Goiter prevalence and urinary iodine status in urban and rural/mountain areas of Piedmont region

Piedmont region was reported in the 70s as a mild iodine-deficient area with a goiter prevalence > 10%. This study aimed at characterizing the current status of iodine deficiency in Piedmont, with special attention to putative differences between urban and rural/mountain areas. A cross-sectional, observational study was performed according to the surveillance methods for iodine deficiency disorders recommended by the World Health Organization (WHO). Ultrasound local thyroid volume reference values and median urinary iodine concentration were obtained in 2178 schoolchildren aged 11-15 yr, resident in Piedmont region for more than 5 yr to assess both goiter prevalence and iodine intake. Anamnestic and anthropometric data, thyroid volume by both bimanual palpation and ultrasound were assessed, and spot urinary iodine samples were collected. The median urinary iodine concentration was 115.8 microg/l and the prevalence of goiter 3.1%, indicating this area as iodine-sufficient. Nevertheless, 39% of the schoolchild population had urinary iodine levels < 100 microg/l and 6.8% < 50 microg/l. No differences in goiter prevalence and median urinary iodine excretion were observed between urban and rural/ mountain populations. In conclusion, Piedmont is now an iodine-sufficient region. As no programs of salt iodization have been carried out in the last 30 yr, a silent iodine replacement has occurred. Despite a sufficient median urinary iodine excretion, a program of iodine prophylaxis is strongly recommended due to a large part of iodine-deficient population.     

Thyroid autoimmunity is associated with higher urinary iodine concentrations in an iodine-deficient area of Northwestern Greece.

Northwestern Greece was identified in the 1960s for its high prevalence of endemic goiter and iodine deficiency. Although iodized salt has been commercially available since then, a recent epidemiological survey of 3916 schoolchildren found that low-grade goiter is still prevalent in endemic proportions (21%). The aim of this study was to further assess the cause of goiter and the severity of iodine deficiency in children from this endemic area of Greece. Of the 800 children with clinically detectable goiter, 97 children (60 girls and 37 boys, 8-15 years) were recruited for determination of urinary iodine excretion, as well as assessment of thyroid volume and function and detection of antithyroid antibodies. The median urinary iodine concentration was 8.4 microg/dL, indicative of a mild iodine deficiency. Thyroid function was normal in all but 11 children who had subclinical hypothyroidism. Sixteen children (16.5%), including all those with subclinical hypothyroidism, were positive for antithyroid antibodies. Their median urinary iodine concentration (20.6 microg/dL) was higher compared to children who were negative for antibodies (7.4 microg/dL; p<0.001). The mean thyroid volume by ultrasonography (12.2+/-4.1 mL) was above the upper limit of normal for this age group. Thyroid volume was inversely related to the urinary iodine content in the children with negative antithyroid antibodies. Iodine deficiency is still prevalent in northwestern Greece although of mild severity and constitutes the primary cause of goiter among schoolchildren. However, it appears that autoimmune thyroiditis is emerging as a frequent cause of goiter in those children with sufficient iodine intake.     

Epidemiological survey of thyroid volume and iodine intake in schoolchildren,postpartum women and neonates living in Ulaan Baatar

OBJECTIVE: Although endemic goiter had been recognized in most parts of the country, there are few available data on iodine-deficiency disorders (IDDs) in Mongolia. This study aimed to characterize the current status of iodine deficiency in Ulaan Baatar, Mongolia's capital city. DESIGN: Cross-sectional, observational study designed and performed according to the surveillance methods for IDD prevalence recommended by WHO/UNICEF/ICCIDD. SUBJECTS: A total of 505 schoolchildren aged 9-14 years (237 girls and 268 boys) and 138 mothers and their neonatal infants were selected to clinical and biochemical examination of the thyroid in 1996 and 1999. MEASUREMENTS: The anthropometric measurements, thyroid volume determined by ultrasound, blood TSH and FT4 concentrations, urinary iodine concentration and iodine content of salt consumed in households. RESULTS: Median thyroid volumes based on age were generally higher than those in iodine-sufficient areas and comparative to those reported in mild iodine-deficiency areas. Application of the updated WHO/ICCIDD reference values in iodine-replete European schoolchildren to the Mongolian children aged 10-12 years resulted in a goiter prevalence of 43.3%. The median value of urinary iodine concentration was 152.5 micro g/l (1.20 micro mol/l) and 40.3% of children excreted iodine below 100 micro g/l. Iodized salt (> 40 ppm) was consumed in 63.1% of households and in the children using noniodized salt their urinary iodine concentration was lower than those using ionized salt. In postpartum women, median thyroid volume and urinary iodine concentration were 11.3 ml and 107 micro g/l (0.84 micro mol/l), respectively, and 46% of women excreted less than 100 micro g/l (0.79 micro mol/l) of iodine. Of their neonates, 17.8% had elevated blood TSH levels (> 5 mU/l). In a 1999 survey, the goiter prevalence and ratio of low iodine excretion in schoolchildren decreased to 29.8% and 31.3%, respectively, while median urinary iodine concentration remain unchanged (160 micro g/l; 1.26 micro mol/l). CONCLUSION: The present study clearly indicates the presence of mild iodine deficiency in Mongolia. Enlarged thyroid gland and normal iodine excretion observed in schoolchildren living in Ulaan Baatar may result from the residual effects of iodine deficiency previously and presumably still exist in the city. Slight reduction in the rate of children with enlarged thyroid and low urinary iodine excretion after the onset of national iodinization programme suggests incomplete normalization of thyroid volume in children and that the correction of iodine deficiency is now in progress in Ulaan Baatar. Further nationwide surveys together with monitoring the progress of the national programme eliminating IDD are required in suburban areas surrounding the city and also in rural areas.     

Thyroid volume and urinary iodine excretion in the schoolchild population of a Northwestern Italian sub-Alp metropolitan area

Iodine deficiency is recognised as a major preventable public-health worldwide problem. The aim of this study is to assess local reference values for thyroid volume, and give a snapshot of the epidemiology of goiter and iodine nutritional status of the Turin schoolchild population. Sonographic thyroid volume and median urinary iodine excretion were obtained in 1067 schoolchildren aged 11-15 yr resident in Turin for more than 5 yr to assess both goiter prevalence and iodine intake. All the subjects were asked to fill in a questionnaire about their life habits. Anamnestic and anthropometric data, thyroid volume by both bimanual palpation and ultrasonography were assessed, and spot urinary iodine samples were collected. The results show that the median urinary iodine concentration is 113.1 microg/l and the prevalence of goiter <5%, indicating this area as iodine-sufficient. Nevertheless, 40.5% of the schoolchild population has urinary iodine levels lower than the cut-off level recommended as iodine-sufficiency. Interestingly, the high relative prevalence of ultrasound features of autoimmune thyroid disease suggests autoimmune-thyroiditis as a frequent thyroid disease in Turin schoolchildren. As no active programs of salt, milk or water iodisation have ever been carried out, a silent iodine prophylaxis has probably occurred in the city. Despite a sufficient median urinary iodine excretion, a focused program of iodine prophylaxis should be developed due to the presence of a large rate of iodine-deficient population.     

Iodine deficiency in Azerbaijan after the discontinuation of an iodine prophylaxis program: reassessment of iodine intake and goiter prevalence in schoolchildren.

The goal of this study was to assess the prevalence of iodine deficiency (ID) in Azerbaijan after the discontinuation of an iodine prophylaxis program by assessing the prevalence of goiter, iodine intake, and thyroid function. The study included 942 schoolchildren (475 boys and 467 girls) ages 8-14 years, from 13 distinct regions. The survey included the following: (1) clinical evaluation; (2) assessment of thyroid volume both by ultrasound and by palpation; (3) determination of iodide in a morning urine specimen using the classic Sandel-Kolthoff reaction in 347 schoolchildren; (4) determinations of thyrotropin (TSH), triiodothyronine (T3), thyroxine (T4), thyroglobulin (Tg), and anti-thyroid peroxidase (TPO) in serum (n = 165) and TSH in whole blood spotted on filter paper (n = 942). The prevalence of goiter for the whole country was determined by ultrasound (US) to be 86% and by palpation 66%, reaching 100% in the mountainous regions of Caucasus. The median urinary iodine excretion (UIE) was 54 microg/L, reaching level of 26 and 39 microg/L in the Caucasus region. In conclusion, according to the World Health Organization (WHO) classification, Azerbaijan now has mild to moderate ID (median UIE, 54 microg/L) and in the mountainous regions with severe ID. The high prevalence of goiter and the low UIE emphasizes the need for urgent medical reintervention. An iodination program is now implemented by our team in the mountainous regions under the auspice of the government of Azerbaijan.     

A programme of iodine supplementation using only iodised household salt is efficient--the case of Poland

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.     

A survey of iodine intake and thyroid volume in Dutch schoolchildren: reference values in an iodine-sufficient area and the effect of puberty

BACKGROUND: Iodine deficiency and endemic goiter have been reported in the past in The Netherlands, especially in the southeast. OBJECTIVE: To evaluate iodine intake and thyroid size in Dutch schoolchildren, contrasting those living in a formerly iodine-deficient region in the east (Doetinchem) with those living in an iodine-sufficient region in the west (Amsterdam area). DESIGN: Cross-sectional survey of 937 Dutch schoolchildren aged 6--18 years, of whom 390 lived in the eastern and 547 in the western part of the country. METHODS: Thyroid size was assessed by inspection and palpation as well as by ultrasound. Iodine intake was evaluated by questionnaires on dietary habits and by measurement of urinary iodine concentration. RESULTS: Eastern and western regions were similar with respect to median urinary iodine concentration (15.7 and 15.3 microg/dl, NS, Mann-Whitney U test), goiter prevalence by inspection and palpation (0.8 and 2.6%, P=0.08, chi-squared test), and thyroid volumes. The P97.5 values of thyroid volumes per age and body surface area group were all lower than the corresponding sex-specific normative WHO reference values. Iodized salt was not used by 45.7% of households. Daily bread consumption was five slices by boys and four slices by girls. Weekly milk consumption was 3 liters by boys and 2 liters by girls. Seafish was consumed once monthly. From these figures we calculated a mean daily iodine intake of 171 microg in boys and 143 microg in girls, in good agreement with the measured median urinary concentration of 16.7 microg/dl in boys and 14.5 microg/dl in girls. The sex difference in iodine excretion is fully accounted for by an extra daily consumption of one slice of bread (20 microg I) and one-seventh of a liter of milk (8.3 microg I) by boys. Thyroid volume increases with age, but a steep increase by 41% was observed in girls between 11 and 12 years, and by 55% in boys between 13 and 14 years, coinciding with peak height velocity. Girls have a larger thyroid volume at the ages of 12 and 13 years, but thyroid volume is larger in boys as of the age of 14 years. CONCLUSIONS: (1) Iodine deficiency disorders no longer exist in The Netherlands. (2) Bread consumption remains the main source of dietary iodine in The Netherlands; the contribution of iodized table salt and seafish is limited. (3) The earlier onset of puberty in girls renders their thyroid volume larger than in boys at the age of 12--13 years, but boys have a larger thyroid volume as of the age of 14 years.     

Iodine deficiency in Calabria: characterization of endemic goiter and analysis of different indicators of iodine status region-wide

The distribution of goiter prevalence in schoolchildren (no.=13,984, age 6-14 yr), the neonatal TSH results obtained from the congenital hypothyroidism screening program and the urinary iodine excretion values (no.=284) were employed for the assessment of iodine deficiency in Calabria, a Southern Italy region. Data were collected during the years 1990-1996. In the inland territory, goiter prevalence ranged from 19 to 64%. At sea level, there was a great variability of goiter prevalence, with values varying from 5.3 to 25.7%. The analysis of the neonatal hypothyroidism screening program data (no.=21,078) showed a 14.8% frequency of TSH levels >5 microU/ml whole blood in newborns from the inland territory and a 14.1% frequency at sea level. Urinary iodine excretion resulted (mean+/-SD) 53.8+/-43.4 microg/l (range: <20 to 189 microg/l) in the inland territory and 89.6+/-59.8 microg/l (range: 26 to 333 microg/l) at sea level. Median urinary iodine excretion values in 13 villages or small towns of the inland territory ranged from 31 to 57 microg/l. In 2 major towns located at sea level, the median iodine excretion values were 72 microg/l in Crotone main city and 94 microg/l in Reggio Calabria main city. The data indicated that moderate, with pockets of severe iodine deficiency is present in the inland region while iodine supply varies from sufficient to marginally low in the coastal areas. Mild iodine deficiency was found in a major town located at sea level.     

Iodine supplementation in Austria: methods and results.

Until 1963 Austria was an extremely iodine-deficient area with low iodine intake and high goiter prevalence. Therefore, for the first time in 1963, salt iodination with 10 mg of potassium iodide per kilogram of salt was introduced by federal law. Twenty years after this salt iodination, however, investigations in schoolchildren demonstrated iodine deficiency grade I to II according to the World Health Organization (WHO) (urinary iodine excretion, 42-75 microg/g Crea) and goiter prevalence of far more than 10%. In 1990, salt iodination was increased to 20 mg of potassium iodide per kilogram of salt. In 1994, further investigations in schoolchildren demonstrated an increase of urinary iodine excretion (121 microg/g Crea) and a reduction of goiter prevalence below 5%, with the exception of pupils ages 14-19 (12%). In the year 2000, 10 years after the increase of salt iodination in Austria, 430 nonselected adult inhabitants of three communities in Carinthia (a county of Austria) were investigated for iodine excretion, goiter prevalence, and prevalence of thyroid autoantibodies. This study demonstrated that although iodine supply is sufficient now in Austria (males, 163.7 microg of Crea; females, 183.3 microg of iodine per gram of Crea), goiter prevalence is still high in the elderly, who lived for a longer period of iodine deficiency (34.3% in women and 21.3% in men), whereas goiter prevalence in younger people up to age 40 years is below 5%. It could also be shown that the percentage of thyroid autoantibodies is now as high as in other countries with sufficient iodine supply (3.19% in males, 5.17% in females). In addition to the changes of urinary iodine excretion and goiter prevalence because of salt iodination, changes of incidence in hyperthyroidism and histologic types of thyroid cancer are discussed in this paper. In conclusion, the introduction of salt iodination led to an improvement in iodine supply with a marked reduction of goiter prevalence in people who were born after 1963, but also to an increase in hyperthyroidism and autoimmune thyroid diseases as well as changes in histologic types of thyroid cancer.     

Sustainable control of iodinedeficiency in Iran: beneficial results of the implementation of the mandatory law on salt iodization

Iodine deficiency disorders (IDD) were prevalent in the Islamic Republic (IR) of IRAN before 1989, when the national salt iodization program with 40 mg l/k of salt was initiated. Despite a comprehensive IDD control program, less than 50% of the households in rural areas consumed iodized salt by 1994. A law for the mandatory production of iodized salt for households was passed in 1994. The purpose of this study was to evaluate goiter status and urinary iodine excretion 2 yr after this law was implemented. In each of 26 provinces, 30 groups of 40 schoolchildren, total 36,178, were examined for goiter and classified according to World Health Organization (WHO) classification. Urinary iodine excretion was measured in 2,917 children by digestion method. Goiter was endemic in all provinces, but the majority were small (grade 1) goiter. Median urinary iodine was 20.5 microg/dl 85.1% had urinary iodine > or =10 microg/dl. Median urinary iodine was above 13 microg/dl in all 26 provinces. In all provinces the percentage of schoolchildren with urinary iodine <5 microg/dl was less than 16%. In nine provinces the median urinary iodine was between 13 to 20 microg/dl; urinary iodine of their schoolchildren was <5 microg/dl in 10.8% and <2 microg/dl in 6-9%. No significant difference was observed between boys and girls or children of rural and urban regions in urinary iodine excretion. We conclude that 7 yr after the beginning of salt iodization and 2 yr following mandatory iodized salt consumption, urinary iodine excretion is adequate in schoolchildren; considering the data of the percent of households consuming iodized salt and programmatic setting of the IDD program, The IR of Iran has reached a sustainable control program for iodine deficiency.     

Effect of iodine supplementation on a pediatric population with mild iodine deficiency.

A cross-sectional study in two stages consisted of healthy children to assess the effect of iodine supplementation on a pediatric population with mild iodine deficiency in an ongoing program in the Province of Pontevedra, northwestern Spain. In the first survey (1984), 1565 schoolchildren and in the second survey (1995) 907 schoolchildren were randomly selected from the population. In January 1985, a mandatory consumption of iodized salt in our region was begun. In both surveys we studied prevalence of goiter, urinary iodine excretion, and prevalence of thyroid dysfunction. Similar prevalences of goiter were observed in both surveys, 3.7% versus 3.9%; however, significantly lower prevalence of Ib and II degree goiters were observed in the second survey. The mean iodine excretion was 88.6 +/- 73 microg/L (median 66.3) and 146.4 +/- 99 microg/L (median 115.7), p < 0.01 for the first and second surveys, respectively. Finally, the overall prevalence of thyroid dysfunction was similar in both surveys, 9.2% versus 7.0%; however, significantly lower prevalence of suppressed serum thyrotropin (TSH), considered as a marker of subclinical hyperthyroidism, was observed in the second survey when compared to the first, 0.1% versus 2%, p < 0.01. Our results are in agreement with the recent data from Denmark, where the prevention of subclinical hyperthyroidism occurring in the elderly as a consequence of longstanding mild iodine deficiency is the reason that the Danish finally started iodine supplementation on a national basis. In conclusion, long-term correction of mild iodine deficiency in a pediatric population has beneficial effects on the prevalence of high-degree goiters, and this correction reduces significantly the prevalence of subclinical hyperthyroidism. The present observation constitutes a strong argument for correcting even mild iodine deficiency.     

Epidemiological survey on the relationship between different iodine intakes and the prevalence of hyperthyroidism

OBJECTIVE: To investigate the effect of different levels of iodine intake on the prevalence of hyperthyroidism and the impact of universal salt iodization on the incidence of hyperthyroidism. DESIGN: A comparative cross-sectional and longitudinal survey was conducted in three areas with borderline iodine deficiency, mild iodine excess (previously mild iodine deficiency) and severe iodine excess. Universal salt iodization had been introduced 3 years previously except in the area with borderline iodine deficiency. METHODS: In total 16 287 inhabitants from three areas answered a questionnaire concerning the history of thyroid disease. Among them 3761 unselected subjects received further investigations including thyroid function, thyroid autoantibodies, thyroid ultrasonography and urinary iodine excretion. RESULTS: Among areas with median urinary iodine excretion of 103 microg/l, 375 microg/l and 615 microg/l (P<0.05), the prevalence of hyperthyroidism did not differ significantly (1.6%, 2% and 1.2%). The prevalence of subclinical hyperthyroidism was higher in areas with borderline iodine deficiency and mild iodine excess than in the area with severe excess iodine intake (3.7%, 3.9% and 1.1%, P<0.001). The prevalence of Graves' disease and its proportion in hyperthyroidism did not differ among areas. The incidence of hyperthyroidism did not significantly increase after the introduction of universal salt iodization. CONCLUSION: Different iodine intakes under a certain range do not affect the prevalence and type of hyperthyroidism. Subclinical hyperthyroidism is more prevalent in the iodine deficient area than in the severe iodine excessive area. In the area with mild iodine deficiency, the introduction of universal salt iodization may not be accompanied by an increased incidence of hyperthyroidism.     

High prevalence of autoimmune thyroiditis in schoolchildren after elimination of iodine deficiency in northwestern Greece.

The current iodine status and the impact of silent iodine prophylaxis on the prevalence of autoimmune thyroiditis among schoolchildren in a formerly iodine-deficient community in northwestern Greece, were investigated. The findings were compared to those obtained from a similar survey conducted 7 years previously in the same area. A total of 302 schoolchildren (12-18 years of age) from a mountainous area of northwestern Greece were examined for the presence of goiter, and blood and urine samples were collected for assessment of thyroid function, antithyroid antibodies and urinary iodine excretion. In those children (n = 42) with palpable goiter or positive antibodies and/or a thyrotropin (TSH) level greater than 5 mU/L, thyroid ultrasonography was performed to estimate thyroid gland size and morphology. Median urinary iodine concentration in the children was 20.21 microg/dL, indicating sufficient iodine intake. Thyroid function was normal in all but 7 children, who had subclinical hypothyroidism (2.5%). Antithyroid antibodies (antithyroid peroxidase [TPO] and/or antithyroglobulin [Tg]) were positive in 32 children, including those with subclinical hypothyroidism (10.6%). Twenty-nine of these children (9.6%) also had the characteristic echo pattern of thyroiditis on ultrasound and were diagnosed to have autoimmune thyroiditis. In comparison to data from our previous survey 7 years ago, there has been a threefold increase in the prevalence of autoimmune thyroiditis among schoolchildren. In conclusion, silent iodine prophylaxis has resulted in the elimination of iodine deficiency in Greece, and this has been accompanied by an increase in the prevalence of autoimmune thyroiditis.     

Attention to the hiding iodine deficiency in pregnant and lactating women after universal salt iodization: A multi-community study in China

BACKGROUND: Monitoring of iodine nutrition depends chiefly on the urinary iodine concentration in representative samples from the population. International groups have recommended school-age children as a convenient group for surveys, because of their accessibility and young age, but the relevance of this group to others, especially pregnant women, is not well established. OBJECTIVE: The purpose was to compare different approaches to assessing iodine nutrition within communities, especially for pregnant and lactating women. DESIGN: In an urban and a rural site from each of the 11 Chinese provinces, covering a wide geographic and socioeconomic range, we measured the iodine content of household salt and drinking water, the thyroid volume in school children, and the urinary iodine concentration in five population subsets; in some sites we also assessed iodine in breast milk and thyroid size in adult women. RESULTS: The median urinary iodine concentrations for pregnant and lactating women were well below those of the schoolchildren from the same community in most study sites, the difference between medians, at overall level, being about 50 microg/l for the pregnant and 40 microg/l for the lactating, respectively. When ranked by median urinary iodine concentrations at overall level, the order of the groups was: all infants, schoolchildren, women of childbearing age, lactating women and pregnant women in both urban and rural sites. This relative distribution was constant among the study sites. From it, we derived a relationship to predict the median values for other groups, based on the data of schoolchildren. The median iodine content of salt was 30.9 ppm in urban sites and 31.3 ppm in rural sites, respectively, close to the nationally mandated 35 mg/kg. Water had low iodine content (3.7 microg/l) in both urban and rural sites except in a rural site from Tianjin. Ultrasonography showed that 6.5% of 1329 children in urban sites and 5.3% of 1431 children in rural sites had thyroid enlargement. Breast milk had a median iodine content of 135.9 microg/l in the urban and 157.5 microg/l in the rural. The goiter prevalence by palpation was low (2.0%) among all women examined (3367), but higher in pregnant women (2.7%) than in lactating women or other adult women. CONCLUSIONS: An effective iodized salt program has brought iodine sufficiency to most of China, but pregnant women in some areas may still risk deficiency and need further supplements. We suggest other countries and international agencies pay more attention to pregnancy, where iodine deficiency has its worst consequences.     

Prevalence of goiter among schoolchildren from Gorgan, Iran, a decade after national iodine supplementation: association with age, gender, and thyroperoxidase antibodies

BACKGROUND: One decade after universal salt iodization in Iran, goiter prevalence, urinary iodine concentration (UIC) and thyroperoxidase antibody (TPOAb) values were assessed among schoolchildren in Gorgan, Iran. METHODS: From 2003-2004, 500 girls and 900 boys aged 7-11 yr were evaluated for goiter by palpation. UIC was measured in 183 randomly-selected goitrous children. Serum TSH, T4, and TPOAb were measured in 53 goitrous and 30 non-goitrous children with adequate UIC. RESULTS: Goiter was detected in 370 (26.4%) children. Goiter was present in 31% of girls and 17% of boys age 9 (p<0.012); 37% of girls and 20% of boys age 10 (p<0.003); and 52% of girls and 19% of boys age 11 (p<0.0001). Median (range) UIC for all goitrous children sampled was 190 (20-600) microg/l; 220 (30590) in boys and 170 (20-600) in girls (p=0.001). Eight point seven percent of goitrous children and 22% of goitrous girls aged 10-11 had UIC<100 microg/l, while 47% of the goitrous children had UIC> or =200 microg/ l. TPOAb was present in 52.8% of goitrous children and 10% of non-goitrous children (p=0.0001). TPOAb was present in 53.9% of 10-11 and 22.7% of 7-9 yr old goitrous and non-goitrous children (p=0.003) with adequate UIC. Median (range) TSH was 2.9 (0.3-10.9) mlU/I in TPO-positive and 1.8 (0.5-4.1) in TPO-negative children (p=0.001). CONCLUSIONS: Gorgan, Iran, is an iodine-sufficient area and almost half of schoolchildren have more than adequate UIC. TPOAb is associated with endemic goiter. Despite sufficient UIC overall, some school-aged girls remain at risk of iodine deficiency.     

Normal values for thyroid ultrasonography, goiter prevalence and urinary iodine concentration in schoolchildren of the Veneto Region, Italy

Goiter prevalence in school-age children and median urinary iodine concentration (UIC) are the main indicators of iodine deficiency in a population. In areas of mild iodine deficiency, where goiters are small, ultrasound is preferable to physical examination to estimate goiter prevalence. The World Health Organization (WHO) has adopted thyroid volume ultrasonography results from a survey of European schoolchildren as an international reference, but these values have recently been questioned. The aims of the study were: a) to determine regional normal echographic reference values of thyroid volume in children aged between 11 and 14 yr in the Veneto Region, in North-East Italy; b) to determine goiter prevalence by physical and ultrasonographic examination; c) to determine UIC in this section of the population. A cross-sectional study was carried out on 1730 schoolchildren, aged between 11 and 14, living in towns in low-lying areas, in the valleys of the pre-Alps and in the mountains between 600 and 1200 m. Thyroid volume was evaluated by inspection and palpation using the WHO criteria. In 560 children thyroid volume was determined by ultrasound. UIC was measured in 1368 children. On physical examination a grade I goiter was found in 7.5% of children. No goiter grade II or grade III was found. The regional thyroid volume reference values by ultrasonography were similar, or slightly lower (5-20%), to the corresponding WHO reference values. Mean UIC was 148 +/- 110 microg/l, with no difference between lowlands and uplands; UIC values less than 100 microg/l were found in about 30-35% of the children. UIC was higher in children using iodized salt than in non-users. No correlation was found between thyroid volume by ultrasonography and UIC. Thyroid volume was found to be bigger in upland children than in those in low-lying areas, probably because of low iodine intake in people living in the mountains in previous generations. This data show that Veneto is not a iodine-deficient area, with no presence of endemic goiter. However, the great number of children with a UIC of less than 100 microg/l also suggests the use of iodized salt in the Veneto Region.     

Evaluation of goiter endemia by ultrasound in schoolchildren in Val Sarmento (Italy).

Ultrasonography is an excellent and objective method for assessing thyroid volume, especially in children where clinical evaluation is inaccurate. The aim of this study was to evaluate the presence of goiter by thyroid ultrasound and palpation in 244 schoolchildren, 6 to 14 years old, living in some rural villages of Val Sarmento, a mountain area of Basilicata, Italy. In 1996 we revealed the presence of endemic goiter in 25% of the schoolchildren evaluated by palpation, according to World Health Organization (WHO) criteria, and in 15.9% of the schoolchildren evaluated by ultrasonography (7.5 MHz linear probe). The median urinary iodine excretion, taken from an extemporaneous sample of the first urines in the morning, was 62.2 microg/l. This study includes Val Sarmento, an area with mild-moderate grade (Grade I) of iodine deficiency, suggesting the need for iodine prophylaxis. Furthermore, it proves that the measurement of thyroid volume by ultrasonography is an essential instrumental method for a correct epidemiological study of endemic goiter, particularly in areas where there is mild iodine deficiency.     

The ThyroMobil model for standardized evaluation of iodine deficiency disorder control in Indonesia.

Indonesia used to be affected by varying degrees of iodine deficiency. Salt iodization has been the adopted strategy on a national basis since 1979. The prevalence of goiter in school-age children (SAC) determined by palpation subsequently markedly decreased within the next 15 years. The objective of the present work was to perform an updated evaluation of the status of iodine nutrition in Indonesia by using standardized methods for the measurement of thyroid volume by ultrasounds and the concentration of urinary iodine in SAC. The survey included 7,447 SAC ages 6 to 12 years from 129 sites selected by multistage and stratified sampling in five provinces (4 in Java plus Sumatra and the Province of Bali). A mobile unit (ThyroMobil van) equipped with a sonographic device and facilities for the collection of urine samples visited all sites. In Java plus Sumatra, the median urinary iodine was 195 microg/L. Thirty-four percent of the values were within normal limits (between 100 and 200 microg/L); 17.2% were below 100 microg/L and 48.8% were above 200 microg/L, including 18.2% above 300 microg/L and 0.7% above 1000 microg/L. In Bali, the median was 81 microg/L with 58.3% of the values below 100 microg/L and only 14.7% of the values above 200 microg/L. The prevalence of goiter determined by ultrasounds and using the World Health Organization/International Council for Control of Iodine Deficiency Disorders (WHO/ICCIDD) normative values for gender and age was 3.0% in Java plus Sumatra and 1.9% in Bali. The values were 8.0% and 12.5%, respectively, when using reference values for Indonesia established during the present survey in an iodine replete area in central Java. In conclusion, (1) iodine deficiency has been eliminated in large parts of Indonesia; (2) Bali is still affected by mild iodine deficiency; (3) in many places, iodine deficiency has been replaced by iodine excess, occasionally potentially toxic; (4) the WHO/ICCIDD normative values for thyroid volume measured by ultrasound in SAC are not valid for Indonesia; (5) in Indonesia, the level of salt iodization could be decreased and the biological monitoring of urinary iodine at the population level should be reinforced and maintained; (6) the ThyroMobil model has, as in other parts of the world, demonstrated its efficiency in the organization of partnership evaluation and monitoring of iodine nutrition, as well as in social mobilization.     

Recurrent iodine deficiency in Tasmania,Australia: a salutary lesson in sustainable iodine prophylaxis and its monitoring

Even mild iodine deficiency during early childhood and pregnancy has the potential to impair neurological development. Often considered a problem of developing nations, a number of industrialized countries are at risk of deficiency. Despite past success with intentional and unintentional iodine fortification, recurrence of deficiency is an ever-present risk. Tasmania, an island state of the Commonwealth of Australia, has a history of endemic iodine deficiency, which was successfully eliminated by iodine prophylaxis initiated in 1950. In this report we describe a formal assessment of iodine nutrition in the Tasmanian population, 50 yr after initiation of the prophylaxis program. The requirements and obstacles to achieving sustainable iodine prophylaxis in an otherwise affluent community are considered. A cross-sectional study was undertaken during the yr 2000. Urinary iodine excretion (UIE) and thyroid ultrasonography were assessed in a representative statewide sample of school-age children. Children (n = 225) aged 4 to 17 yr from throughout Tasmania were studied. The sample comprised 99 girls and 126 boys. The median UIE was 84 microg/liter (87 microg/liter for males and 81 microg/liter for females), with UIE 50 microg/liter or less in 20%. Based on age-specific World Health Organization/International Council for the Control of Iodine Deficiency Disorders normative data for thyroid volume, the prevalence of elevated thyroid volume was 5.3% for boys and 3.5% for girls. However, after correcting the World Health Organization/International Council for the Control of Iodine Deficiency Disorders reference data, the prevalence increased to 24.6% for boys and 20.7% for girls. No significant difference in the thyroid volumes was found between males and females in this study. These data confirm the recurrence of mild iodine deficiency in Tasmania. The failure of sustained iodine prophylaxis highlights the universal importance of persistent surveillance, use of sustainable measures, public awareness, and a specific legislative framework for managing ongoing iodine prophylaxis. Our findings also emphasize the importance of accurate reference data for assessment thyroid volume.     

First beneficial results of the implementation of Croatian new law on salt iodination

Presented pilot-study on urinary iodine excretion among schoolchildren in main geographic regions of Croatia indicates a significant improvement in iodine excretion only 12 months after introduction of a new mandatory salt iodination with 25 mg KI/kg of salt. Measurements of urine iodine excretion in 663 schoolchildren of both sexes, aged 9-16 years, from Zagreb, Rude, Bednja, Osijek, Dakovo, Rijeka, Pazin and Dubrovnik showed that from 77.9% to 94.8% of subjects have had urinary iodine above 5 microg/dl. Also from 41.2% to 70.8% of children have had urinary iodine excretion above 10 microg/dl. Before introduction of a new law mostly borderline values of urinary iodine excretion were recorded; therefore recent values present significant positive shift and actually they are the best signs of almost adequate iodine intake in Croatian youth. Nevertheless, further measures for improvement of iodine intake are recommendable because still 31% of controlled table-salt samples from households and 15.7% of imported salt samples have had KI level below 20 mg/kg of NaCl. Salt produced in Croatia was (Pag and Nin salt plants) completely in accordance with iodination regulations. On the other hand, as recent increase in urinary iodine excretion could not be simultaneously followed by reduction in goiter prevalence, in the following years further epidemiological surveys of iodine deficiency disorders shall be warranted.