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Iodine is an essential micronutrient for human health. Its deficiency causes a number of functional and developmental abnormalities such as goitre. The limestone region of Derbyshire, UK was goitre-endemic until it declined from the 1930s and the reason for this has escaped a conclusive explanation. The present study investigates the cause(s) of goitre in the UK-Peak District area through an assessment of iodine in terms of its environmental mobility, bioavailability, uptake into the food chain and human bioaccessibility. The goitre-endemic limestone area is compared with the background millstone grit area of the UK-Peak District. The findings of this study show that 'total' environmental iodine is not linked to goitre in the limestone area, but the governing factors include iodine mobility, bioavailability and bioaccessibility. Compared with the millstone grit area, higher soil pH and calcium content of the limestone area restrict iodine mobility in this area, also soil organic carbon in the limestone area is influential in binding the iodine to the soil. Higher calcium content in the limestone area is an important factor in terms of strongly fixing the iodine to the soil. Higher iodine bioaccessibility in the millstone grit than the limestone area suggests that its oral bioaccessibility is restricted in the limestone area. Iodine taken up by plant roots is transported freely into the aerial plant parts in the millstone grit area unlike the limestone area, thus providing higher iodine into the human food chain in the millstone grit area through grazing animals unlike the goitre-prevalent limestone area.

In developed countries, the use of iodised salt represents the best prophylaxis of endemic goitre in areas exposed to iodine deficiency. In the present study we re-evaluated goitre prevalence and iodine intake 10 years after the introduction of iodised salt in an area of goitre endemia in north-eastern Sicily (Italy), and we compared these results with those obtained in previous surveys. Three centres with known moderate goitre endemia (Bronte, Nicosia, and Gagliano) and three other smaller ones with severe goitre endemia (Sperlinga, Villadoro, and Maniace) were studied. We surveyed 697 schoolchildren. Goitre prevalence was assessed by thyroid palpation and by a thyroid ultrasound scan. Iodine urinary excretion was also measured. Iodised salt consumption was 44% of total salt consumption. Goitre prevalence assessed by thyroid palpation was significantly decreased in all towns studied compared to previous surveys. However, the persistence of a mild goitre endemia was observed in some small rural centres (5.8% in Sperlinga/Villadoro, and 11.4% in Maniace). Goitre prevalence evaluated by thyroid ultrasound scan was greater than 5% in all centres of the endemic area and was always greater than that assessed by thyroid palpation. Iodine urinary excretion was above 100 microg/l in all localities studied. In conclusion, our studies indicate a progressive reduction in goitre prevalence over a period of about 30 years in schoolchildren in a well-characterised endemic area in northeastern Sicily. The decrease in goitre prevalence was associated with a significant increase in urinary iodine excretion. However, it may be speculated that iodine deficiency is the pre-eminent, but not the exclusive cause of goitre endemia in this area.

Background: Eleven years after the initiation of universal salt iodization program in Iran, the prevalence of goiter is still high in some areas., Aim: To investigate the role of thyroid autoimmunity in the etiology of residual goiter in schoolchildren of Isfahan, Iran., Material and Methods: In a cross-sectional study, 2331 schoolchildren were selected by multi-stage random cluster sampling. Thyroid size was estimated in each child by inspection and palpation. Urinary iodine concentration (UIC), serum anti-thyroperoxidase antibody (anti-TPO Ab), and anti-thyroglobulin antibody (Anti-Tg Ab) were measured., Results: Overall, 32.9% of children had goiter. The median UIC was 1955.5 microg/dl. There was significant difference in prevalence of positive anti-TPO Ab in goitrous (grade 2) and non-goitrous children (9.7 vs 3.7%, p= 0.02). Goitrous children had higher prevalence of positive anti-Tg Ab than non-goitrous ones (15.1 vs 3.1%, p<0.001)., Conclusions: According to the present study, goiter is still a public health problem in this region. This study suggests that thyroid autoimmunity is among the contributors of goiter persistence after elimination of iodine deficiency in Isfahan.

Objectives: To evaluate the current nationwide iodine status in Turkey by determining urinary iodine concentrations (UIC) and household salt iodine content. A follow- up monitoring study was also conducted in 30 urban areas., Methods: A school-based survey was conducted in 2007 by using multistage 'proportionate to population size' (PPS) cluster sampling method. The study population was composed of 900 school-age children (SAC) from different urban, suburban, and rural areas. UIC and iodine content of the table salt used at home were analyzed., Results: Median UIC was 107 microg/l (147 in urban, 42 in suburban and rural areas, p<0.001). There were severe iodine deficiency (ID) in 7.2%, moderate and mild ID in 20.6% and 19.3%, of the SAC, respectively. UIC was sufficient (>100 microg/l) in 50% of the study population, whereas it was excessive (>300 microg/l) in 10.5% of them. Of the 900 salt samples, 662 (73.5%) were iodized and 508 samples (56.5%) contained adequately iodized salt (iodine content >15 ppm). UIC of the study population and salt iodine levels correlated well (r=0.42, p<0.001)., Conclusions: Moderate to severe ID still exists in 27.8% of the Turkish population, which is much better compared to 1997 and 2002 surveys (i.e. 58%, 38.9%, respectively). The follow-up monitoring study (in 2007) demonstrated that ID has been eliminated in 20 of 30 cities surveyed, and median UIC was 130 microg/l. ID has been eliminated in most of the urban population, however, it is still an important problem in rural areas and in particular geographical regions, which should be the target of future programs.

Objective: Most of the Polish territory has been classified as an iodine-deficient and endemic goiter area according to the International Council for Control of Iodine Deficiency (ICCIDD) criteria. In 1997 the obligatory model of iodine prophylaxis was implemented. Our investigations were aimed at the effectiveness of iodine prophylaxis in Poland., Methods: We assessed urinary iodine excretion and goiter prevalence in 5663 children aged 6-12 yr. The population of children from the same 27 schools was investigated from 1992 to 1994 (1406 girls and 1244 boys) and from 1999 to 2005 (1563 girls and 1450 boys) using identical laboratory and ultrasound methods., Results: We found significant increase in iodine urinary concentration (median 52 microg/l vs 93 microg/l, p<0.001) with accompanying drop in goiter prevalence (29.6% vs 5.2%, p<0.001) after implementation of iodine prophylaxis. Iodine excretion distribution changed significantly after 1997 with an increase in the percentage of children with iodine urinary concentration above 100 microg/l from 10.8% to 45.4%, respectively. A significantly higher iodine urinary concentration was observed in lowlands compared to uplands both before and after implementation of iodine prophylaxis (median, 50 microg/l vs 57 microg/l and 86 microg/l vs 114 microg/l, respectively, p<0.001). The goiter prevalence did not differ between girls and boys from 1992 to 1994 (28.8% vs 30.5%, p=0.35) and 1999 to 2005 (5.5% vs 4.9%, p=0.45)., Conclusions: Implementation of the new model of iodine prophylaxis in Poland in 1997 has led to significant increase in iodine urinary concentration and decrease in goiter prevalence among Polish schoolchildren. In the youngest group of children (6-8 yr olds), prevalence of goiter decreased to 3.2%--i.e. below endemic levels.

Iodine is an essential trace element which is found in too low quantities in the soil in Germany. The resulting iodine deficiency in human beings is countered by iodine prophylaxis, essentially consisting of iodised table salt and the iodisation of agricultural animal feed. In iodine monitoring during the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), the thyroid volumes of all children and adolescents from six years of age were determined using sonography. To assess iodine intake among the population, iodine excretion in the urine was also measured. The median ioduria value was 117 microg/l, putting it at the lower end of the scale of 100-200 microg/l recommended by the World Health Organisation. It can be concluded from these results that the iodine prophylaxis has been successful and that iodine intake has improved compared with the past. In accordance with the WHO recommendations there is no iodine deficiency in Germany any more; however, at the same time the population's iodine intake is at a relatively low level. The aim is at least to keep up what has been achieved, meaning that measures to improve iodine intake must not be allowed to slacken.

Goiter rate, serum TSH, antithyroperoxidase (TPOAb), antithyroglobulin (TgAb) antibodies, and urinary iodine concentration (UIC) were evaluated 10-11 yr prior (1983-1984) and 5-6 yr after (1999-2000) national salt iodization in Iran. Pre- and post-iodization groups consisted of 465 and 1426 adults aged > or =20 yr, respectively, selected by random cluster sampling in Tehran province. Total, grade 1 and grade 2 goiter rates were 65.2, 53.1, and 12.1% in 1983-1984 vs 25.2, 15.5, and 9.7% in 1999-2000 (p<0.0001). Median serum TSH was 1.5 mIU/l in 1983-1984 vs 0.8 mIU/l in 1999-2000 (p<0.0001). Median TSH also decreased in 20-29, 30-39, 40-49, 50-59, and > or =60- yr-adults in 1983-1984 vs 1999-2000 (p<0.0001). In 1983-1984, positive TPOAb and positive TgAb were detected in 3.2 and 4%, respectively, using agglutination test. Corresponding values were 12.5 and 16.8% using immunoenzymometric assay in 1999-2000. Overt and subclinical hypothyroidism was present in 0 and 32.8/1000 in 1983-1984 vs 3.5 and 21.7/1000 in 1999-2000, respectively. Overt and subclinical hyperthyroidism was detected in 4.4 and 4.4/1000 in 1983-1984 vs 0.7 and 5.6/1000 in 1999-2000, respectively. Subclinical hypothyroidism in males was significantly more frequent in 1983-1984 vs 1999-2000 (odds ratio 5.02, 95% confidence interval 1.72-14.68; p=0.004). Salt iodization resulted in adequate UIC, decrease in serum TSH and subclinical hypothyroidism in males, and an increase in thyroid autoantibodies without significant change in thyroid abnormalities. Benefits of iodine supplementation far outweigh its hazards in Tehranian adults.

In Germany, iodine deficiency and its consequences is still a problem, although it is of less importance than it was twenty years ago. In accordance with the WHO definition, Germany still belongs among those countries with mild iodine deficiency and too low an intake of iodine. As a result groups at particular risk, such as pregnant and nursing women, must still receive iodine supplementation, since, in the absence of supplemental iodine,the amount of iodine in the mother's milk continues to be below average throughout Germany. Both in private households and in the food industry, the aim is to increase the use of iodized salt to more than go%. This entails no risk of an iodine overdose. The current average daily uptake of iodine of approximately 120 micrograms is responsible neither for the development or progression of an autoimmune disease nor a functional disorder of the thyroid gland.

Iodine deficiency is still an important health care problem in the world. In Italy, as in most European countries, it is responsible for the development of mild to moderate endemic goiter. In 1995 we conducted a goiter survey in the Gubbio township, an area of Umbria region in Italy, close to the Appenine mountain chain. This study demonstrated a high prevalence of goiter in the middle schoolchildren population, indicating the presence of moderate endemic goiter. Soon after, a goiter prevention campaign aimed at implementing the consumption of iodinated salt was started. In 2001, a second survey was conducted in the middle schoolchildren (age 11-14 yr old) of Gubbio and neighbour townships. Eight hundred thirteen subjects were studied. Data obtained in 240 age-matched children, studied in the same area in 1995, were used for comparison to monitor changes 5 yr after the beginning of iodine prophylaxis. Thyroid volume was measured by ultrasonography. Gland volume was expressed in ml. A large population living in a iodine-sufficient area, previously reported by others, was used as control. Urinary iodine excretion was measured randomly in 20% of the children. The overall prevalence of goiter decreased between 1995 and 2001 from 29 to 8%. Goiter odds ratio (OR), corrected for age, was 4.0 (95% CI 2.8-5.9) for 1995 compared to 2001 (p<0.000). Mean thyroid volume in the matched populations was 7.6+/-2.5 ml in 1995 and 5.7+/-2.1 ml in 2001. Median iodine urinary excretion increased from 72.6 to 93.5 mug/l, at the limit of statistical significance. Living in a rural area, no consumption of iodized salt and familiarity for goiter represented independent risk factors for goiter development. This study was the first conducted in Umbria region and confirmed that an implementation campaign for iodized salt consumption is a simple and useful instrument to prevent endemic goiter and related diseases. A new survey to evaluate goiter prevalence in the same area 10 yr after the beginning of iodine prophylaxis is already planned.

Objective: The determination of (a) iodine deficiency, and (b) the relation between the iodized salt consumption in the Isparta province of Turkey., Methods: Five hundred students between 6-11 yr of age were evaluated. With a questionnaire, the subjects were asked whether they were using iodine-containing salt or not. After their body weight and height were measured, thyroid glands were examined with palpation, thyroid volumes were determined with ultrasonography (USG), and urinary iodine concentration was analyzed., Results: The median urinary iodine concentration (UIC) of children was 7.00 microg/dl. This value reveals that Isparta is a region with mild iodine deficiency. The total goiter prevalence was 30.4% with palpation and 26% with USG. The goiter prevalence by ultrasonography was 14.2% for the urban and 36.2% for the rural areas. This difference was statistically significant (p<0.05). The rate of total iodized salt consumption was 68%, which was not a satisfactory level. The consumption of iodized salt in the urban areas was significantly higher than that in rural areas (74 vs 62%, p<0.05). The median UIC value was 10.00 microg/dl in urban areas compared to 5.00 microg/dl in rural areas., Conclusions: Our results indicate that although Isparta is a region with mild iodine deficiency, goiter prevalence remains a serious problem.

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.

An optimal supply of iodine--150-200 microg/day--has not yet been secured in all regions and in all phases of life. The appreciable diminishment in thyroid gland mass in children and adolescents is, however, indicative of an improvement in this situation. In elderly persons, however, prophylactic measures do not result in struma or nodule regression. Nodules are found in some 40% of women and 28% of men older than 45. Medical treatment of nodular goiter is aimed at achieving a reduction in size or preservation of the status quo. Depending on the size of the goiter, iodine-deficiency goiter is treated with iodine or a combination of iodine and levothyroxine. In view of the pathogenesis and the marginal alimentary lack that still persists, there are no adequate arguments for L-thyroxine monotherapy of uncomplicated iodine-deficiency goiter.

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.

In order to reduce the still substantial iodine deficiency in the Austrian population, compulsory iodisation of salt was increased in 1990 from 10 mg potassium iodide/kg salt to 20 mg potassium iodide/kg. In this investigation we evaluated the adequacy of iodine supply in Vienna and the Waldviertel, a rural region northwest of Vienna. Daily iodine excretion (which reflects daily iodine intake) was investigated in 92 persons from the Waldviertel (all without thyroid gland pathology) and 110 persons from Vienna (54 with unremarkable thyroid glands, 56 with endemic goiter). Daily iodine excretion was higher in persons from the Waldviertel (161 +/- 90.7 micrograms/24 h, p < 0.05) than in those from Vienna (with healthy thyroid glands 126.4 +/- 42.9 micrograms/24 h and with goiter 117.2 +/- 60.5 micrograms/24 h, resp.). In both populations iodine supply as defined by the WHO (excretion of > 150 ug iodine/day) was inadequate. The recommended level was not achieved in 50% of the persons from the Waldviertel region and in 75% of persons from Vienna (healthy thyroid glands 76%, goiter: 75%). Iodine deficiency (intake < 100 micrograms/24 h) was present in 42% persons from the Waldviertel and in 31% and 24% persons, respectively, from Vienna with unremarkable thyroid glands and goiter. We conclude that although the iodine content of salt was increased, an iodine deficiency was present in a considerable portion of the population of an industrialized country (approximately 40% of persons from a rural region and 30% from the city of Vienna).

In the beginning of the nineties, 40 years after introduction of iodine prophylaxis in Croatia, on a basis of a frequent reports coming from general practitioners about the presence of a rather high prevalence of goiter among schoolchildren, a nationwide study was initiated with the aim to determine the real prevalence of goiter in the country. A total of 2856 schoolchildren of both sexes, aged 7-15 years, were included into the study. Investigations were designed in a way to cover most of geographical regions in Croatia and subjects were randomly selected. The prevalence of goiter in schoolchildren was assessed by palpation and in part by ultrasonography of the neck. At the same time urinary iodine excretion was measured and iodine content in salt samples was determined. The results have revealed the persistence of mild endemic goiter in inland parts of Croatia with the prevalence of 6-29% in the age group 7-11 years and those of 10-43% among the age group 12-15 years. The overall goiter prevalence in schoolchildren in Croatia fluctuates from 8% to 35%. Such prevalence, most probably due to less than optimum iodine intake, is unlikely to change until iodine content of the salt is increased from its present level of 10 mg of Kl per kg of salt.

In order to reduce the prevalence of goiter in a village of Mali liable to iodine deficiency, an iodized product (Lipiodol Ultra Fluide) was orally administered to their inhabitants. Taking into account a series of demographic variables and goiter types, a protocol was conducted using Lipiodol at three different dosage levels. Six months after the treatment, the hormone levels regained normal values, whereas only the smallest dose reduces the volume of goiters significantly.

We evaluated the prevalence of antithyroid peroxidase antibodies (anti-TP0 Ab) in 402 patients with thyroid disease and 30 healthy controls by a commercial radioimmunoassay (RIA) and compared the results with the passive hemagglutination (HA) method. The patients in the study had autoimmune thyroid disorders (AITD) such as Graves' disease and Hashimoto's disease or had nonautoimmune thyroid diseases (NAITD) such as thyroid cancer, congenital goiter, endemic goiter, and nodular goiter. Subjects were recruited from a population with a mild iodine deficiency (Sao Paulo, Brazil). The effect of specific therapy (for either thyrotoxicosis or chronic thyroiditis) on the circulating anti-TPO levels was also investigated. Positive anti-TPO Ab was detected in 89.9% of the patients with AITD as compared with a prevalence of positive tests of only 4.8% in patients with NAITD. Positive microsomal antibody (M Ab) was found in 68.4% of the patients with AITD and in 6.4% of the patients with NAITD. A positive and significant correlation was obtained between M Ab and anti-TPO Ab. A positive anti-TPO test with negative anti-M was found in 14.1% of the patients with AITD but in only 4.3% of the patients with NAITD and normal controls. These results suggest that anti-TPO Ab by RIA is more sensitive and specific than M Ab by HA. In patients with AITD, anti-TPO Ab levels usually decreased after treatment, suggesting that this parameter could be used in the follow-up of these thyroid disorders.

An endemic goiter study was carried out in a vast territory of the Calabria region, including the provinces of Catanzaro and Cosenza. About 50% of 7231 school-children, aged between 6 and 12 years, examined in 34 villages, presented a thyroid enlargement. The high prevalence of goiter seems to be related to a moderate iodine deficiency intake indicated by a mild urinary iodine excretion (lower than 100 micrograms/g creatinine). In a few villages, in which a two year voluntary iodine prophylaxis was carried out, an increase in the urinary iodine excretion with a decreased goiter prevalence was observed. A slight increase in TT3, FT3 and TSH in one endemic area studied, compared to the control area, was also observed. These data suggest that an effective program of iodoprophylaxis is fundamental in this region as well.

Endemic goiter in Morocco is localized in the Rif and Atlas mountains. In this study, performed in the Skoura-Toundoute areas (high Atlas), we demonstrate that iodine deficiency is the main factor involved in the development of endemic goiter. However it may not constitute the only etiological factor. The median urinary iodine excretion, measured on untimed samples, was low both in goitrous patients, m = 18 micrograms/l (n = 109) and in non goitrous subjects, m = 24 micrograms/l (n = 47). The value found in a nonendemic region (Casablanca) was much higher m = 117 micrograms/l (n = 67). Another approach to evaluate iodine intake per day was the analysis of iodine content of some samples of cereals (barley, wheat and corn), drinking water, sea and rock salt, cow and breast milk. Iodine content is low, specially in the endemic area: barley = 90 micrograms/kg (n = 1); wheat = 227 micrograms/kg (n = 1); corn = 91 micrograms/kg (n = 1); water = 0.92 to 1.30 micrograms/l (n = 3); cow milk = 6 to 33 micrograms/l (n = 10) breast milk = 10 to 55 micrograms/l (n = 14); rock salt = 420 to 660 micrograms/kg (n = 8); sea salt = 90 to 160 micrograms/kg (n = 4). Sodium chloride intake per day, estimated by the measurement of sodium and chloride urinary excretion, is normal both in the Skoura-Toundoute areas (10.7 g and 9.8 g for goitrous and nongoitrous subjects, respectively) and in Casablanca (10.9 g for control persons). Altogether the results demonstrate the importance of introducing the practice of iodinated salt in the prophylaxis of endemic goiter in this area.

During a multicentric pilot screening program for congenital hypothyroidism a comparison between the results obtained from Urbino, an area characterized by low iodine supply and endemic goiter, and Rome, a non-endemic area, has been made. The evaluation of neonatal urinary iodine excretion in the two areas showed significantly lower iodine urinary excretion levels in Urbino than in Rome. A shift of TSH at screening toward higher values as well as a higher percentage of recall in Urbino area than in Rome was observed. This finding, which well correlates with a low environmental iodine supply, emphasizes the importance of screening for congenital hypothyroidism as a suitable index of the presence and action of goitrogenic factors in the environment.

A study of endemic goitre was carried out in the western part of the province of Foggia (Daunia's pre-Appennines). About 50% of a total of 2719 children aged 6-15 years examined in the agricultural and hill towns of Accadia, Bovino, Candela, Deliceto and Sant'Agata di Puglia (500 to 800 m above sea level), presented a thyroid enlargement (usually of Grade 1). Urinary creatinine values were normal, while urinary iodine was low: 37.7 +/- 28.39 mug/g creatinine (mean +/- SD for 319 subjects). Serum levels of thyroid hormones were normal: T4 = 7.89 +/- 2.61 mug/dl; T3 = 114.72 +/- 40 ng/dl; T3 (T4 X 100) = 0.166 +/- 0.09. Subjects with Grade 2 thyroid enlargement had significant lower urinary iodine and serum T4, and higher T3 and T3/T4 ratio than children without goitre (Grade 0). Serum thyrotropin was rather high (3.79 +/- 4.17 muU/ml), but bore no straight relation to the thyroid size; in subjects with Grade 2 thyroids there was an inverse relationship between plasma T4 and TSH levels. Drinking water iodine was generally low (2-3 mug/l), though some richer sources (18, 38, 66 mug/l) were noted. Iodine contents of locally produced foodstuffs were below those found in food on Turin markets.

After 17 years the efficiency of iodine prophylaxis of endemic goiter (1 : 100000) in Austria was checked by control field studies in 3 Tyrolean towns n Austria. The data obtained there were compared with those of 123 school age children from the iodine deficient endemic goiter area of the province of Bolzano (Italy). The results show a reduction in goiter incidence from 50 to 35% in the total population in Austria, where goiter incidence in schoolchildren dropped from 45.9% to 12%. Urinary iodine/g creatinine was 65 micrograms in Austria, the 24 hr radioiodine uptake with 41.8% was normal. In comparison the ethnologically and geographically similar endemic goiter zone in the province of Bolzano showed a goiter incidence in schoolchildren of up to 46%, while urinary iodine/g creatinine was 35.9 micrograms and radioiodine uptake after 24 hr about 50%. Extensive studies of peripheral hormone parameters (T4, TBG, T3, TSH, rT3, FT3, FT4) revealed a significantly higher rT3 concentration of 24.7 ng/dl in Austria compared with a value of only 19.8 ng/dl in the province of Bolzano. These facts suggest an increased conversion of T4 to real T3 in iodine deficiency, which might contribute to the adaptation of the organism to this condition. No statement, however, can be presented regarding the regulation of this phenomenon. Even as endemic goiter is decreasing in Austria, an increase of salt iodization to 1 : 50000 according to the swiss procedure might eliminate definitely endemic goiter in Austria.

The goitrogenic role of autoimmune phenomena in endemic goiter is still uncertain. Scanty and discrepant results have been reported in different areas of the world. This prompted us to evaluate the prevalence of circulating thyroid antibodies in an area of North-Western Tuscany during a survey for endemic goiter. The survey was carried out according to the P.A.H.O. criteria in a stable community. In all schoolchildren (n = 142, age range 7-15 yr) and in most of their parents (n = 159), thyroid size was evaluated and urine was collected for iodine determination. Blood was drawn for determination of circulating thyroid microsomal (MAb) and thyroglobulin antibodies (TgAb), TT3, TT4 and TSH. Prevalence of goiter in schoolchildren was 77.9% and 94.8% in their parents. Mean (+/- SD) urinary iodine excretion was 55.0 +/- 2.1 micrograms/24 h. The overall frequency of TgAb and MAb in the adult population was 14.4%, statistically higher than that of control subjects matched for sex and age. The frequency in schoolchildren was 4.3%. The presence of goiter in children was unrelated to the presence of thyroid antibodies in parents, whether goitrous or nongoitrous. A higher prevalence of goiter was found in children with goitrous parents as compared to children with nongoitrous parents (p less than 0.005). In conclusion, the frequency of thyroid autoantibodies in the adult population of the endemic area studied was increased, but showed no relation with the presence of goiter. The prevalence of goiter in children was associated with the presence of goiter but not of thyroid autoantibodies in parents. These data suggest that autoimmune phenomena are of limited importance in the development of endemic goiter.

The prevalence of goiter among schoolchildren and the daily urinary iodine excretion in the general population were evaluated in 4 municipalities in the endemic goiter area in Northeastern Sicily in two different surveys. The first, carried out in 1977-1978, covered 2,493 (91%) schoolchildren; the second, in 1987-1988, covered 2,167 (92%) schoolchildren. A dramatic decrease in goiter prevalence was apparent in each community as follows: in Castell'Umberto (3,904 inhabitants, altitude 641/750 m above sea level) goiter prevalence (G) decreased from 79.7% to 44.2% with a percent reduction (%r) of 44.5 and an increase in 24-h urinary iodine excretion (UIE) from 22.3 +/- 16.4 micrograms/24 h (n = 30) to 48.7 +/- 43.4 (n = 50). A similar trend was apparent in Tortorici (10,194 inhabitants, 475/700 m) where G decreased from 62.2 to 26.5% (% r 57.4) with a UIE increase from 28.4 +/- 29.6 (n = 35) to 47.6 +/- 59.3 (n = 40); in Sinagra (3,387 inhabitants, 300 m) where G decreased from 61.6 to 32.7% (% r 46.9) and UIE increased from 26.0 +/- 21.1 (n = 25) to 66.6 +/- 69.6 (n = 102) and in Sant'Angelo di Brolo (5,732 inhabitants, 380 m) where G decreased from 48.7 to 27.5% (% r 43.5) and UIE increased from 26.3 +/- 16.7 (n = 30) to 47.7 +/- 73.8 (n = 34). These events are clearly related and certainly dependent on the changed alimentary habits in the area due to the improved distribution of frozen food and industrially prepared dairy products, eventually enriched by iodine.(ABSTRACT TRUNCATED AT 250 WORDS)