Thyroid Diseases: Delange F

Anonymous00393, Andersson M, de Benoist B, Delange F, Zupan J. · Department of Nutrition for Health and Development, World Health Organization, 8803 Rüschlikon, ZH, Switzerland. · Public Health Nutr. · Pubmed #18053287 No free full text.

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Delange F. · Department of Pediatrics, University of Brussels, Brussels, Belgium. · J Pediatr Endocrinol Metab. · Pubmed #16398455 No free full text.

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Delange F. · International Council for Control of Iodine Deficiency Disorders, Brussels, Belgium. · Forum Nutr. · Pubmed #15806798 No free full text.

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Zimmermann M, Delange F. · Laboratory for Human Nutrition, Institute of Food Science and Nutrition, Swiss Federal Institute of Technology, Rüschlikon, Zürich, Switzerland. · Eur J Clin Nutr. · Pubmed #15220938 No free full text.

Abstract: OBJECTIVE: Nearly two-thirds of the population of Western and Central Europe live in countries that are iodine deficient. Damage to reproductive function and to the development of the fetus and newborn is the most important consequence of iodine deficiency. The objective of this review was to examine the iodine status of pregnant women in Europe and the potential need for iodine supplementation. DESIGN: A MEDLINE/PubMed search and compilation of all published studies since 1990 of iodine nutrition and iodine supplementation of pregnant women in Europe, as well as an Internet-based search and review on availability and legislation of iodine supplements in the European Union. RESULTS: Although the data suggest most women in Europe are iodine deficient during pregnancy, less than 50% receive supplementation with iodine. Mild-to-moderate iodine deficiency during pregnancy adversely affects thyroid function of the mother and newborn and mental development of the offspring and these adverse effects can be prevented or minimized by supplementation. There are no published data on the effect of iodine supplementation on long-term maternal and child outcomes. The iodine content of prenatal supplements in Europe varies widely; many commonly used products contain no iodine. The European Union is developing legislation to establish permissible levels for iodine in food supplements. CONCLUSIONS: In most European countries, pregnant women and women planning a pregnancy should receive an iodine-containing supplement ( approximately 150 microg/day). Kelp and seaweed-based products, because of unacceptable variability in their iodine content, should be avoided. Prenatal supplement manufacturers should be encouraged to include adequate iodine in their products. Professional organizations should influence evolving EU legislation to ensure optimal doses for iodine in prenatal vitamin-mineral supplements. SPONSORSHIP: International Council for Control of Iodine Deficiency Disorders.

Delange F, Bürgi H, Chen ZP, Dunn JT. · International Council for Control of Iodine Deficiency Disorders, Brussels, Belgium. · Thyroid. · Pubmed #12494927 No free full text.

Abstract: Monitoring and evaluation are the last phases of a national iodine deficiency disorders (IDD) control program but among the most important. This paper summarizes the latest recommendations by the World Health Organization (WHO), the United Nations Children's Fund (UNICEF), and the International Council for Control of Iodine Deficiency Disorders (ICCIDD) about indicators and their normative values for monitoring the progress of IDD elimination and illustrates the successful monitoring programs in Switzerland and in China. Salt is the usual vehicle for iodine supplementation and quality control for iodine content can be assessed quantitatively by titration and qualitatively by simple test kits that can be used in the field. The most useful indicator of iodine nutrition is the median urinary iodine concentration. Thyroid size, especially by ultrasound, and neonatal thyrotropin (TSH) are also valuable. In Switzerland, access to iodized salt on a voluntary basis started in 1922. The initial level of iodization, 1.9-3.75 ppm iodine as potassium iodide (KI), was slowly increased to 15 ppm, and recently to 20 ppm, after careful epidemiologic and biologic monitoring. Elimination of IDD has been highly successful. The program costs US dollars 0.07 per year per person. In China, a national program of iodized salt (10-30 ppm) started in 1960 under the authority of the central government and rapidly expanded. National monitoring surveys have taken place every 2 years since 1993. Median urinary iodine, initially low, increased to 165 microg/L in 1995 and to 306 microg/L in 1999, prompting a decrease in the amount of iodine added to salt. The total goiter rate decreased to 20.4% in 1995 and to 8.8% in 1999. IDD can presently be considered as eliminated in China. Review of monitoring in the 128 other major countries affected by IDD shows extremely variable achievements, with evidence of IDD elimination in at least 18 additional countries. Some countries that were severely iodine deficient in the past are now exposed to iodine excess and risk its effects. Sustainable elimination of IDD is within reach and would constitute an unprecedented global success story in the field of noncommunicable diseases, but continuing vigorous action is required to attain this goal.

Delange F. · International Council for Control of Iodine Deficiency Disorders, Department of Pediatrics, Hospital Saint-Pierre, University of Brussels, 153, avenue de la Fauconnerie, 1170 Brussels, Belgium. · Eur J Nucl Med Mol Imaging. · Pubmed #12192540 No free full text.

Abstract: This paper updates the information on the prevalence of the disorders induced by iodine deficiency (IDD) in Europe. Thirty-two European countries were still affected by mild to severe iodine deficiency in the late 1990s. The most severely affected countries were in Eastern Europe, including Central Asia, but Western Europe was also still affected. National surveys recently conducted in 11 of these countries show that, with the exception of the Netherlands, none has yet reached a state of iodine sufficiency, though very significant improvement in the situation has been evidenced in many of them, e.g. Poland, Bulgaria and Macedonia. The consequences of persisting iodine deficiency are goitre, hyperavidity of the thyroid for iodide (which increases the risk of thyroid irradiation in the event of a nuclear accident) and subclinical hypothyroidism during pregnancy and early infant (with a concomitant risk of minor brain damage and irreversible impairment of the neuropsychointellectual development of offspring). Access to iodised salt at the household level in European countries affected by IDD increased from 5%-10% in 1990 to 28% in 1999. This constitutes encouraging progress. However, in terms of access of iodine-deficient countries to iodised salt, Europe remains the worst region in the world, as shown by the fact that the mean figure worldwide in 1999 was 68%. In Latin America it even reached 90%. Salt iodisation has to be further implemented in Europe. Until that goal is achieved, iodine supplementation in those groups most sensitive to the effects of iodine deficiency (pregnant and lactating women and young infants) will have to be considered in the most severely affected areas.

De Benoist B, Delange F. · Département de nutrition pour la santé et le développement, Organisation mondiale de la santé, CH 1211 Genève 27, Suisse. · Sante. · Pubmed #11943633 links to  free full text

Abstract: Iodine deficiency disorders (IDD) is a major public health problem worldwide. WHO estimates that 740 million people are currently affected by goitre. The consequences of iodine deficiency on health are the results of hypothyroidism and the main one is impaired development of foetal brain. IDD is the first cause of preventable brain damage in children. The recommended strategy to correct IDD rests upon salt iodisation. Over the last 20 years, the international community mobilised to eliminate IDD under the leadership of WHO, Unicef and ICCIDD. It resulted in remarkable progress in IDD control, especially in Africa and in South East Asia where the endemic is the most severe. It is estimated that 68% of the populations of affected countries have currently access to iodised salt. However, out of the 130 affected countries, about 30 have no programme. Besides, salt quality control and monitoring of population iodine status are still weak in many countries, thus exposing the population to an excessive iodine intake and subsequently to the risk of iodine-induced hyperthyroidism. In addition, IDD is re-emerging in some countries, especially in Eastern Europe after it had disappeared. In order to reach the goal of IDD elimination, it is important to insist on the sustainability of salt iodisation programmes, which implies an increased commitment of both health authorities and representatives of the salt industry.

Delange F, de Benoist B, Pretell E, Dunn JT. · International Council for Control of Iodine Deficiency Disorders, Brussels, Belgium. · Thyroid. · Pubmed #11396702 No free full text.

Abstract: Iodine deficiency is the leading cause of preventable mental retardation. Universal salt iodization (USI), calling for all salt used in agriculture, food processing, catering and household to be iodized, is the agreed strategy for achieving iodine sufficiency. This article reviews published information on programs for the sustainable elimination of the iodine deficiency disorders and reports new data on monitoring and impact of salt iodization programs at the population level. Currently, 68% of households from areas of the world with previous iodine deficiency have access to iodized salt, compared to less than 10% a decade ago. This great achievement, a public health success unprecedented in the field of noncommunicable diseases, must be better recognized by the health sector, including thyroidologists. On the other hand, the managers and sponsors of programs of iodized salt must appreciate the continuing need for greatly improved monitoring and quality control. For example, partnership evaluation of iodine nutrition using the ThyroMobil model in 35,223 schoolchildren at 378 sites of 28 countries has shown that many previously iodine deficient parts of the world now have median urinary iodine concentrations well above 300 microg/L, which is excessive and carries the risk of adverse health consequences. The elimination of iodine deficiency is within reach but major additional efforts are required to cover the whole population at risk and to ensure quality control and sustainability.

Glinoer D, Delange F. · University Hospital Saint-Pierre, Department of Internal Medicine-Thyroid Investigation Clinic, Brussels, Belgium. · Thyroid. · Pubmed #11081254 No free full text.

Abstract: The adequate functioning of both the maternal and fetal thyroid glands play an important role to ensure that the fetal neuropsycho-intellectual development progresses normally. Three sets of clinical disorders are considered, that may eventually lead to impaired brain development. Firstly, in infants with a defect of glandular ontogenesis (congenital hypothyroidism), the participation of maternal thyroid hormones to the fetal circulating thyroxine environment is normal and, therefore, risk of brain damage results exclusively from the insufficient hormone production by the abnormal fetal thyroid gland. Secondly, when it is only the maternal thyroid gland that is functionally deficient (autoimmune hypothyroidism), the severity and temporal occurrence of maternal underfunction will both drive the resulting consequences for impaired fetal neuronal development. Clinical situations of this type may obviously take place already during early gestation (in women with known but untreated hypothyroidism) or appear only during later gestational stages (in women who have AITD and remain euthyroid during the first half of gestation). Lastly, in conditions with iodine deficiency, both maternal and fetal thyroid functions are affected and, therefore, it is primarily the degree and precocity of the maternal hypothyroxinemia due to iodine deficiency during pregnancy that will drive the potential repercussions for fetal neurological development. In the present review, we summarize available data and develop our present concepts concerning the complex feto-maternal thyroid relationships and the potential impacts of thyroid function abnormalities on the ideal development of the offspring.

Delange F. · International Council for Control of Iodine Deficiency Disorders, 153 Avenue de la Fauconnerie, B-1170 Brussels, Belgium. · Proc Nutr Soc. · Pubmed #10828176 No free full text.

Abstract: I is required for the synthesis of thyroid hormones. These hormones, in turn, are required for brain development, which occurs during fetal and early postnatal life. The present paper reviews the impact of I deficiency (1) on thyroid function during pregnancy and in the neonate, and (2) on the intellectual development of infants and children. All extents of I deficiency (based on I intake (microgram/d); mild 50-99, moderate 20-49, severe > 20) affect the thyroid function of the mother and neonate, and the mental development of the child. The damage increases with the extent of the deficiency, with overt endemic cretinism as the severest consequence. This syndrome combines irreversible mental retardation, neurological damage and thyroid failure. Maternal hypothyroxinaemia during early pregnancy is a key factor in the development of the neurological damage in the cretin. Se deficiency superimposed on I deficiency partly prevents the neurological damage, but precipitates severe hypothyroidism in cretins. I deficiency results in a global loss of 10-15 intellectual quotient points at a population level, and constitutes the world's greatest single cause of preventable brain damage and mental retardation.

Delange F, Lecomte P. · International Council for Control of Iodine Deficiency Disorders, Brussels, Belgium. · Drug Saf. · Pubmed #10672891 No free full text.

Abstract: In 1990, iodine deficiency affected almost one-third of the world population and was the greatest single cause of preventable brain damage and mental retardation. Following a resolution adopted by the World Summit for Children in 1990. major programmes of iodine supplementation were implemented by the governments of the affected countries with the support of major donors. Iodisation of salt was recognised as the method of choice. Nine years later, by April 1999, 75% of the affected countries had legislation on salt iodisation and 68% of the affected populations had access to iodised salt. The prevalence of iodine deficiency disorders decreased drastically in most countries and the deficiency disappeared completely in some such as Peru. This result constitutes a public heath success unprecedented with a non-infectious disease. However, occasional adverse effects occurred. The principle effect is iodine-induced hyperthyroidism which occurs essentially in older people with autonomous nodular goitres, especially following iodine intake that is too rapid and of too massive an increment. The incidence of the disorder is usually low and reverts spontaneously to the background rate of hyperthyroidism or even below this rate after 1 to 10 years of iodine supplementation. The possible occurrence of iodine-induced thyroiditis in susceptible individuals has not been clearly demonstrated by large epidemiological surveys. Iodine supplementation is followed by an increased prevalence of occult papillary carcinoma of the thyroid discovered at autopsy but the prognosis of thyroid cancer is improved due to a shift towards differentiated forms of thyroid cancer that are diagnosed at earlier stages. Iodine-induced hyperthyroidism and other adverse effects can be almost entirely avoided by adequate and sustained quality control and monitoring of iodine supplementation which should also confirm adequate iodine intake. Available evidence clearly confirms that the benefits of correcting iodine deficiency far outweigh the risks of iodine supplementation.

Simescu M, Varciu M, Nicolaescu E, Gnat D, Podoba J, Mihaescu M, Delange F. · Institute of Endocrinology, Bucharest, Romania. · Horm Res. · Pubmed #12207166 No free full text.

Abstract: OBJECTIVE: To evaluate the long-term efficacy and possible side effects of low doses of iodized oil on iodine nutrition and thyroid function in endemic goiter in Romania. METHODS: Random selection of 214 schoolchildren aged 6-14 years. Serial measurements of urinary iodine, thyroid volume with ultrasound, serum concentrations of thyrotropin, free thyroxine, thyroglobulin and thyroid autoantibodies before and up to 2 years after the oral administration of 200 mg iodine in iodized oil. RESULTS: Urinary iodine concentrations indicated a moderate iodine deficiency before therapy, sharply increased soon after therapy and slowly decreased thereafter but remained within the normal range up to more than 1 year after therapy. The prevalence of goiter was 29% before the administration of iodized oil and 9% 1 year later. Thyroid function tests and autoantibodies were normal before and up to 2 years after therapy. CONCLUSION: A single dose of 200 mg iodine from oral Lipiodol appears adequate and safe for correcting moderate iodine deficiency in children.

Anonymous00110, Becker DV, Braverman LE, Delange F, Dunn JT, Franklyn JA, Hollowell JG, Lamm SH, Mitchell ML, Pearce E, Robbins J, Rovet JF. · No affiliation provided · Thyroid. · Pubmed #17042677 No free full text.

Abstract: The fetus is totally dependent in early pregnancy on maternal thyroxine for normal brain development. Adequate maternal dietary intake of iodine during pregnancy is essential for maternal thyroxine production and later for thyroid function in the fetus. If iodine insufficiency leads to inadequate production of thyroid hormones and hypothyroidism during pregnancy, then irreversible fetal brain damage can result. In the United States, the median urinary iodine (UI) was 168 microg/L in 2001-2002, well within the range of normal established by the World Health Organization (WHO), but whereas the UI of pregnant women (173 microg/L; 95% CI 75-229 microg/L) was within the range recommended by WHO (150-249 microg/L), the lower 95% CI was less than 150 microg/L. Therefore, until additional physiologic data are available to make a better judgment, the American Thyroid Association recommends that women receive 150 microg iodine supplements daily during pregnancy and lactation and that all prenatal vitamin/mineral preparations contain 150 microg of iodine.

Pretell EA, Delange F, Hostalek U, Corigliano S, Barreda L, Higa AM, Altschuler N, Barragán D, Cevallos JL, Gonzales O, Jara JA, Medeiros-Neto G, Montes JA, Muzzo S, Pacheco VM, Cordero L. · International Council for the Control of Iodine Deficiency Disorders, Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Lima, Perú. · Thyroid. · Pubmed #15320971 No free full text.

Abstract: Iodine deficiency has been a public health problem in most Latin American countries. Massive programs of salt iodization have achieved great progress toward its elimination but no consistent monitoring has been applied. We used the ThyroMobil model to visit 163 sites in 13 countries and assess randomly selected schoolchildren of both genders 6-12 years of age. The median urinary iodine concentration (8208 samples) varied from 72 to 540 microg/L. One national median was below the recommended range of 100-200 microg/L; five were 100-200 microg/L, and seven were higher than 200 microg/L, including three greter than 300 microg/L. Urinary iodine concentration correlated with the iodine content of salt in all countries. Median values of thyroid volume were within the normal range for age in all countries, but the goiter prevalence varied markedly from 3.1% to 25.0% because of scatter. The median iodine content of salt from local markets (2734 samples) varied from 5.9 parts per million (ppm) to 78 ppm and was greater than 15 ppm in 83.1% of all samples. Only seven countries had higher than 15 ppm iodine in 80% of the samples, and only three had greater than 15 ppm in at least 90%. Iodized salt was available at retail level in all countries but its median iodine content was within the recommended range (20-40 ppm) in only five. This study, the first to apply a standardized assessment strategy to recent iodine nutrition in Latin America, documents a remarkable success in the elimination of iodine deficiency by iodized salt in all but 1 of the 13 countries. Some iodine excess occurs, but side effects have not been reported so far, and two countries have already decreased their legal levels of salt iodization and improved the quality control of iodized salt, in part because of our results. The present work should be followed by regular monitoring of iodine nutrition and thyroid function, especially in the countries presently exposed to iodine excess.

Zamrazil V, Bilek R, Cerovska J, Delange F. · Institute of Endocrinology, Prague, Czech Republic. · Thyroid. · Pubmed #15009914 No free full text.

Abstract: The Czech Republic has a long history of iodine deficiency. Salt iodization was introduced in 1947, followed by a progressive correction of iodine deficiency. The present study reports the changes in the status of iodine nutrition and of thyroid function in the country from 1994 to 2002. The study included 29612 individuals, aged 0 to 98 years, including 5263 individuals randomly selected from the general population and 24349 individuals who attended the Institute of Endocrinology of Prague (hospital population). Urinary iodine was determined in all individuals. Measurements of serum thyrotropin (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and thyroglobulin (Tg), were taken in 8544 to 19060 individuals. The iodine content of table salt was measured in 1130 samples. The median urinary iodine in the general and hospital populations were not significantly different. They progressively increased with time, starting from values indicating mild iodine deficiency (88-95 microg/L) prior to 1997, reaching the critical threshold of 100 microg/L in 1998, and optimal values between 120-140 microg/L since 2000. There was only a low and not significant positive correlation between the iodine content of salt and the urinary iodine. In contrast, urinary iodine showed marked seasonal changes, with the highest values during winter, when livestock were supplemented by mineral tablets containing iodine. Variables exploring thyroid function were all situated within the normal range in adults but another study (results not reported) has shown the persistence of slightly elevated TSH in neonates. The correction of iodine deficiency was not accompanied by unfavorable side effects. In conclusion, the Czech Republic has achieved sustainable elimination of iodine deficiency. Salt iodization has been a determining, but not the only, factor responsible for the success. Iodine supplementation of livestock and increased consumption of milk rich in iodine have probably played a determining role. Neonatal thyroid screening could constitute the major monitoring tool in order to insure sustainable elimination of iodine deficiency in the Czech Republic.

Zimmermann MB, Hess SY, Molinari L, De Benoist B, Delange F, Braverman LE, Fujieda K, Ito Y, Jooste PL, Moosa K, Pearce EN, Pretell EA, Shishiba Y. · Laboratory for Human Nutrition, Swiss Federal Institute of Technology Zürich, Rüschlikon, Switzerland. · Am J Clin Nutr. · Pubmed #14749228 links to  free full text

Abstract: BACKGROUND: Goiter prevalence in school-age children is an indicator of the severity of iodine deficiency disorders (IDDs) in a population. In areas of mild-to-moderate IDDs, measurement of thyroid volume (Tvol) by ultrasound is preferable to palpation for grading goiter, but interpretation requires reference criteria from iodine-sufficient children. OBJECTIVE: The study aim was to establish international reference values for Tvol by ultrasound in 6-12-y-old children that could be used to define goiter in the context of IDD monitoring. DESIGN: Tvol was measured by ultrasound in 6-12-y-old children living in areas of long-term iodine sufficiency in North and South America, central Europe, the eastern Mediterranean, Africa, and the western Pacific. Measurements were made by 2 experienced examiners using validated techniques. Data were log transformed, used to calculate percentiles on the basis of the Gaussian distribution, and then transformed back to the linear scale. Age- and body surface area (BSA)-specific 97th percentiles for Tvol were calculated for boys and girls. RESULTS: The sample included 3529 children evenly divided between boys and girls at each year ( +/- SD age: 9.3 +/- 1.9 y). The range of median urinary iodine concentrations for the 6 study sites was 118-288 micro g/L. There were significant differences in age- and BSA-adjusted mean Tvols between sites, which suggests that population-specific references in countries with long-standing iodine sufficiency may be more accurate than is a single international reference. However, overall differences in age- and BSA-adjusted Tvols between sites were modest relative to the population and measurement variability, which supports the use of a single, site-independent set of references. CONCLUSION: These new international reference values for Tvol by ultrasound can be used for goiter screening in the context of IDD monitoring.

Erdoğan G, Erdoğan MF, Delange F, Sav H, Güllü S, Kamel N. · Department of Endocrinology and Metabolism, University of Ankara School of Medicine, Sihhiye, Turkey. · Eur J Epidemiol. · Pubmed #11484802 No free full text.

Abstract: Endemic goitre is still an important and underestimated health concern in Turkey. The overall prevalence had been calculated as 30.3% by palpation in a national survey conducted in 1995. However, direct evidence that iodine deficiency (ID) is the major cause of the endemic were lacking until now. We measured sonographic thyroid volumes (STV), urinary iodine concentrations (UIC) in 1226 school age children (SAC) (9-11 year old) from Ankara the capital of Turkey located in the central Anatolia, and three highly endemic goitre areas of the Black Sea region. A considerable number of school age children (SAC) were found to have STV exceeding the recommended upper normal limits for their age and gender obtained from iodine-replete European children (i.e. 26.7, 40.3, 44.8 and 51.7% of children from Ankara, Kastamonu, Bayburt and Trabzon respectively). UIC indicated moderate to severe ID in these areas with median concentrations of 25.5, 30.5, 16.0 and 14 microg/L respectively. This study showed severe to moderate ID as the primary etiological factor for the goitre endemic observed in Ankara and the Black Sea region of Turkey.

Delange F. · International Council For Control of Iodine Deficiency Disorders, Brussels, Belgique. · Cell Mol Biol (Noisy-le-grand). · Pubmed #11441947 No free full text.

Abstract: The Professor F. Delange has a substantial experience, since the last decade, in implementing universal salt iodization in a lot of countries, and assessing its impact on iodine deficiency disorders. He comments here the published results of D.E. Hindié et al. concerning the side effects of stable iodine overload on thyroid structure in the young rat (N. Colas-Linhart).

Delange F, Wolff P, Gnat D, Dramaix M, Pilchen M, Vertongen F. · International Council for Control of Iodine Deficiency Disorders (ICCIDD), 153 Avenue de la Fauconnerie, 1170-Brussels, Belgium. · Eur J Pediatr. · Pubmed #11317650 No free full text.

Abstract: Iodine deficiency is well documented in Belgium in adults including pregnant women, adolescents, schoolchildren, and neonates, but no data are available in the age group 6 months-3 years. We investigated the status of iodine nutrition in 111 healthy subjects in this age group in an attempt to evaluate the risk of brain damage due to iodine deficiency in Belgium. In 244 causal urine samples collected in these subjects, the median concentration of iodine was 101 micrograms/l vs 180-220 micrograms/l under normal conditions. The daily supplementation of the subjects with a physiological dose of 90 micrograms iodine was followed by a slow and progressive increase of urinary iodine, which reached a normal level only after a delay of about 30 weeks of therapy. This observation suggests that part of the supplement of iodine offered to the children was stored in their thyroid glands until the iodine content of the gland had reverted to normal, reflecting the state of hyperavidity of the thyroid for iodide characteristic of iodine deficiency. In conclusion, infants and young children in Belgium are as iodine deficient as all other age groups of the population and, consequently, are at risk of brain damage. This works further illustrates the need for systematic iodine supplementation of the population in Belgium.

Szybinski Z, Delange F, Lewinski A, Podoba J, Rybakowa M, Wasik R, Szewczyk L, Huszno B, Gołkowski F, Przybylik-Mazurek E, Karbownik M, Zak T, Pantoflinski J, Trofimiuk M, Kinalska I. · Department of Endocrinology, Medical College, Jagiellonian University in Krakow, Poland. · Eur J Endocrinol. · Pubmed #11275941 links to  free full text

Abstract: BACKGROUND: Iodine prophylaxis in Poland started in 1935 and has been interrupted twice: by World War II and in 1980 for economic reasons. Epidemiological surveys carried out after the Chernobyl accident in 1989 as well as in 1992/1993 and in 1994 as a 'ThyroMobil' study, revealed increased prevalence of goitre in children and adults. Ninety per cent of Poland was classified as an area of moderate iodine deficiency, and 10%, in the seaside area, as mild iodine deficiency territory. Iodine prophylaxis based on iodisation of household salt was introduced again in 1986 as a voluntary model and in 1997 as a mandatory model with 30+/-10 mg KI/kg salt. OBJECTIVE: The evaluation of the obligatory model of iodine prophylaxis in schoolchildren from the same schools in 1994 and 1999. METHODS: Thyroid volume was determined by ultrasonography. Ioduria in casual morning urine samples was measured using Sandell-Kolthoff's method, within the framework of the ThyroMobil study. RESULTS: Goitre prevalence decreased from 38.4 to 7% and urinary iodine concentration increased from 60.4 to 96.2 microg/l mean values between 1994 and 1999. In four schools the prevalence of goitre diminished below 5%. In 1999, 70% of children excreted over 60 microg I/l, and 36% over 100 microg I/l, whereas in 1994 the values were 44 and 13% respectively. CONCLUSION: The present findings indicate that iodine prophylaxis based only on iodised household salt is highly effective.

Zimmermann MB, Molinari L, Spehl M, Weidinger-Toth J, Podoba J, Hess S, Delange F. · The Laboratory for Human Nutrition, Swiss Federal Institute of Technology, Zurich, Switzerland. · Eur J Endocrinol. · Pubmed #11248739 links to  free full text

Abstract: OBJECTIVE: Interpretation of thyroid ultrasonography for assessing goiter prevalence requires valid reference criteria from iodine-sufficient populations. Reports have suggested the current reference criteria for thyroid volume (T(vol)) of WHO/ICCIDD (International Council for the Control of Iodine Deficiency Disorders) may be too high. Our objective was to determine if inter-observer and/or inter-equipment variability contributes to the disagreement in sonographic T(vol) in children reported from iodine-sufficient areas. DESIGN: A 2-day workshop in which four experienced ultrasound examiners from around Europe measured T(vol) in 45 6--12-year-old Swiss schoolchildren using four different portable ultrasound machines. One of the participating examiners (observer A) had generated the T(vol) data in European children that are the basis for the WHO/ICCIDD reference criteria. METHODS: Sonographic T(vol) was measured in each child by all four examiners on all four machines. Six hundred and eighty-four examinations were completed, with examiners having no knowledge of one another's results. Inter-observer and inter-equipment variation was calculated. RESULTS: Mean inter-equipment variation in T(vol) was 15.2% (95% CI: 14.1, 16.3%). There were no significant differences in T(vol) between equipment (P=0.51). For all observers, the mean inter-observer variation in T(vol) was 25.6% (95% CI: 23.9, 27.2%). At all ages and all body surface areas, there was a large systematic measurement bias (+30% volume) between the mean T(vol) of observer A and the mean Tvol of observers B, C and D. Reanalysis using data from observers B, C and D reduced the mean inter-observer variation in T(vol) to 13.3% (95% CI: 11.9, 14.7%). A correction factor for the systematic difference of operator A for the P50 and P97 of T(vol) was estimated using analysis of covariance. When applied to the WHO/ICCIDD reference data, it sharply reduced the discrepancy between the WHO/ICCIDD criteria and those from other iodine-sufficient children around the world. CONCLUSIONS: Inter-equipment error contributes minimally to reported differences in sonographic T(vol). Even among experienced examiners, inter-observer variation in sonographic T(vol) in children can be high, and probably contributes to the current disagreement on normative values in iodine-sufficient children. A systematic bias at least partially explains why the WHO/ICCIDD reference data differ from those reported from other iodine-sufficient children around the world. The findings argue strongly for the standardization of methods used for sonographic measurement of T(vol) in children.

Delange F, Van Onderbergen A, Shabana W, Vandemeulebroucke E, Vertongen F, Gnat D, Dramaix M. · International Council for Control of Iodine Deficiency Disorders (ICCIDD), Brussels, Belgium. · Eur J Endocrinol. · Pubmed #10913937 links to  free full text

Abstract: OBJECTIVE: Belgium is one of the Western European countries in which no program of iodine-deficiency correction using iodized salt has been implemented, in spite of well-documented mild iodine deficiency. In 1995, the median urinary iodine concentration was 55 microg/l (normal: 100-200) and the prevalence of goiter was 11% (normal: below 5%) in representative samples of schoolchildren aged 6-12 years. Based on these results, the authors of the present study and others had emphasized to health professionals and to the public the necessity for iodine supplementation. The objective of this study was to evaluate as to whether these efforts had resulted in an improvement in the status of iodine nutrition. DESIGN: We performed a national survey of the status of iodine nutrition in Belgium based on the determination of thyroid volume, obtained by ultrasonography, and urinary iodine concentrations in schoolchildren. METHODS: A mobile van equipped with an ultrasound instrument, a computer and a deep-freeze visited 23 schools selected from across the country. The sample included 2855 schoolchildren (1365 boys and 1490 girls) aged 6-12 years. RESULTS: The results show a homogeneous situation in the whole country, with a median urinary iodine concentration of 80 microg/l and a goiter prevalence of 5.7%. Urinary iodine slightly decreases with age in girls and reaches a critical value of 59 microg/l at the age of 12 years, together with a goiter prevalence of 18.4%. CONCLUSION: Iodine nutrition has improved slightly in Belgium but mild iodine deficiency continues, with public-health consequences. The improvement indicates silent iodine prophylaxis, as no official salt-iodization measures have been taken. Silent iodine prophylaxis only partly corrects iodine deficiency in Western Europe. Active measures, including the implementation of a program of salt iodization, are urgently required.

Heinrichs C, Parma J, Scherberg NH, Delange F, Van Vliet G, Duprez L, Bourdoux P, Bergmann P, Vassart G, Refetoff S. · Hôpital Universitaire des Enfant Reine Fabiola, Brussels, Belgium. · Thyroid. · Pubmed #10884185 No free full text.

Abstract: We report a Belgian girl born in 1983 with isolated thyrotropin (TSH) deficiency. Hypothyroidism without goiter was diagnosed at the age of 2 months, with extremely low total thyroxine (T4) at 0.3 microg/dL (4 nmol/L; N[normal]: 5.6-11.4 microg/dL). Basal TSH, only moderately elevated at 14.8 mU/L (N: 0-5.3; competitive radioimmunoassay, RIA), increased to 18.2 mU/L after thyrotropin-releasing hormone (TRH) stimulation, whereas prolactin increased normally. At age 15 years, after withdrawal of levothyroxine (LT4) therapy for 6 weeks, TRH stimulation slightly increased serum TSH using two immunometric assays, from less than 0.03 to 0.07 and from 0.2 to 0.3 (a monoclonal and polyclonal antibody), and from 1.9 to 4.1 mU/L using a polyclonal TSH antibody and iodinated recombinant TSH. Sequencing of the TSH-beta subunit gene revealed a homozygous single nucleotide deletion in codon 105 producing a frame shift that results in a truncated TSH-beta with nonhomologous 9 carboxyterminal amino acids and a loss of the 5 terminal residues. This mutation was previously reported in one Brazilian and two German families. The abnormal, and presumably biologically inactive, TSH can be detected in serum using appropriate antibodies. Its relatively small amount in serum is due to either reduced secretion or rapid degradation. The occurrence of the same mutation in three families of different ethnic origin suggests that this mutation may be prevalent in the population. Common ancestry or de novo mutations in a hot spot cannot be excluded. Finally, we must be aware that neonatal screening of congenital hypothyroidism based on blood spot TSH measurement will not detect this rare but severe genetic defect.

Delange F. · ICCIDD, Brussels, Belgium. · Acta Paediatr Suppl. · Pubmed #10626571 No free full text.

Abstract: In conditions of iodine deficiency, the frequency distribution of neonatal thyroid-stimulating hormone (TSH) is shifted towards elevated values. Elevated serum TSH in the neonate indicates insufficient supply of thyroid hormones to the developing brain, and therefore constitutes the only indicator that allows prediction of brain damage, which is the main complication of iodine deficiency. This paper reviews studies on neonatal thyroid function in iodine deficiency and confirms the former statement by WHO/UNICEF/ICCIDD that the frequency of neonatal TSH above 5 mU/L blood is below 3% in conditions of normal iodine supply, that a frequency of 3-19.9% indicates mild iodine deficiency and that frequencies of 20-39.9% and above 40% indicate moderate to severe iodine deficiency, respectively. Neonatal thyroid screening appears as a particularly sensitive index in the monitoring of iodine supply at a population level.

Delange F, de Benoist B, Alnwick D. · International Council for Control of Iodine Deficiency Disorders, Brussels, Belgium. · Thyroid. · Pubmed #10411116 No free full text.

Abstract: Biochemical signs of hyperthyroidism, or even overt and possibly lethal clinical hyperthyroidism were reported in 2 severely iodine-deficient African countries (Zimbabwe and Democratic Republic of Congo, RDC) soon after the introduction of iodized salt. The 2 countries had access to iodized salt produced in Botswana, as well as 5 other countries in the region, namely Cameroon, Nigeria, Kenya, Tanzania, and Zambia. Therefore, a multicenter study was conducted in these 7 countries to evaluate whether the occurrence of iodine-induced hyperthyroidism (IIH) after the introduction of iodized salt was a general phenomenon or corresponded to specific local situations in the 2 affected countries. Two or 3 areas with a past history of severe iodine deficiency that had recently been supplemented with iodized salt were selected in each of the 7 countries. The prevalence of goiter was determined in 4423 schoolchildren in these areas and the concentration of urinary iodine in 2258. Salt factories and health structures were visited for the evaluation of the quality of iodized salt and the possible occurrence of IIH. The study showed that iodine deficiency had been eliminated in all areas investigated, and that the prevalence of goiter had markedly decreased since the introduction of iodized salt. This is a remarkable achievement in terms of public health. However, some areas were now exposed to iodine excess due mostly to a poor monitoring of the quality of the iodized salt and of the iodine intake of the population. In these areas or countries, IIH occurred only when the introduction of iodized salt had been of recent onset (<2 years), namely in Zimbabwe and RDC. In conclusion, the risk of IIH after correction of iodine deficiency is closely related to a recent excessive increment of iodine supply.