Goiter prevalence and urinary excretion of iodine in a sample of school age children in the city of Rome

The aim of the study was the assessment of the urinary iodine excretion and the evaluation of thyroid volume compared with clinical examination in 1040 schoolchildren (6-14 years old), living in Rome. Mean urinary iodine excretion was 98.52 +/- 49.81 micrograms/l (median 92 micrograms/l). Thyroid enlargement, as assessed by palpation, was found to be grade 1A in 35.4% of the children, grade 1B in 9.6% and grade 2 in 0.2%. Thyroid volume, determined by ultrasound, increased with age, was significantly correlated with body surface area and was significantly higher in females, as compared to males, in the 11 and 12 years old group. Eleven children (1.9%) were negative at palpation (grade 0) but showed thyroid enlargement by ultrasound. The prevalence of goiter determined by ultrasound resulted to be 4.7%.     

Epidemiologic investigation on the prevalence of goiter and urinary excretion of iodine in the school population of the province of Reggio Emilia

The prevalence of goiter was evaluated in a sample from the schoolchildren population of Reggio Emilia district. 1020 children underwent physical examination of thyroid gland and thyroid ultrasonography for determination of thyroid volume. Urinary iodine excretion (UIE) was measured in 837/1020 (82.1%). Iodine content was measured in water samples collected from 65 wells and 12 springs all around the district. The prevalence of goiter according to thyroid gland palpation was 26.2%. Thyroid volume was 4.74 +/- 1.87 ml, and the median UIE value 85 micrograms/l. According to the UIE classes as defined by WHO, 57.8% of all subjects showed a UIE less than 100 micrograms/l. In 57 out of 65 wells and in all the 12 springs examined, iodine was completely absent. In the remaining 8 wells, only iodine traces were found. Based on the results of physical examination of the thyroid gland, Reggio Emilia district should be regarded as an endemic goiter area. Nevertheless, thyroid volume measurement by ultrasound indicates that goiter prevalence may be markedly overestimated by palpation. The high prevalence of subjects featuring an increased thyroid volume, the low median UIE value and the poor iodine content in the local reservoirs of drinkable water suggest the opportunity for iodine prophylaxis in the Reggio Emilia district.     

Prevalence of goiter and urine iodine in a school population in an area of the Bolognese Apennines

We evaluated goiter prevalence and urinary iodine excretion (UIE) in schoolchildren living in three villages of the Appennines in the Bologna district-Castel d'Aiano (CA), Gaggio Montano (GM) and Pietracolora (PC). 175 age-matched schoolchildren living in the urban area of Bologna were considered as control group. In the control area the presence of goiter was documented in 11 out of 175 subjects (6.3%). In the mountain area the presence of goiter was documented in 42 out of 233 subjects (18%) (p < 0.0001 vs control area). In the urban control area the UIE was 159 micrograms/l (median; range 19-298). In the mountain area the UIE was 119 micrograms/l (median; range 10-286) (p < 0.001 vs control area). We observed the highest prevalence of goiter and UIE levels < 100 micrograms/l only in the village of PC, which is still characterized by geographical isolation and rural economy.     

Experience with iodine prophylaxis in the province of Bolzano

Since 1981 in the province of Bolzano a "free-choice" iodine prophylaxis with iodinated dietary salt has been implemented. An epidemiological survey carried out in 1982 in 3109 schoolchildren living in this region showed an incidence of endemic goiter grade 1B-3 (WHO classification) of 23.6 +/- 14.0% and an urinary iodine excretion of 10.2 +/- 8.0 micrograms/l (colorimetric analysis) compared to the values of 39.6 +/- 17.7 micrograms/l found in a similar population of schoolchildren living in a non goitrous urban area in Northern Italy (Padua). This program of iodine prophylaxis was advertised through the local mass media. A further epidemiological survey, performed in the whole province in the year 1990, involving 1046 schoolchildren, randomly selected, showed an average goiter incidence of 1.6 +/- 1.3% and a urinary iodine excretion of 137.1 +/- 104.4 micrograms/l (ICP-MS analysis) in comparison to the values of 182.6 +/- 131.7 micrograms/l seen in the schoolchildren of the town of Padua. During the period of iodine prophylaxis the content of iodine in the commercially available iodinated dietary salt was also estimated. In 1990 the average content was 31.0 mg/kg and in 1997 was 27.1 mg/kg. These data therefore confirm the usefulness of iodinated salt in the prophylaxis of endemic goiter.     

European project of structural funds: eradication of endemic goiter and iodine deficiency disorders in Southern Italy

Iodine deficiency disorders and endemic goiter are still present in the population of Southern Italy, where the use of iodized salt is not widely diffused because of a lack of information and health education on this problem. The aim of this project financed by the "structural funds" (objective 1) of the European Union, is to eradicate endemic goiter and iodine deficiency in the population of Southern Italy. The project comprises various subsequent steps. Initially, the grade of iodine deficiency (measuring urinary iodine excretion) and the prevalence of endemic goiter (measuring thyroid volume by echography) will be evaluated in the whole schoolchildren population aged 12-14. In addition, a widespread promotional campaign on the mass media (newspaper, TV, etc.) will be performed in order to implement the use of iodized salt. Subsequently, the effect of this campaign to promote the use of iodized salt will be verified evaluating the increase of urinary iodine excretion and the decrease of enlarged thyroid volumes in the schoolchildren population.     

Efficacy and safety of iodine prophylaxis

Iodine deficiency and iodine deficiency disorders (IDD) are still present in developing countries as well as in some European areas. It is well known that iodine deficiency correction prevents endemic goiter and other IDD. Iodized oil has been shown to reduce goiter prevalence and cretinism in African countries. In countries where iodine prophylaxis is performed since many years (USA, Switzerland, Scandinavian countries) IDD are dramatically reduced. One example of the efficacy of iodine prophylaxis through iodized salt was reported in a Tuscan village were urinary iodine excretion increased from 47 micrograms/l in 1981 to 130 micrograms/l in 1991. Goiter prevalence in schoolchildren dropped from 60% in 1981 to 8.1% in 1991. In the same children neuropsychological performances were evaluated showing a reduction of motor response to perceptive stimuli assessed by measurement of reaction times in children born before the beginning of iodine prophylaxis. Iodine prophylaxis has no side effects, although a transitory increase of hyperthyroidism has been reported in the past and recently in African countries. A reevaluation by the experts of the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) has pointed out that this phenomenon is not relevant with respect to the efficacy of iodine prophylaxis. In conclusion, universal iodine prophylaxis prevents endemic goiter and other IDD, without side effects.     

Current status of iodine deficiency in Mongolia in 1998-1999

In 1992, the Mongolian government conducted a nationwide palpation study of the thyroid glands, and the study showed an overall goiter rate of 30%. As a result of this, the Mongolian Government launched its Iodine Deficiency Disorders (IDD) Elimination Programme in 1996 and its primary strategy was salt iodization. In 1998 and 1999, we carried out programme monitoring studies in 11 provinces. The results showed: among schoolchildren, a goiter rate was 22.8% (n = 6,535), median values of urinary iodine excretion ranged from 11 micrograms/l to 256 micrograms/l (n = 1,930), and usage rates of iodized salt (> 20 PPM iodine content) in their households ranged from 3% to 82%. We concluded that severe iodine deficiency in 1992 was improved from moderate to mild severity a few years later by salt iodization. However, stronger official commitments and community participation are needed to improve the programme so that iodized salt will be made more widely available.     

Benefits and risks from the national strategy for improvement of iodine nutrition: A community-based epidemiologic survey in Chinese schoolchildren

ObjectiveMild to severe iodine deficiency has been documented in China since 1960. To eliminate this persisting iodine deficiency, legislation on universal salt iodization was introduced in 1995 as a long-term public health intervention strategy. We examined the urinary iodine excretion and the iodine content of drinking water and salt samples to assess the benefits and risks of this national strategy.MethodsWe examined the urinary iodine excretion of 1594 schoolchildren 8 to 10 y old from the 16 counties of China. The iodine content of 1097 drinking water and 4501 table salt samples also was assessed in these counties. The study was conducted from April 2009 through October 2010. Urinary iodine excretion and iodine levels in drinking water and table salt samples were measured based on the Sandell–Kolthoff reaction. Data were interpreted according to World Health Organization criteria.ResultsThe median urinary iodine levels of the schoolchildren were 198.2, 277.2, 336.2, and 494.8 μg/L in areas with iodine levels lower than 10, 10 to 150, 150 to 300, and higher than 300 μg/L in the drinking water, respectively. The mean iodine level in the table salt specimens was 30.4 mg/kg, the coverage rate was 98.6%, and the qualified rate was 96.7%. The goiter prevalence was 8.0% in the areas with an iodine level higher than 150 μg/L in the drinking water.ConclusionIn each area, the median urinary iodine of schoolchildren was nearly or above 200 μg/L, which confirmed the effectiveness of the iodization strategy. However, in areas with an iodine content higher than 150 μg/L in the drinking water, the schoolchildren had more than adequate or excessive iodine intake, which was associated with the prevalence of goiter. Therefore, it is important to adjust the strategy of universal salt iodization control in China.     

Monitoring iodine following consumption of iodized salt in Tehrani inhabitants

As the production, distribution and consumption of iodized salt has increased in recent years, this study was carried out to assess iodine status in Tehran in 1996. 1146 families comprising 5140 subjects in the twenty districts of Tehran city from all age groups were randomly selected. Thyroid size was examined by palpation and graded according to the WHO classification. In 163 families selected randomly, thyroid size was determined by ultrasonography and urinary iodine was measured by digestion method. Serum T4, T3 and TSH (IRMA) concentrations were also assayed by kits. Percentage of grades 1 & 2 goiter were 44 & 44% in females and 49 & 33% in males respectively. Median urinary iodine was 17.5 micrograms/dl. Mean serum T4, T3 and TSH were 8.41 +/- 1.4 micrograms/dl, 170 +/- 37 ng/dl and 1.4 +/- 0.8 mu/ml, respectively. In 118 children aged 6-10 years median urinary iodine was 17.5 micrograms/dl. Thyroid volume in children was 4.3 +/- 1.9 ml. No correlation was established between the thyroid volume and goiter grade. This study points to the adequacy of iodine intake in the majority of families residing in Tehran.     

Goiter prevalence,urinary iodine excretion,thyroid function and anti-thyroid function and anti-thyroid antibodies after 12 years of salt iodization in Shahriar,Iran

OBJECTIVE: In a previous study in 1983, goiter was found to be endemic in Shahriar, Iran. Iodized salt has been distributed in the region for the past 12 years, and the present study was performed to examine the effect of iodide supplementation on indicators of iodine deficiency (IDD) and thyroid antibodies. DESIGN & METHODS: A total of 3164 people, 58% women and 42% men, were selected by random sampling from the Shahriar area. Goiter was staged according to World Health Organization guidelines. Urinary iodine was measured by a digestion method, and thyroid hormone measurements were done by radioimmunoassay. The results were compared with those of 1983. RESULTS: Goiter prevalence before and after iodine supplementation was 50 and 40% in men, 70 and 51% in women, and 60 and 47% in the whole community, respectively (p < 0.001). A decrease in the prevalence of goiter was observed especially in younger individuals. The mean urinary iodine excretion was 7.6 and 18.5 micrograms/dL, before and after iodine supplementation. In 1983, the urinary iodine in 47.5% of the population studied was between 2 to 5 micrograms/dL, while in 1995, 65% of the population studied had urinary iodine between 10 to 25 micrograms/dL, 12 years after iodine supplementation. Mean serum T4, T3, and thyroid-stimulating hormone (TSH) were normal before and after intervention. There was no significant change in occurrence of positive antibodies, or of hypo- and hyperthyroidism, following iodine supplementation. CONCLUSION: The result of this study shows that the use of iodized salt causes an increase in excreted urinary iodine and a decrease in the prevalence of thyroid goiter, especially in younger age groups. Consumption of iodized salt with 40 parts per million (ppm) iodine has not caused increased prevalence of thyroid dysfunction in this area.     

Findings relating to goiter and iodine in the Ten-State Nutrition Survey.

Examinations for thyroid size were carried out on 35,999 individuals in the Ten-State Nutrition Survey. Overall goiter prevalence was found to be 3.1 per cent with the higher prevalence of goiter among adolescents and adults. Females of all ages had a higher prevalence of goiter than did males. No consistent regional pattern of the occurrence of goiter was observed. Urinary iodine excretion values used to estimate iodine intake indicated very few persons with excretion values suggesting iodine deficiency. No association between goiter and low iodine excretion was observed. On the contrary, a higher prevalence of goiter was found among persons excreting high levels of iodine. There is no indication from this study of widespread, iodine-deficiency goiter.     

Severe iodine deficiency in southern Albania

Albania does not yet have a national program for control of iodine deficiency and there are no recent data on the severity of the iodine deficiency disorders (IDD) in the country. The aim of the present study was to assess current IDD status in southern Albania. In primary school children in urban and rural areas urinary iodine concentration (UI) and iodine concentration in salt at retail and household levels was measured. Goiter was graded by palpation and thyroid volume determined by ultrasound. Children aged 5-14 yr (n = 826) were sampled at 2 urban and 5 rural primary schools. In the 2 urban schools, the median UI was 45 micrograms/L, the goiter prevalence was 32%, and salt iodine levels were inadequate (< 15 micrograms/g) in 78% of household salt samples. In the rural schools, the median UI was 17 micrograms/L, the goiter prevalence was 95%, and no household salt samples were adequately iodized. Among children in the rural schools, 73% had grade 2 goiter and 20% had nodular changes detected by thyroid ultrasound. In southern Albania, school children in urban areas are moderately iodine deficient and those in rural villages are severely iodine deficient. These findings suggest that regional distribution of oral iodized oil capsules is indicated to control IDD in vulnerable groups until salt iodization is implemented.     

Epidemiology of endemic goiter in Italy

Epidemiological surveys on goiter endemia carried out in Italy in the two last decades were recently reviewed. Iodine deficiency and endemic goiter were documented in the entire country. In recent studies, urinary iodine excretion was higher and prevalence of goiter was lower than that documented in the past, in absence of a national program of prophylaxis. Nevertheless, in a recent study carried out in Basilicata, in schoolchildren a goiter prevalence of 16% was documented. In conclusion, iodine deficiency and endemic goiter are still present in Italy; despite the beneficial effects of "silent prophylaxis", a iodine prophylaxis program is mandatory.     

Goiter and iodine deficiency in Veneto: study on 6285 elementary and media school children

The aim of this paper was to determine goiter prevalence and urinary iodine excretion in the Veneto region. An extensive epidemiological survey was carried out in school-aged children visiting 6285 students and testing 1861 urinary samples. A goiter prevalence of 8.8% was found: 7.7% of grade 1A and 1.1% 1B; in the pre-mountainous area the prevalence was higher than 10% (11.7% in the Treviso and 12.7% in the Vicenza area). Urinary iodine excretion was less than 100 micrograms/Cr in about 45% of all examined children with a peak of 20% under 50 micrograms/Cr in the Vicenza district. According to the WHO criteria, the goiter prevalence in the Veneto can be considered under the limits of the epidemic standards. However the use of iodized salt seems advisable also in this area.     

Iodine status of children living in areas with high nitrate levels in water

Several researchers have suggested a possible relationship between nitrate intake and the development of goiter in children. The present cross-sectional study included schoolchildren between the ages of 11 and 14 years from 2 villages in Bulgaria with high and low nitrate levels in drinking water. The comparison between the median urinary iodine levels of the total number of exposed (179.0 microg/l) and nonexposed (202.50 microg/l) children showed statistically significant differences. The relative risk for the children exposed to high nitrate levels in drinking water, expressed as the odds ratio, was 8.145 (95% confidence interval = 1.67-39.67). The authors considered this to be very significant. They found a statistically significant difference for the prevalence of goiter among the exposed and nonexposed children. The results of the study confirmed the role of high nitrate levels in drinking water as a health risk factor for thyroid dysfunction.     

The relation between serum ferritin and goiter,urinary iodine and thyroid hormone concentration

OBJECTIVE: Many children are at high risk of both goiter and iron deficiency in Iran. Because iron deficiency may impair the efficacy of iodine supplementation, the aim of this study was to determine the relation between serum ferritin and goiter, urinary iodine, and thyroid hormones following iodized salt supplementation. DESIGN: A cross-sectional study of schoolchildren in 26 Iranian provinces. METHODS: In a national iodine deficiency disorders (IDD) monitoring program, 36,178 schoolchildren, approximately 1200 from each province, received goiter grading by WHO criteria. Urine and serum samples were collected from 2917 children and assayed for urinary iodine and serum ferritin, T4, T3, and thyroid-stimulating hormone (TSH) concentrations. RESULTS: Total goiter rates were 80 and 20% in children with ferritin concentrations < 10 mg/dL and > or = 10 mg/dL, respectively (p < 0.001). Increased serum T3 and decreased resin T3 uptake was present in those with lower serum ferritin levels; however, free T3 and T4 index, serum T4, and TSH were not significantly different between those with low and normal ferritin. CONCLUSION: Iron deficiency is associated with a high prevalence of goiter in Iranian schoolchildren.     

An evaluation of salt intake and iodine nutrition in a rural and urban area of the C?te d'Ivoire.

OBJECTIVE: To evaluate the habitual salt intake of individuals living in the C?te d'Ivoire, and to monitor the iodine nutrition of adults, schoolchildren and pregnant women one year after implementation of a universal salt iodisation programme. DESIGN: A three day weighed food records with estimation of food intake from a shared bowl based on changes on body weight, determination of sodium and iodine concentrations in 24 h (24 h) urine samples from adults, and determination of urinary iodine in spot urines from schoolchildren and pregnant women. SETTING: A large coastal city (Abidjan) and a cluster of inland villages in the northern savannah region of the C?te d'Ivoire. SUBJECTS: For the food records: 188 subjects (children and adults) in the northern villages; for the 24 h urine collections: 52 adults in Abidjan and 51 adults in the northern villages; for the spot urine collections: 110 children and 72 pregnant women in Abidjan and 104 children and 66 pregnant women in the north. MAIN RESULTS: From the food survey data in the north, the total mean salt intake (s.d.) of all age groups and the adults was estimated to be 5.7 g/d (+/- 3.0), and 6.8 g/d (+/- 3.2), respectively. In the 24 h urine samples from adults, the mean sodium excretion was 2.9 g/d (+/- 1.9) in the north and 3.0 g/d (+/- 1.3) in Abidjan, corresponding to an intake of 7.3-7.5 g/d of sodium chloride. In the north the median 24 h urinary iodine excretion in adults was 163 microg/d, and the median urinary iodine in spot urines from children and pregnant women was 263 microg/l and 133 microg/l, respectively. In contrast, in Abidjan the median 24 h urinary iodine was 442 microg/d, with 40% of the subjects excreting > 500 microg/d, and the median urinary iodine in spot urines from children and pregnant women was 488 microg/l and 364 microg/l, respectively. Nearly half of the children in Abidjan and 32% of the pregnant women were excreting > 500 microg/l. CONCLUSION: Based on the estimates of salt intake in this study, an optimal iodine level for salt (at the point of consumption) would be 30 ppm. Therefore the current goals for the iodised salt programme--30-50 ppm iodine appear to be appropriate. However, in adults, children and pregnant women from Abidjan, high urinary iodine levels--levels potentially associated with increased risk of iodine-induced hyperthyroidism--are common. These results suggest an urgent need for improved monitoring and surveillance of the current salt iodisation programme in the C?te d'Ivoire.     

Epidemiology of endemic goiter in Tuscany

In the present study, the data of epidemiological surveys carried out in Tuscany from 1981 to 1993 in schoolchildren population (6-14 years) residing in extraurban hilly and mountain areas are reported. Mild iodine deficiency and high prevalence of goiter were documented in the epidemiological surveys carried out up to 1990. An increase in urinary iodine excretion with a dramatic decrease in goiter prevalence was documented in the more recent surveys, independently from iodine prophylaxis. The results observed in Garfagnana and in Val Tiberina after the implementation of iodized salt confirmed the necessity to promote prophylaxis programs extended to the entire population.     

2018年天津市水源性高碘地区学龄儿童碘营养现况调查

目的 了解水源性高碘地区学龄儿童碘营养现状及甲状腺肿大情况,为开展高碘危害防治工作提供参考依据。方法 从水源性高碘地区5个街/镇中,选择2 207名学龄儿童作为调查对象,采集儿童尿样测定尿碘含量,检测儿童甲状腺容积。结果 调查地区水碘含量范围是100.4～175.1 μg/L,各街/镇水碘中位数差异有统计学意义（χ2 = 19.422,P = 0.001）。儿童尿碘中位数为215.96 μg/L（141.88～307.66 μg/L）,男童尿碘中位数高于女童（Z = -2.768,P = 0.006）,各街/镇儿童尿碘中位数差异有统计学意义（χ2 = 71.981,P＜0.001）。儿童甲状腺容积中位数为3.2 mL（2.5～4.1mL）,甲肿率为3.7%。各街/镇儿童甲状腺容积中位数差异有统计学意义（χ2 = 311.402,P＜0.001）,甲肿率差异无统计学意义（χ2 = 7.117,P = 0.130）。水碘与尿碘（rs = -0.037,P = 0.084）、甲状腺肿大（rs = - 0.022,P = 0.302）,尿碘与甲状腺肿大（rs = - 0.027,P = 0.209）之间相关性均无统计学意义。结论 本次调查研究暂未发现水碘、尿碘与甲状腺肿大之间的关联性。水源性高碘地区学龄儿童碘营养处于超足量水平,甲肿率高于我国多个省份,有关部门应当引起重视,因地制宜的制定防治方案。     

Persistence of iodine deficiency in Gangetic flood-prone area, West Bengal, India

In 2000, India revoked the ban on production and sale of non-iodised salt. We conducted a study in the north 24 Parganas district in the state of West Bengal to assess the prevalence of goitre, status of urinary iodine excretion (UIE) level and to estimate iodine content of salts at the household level. We surveyed 363 school children aged eight to ten years selected using a multistage cluster sampling technique. We estimated goitre prevalence and urinary iodine excretion (UIE) using methods and criteria recommended by the World Health Organization. We estimated the iodine content of salt samples collected from the households of the study subjects using spot iodine testing kit. Of the 363 children, 73 (20%) had goitre. The median UIE was 160 micro g/l (normal: > or =100 micro g/l) and only 6% children had a level below 50 micro g/l. Only 253 of 363 salt samples (70%) were sufficiently iodised. The combination of high goitre prevalence with normal median urinary excretion indicates that the North 24 Parganas district is in transition from iodine deficient to iodine sufficient state. However, the persistence of non-iodised salt consumption indicates that an intensification of universal salt iodisation program is needed. In 2000, India revoked the ban on production and sale of non-iodised salt. We conducted a study in the north 24 Parganas district in the state of West Bengal to assess the prevalence of goitre, status of urinary iodine excretion (UIE) level and to estimate iodine content of salts at the household level. We surveyed 363 school children aged eight to ten years selected using a multistage cluster sampling technique. We estimated goitre prevalence and urinary iodine excretion (UIE) using methods and criteria recommended by the World Health Organization. We estimated the iodine content of salt samples collected from the households of the study subjects using spot iodine testing kit. Of the 363 children, 73 (20%) had goitre. The median UIE was 160 micro g/l (normal: > or =100 micro g/l) and only 6% children had a level below 50 micro g/l. Only 253 of 363 salt samples (70%) were sufficiently iodised. The combination of high goitre prevalence with normal median urinary excretion indicates that the North 24 Parganas district is in transition from iodine deficient to iodine sufficient state. However, the persistence of non-iodised salt consumption indicates that an intensification of universal salt iodisation program is needed.