22
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Iodine and thyroid function

      review-article
      , MD
      Annals of Pediatric Endocrinology & Metabolism
      The Korean Society of Pediatric Endocrinology
      Thyroid, Iodine, Hypothyroidism

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Severe iodine deficiency causes hypothyroidism that results in impaired somatic growth and motor development in children. Mild and moderate iodine deficiencies cause multifocal autonomous growth of thyroid, which results in thyrotoxicosis. On the other hand, iodine excess is associated with the development of hypothyroidism and thyroid autoimmunity. In areas of iodine deficiency, a sudden increase in iodine intake is associated with transient hyperthyroidism. Recent studies demonstrated that long-term thyroid function of subjects who experienced both iodine deficiency and iodine excess during childhood tended to be abnormal despite optimization of their current iodine intake. Iodine status in the Korean Peninsula is very unique because people in the Republic of Korea have been shown to have predominantly excessive iodine levels, whereas the Democratic People's Republic of Korea is known to be an iodine-deficient area. Further research is warranted to verify the optimal ranges of iodine intake and to clarify the effects of iodine intake on thyroid disorders in the Korean Peninsula.

          Related collections

          Most cited references48

          • Record: found
          • Abstract: found
          • Article: not found

          Iodine deficiency.

          Iodine deficiency has multiple adverse effects in humans, termed iodine deficiency disorders, due to inadequate thyroid hormone production. Globally, it is estimated that 2 billion individuals have an insufficient iodine intake, and South Asia and sub-Saharan Africa are particularly affected. However, about 50% of Europe remains mildly iodine deficient, and iodine intakes in other industrialized countries, including the United States and Australia, have fallen in recent years. Iodine deficiency during pregnancy and infancy may impair growth and neurodevelopment of the offspring and increase infant mortality. Deficiency during childhood reduces somatic growth and cognitive and motor function. Assessment methods include urinary iodine concentration, goiter, newborn TSH, and blood thyroglobulin. But assessment of iodine status in pregnancy is difficult, and it remains unclear whether iodine intakes are sufficient in this group, leading to calls for iodine supplementation during pregnancy in several industrialized countries. In most countries, the best strategy to control iodine deficiency in populations is carefully monitored universal salt iodization, one of the most cost-effective ways to contribute to economic and social development. Achieving optimal iodine intakes from iodized salt (in the range of 150-250 microg/d for adults) may minimize the amount of thyroid dysfunction in populations. Ensuring adequate iodine status during parenteral nutrition has become important, particularly in preterm infants, as the use of povidone-iodine disinfectants has declined. Introduction of iodized salt to regions of chronic iodine deficiency may transiently increase the incidence of thyroid disorders, but overall, the relatively small risks of iodine excess are far outweighed by the substantial risks of iodine deficiency.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Iodine-deficiency disorders.

            2 billion individuals worldwide have insufficient iodine intake, with those in south Asia and sub-Saharan Africa particularly affected. Iodine deficiency has many adverse effects on growth and development. These effects are due to inadequate production of thyroid hormone and are termed iodine-deficiency disorders. Iodine deficiency is the most common cause of preventable mental impairment worldwide. Assessment methods include urinary iodine concentration, goitre, newborn thyroid-stimulating hormone, and blood thyroglobulin. In nearly all countries, the best strategy to control iodine deficiency is iodisation of salt, which is one of the most cost-effective ways to contribute to economic and social development. When iodisation of salt is not possible, iodine supplements can be given to susceptible groups. Introduction of iodised salt to regions of chronic iodine-deficiency disorders might transiently increase the proportion of thyroid disorders, but overall the small risks of iodine excess are far outweighed by the substantial risks of iodine deficiency. International efforts to control iodine-deficiency disorders are slowing, and reaching the third of the worldwide population that remains deficient poses major challenges.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Assessment of iodine nutrition in populations: past, present, and future.

              Iodine status has been historically assessed by palpation of the thyroid and reported as goiter rates. Goiter is a functional biomarker that can be applied to both individuals and populations, but it is subjective. Iodine status is now assessed using an objective biomarker of exposure, i.e., urinary iodine concentrations (UICs) in spot samples and comparison of the median UIC to UIC cut-offs to categorize population status. This has improved standardization, but inappropriate use of the crude proportion of UICs below the cut-off level of 100 µg/L to estimate the number of iodine-deficient children has led to an overestimation of the prevalence of iodine deficiency. In this review, a new approach is proposed in which UIC data are extrapolated to iodine intakes, adjusted for intraindividual variation, and then interpreted using the estimated average requirement cut-point model. This may allow national programs to define the prevalence of iodine deficiency in the population and to quantify the necessary increase in iodine intakes to ensure sufficiency. In addition, thyroglobulin can be measured on dried blood spots to provide an additional sensitive functional biomarker of iodine status. © 2012 International Life Sciences Institute.
                Bookmark

                Author and article information

                Journal
                Ann Pediatr Endocrinol Metab
                Ann Pediatr Endocrinol Metab
                APEM
                Annals of Pediatric Endocrinology & Metabolism
                The Korean Society of Pediatric Endocrinology
                2287-1012
                2287-1292
                March 2014
                31 March 2014
                : 19
                : 1
                : 8-12
                Affiliations
                Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea.
                Author notes
                Address for correspondence: Hye Rim Chung, MD. Department of Pediatrics, Seoul National University Bundang Hospital, 82 Gumi-ro 173 beon-gil, Bundang-gu, Seongnam 463-707, Korea. Tel: +82-31-787-7292, Fax: +82-31-787-4054, chyerim@ 123456hanmail.net
                Article
                10.6065/apem.2014.19.1.8
                4049553
                24926457
                8ddf9e68-2de5-41ed-b2b3-b4f21110fc85
                © 2014 Annals of Pediatric Endocrinology & Metabolism

                This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                : 19 March 2014
                : 19 March 2014
                Categories
                Review Article

                thyroid,iodine,hypothyroidism
                thyroid, iodine, hypothyroidism

                Comments

                Comment on this article