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Sohn SY, Inoue K, Rhee CM, Leung AM. Risks of Iodine Excess. Endocr Rev 2024:bnae019. [PMID: 38870258 DOI: 10.1210/endrev/bnae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 06/04/2024] [Accepted: 06/12/2024] [Indexed: 06/15/2024]
Abstract
Iodine is a micronutrient that is required for thyroid hormone synthesis. The iodide cycle in thyroid hormone synthesis consists of a series of transport, oxidation, organification, and binding/coupling steps in thyroid follicular cells. Common sources of iodine include the consumption of an iodine-rich diet or iodine fortified foods, the administration of amiodarone, iodine-containing supplements, or iodinated contrast media, and other miscellaneous sources. Methods to assess population iodine status include the measurement of urinary iodine concentrations, blood thyroglobulin levels, prevalence of elevated neonatal TSH levels, and thyroid volume. Although excessive iodine intake or exposure is generally well tolerated, an acute iodine load may result in thyroid dysfunction (hypothyroidism or hyperthyroidism) in certain susceptible individuals due to the failure to escape from the Wolff-Chaikoff effect and to the Jod-Basedow phenomenon, respectively. In this review, we discuss the associations between excessive iodine intake or exposure, with particular focus on iodinated contrast media as a common source of excess iodine in healthcare settings, and risks of incident thyroid dysfunction. We also summarize the risks of iodine excess in vulnerable populations and review current guidelines regarding the screening and monitoring of iodinated contrast-induced thyroid dysfunction. Finally, we discuss the long-term potential nonthyroidal health risks associated with iodine excess and suggest the need for more data to define safe upper limits for iodine intake, particularly in high-risk populations.
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Affiliation(s)
- Seo Young Sohn
- Division of Endocrinology, Department of Internal Medicine, Myongji Hospital, Hanyang University College of Medicine, Goyang, South Korea
| | - Kosuke Inoue
- Department of Social Epidemiology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Hakubi Center, Kyoto University, Kyoto, Japan
| | - Connie M Rhee
- Division of Nephrology, Department of Medicine, Department of Medicine, University of California Los Angeles David Geffen School of Medicine, Los Angeles, California, USA
- Division of Nephrology, Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Angela M Leung
- Division of Endocrinology, Diabetes, and Metabolism; Department of Medicine, University of California Los Angeles David Geffen School of Medicine, Los Angeles, California, USA
- Division of Endocrinology, Diabetes, and Metabolism; Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, USA
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Gunnarsdóttir I, Brantsæter AL. Iodine: a scoping review for Nordic Nutrition Recommendations 2023. Food Nutr Res 2023; 67:10369. [PMID: 38187800 PMCID: PMC10770700 DOI: 10.29219/fnr.v67.10369] [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: 09/13/2021] [Revised: 04/27/2022] [Accepted: 11/10/2023] [Indexed: 01/09/2024] Open
Abstract
Iodine is essential for the synthesis of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). As in many other parts of the world, insufficient iodine intake and consequently insufficient iodine status is a public health challenge in the Nordic and Baltic countries. The main dietary sources of iodine in the Nordic and Baltic countries include cow's milk, saltwater fish, eggs, products containing iodised salt, and iodised table salt. Only Denmark (DK), Finland (FI) and Sweden (SE) have implemented mandatory (DK) or voluntary (SE, FI) salt iodisation. New data, as well as recent studies from the Nordic and Baltic countries, strengthen the evidence that the main health challenges related to insufficient iodine intake remain thyroid function and thyroid disease, mental development, and cognitive function. Excessive intakes can also cause hyperthyroidism, autoimmune thyroid disease, and thyroid cancer.
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Affiliation(s)
- Ingibjörg Gunnarsdóttir
- Faculty of Food Science and Nutrition, University of Iceland, Reykjavik, Iceland
- Unit for Nutrition Research, Landspitali National University Hospital, Reykjavik, Iceland
| | - Anne Lise Brantsæter
- Department of Food Safety, Division of Climate and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
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Ruggeri RM, Barbalace MC, Croce L, Malaguti M, Campennì A, Rotondi M, Cannavò S, Hrelia S. Autoimmune Thyroid Disorders: The Mediterranean Diet as a Protective Choice. Nutrients 2023; 15:3953. [PMID: 37764737 PMCID: PMC10535745 DOI: 10.3390/nu15183953] [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: 08/14/2023] [Revised: 09/06/2023] [Accepted: 09/10/2023] [Indexed: 09/29/2023] Open
Abstract
Autoimmune thyroid diseases are on the rise worldwide, and such a rapid increase is mainly driven by environmental factors related to changed lifestyles in "modern" societies. In this context, diet seems to play a crucial role. An unhealthy high-energy diet, rich in animal fat and proteins, salt and refined sugars (the so-called "Western diet") negatively influences the risk of autoimmunity by altering the immune balance and the gut microbiota composition, enhancing oxidative stress and promoting inflammation. In contrast, the Mediterranean diet represents a unique model of healthy eating, characterized by a high intake of food from vegetable sources, a low consumption of saturated fats in favor of unsaturated fats (mainly, olive oil), a moderate consumption of fish (typically, the small oily fishes) and dairy products, as well as a moderate consumption of wine at meals, and a low intake of meat. Thanks to its nutritional components, the Mediterranean Diet positively influences immune system function, gut microbiota composition, and redox homeostasis, exerting anti-oxidants, anti-inflammatory, and immunomodulatory effects. The present review was aimed at exploring the existing knowledge on the correlations between dietary habits and thyroid autoimmunity, to evaluate the role of the Mediterranean diet as a protective model.
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Affiliation(s)
- Rosaria Maddalena Ruggeri
- Department of Human Pathology of Adulthood and Childhood DETEV “G. Barresi”, Endocrinology Unit, University of Messina, 98125 Messina, Italy;
| | - Maria Cristina Barbalace
- Department for Life Quality Studies, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy; (M.C.B.); (S.H.)
| | - Laura Croce
- Department of Internal Medicine and Therapeutics, Unit of Endocrinology and Metabolism, Laboratory for Endocrine Disruptors, Istituti Clinici Scientifici Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) University of Pavia, 27100 Pavia, Italy; (L.C.); (M.R.)
| | - Marco Malaguti
- Department for Life Quality Studies, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy; (M.C.B.); (S.H.)
| | - Alfredo Campennì
- Department of Biomedical and Dental Sciences and Morpho-Functional Imaging, Unit of Nuclear Medicine, University of Messina, 98125 Messina, Italy;
| | - Mario Rotondi
- Department of Internal Medicine and Therapeutics, Unit of Endocrinology and Metabolism, Laboratory for Endocrine Disruptors, Istituti Clinici Scientifici Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) University of Pavia, 27100 Pavia, Italy; (L.C.); (M.R.)
| | - Salvatore Cannavò
- Department of Human Pathology of Adulthood and Childhood DETEV “G. Barresi”, Endocrinology Unit, University of Messina, 98125 Messina, Italy;
| | - Silvana Hrelia
- Department for Life Quality Studies, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy; (M.C.B.); (S.H.)
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Chen W, Wang W, Gao M, Chen Y, Guo W, Dong S, Sun H, Pan Z, Pearce EN, Tan L, Shen J, Zhang W. Iodine Intakes of <150 μg/day or >550 μg/day are Not Recommended during Pregnancy: A Balance Study. J Nutr 2023; 153:2041-2050. [PMID: 37100687 DOI: 10.1016/j.tjnut.2022.10.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/25/2022] [Accepted: 10/28/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Adequate iodine intake during pregnancy is critical for maintaining maternal and fetal thyroid function and development. There are only limited data from iodine-balance studies to inform iodine requirements during pregnancy. OBJECTIVES This is an iodine-balance study conducted to explore the associations among iodine intake, excretion, and retention to provide information regarding iodine requirements during pregnancy. METHODS A 7-d iodine-balance experiment enrolled 93 healthy pregnant Chinese women from Hebei, Tanjin, and Shandong. Duplicates of all foods and beverages consumed were systematically collected and measured for iodine content. Iodine excretion was measured by collecting 24-h urine and feces samples. Simple linear regression models were used to assess relationships between total iodine intake and iodine retention, whereas mixed effect models were used to assess the relationship between daily iodine intake and iodine retention. RESULTS The mean ± SD age of participating pregnant women was 29 ± 2 y at a median 22 (IQR: 13-30) wk of gestation. The mean 7-d iodine retention was 43.0 ± 1060 μg/7 d. A negative iodine balance was present in 56% of women whereas 44% had a positive balance. Pregnant women with iodine intakes <150 μg/d were in negative balance whereas those with intakes >550 μg/d were in positive balance. The daily iodine intake at zero balance was 343 μg/d, which was higher in women from Shandong (492 μg/d) than in those from Hebei and Tianjin (202 μg/d). CONCLUSIONS Iodine intake at zero balance determined in pregnant women with adequate iodine nutrition is 202 μg/d, and the calculated recommended nutrient intake (RNI) is 280 μg/d. Iodine intakes of <150 μg/d and >550 μg/d are not recommended during pregnancy. This trial was registered at clinicaltrials.gov as NCT03710148.
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Affiliation(s)
- Wen Chen
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China; Department of Endocrinology and Metabolism, Health care and Prevention, Tianjin Medical University General Hospital, Tianjin, China
| | - Wei Wang
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China; The Department of Health Services and Management, School of Management, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Min Gao
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Yanting Chen
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Wenxing Guo
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Shuyao Dong
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Hao Sun
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Ziyun Pan
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA, USA
| | - Long Tan
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Jun Shen
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Wanqi Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China; Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on Environment, Nutrition and Public Health, Tianjin, China; Department of Endocrinology and Metabolism, Health care and Prevention, Tianjin Medical University General Hospital, Tianjin, China.
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Wan S, Jin B, Ren B, Boah M, Shen H. Relationship between mild iodine deficiency in pregnant women and thyroid function: A meta-analysis. J Trace Elem Med Biol 2023; 78:127197. [PMID: 37209527 DOI: 10.1016/j.jtemb.2023.127197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/27/2023] [Accepted: 05/05/2023] [Indexed: 05/22/2023]
Abstract
BACKGROUND Pregnant women are among the key groups in iodine nutrition evaluation. The purpose of the present study was to summarize the evidence supporting the relationship between mild iodine deficiency (UIC: 100-150 μg/L) in pregnant women and levels of thyroid function tests. METHODS This review follows the guidelines for systematic reviews (PRISMA 2020). Three electronic databases (PubMed, Medline, and Embase) were searched for relevant publications in English on the association between mild iodine deficiency in pregnant women and thyroid function. Articles published in Chinese were searched in China's electronic databases (CNKI, WanFang, CBM, and WeiPu). Pooled effects were presented as standardized mean differences (SMDs) and odds ratios (ORs) with 95% confidence intervals (CIs) using fixed or random effect models, respectively. This meta-analysis was registered at www.crd.york.ac.uk/prospero as CRD42019128120. RESULTS We summarized the results from 7 articles with 8261 participants. The overall pooled results showed that the levels of FT3, FT4, and abnormal TgAb (the antibody levels exceeded the upper limit of the reference range) were significantly increased in pregnant women with mild iodine deficiency compared to pregnant women with adequate iodine status (FT3: SMD=0.854, 95% CI: 0.188, 1.520; FT4: SMD=0.550, 95% CI: 0.050, 1.051; TgAb: OR=1.292, 95% CI: 1.095; 1.524). Subgroup analysis was carried out on the sample size, ethnicity, country, and gestation of FT3, FT4, and TSH, but no plausible factor was found. Egger's tests indicated no publication bias.The increase in FT3 and FT4, as well as TgAb levels, in pregnant women is associated with mild iodine deficiency. CONCLUSION Mild iodine deficiency is associated with an increase in FT3,FT4 and TgAb levels in pregnant women. Mild iodine deficiency may increase the risk of thyroid dysfunction in pregnant women.
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Affiliation(s)
- Siyuan Wan
- Department of Preventive Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang, China.
| | - Baiming Jin
- Department of Preventive Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang, China
| | - Bingxuan Ren
- Centre for Endemic Disease Control, Chinese Centre for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang, China
| | - Michael Boah
- Department of Epidemiology, Biostatistics and Disease Control, School of Public Health, University for Development Studies, Tamale, Ghana
| | - Hongmei Shen
- Centre for Endemic Disease Control, Chinese Centre for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang, China.
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Croce L, Chiovato L, Tonacchera M, Petrosino E, Tanda ML, Moleti M, Magri F, Olivieri A, Pearce EN, Rotondi M. Iodine status and supplementation in pregnancy: an overview of the evidence provided by meta-analyses. Rev Endocr Metab Disord 2023; 24:241-250. [PMID: 36227457 PMCID: PMC10023614 DOI: 10.1007/s11154-022-09760-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/29/2022] [Indexed: 10/17/2022]
Abstract
Iodine supplementation during pregnancy in areas with mild-moderate deficiency is still a matter of debate. The present study aimed at systematically reviewing currently available evidences provided by meta-analyses with the aim to further clarify controversial aspects regarding the need of iodine supplementation in pregnancy as well as to provide guidance on clinical decision-making, even in areas with mild-moderate deficiency. Medline, Embase and Cochrane search from 1969 to 2022 were performed. For the purpose of this review, only studies containing meta-analytic data were selected. A total of 7 meta-analyses were retrieved. Four meta-analyses evaluated the relationship between iodine status during pregnancy and neonatal and maternal outcomes suggesting the existence of a U-shaped correlation between iodine status and several maternal and neonatal consequences, especially if iodine status is evaluated at the beginning of pregnancy. Three meta-analyses evaluating the results of intervention trials failed to provide straightforward conclusions on the benefits of iodine supplementation in pregnant women in areas with mild-moderate iodine deficiency. Although evidence coming from meta-analyses suggests a role of iodine status during pregnancy in determining maternal and child outcomes, results of meta-analyses of intervention trials are still controversial. Several factors including, degree of iodine deficiency, and pooling studies conducted in areas with different iodine intake, may account for the lack of benefits reported by meta-analyses of intervention trials. More high-quality, randomized, controlled trials including information on timing, dose and regimen of iodine supplementation are needed to further elucidate this issue.
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Affiliation(s)
- Laura Croce
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia (PV), 27100, Pavia, Italy
- Istituti Clinici Scientifici Maugeri IRCCS, Unit of Internal Medicine and Endocrinology, Laboratory for Endocrine Disruptors, 27100, Pavia, PV, Italy
| | - Luca Chiovato
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia (PV), 27100, Pavia, Italy
- Istituti Clinici Scientifici Maugeri IRCCS, Unit of Internal Medicine and Endocrinology, Laboratory for Endocrine Disruptors, 27100, Pavia, PV, Italy
| | - Massimo Tonacchera
- Endocrinology Section, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Elena Petrosino
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia (PV), 27100, Pavia, Italy
- Istituti Clinici Scientifici Maugeri IRCCS, Unit of Internal Medicine and Endocrinology, Laboratory for Endocrine Disruptors, 27100, Pavia, PV, Italy
| | - Maria Laura Tanda
- Department of Medicine and Surgery, University of Insubria, Varese, Italy
| | - Mariacarla Moleti
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Flavia Magri
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia (PV), 27100, Pavia, Italy
- Istituti Clinici Scientifici Maugeri IRCCS, Unit of Internal Medicine and Endocrinology, Laboratory for Endocrine Disruptors, 27100, Pavia, PV, Italy
| | - Antonella Olivieri
- Department of Cardiovascular and Endocrine-Metabolic Diseases and Aging, Italian National Institute of Health, Rome, Italy
| | - Elizabeth N Pearce
- Section of Endocrinology Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA, USA
| | - Mario Rotondi
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia (PV), 27100, Pavia, Italy.
- Istituti Clinici Scientifici Maugeri IRCCS, Unit of Internal Medicine and Endocrinology, Laboratory for Endocrine Disruptors, 27100, Pavia, PV, Italy.
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Tadesse S, Hymete A, Lieberman M, Gebreyesus SH, Ashenef A. Iodine status, household salt iodine content, knowledge and practice assessment among pregnant women in Butajira, South Central Ethiopia. PLoS One 2022; 17:e0277208. [PMID: 36441747 PMCID: PMC9704620 DOI: 10.1371/journal.pone.0277208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 10/22/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Iodine is one of the crucial micronutrients needed by the human body, and is vitally important during pregnancy. This study aimed to determine the relationship between the iodine status of pregnant women and their knowledge, and practices regarding iodized salt. All participants were enrolled in the Butajira nutrition, mental health and pregnancy (BUNMAP) cohort, Butajira, Ethiopia in February-May, 2019. METHODS In this cross-sectional study, 152 pregnant women without hypertension or known thyroid disease before or during pregnancy were randomly selected from the BUNMAP mother to child cohort (n = 832). Spot urine samples were collected to estimate the level of urinary iodine concentration (UIC). Salt samples were also collected from their homes. The Sandall-Kolthoff (S-K) method was used to measure the level of iodine in the urine samples, and iodometric titration was used to measure the level of iodine in the salt. Data was entered and cleaned using Epi-info version 3.5.3 and then exported to SPSS version 20 for further analysis. Multivariate logistic regression analysis was performed to identify associations in the collected data. RESULTS The WHO recommended level of iodine for populations of pregnant women is 150-249 F06Dg/L. The median UIC among pregnant women in this study was 151.2 μg/L [interquartile range (IQR) = 85.5-236.2 F06Dg/L], at the low end of this range. About half (49.65%) of the participants were likely to be iodine deficient. There was a significant association between having a formal job (AOR = 2.56; CI = 1.11-5.96) and iodine sufficiency. Based on a cutoff of >15 ppm (mg/kg), 91.7% (95% CI: 87.2-96.2) of the salts collected from the household had adequate iodine content. The median iodine level of the collected salt samples was 34.9 mg/kg (ppm) (IQR = 24.2-44.6 mg/kg). CONCLUSIONS The UNICEF 2018 guidelines for adequate iodine nutrition in pregnant women include both a recommended median range of 150-249 μg/L, and an upper limit of 20% on the fraction of the population with UIC below 50 μg/L. Because our study population's median level is 151.2 μg/L and the percentage of pregnant women with urinary iodine concentration of less than 50 μg/L is 9.7% (14/145), the women received adequate iodine nutrition. The availability of adequately iodized salt in households is more than 90%, as recommended by WHO. In light of previous iodine deficiency in this region of Ethiopia, the salt iodization program promotes the health of babies and mothers.
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Affiliation(s)
- Senait Tadesse
- Department of Pharmaceutical Chemistry and Pharmacognosy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ariaya Hymete
- Department of Pharmaceutical Chemistry and Pharmacognosy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Marya Lieberman
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN, United States of America
| | - Seifu Hagos Gebreyesus
- Department of Nutrition and Dietetics, School of Public Health, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ayenew Ashenef
- Department of Pharmaceutical Chemistry and Pharmacognosy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
- * E-mail:
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Evaluation of Iodine Supplementation in Pregnant Women with Gestational Diabetes: IODIAB Study. Healthcare (Basel) 2022; 10:healthcare10122388. [PMID: 36553911 PMCID: PMC9778216 DOI: 10.3390/healthcare10122388] [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: 09/26/2022] [Revised: 11/06/2022] [Accepted: 11/11/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Iodine supplementation is indicated by the French National Authority for Health (HAS) and the World Health Organization (WHO) during pregnancy. This study investigates whether this supplementation is consistently prescribed in line with WHO recommendations in pregnant women diagnosed with gestational diabetes mellitus. METHOD A total of 99 women with a diagnosis of gestational diabetes were included in the study and were all closely monitored. RESULTS Only 17 (17.2%) patients received the recommended iodine supplementation. The follow-up, whether conducted by a gynecologist or midwife, did not influence the prescription of iodine supplements. By contrast, 72 (72.7%) of patients received folic acid supplementation. CONCLUSIONS The prescription of iodine supplementation for the pregnant women included in our study is insufficient. Few practitioners seem aware of the recommendations, even when the pregnancy is complicated by gestational diabetes.
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Abstract
BACKGROUND Increasingly, patients are asking their physicians about the benefits of dietary and alternative approaches to manage their diseases, including thyroid disease. We seek to review the evidence behind several of the vitamins, minerals, complementary medicines, and elimination diets that patients are most commonly using for the treatment of thyroid disorders. SUMMARY Several trace elements are essential to normal thyroid function, and their supplementation has been studied in various capacities. Iodine supplementation has been implemented on national scales through universal salt iodization with great success in preventing severe thyroid disease, but can conversely cause thyroid disorders when given in excess. Selenium and zinc supplementation has been found to be beneficial in specific populations with otherwise limited generalizability. Other minerals, such as vitamin B12, low-dose naltrexone, and ashwagandha root extract, have little to no evidence of any impact on thyroid disorders. Avoidance of gluten and dairy has positive impacts only in patients with concomitant sensitivities to those substances, likely by improving absorption of levothyroxine. Avoidance of cruciferous vegetables and soy has little proven benefit in patients with thyroid disorders. CONCLUSION While many patients are seeking to avoid conventional therapy and instead turn to alternative and dietary approaches to thyroid disease management, many of the most popular approaches have no proven benefit or have not been well studied. It is our responsibility to educate our patients about the evidence for or against benefit, potential harms, or dearth of knowledge behind these strategies.
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Affiliation(s)
- Dana Larsen
- Division of Endocrinology, Diabetes and Bone Disease, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Sargun Singh
- Government Medical College Amritsar, Amritsar, Punjab, India
| | - Maria Brito
- Division of Endocrinology, Diabetes and Bone Disease, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA
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Businge CB, Musarurwa HT, Longo-Mbenza B, Kengne AP. The prevalence of insufficient iodine intake in pregnancy in Africa: a systematic review and meta-analysis. Syst Rev 2022; 11:231. [PMID: 36303220 PMCID: PMC9615360 DOI: 10.1186/s13643-022-02072-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 09/12/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Fortification of foodstuffs with iodine, mainly through iodization of salt, which commenced in several African countries after 1995 is the main method for mitigating iodine deficiency in Africa. We assessed the degree of iodine nutrition in pregnancy across Africa before and after the implementation of national iodine fortification programs (CRD42018099434). METHODS Electronic databases and gray literature were searched for baseline data before implementation of population-based iodine supplementation and for follow-up data up to September 2020. R-metamedian and metamean packages were used to pool country-specific median urinary iodine concentration (UIC) estimates and derived mean UIC from studies with similar features. RESULTS Of 54 African countries, 23 had data on iodine nutrition in pregnancy mostly from subnational samples. Data before 1995 showed that severe iodine deficiency was prevalent in pregnancy with a pooled pregnancy median UIC of 28.6 μg/L (95% CI 7.6-49.5). By 2005, five studies revealed a trend towards improvement in iodine nutrition state in pregnancy with a pooled pregnancy median UIC of 174.1 μg/L (95% CI 90.4-257.7). Between 2005 and 2020 increased numbers of national and subnational studies revealed that few African countries had sufficient, while most had mildly inadequate, and some severely inadequate iodine nutrition in pregnancy. The pooled pregnancy median UIC was 145 μg/L (95% CI 126-172). CONCLUSION Improvement in iodine nutrition status in pregnancy following the introduction of fortification of foodstuffs with iodine in Africa is sub-optimal, exposing a large proportion of pregnant women to the risk of iodine deficiency and associated disorders. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42018099434.
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Affiliation(s)
- Charles Bitamazire Businge
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa. .,Department of Obstetrics and Gynaecology, Faculty of Health Sciences, Walter Sisulu University, Private Bag x1 WSU, Mthatha, 5117, South Africa.
| | - Hannibal Tafadzwa Musarurwa
- Department of Biological Sciences, Faculty of Health Sciences, Walter Sisulu University, Private Bag x1 WSU, Mthatha, 5117, South Africa
| | | | - Andre Pascal Kengne
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo.,Non-Communicable Disease Research Unit, South African Medical Research Council, Cape Town, South Africa
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Kermoison G, Draganescu C. Role of Dietary and Environmental Factors on Thyroid Cancer in Romania: A Brief Review. Diagnostics (Basel) 2022; 12:diagnostics12081959. [PMID: 36010309 PMCID: PMC9406885 DOI: 10.3390/diagnostics12081959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/26/2022] [Accepted: 08/05/2022] [Indexed: 11/25/2022] Open
Abstract
Thyroid cancer is the most common endocrine tumor, accounting for about 1% of all human malignancies. There are environmental factors that can potentiate the onset of thyroid cancer, in particular pollutants, lifestyle or radiation exposure. Another major cause responsible for the appearance of thyroid cancer is the habitat in endemic areas where there is a deficit of iodine in the soil, drinking water and food. We operated using the PubMed database in order to find the articles of interest. After a wary review of the literature, we designated the relevant articles necessary for our study including various factors such as alimentation, effects of the Chernobyl fallout radiation and the iodine and vitamin D deficiency in Romania. The aim of this article is to make a correlation between the different environmental and dietary factors in Romania, and the increased incidence of thyroid cancer.
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Affiliation(s)
- Gilles Kermoison
- Doctoral School of Iuliu Hațieganu, University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Nuclear Medicine Department, “Prof. Dr. Ion Chiricuta” Institute of Oncology, 400015 Cluj-Napoca, Romania
- Nuclear Medicine Department, University Institut of Martinique, 97200 Fort-de-France, France
- Correspondence: ; Tel.: +40-756-328-839
| | - Ciprian Draganescu
- Nuclear Medicine Department, University Institut of Martinique, 97200 Fort-de-France, France
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12
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Ilias I, Milionis C, Koukkou E. Further understanding of thyroid function in pregnant women. Expert Rev Endocrinol Metab 2022; 17:365-374. [PMID: 35831988 DOI: 10.1080/17446651.2022.2099372] [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: 01/10/2022] [Accepted: 07/05/2022] [Indexed: 10/17/2022]
Abstract
INTRODUCTION Normal thyroid status throughout pregnancy is important for both maternal and fetal health. Despite the bulk of contemporary research honing on thyroid function in gestation and the relevant disorders, there are still gaps in our current knowledge about the etiology and treatment of thyroid diseases in pregnant women. AREAS COVERED This article analyzes the adaptation of the thyroid gland to gestational physiological changes and attempts to explain the effect of several factors on thyroid function in pregnancy. It also stresses proper utilization and interpretation of thyroid tests during pregnancy and underlines the significance of proper screening and treatment of pregnant women aiming at favorable health outcomes. EXPERT OPINION Appropriate strategies for diagnosing and treating thyroid disease in pregnancy are important. Laboratory thyroid testing plays a leading role, but test results should be interpreted with caution. Given the possible serious maternal and fetal/neonatal complications of thyroid disease in pregnancy, we recommend universal screening with TSH measurements of all pregnant women. Additional assessment with determination of the levels of free thyroid hormones and thyroid antibodies may be necessary under certain conditions. The economic burden of such interventions should be considered.
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Affiliation(s)
- Ioannis Ilias
- Department of Endocrinology, Diabetes and Metabolism, Elena Venizelou Hospital, Athens, Greece
| | - Charalampos Milionis
- Department of Endocrinology, Diabetes and Metabolism, Elena Venizelou Hospital, Athens, Greece
| | - Eftychia Koukkou
- Department of Endocrinology, Diabetes and Metabolism, Elena Venizelou Hospital, Athens, Greece
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13
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Breast Milk Iodine Concentration (BMIC) as a Biomarker of Iodine Status in Lactating Women and Children <2 Years of Age: A Systematic Review. Nutrients 2022; 14:nu14091691. [PMID: 35565659 PMCID: PMC9104537 DOI: 10.3390/nu14091691] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/28/2022] [Accepted: 04/01/2022] [Indexed: 01/01/2023] Open
Abstract
Background: Iodine is needed for the production of thyroid hormones, which are essential for infant growth and development. Given that there are wide variations in breast milk iodine concentration (BMIC) and urinary iodine concentration (UIC), it is unclear if BMIC is associated with UIC in populations residing in iodine sufficient or deficient areas. Aim: To investigate if BMIC can be used as a biomarker for iodine status in lactating women and children <2 years of age. Methods: Electronic databases; PubMed, Web of Science and Scopus were searched until year 2021, for studies investigating the relationship between BMIC and UIC. Studies were reviewed for eligibility, according to inclusion and exclusion criteria, followed by data extraction, according to the PRISMA guidelines. Results: Overall, 51 studies met the criteria for inclusion in the systematic review. BMIC ranged from 18 to 1153 µg/L. In iodine-deficient and iodine-sufficient lactating women, BMIC ranged from 26 to 185 µg/L and 15 to 1006 µg/L, respectively. In most studies, the categorisation of iodine status assessed by median UIC was consistent with the categorisation of iodine status assessed by median BMIC cut off of ≥100 µg/L, to determine iodine sufficiency in lactating women and children <2 years of age. Conclusions: The systematic review indicated that BMIC is a promising biomarker of iodine status in lactating women and children <2 years of age. However, these data need to be interpreted cautiously, given the study limitations in the included studies. Future studies should consider investigating the optimal median BMIC, as there is a lack of high-quality observational and intervention studies in lactating women and infants.
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14
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Lee SY, Pearce EN. Assessment and treatment of thyroid disorders in pregnancy and the postpartum period. Nat Rev Endocrinol 2022; 18:158-171. [PMID: 34983968 PMCID: PMC9020832 DOI: 10.1038/s41574-021-00604-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/19/2021] [Indexed: 12/13/2022]
Abstract
Thyroid disorders are prevalent in pregnant women. Furthermore, thyroid hormone has a critical role in fetal development and thyroid dysfunction can adversely affect obstetric outcomes. Thus, the appropriate management of hyperthyroidism, most commonly caused by Graves disease, and hypothyroidism, which in iodine sufficient regions is most commonly caused by Hashimoto thyroiditis, in pregnancy is important for the health of both pregnant women and their offspring. Gestational transient thyrotoxicosis can also occur during pregnancy and should be differentiated from Graves disease. Effects of thyroid autoimmunity and subclinical hypothyroidism in pregnancy remain controversial. Iodine deficiency is the leading cause of hypothyroidism worldwide. Despite global efforts to eradicate iodine deficiency disorders, pregnant women remain at risk of iodine deficiency due to increased iodine requirements during gestation. The incidence of thyroid cancer is increasing worldwide, including in young adults. As such, the diagnosis of thyroid nodules or thyroid cancer during pregnancy is becoming more frequent. The evaluation and management of thyroid nodules and thyroid cancer in pregnancy pose a particular challenge. Postpartum thyroiditis can occur up to 1 year after delivery and must be differentiated from other forms of thyroid dysfunction, as treatment differs. This Review provides current evidence and recommendations for the evaluation and management of thyroid disorders in pregnancy and in the postpartum period.
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Affiliation(s)
- Sun Y Lee
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA, USA
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA, USA.
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15
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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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16
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Nationwide Representative Survey of Dietary Iodine Intake and Urinary Excretion in Postpartum Korean Women. Nutrients 2021; 13:nu13113955. [PMID: 34836212 PMCID: PMC8623058 DOI: 10.3390/nu13113955] [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: 09/28/2021] [Revised: 10/31/2021] [Accepted: 11/03/2021] [Indexed: 11/17/2022] Open
Abstract
Iodine is an essential component of thyroid hormones, but excessive iodine intake can lead to thyroid dysfunction. Traditionally, Korean mothers consume brown seaweed soup (miyeokguk), a high source of iodine, after childbirth. There is controversy regarding the effects of excessive postpartum iodine intake on the health of mothers and infants. Thus far, there have been no nationwide large-scale surveys regarding the status of iodine intake among postpartum women in Korea. Therefore, we conducted a nationwide survey of postpartum dietary iodine intake among Korean women. In total, 1054 Korean women aged ≥19 years, at less than 8 weeks postpartum, participated in this survey. Dietary data were collected using self-reported 2-day dietary records, along with before-and-after meal photos. To evaluate the correlation between dietary iodine and urinary iodine excretion (UIE), spot urine, and 24 h urine samples were collected from 98 and 29 participants, respectively. The mean daily iodine intake among all participants was 2945.6 μg, and it gradually decreased over time after childbirth. Dietary iodine intake was significantly correlated with 24 h UIE (r = 0.396, p < 0.05) and spot urine UIE (r = 0.312, p < 0.05). Follow-up studies are required to examine the influence of excessive postpartum iodine intake on thyroid health in mothers and their infants.
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17
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Opazo MC, Rivera JC, Gonzalez PA, Bueno SM, Kalergis AM, Riedel CA. Thyroid Gene Mutations in Pregnant and Breastfeeding Women Diagnosed With Transient Congenital Hypothyroidism: Implications for the Offspring's Health. Front Endocrinol (Lausanne) 2021; 12:679002. [PMID: 34721286 PMCID: PMC8551387 DOI: 10.3389/fendo.2021.679002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 09/13/2021] [Indexed: 12/21/2022] Open
Abstract
Fetus and infants require appropriate thyroid hormone levels and iodine during pregnancy and lactation. Nature endorses the mother to supply thyroid hormones to the fetus and iodine to the lactating infant. Genetic variations on thyroid proteins that cause dyshormonogenic congenital hypothyroidism could in pregnant and breastfeeding women impair the delivery of thyroid hormones and iodine to the offspring. The review discusses maternal genetic variations in thyroid proteins that, in the context of pregnancy and/or breastfeeding, could trigger thyroid hormone deficiency or iodide transport defect that will affect the proper development of the offspring.
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Affiliation(s)
- Maria C. Opazo
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias de la Vida, Departamento de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile
- Instituto de Ciencias Naturales, Facultad de Medicina Veterinaria y Agronomía, Universidad de las Américas, Santiago, Chile
| | - Juan Carlos Rivera
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias de la Vida, Departamento de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile
| | - Pablo A. Gonzalez
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susan M. Bueno
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis M. Kalergis
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Endocrinología, Facultad de Medicina, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia A. Riedel
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias de la Vida, Departamento de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile
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18
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Delshad H, Raeisi A, Abdollahi Z, Tohidi M, Hedayati M, Mirmiran P, Nobakht F, Azizi F. Iodine supplementation for pregnant women: a cross-sectional national interventional study. J Endocrinol Invest 2021; 44:2307-2314. [PMID: 33704696 DOI: 10.1007/s40618-021-01538-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/16/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Although Iran has been considered iodine replete since 2000, the first national survey of iodine intake among Iranian pregnant women in 2014 indicated that despite the adequate intake of iodine by the general population, this vulnerable group has moderate iodine deficiency. Therefore, in this national cross-sectional interventional study, we aimed to assess the iodine intake and thyroid function of Iranian pregnant women 2 years after implementing national iodine supplementation for this vulnerable group. MATERIALS AND METHODS In this cross-sectional study, we conducted a national interventional survey of pregnant women. A total of 1200 pregnant women (400 women from each trimester) from 12 provinces of Iran were recruited from the antenatal care clinics from October 2018 to March 2019. The median urinary iodine concentration (MUIC), as an indicator of iodine status in three spot urine samples, was measured, along with the serum total T4 (TT4), thyrotropin (TSH), thyroglobulin (Tg), thyroid peroxidase antibody (TPO-Ab), and iodine content of household salt. RESULTS The mean age of the cohort was 28 ± 6.2 years, with the mean gestational age of 22.7 ± 13.0 weeks. The overall MUIC (IQR) of pregnant women was 188 µg/L (124.2-263 µg/L). Also, the MUICs in the three trimesters of pregnancy were 174 µg/L (110-254), 175 µg/L (116-251), and 165 µg/L (114-235), respectively. The MUICs ≥ 150, 100-149, and < 100 µg/L were found in 63, 19.8, and 16.2% of the subjects, respectively. The mean TT4 level was 12 ± 4.5 µg/dL, and the median (IQR) level of TSH was 2.37 mIU/L (1.66-3.18 mIU/L). According to our local reference range, 118 (10.5%) pregnant women had subclinical hypothyroidism, 6 (0.53%) women had isolated hypothyroxinemia, and 65 (5.7%) women were TPO-Ab positive. Also, the median (IQR) level of Tg was 10.08 µg/dL (5.7-20.4 µg/dL), and the median iodine content of household salt was 29.6 µg/g; the iodine content was ≥ 30 µg/g in 85% of household salt. The results showed that more than 95% of households were under iodized salt coverage. CONCLUSION The results of this study indicated that iodine supplementation with at least 150 µg of iodine per day improved the iodine intake of pregnant women. Except for subclinical hypothyroidism, the prevalence of clinical hypothyroidism, clinical/subclinical thyrotoxicosis, TPO-Ab positivity, and isolated hypothyroxinemia decreased significantly, which emphasizes the importance of iodine supplementation during pregnancy.
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Affiliation(s)
- H Delshad
- Micronutrient Research Office, Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - A Raeisi
- Iran's Ministry of Health and Medical Education, Tehran, Iran
| | - Z Abdollahi
- General of Nutrition Department, Iran's Ministry of Health and Medical Education, Tehran, Iran
| | - M Tohidi
- Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - M Hedayati
- Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - P Mirmiran
- Nutrition Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - F Nobakht
- National IDD Program, Iran's Ministry of Health and Medical Education, Tehran, Iran
| | - F Azizi
- Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P. O. Box 19395-4763, Tehran, Iran.
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Ahmed I, Ma V, Liu Y, Khan MS, Liu Z, Zhang C, Paidi SK, Manno FAM, Amjad N, Manno SHC, Ahmed R, Law AWL, Ali A, Raza F, Zhang Y, Cho WCS, Barman I, Alda M, Bergink V, Lau C. Lithium from breast-milk inhibits thyroid iodine uptake and hormone production, which are remedied by maternal iodine supplementation. Bipolar Disord 2021; 23:615-625. [PMID: 33507599 DOI: 10.1111/bdi.13047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 01/05/2021] [Accepted: 01/21/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Lithium is especially taken as a maintenance medication for Bipolar Disorder. In women with bipolar disorder, lithium is often effective during postpartum period, but breast-feeding for medicated mothers is controversial because of harmful effects for her child. At present, the biological mechanisms of lithium are not well-understood, affecting its usage and overall health implications. PROCEDURE We developed a rat lithium and breast-feeding model at human therapeutic levels to study the effects of lithium exposure through breast-milk on pups' thyroid function. Novel laser analytical spectroscopy, along with traditional blood and immunohistochemical tests, were applied to further investigate the mechanisms behind the thyroid dysfunction. Maternal iodine supplementation was evaluated as a therapeutic method to address the pups' thyroid dysfunction. RESULTS Pups exposed to lithium via breastmilk, even with the dam on a sub-therapeutic level, experienced weight gain, reduced blood thyroxine (T4 ), and elevated blood urea nitrogen, indicating effects on thyroid and kidney function. We show that lithium inhibited iodine uptake by thyroid follicles, initiating a mechanism that reduced iodination of tyrosine, thyroglobulin cleavage, and thyroid hormone production. Importantly, infant thyroid function can be significantly improved by administering supplementary iodine to the medicated dam's diet during breast-feeding. CONCLUSION These results elucidate the mechanisms of lithium in thyroid function, provide valuable information on use postpartum, and suggest a clinically applicable remedy to side-effects. The results are particularly important for patients (and their infants) who respond well to lithium and need, or choose, to breast-feed.
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Affiliation(s)
- Irfan Ahmed
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China.,Department of Electrical Engineering, Sukkur IBA University, Sukkur, Pakistan
| | - Victor Ma
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China
| | - Yuanchao Liu
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | | | - Zhenhui Liu
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Chi Zhang
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Santosh Kumar Paidi
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Francis A M Manno
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | - Noreen Amjad
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | - Sinai H C Manno
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China.,Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Rafay Ahmed
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | - Alan W L Law
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | - Ahmed Ali
- Department of Electrical Engineering, Sukkur IBA University, Sukkur, Pakistan
| | - Faizan Raza
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi'an Jiaotong University, Xi'an, China
| | - Yanpeng Zhang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi'an Jiaotong University, Xi'an, China
| | - William C S Cho
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong SAR, China
| | - Ishan Barman
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin Alda
- Department of Psychiatry, Dalhousie University, Halifax, Canada
| | - Veerle Bergink
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Obstetrics, Gynecology and Reproductive Science, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Condon Lau
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
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20
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Monaghan AM, Mulhern MS, Mc Sorley EM, Strain J, Winter T, van Wijngaarden E, Myers GJ, Davidson PW, Shamlaye C, Gedeon J, Yeates AJ. Associations between maternal thyroid function in pregnancy and child neurodevelopmental outcomes at 20 months in the Seychelles Child Development Study, Nutrition Cohort 2 (SCDS NC2). J Nutr Sci 2021; 10:e71. [PMID: 34527229 PMCID: PMC8411260 DOI: 10.1017/jns.2021.66] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/06/2021] [Indexed: 12/24/2022] Open
Abstract
Maternal thyroid hormones facilitate optimal foetal neurodevelopment; however, the exact role of the thyroid hormones on specific cognitive outcomes is unknown. The present study aimed to investigate associations between maternal thyroid function and neurodevelopmental outcomes in the Seychelles Child Development Study (SCDS) Nutrition 2 cohort (n 1328). Maternal free thyroid hormones (fT3, fT4 and fTSH) were assessed at 28 weeks' gestation with a range of child cognitive outcomes analysed at 20 months. Dietary iodine intake was analysed for a subset of women through a Food Frequency Questionnaire. Linear regression analysis was used to test associations between serum concentrations of maternal thyroid hormones and child neurodevelopment outcomes. Thyroid hormones were analysed as continuous data and categorised as quintiles. 95% of mothers had optimal thyroid function based on fTSH concentrations. Overall, the present study shows that maternal thyroid function is not associated with neurodevelopmental outcomes in this high fish-eating population. However, a positive association, using quintiles for fT3, was reported for the Mental Developmental Index, between Q3 v. Q4 (β 0⋅073; P 0⋅043) and for Q3 v. Q5 (β value 0⋅086; P 0⋅018). To conclude, mothers in our cohort, who largely have optimal thyroid function and iodine intakes, appear able to regulate thyroid function throughout pregnancy to meet neurodevelopmental needs. However, it is possible that minor imbalances of fT3, as indicated from our secondary analysis, may impact offspring neurodevelopment. Further investigation of the relationship between maternal thyroid function and infant neurodevelopment is warranted, particularly in populations with different dietary patterns and thereby iodine intakes.
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Affiliation(s)
- Anna M. Monaghan
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, UK
| | - Maria S. Mulhern
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, UK
| | - Emeir M. Mc Sorley
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, UK
| | - J.J. Strain
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, UK
| | - Theresa Winter
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Germany
| | - Edwin van Wijngaarden
- Department of Community and Preventive Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Gary J. Myers
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Philip W. Davidson
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | | | - Jude Gedeon
- Child Development Centre, Ministry of Health, Mahe, Republic of Seychelles
| | - Alison J. Yeates
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, UK
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21
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Purdue-Smithe AC, Männistö T, Reische E, Kannan K, Kim UJ, Suvanto E, Surcel HM, Gissler M, Mills JL. Iodine and thyroid status during pregnancy and risk of stillbirth: A population-based nested case-control study. MATERNAL AND CHILD NUTRITION 2021; 18:e13252. [PMID: 34350728 PMCID: PMC8710109 DOI: 10.1111/mcn.13252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/21/2021] [Accepted: 07/13/2021] [Indexed: 11/26/2022]
Abstract
Prior research suggests that severe iodine deficiency in pregnancy may be associated with stillbirth. However, the relationship between mild to moderate iodine insufficiency, which is prevalent even in developed countries, and risk of stillbirth is unclear. We thus examined associations of iodine status and risk of stillbirth in a prospective population‐based nested case–control study in Finland, a mild to moderately iodine insufficient population. Stillbirth cases (n = 199) and unaffected controls (n = 249) were randomly selected from among all singleton births in Finland from 2012 to 2013. Serum samples were collected between 10 and 14 weeks gestation and analysed for iodide, thyroglobulin (Tg) and thyroid‐stimulating hormone (TSH). Odds ratios (ORs) and 95% confidence intervals (CIs) for stillbirth were estimated using logistic regression. After adjusting for maternal age, prepregnancy body mass index, socio‐economic status and other factors, neither high nor low serum iodide was associated with risk of stillbirth (Q1 vs. Q2–Q3 OR = 0.92, 95% CI = 0.78–1.09; Q4 vs. Q2–Q3 OR = 0.78; 95% CI = 0.45–1.33). Tg and TSH were also not associated with risk of stillbirth in adjusted models. Maternal iodine status was not associated with stillbirth risk in this mildly to moderately iodine‐deficient population. Tg and TSH, which reflect functional iodine status, were also not associated with stillbirth risk. The lack of associations observed between serum iodide, TSH and Tg and risk of stillbirth is reassuring, given that iodine deficiency in pregnancy is prevalent in developed countries.
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Affiliation(s)
- Alexandra C Purdue-Smithe
- Division of Intramural Population Health Research, National Institutes of Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
| | - Tuija Männistö
- Northern Finland Laboratory Center NordLab, Oulu University Hospital, Oulu, Finland
| | - Elijah Reische
- Division of Intramural Population Health Research, National Institutes of Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
| | - Kurunthachalam Kannan
- Department of Pediatrics and Department of Environmental Medicine, New York University School of Medicine, New York, New York, USA
| | - Un-Jung Kim
- Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, Texas, USA
| | - Eila Suvanto
- Oulu University Hospital, Department of Children and Women and Oulu University Medical Faculty PEDEGO Research Unit, Medical Research Center, Oulu, Finland
| | - Heljä-Marja Surcel
- Biobank Borealis of Northern Finland, Oulu University Hospital, Oulu, Finland.,Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Mika Gissler
- Information Services Department, Finnish Institute of Health and Welfare, Helsinki, Finland.,Department of Neurobiology, Karolinska Institute, Stockholm, Sweden
| | - James L Mills
- Division of Intramural Population Health Research, National Institutes of Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
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Samson L, Hircsu I, Katko M, Bodor M, Gazdag A, Gazso AA, Kovacs B, Posta J, Balogh E, Mocsary P, Bhattoa HP, Nagy EV. Lower educational status interferes with maternal iodine intake during both pregnancy and lactation. Endocr Connect 2021; 10:742-749. [PMID: 34114967 PMCID: PMC8284948 DOI: 10.1530/ec-21-0166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/11/2021] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To investigate factors affecting conscious iodine intake among pregnant and lactating women in a rural area in Hungary. METHODS Pregnant women were studied and followed during lactation. Urinary and breast milk iodine concentration (UIC and MIC) were measured by inductively coupled plasma mass spectrometry. Potential interfering factors, including age, educational status and smoking were assessed. RESULTS During pregnancy and lactation, mild iodine deficiency was observed; median UIC were 66 and 49 µg/L, respectively. Educational status was found to be a strong determinant of both iodine nutrition and smoking status during pregnancy (P < 0.01 and P < 0.001) and lactation (P < 0.001 and P < 0.01). While smoking and non-smoking lactating mothers had similar concentrations of urinary iodine (median UIC: 47 and 51 µg/L, P = 0.95), the breast milk of smoking mothers contained less iodine (median MIC: 150 and 203 µg/L, P = 0.03). CONCLUSIONS Both low iodine intake and smoking contribute to the higher risk of iodine deficiency in women with lower educational status. In smokers, MIC is often low in spite of normal UIC, presumably due to the iodine transport blocking effect of the cigarette smoke towards breast milk; normal UIC may be misinterpreted as sufficient iodine supply towards the child. Antenatal health promotion strategies should focus on young women with lower educational status, even in regions where sufficient iodine intake has been achieved in non-pregnant adults.
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Affiliation(s)
- Laszlo Samson
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ildiko Hircsu
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Health Sciences, University of Debrecen, Debrecen, Hungary
| | - Monika Katko
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Miklos Bodor
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Annamaria Gazdag
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrea Anett Gazso
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Health Sciences, University of Debrecen, Debrecen, Hungary
| | - Bela Kovacs
- Institute of Food Science, University of Debrecen, Debrecen, Hungary
| | - Janos Posta
- Department of Forensic Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Eszter Balogh
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Peter Mocsary
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Harjit Pal Bhattoa
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Endre V Nagy
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Correspondence should be addressed to E V Nagy:
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Monaghan AM, Mulhern MS, McSorley EM, Strain JJ, Dyer M, van Wijngaarden E, Yeates AJ. Associations between maternal urinary iodine assessment, dietary iodine intakes and neurodevelopmental outcomes in the child: a systematic review. Thyroid Res 2021; 14:14. [PMID: 34099006 PMCID: PMC8182912 DOI: 10.1186/s13044-021-00105-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/20/2021] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE Mild to moderate iodine deficiency during pregnancy has been associated with adverse neurodevelopmental outcomes in offspring. Few research studies to date combine assessment of urinary iodine (UIC and/or ICr), biomarkers that best reflect dietary intake, with reported dietary intake of iodine rich foods in their assessment of iodine deficiency. Thus, a systematic review was conducted to incorporate both these important measures. DESIGN Using PRISMA guidelines, a comprehensive search was conducted in three electronic databases (EMBASE®, MedLine® and Web of Science®) from January 1970-March 2021. Quality assessment was undertaken using the Newcastle Ottawa Scale. Eligible studies included reported assessment of iodine status through urinary iodine (UIC and/or ICr) and/or dietary intake measures in pregnancy alongside neurodevelopmental outcomes measured in the children. Data extracted included study author, design, sample size, country, gestational age, child age at testing, cognitive tests, urinary iodine assessment (UIC in μg/L and/or ICr in μg/g), dietary iodine intake assessment and results of associations for the assessed cognitive outcomes. RESULTS Twelve studies were included with nine reporting women as mild-moderately iodine deficient based on World Health Organization (WHO) cut-offs for urinary iodine measurements < 150 μg/l, as the median UIC value in pregnant women. Only four of the nine studies reported a negative association with child cognitive outcomes based on deficient urinary iodine measurements. Five studies reported urinary iodine measurements and dietary intakes with four of these studies reporting a negative association of lower urinary iodine measurements and dietary iodine intakes with adverse offspring neurodevelopment. Milk was identified as the main dietary source of iodine in these studies. CONCLUSION The majority of studies classified pregnant women to be mild-moderately iodine deficient based on urinary iodine assessment (UIC and/or ICr) and/or dietary intakes, with subsequent offspring neurodevelopment implications identified. Although a considerable number of studies did not report an adverse association with neurodevelopmental outcomes, these findings are still supportive of ensuring adequate dietary iodine intakes and urinary iodine monitoring throughout pregnancy due to the important role iodine plays within foetal neurodevelopment. This review suggests that dietary intake data may indicate a stronger association with cognitive outcomes than urinary iodine measurements alone. The strength of this review distinguishes results based on cognitive outcome per urinary iodine assessment strategy (UIC and/or ICr) with dietary data. Future work is needed respecting the usefulness of urinary iodine assessment (UIC and/or ICr) as an indicator of deficiency whilst also taking account of dietary intakes.
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Affiliation(s)
- Anna M Monaghan
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, Northern Ireland
| | - Maria S Mulhern
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, Northern Ireland
| | - Emeir M McSorley
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, Northern Ireland
| | - J J Strain
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, Northern Ireland
| | - Matthew Dyer
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, Northern Ireland
| | - Edwin van Wijngaarden
- The Department of Community and Preventive Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Alison J Yeates
- Nutrition Innovation Centre for Food and Health, Ulster University, Coleraine, Northern Ireland.
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Keats EC, Oh C, Chau T, Khalifa DS, Imdad A, Bhutta ZA. Effects of vitamin and mineral supplementation during pregnancy on maternal, birth, child health and development outcomes in low- and middle-income countries: A systematic review. CAMPBELL SYSTEMATIC REVIEWS 2021; 17:e1127. [PMID: 37051178 PMCID: PMC8356361 DOI: 10.1002/cl2.1127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Background Almost two billion people who are deficient in vitamins and minerals are women and children in low- and middle-income countries (LMIC). These deficiencies are worsened during pregnancy due to increased energy and nutritional demands, causing adverse outcomes in mother and child. To reduce micronutrient deficiencies, several strategies have been implemented, including diet diversification, large-scale and targeted fortification, staple crop bio-fortification and micronutrient supplementation. Objectives To evaluate and summarize the available evidence on the effects of micronutrient supplementation during pregnancy in LMIC on maternal, fetal, child health and child development outcomes. This review will assess the impact of single micronutrient supplementation (calcium, vitamin A, iron, vitamin D, iodine, zinc, vitamin B12), iron-folic acid (IFA) supplementation, multiple micronutrient (MMN) supplementation, and lipid-based nutrient supplementation (LNS) during pregnancy. Search Methods We searched papers published from 1995 to 31 October 2019 (related programmes and good quality studies pre-1995 were limited) in CAB Abstracts, CINAHL, Cochrane Central Register of Controlled Trials, Embase, International Initiative for Impact Evaluations, LILACS, Medline, POPLINE, Web of Science, WHOLIS, ProQuest Dissertations & Theses Global, R4D, WHO International Clinical Trials Registry Platform. Non-indexed grey literature searches were conducted using Google, Google Scholar, and web pages of key international nutrition agencies. Selection Criteria We included randomized controlled trials (individual and cluster-randomized) and quasi-experimental studies that evaluated micronutrient supplementation in healthy, pregnant women of any age and parity living in a LMIC. LMIC were defined by the World Bank Group at the time of the search for this review. While the aim was to include healthy pregnant women, it is likely that these populations had one or more micronutrient deficiencies at baseline; women were not excluded on this basis. Data Collection and Analysis Two authors independently assessed studies for inclusion and risk of bias, and conducted data extraction. Data were matched to check for accuracy. Quality of evidence was assessed using the GRADE approach. Main Results A total of 314 papers across 72 studies (451,723 women) were eligible for inclusion, of which 64 studies (439,649 women) contributed to meta-analyses. Seven studies assessed iron-folic acid (IFA) supplementation versus folic acid; 34 studies assessed MMN vs. IFA; 4 studies assessed LNS vs. MMN; 13 evaluated iron; 13 assessed zinc; 9 evaluated vitamin A; 11 assessed vitamin D; and 6 assessed calcium. Several studies were eligible for inclusion in multiple types of supplementation. IFA compared to folic acid showed a large and significant (48%) reduction in the risk of maternal anaemia (average risk ratio (RR) 0.52, 95% CI 0.41 to 0.66; studies = 5; participants = 15,540; moderate-quality evidence). As well, IFA supplementation demonstrated a smaller but significant, 12% reduction in risk of low birthweight (LBW) babies (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). MMN supplementation was defined as any supplement that contained at least 3 micronutrients. Post-hoc analyses were conducted, where possible, comparing the differences in effect of MMN with 4+ components and MMN with 3 or 4 components. When compared to iron with or without FA, MMN supplementation reduced the risk of LBW by 15% (average RR 0.85, 95% CI 0.77 to 0.93; studies = 28; participants = 79,972); this effect was greater in MMN with >4 micronutrients (average RR 0.79, 95% CI 0.71 to 0.88; studies = 19; participants = 68,138 versus average RR 1.01, 95% CI 0.92 to 1.11; studies = 9; participants = 11,834). There was a small and significant reduction in the risk of stillbirths (average RR 0.91; 95% CI 0.86 to 0.98; studies = 22; participants = 96,772) and a small and significant effect on the risk of small-for-gestational age (SGA) (average RR 0.93; 95% CI 0.88 to 0.98; studies = 19; participants = 52,965). For stillbirths and SGA, the effects were greater among those provided MMN with 4+ micronutrients. Children whose mothers had been supplemented with MMN, compared to IFA, demonstrated a 16% reduced risk of diarrhea (average RR 0.84; 95% CI 0.76 to 0.92; studies = 4; participants = 3,142). LNS supplementation, compared to MMN, made no difference to any outcome; however, the evidence is limited. Iron supplementation, when compared to no iron or placebo, showed a large and significant effect on maternal anaemia, a reduction of 47% (average RR 0.53, 95% CI 0.43 to 0.65; studies = 6; participants = 15,737; moderate-quality evidence) and a small and significant effect on LBW (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). Zinc and vitamin A supplementation, each both compared to placebo, had no impact on any outcome examined with the exception of potentially improving serum/plasma zinc (mean difference (MD) 0.43 umol/L; 95% CI -0.04 to 0.89; studies = 5; participants = 1,202) and serum/plasma retinol (MD 0.13 umol/L; 95% CI -0.03 to 0.30; studies = 6; participants = 1,654), respectively. When compared to placebo, vitamin D supplementation may have reduced the risk of preterm births (average RR 0.64; 95% CI 0.40 to 1.04; studies = 7; participants = 1,262), though the upper CI just crosses the line of no effect. Similarly, calcium supplementation versus placebo may have improved rates of pre-eclampsia/eclampsia (average RR 0.45; 95% CI 0.19 to 1.06; studies = 4; participants = 9,616), though the upper CI just crosses 1. Authors' Conclusions The findings suggest that MMN and vitamin supplementation improve maternal and child health outcomes, including maternal anaemia, LBW, preterm birth, SGA, stillbirths, micronutrient deficiencies, and morbidities, including pre-eclampsia/eclampsia and diarrhea among children. MMN supplementation demonstrated a beneficial impact on the most number of outcomes. In addition, MMN with >4 micronutrients appeared to be more impactful than MMN with only 3 or 4 micronutrients included in the tablet. Very few studies conducted longitudinal analysis on longer-term health outcomes for the child, such as anthropometric measures and developmental outcomes; this may be an important area for future research. This review may provide some basis to guide continual discourse around replacing IFA supplementation with MMN along with the use of single micronutrient supplementation programs for specific outcomes.
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Affiliation(s)
- Emily C. Keats
- Centre for Global Child HealthThe Hospital for Sick ChildrenTorontoCanada
| | - Christina Oh
- Centre for Global Child HealthThe Hospital for Sick ChildrenTorontoCanada
| | - Tamara Chau
- Centre for Global Child HealthThe Hospital for Sick ChildrenTorontoCanada
| | - Dina S. Khalifa
- Centre for Global Child HealthThe Hospital for Sick ChildrenTorontoCanada
| | - Aamer Imdad
- PediatricsUpstate Medical University, SyracuseNew YorkUSA
| | - Zulfiqar A. Bhutta
- Centre for Global Child HealthThe Hospital for Sick ChildrenTorontoCanada
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Neven KY, Wang C, Janssen BG, Roels HA, Vanpoucke C, Ruttens A, Nawrot TS. Ambient air pollution exposure during the late gestational period is linked with lower placental iodine load in a Belgian birth cohort. ENVIRONMENT INTERNATIONAL 2021; 147:106334. [PMID: 33360673 PMCID: PMC7816215 DOI: 10.1016/j.envint.2020.106334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND Adequate intake of iodine is required for the production of thyroid hormones and contributes in pregnant women to a healthy brain development and growth in their offspring. To date, some evidence exists that fine particulate air pollution is linked with the fetal thyroid hormone homeostasis. However, possible effects of air pollutants on the placental iodine storage have not been investigated so far. OBJECTIVES We investigated the association between air pollution exposure to particulate matter with a diameter less than 2.5 µm (PM2.5), NO2, and black carbon and the placental iodine load. METHODS The current study is part of the ENVIRONAGE birth cohort and included 470 mother-newborn pairs. Iodine concentrations were measured in placental tissue. A high-resolution air pollution model was used to estimate the daily exposure to PM2.5, NO2, and black carbon over the entire pregnancy based on the maternal residential addresses. Distributed lag nonlinear models (DLNMs) were used to estimate gestational week-specific associations between placental iodine concentrations and the air pollutants to understand the impact of specific exposure windows. RESULTS PM2.5 showed a positive association with placental iodine concentration between the 16th and 22nd week of gestation. In contrast, a significant inverse association between PM2.5 and placental iodine concentration was observed in gestational weeks 29-35. The effect estimate, for a 5 µg/m3 increment in PM2.5 concentration, was the strongest at week 32 (β -0.11 µg/kg; 95%CI: -0.18 to -0.03). No associations were observed between placental iodine concentrations and NO2 or black carbon. Assuming causality, we estimated that placental iodine mediated 26% (-0.33 pmol/L; 95%CI: -0.70 to 0.04 pmol/L) of the estimated effect of a 5 µg/m3 increment in PM2.5 exposure on cord blood free thyroxine (FT4) concentrations. CONCLUSION In utero exposure to particulate matter during the third trimester of pregnancy is linked with a lower placental iodine load. Furthermore, the effect of air pollution on cord blood FT4 levels was partially mediated by the placental iodine load.
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Affiliation(s)
- Kristof Y Neven
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Congrong Wang
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Bram G Janssen
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Harry A Roels
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium; Louvain Centre for Toxicology and Applied Pharmacology, Université catholique de Louvain, Brussels, Belgium
| | | | - Ann Ruttens
- SD, Chemical, and Physical Health Risks, Sciensano, Tervuren, Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium; Department of Public Health and Primary Care, Leuven University, Leuven, Belgium.
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Hamada K, Mizokami T, Maruta T, Higashi K, Konishi K, Momotani N, Tajiri J. Thyroid Function of Infants Breastfed by Mothers with Graves Disease Treated with Inorganic Iodine: A Study of 100 Cases. J Endocr Soc 2021; 5:bvaa187. [PMID: 33381674 PMCID: PMC7757433 DOI: 10.1210/jendso/bvaa187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Indexed: 11/19/2022] Open
Abstract
Context We previously reported that inorganic iodine therapy in lactating women with Graves disease (GD) did not affect the thyroid function in 25 of 26 infants despite their exposure to excess iodine via breast milk. Objective To further assess thyroid function in infants nursed by mothers with GD treated with inorganic iodine. Design Case series Setting Tajiri Thyroid Clinic, Japan Participants One hundred infants of lactating mothers with GD treated with potassium iodide (KI) for thyrotoxicosis Main Outcome Measures Infant blood thyrotropin (TSH) and free thyroxine (FT4) levels were measured by the filter paper method. Subclinical hypothyroidism was defined as TSH ≥10 μIU/mL and ≥5 μIU/mL in infants aged <6 and ≥6 months, respectively. Results Overall, 210 blood samples were obtained from 100 infants. The median infant age was 5 (range, 0-23) months; median maternal KI dose, 50 (4-100) mg/day; median blood TSH level, 2.7 (0.1-12.3) μIU/mL; and median blood FT4 level, 1.04 (0.58-1.94) ng/dL. Blood TSH level was normal in 88/100 infants. Twelve infants had subclinical hypothyroidism; among them, blood TSH levels normalized after maternal KI withdrawal or stopping breastfeeding in 3 infants. In 7 infants, blood TSH levels normalized during KI administration without stopping breastfeeding. Two infants could not be followed up. Conclusion In Japan, inorganic iodine therapy for lactating women with GD did not affect thyroid function in most of the infants. Approximately 10% of infants had mild subclinical hypothyroidism, but blood TSH level normalized during continued or after discontinuing iodine exposure in all followed up infants.
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Affiliation(s)
| | | | | | | | - Kaoru Konishi
- Division of Newborn Screening, Tokyo Health Service Association, Tokyo, Japan
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ŞİMŞEK H, KARAAĞAÇ Y, TUNÇER E, YARDIMCI H. Gebelikte Folik Asit, B12 Vitamini, D Vitamini ve İyot Destekleri Kullanmak Gerekli Midir?: Olası Riskler. KAHRAMANMARAŞ SÜTÇÜ İMAM ÜNIVERSITESI TIP FAKÜLTESI DERGISI 2021. [DOI: 10.17517/ksutfd.832401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Iodine knowledge is associated with iodine status in Portuguese pregnant women: results from the IoMum cohort study. Br J Nutr 2021; 126:1331-1339. [PMID: 33461643 DOI: 10.1017/s0007114521000155] [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] [Indexed: 11/07/2022]
Abstract
Lack of knowledge about iodine has been suggested as a risk factor for iodine deficiency in pregnant women, but no studies have addressed this issue in Portugal. So, the aim of this study was to investigate iodine knowledge among Portuguese pregnant women and its association with iodine status. IoMum, a prospective observational study, included 485 pregnant women recruited at Centro Hospitalar e Universitário de S. João, Porto, between the 10th and 13th gestational weeks. Partial scores for knowledge on iodine importance, on iodine food sources or on iodised salt were obtained through the application of a structured questionnaire. Then, a total iodine knowledge score was calculated and grouped into low, medium and high knowledge categories. Urinary iodine concentration (UIC) was measured in spot urine samples by inductively coupled plasma MS. Of the pregnant women, 54 % correctly recognised iodine as important to neurocognitive development, 32 % were unable to identify any iodine-rich food and 71 % presented lack of knowledge regarding iodised salt. Of the women, 61 % had a medium total score of iodine knowledge. Knowledge on iodine importance during pregnancy was positively associated with iodine supplementation and also with UIC. Nevertheless, median UIC in women who correctly recognised the importance of iodine was below the cut-off for adequacy in pregnancy (150 µg/l). In conclusion, knowledge on iodine importance is positively associated with iodine status. Despite this, recognising iodine importance during pregnancy may not be sufficient to ensure iodine adequacy. Literacy-promoting actions are urgently needed to improve iodine status in pregnancy.
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Aakre I, Morseth MS, Dahl L, Henjum S, Kjellevold M, Moe V, Smith L, Markhus MW. Iodine status during pregnancy and at 6 weeks, 6, 12 and 18 months post-partum. MATERNAL & CHILD NUTRITION 2021; 17:e13050. [PMID: 32602197 PMCID: PMC7729798 DOI: 10.1111/mcn.13050] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 05/20/2020] [Accepted: 06/02/2020] [Indexed: 11/30/2022]
Abstract
Iodine deficiency during pregnancy and in the post-partum period may lead to impaired child development. Our aim is to describe iodine status longitudinally in women from pregnancy until 18 months post-partum. Furthermore, we explore whether iodine status is associated with dietary intake, iodine-containing supplement use and breastfeeding status from pregnancy until 18 months post-partum. We also assess the correlation between maternal iodine status 18 months post-partum and child iodine status at 18 months of age. Iodine status was measured by urinary iodine concentration (UIC) during pregnancy (n = 1,004), 6 weeks post-partum (n = 915), 6 months post-partum (n = 849), 12 months post-partum (n = 733) and 18 months post-partum (n = 714). The toddlers' UIC was assessed at 18 months of age (n = 416). Demographic variables and dietary data (food frequency questionnaire) were collected during pregnancy, and dietary data and breastfeeding practices were collected at all time points post-partum. We found that iodine status was insufficient in both pregnant and post-partum women. The UIC was at its lowermost 6 weeks post-partum and gradually improved with increasing time post-partum. Intake of milk and use of iodine-containing supplements significantly increased the odds of having a UIC above 100 μg/L. Neither the mothers' UIC, vegetarian practice, nor exclusion of milk and dairy products were associated with the toddlers UIC 18 months post-partum. Women who exclude milk and dairy products from their diets and/or do not use iodine-containing supplements may be at risk of iodine deficiency. The women possibly also have an increased risk of thyroid dysfunction and for conceiving children with nonoptimal developmental status.
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Affiliation(s)
- Inger Aakre
- Department of Seafood, Nutrition and Environmental StateInstitute of Marine ResearchBergenNorway
| | - Marianne Sandsmark Morseth
- Department of Nursing and Health Promotion, Faculty of Health SciencesOsloMet—Oslo Metropolitan UniversityOsloNorway
| | - Lisbeth Dahl
- Department of Seafood, Nutrition and Environmental StateInstitute of Marine ResearchBergenNorway
| | - Sigrun Henjum
- Department of Nursing and Health Promotion, Faculty of Health SciencesOsloMet—Oslo Metropolitan UniversityOsloNorway
| | - Marian Kjellevold
- Department of Seafood, Nutrition and Environmental StateInstitute of Marine ResearchBergenNorway
| | - Vibeke Moe
- Department of PsychologyUniversity of OsloOsloNorway
| | - Lars Smith
- Department of PsychologyUniversity of OsloOsloNorway
| | - Maria Wik Markhus
- Department of Seafood, Nutrition and Environmental StateInstitute of Marine ResearchBergenNorway
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Lee SY. Editorial: Consequences of Iodine Deficiency in Pregnancy. Front Endocrinol (Lausanne) 2021; 12:740239. [PMID: 34394012 PMCID: PMC8355982 DOI: 10.3389/fendo.2021.740239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 07/16/2021] [Indexed: 11/13/2022] Open
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Nazeri P, Tahmasebinejad Z, Hedayati M, Mirmiran P, Azizi F. Is breast milk iodine concentration an influential factor in growth- and obesity-related hormones and infants' growth parameters? MATERNAL & CHILD NUTRITION 2021; 17:e13078. [PMID: 32990418 PMCID: PMC7729768 DOI: 10.1111/mcn.13078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 07/27/2020] [Accepted: 09/02/2020] [Indexed: 01/22/2023]
Abstract
Iodine, a key constituent of thyroid hormones, plays an indirect role in prenatal and postnatal growth. This study aimed to investigate whether breast milk iodine concentration (BMIC) is associated with growth- and obesity-related hormones and subsequently the infants' anthropometric measures. In present study conducted in Tehran (Iran), 94 lactating mothers and healthy infants who were exclusively breastfed were included. Concentrations of iodine, insulin-like growth factor-1 (IGF-1), adiponectin (AD) and leptin (LP) were measured in breast milk samples collected during 3- to 5-day postpartum. Anthropometric measures of infants were assessed at 6 months of life, and age- and sex-specific z-score values were calculated using the World Health Organization growth standards. The median (interquartile range) iodine, IGF-1, AD and LP concentrations were 232.5 (157.5-296.0) μg L-1 , 15.7 (11.9-21.1) ng ml-1 , 13.2 (5.1-29.8) mg L-1 and 1.16 (0.86-1.70) ng ml-1 in breast milk, respectively. No significant correlations were found between BMIC and IGF-1, AD and LP concentrations during the first few days postpartum. In adjusted regression model, BMIC was positively associated with weight-for-length z score of infants. In the presence of IGF-1, AD or LP, the coefficients of BMIC for weight-for-length z score of infants were β = .003 (P = .021), β = .002 (P = .028) or β = .003 (P = .013), respectively. No other anthropometric measurements were associated with iodine or growth- and obesity-related hormones in breast milk. Our findings indicate that BMIC is a potential contributor to infants' growth status, independent of IGF-1, AD or LP concentrations in breast milk. The underlying mechanisms remain to be elucidated.
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Affiliation(s)
- Pantea Nazeri
- Family Health Institute, Breastfeeding Research CenterTehran University of Medical SciencesTehranIran
| | - Zhale Tahmasebinejad
- Nutrition and Endocrine Research Center, Research Institute for Endocrine SciencesShahid Beheshti University of Medical SciencesTehranIran
| | - Mehdi Hedayati
- Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine SciencesShahid Beheshti University of Medical SciencesTehranIran
| | - Parvin Mirmiran
- Nutrition and Endocrine Research Center, Research Institute for Endocrine SciencesShahid Beheshti University of Medical SciencesTehranIran
- Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research InstituteShahid Beheshti University of Medical SciencesTehranIran
| | - Fereidoun Azizi
- Endocrine Research Center, Research Institute for Endocrine SciencesShahid Beheshti University of Medical SciencesTehranIran
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Pozo-Palacios J, García-Díaz G, Cruz F, Porras F, Heras J, Cano-Pérez E. Spatial Distribution of Congenital Disorders Diagnosed by the Newborn Screening Program in Ecuador. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2021. [DOI: 10.1590/2326-4594-jiems-2020-0016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Affiliation(s)
- Juan Pozo-Palacios
- Ministerio de Salud Pública, Ecuador; Universidad de Cuenca, Ecuador; Ministerio de Salud Pública, Ecuador
| | | | | | | | | | - Eder Cano-Pérez
- Universidad de Cartagena, Colombia; Universidad Simón Bolívar, Colombia
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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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Neven KY, Cox B, Vrijens K, Plusquin M, Roels HA, Ruttens A, Nawrot TS. Determinants of placental iodine concentrations in a mild-to-moderate iodine-deficient population: an ENVIRONAGE cohort study. J Transl Med 2020; 18:426. [PMID: 33172470 PMCID: PMC7654607 DOI: 10.1186/s12967-020-02601-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 11/01/2020] [Indexed: 01/08/2023] Open
Abstract
Background Iodine is an essential trace element for the production of thyroid hormones, and plays a key role during the gestational period for optimal foetal growth and (neuro-)development. To this day, iodine deficiency remains a global burden. Previous studies indicate that the placenta can store iodine in a concentration-dependent manner and serve as a long-term storage supply, but studies on the determinants of long-term placental iodine load are limited. Methods The placental iodine concentrations were determined for 462 mother-neonate pairs from the ENVIRONAGE birth cohort (Limburg, Belgium). Sociodemographic and clinical variables were obtained from questionnaires and medical files. Determinants of placental iodine concentration were identified using stepwise multiple regression procedures (p value < 0.15). The biological significance of our findings was investigated by measuring the plasma thyroid hormones in maternal and cord blood of 378 participants. Results A higher pre-pregnancy BMI, higher gestational weight gain, and alcohol consumption during pregnancy were linked with lower placental iodine storage. Multi-vitamin supplementation during pregnancy and longer gestation were associated with higher levels of placental iodine. Children born during the winter period had on average higher placental iodine levels. Besides, we found a significant positive time trend for placental iodine load over the study period 2013 to 2017. Lastly, we observed positive associations of both the maternal and cord plasma thyroxine concentrations with placental iodine load, emphasizing their biological link. Conclusions This study identified some determinants likely presenting a risk of reduced iodine storage during the gestational period of life. Future studies should elucidate the effects of lower placental iodine load on neonatal health, and health later in life.
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Affiliation(s)
- Kristof Y Neven
- Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590, Diepenbeek, Belgium.
| | - Bianca Cox
- Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590, Diepenbeek, Belgium
| | - Karen Vrijens
- Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590, Diepenbeek, Belgium
| | - Michelle Plusquin
- Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590, Diepenbeek, Belgium
| | - Harry A Roels
- Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590, Diepenbeek, Belgium.,Louvain Centre for Toxicology and Applied Pharmacology, Université Catholique de Louvain, E. Mounierlaan 53, 1200, Brussels, Belgium
| | - Ann Ruttens
- Sciensano, SD Chemical, and Physical Health Risks, Leuvensesteenweg 17, 3080, Tervuren, Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590, Diepenbeek, Belgium.,Department of Public Health & Primary Care, Leuven University, Kapucijnenvoer 35, 3000, Leuven, Belgium
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35
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Brito AF. Assessing the potential of milk iodine intake to mitigate iodine deficiency in pregnant women of the United States via supplementation of Ascophyllum nodosum meal to dairy cows: A sensitivity analysis. J Dairy Sci 2020; 103:6798-6809. [PMID: 32505413 DOI: 10.3168/jds.2019-17429] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 04/01/2020] [Indexed: 11/19/2022]
Abstract
The brown seaweed Ascophyllum nodosum is known to bioaccumulate iodine (I). Previous research showed a linear relationship between A. nodosum meal (ASCO) intake and milk I concentration in dairy cows. Thus, improving milk I concentration by supplementation of ASCO to dairy cows may be a compelling strategy to naturally boost I intake in humans. A sensitivity analysis was conducted to gain insights regarding how different milk I intakes affect the I status of pregnant women relative to the United States Institute of Medicine (US IOM) recommended dietary allowance (RDA; 220 µg/d) and the World Health Organization (WHO) recommended nutrient intake (RNI; 250 µg/d) for I. Four studies in which dairy cows received various amounts of ASCO generated the milk I data set used in the sensitivity analysis. The annual per capita consumption of 2% reduced-fat milk in the United States, converted to daily intake (i.e., 0.26 cup; 1 cup = 236.6 mL), was used as the actual milk intake in the simulations. Five additional milk intake scenarios (2, 3, 4, and 5 times the actual per capita milk consumption and the 3 cups-equivalent recommended by the 2015-2020 Dietary Guidelines for American were also included in the sensitivity analysis with varying milk I concentrations (180, 765, and 483 µg/L). The 180, 765, and 483 µg/L values are milk I concentrations derived from cows not receiving ASCO or fed various amounts of ASCO in the diet or a single level (113 g/d) during the grazing season, respectively. With the actual United States milk per capita consumption of 0.26 cup/d and milk I concentrations of 180, 765, and 483 µg/L, 5.09, 21.7, and 13.6% of the RDA for I for pregnant women were met based on the US IOM, respectively. Similarly, 4.48, 19, and 12% of the RNI for I advised by the WHO was achieved with intake of 0.26 cup/d of milk containing I concentrations of 180, 765, and 483 µg/L, respectively. When 3 cups/d was included in the simulations, 58.2, 247, and 156% (US IOM), and 51.2, 217, and 137% (WHO) of the RDA or RNI for I required by gestating women was satisfied with milk I concentrations of 180, 765, and 483 µg/L, respectively. A regression analysis between I intake and milk I concentration revealed that 103 g/d of ASCO in the diet of dairy cows reached the maximum 500 µg/L threshold of I in milk recommended by the European Food Society Authority. Overall, milk from dairy cows fed ASCO can prevent I deficiency in pregnant women, but the amount of ASCO fed to cows needs to be fine-tuned to avoid excess I in milk. Further research is required to better understand the interactions between goitrogenic compounds from forages and concentrates and milk I concentration in cows fed ASCO. Research to evaluate the concentration of I in retail organic milk should be also conducted because of the high prevalence of ASCO fed in organic dairies in the United States.
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Affiliation(s)
- A F Brito
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham 03824.
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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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Snart CJP, Threapleton DE, Keeble C, Taylor E, Waiblinger D, Reid S, Alwan NA, Mason D, Azad R, Cade JE, Simpson NAB, Meadows S, McKillion A, Santorelli G, Waterman AH, Zimmermann M, Stewart PM, Wright J, Mon-Williams M, Greenwood DC, Hardie LJ. Maternal iodine status, intrauterine growth, birth outcomes and congenital anomalies in a UK birth cohort. BMC Med 2020; 18:132. [PMID: 32522280 PMCID: PMC7288513 DOI: 10.1186/s12916-020-01602-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/21/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Severe iodine insufficiency in pregnancy has significant consequences, but there is inadequate evidence to indicate what constitutes mild or moderate insufficiency, in terms of observed detrimental effects on pregnancy or birth outcomes. A limited number of studies have examined iodine status and birth outcomes, finding inconsistent evidence for specific outcomes. METHODS Maternal iodine status was estimated from spot urine samples collected at 26-28 weeks' gestation from 6971 mothers in the Born in Bradford birth cohort. Associations with outcomes were examined for both urinary iodine concentration (UIC) and iodine-to-creatinine ratio (I:Cr). Outcomes assessed included customised birthweight (primary outcome), birthweight, small for gestational age (SGA), low birthweight, head circumference and APGAR score. RESULTS There was a small positive association between I:Cr and birthweight in adjusted analyses. For a typical participant, the predicted birthweight centile at the 25th percentile of I:Cr (59 μg/g) was 2.7 percentage points lower than that at the 75th percentile of I:Cr (121 μg/g) (99% confidence interval (CI) 0.8 to 4.6), birthweight was predicted to be 41 g lower (99% CI 13 to 69) and the predicted probability of SGA was 1.9 percentage points higher (99% CI 0.0 to 3.7). There was no evidence of associations using UIC or other birth outcomes, including stillbirth, preterm birth, ultrasound growth measures or congenital anomalies. CONCLUSION Lower maternal iodine status was associated with lower birthweight and greater probability of SGA. Whilst small, the effect size for lower iodine on birthweight is comparable to environmental tobacco smoke exposure. Iodine insufficiency is avoidable, and strategies to avoid deficiency in women of reproductive age should be considered. TRIAL REGISTRATION ClinicalTrials.gov NCT03552341. Registered on June 11, 2018.
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Affiliation(s)
- Charles Jonathan Peter Snart
- Leeds Institute of Cardiovascular & Metabolic Medicine, LIGHT Laboratories, School of Medicine, University of Leeds, Leeds, LS2 9JT, UK
| | - Diane Erin Threapleton
- Leeds Institute of Cardiovascular & Metabolic Medicine, LIGHT Laboratories, School of Medicine, University of Leeds, Leeds, LS2 9JT, UK
| | - Claire Keeble
- Leeds Institute for Data Analytics, University of Leeds, Leeds, LS2 9JT, UK
| | - Elizabeth Taylor
- Leeds Institute of Cardiovascular & Metabolic Medicine, LIGHT Laboratories, School of Medicine, University of Leeds, Leeds, LS2 9JT, UK
| | - Dagmar Waiblinger
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, BD9 6RJ, UK
| | - Stephen Reid
- Earth Surface Science Institute, School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | - Nisreen A Alwan
- School of Primary Care and Population Sciences, Faculty of Medicine, Southampton General Hospital, University of Southampton, Southampton, SO16 6YD, UK.,NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Dan Mason
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, BD9 6RJ, UK
| | - Rafaq Azad
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, BD9 6RJ, UK
| | - Janet Elizabeth Cade
- Nutritional Epidemiology Group, School of Food Science & Nutrition, University of Leeds, Leeds, LS2 9JT, UK
| | - Nigel A B Simpson
- Division of Women's and Children's Health, School of Medicine, University of Leeds, Leeds, LS2 9JT, UK
| | - Sarah Meadows
- Elsie Widdowson Laboratory, University of Cambridge, Cambridge, CB1 9NL, UK.,NIHR Nutritional Biomarker Laboratory, MRC Epidemiology Unit, University of Cambridge, Clifford Allbutt Building, Hills Road, Cambridge, CB2 0AH, UK
| | - Amanda McKillion
- Elsie Widdowson Laboratory, University of Cambridge, Cambridge, CB1 9NL, UK.,NIHR Nutritional Biomarker Laboratory, MRC Epidemiology Unit, University of Cambridge, Clifford Allbutt Building, Hills Road, Cambridge, CB2 0AH, UK
| | - Gillian Santorelli
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, BD9 6RJ, UK
| | | | - Michael Zimmermann
- Laboratory for Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, 8092, Zürich, Switzerland
| | - Paul M Stewart
- Faculty of Medicine and Health, University of Leeds, Leeds, LS2 9JT, UK
| | - John Wright
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, BD9 6RJ, UK
| | | | - Darren Charles Greenwood
- Leeds Institute of Cardiovascular & Metabolic Medicine, LIGHT Laboratories, School of Medicine, University of Leeds, Leeds, LS2 9JT, UK. .,Leeds Institute for Data Analytics, University of Leeds, Leeds, LS2 9JT, UK.
| | - Laura J Hardie
- Leeds Institute of Cardiovascular & Metabolic Medicine, LIGHT Laboratories, School of Medicine, University of Leeds, Leeds, LS2 9JT, UK.
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Nazeri P, Shab-Bidar S, Pearce EN, Shariat M. Thyroglobulin Concentration and Maternal Iodine Status During Pregnancy: A Systematic Review and Meta-Analysis. Thyroid 2020; 30:767-779. [PMID: 31910106 DOI: 10.1089/thy.2019.0712] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background: Literature to date has been inconclusive regarding the value of thyroglobulin (Tg) as a marker of iodine status in pregnant women. This systematic review and meta-analysis is one of the first to assess whether Tg concentration accurately reflects iodine status among pregnant women. Methods: We searched MEDLINE, the Web of Science, the Cochrane Library, Scopus, and other relevant databases to identify relevant studies published in the English language, between January 1988 and December 2018. The criteria for study inclusion in the systematic review were human studies, healthy pregnant women as participants, and available data for maternal urinary iodine concentration (UIC) and Tg level. Each study was assessed for quality and risk of bias. The pooled mean Tg values, and 95% confidence intervals were estimated in a population of women with UIC <150 and UIC ≥150 μg/L during pregnancy. Potential linear or nonlinear dose-response associations between maternal UIC and Tg concentration were examined. Results: Of 814 identified studies, 25 were eligible for inclusion in the meta-analysis. Studies included were conducted in Africa, Asia, Europe, South America, and the Oceania. The pooled mean (95% confidence interval [CI]) Tg concentration in iodine-deficient pregnant women was higher than that in iodine-sufficient pregnant women (10.73 μg/L [5.65-15.82] vs. 7.34 μg/L [2.20-12.47]); a comparison of the 95% CI showed that none of these values was significantly different. No significant differences were observed in Tg concentration between the two groups in each trimester of pregnancy. Dose-response meta-analyses revealed a significant nonlinear association between maternal UIC and Tg concentration during pregnancy. Among populations of pregnant women, an inverse association was found between UIC values <100 μg/L and Tg concentration (p-linearity = 0.007; p-nonlinearity = 0.027); however, higher values of UIC were not associated with Tg concentration. Conclusions: Our meta-analysis showed that Tg concentration can be a sensitive indicator of iodine deficiency, specifically in populations of pregnant women with median UIC <100 μg/L. Further studies are warranted to determine the sensitivity of Tg at different degrees of iodine deficiency during pregnancy.
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Affiliation(s)
- Pantea Nazeri
- Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Sakineh Shab-Bidar
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Mamak Shariat
- Family Health Institute, Maternal, Fetal and Neonatal Research Center, Tehran University of Medical Sciences, Tehran, Iran
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Abstract
Iodine deficiency during pregnancy is an important global public health issue and the leading preventable cause of neurodevelopmental impairments worldwide. The effects of severe iodine deficiency during pregnancy, including adverse obstetric outcomes and decreased child intelligence quotient, have been clearly established. However, the effects of mild-to-moderate deficiency remain less well understood. Pregnant and lactating women have higher iodine requirements than other adults; intakes of 220 to 250 µg/d in pregnancy and 250 to 290 µg/d in lactation. In this article, we describe iodine metabolism, iodine requirements in pregnancy and lactation, the effects of both iodine deficiency and excessive iodine intakes in pregnancy, and the efficacy of iodine supplementation.
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40
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Petersen E, Thorisdottir B, Thorsdottir I, Gunnlaugsson G, Arohonka P, Erlund I, Gunnarsdottir I. Iodine status of breastfed infants and their mothers' breast milk iodine concentration. MATERNAL AND CHILD NUTRITION 2020; 16:e12993. [PMID: 32162412 PMCID: PMC7296790 DOI: 10.1111/mcn.12993] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 12/26/2022]
Abstract
Iodine is an essential nutrient for growth and development during infancy. Data on iodine status of exclusively (EBF) and partially breastfed (PBF) infants as well as breast milk iodine concentration (BMIC) are scarce. We aimed to assess (a) infant iodine nutrition at the age of 5.5 months by measuring urinary iodine concentration (UIC) in EBF (n = 32) and PBF (n = 28) infants and (b) mothers' breast milk iodine concentration (n = 57). Sixty mother–infant pairs from three primary health care centres in Reykjavik and vicinities provided urine and breast milk samples for iodine analysis and information on mothers' habitual diet. The mother–infant pairs were participants of the IceAge2 study, which focuses on factors contributing to infant growth and development, including body composition and breast‐milk energy content. The median (25th–75th percentiles) UIC was 152 (79–239) μg/L, with no significant difference between EBF and PBF infants. The estimated median iodine intake ranged from 52 to 86 μg/day, based on urinary data (assuming an average urine volume of 300–500 ml/day and UIC from the present study). The median (25th–75th percentiles) BMIC was 84 (48–114) μg/L. It is difficult to conclude whether iodine status is adequate in the present study, as no ranges for median UIC reflecting optimal iodine nutrition exist for infants. However, the results add important information to the relatively sparse literature on UIC, BMIC, and iodine intake of breastfed infants.
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Affiliation(s)
- Erna Petersen
- Department of Clinical Nutrition, Landspitali University Hospital, Reykjavik, Iceland.,Unit for Nutrition Research, Faculty of Food Science and Nutrition, Landspitali University Hospital, University of Iceland, Reykjavik, Iceland
| | - Birna Thorisdottir
- Unit for Nutrition Research, Faculty of Food Science and Nutrition, Landspitali University Hospital, University of Iceland, Reykjavik, Iceland
| | - Inga Thorsdottir
- School of Health Sciences, University of Iceland, Reykjavik, Iceland
| | - Geir Gunnlaugsson
- Faculty of Sociology, Anthropology and Folkloristics, School of Social Sciences, University of Iceland, Reykjavik, Iceland
| | - Petra Arohonka
- Forensic Toxicology Unit, Biochemistry Laboratory, Finnish Institute for Health and Welfare (THL), Helsinki, Finland
| | - Iris Erlund
- Forensic Toxicology Unit, Biochemistry Laboratory, Finnish Institute for Health and Welfare (THL), Helsinki, Finland
| | - Ingibjörg Gunnarsdottir
- Department of Clinical Nutrition, Landspitali University Hospital, Reykjavik, Iceland.,Unit for Nutrition Research, Faculty of Food Science and Nutrition, Landspitali University Hospital, University of Iceland, Reykjavik, Iceland
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Etemadi A, Amouzegar A, Mehran L, Tohidi M, Azizi F, Moradi K, Delshad H. Isolated Hypothyroxinemia in Iranian Pregnant Women, the Role of Iodine Deficiency: A Population-Based Cross-Sectional Study. Thyroid 2020; 30:262-269. [PMID: 31724489 DOI: 10.1089/thy.2019.0047] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Background: Thyroid disorders such as subclinical hypothyroidism and isolated maternal hypothyroxinemia are understudied in pregnant women, despite their possible adverse effects on the health of mother and child. Also, the role of iodine deficiency in developing such disorders has not yet been fully understood. Methods: The present national population-based cross-sectional study was conducted on 1080 randomly recruited pregnant women, aged 20-40 from 12 provinces of Iran from 2013 to 2014. Serum concentrations of thyrotropin, T4, thyroid peroxidase antibody (TPOAb), and triiodothyronine (T3) resin uptake values were measured in fasting blood samples, and urinary iodine concentration (UIC) was measured in three separate urine samples. Multinomial logistic regression was run to analyze the possible risk factors regarding thyroid disorders. To clarify the role of iodine in thyroid status specifically, the determinants of UIC and its correlations with thyroid function tests were investigated independently and through subgroup analysis. Results: Isolated hypothyroxinemia was the most common thyroid disorder (9.9%), followed by subclinical hypothyroidism (8%). In comparison to euthyroid pregnant women, isolated hypothyroxinemia was more likely in pregnant women older than 30 years (odds ratio [OR] = 1.6), in the second and the third trimesters (OR = 2.62 and 2.12 respectively), with history of multiparity (OR = 1.72), residing in rural areas (OR = 1.57) and in the capital province of the country (OR = 3.3). Subclinical hypothyroidism was more likely in TPOAb positive pregnant women (OR = 2.56). All the mentioned ORs were statistically significant (p < 0.05). The UIC did not correlate significantly with any of the thyroid function tests in the study population. Subgroup analysis showed a significant correlation between UIC and T4 in pregnant women with subclinical hypothyroidism (p < 0.05). Conclusion: Isolated maternal hypothyroxinemia was the most prevalent thyroid disorder in Iranian pregnant women and its associated risk factors were identified. Although the calculated prevalence of thyroid disorders was expected in a moderately iodine deficient setting, no correlations between UICs and thyroid function tests were found at the individual level. The contribution of iodine deficiency to thyroid condition for each pregnant woman may be more evident in pregnant women with certain thyroid disorders or those with long-term iodine deficiency.
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Affiliation(s)
- Ali Etemadi
- Endocrine Research Center; Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atieh Amouzegar
- Endocrine Research Center; Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ladan Mehran
- Endocrine Research Center; Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Tohidi
- Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fereidoun Azizi
- Endocrine Research Center; Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kamyar Moradi
- Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Student's Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Delshad
- Endocrine Research Center; Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Abstract
Iodine is an essential trace element, necessary for the production of thyroid hormones, which play a key role in optimal foetal growth and (neuro-) development. To date, iodine deficiency remains a health burden in many countries. We investigated the variability of placental iodine concentrations within and between individuals. We used 20 mother-neonate pairs from the ENVIRONAGE birth cohort, took samples at three standardized locations of the placentas, pooled and digested them, and determined the iodine concentrations using an ICP-MS method as an alternative for the Sandell-Kolthoff method. The variability between and within the three sample regions was calculated using the intra-class correlation coefficient (ICC) from the variance components of mixed models. With the Friedman test, the differences between placental biopsies were assessed. The ICC showed a higher between-placenta (68.6%) than within-placenta (31.4%) variability. Subsequently, we used our optimized method to determine iodine concentrations in 498 mother-neonate pairs, which averaged 26.1 μg/kg. For 96 mothers, the urinary iodine concentrations were also determined, which showed no correlation with the placental iodine storage, as was expected. Future studies are necessary to explore the effects of these placental iodine concentrations in relation to health outcomes of mother and child at birth and later in life.
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Bilal MY, Dambaeva S, Brownstein D, Kwak-Kim J, Gilman-Sachs A, Beaman KD. Iodide Transporters in the Endometrium: A Potential Diagnostic Marker for Women with Recurrent Pregnancy Failures. Med Princ Pract 2020; 29:412-421. [PMID: 32353856 PMCID: PMC7511676 DOI: 10.1159/000508309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 04/22/2020] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE The element iodine is an essential nutrient utilized by the thyroid glands, and deficiency of this element has been linked to reproductive failures. Iodide transporters are also present in reproductive tissues and cells of embryonic origin such as the endometrium and trophoblasts, respectively. The aim of this study is to understand if levels of iodide transporters are linked to pregnancy outcomes. SUBJECTS AND METHODS RNA derived from endometrial biopsies from controls or women with recurrent reproductive failures was analyzed utilizing RT-PCR and targeted RNASeq. RESULTS When compared to controls, women with 2 or more reproductive failures had a significant increase (>5 fold) in mRNA levels of the iodine transporters NIS and PENDRIN, but not thyroglobulin when probed vis RT-PCR. Targeted RNASeq analysis confirmed these findings when another group of patients were analyzed. CONCLUSION These findings suggest possible abnormal iodine metabolism and a deficiency of iodine in endometrial tissues from some of the women with reproductive failures. We hypothesize from these findings that inorganic iodide and/or iodine is required for optimal cellular function in reproductive tissues, and that iodide transporters may potentially be used as a marker for infertility or for probing potential localized iodine deficiency that may not present in a typical thyroid panel analysis.
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Affiliation(s)
- Mahmood Y. Bilal
- aClinical Immunology Laboratory, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
- bDepartment of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
- *Kenneth D. Beaman, Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064 (USA),
| | - Svetlana Dambaeva
- aClinical Immunology Laboratory, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
- bDepartment of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | | | - Joanne Kwak-Kim
- bDepartment of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
- dDepartment of Obstetrics and Gynecology, Rosalind Franklin University Health System, Vernon Hills, Illinois, USA
| | - Alice Gilman-Sachs
- aClinical Immunology Laboratory, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
- bDepartment of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Kenneth D. Beaman
- aClinical Immunology Laboratory, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
- bDepartment of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
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The Joint Role of Thyroid Function and Iodine Status on Risk of Preterm Birth and Small for Gestational Age: A Population-Based Nested Case-Control Study of Finnish Women. Nutrients 2019; 11:nu11112573. [PMID: 31731400 PMCID: PMC6893669 DOI: 10.3390/nu11112573] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 11/17/2022] Open
Abstract
Normal maternal thyroid function during pregnancy is essential for fetal development and depends upon an adequate supply of iodine. Little is known about how iodine status is associated with preterm birth and small for gestational age (SGA) in mildly iodine insufficient populations. Our objective was to evaluate associations of early pregnancy serum iodine, thyroglobulin (Tg), and thyroid-stimulating hormone (TSH) with odds of preterm birth and SGA in a prospective, population-based, nested case-control study from all births in Finland (2012–2013). Cases of preterm birth (n = 208) and SGA (n = 209) were randomly chosen from among all singleton births. Controls were randomly chosen from among singleton births that were not preterm (n = 242) or SGA (n = 241) infants during the same time period. Women provided blood samples at 10–14 weeks’ gestation for serum iodide, Tg and TSH measurement. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for preterm birth and SGA. Each log-unit increase in serum iodide was associated with higher odds of preterm birth (adjusted OR = 1.19, 95% CI = 1.02–1.40), but was not associated with SGA (adjusted OR = 1.01, 95% CI = 0.86–1.18). Tg was not associated with preterm birth (OR per 1 log-unit increase = 0.87, 95% CI = 0.73–1.05), but was inversely associated with SGA (OR per log-unit increase = 0.78, 95% CI = 0.65–0.94). Neither high nor low TSH (versus normal) were associated with either outcome. These findings suggest that among Finnish women, iodine status is not related to SGA, but higher serum iodide may be positively associated with preterm birth.
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Businge CB, Longo-Mbenza B, Kengne AP. The prevalence of insufficient iodine intake in pregnancy in Africa: protocol for a systematic review and meta-analysis. Syst Rev 2019; 8:209. [PMID: 31439032 PMCID: PMC6706900 DOI: 10.1186/s13643-019-1092-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 07/02/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Insufficient iodine intake in pregnancy is associated with many adverse pregnancy outcomes. About 90% of African countries are at risk of iodine deficiency due to poor soils and dietary goitrogens. Pregnancy predisposes to insufficient iodine nutrition secondary to increased physiological demand and increased renal loss. Iodine deficiency is re-emerging in countries thought to be replete with pregnant women being the most affected. This review seeks to identify the degree of iodine nutrition in pregnancy on the entire African continent before and after the implementation of national iodization programmes. METHODS A systematic search of published literature will be conducted for observational studies that directly determined the prevalence of insufficient iodine intake among pregnant women in Africa. Electronic databases and grey literature will be searched for baseline data before the implementation of population-based iodine supplementation and for follow-up data up to December 2018. Screening of identified articles and data extraction will be conducted independently by two investigators. Risk of bias and methodological quality of the included studies will be assessed using a risk of bias tool. Appropriate meta-analytic techniques will be used to pool prevalence estimates from studies with similar features, overall and by major characteristics including the region of the study, time period (before and after implementation of iodization programmes), sample size and age. Heterogeneity of the estimates across studies will be quantified and publication bias investigated. This protocol is reported according to Preferred Reporting Items for Systematic reviews and Meta-Analysis protocols (PRISMA-P) 2015 guidelines. DISCUSSION This review will help ascertain the impact of national iodization programmes on the iodine nutrition status in pregnancy in Africa and advise policy on the necessity for monitoring and mitigating iodine deficiency in pregnancy in Africa. This review is part of a thesis that will be submitted to the Faculty of Health Sciences, University of Cape Town, for the award of a PhD in Medicine whose protocol has been granted ethics approval (UCT HREC 135/2018). In addition, the results will be published in a peer-reviewed journal. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42018099434.
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Affiliation(s)
- Charles Bitamazire Businge
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Department of Obstetrics and Gynaecology, Faculty of Health Sciences, Walter Sisulu University, Private Bag x1 WSU, 5117, Mthatha, South Africa
| | | | - Andre Pascal Kengne
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Non-Communicable Disease Research Unit, South African Medical Research Council, Cape Town, South Africa
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Dietary patterns and their effects on postpartum weight retention of lactating women in south central China. Nutrition 2019; 67-68:110555. [PMID: 31522086 DOI: 10.1016/j.nut.2019.110555] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/22/2019] [Accepted: 07/02/2019] [Indexed: 02/08/2023]
Abstract
OBJECTIVES Postpartum weight retention is a short- and long-term risk factor for overweight and obesity in women. The aim of this study was to evaluate dietary patterns and their effects on postpartum weight retention among lactating women in south central China. METHODS The study included 305 lactating women. A 24-h recall method on 3 consecutive d was used to collect dietary information. Furthermore, principal component analysis was performed to explore the main dietary patterns. The association between the postpartum weight retention and dietary patterns was assessed using a general linear regression model. RESULTS Two food patterns were obtained. Lactating women with dietary pattern 1 mainly ate red meat, coarse cereals, and fresh vegetables (leafy). Those with dietary pattern 2 mainly ate fresh vegetables (non-leafy), soy milk, and bacteria and algae. The mean energy, protein, fat, and carbohydrate intakes of the highest quartile (Q4) of both patterns exceeded the Chinese Recommended Nutrient Intake, whereas the calcium, selenium, vitamin A, B1, and C nutrient intakes in the highest quartile (Q4) of both patterns were lower than recommended. Dietary pattern 2 (B = -0.523, 95% confidence interval, -0.948 to -0.099) was negatively associated with postpartum weight retention. CONCLUSIONS This study identified two dietary patterns among lactating women in south central China. A diet characterized by high intake of fresh vegetables (non-leafy), soy milk, and bacteria and algae was negatively associated with postpartum weight retention.
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Donnay S, Fajardo C, Fernández-García JC, Torres T, Bandrés O, Domínguez JR, Menéndez E, Serrano J, Torrejón S, López I, Pineda JJ, Muñoz J, Lucas A, Tortosa F, Moll G, Vich F. Diagnosis, treatment, and management of gestational hypothyroidism. The TIROGEST study. ACTA ACUST UNITED AC 2019; 67:36-42. [PMID: 31109823 DOI: 10.1016/j.endinu.2019.03.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 02/03/2019] [Accepted: 03/08/2019] [Indexed: 10/26/2022]
Abstract
INTRODUCTION There is no agreement on the procedures to be used for diagnosis and treatment of gestational thyroid dysfunction. Controversy still exists on the normal range of thyroid-stimulating hormone (TSH) levels and use of gestational hypothyroidism (GH) screening. The aim of this study was to assess diagnosis and treatment of thyroid dysfunction during pregnancy in a group of Spanish hospitals. STUDY DESIGN This was a retrospective, multicenter study in pregnant females with GH attending Spanish healthcare centers from March 2013 to July 2014. Variables analyzed included diagnosis criteria for GH (availability of universal screening for gestational thyroid disorders and TSH reference values (RVs) by trimester of pregnancy): risk factors for GH, iodine intake from food or supplementation, gestational age (at diagnosis/treatment) and l-thyroxine treatment. RESULTS Fourteen centers participated in the study. Universal screening was performed in only half of the centers, and only 14% had their own TSH RVs. Overall, 257 pregnant women were enrolled, 53.7% with hypothyroidism (HT) diagnosed before pregnancy (pre-GH) and 46.3% with HT diagnosed during pregnancy (intra-GH). A comparison of intra-GH and pre-GH women showed that intra-GH women made their first visit later (59.7% vs. 75.4% respectively before week 12, p=0.007) and had more frequently high TSH levels (>2.5μIU/ml) during the first trimester (94.4% vs. 67.0% respectively, p<0.001). CONCLUSIONS Our results suggest that GH may be underdiagnosed or inadequately diagnosed in most healthcare centers. These findings suggest the need of improving the current practice in Spain.
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Affiliation(s)
- Sergio Donnay
- Hospital Universitario Fundación Alcorcón, Madrid, Spain.
| | - Carmen Fajardo
- Hospital Universitario de La Ribera, Alzira, Valencia, Spain
| | | | - Teresa Torres
- Centro de Atención Primaria Antoni Creus i Querol, Terrasa, Barcelona, Spain
| | | | | | | | | | - Sara Torrejón
- Hospital Moisès Broggi, Sant Joan Despí, Barcelona, Spain
| | - Irela López
- Hospital Moisès Broggi, Sant Joan Despí, Barcelona, Spain
| | | | - José Muñoz
- Centroe de Especialidades de Seo de Urgell, Spain
| | - Anna Lucas
- Hospital Universitari "Germans Trias i Pujol", Badalona, Barcelona, Spain
| | | | - Gracia Moll
- Hospital Comarcal de Inca, Inca, Mallorca, Spain
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Farebrother J, Zimmermann MB, Assey V, Castro MC, Cherkaoui M, Fingerhut R, Jia Q, Jukic T, Makokha A, San Luis TO, Wegmüller R, Andersson M. Thyroglobulin Is Markedly Elevated in 6- to 24-Month-Old Infants at Both Low and High Iodine Intakes and Suggests a Narrow Optimal Iodine Intake Range. Thyroid 2019; 29:268-277. [PMID: 30648484 DOI: 10.1089/thy.2018.0321] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND In areas with incomplete salt iodization coverage, infants and children aged 6-24 months weaning from breast milk and receiving complementary foods are at risk of iodine deficiency. However, few data exist on the risk of excessive iodine intake in this age group. Thyroglobulin (Tg) is a sensitive marker of iodine intake in school-age children and adults and may be used to estimate the optimal iodine intake range in infancy. The aim of this study was to assess the association of low and high iodine intakes with Tg and thyroid function in weaning infants. METHODS This multicenter cross-sectional study recruited infants aged 6-24 months (n = 1543; Mage = 12.2 ± 4.6 months) receiving breast milk with complementary foods, from seven countries in areas with previously documented deficient, sufficient, or excessive iodine intake in schoolchildren or pregnant women. Urinary iodine concentration (UIC) and Tg, total thyroxine, and thyrotropin were measured using dried blood spot testing. RESULTS Median UIC ranged from 48 μg/L (interquartile range 31-79 μg/L) to 552 μg/L (interquartile range 272-987 μg/L) across the study sites. Median Tg using dried blood spot testing was high (>50 μg/L) at estimated habitual iodine intakes <50 μg/day and >230 μg/day. Prevalence of overt thyroid disorders was low (<3%). Yet, subclinical hyperthyroidism was observed in the countries with the lowest iodine intake. CONCLUSIONS Tg is a sensitive biomarker of iodine intake in 6- to 24-month-old infants and follows a U-shaped relationship with iodine intake, suggesting a relatively narrow optimal intake range. Infants with low iodine intake may be at increased risk of subclinical thyroid dysfunction. In population monitoring of iodine deficiency or excess, assessment of iodine status using UIC and Tg may be valuable in this young age group.
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Affiliation(s)
- Jessica Farebrother
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
| | - Michael B Zimmermann
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
| | - Vincent Assey
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 3 Nutrition Services Section, Preventive Services Department; Ministry of Health, Community Development, Gender, Elderly, and Children, Dar es Salaam, Tanzania
| | | | - Mohamed Cherkaoui
- 5 Faculté des Sciences Semlalia, Université Caddi Ayyed, Marrakech, Morocco
| | - Ralph Fingerhut
- 6 Swiss Newborn Screening Laboratory and Children's Research Center; University Children's Hospital Zurich, Zurich, Switzerland
| | - Qingzhen Jia
- 7 Shanxi Institute for Prevention and Treatment of Endemic Disease, Linfen, P.R. China
| | - Tomislav Jukic
- 8 Department of Nuclear Medicine and Oncology, Sestre Milosrdnice University Hospital Center and School of Medicine, University of Zagreb, Zagreb, Croatia
- 9 Faculty of Medicine Osijek, University Josip Juraj Strossmayer Osijek, Osijek, Croatia
| | - Anselimo Makokha
- 10 Department of Food Science, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Theofilo O San Luis
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 11 St Luke's Medical Center, Quezon City, Manila, The Philippines
| | - Rita Wegmüller
- 12 Medical Research Council The Gambia, Keneba, The Gambia
| | - Maria Andersson
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 13 Division of Gastroenterology and Nutrition; University Children's Hospital Zurich, Zurich, Switzerland
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Delitala AP, Capobianco G, Cherchi PL, Dessole S, Delitala G. Thyroid function and thyroid disorders during pregnancy: a review and care pathway. Arch Gynecol Obstet 2018; 299:327-338. [PMID: 30569344 DOI: 10.1007/s00404-018-5018-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 12/12/2018] [Indexed: 12/28/2022]
Abstract
PURPOSE To review the literature on thyroid function and thyroid disorders during pregnancy. METHODS A detailed literature research on MEDLINE, Cochrane library, EMBASE, NLH, ClinicalTrials.gov, and Google Scholar databases was done up to January 2018 with restriction to English language about articles regarding thyroid diseases and pregnancy. RESULTS Thyroid hormone deficiencies are known to be detrimental for the development of the fetus. In particular, the function of the central nervous system might be impaired, causing low intelligence quotient, and mental retardation. Overt and subclinical dysfunctions of the thyroid disease should be treated appropriately in pregnancy, aiming to maintain euthyroidism. Thyroxine (T4) replacement therapy should reduce thyrotropin (TSH) concentration to the recently suggested fixed upper limits of 2.5 mU/l (first and second trimester) and 3.0 mU/l (third trimester). Overt hyperthyroidism during pregnancy is relatively uncommon but needs prompt treatment due to the increased risk of preterm delivery, congenital malformations, and fetal death. The use of antithyroid drug (methimazole, propylthiouracil, carbimazole) is the first choice for treating overt hyperthyroidism, although they are not free of side effects. Subclinical hyperthyroidism tends to be asymptomatic and no pharmacological treatment is usually needed. Gestational transient hyperthyroidism is a self-limited non-autoimmune form of hyperthyroidism with negative antibody against TSH receptors, that is related to hCG-induced thyroid hormone secretion. The vast majority of these patients does not require antithyroid therapy, although administration of low doses of β-blocker may by useful in very symptomatic patients. CONCLUSIONS Normal maternal thyroid function is essential in pregnancy to avoid adverse maternal and fetal outcomes.
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Affiliation(s)
- Alessandro P Delitala
- Azienda Ospedaliero-Universitaria Di Sassari, Clinica Medica, Viale San Pietro 8, 07100, Sassari, Italy.
| | - Giampiero Capobianco
- Department of Medical, Surgical and Experimental Sciences, University of Sassari, 07100, Sassari, Italy
| | - Pier Luigi Cherchi
- Department of Medical, Surgical and Experimental Sciences, University of Sassari, 07100, Sassari, Italy
| | - Salvatore Dessole
- Department of Medical, Surgical and Experimental Sciences, University of Sassari, 07100, Sassari, Italy
| | - Giuseppe Delitala
- Department of Medical, Surgical and Experimental Sciences, University of Sassari, 07100, Sassari, Italy
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Delshad H, Mirmiran P, Abdollahi Z, Salehi F, Azizi F. Continuously sustained elimination of iodine deficiency: a quarter of a century success in the Islamic Republic of Iran. J Endocrinol Invest 2018; 41:1089-1095. [PMID: 29446011 PMCID: PMC6132563 DOI: 10.1007/s40618-018-0838-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/22/2018] [Indexed: 11/02/2022]
Abstract
BACKGROUND Iodine deficiency and related disorders were very common in Iran prior to 1996, when universal salt iodization (USI) was implemented and in 2000 Iran was declared iodine deficiency disorders (IDD) free. The aim of this study was to evaluate the adequacy of iodine intake by Iranian households in all 30 provinces of Iran, a quarter of a century after the intervention. METHODS A total of 18,000 school-aged children (8-10 years with mean 8.7 ± 1 year) were included in this study. Urine samples were collected from all children for measurement of urinary iodine excretion and 1800, 210 and 3000 salt samples were randomly collected from the family kitchen, production site of 73 salt factories and distribution circles of 30 provinces, respectively. RESULTS The median urinary iodine concentration (UIC) of participants was 161 μg/L. The proportion of children with UIC of, 20-49, 50-99 and ≥ 100 μg/L were 10.3, 15.9 and 73.7%, respectively. The mean (± SD) and median salt iodine values were 28.2 (± 12.6) and 31.7 ppm, at the production site, and 31.5 (± 13.6) and 29.6 ppm at the distribution circles, respectively. About 80% of factory salts had more than 20 ppm iodine. 98% of households consumed iodized salt, 80% had appropriate salt storage, and 83% of the household salts contained ≥ 20 ppm. CONCLUSIONS Based on the results of this study, Iranian populations are consuming adequate iodine. The well-maintained and monitored USI program has improved the dietary iodine intakes of the population, and the country has achieved all criteria of a well-controlled IDD program.
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Affiliation(s)
- H. Delshad
- Micronutrient Research Office, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, 19395-4763 Tehran, Islamic Republic of Iran
| | - P. Mirmiran
- Nutrition Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran
| | - Z. Abdollahi
- Ministry of Health and Medical Education, Tehran, Islamic Republic of Iran
| | - F. Salehi
- Ministry of Health and Medical Education, Tehran, Islamic Republic of Iran
| | - F. Azizi
- Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran
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