Three-year survey of effects of iodized oil injection in schoolchildren with iodine deficiency disorders.

High prevalence of goiter, other IDD such as impaired physical and intellectual growth and hearing deficit have been reported previously in Kiga. In order to evaluate the effect of iodized oil injection, this study was conducted in schoolchildren of Kiga village from 1989 to 1992. One ml of iodized oil solution containing 480 mg of iodine was injected into 198 schoolgirls and boys aged 8-14 years. Serum thyroid hormones, RT 3 U, TSH and thyroglobulin, before and 12, 24 and 36 months after the intra-muscular injection of iodized oil were measured. Assessment of urinary iodine was performed at the same periods by Foss method. Prior to the injection, all schoolchildren had goiters larger than grade 1 A (48% were grade 3); 3 years after intervention 20% had grades zero and 1 A and 8% grade 3 (P < 0.001). Urinary iodine was 11.4 +/- 19.8 before and increased to 113 +/- 63 and 83 +/- 66 microg/g creatinine 2 and 3 years after intervention. Mean serum T 4 was 5.0 +/- 2.1, 10.8 +/- 2.8, 9.8 +/- 2.5 and 9.5 +/- 2.1 microg/dl before and 12, 24 and 36 months after the injection, respectively (P < 0.001). Mean serum TSH was 20.3 +/- 22.8, 1.2 +/- 1.6, 0.8 +/- 1.2 and 2.2 +/- 0.9 mU/L in the same intervals, respectively (P < 0.001). Mean serum thyroglobulin was 132 +/- 107, 10 +/- 12 and 23 +/- 20 ng/ml before and at 2 and 3 years after injection, respectively (P < 0.001). Slight but significant increases in serum TSH and thyroglobulin occurred at 3 years after the injection. Findings show benefits of iodized oil administration in decreasing goiter size and in resuming normal thyroid function up to 3 years after the intervention. An increase in TSH and or thyroglobulin could be considered as the first sign of a fall in effectiveness of iodized oil injection.     

新疆和田地区学龄儿童碘缺乏与听力关系的研究

本文使用日本MST-1N型听力计,于1989年9～10月间对新疆和田地区181名7～14岁学童进行了双耳纯音气导听力测定。测定对象共分4组(处于不同海拔高度上的3组缺碘学童及1组补碘对照组学童)。除测定听力外,还测定了智商、甲状腺吸~(131)I率、T_3、T_4、TSH、精神运动发育和骨龄等项指标。结果表明,缺碘地区学童平均听阈显著高于补碘对照组;听力损失在高频(8000Hz)及低频(1000Hz)最为严重;平均听阈与下列因素有显著负相关关系存在:海拔高度、性别、身高、体重、身高体重指数、敲击试验及智商。提示缺碘造成的听力障碍主要为高频(8000Hz)及低频(1000Hz)。采取补碘措施后,听力可有部分恢复,但不能完全恢复。平均听阈与甲状腺吸~(131)I率、T_3、T_4、TSH等指标无显著相关,故是一个较为独立的指标,把它作为亚临床克汀病的辅助诊断指标是合适的。     

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

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

碘硒联合补充控制碘缺乏病效应的研究

为了探讨联合补充碘硒控制碘缺乏病的效应,作在外环境缺碘地区,对实验组小学生在供应碘盐的同时每月口服一次２００ｍｇ亚硒酸钠片,对照组小学生单纯食用碘盐,２年后观察小学生甲状腺肿大率,尿碘、发硒和血清ＴＳＨ、Ｔ４、Ｔ３和ＦＴ３变化。     

Neuropsychological assessment in schoolchildren from an area of moderate iodine deficiency

Neuropsychological assessment was carried out in schoolchildren from a montane area of Eastern Tuscany (Tiberina Valley). This area was found to be moderately iodine deficient (mean urinary iodine excretion: 39 micrograms/g creatinine), with a cumulative goiter prevalence of 51.9% in schoolchildren aged 6-14 yr (goiter prevalence in the control iodine-sufficient area: 5.6%). No significant differences in serum TT4, TT3, FT4I, TSH levels between the endemic and control areas were found, whereas serum thyroglobulin values were significantly higher in the iodine-deficient area (61 +/- 8 vs 17 +/- 1 ng/ml, p less than 0.01). No differences were found as to the height, body weight and pubertal development in the two areas. Neuropsychological assessment, performed in a representative sample of 50 schoolchildren from the endemic area and 50 schoolchildren from the control area, matched for age, sex and socioeconomical conditions, failed to show major differences between the two groups in the global neuropsychological performance and cognitive levels. However, minor but significant differences were noted in the information vocabulary and coding subtests, at least in children aged 8. Although familial cultural influences might play a role, it would appear that some marginal impairment, with particular regard to motor-perceptual functions, be present in areas of moderate iodine deficiency.     

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.     

Reappraisal of the risk of iodine-induced hyperthyroidism: an epidemiological population survey

The occurrence of iodine-induced hyperthyroidism (IIH) has been reported after iodine supplementation from clinics and hospitals, but not following an epidemiologic survey. We studied the prevalence of thyroid derangement in a population following iodine supplementation. One yr after more than 75% of the population had been consuming 40 ppm iodized salt; information regarding history of endemic goiter and iodized salt production, distribution, consumption and monitoring were collected in four cities of the Islamic Republic of Iran. A total of 6048 subjects were randomly selected. All subjects were assessed for size of goiter, and urinary iodine and serum T4, T3, TSH, anti-thyroglobulin and anti-thyroperoxide were measured. Before iodine supplementation, all four cities were areas of endemic goiter. The rate of household consumption of iodized salt was 50, 75 and 90% in 1994, 1995 and 1996, respectively. Ninety-one percent of the salt samples contained 15-55 ppm iodide. Total goiter rate was 57, 62 and 68%; median urinary iodine was 188, 197 and 190 microg/l in the age groups of 6-18, 19-40 and >40 yr, respectively. Prevalence of clinical and subclinical hyperthyroidism was 0.34 and 0.41 and those of clinical and subclinical hypothyroidism were 0.51 and 1.07%, respectively. Nine point eight and 18% in the 19-40 yr age group and 17.6 and 25.6% in >40 yr old subjects had positive anti-thyroperoxidase and anti-thyroglobulin, respectively. This systemic epidemiologic study in an iodine deficient population showed that, following a well-executed iodine supplementation program, the occurrence of IIH is rare.     

Milk represents an important source of iodine in schoolchildren of the Veneto region, Italy

The aim of the present study is to evaluate the relationships between urinary iodine concentration (UIC) and the intake of milk and other foods, in a group of school children of the Veneto region, in North East Italy. A questionnaire, concerning the daily intake of milk, yoghurt, cheese and other animal foodstuffs, was distributed to 233 schoolchildren aged between 11 and 15 yr. The use of iodized salt was also investigated. UIC was measured in a casual urine sample of all children investigated. The iodine content of 28 samples of milk and of 13 samples of yoghurt, bought during the summer in shops of the same area, was measured. UIC values ranged between 25 and 436 microg/l, median value was 140 microg/l, mean value 149+/-78 microg/l. The median iodine content of milk and yoghurt were 278 microg/l and 216 microg/l, respectively. With regard to dietary habits, about 70% of the children took 200 ml of milk or more per day, which corresponds to a daily intake of iodine ranging between 50 and 100 microg a day. About 30% of schoolchildren used iodized salt. A highly significant correlation between UIC and milk intake was observed (p=0.0005), while the relationship was poor or absent in the case of both intake of other foodstuffs and use of iodized salt (p=0.38). In conclusion, the results of the study document the very important role of cows' milk as a source of iodine in childhood in the Veneto region, Italy.     

不同碘营养水平对育龄妇女甲状腺功能的影响

目的 研究不同碘营养水平对育龄妇女甲状腺功能的影响.方法 选择新疆巩留县和伊宁县各50名育龄妇女(非孕)作为碘充足组和碘缺乏组,按统一设计的调查项目表,逐项询问、检查、填写;内容包括家庭食用盐和饮用水的种类,个人甲状腺疾病史和甲状腺肿大情况.采集调查对象饮用水、食盐、尿液,分别用直接滴定法、砷铈催化分光光度法检测含碘量;采集并用化学发光免疫法检测静脉血清中的TSH、FT4、FT3水平.结果 碘缺乏组和碘充足组碘盐覆盖率分别为72%和100%,前者低于后者(χ2=16.28,P<0.01);尿碘中位数分别为95.5μg/L[四分位间距(QR)=50.0μg/L]和167.4μg/L(QR=186.4μg/L),前者低于后者(U=632.00,P<0.01);血清TSH中位数分别为2.56、1.88 mU/L,前者有高于后者的趋势,但差异无统计学意义(U=990.50,P>0.05);血清FT4分别为(14.7±2.0)、(17.0±3.8)pmoI/L,前者明显低于后者(t=3.76,P<0.01);血清FT3分别为(5.1±1.4)、(4.8±0.5)pmoI/L,二者比较差异无统计学意义(t=1.59,P>0.05);FT3/FT4比值分别为0.33±0.04、0.30±0.04,二者比较差异有统计学意义(t=3.13,P<0.01);甲状腺功能异常检出率分别为20.0%(10/50)、8.0%(4/50),二者比较差异无统计学意义(χ2=2.99,P>0.05).结论 育龄妇女的碘营养缺乏是导致自身甲状腺功能低下的主要原因,坚持长期食用碘盐是彻底纠正机体缺碘状况的最有效方法.     

Maternal thyroid function in different conditions of iodine nutrition in pregnant women exposed to mild-moderate iodine deficiency: an observational study

Objective We examined the effect of different conditions of nutritional iodine intake on maternal thyroid function throughout gestation in a cohort of healthy, anti‐thyroid antibody‐negative women from a mild‐moderately iodine‐deficient (ID) area. Design Observational cohort study. Patients The study included 168 women receiving prenatal preparations containing 150 μg of iodine from early pregnancy (150‐I group); 105 women who had regularly used (>2 years) iodized salt prior to becoming pregnant (I‐salt group); 160 women neither taking iodine supplements nor using iodized salt (no‐I group). Measurements Maternal TSH, FT3 and FT4 were determined throughout gestation. Results Mean TSH concentrations were higher among the 150‐I women than in the remaining two groups, and in a high proportion of them, TSH values were found to exceed the upper limit for gestational age. Conversely, the prevalence of low free‐thyroxine levels in the 150‐I women was similar to that observed in the I‐salt women and markedly lower than that recorded for the no‐I group. Conclusions The regular use of iodine‐containing supplements proved effective in reducing the risk of inappropriately low FT4 levels during pregnancy. The observed TSH increase in 150‐I women may be because of a transient stunning effect on the thyroid gland, occurring as a result of the abrupt increase in daily iodine intake. Whilst the importance of gestational iodine supplementation is undisputed, we believe that in mild‐moderately ID areas, women considering conception should be advised to take iodine supplementation for several months prior to pregnancy.     

The effectiveness of oral iodized oil in the treatment and prophylaxis of endemic goiter

In a longitudinal study carried out for 2 yr in the Darfur region, western Sudan, 2316 school children received a single dose of 2 capsules of iodized oil (400 mg iodine) orally, and 1161 school children received 1 ml of the same preparation im (475 mg iodine); 2393 school children served as controls. One year after treatment, goiter prevalence was reduced from 67.0% to 36.0% among the children who had received oral iodized oil and from 71.0% to 42.0% in those who received it im. The prevalence in the control group did not change. The prevalences in each group were approximately the same 2 yr after treatment. Urinary iodine excretion increased after treatment and remained significantly higher than the initial value during the trial. In subjects from rural Darfur, serum T4 levels were increased 1 yr after treatment with oral iodized oil (P less than 0.001) and im iodized oil (P less than 0.01), and remained high in the former (P less than 0.05) but not in the latter. This increase was accompanied by reduction of serum T3 and TSH levels. Sialadenitis occurred in 3.7% of the children who received oral iodized oil. Thyroid antibodies were not detected before treatment, but microsomal antibodies were detected in 2 of the 128 subjects studied who received iodized oil orally. Comparable results occurred when oral and im iodized oil were given to 841 individuals covering a wider age range. It is concluded that a single oral dose of iodized oil is effective in the correction of iodine deficiency, reducing the goiter size and preventing the recurrence of goiter for at least 2 yr.     

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

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

山东省碘缺乏地区重点人群碘营养调查

目的 了解山东省当前盐碘水平状态下,碘缺乏地区重点人群碘营养状况及防治措施落实情况,为今后防治工作提供依据.方法 2007年,在山东省碘缺乏地区选择山区的岱岳、蒙阴,平原的莒县、高密,沿海的招远,共5个县(市、区)作为调查地区,在每个县(市、区)选择1个乡(镇)作为调查点.采用触诊、B超法进行8～10岁儿童甲状腺检查,直接滴定法检测其家中食用盐含碘量;砷铈催化分光光度法检测8～10岁儿童、孕妇、哺乳期妇女、2岁内婴幼儿及20～45岁育龄妇女5种重点人群的尿碘水平.结果 共检查514例8～10岁儿童甲状腺,触诊甲状腺肿大率为1.8%(9/514),B超检查甲状腺肿大率为1.2%(6/514);共检测501份食用盐,盐碘均值为30.95 mg/kg,碘盐覆盖率为94.6%(474/501),合格碘盐食用率为90.4%(453/501);共检测1707份尿样,尿碘中位数为216.7μg/L,8～10岁儿童、孕妇、哺乳期妇女、2岁内婴幼儿及20～45岁育龄妇女尿碘中位数分别为234.0、165.5、162.4、257.5、233.0μg/L.结论 山东省碘缺乏地区重点人群碘营养水平处于适宜或较适宜状态.表明目前盐碘水平能够满足山东省不同碘缺乏地区人群对碘的需求.

Abstract：

Objective To learn the iodine nutritional status of the vulnerable population with different iodine level under the current level of iodized salt in Shandong province and to offer prevention and cure measures.Methods Five groups of vulnerable population including school children aged 8 - 10, pregnant, lactation women, infants and women of childbearing age from mountain areas ( Daiyue, Mengyin counties ) , plain ( Luxian,Gaomi counties ) and coastal (Zhaoyuan county ) of five different iodine deficient areas were investigated in 2007.The thyroids of children aged 8 - 10 were checked by palpation and B ultrasound, their edible salt iodine level was detected by direct titration. The lever of urinary iodine of vulnerable population was examined by arsenic and cerium speetrophotometry. Results The goiter rates of 8 - 10 year-old were 1.8%(9/514) and 1.2%(6/514), respectively by palpation and B-ultrasonic. The mean iodine of 501 edible salt samples was 30.95 mg/kg. The coverage rate of iodized salt was 94.6% (474/501). The rate of qualified iodized salt was 90.4% (453/501). The median of urinary iodine was 216.7 μg,/L. The urinary iodine of school children aged 8 - 10, pregnant, lactation women, infants and women of childbearing age were 234.0, 165.5, 162.4, 257.5, 233.0 μg/L, respectively. Conclusions Current iodine nutritional level is basically appropriate in all groups of vulnerable people. The current iodine content of iodized salt could meet the needs of population from different iodine deficient areas of Shandong province.     

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.     

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.     

Evaluation of goiter using ultrasound criteria: a survey in a middle schoolchildren population of a mountain area in Central Italy

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.     

Goiter rate, serum thyrotropin, thyroid autoantibodies and urinary iodine concentration in Tehranian adults before and after national salt iodization

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.     

The auditory threshold in a school-age population is related to iodine intake and thyroid function.

The aim of this study was to determine the relationship between auditory capacity and urinary iodine, taking into account thyroid volume and function, in a population of school-age children. Audiometry was carried out in 150 children (ages 6-14 years), together with measurements of thyroid volume, thyrotropin (TSH), free T3, free T4, thyroglobulin, antiperoxidase and anti-TSH receptor antibodies, as well as iodine in a casual urine sample. Children with a TSH >5 microU/mL were excluded from the study. In the children with palpable goiter, there was an inverse relation between the auditory threshold at all frequencies and ioduria. Children with thyroglobulin values >10 ng/mL had a higher auditory threshold at all frequencies. In the children with palpable goiter and ioduria <100 microg/L, the levels of thyroglobulin and ioduria and the age accounted for 75% of the decibel (dB) variance at 2000 (Hertz), with similar results at other frequencies. The children with a thyroid sized at the >95th percentile had an odds ratio of 3.86 (95% confidence interval: 2.59-5.10) of having a threshold >20 dB. The results warn that iodine prophylaxis is needed to prevent not only goiter but also other iodine-deficiency disorders, such as involvement of the auditory threshold in school-age children.     

Iron supplementation in goitrous, iron-deficient children improves their response to oral iodized oil

OBJECTIVE: In developing countries, many children are at high risk for both goiter and iron-deficiency anemia. Because iron deficiency may impair thyroid metabolism, the aim of this study was to determine if iron supplementation improves the response to oral iodine in goitrous, iron-deficient anemic children. DESIGN: A trial of oral iodized oil followed by oral iron supplementation in an area of endemic goiter in the western Ivory Coast. METHODS: Goitrous, iodine-deficient children (aged 6-12 years; n=109) were divided into two groups: Group 1 consisted of goitrous children who were not anemic; Group 2 consisted of goitrous children who were iron-deficient anemic. Both groups were given 200mg oral iodine as iodized oil. Thyroid gland volume using ultrasound, urinary iodine concentration (UI), serum thyroxine (T(4)) and whole blood TSH were measured at baseline, and at 1, 5, 10, 15 and 30 weeks post intervention. Beginning at 30 weeks, the anemic group was given 60mg oral iron as ferrous sulfate four times/week for 12 weeks. At 50 and 65 weeks after oral iodine (8 and 23 weeks after completing iron supplementation), UI, TSH, T(4) and thyroid volume were remeasured. RESULTS: The prevalence of goiter at 30 weeks after oral iodine in Groups 1 and 2 was 12% and 64% respectively. Mean percent change in thyroid volume compared with baseline at 30 weeks in Groups 1 and 2 was -45.1% and -21.8% respectively (P<0.001 between groups). After iron supplementation in Group 2, there was a further decrease in mean thyroid volume from baseline in the anemic children (-34.8% and -38.4% at 50 and 65 weeks) and goiter prevalence fell to 31% and 20% at 50 and 65 weeks. CONCLUSION: Iron supplementation may improve the efficacy of oral iodized oil in goitrous children with iron-deficiency anemia.     

Short and long term effects of radioiodine treatment on the iodine content of the thyroid gland

Thyroid iodine content (TIC) was measured in nine patients with hyperthyroid Graves' disease for 5-26 months after treatment with 131I (100-125 muCi/g tissue). In all patients, TIC decreased; in eight patients it became undetectable within 5 +/- 3 (SD) months. This fall was parallel to those of serum T3 and T4 levels and was not prevented by the administration of large doses of stable iodine. In four patients, this decrease was irreversible and they became clinically hypothyroid. In the five other patients, it was partly reversible: the secondary increase of TIC was parallel to those of serum T3 and T4 and to a decrease in TSH levels. These data suggest that during the months after 131I treatment, determination of TIC may help to distinguish transient from irreversible hypothyroidism. The late effects of 131I were studied in 38 patients who had been treated for hyperthyroid Graves' disease from 1.5-22 yr previously. The 16 patients who, at the time of examination, were euthyroid with normal serum TSH levels (less than 8 microU/ml) had a TIC [3.2 +/- 3 (SD) mg] significantly lower than that of 10 euthyroid patients previously treated only with antithyroid drug therapy (16.7 +/- 8.2 mg). A significant negative correlation was found between log basal TSH and log TIC (r = 0.61, P less than 0.001) and a positive correlation between log T4 and log TIC (r = 0.56, P less than 0.002). The T3/T4 ratio in patients with undetectable TIC (19.9 +/- 7.9) was higher than that of the other patients (14.6 +/- 3.2) (P = 0.02, Wilcoxon test). This hormonal profile was not modified by iodide supplementation, which increased TIC only transiently. The turnover of thyroid iodine was accelerated, which appeared to be the consequence of a small thyroid functional mass and of hyperstimulation by TSH.