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Abstract
Iodine is a micronutrient needed for the production of thyroid hormones, which regulate metabolism, growth, and development. Iodine deficiency or excess may alter the thyroid hormone synthesis. The potential effects on infant development depend on the degree, timing, and duration of exposure. The iodine requirement is particularly high during infancy because of elevated thyroid hormone turnover. Breastfed infants rely on iodine provided by human milk, but the iodine concentration in breast milk is determined by the maternal iodine intake. Diets in many countries cannot provide sufficient iodine, and deficiency is prevented by iodine fortification of salt. However, the coverage of iodized salt varies between countries. Epidemiological data suggest large differences in the iodine intake in lactating women, infants, and toddlers worldwide, ranging from deficient to excessive intake. In this review, we provide an overview of the current knowledge and recent advances in the understanding of iodine nutrition and its association with thyroid function in lactating women, infants, and toddlers. We discuss risk factors for iodine malnutrition and the impact of targeted intervention strategies on these vulnerable population groups. We highlight the importance of appropriate definitions of optimal iodine nutrition and the need for more data assessing the risk of mild iodine deficiency for thyroid disorders during the first 2 years in life.
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Affiliation(s)
- Maria Andersson
- Nutrition Research Unit, University Children’s Hospital Zurich, CH-8032 Zürich, Switzerland
| | - Christian P Braegger
- Nutrition Research Unit, University Children’s Hospital Zurich, CH-8032 Zürich, Switzerland
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Nazeri P, Tahmasebinejad Z, Pearce EN, Zarezadeh Z, Tajeddini T, Mirmiran P, Azizi F. Does maternal iodine supplementation during the lactation have a positive impact on neurodevelopment of children? Three-year follow up of a randomized controlled trial. Eur J Nutr 2021; 60:4083-4091. [PMID: 33974129 DOI: 10.1007/s00394-021-02574-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/27/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE The aim of this study was to examine, for the first time, the neurodevelopmental outcomes in children whose mothers received different doses of iodine supplements during lactation. METHODS We conducted a follow-up study on children whose mothers participated in a randomized clinical trial to receive placebo, 150 µg/day or 300 µg/day of iodine until 12 months postpartum. Child neurocognitive development was assessed at 36 months of age using the Bayley Scales of Infant and Toddler Development Third Edition. Linear mixed-model analysis was preformed to assess iodine supplement dose effects on child cognitive, language, and motor functions. RESULTS A total of 122 children provided neurodevelopmental data as follows: 300 µg/d iodine group: 45; 150 µg/d iodine group: 35; and placebo group: 42. Cognitive scores were higher in children whose mothers received 150 µg iodine/d compared to children whose mothers received placebo [102.8 (SD 13.2) vs. 99.2 (SD 10.5); β = 4.43, P = 0.032]. However, supplementation with 150 µg iodine/d had no effect on language or motor development. No significant differences were observed in cognitive, language, or motor functions between children whose mothers received 300 µg iodine/d and those whose mothers received 150 µg iodine/d or placebo. CONCLUSION Maternal iodine supplementation with 150 µg/d during lactation may have a beneficial effect on child cognitive development; however, we found no evidence of either improved or delayed neurodevelopmental outcomes in children whose mothers received iodine supplements at doses higher than recommended. Further randomized controlled trials with larger sample sizes are needed to confirm these results. CLINICAL TRIAL REGISTRY IRCT201303164794N8; registration date: 2013-05-20.
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Affiliation(s)
- Pantea Nazeri
- Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Zhale Tahmasebinejad
- Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box: 19395-4763, Tehran, Iran
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, USA
| | - Zinat Zarezadeh
- Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Tahere Tajeddini
- Family Health Institute, Breastfeeding Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Parvin Mirmiran
- Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box: 19395-4763, Tehran, Iran. .,Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, P.O. Box: 19395-4763, Tehran, Iran.
| | - Fereidoun Azizi
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box: 19395-4763, Tehran, Iran.
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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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Ellsworth L, McCaffery H, Harman E, Abbott J, Gregg B. Breast Milk Iodine Concentration Is Associated with Infant Growth, Independent of Maternal Weight. Nutrients 2020; 12:E358. [PMID: 32019065 PMCID: PMC7071233 DOI: 10.3390/nu12020358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/26/2020] [Accepted: 01/27/2020] [Indexed: 12/22/2022] Open
Abstract
In breastfed infants, human milk provides the primary source of iodine to meet demands during this vulnerable period of growth and development. Iodine is a key micronutrient that plays an essential role in hormone synthesis. Despite the importance of iodine, there is limited understanding of the maternal factors that influence milk iodine content and how milk iodine intake during infancy is related to postnatal growth. We examined breast milk samples from near 2 weeks and 2 months post-partum in a mother-infant dyad cohort of mothers with pre-pregnancy weight status defined by body mass index (BMI). Normal (NW, BMI < 25.0 kg/m2) is compared to overweight/obesity (OW/OB, BMI ≥ 25.0 kg/m2). The milk iodine concentration was determined by inductively coupled plasma mass spectrometry. We evaluated the associations between iodine content at 2 weeks and infant anthropometrics over the first year of life using multivariable linear mixed modeling. Iodine concentrations generally decreased from 2 weeks to 2 months. We observed no significant difference in iodine based on maternal weight. A higher iodine concentration at 2 weeks was associated with a larger increase in infant weight-for-age and weight-for-length Z-score change per month from 2 weeks to 1 year. This pilot study shows that early iodine intake may influence infant growth trajectory independent of maternal pre-pregnancy weight status.
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Affiliation(s)
- Lindsay Ellsworth
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Harlan McCaffery
- Center for Human Growth and Development, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Emma Harman
- School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Jillian Abbott
- Metals Laboratory, Division of Clinical Biochemistry and Immunology, Mayo Clinic, Rochester, MN 55905, USA;
| | - Brigid Gregg
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
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Croce L, Di Dalmazi G, Orsolini F, Virili C, Brigante G, Gianetti E, Moleti M, Napolitano G, Tonacchera M, Rotondi M. Graves' Disease and the Post-partum Period: An Intriguing Relationship. Front Endocrinol (Lausanne) 2019; 10:853. [PMID: 31920967 PMCID: PMC6914725 DOI: 10.3389/fendo.2019.00853] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/21/2019] [Indexed: 11/29/2022] Open
Abstract
The post-partum period is an immunologically peculiar period in a woman's life. Indeed, most of the pregnancy-related immune changes gradually revert in the 12 months following delivery. Although the post-partum period has long been identified as a period of aggravation of autoimmune thyroid diseases, most of the currently available studies took into account the relationship between post-partum and autoimmune thyroiditis. More recently, the potential repercussions of the post-partum period on Graves' disease were also taken into account. The present mini review will briefly overview the most recent advances in our knowledge of the immunology of the post-partum period in relation with the potential repercussions on the clinical course of Graves' disease. Moreover, some peculiar aspects of post-partum Graves' disease in terms of clinical and biochemical presentation, diagnostic challenges, and specific therapeutic considerations also taking into account the recommendation of the latest clinical guidelines on the management of thyroid diseases in pregnancy will be overviewed.
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Affiliation(s)
- Laura Croce
- Unit of Internal Medicine and Endocrinology, Laboratory for Endocrine Disruptors, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
- PHD course in Experimental Medicine, University of Pavia, Pavia, Italy
| | - Giulia Di Dalmazi
- Unit of Endocrinology, Department of Medicine and Sciences of Aging, “G. D'Annunzio” University of Chieti-Pescara, Chieti, Italy
| | - Francesca Orsolini
- Endocrinology Section, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Camilla Virili
- Endocrinology Unit, Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - Giulia Brigante
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Elena Gianetti
- Endocrinology Section, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Mariacarla Moleti
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Giorgio Napolitano
- Unit of Endocrinology, Department of Medicine and Sciences of Aging, “G. D'Annunzio” University of Chieti-Pescara, Chieti, Italy
| | - Massimo Tonacchera
- Endocrinology Section, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Mario Rotondi
- Unit of Internal Medicine and Endocrinology, Laboratory for Endocrine Disruptors, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
- *Correspondence: Mario Rotondi
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