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.     

Silent iodine prophylaxis in Western Europe only partly corrects iodine deficiency; the case of Belgium

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.     

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.     

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.     

Thyroid volumes in schoolchildren of the Emirates

Iodine deficiency is a major public health problem, an enlarged goiter being its most apparent manifestation. Recent studies have used US as an accurate and precise method of measuring thyroid size. The aim of this study was to describe thyroid volumes measured by US among school-aged children in the United Arab Emirates. Cross-sectional studies were performed in 4,381 school children, aged 6-17 yr in three locations in the Emirates. Data were collected on age, sex, weight, thyroid size by palpation and US, and urinary iodine. Age/sex and body surface area (BSA) upper limits of thyroid volume were derived. Median urinary iodine in Abu Dhabi, Al Ain and in rural areas of Dubai were 9.9, 12.0 and 9.6 mg/dl respectively. The goiter prevalence by palpation was 28.1%, 26.4% grade 1 and 1.7% grade 2. There was significant difference in median and upper limit of thyroid volumes between boys and girls (p < 0.001). The thyroid volumes of subjects, as assessed by US, progressively increased with age for both sexes (r = 0.53, p < 0.001). In schoolchildren in the Emirates, the best predictors of thyroid volume were BSA, height and weight. The thyroid volumes of the children in this study appear comparable with those reported in a European survey in 1997.     

Iodine deficiency in children 7–19 years old in Eastern Province of Cameroon

Objective  To determine the prevalence of iodine deficiency in children in Eastern Province, Cameroon.
Method  Urinary iodine (I) and thiocyanate (SCN) excretion levels were assessed in 158 children (62 boys and 96 girls) aged 7–19 years.
Results  Mean urinary iodine excretion was 4.49 μg/dl for girls and 4.71 μg/dl for boys, lower than the 5.0 μg/dl minimal value defined by WHO. Overall 64.42% of subjects had urinary iodine excretion below the minimum, more than three times the population percentage (20%) at which a zone is declared endemic. Mean urine SCN concentration and mean I/SCN ratios of the study population were 2.57 ± 1.43 mg/dl and 2.21 ± 1.35 μg/mg for boys and 2.91 ± 1.57 mg/dl and 1.91 ± 1.1μg/mg for girls.
Conclusion  Iodine deficiency remains a problem in Eastern Province of Cameroon.     

Goiter prevalence and urinary iodine concentration in slovenian adolescents.

Context: Slovenian school-age children are, as are more than half of European school-age children, still considered to be iodine deficient. In 1999, supplementation of salt was increased from 10 to 25 mg of KI/kg of salt. Objective: The objective of our study was to determine the success of this intervention. Design and Patients: Twelve hundred sixty-four girls (mean age +/- SD: 15.7 +/- 0.6 years) and 1200 boys (15.8 +/- 0.8 years) representing 10% of all 15-year-old Slovenian adolescents were studied. Thyroid size was estimated by clinical examination in all subjects and by ultrasound when enlarged thyroid was suspected. Thyroid volume was also determined by ultrasound in 108 random iodine-sufficient adolescents. In addition, urinary iodine concentration was determined in all subjects. Results: Enlarged thyroid was determined by clinical examination and ultrasound in 0.9% of all subjects. In randomly selected iodine-sufficient subjects, enlarged thyroid was determined in 4.6%. Median urinary iodine concentration for the population was 140 microg/L. In all regions it was greater than or equal to 100 microg/L. Values less than 50 microg/L were determined in 2.5% of all subjects. Conclusions: Slovenian adolescents are iodine sufficient and the prevalence of goiter is low, indicating that increased KI supplementation of salt in 1999 was successful.     

Urinary iodine and thyroid volume in a Swedish population

OBJECTIVE: To evaluate the present efficacy of an iodine supplementation programme working in Sweden since 1936 by studying the iodine excretion in urine and determining the thyroid volume in a population in a semi-rural community. DESIGN: A cross-sectional population screening comprising three age groups with randomly selected individuals: group 1 (children): 7-9 years, n = 61 (invited 70); group 2 (teenagers): 15-17 years, n = 61 (invited 63), and group 3 (adults): 60-65 years; n = 57 (invited 73). MAIN MEASUREMENTS: Urinary iodine was measured spectrophotometrically; thyroid volume by ultrasonography. RESULTS: The median values for urinary iodine concentration in the three age groups were 194 microg L(-1), 246 microg L(-1) and 190 microg L(-1), respectively, indicating an adequate iodine intake. In the 7-9 year olds, the median value of the thyroid volume was 4.7 mL, which coincides with the recently established upper limit of normal children of that age, 4.0-4.8 mL (ICCIDD, International Council for control iodine deficiency disorders). One eight-year-old boy had a pronounced goiter. Four teenagers and one adult were found to have an enlarged thyroid gland according to earlier established reference volumes (15 years >16 mL; adults > 25 mL). CONCLUSION: We conclude that the iodine intake in our region is sufficient in age groups ranging from young children to pre-retirement adults.     

Echographic evaluation of the thyroid gland and urinary iodine concentration in school children from various regions of the State of São Paulo, Brazil

We have examined, by ultrasonographic studies, the thyroid gland of 844 schoolchildren, aged between 6 and 14 years old (423 girls, 421 boys). There was a progressive increase of the thyroid volume with aging with a positive and significant correlation with the body surface area. The presence of enlarged thyroid gland was rarely seen, being present in only 1.6% of the studied cohort. A few thyroid gland abnormalities were noticed such as hemiagenesia (4 children), nodules and cysts and hypoechogenicity (total: 1.4% of all subjects examined). It was clearly demonstrated that the urinary excretion of iodine was elevated being above 300 microg Iodine/L in 53% of the schoolchildren examined. Assays for the iodine concentration in the domestic salt samples revealed values between 28.1 and 63.3 mgI/kg of salt. We concluded that the schoolchildren population of the State of S?o Paulo may be under an excessive daily ingestion of iodine. This may induce, if extrapolated to the general population, subclinical hyperthyroidism in the elderly and possibly an increment in the prevalence of chronic autoimmune thyroiditis.     

Croatia has reached iodine sufficiency

This study was performed in 2002, 6 yr after the introduction of a new regulation on salt iodination with 25 mg KI/kg of salt. The aim of the study was to evaluate whether further significant positive results of improved iodine intake could be observed among schoolchildren in Croatia. A total of 927 schoolchildren of both sexes, aged 6-12 yr, were included in the study. In Croatia, with a population of 4,437,460 the research was implemented in four major geographical regions: the Northwestern, Slavonia, Northern Adriatic and Dalmatian regions. Investigations included randomly selected pupils from regional centers and neighboring smaller towns or villages. The results have revealed that thyroid volumes were within the normal range according to the provisional WHO/ICCIDD reference values for sonographic thyroid volume in iodine-replete school-age children, updated in 2001. A significant improvement in medians of urinary iodine excretion was detected in 2002: from 9 microg/dl in 1991 to 14.6 microg/dl in Zagreb, from 4.3 microg/dl in 1995 to 13.1 microg/dl in Split, from 9.4 microg/dl in 1997 to 14.2 microg/dl in Rijeka and from 13.4 microg/dl in 1997 to 14.7 microg/dl in Osijek. An overall median of 14.0 microg/dl of urinary iodine excretion was detected in Croatian schoolchildren. The control of salt at different levels, from production to consumption, including salt produced in all three Croatian salt plants and imported salt, revealed that Croatian salt is adequately iodized. From severe iodine deficiency before the 1950s, through mild-to-moderate iodine deficiency in the 1990s, Croatia has now reached iodine sufficiency.     

Epidemiology of thyroid microcarcinoma found in autopsy series conducted in areas of different iodine intake.

The prevalence of thyroid microcarcinomas found at autopsies is 100-1000 times higher than in clinical cancer. The epidemiological and histological characteristics of thyroid microcarcinomas in consecutive series of autopsies performed in two areas of different iodine intake were investigated. Iodine deficient (ID) area: n = 222 (M = 109, F = 113), median age: 74-76 years, median iodine excretion (MIE) of nursing home residents from this area: 70 microg/g creatinine. Iodine sufficient (IS) area: n = 221 (M = 132, F = 89), median age: 68 years, MIE: 500 microg/g creatinine. When compared to the IS area, the results obtained in the ID area showed a higher thyroid weight (mean 27.75 g +/- 18.43 g vs. 16.5 g +/- 9.6 g, p < 0.0001) and a larger number of goitrous glands (50/222 vs. 5/221, p < 0.0001). Altogether 21 microcarcinomas were found (4.74%) with no iodine intake- or gender-related difference: ID n = 11 (4.95%), M/F = 8/3; IS n = 10 (4.52%), M/F = 6/4. Microcarcinomas seemed to be more prevalent in the 40-59-year age group. All microcarcinomas were of the papillary type. In conclusion, compared to clinical cancer, thyroid microcarcinomas are characterized by a two-scale higher prevalence, are not related to iodine intake, gender or nodularity, are most exclusively of the papillary type.     

Thyroid volume and echostructure in schoolchildren living in an iodine-replete area: relation to age, pubertal stage, and body mass index.

BACKGROUND: Thyroid volume (TV) varies between geographical regions. Thus, population-specific references for TV in regions with long-standing iodine sufficiency may be more accurate than a single international reference. AIM: The aim of the study was to determine TV and assess the prevalence of goiter and thyroid nodules in schoolchildren aged 5-18 years living in an iodine-replete area. METHODS: Ultrasonography was used to assess TV and structure in 440 schoolchildren (200 boys and 240 girls) living in the Athens area. Urinary iodine excretion was also measured. Age, body surface area (BSA), body mass index (BMI), and Tanner stage were recorded. Results: TV was significantly correlated with age in boys (r = 0.779, p < 0.0005) and girls (r = 0.669, p < 0.0005), and with BSA in boys (r = 0.730, p < 0.0005) and girls (r = 0.623, p < 0.0005). TV increased with the progress of puberty in boys (Tanner stage I: 3.42 mL; Tanner stage II-V: 7.35 mL; p < 0.0005) and girls (Tanner stage I: 3.74 mL; Tanner stage II-V: 5.99 mL; p < 0.0005). We used the 97th percentile value as the upper limit and calculated the prevalence of goiter to be 3.2%. There was a weak correlation between TV and BMI standard deviation score only in boys (r = 0.166, p = 0.023). Boys in Tanner stage II-V had larger TV than girls had in the same pubertal stage (7.35 mL vs. 5.99 mL, p = 0.001); such a difference was not observed in Tanner stage I. The median urinary iodine was 307.83 microg I/g creatinine, indicating iodine sufficiency. There was a significant inverse correlation between TV and urinary iodine. In 5.1% of the studied subjects one or more nodules were observed, whereas in 4.1% of cases the nodules were accompanied by hypoechogenicity. CONCLUSIONS: In healthy Greek children living in an iodine-replete area, the main determinants of TV in both boys and girls were age, BSA, and pubertal stage. The prevalence of goiter was 3.2% and that of altered echostructure was 9.2%.     

江苏省6～12岁儿童甲状腺容积正常值

目的：探讨江苏省6－12岁儿童甲状腺容积正常值,方法：在江苏省人群尿碘中位数大于100ug/L碘营养状况正常的地区选择6－12岁儿童用B超作甲状腺容积测量。同时测其身高和体,计算体重表面积,结果：检查6－12岁学龄儿童2100例,甲状腺容积随年龄和体表面积增加而增加,据此提出了江苏省儿童6－12岁各年龄组甲状腺容积正常值范围和按体表面积计算的甲状腺容积正常范围;结论：该正常值范围对江苏省碘缺乏病监测及全国修订儿童甲状腺容积正常值具有一定的参考价值。     

Screening a coastal population in Southern Italy: iodine deficiency and prevalence of goitre, nutritional aspects and cardiovascular risk factors

BACKGROUND AND AIM: To evaluate the prevalence of goitre by means of urinary iodine excretion, palpatory and ultrasonographic thyroid examinations in a heterogeneous population living by the sea. METHODS AND RESULTS: We used a special self-administered questionnaire to evaluate thyroid size, iodine intake, eating habits and cardiovascular risk factors in 600 subjects with a mean age of 45 +/- 17 years: 253 men (42.3%) and 347 women (57.7%). Urinary iodine excretion was low (72.1 +/- 15.7 microg/L; median 71.2) and associated with ultrasonographic evidence of an enlarged thyroid (16%) or structural thyroid abnormalities (30%), thus allowing us to define the Salerno Gulf as a mild-moderate area of endemic goitre. All of the subjects ate a Mediterranean diet, with a mean of two portions of fish/week. The cardiovascular risk factors considered were obesity, cigarette smoking, hypertension, hypercholesterolemia, hypertriglyceridemia and diabetes, the prevalences of which were in line with those reported in other studies of similar age-matched populations. CONCLUSIONS: The moderate intake of fish and the consumption of a Mediterranean diet did not prevent goitre. Iodine deficiency and subsequent goitre endemia are also present at sea level, probably because of a diet based on local products grown on soil with a low iodine content or possible seawater, soil and air environmental pollution that may interfere with the availability of iodine. The assessment of iodine deficiency should therefore involve the entire population and not only subjects living far from the sea.     

Thyroid volumes in schoolchildren of Tehran: comparison with European schoolchildren.

Since the normative values of thyroid volume ultrasonography results from European schoolchildren were endorsed by the World Health Organization (WHO), few studies have addressed the limitation of the recommended references as universal normative values for thyroid volume. Our objective was to describe thyroid volume measured by ultrasonography in Tehranian schoolchildren and compare them with the WHO normative values. Cross-sectional studies were performed in 2016 schoolchildren, aged 6-15 yr, in Tehran 10 yr after distribution of iodized salt. Data were collected on age, sex, weight, height, thyroid size by palpation and ultrasonography, and urinary iodine. Age/sex and body surface area (BSA) upper limits (97th percentile) of thyroid volume were derived. The goiter prevalence was 42% by palpation, 31% grade 1 and 11% grade 2. Median urinary iodine was 21.2 microg/dl. The 97th percentiles were comparable in girls and boys of all ages. Applying the WHO thyroid volume references to the Tehranian children, they did not show any enlarged thyroid based on BSA and on age, even in 11% of children with grade 2 (visible) goiter. In the Tehranian children, the best predictors of thyroid volume were BSA, height and weight. Using linear regression, the 97th percentile of thyroid volume from Tehranian children were lower than the corresponding references from the WHO normative values. The results indicate that a thyroid volume reference based on weight alone would perform as well as the one based on BSA. In addition, until the adoption of a new applicable international reference for thyroid volume, the use of local reference in the screening of children for thyroid enlargement is recommended.     

Residual goitre in the postiodization phase: iodine status, thiocyanate exposure and autoimmunity

OBJECTIVE: This study was done to assess goitre prevalence, thyroid functional status and cause of residual goitre among school children in the postsalt iodization phase in India. DESIGN: A cross-sectional study in which, 14762 school children in the age group of 6-18 years, from different States and Union territories of India, were evaluated for goitre prevalence, urinary iodine and thiocyanate excretion, functional status of the thyroid as well as serological and cytopathological markers for thyroid autoimmunity. MEASUREMENTS: Urinary iodine (wet ashing method), urinary thiocyanate (colourimetric method), serum thyroxine [in-house radioimmunoassay (RIA)], serum TSH (IRMA), antithyroid microsomal and antithyroglobulin antibodies (haemagglutination method) were estimated. Fine-needle aspiration cytology was performed in all goitrous subjects giving consent. RESULTS: The overall goitre prevalence was 23% (27.1% girls; 17.8% boys, P < 0.001). Subjects belonging to poor socio-economic strata had significantly higher goitre prevalence. Median urinary iodine excretion (UIE) in goitrous subjects (2-53 micromol/l) was significantly higher than in controls (2-24 micromol/l; P < 0.001). Levels of UIE observed among goitrous subjects showed no relationship with the presence or absence of thyroid dysfunction or with thyroid antibody status. High titres (> or = 1:1600) of TMA were present more often in goitrous subjects (6.08%) than nongoitrous controls (0.34%; P < 0.001) and in girls (7.3%) than boys (2.35%; P < 0.001). TMA positivity were significantly more among goitrous subjects with thyroid dysfunction than in euthyroid subjects. Significantly higher median urinary thiocyanate (USCN) excretion was observed in goitrous subjects (0.75 mg/dl) compared to controls (0.64 mg/dl; P < 0.001) and goitrous girls compared to goitrous boys. USCN excretion of goitrous subjects and controls showed no relationship with functional or thyroid antibody status in various groups. CONCLUSIONS: Persistent, albeit reduced prevalence of goitre, despite adequate iodine prophylaxis, suggests existence of additional factors in goitrogenesis in India. Thyroid autoimmunity can explain only a part of the goitre prevalence. The role of goitrogens in residual goitre prevalence is brought forth.     

Sex-dependent variations and timing of thyroid growth during puberty

Marked changes in thyroid function occur during puberty as an adaptation to body and sexual development. Characteristics of thyroid growth were investigated in 259 healthy adolescents (110 girls and 149 boys), aged 11--17 yr, in an urban area of Switzerland with sufficient iodine supply. The thyroid volume determined by ultrasonography was correlated with chronological age, body weight, body height, cervical circumference, body mass index, and body surface area (BSA). Iodide concentration was measured in urine. The increase in thyroid volume mainly occurred between 11--15 yr (age at maximum thyroid growth rate, 12.5 yr) and was best correlated with BSA in both genders (girls, r(2) = 0.38; boys, r(2) = 0.49). The BSA-related thyroid growth was almost constant throughout puberty in boys and similar in girls up to menarche, but 14.5% larger in girls after menarche (P < 0.01). Percentiles of thyroid volume were lower than WHO reference values despite low normal urinary iodide concentration (median, 0.75 micromol/L). These findings suggest that physiological thyroid growth during puberty is mainly influenced by growth factors involved in somatic development and further modulated by sex steroid secretion profiles. The thyroid growth spurt coinciding with menarche in girls may contribute to a higher incidence of goiter during mid- to late puberty.     

Local versus WHO/International Council for Control of Iodine Deficiency Disorders-recommended thyroid volume reference in the assessment of iodine deficiency disorders.

OBJECTIVE: Iodine deficiency endemia is defined by the goitre prevalence and the median urinary iodine concentration in a population. Lack of local thyroid volume reference data may bring many health workers to use the European-based WHO/International Council for Control of Iodine Deficiency Disorders (ICCIDD)-recommended reference for the assessment of goitre prevalence in children in different developing countries. The present study was conducted in non-iodine-deficient areas in Malaysia to obtain local children's normative thyroid volume reference data, and to compare their usefulness with those of the WHO/ICCIDD-recommended reference for the assessment of iodine-deficiency disorders (IDD) in Malaysia. DESIGN AND METHODS: Cross-sectional thyroid ultrasonographic data of 7410 school children (4004 boys, 3406 girls), aged 7-10 years, from non-iodine-deficient areas (urban and rural) in Peninsular Malaysia were collected. Age/sex- and body surface area/sex-specific upper limits (97th percentile) of normal thyroid volume were derived. Thyroid ultrasonographic data of similar-age children from schools located in a mildly iodine-deficient area, a severely iodine-deficient area, and a non-iodine-deficient area were also collected; spot urines were obtained from these children for iodine determination. RESULTS: The goitre prevalences obtained using the local reference were consistent with the median urinary iodine concentrations in indicating the severity of IDD in the areas studied. In contrast, the results obtained using the WHO/ICCIDD-recommended reference showed lack of congruency with the median urinary iodine concentrations, and grossly underestimated the problem. The local sex-specific reference values at different ages and body surface areas are not a constant proportion of the WHO/ICCIDD-recommended reference. A further limitation of the WHO/ICCIDD-recommended reference is the lack of normative values for children with small body surface areas (<0.8m2) commonly found in the developing countries. CONCLUSION: The observations favour the use of a local reference in the screening of children for thyroid enlargement.     

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.