donostia—San Sebastián, Spain,Faculty of Psychology, University of the Basque Country (UPV/EHU), Donostia—San Sebastián, Spain
| | - Jesús M Ibarluzea
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Carlos III Health Institute, Madrid, Spain,BIODONOSTIA, Health Research Institute, Donostia—San Sebastián, Spain,Faculty of Psychology, University of the Basque Country (UPV/EHU), Donostia—San Sebastián, Spain,Basque Government Department of Health, Deputy Directorate of Public Health of Gipuzkoa, Donostia—San Sebastián, Spain
| | - Sabrina Llop
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Carlos III Health Institute, Madrid, Spain,Epidemiology and Environmental Health Joint Research Unit, FISABIO–Jaume I University–University of València, Valencia, Spain
| | - Mario Murcia
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Carlos III Health Institute, Madrid, Spain,Epidemiology and Environmental Health Joint Research Unit, FISABIO–Jaume I University–University of València, Valencia, Spain
| | - Margaret P Rayman
- Department of Nutritional Sciences, University of Surrey, Guildford, United Kingdom
| | - Jordi Sunyer
- ISGlobal, Barcelona, Spain,Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona, Spain,Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Carlos III Health Institute, Madrid, Spain,Hospital del Mar Research Institute (IMIM), Barcelona, Spain
| | - Robin P Peeters
- Department of Internal Medicine, Academic Center For Thyroid Diseases, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Henning Tiemeier
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre–Sophia Children's Hospital, Rotterdam, Netherlands,Department of Social and Behavioral Science, Harvard TH Chan School of Public Health, Boston, MA, USA,Address correspondence to HT (e-mail: )
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Dineva M, Rayman MP, Levie D, Guxens M, Peeters RP, Vioque J, González L, Espada M, Ibarluzea J, Sunyer J, Korevaar TIM, Bath SC. Similarities and differences of dietary and other determinants of iodine status in pregnant women from three European birth cohorts. Eur J Nutr 2020; 59:371-387. [PMID: 30734058 DOI: 10.1007/s00394-019-01913-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/23/2019] [Indexed: 12/31/2022]
Abstract
PURPOSE As a component of thyroid hormones, adequate iodine intake is essential during pregnancy for fetal neurodevelopment. Across Europe, iodine deficiency is common in pregnancy, but data are lacking on the predictors of iodine status at this life stage. We, therefore, aimed to explore determinants of iodine status during pregnancy in three European populations of differing iodine status. METHODS Data were from 6566 pregnant women from three prospective population-based birth cohorts from the United Kingdom (ALSPAC, n = 2852), Spain (INMA, n = 1460), and The Netherlands (Generation R, n = 2254). Urinary iodine-to-creatinine ratio (UI/Creat, µg/g) was measured in spot-urine samples in pregnancy (≤ 18-weeks gestation). Maternal dietary intake, categorised by food groups (g/day), was estimated from food-frequency questionnaires (FFQs). Multivariable regression models used dietary variables (energy-adjusted) and maternal characteristics as predictors of iodine status. RESULTS Median UI/Creat in pregnant women of ALSPAC, INMA, and Generation R was 121, 151, and 210 µg/g, respectively. Maternal age was positively associated with UI/Creat in all cohorts (P < 0.001), while UI/Creat varied by ethnicity only in Generation R (P < 0.05). Of the dietary predictors, intake of milk and dairy products (per 100 g/day) was positively associated with UI/Creat in all cohorts [ALSPAC (B = 3.73, P < 0.0001); INMA (B = 6.92, P = 0.002); Generation R (B = 2.34, P = 0.001)]. Cohort-specific dietary determinants positively associated with UI/Creat included fish and shellfish in ALSPAC and INMA, and eggs and cereal/cereal products in Generation R. CONCLUSIONS The cohort-specific dietary determinants probably reflect not only dietary habits but iodine-fortification policies; hence, public-health interventions to improve iodine intake in pregnancy need to be country-specific.
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Affiliation(s)
- Mariana Dineva
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK
| | - Margaret P Rayman
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK
| | - Deborah Levie
- The Generation R Study Group, Erasmus University Medical Centre, Rotterdam, The Netherlands
- Department of Internal Medicine, Academic Centre for Thyroid Diseases, Erasmus University Medical Centre, Rotterdam, The Netherlands
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre-Sophia Children's Hospital, Rotterdam, The Netherlands
- ISGlobal, Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain
| | - Mònica Guxens
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre-Sophia Children's Hospital, Rotterdam, The Netherlands
- ISGlobal, Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain
| | - Robin P Peeters
- Department of Internal Medicine, Academic Centre for Thyroid Diseases, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Jesus Vioque
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain
- Nutritional Epidemiology Unit, Miguel Hernández University, ISABIAL-FISABIO, Alicante, Spain
| | - Llúcia González
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
- Predepartamental Unit of Medicine, University Jaume I, Castelló, Spain
| | - Mercedes Espada
- Departamento de Salud del Gobierno Vasco, Public Health Laboratory of Bilbao, Basque Government, Derio, Spain
- BIODONOSTIA Health Research Institute, Donostia-San Sebastián, Spain
| | - Jesús Ibarluzea
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain
- BIODONOSTIA Health Research Institute, Donostia-San Sebastián, Spain
- Departamento de Salud del Gobierno Vasco, Subdirección de Salud Pública de Guipúzcoa, Donostia-San Sebastián, Spain
- Facultad de Psicología, University of the Basque Country UPV/EHU, Donostia-San Sebastián, Spain
| | - Jordi Sunyer
- ISGlobal, Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
| | - Tim I M Korevaar
- The Generation R Study Group, Erasmus University Medical Centre, Rotterdam, The Netherlands
- Department of Internal Medicine, Academic Centre for Thyroid Diseases, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Sarah C Bath
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK.
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23
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Levie D, Korevaar TIM, Bath SC, Murcia M, Dineva M, Llop S, Espada M, van Herwaarden AE, de Rijke YB, Ibarluzea JM, Sunyer J, Tiemeier H, Rayman MP, Guxens M, Peeters RP. Association of Maternal Iodine Status With Child IQ: A Meta-Analysis of Individual Participant Data. J Clin Endocrinol Metab 2019; 104:5957-5967. [PMID: 30920622 PMCID: PMC6804415 DOI: 10.1210/jc.2018-02559] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/22/2019] [Indexed: 12/16/2022]
Abstract
CONTEXT Although the consequences of severe iodine deficiency are beyond doubt, the effects of mild to moderate iodine deficiency in pregnancy on child neurodevelopment are less well established. OBJECTIVE To study the association between maternal iodine status during pregnancy and child IQ and identify vulnerable time windows of exposure to suboptimal iodine availability. DESIGN Meta-analysis of individual participant data from three prospective population-based birth cohorts: Generation R (Netherlands), INMA (Spain), and ALSPAC (United Kingdom); pregnant women were enrolled between 2002 and 2006, 2003 and 2008, and 1990 and 1992, respectively. SETTING General community. PARTICIPANTS 6180 mother-child pairs with measures of urinary iodine and creatinine concentrations in pregnancy and child IQ. Exclusion criteria were multiple pregnancies, fertility treatment, medication affecting the thyroid, and preexisting thyroid disease. MAIN OUTCOME MEASURE Child nonverbal and verbal IQ assessed at 1.5 to 8 years of age. RESULTS There was a positive curvilinear association of urinary iodine/creatinine ratio (UI/Creat) with mean verbal IQ only. UI/Creat <150 µg/g was not associated with lower nonverbal IQ (-0.6 point; 95% CI: -1.7 to 0.4 points; P = 0.246) or lower verbal IQ (-0.6 point; 95% CI: -1.3 to 0.1 points; P = 0.082). Stratified analyses showed that the association of UI/Creat with verbal IQ was only present up to 14 weeks of gestation. CONCLUSIONS Fetal brain development is vulnerable to mild to moderate iodine deficiency, particularly in the first trimester. Our results show that potential randomized controlled trials investigating the effect of iodine supplementation in women with mild to moderate iodine deficiency on child neurodevelopment should begin supplementation not later than the first trimester.
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Affiliation(s)
- Deborah Levie
- The Generation R Study Group, Erasmus University Medical Centre, CA Rotterdam, Netherlands
- Department of Internal Medicine, Academic Center For Thyroid Diseases, Erasmus University Medical Centre, CA Rotterdam, Netherlands
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre–Sophia Children’s Hospital, CB Rotterdam, Netherlands
- ISGlobal, Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Spanish Consortium for Research on Epidemiology and Public Health, Instituto de Salud Carlos III, Madrid, Spain
| | - Tim I M Korevaar
- The Generation R Study Group, Erasmus University Medical Centre, CA Rotterdam, Netherlands
- Department of Internal Medicine, Academic Center For Thyroid Diseases, Erasmus University Medical Centre, CA Rotterdam, Netherlands
| | - Sarah C Bath
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Mario Murcia
- Spanish Consortium for Research on Epidemiology and Public Health, Instituto de Salud Carlos III, Madrid, Spain
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Mariana Dineva
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Sabrina Llop
- Spanish Consortium for Research on Epidemiology and Public Health, Instituto de Salud Carlos III, Madrid, Spain
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Mercedes Espada
- Spanish Consortium for Research on Epidemiology and Public Health, Instituto de Salud Carlos III, Madrid, Spain
- Clinical Chemistry Unit, Public Health Laboratory of Bilbao, Basque Government, Parque Tecnológico de Bizkaia, Derio, Spain
| | - Antonius E van Herwaarden
- Department of Laboratory Medicine, Radboud University Nijmegen Medical Centre, GA Nijmegen, Netherlands
| | - Yolanda B de Rijke
- Department of Internal Medicine, Academic Center For Thyroid Diseases, Erasmus University Medical Centre, CA Rotterdam, Netherlands
- Department of Clinical Chemistry, Erasmus University Medical Centre, CN Rotterdam, Netherlands
| | - Jesús M Ibarluzea
- Spanish Consortium for Research on Epidemiology and Public Health, Instituto de Salud Carlos III, Madrid, Spain
- Departamento de Sanidad Gobierno Vasco, Subdirección de Salud Pública de Guipúzcoa, Donostia – San Sebastián, Spain
- BIODONOSTIA Health Research Institute, Donostia – San Sebastián, Spain
- Faculty of Psychology, University of the Basque Country UPV/EHU, Donostia – San Sebastián, Spain
| | - Jordi Sunyer
- ISGlobal, Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Spanish Consortium for Research on Epidemiology and Public Health, Instituto de Salud Carlos III, Madrid, Spain
- Hospital del Mar Research Institute, Barcelona, Spain
| | - Henning Tiemeier
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre–Sophia Children’s Hospital, CB Rotterdam, Netherlands
- Department of Social and Behavioral Science, Harvard TH Chan School of Public Health, Boston, Massachusetts
| | - Margaret P Rayman
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Mònica Guxens
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre–Sophia Children’s Hospital, CB Rotterdam, Netherlands
- ISGlobal, Barcelona, Spain
- Pompeu Fabra University, Barcelona, Spain
- Spanish Consortium for Research on Epidemiology and Public Health, Instituto de Salud Carlos III, Madrid, Spain
| | - Robin P Peeters
- Department of Internal Medicine, Academic Center For Thyroid Diseases, Erasmus University Medical Centre, CA Rotterdam, Netherlands
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24
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Eastman CJ, Ma G, Li M. Optimal Assessment and Quantification of Iodine Nutrition in Pregnancy and Lactation: Laboratory and Clinical Methods, Controversies and Future Directions. Nutrients 2019; 11:E2378. [PMID: 31590373 PMCID: PMC6835375 DOI: 10.3390/nu11102378] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/05/2019] [Accepted: 09/15/2019] [Indexed: 11/16/2022] Open
Abstract
Iodine intake must be boosted during pregnancy to meet the demands for increased production and placental transfer of thyroid hormone essential for optimal foetal development. Failure to meet this challenge results in irreversible brain damage, manifested in severity from neurological cretinism to minor or subtle deficits of intelligence and behavioural disorders. Attention is now being focused on explaining observational studies of an association between insufficient iodine intake during pregnancy and mild degrees of intellectual impairment in the offspring and confirming a cause and effect relationship with impaired maternal thyroid function. The current qualitative categorisation of iodine deficiency into mild, moderate and severe by the measurement of the median urinary iodine concentration (MUIC) in a population of school-age children, as a proxy measure of dietary iodine intake, is inappropriate for defining the degree or severity of gestational iodine deficiency and needs to be replaced. This review examines progress in analytical techniques for the measurement of urinary iodine concentration and the application of this technology to epidemiological studies of iodine deficiency with a focus on gestational iodine deficiency. We recommend that more precise definitions and measurements of gestational iodine deficiency, beyond a spot UIC, need to be developed. We review the evidence for hypothyroxinaemia as the cause of intrauterine foetal brain damage in gestational iodine deficiency and discuss the many unanswered questions, from which we propose that further clinical studies need to be designed to address the pathogenesis of neurodevelopmental impairments in the foetus and infant. Agreement on the testing instruments and standardization of processes and procedures for Intelligence Quotient (IQ) and psychomotor tests needs to be reached by investigators, so that valid comparisons can be made among studies of gestational iodine deficiency and neurocognitive outcomes. Finally, the timing, safety and the efficacy of prophylactic iodine supplementation for pregnant and lactating women needs to be established and confirmation that excess intake of iodine during pregnancy is to be avoided.
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Affiliation(s)
- Creswell J Eastman
- Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney 2006, Australia.
- Australian Centre for Control of Iodine Deficiency Disorders (ACCIDD), Faculty of Medicine and Health, The University of Sydney, Sydney 2006, Australia.
| | - Gary Ma
- Australian Centre for Control of Iodine Deficiency Disorders (ACCIDD), Faculty of Medicine and Health, The University of Sydney, Sydney 2006, Australia.
- School of Medicine (Pathology), Liverpool Hospital Clinical School, Western Sydney University, Liverpool, Sydney 2170, Australia.
| | - Mu Li
- Australian Centre for Control of Iodine Deficiency Disorders (ACCIDD), Faculty of Medicine and Health, The University of Sydney, Sydney 2006, Australia.
- School of Public Health, Faculty of Medicine and Health, The University of Sydney, Sydney 2006, Australia.
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25
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Hay I, Hynes KL, Burgess JR. Mild-to-Moderate Gestational Iodine Deficiency Processing Disorder. Nutrients 2019; 11:E1974. [PMID: 31443337 PMCID: PMC6770179 DOI: 10.3390/nu11091974] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/12/2019] [Accepted: 08/15/2019] [Indexed: 12/28/2022] Open
Abstract
This synopsis paper aims to identify if a common pattern of learning and social difficulties can be conceptualized across recent longitudinal studies investigating the influence of mild-to-moderate gestational iodine deficiency (GID) on offspring's optimal cognitive and psycho-social development. The main studies investigated are: The Southampton Women's Study (SWS)-United Kingdom; the Avon Longitudinal Study of Parents and Children (ALSPAC)-United Kingdom; the Gestational Iodine Cohort Longitudinal Study-Tasmania, Australia, and the Danish National Birth Cohort Case-Control Study-Denmark. In contrast to severe GID where there is a global negative impact on neurodevelopment, mild-to-moderate intrauterine iodine deficiency has subtler, but nonetheless important, permanent cognitive and psycho-social consequences on the offspring. This paper links the results from each study and maintains that mild-to-moderate GID is associated with a disorder that is characterized by speed of neural transmitting difficulties that are typically associated with working memory capacity difficulties and attention and response inhibition. The authors maintain that this disorder is better identified as Gestational Iodine Deficiency Processing Disorder (GIDPD), rather than, what to date has often been identified as 'suboptimal development'. The Autistic Spectrum Disorder (ASD), Attention Deficit, Hyperactivity Disorder (ADHD), language and literacy disorders (learning disabilities and dyslexia) are the main manifestations associated with GIDPD. GIDPD is identified on IQ measures, but selectively and mainly on verbal reasoning IQ subtests, with individuals with GIDPD still operating within the 'normal' full-scale IQ range. Greater consideration needs to be given by public health professionals, policy makers and educators about the important and preventable consequences of GID. Specifically, more emphasis should be placed on adequate iodine intake in women prior to pregnancy, as well as during pregnancy and when lactating. Secondly, researchers and others need to further extend, refine and clarify whether GIDPD, as a nosological (medical classification) entity, is a valid disorder and concept for consideration.
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Affiliation(s)
- Ian Hay
- Faculty of Education, University of Tasmania, Launceston 7250, Australia.
| | - Kristen L Hynes
- Menzies Institute for Medical Research, University of Tasmania, Hobart 7001, Australia
| | - John R Burgess
- Department of Endocrinology, Royal Hobart Hospital, Hobart 7001, Australia
- School of Medicine, University of Tasmania, Hobart 7000, Australia
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26
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Hynes KL, Otahal P, Burgess JR, Oddy WH, Hay I. Correction: Hynes et al. "Reduced Educational Outcomes Persist into Adolescence Following Mild Iodine Deficiency in Utero, Despite Adequacy in Childhood: 15-Year Follow-Up of the Gestational Iodine Cohort Investigating Auditory Processing Speed and Working Memory" Nutrients 2017, 9 (12), 1354. Nutrients 2019; 11:nu11061272. [PMID: 31195606 PMCID: PMC6628325 DOI: 10.3390/nu11061272] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 04/10/2019] [Indexed: 11/16/2022] Open
Affiliation(s)
- Kristen L Hynes
- Menzies Institute for Medical Research, University of Tasmania, Private Bag 23, Hobart, TAS 7001, Australia.
| | - Petr Otahal
- Menzies Institute for Medical Research, University of Tasmania, Private Bag 23, Hobart, TAS 7001, Australia.
| | - John R Burgess
- Department of Endocrinology, Royal Hobart Hospital, 48 Liverpool Street, Hobart, TAS 7000, Australia.
- School of Medicine, University of Tasmania, 17 Liverpool Street, Hobart, TAS 7000, Australia.
| | - Wendy H Oddy
- Menzies Institute for Medical Research, University of Tasmania, Private Bag 23, Hobart, TAS 7001, Australia.
| | - Ian Hay
- Faculty of Education, University of Tasmania, Locked Bag 1307, Launceston, TAS 7250, Australia.
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27
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Magri F, Zerbini F, Gaiti M, Capelli V, Croce L, Bini S, Rigamonti AE, Fiorini G, Cella SG, Chiovato L. Poverty and immigration as a barrier to iodine intake and maternal adherence to iodine supplementation. J Endocrinol Invest 2019; 42:435-442. [PMID: 30132288 DOI: 10.1007/s40618-018-0938-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/06/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE Iodine deficiency still remains a significant health issue worldwide. Pregnant and lactating women are at risk for iodine deficiency when living in mild iodine-deficient areas such as Italy. This study aims at evaluating the consumption of iodized salt, iodine-rich-foods and maternal micronutrient supplements in a group of women with limited access to the Italian National Health System. METHODS A cross-sectional survey was conducted among immigrant and Italian women living in poverty and referring to 40 Non-Governmental Organization throughout Italy for their health needs. 3483 women answered the ad hoc questionnaire between January 2017 and February 2018. RESULTS The consumption of iodized salt was very low, and even lower among immigrant women. Determinants of iodized salt consumption were the period spent in Italy for immigrant women and living in a family-type setting, parity and, particularly, the degree of education for Italian ones. 17.5% of immigrant women and 8.6% of the Italian ones reported a diagnosis of thyroid disease. 521 women, 75.4% of whom were immigrants, were pregnant or breast-feeding. The majority (57.3%) had no specific maternal supplementation. CONCLUSIONS Both Italian and immigrating women with a low income or without access to the public health system have a poor adherence both to the salt iodization policy and to folic acid and iodine supplements in preconception and pregnancy. They also referred a low-frequency intake of iodine-rich-foods. The identification of barriers to health care access could be useful to promote specific health interventions in this target population.
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Affiliation(s)
- F Magri
- Unit of Internal Medicine and Endocrinology, ICS Maugeri I.R.C.C.S, University of Pavia, Via S. Maugeri 10, 27100, Pavia, Italy
| | - F Zerbini
- Unit of Internal Medicine and Endocrinology, ICS Maugeri I.R.C.C.S, University of Pavia, Via S. Maugeri 10, 27100, Pavia, Italy
| | - M Gaiti
- Unit of Internal Medicine and Endocrinology, ICS Maugeri I.R.C.C.S, University of Pavia, Via S. Maugeri 10, 27100, Pavia, Italy
| | - V Capelli
- Unit of Internal Medicine and Endocrinology, ICS Maugeri I.R.C.C.S, University of Pavia, Via S. Maugeri 10, 27100, Pavia, Italy
| | - L Croce
- Unit of Internal Medicine and Endocrinology, ICS Maugeri I.R.C.C.S, University of Pavia, Via S. Maugeri 10, 27100, Pavia, Italy
| | - S Bini
- Department of Clinical Sciences and Community Health, University of Milan, Via Vanvitelli, 32, 20129, Milan, Italy
| | - A E Rigamonti
- Department of Clinical Sciences and Community Health, University of Milan, Via Vanvitelli, 32, 20129, Milan, Italy
| | - G Fiorini
- Istituti Clinici Zucchi, Carate, Italy
| | - S G Cella
- Department of Clinical Sciences and Community Health, University of Milan, Via Vanvitelli, 32, 20129, Milan, Italy
| | - L Chiovato
- Unit of Internal Medicine and Endocrinology, ICS Maugeri I.R.C.C.S, University of Pavia, Via S. Maugeri 10, 27100, Pavia, Italy.
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Heidari Z, Arefhosseini SR, Hedayati M, Vaghef-Mehrabany E, Ebrahimi-Mameghani M. Iodine status, and knowledge about iodine deficiency disorders in adolescent school girls aged 14-19 years, 2016. Health Promot Perspect 2019; 9:77-84. [PMID: 30788271 PMCID: PMC6377704 DOI: 10.15171/hpp.2019.10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 12/01/2018] [Indexed: 12/18/2022] Open
Abstract
Background: Adequate iodine intake by women in child-bearing age affects fetus neurodevelopment during pregnancy. A majority of previous studies has investigated iodine status among children, and there is limited data on female adolescents who are more exposed to consequences of iodine deficiency (ID) in their near-future pregnancies; thus, we aimed to assess iodine status, and knowledge on iodine deficiency disorders (IDDs) among adolescent school girls (14-19 years old) in Shahriar, Iran. Methods: This cross-sectional study was conducted among 223 female students selected through multi-stage cluster sampling from 12 schools. Iodine and creatinine concentrations were measured in casual urine samples. Iodine content of household salts was also assessed.Data on intake of salt and iodine-rich food sources were collected applying a food frequency questionnaire (FFQ), and knowledge about iodine and IDDs were assessed by a questionnaire. Results: Median and Mean (95% CI) concentrations of urinary iodine and creatinine were 129 µg/L, 137.62 µg/L (95% CI: 126.28, 148.95) and 1.72 g/L, 1.86 g/L (95% CI: 0.55-3.17),respectively. The frequency of mild, moderate and severe ID were 22.4%, 14.3% and 0%,respectively; 43.5% had adequate, and 3.1% had excessive urinary iodine levels. Mean saltiodine concentration was 21.69 (SD=10.56) ppm. Mean knowledge score was 12.7 (SD=3.44).About half of the students had a poor (25.1%) or fair (24.2%) knowledge about iodine deficiency.Adjusting for the confounders, no significant positive association was found between knowledge about iodine-rich food sources and goitrogens with urinary iodine excretion. Conclusion: Adolescent girls in Shahriar had relatively poor knowledge of iodine, and about one third of them suffered from ID.
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Affiliation(s)
- Zahra Heidari
- Student Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Mehdi Hedayati
- Cellular and Molecular Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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29
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Women Remain at Risk of Iodine Deficiency during Pregnancy: The Importance of Iodine Supplementation before Conception and Throughout Gestation. Nutrients 2019; 11:nu11010172. [PMID: 30650544 PMCID: PMC6356319 DOI: 10.3390/nu11010172] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/22/2018] [Accepted: 01/01/2019] [Indexed: 12/17/2022] Open
Abstract
In Australia, pregnant women are advised to take an iodine supplement (I-supp) (150 µg/day) to reduce risks to the foetus associated with iodine deficiency (ID). To examine the impact of this recommendation on iodine status, and to identify factors that contribute to adequacy during gestation, supplement use and Urinary Iodine Concentration (UIC) was measured in 255 pregnant women (gestation range 6 to 41 weeks) in Tasmania. The median UIC (MUIC) of 133 µg/L (Inter-quartile range 82–233) was indicative of ID, being below the 150–249 µg/L range for adequacy during pregnancy. Women taking an iodine-containing-supplement (I-supp) had a significantly higher MUIC (155 µg/L) (n = 171) compared to the combined MUIC (112.5 µg/L) (n = 84) of those who had never (120 µg/L) (n = 61) or were no longer taking an I-supp (90 µg/L) (n = 23) (p = 0.017). Among women reporting I-supp use, the MUIC of those commencing the recommended 150 µg/day prior to conception was significantly higher than those starting supplementation following pregnancy confirmation: 196 (98–315) µg/L (n = 45) versus 137.5 (82.5–233.5) µg/L (n = 124), p = 0.032. Despite recommendations for iodine supplementation pregnant Tasmanian women remain at risk of ID. Commencing an I-supp of 150 µg/day prior to conception and continuing throughout pregnancy is required to ensure adequacy. Timely advice regarding the importance of adequate iodine nutrition, including supplementation is needed to reduce the risk of irreversible in utero neurocognitive damage to the foetus.
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Abel MH, Brandlistuen RE, Caspersen IH, Aase H, Torheim LE, Meltzer HM, Brantsaeter AL. Language delay and poorer school performance in children of mothers with inadequate iodine intake in pregnancy: results from follow-up at 8 years in the Norwegian Mother and Child Cohort Study. Eur J Nutr 2018; 58:3047-3058. [PMID: 30417257 PMCID: PMC6842354 DOI: 10.1007/s00394-018-1850-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 10/29/2018] [Indexed: 11/25/2022]
Abstract
Purpose Some studies indicate that mild-to-moderate iodine deficiency in pregnant women might negatively affect offspring neurocognitive development, including previous results from the Norwegian Mother and Child Cohort study (MoBa) exploring maternally reported child development at age 3 years. The aim of this follow-up study was to investigate whether maternal iodine intake in pregnancy is associated with language and learning at 8 years of age. Methods The study sample includes 39,471 mother–child pairs participating in MoBa with available information from a validated food frequency questionnaire covering the first half of pregnancy and a questionnaire on child neurocognitive development at 8 years. Multivariable regression was used to explore associations of iodine intake from food and supplements with maternally reported child outcomes. Results Maternal iodine intake from food less than ~ 150 µg/day was associated with poorer child language skills (p-overall = 0.013), reading skills (p-overall = 0.019), and writing skills (p-overall = 0.004) as well as poorer school test result in reading (p < 0.001), and increased likelihood of the child receiving special educational services (p-overall = 0.042) (in non-iodine supplement users). Although significant, differences were generally small. Maternal use of iodine supplements in pregnancy was not significantly associated with any of the outcomes. Conclusions Low habitual iodine intake in pregnant women, i.e., lower than the recommended intake for non-pregnant women, was associated with mothers reporting poorer child language, school performance, and increased likelihood of special educational services. We found no indications of benefits or harm of using iodine-containing supplements in pregnancy. Initiating use in pregnancy might be too late. Electronic supplementary material The online version of this article (10.1007/s00394-018-1850-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marianne H Abel
- Division of Infection Control and Environmental Health, Department of Exposure and Environmental Epidemiology, Norwegian Institute of Public Health, Skøyen, P.O. Box 222, 0213, Oslo, Norway
- Department of Nursing and Health Promotion, Faculty of Health Sciences, Oslo Metropolitan University, St. Olavs plass, P.O. Box 4, 0130, Oslo, Norway
- Department of Nutrition, Tine, SA, P.O. Box 25, 0051, Oslo, Norway
| | - Ragnhild E Brandlistuen
- Division of Mental and Physical Health, Norwegian Institute of Public Health, Skøyen, P.O. Box 222, 0213, Oslo, Norway
| | - Ida H Caspersen
- Division of Infection Control and Environmental Health, Department of Exposure and Environmental Epidemiology, Norwegian Institute of Public Health, Skøyen, P.O. Box 222, 0213, Oslo, Norway
| | - Heidi Aase
- Division of Mental and Physical Health, Norwegian Institute of Public Health, Skøyen, P.O. Box 222, 0213, Oslo, Norway
| | - Liv E Torheim
- Department of Nursing and Health Promotion, Faculty of Health Sciences, Oslo Metropolitan University, St. Olavs plass, P.O. Box 4, 0130, Oslo, Norway
| | - Helle Margrete Meltzer
- Division of Infection Control and Environmental Health, Department of Exposure and Environmental Epidemiology, Norwegian Institute of Public Health, Skøyen, P.O. Box 222, 0213, Oslo, Norway
| | - Anne Lise Brantsaeter
- Division of Infection Control and Environmental Health, Department of Exposure and Environmental Epidemiology, Norwegian Institute of Public Health, Skøyen, P.O. Box 222, 0213, Oslo, Norway.
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Nazeri P, Tahmasebinejad Z, Mehrabi Y, Hedayati M, Mirmiran P, Azizi F. Lactating Mothers and Infants Residing in an Area with an Effective Salt Iodization Program Have No Need for Iodine Supplements: Results from a Double-Blind, Placebo-Controlled, Randomized Controlled Trial. Thyroid 2018; 28:1547-1558. [PMID: 30272528 DOI: 10.1089/thy.2018.0153] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND The necessity of iodine supplementation in lactating mothers residing in countries with sustained salt iodization programs for iodine sufficiency of breast-fed infants remains unclear. The aims of this study were to investigate the effect of iodine supplementation on iodine status and growth parameters of lactating mothers and breast-fed infants and to compare these data with that of formula-feeding mothers and their infants during the first year of infancy. METHODS In this multicenter, double-blinded, randomized clinical trial conducted in four healthcare centers in Tehran (Iran), healthy lactating mothers and their term newborns aged 3-5 days were randomly assigned to treatment groups: placebo, 150 μg/day iodine, or 300 μg/day iodine. They were followed up for 12 months. Formula-fed infants aged 30-45 days and their mothers were randomly selected from the same centers. The primary outcomes were maternal and infant urinary iodine concentrations (UICs), breast-milk iodine concentrations (BMICs), and infant growth parameters, measured at 1, 2, 4, 6, 9, and 12 months during routine health visits. The formula-fed group was assessed at 2, 4, 6, 9, and 12 months of age. Analysis was by per protocol principle using mixed-effects models. RESULTS Mother-newborn pairs (n = 180) in treatment groups and partially/exclusively formula-feeding mother-infant pairs (n = 60) participated between October 2014 and January 2016. Median baseline UICs in the treatment groups were 84 μg/L (interquartile range [IQR] 41-143 μg/L) in mothers and 208 μg/L (IQR 91-310 μg/L) in their infants. The values in the formula-fed group were 76 μg/L (IQR 40-144 μg/L) in mothers and 121 μg/L (IQR 66-243 μg/L) in infants. The 300 μg/day iodine group showed significantly higher UICs and BMICs than did the other treatment groups; infant UICs in the 150 μg/day iodine, placebo, and formula-fed groups were similar. Infants in all groups showed iodine sufficiency (median UIC ≥100 μg/L) throughout the study period. Anthropometric measurements were similar between the treatment and formula-fed groups over the study period, except at the last follow-up visit at 12 months. CONCLUSION Supplementation of breast-feeding mothers with either 300 or 150 μg/day iodine improved their iodine status. However, the iodine status of infants in all groups studied indicated iodine sufficiency during the first year of infancy, demonstrating that in countries with effective salt iodization program, iodine supplementation for lactating mothers is unnecessary.
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Affiliation(s)
- Pantea Nazeri
- 1 Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences , Tehran, Iran
- 2 Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Zhale Tahmasebinejad
- 2 Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Yadollah Mehrabi
- 3 Department of Epidemiology, School of Public Health, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Mehdi Hedayati
- 4 Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Parvin Mirmiran
- 2 Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Fereidoun Azizi
- 5 Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran, Iran
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Abel MH, Korevaar TI, Erlund I, Villanger GD, Caspersen IH, Arohonka P, Alexander J, Meltzer HM, Brantsæter AL. Iodine Intake is Associated with Thyroid Function in Mild to Moderately Iodine Deficient Pregnant Women. Thyroid 2018; 28:1359-1371. [PMID: 30132420 PMCID: PMC6157349 DOI: 10.1089/thy.2018.0305] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Studies indicate that mild to moderate iodine deficiency in pregnancy may have a long-term negative impact on child neurodevelopment. These effects are likely mediated via changes in maternal thyroid function, since iodine is essential for the production of thyroid hormones. However, the impact of iodine availability on thyroid function during pregnancy and on thyroid function reference ranges are understudied. The aim of this study was to investigate the association between iodine intake and thyroid function during pregnancy. DESIGN In a population-based pregnancy cohort including 2910 pregnant women participating in The Norwegian Mother and Child Cohort Study, we explored cross sectional associations of maternal iodine intake measured (1) by a food frequency questionnaire and (2) as iodine concentration in a spot urine sample, with plasma thyroid hormones and antibodies. RESULTS Biological samples were collected in mean gestational week 18.5 (standard deviation 1.3) and diet was assessed in gestational week 22. Median iodine intake from food was 121 μg/day (interquartile range 90, 160), and 40% reported use of iodine-containing supplements in pregnancy. Median urinary iodine concentration (UIC) was 59 μg/L among those who did not use supplements and 98 μg/L in the women reporting current use at the time of sampling, indicating mild to moderate iodine deficiency in both groups. Iodine intake as measured by the food frequency questionnaire was not associated with the outcome measures, while UIC was inversely associated with FT3 (p = 0.002) and FT4 (p < 0.001). Introduction of an iodine-containing supplement after gestational week 12 was associated with indications of lower thyroid hormone production (lower FT4, p = 0.027, and nonsignificantly lower FT3, p = 0.17). The 2.5th and 97.5th percentiles of TSH, FT4, and FT3 were not significantly different by groups defined by calculated iodine intake or by UIC. CONCLUSION The results indicate that mild to moderate iodine deficiency affect thyroid function in pregnancy. However, the differences were small, suggesting that normal reference ranges can be determined based on data also from mildly iodine deficient populations, but this needs to be further studied. Introducing an iodine-containing supplement might temporarily inhibit thyroid hormone production and/or release.
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Affiliation(s)
- Marianne Hope Abel
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Nursing and Health Promotion, Faculty of Health Sciences, OsloMet - Oslo Metropolitan University, Oslo, Norway
- Department of Nutrition, Tine SA, Oslo, Norway
| | - Tim I.M. Korevaar
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
- Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Iris Erlund
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Gro Dehli Villanger
- Division of Mental and Physical Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Ida Henriette Caspersen
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Petra Arohonka
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Jan Alexander
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Helle Margrete Meltzer
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Anne Lise Brantsæter
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
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Maternal Iodine Status is Associated with Offspring Language Skills in Infancy and Toddlerhood. Nutrients 2018; 10:nu10091270. [PMID: 30205599 PMCID: PMC6163597 DOI: 10.3390/nu10091270] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/03/2018] [Accepted: 09/06/2018] [Indexed: 01/01/2023] Open
Abstract
Inadequate iodine status affects the synthesis of the thyroid hormones and may impair brain development in fetal life. The aim of this study was to explore the association between maternal iodine status in pregnancy measured by urinary iodine concentration (UIC) and child neurodevelopment at age 6, 12 and 18 months in a population-based cohort. In total, 1036 families from nine locations in Norway were enrolled in the little in Norway cohort. The present study includes n = 851 mother-child pairs with singleton pregnancies, no use of thyroid medication in pregnancy, no severe genetic disorder, data on exposure (UIC) in pregnancy and developmental outcomes (Bayley Scales of Infant and Toddler Development, third edition). Data collection also included general information from questionnaires. We examined associations between UIC (and use of iodine-containing supplements) and repeated measures of developmental outcomes using multivariable mixed models. The median UIC in pregnancy was 78 µg/L (IQR 46⁻130), classified as insufficient iodine intake according to the WHO. Eighteen percent reported use of iodine-containing multisupplements. A UIC below ~100 was associated with reduced receptive (p = 0.025) and expressive language skills (p = 0.002), but not with reduced cognitive or fine- and gross motor skills. Maternal use of iodine-containing supplements was associated with lower gross motor skills (b = -0.18, 95% CI = -0.33, -0.03, p = 0.02), but not with the other outcome measures. In conclusion, an insufficient iodine intake in pregnancy, reflected in a UIC below ~100 µg/L, was associated with lower infant language skills up to 18 months. The use of iodine-containing supplements was not associated with beneficial effects.
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Iodine Deficiency in a Study Population of Norwegian Pregnant Women-Results from the Little in Norway Study (LiN). Nutrients 2018; 10:nu10040513. [PMID: 29677112 PMCID: PMC5946298 DOI: 10.3390/nu10040513] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/14/2018] [Accepted: 04/18/2018] [Indexed: 11/17/2022] Open
Abstract
Iodine sufficiency is particularly important in pregnancy, where median urinary iodine concentration (UIC) in the range of 150⁻250 µg/L indicates adequate iodine status. The aims of this study were to determine UIC and assess if dietary and maternal characteristics influence the iodine status in pregnant Norwegian women. The study comprises a cross-sectional population-based prospective cohort of pregnant women (Little in Norway (LiN)). Median UIC in 954 urine samples was 85 µg/L and 78.4% of the samples (n = 748) were ≤150 µg/L. 23.2% (n = 221) of the samples were ≤50 µg/L and 5.2% (n = 50) were above the requirements of iodine intake (>250 µg/L). Frequent iodine-supplement users (n = 144) had significantly higher UIC (120 µg/L) than non-frequent users (75 µg/L). Frequent milk and dairy product consumers (4⁻9 portions/day) had significantly higher UIC (99 µg/L) than women consuming 0⁻1 portion/day (57 µg/L) or 2⁻3 portions/day (83 µg/L). Women living in mid-Norway (n = 255) had lowest UIC (72 µg/L). In conclusion, this study shows that the diet of the pregnant women did not necessarily secure a sufficient iodine intake. There is an urgent need for public health strategies to secure adequate iodine nutrition among pregnant women in Norway.
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Iodine as Essential Nutrient during the First 1000 Days of Life. Nutrients 2018; 10:nu10030290. [PMID: 29494508 PMCID: PMC5872708 DOI: 10.3390/nu10030290] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 02/22/2018] [Accepted: 02/27/2018] [Indexed: 12/21/2022] Open
Abstract
Iodine is an essential micronutrient incorporated into thyroid hormones. Although iodine deficiency can lead to a broad spectrum of disorders throughout life, it is most critical in the early stages of development, as the foetal brain is extremely dependent on iodine supply. During the last two decades, our understanding of thyroid physiology during gestation has substantially improved. Furthermore, thyroid hormone receptors have been identified and characterised in placental and embryonic tissues, allowing us to elucidate the maternal-foetal transfer of thyroid hormones. Experimental studies have demonstrated that the cyto-architecture of the cerebral cortex can be irreversibly disturbed in iodine deficiency causing abnormal neuron migratory patterns which are associated with cognitive impairment in children. In this context, the role of iodine as key factor in the programming of foetal and infant neurodevelopment, needs to be revisited with a special focus on areas of mild to moderate iodine deficiency. The objective of this review is to summarize the available evidence from both animals and human studies, for the effect of iodine deficiency (particularly, of maternal hypothyroxinemia) on brain development and neurological or behavioural disorders, such as lower intelligence quotient (IQ) or attention deficit hyperactivity disorder (ADHD).
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Torlinska B, Bath SC, Janjua A, Boelaert K, Chan SY. Iodine Status during Pregnancy in a Region of Mild-to-Moderate Iodine Deficiency is not Associated with Adverse Obstetric Outcomes; Results from the Avon Longitudinal Study of Parents and Children (ALSPAC). Nutrients 2018; 10:nu10030291. [PMID: 29494520 PMCID: PMC5872709 DOI: 10.3390/nu10030291] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/20/2018] [Accepted: 02/22/2018] [Indexed: 12/26/2022] Open
Abstract
Severe iodine deficiency during pregnancy has been associated with pregnancy/neonatal loss, and adverse pregnancy outcomes; however, the impact of mild–to–moderate iodine insufficiency, though prevalent in pregnancy, is not well-documented. We assessed whether mild iodine deficiency during pregnancy was associated with pregnancy/infant loss, or with other adverse pregnancy outcomes. We used samples and data from the Avon Longitudinal Study of Parents and Children (ALSPAC), from 3140 singleton pregnancies and from a further 42 women with pregnancy/infant loss. The group was classified as mildly-to-moderately iodine deficient with a median urinary iodine concentration of 95.3 µg/L (IQR 57.0–153.0; median urinary iodine-to-creatinine ratio (UI/Creat) 124 µg/g, IQR 82–198). The likelihood of pregnancy/infant loss was not different across four UI/Creat groups (<50, 50–149, 150–250, >250 µg/g). The incidence of pre-eclampsia, non-proteinuric gestational hypertension, gestational diabetes, glycosuria, anaemia, post-partum haemorrhage, preterm delivery, mode of delivery, being small for gestational age, and large for gestational age did not differ significantly among UI/Creat groups, nor were there any significant differences in the median UI/Creat. We conclude that maternal iodine status was not associated with adverse pregnancy outcomes in a mildly-to-moderately iodine-deficient pregnant population. However, in view of the low number of women with pregnancy/infant loss in our study, further research is required.
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Affiliation(s)
- Barbara Torlinska
- Institute of Applied Health Research, University of Birmingham, Birmingham B15 2TT, UK.
| | - Sarah C Bath
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
| | - Aisha Janjua
- Birmingham Heartlands Hospital, Birmingham B9 5SS, UK.
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK.
| | - Kristien Boelaert
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK.
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Edgbaston, Birmingham B15 2TH, UK.
| | - Shiao-Yng Chan
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Singapore 119228, Singapore.
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