Thiocyanate in excess develops goiter followed by auto immune thyroid diseases even after effective salt iodization in a rural community of north east India

PURPOSE

Salt iodization in Manipur of north-east India failed to prevent endemic goiter, therefore an in depth study carried out to evaluate thyroid functions of goitrous subjects in a randomly selected region.

METHODS

Goiter survey conducted in children and women of reproductive ages by palpation followed by measurement of urinary iodine, thiocyanate and house-hold salt iodine to evaluate iodine nutritional status and consumption pattern of bamboo-shoots (BS). In all grade-2 goitrous subjects, free thyroxine, triiodothyronine, TSH, TPO and Tg antibodies, thyroid volume and echogenecity by ultrasonography and cytomorphology of thyroid by FNAC studied.

RESULTS

Study population was 2486 children and 1506 women, goiter prevalence was 12.59% and 16.27% respectively; median urinary iodine and mean thiocyanate were 166 µg/l and 0.729 ± 0.408 mg/dl while salt iodine was ≥30 ppm. Serum thyroid hormones and TSH profiles of all grade-2 goitrous subjects showed 16.21% were subclinically hypothyroid, 2.16% overt hypothyroid, 4.86% subclinically hyperthyroid and 6.48% overt hyperthyroid, serum TPO- and Tg-antibodies found positive in 41.62%. Ultrasonographic results showed 24% had enlarged thyroid and 86.4% hypoechoic. Cytomorphological studies showed prevalence of colloid goiter (41.08%), lymphocytic thyroiditis (37.83%), Hashimoto's thyroiditis (8.10%), autoimmune thyroiditis (4.32%), sub-acute thyroiditis (2.16%) and 1.62% each papillary, medullary carcinoma, simple diffused hyperplasia and adenomoid nodular goiter.

CONCLUSIONS

Grade-2 goitrous individuals in this mild goiter endemic region were affected by hypo- and hyperthyroidism with hypoechoic thyroid and thyroiditis. Thiocyanate that originates from BS even in presence of adequate iodine developed goiter and led goitrous population towards such diseases.

Iodine Deficiency and Toxicity Among School Children in Damoh District, Madhya Pradesh, India

OBJECTIVE

To estimate the prevalence of Iodine Deficiency Disorders, and household consumption of adequately iodized salt in Damoh district, Madhya Pradesh in 2016.

METHODS

Cross-sectional study with cluster sampling method was used among school-going children. 30 clusters, each with 90 children were selected to access Total Goiter rate (TGR). 540 salt samples were collected to estimate salt iodine content from their household and 270 on the spot urine samples were collected to estimate Urine Iodine Excretion level.

RESULTS

TGR was 2.08%. The prevalence of iodine deficiency, adequate iodine nutrition, and either more than adequate or toxic level of Iodine was 26%, 28% and 46 %, respectively. 72.4% people were consuming adequately iodized salt.

CONCLUSION

Damoh district is no more an endemic area for iodine deficiency. We recommend continuous monitoring to assess IDDs as well Iodine-induced toxicity in future.

Effect of maternal iodine supplementation on thyroid function and birth outcome in goiter endemic areas

OBJECTIVE

The study was undertaken to examine the clinical and endocrine parameters of thyroid in a total of 460 pregnant women belonging to non-goiter areas (group 1; n = 156) and endemic areas without (group 2; n = 154) and with iodine supplementation (group 3; n = 150), and their respective newborns.

METHODS

Women of group 3 with visible goiter were administered two capsules of iodized oil orally each containing 200 mg of iodine, from weeks 6--8 of pregnancy. Blood samples were obtained from all groups during each trimester, at parturition (umbilical cord blood) and after delivery. Serum triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH) levels were measured by specific enzyme immunoassays.

RESULTS

In group 2, serum T4 concentrations were low while T3 and TSH levels were high which showed hypothyroidism in the women of endemic areas. Goiter size decreased in most of the subjects who received a single dose of iodized oil and resulted in increase in serum concentrations of thyroid hormones; whereas, TSH levels decreased. Iodine supplementation also resulted in raised T4 and low TSH levels in the cord blood of neonates. During the course of study, two abortions, three still births and one cretin were reported in group 2; none was reported in group 3; and one still birth was reported in group 1.

CONCLUSIONS

The oral administration of a single dose of iodized oil is capable of correcting iodine deficiency both clinically and endocrinologically in mothers and neonates. Iodine supplementation has the potential to positively impact the birth weight of newborns.

Malignancy rates in operated patients with hyperthyroidism in an area of endemic goiter

We aimed to evaluate the incidence of thyroid cancer in Turkish patients with hyperthyroidism who had undergone thyroid surgery. The data of 344 patients who had been operated on for hyperthyroidism between 1998 and 2006 at our center were evaluated retrospectively. Sixty-five of the subjects had single toxic adenomas, 223 had toxic multinodular goiter, and 56 had Graves' disease. In 35 of 344 patients (10.1%), papillary carcinoma was diagnosed. Other forms of thyroid carcinomas were not observed. The rate of carcinoma was found to be 11.6% in patients with toxic multinodular goiter, 7.7% in patients with single toxic adenomas, and 7.1% in patients with Graves' disease. Occult papillary carcinoma was found in 62.9% of all malignancy diagnoses. The primary aim in the surgical treatment of hyperthyroidism should be to abolish the hyperthyroid state. However, the probability of malignancy, especially occult carcinoma, should always be considered.

Inadequate iodine nutrition of pregnant women from Extremadura (Spain)

OBJECTIVE

To evaluate the iodine nutrition of the pregnant women of the Spanish Autonomous Community Extremadura. There are approximately 10,000 births per year in Extremadura, which historically contains areas with endemic goiter (Las Hurdes).

DESIGN

Population study in which a representative sample of pregnant women of the general population was analyzed, along with another sample of pregnant women from traditionally goitrogenic areas. With the collaboration of selected health centers, an additional sample of blood and urine was obtained within the primary health care pregnancy-monitoring program; these samples were sent to a single central laboratory.

METHODS

Biochemistry: determination of iodine and creatinine in urine, and serum concentrations of thyroxine, free thyroxine, tri-iodothyronine, TSH, thyroglobulin, and two anti-thyroid antibodies. Each parameter was measured by means of a single specific RIA.

RESULTS

Changes between the first trimester and later stages of pregnancy of all biochemical variables studied corresponded with those described for other European areas with a comparable iodine nutrition. Using the urinary iodine concentration value as an indicator of iodine ingestion, it was found that in the first trimester of pregnancy six out of ten women from Extremadura ingested less than the currently recommended amount (250 microg I/day), and approximately three out of ten of these women ingested less than half of this amount.

CONCLUSIONS

It is imperative to implement in all Extremadura the generalized and controlled use of complements that contain 200-250 microg I/day throughout pregnancy and, if possible, before.

Evaluation of endemic goiter prevalence in Bulgarian schoolchildren: results from national strategies for prevention and control of iodine-deficiency disorders

Iodine deficiency is a major health problem worldwide. The environment of the Balkan countries, including Bulgaria, is distinguished for its low iodine content. In 1994, the strategies for the prevention and control of iodinedeficiency disorders were actualized in Bulgaria and universal salt iodization and supplementation for the risk population groups (schoolchildren, pregnant women) were introduced. The aim of this study was to assess the effectiveness of the iodine prophylaxis in schoolchildren, living in an endemic for goiter area after the introduction of salt iodization in Bulgaria. For this purpose, the goiter prevalence and iodine status in 483 schoolchildren (274 boys and 209 girls) aged between 8 and 15 yr, living in an endemic for goiter area in Bulgaria were evaluated. Despite the normalization of iodine supply, mild iodine deficiency on the basis of goiter prevalence (16.15%) and urinary iodine excretion was found. These data indicate the need for reevaluation of the national strategy for prevention of iodine deficiency.

Situación nutricional de yodo en la población escolar de Alicante

BACKGROUND

According to the World Health Organization (WHO), goiter is endemic in Spain. The main cause of endemic goiter is iodine deficiency, which is also the principal cause of mental retardation and avoidable cerebral palsy throughout the world.

MATERIAL AND METHODS

We conducted an observational study to determine the prevalence of endemic goiter and nutritional iodine status in the province of Alicante. Urinary iodine excretion was measured in a morning urine sample, and thyroid volume was measured by means of a thyroid ultrasound scan. A case of goiter was diagnosed if thyroid volume was above the 97th percentile adjusted by age, as published by the WHO.

RESULTS

No cases of goiter were found. In addition, the median urinary iodine excretion levels adjusted by age were within the normal range, as defined by the WHO's criteria.

CONCLUSIONS

Endemic goiter was not found in the province of Alicante and urinary iodine excretion values demonstrated adequate iodine intake. Further ultrasound studies are needed to establish reference thyroid volumes for our population.

Bocio endémico y déficit de yodo: ¿sigue siendo una realidad en España?

OBJECTIVE

To estimate the prevalence of goiter and iodine deficiency in a health district in the Autonomous Community of Valencia, given the absence of data in this region of Spain.

MATERIAL AND METHODS

We conducted a descriptive, epidemiologic, cross-sectional study, stratified by age and sex, in four interior regions of the province of Valencia. We selected students aged from 6 to 14 years old in 20 centers. Thyroid examination was performed by means of palpation and inspection (goiter > or = 0B). Urinary iodine excretion was analyzed in a routine urine sample. Sociodemographic and anthropometric data, as well as nutritional iodine status, were recorded in a standardized survey. In children with goiter, thyroid-stimulating hormone (TSH), free T4, and antithyroid antibodies were determined.

RESULTS

We studied 928 children (478 boys and 450 girls). The prevalence of goiter was 33.7 % (95 % CI: 30.7-36.9 %). There were no significant differences in the prevalence of goiter by age or sex, but an inverse correlation was detected between the prevalence of goiter and parental socioeconomic position. Mean urinary iodine excretion was 155 .g/l, with no significant correlation with the prevalence of goiter. In children with goiter, 13 had positive antithyroid antibodies, 18 had high TSH (subclinical hypothyroidism), and one had suppressed TSH (subclinical hyperthyroidism).

CONCLUSIONS

There is endemic goiter in the region studied. Urinary iodine levels were in the normal range and could be interpreted as indicating a transition phase to an improvement in iodine deficiency. Autoimmune diseases would only explain 4 % of cases of goiter.

Nutritional Epidemiology and Thyroid Hormone Metabolism

Severe iodine deficiency was the main cause of endemic goiter and cretinism. Most of the previously iodine-deficient areas are now supplemented, mainly with iodized salt. The geographical distribution of severe endemic areas has been progressively reduced, and at present, approximately 200 million people living in remote places are still at risk of severe iodine deficiency. International public health programs should be focused first on reaching these populations, and second on auditing and monitoring the operational work of supplementation programs. This second point is essential to prevent iodine-induced hyperthyroidism or interruptions of iodine supplement distribution, which could be catastrophic for the fetus and the young infant. Echography brings a complementary tool to clinical assessment of goiter by palpation. Inductively coupled plasma-mass spectrometry brings at least a definitive gold standard for iodine measurement and thyroid hormone measurement. Thiocyanate overload has been clearly documented as a goitrogen in Central Africa, and when associated with selenium deficiency, it may be included as risk factor for endemic myxedematous cretinism. Variable exposure to different environmental risk factors is likely the explanation of the variable distribution of two types of endemic cretinism (neurological and myxedematous), and the clinical overlap of the pathogeny of both syndromes is more important than previously described. It is possible that Kashin-Beck osteoarthropathy is another evanescent endemic disease that will disappear with the correction of iodine deficiency.

Determination of iodine concentration in urine by isotope dilution analysis and thyroid volume of school children in the west coast of Turkey after mandatory salt iodization

OBJECTIVE

This study was designed to evaluate iodine deficiency status in children 6-12 years in the west coast (Aegean Region) of Turkey after 5 years of mandatory iodine prophylaxis. A total of 2300 children from 72 populations (rural and urban area) were evaluated with urinary iodine excretion and thyroid volume.

DESIGN

Cross-sectional, observational study designed and performed according to surveillance methods for iodine deficiency disease (IDD) prevalence recommended by WHO/UNICEF/ICCIDD.

SUBJECTS

The study population consisted of 2300 school children age ranging from 6 to 12 years. The children were selected by multiple stage randomization from 91 primary schools of 76 zones (91 clusters). Information about the use of iodized salt was obtained from the families.

MEASUREMENTS

Data on the following were collected: birth date, sex, weight, height, thyroid size by palpation and ultrasonography; and urinary iodine by isotope dilution analysis method. Thyroid volumes above 97th percentile according to the WHO/ICCIDD by age and body surface area (BSA) were accepted as goitre.

RESULTS

Iodized salt consumption was 51.7%. The prevalence of goitre determined by palpation was 12.1% and by ultrasound based on BSA and age were 9.8% and 5.5%, respectively. Median urinary iodine was 53 (2-142) microg/l.

CONCLUSION

Mild to severe degree of iodine deficiency was detected in the west coast of Turkey.

Clinical importance of solitary solid nodule of the thyroid in endemic goiter region

CONTEXT

Endemic area and iodine supplementation may affect the pathogenesis of the nodule which commonly occurs in endemic thyroid enlargement due to iodine deficiency.

AIMS

To establish pathological changes in solitary solid and larger nodule of the thyroid in endemic area.

SETTING AND DESIGN

Retrospective study in Surgical Department of University Hospital.

METHODS AND MATERIAL

We determined 44 surgically treated patients with solitary solid nodule in endemic goiter area in which the population routinely receives iodinated salt. The thyroid nodule was preoperatively evaluated with blood chemistry, ultrasound, nuclear scanning and FNAC. The results of preoperative evaluation, surgical interventions, and histopathological examination were analyzed.

STATISTICAL ANALYSIS

Student t test and Fisher's exact test.

RESULTS

Twenty (45%;20/44) patients with hot (autonomous) nodule have received the diagnosis of toxic adenoma. Twenty four patients had solitary solid and cold nodule. Total thyroidectomy was performed on two patients with papillary cancer (PTC) diagnosed by FNAC from cold nodules. Forty two patients have been treated with total excision of the lobe including hyper or hypoactive solitary solid nodule. Pathological examination has reported two more cases of PTC and one case of insular cancer arising from cold nodules. Completion thyroidectomy was performed on these 3 patients.

CONCLUSIONS

Solitary solid and large nodule is a common indication for thyroid surgery in endemic goiter area. High incidence of hyperthyroidism due to single autonomous nodule, and high rate of malignant change (mainly papillary cancer) in solitary hypoactive nodule arises from this series in endemic thyroid enlargement.

Surgery is the procedure of choice for the treatment of patients with toxic adenoma in an endemic goitre area

PURPOSE

Toxic adenoma is one of the main causes of hyperthyroidism. We investigated the efficacy of surgery in the treatment of toxic adenoma.

METHODS

Serum thyroid stimulating hormone (TSH) measurement, ultrasound and scintigraphy of the thyroid were made for diagnostic purpose. The safety of surgery was evaluated by postoperative clinical course of patients. The efficacy of surgery was determined by the function of the remaining thyroid tissue.

RESULTS

The incidence of hyperthyroidism was 53% in surgically treated patients with nodular goitre in our iodine deficient region. The cause of thyrotoxicosis was toxic adenoma in 15 patients (14%). Suppressed serum TSH levels indicated the hyperthyroidism in all of 15 patients. Solitary solid adenoma was found by ultrasonographic examination, and solitary autonomous hot nodule by thyroid scintigraphy. Surgical treatment consisted of unilateral total lobectomy. It was the primary treatment in 13 patients. Two patients had surgery as secondary treatment after unsuccessful primary radioactive iodine application. The early postoperative clinical course of all patients was uneventful. Thirteen patients who had surgery as primary treatment had normal thyroid function postoperatively contrary to other two patients who became hypothyroid after having unsuccessful radioiodine therapy, and surgery as the secondary treatment.

CONCLUSIONS

The incidence of hyperthyroidism and toxic adenoma is high in our surgically treated patients with nodular goitre. The diagnosis of toxic adenoma is not difficult by serum TSH measurements, and ultrasound and nuclear imaging of the thyroid. Surgery is effective and safe, and the treatment of choice for patients with toxic adenoma in order to control radically the hyperthyroidism and to achieve the goal of providing the euthyroid status.

[Iodine status and its influence on thyroid structure and function in children and teenagers after the introduction of an iodine prophylaxis programme in the city of Szczecin]

PURPOSE

Studies conducted in the early 1990s revealed the spread of iodine deficiency and endemic goitre throughout Poland and contributed to the adoption of statutory table salt iodization in 1997. The present work was undertaken to assess the efficacy of the current model of iodine prophylaxis on the basis of goitre incidence, ioduria, thyreoglobulin serum concentration, and thyroid gland function in a randomly selected group of children residing in the city of Szczecin between 2002 and 2003.

MATERIAL AND METHODS

Subjects taking vitamin or mineral preparations enriched with iodine were excluded from the study. The study group included 273 children aged 9 to 16 years (140 boys (52%) and 133 girls (48%). Iodine excretion in urine was determined with the catalytic Sandell-Kolthoff reaction. Radioimmunometric and radioimmunological methods were used for the determination of thyreoglobulin (Tg), thyrotropin (TSH), and free thyroxine (FT4) concentrations. Goitre was confirmed in 12 children (4.3%).

RESULTS

In this subgroup, iodine excretion in urine was significantly lower (75.4 +/-35.66 microg/L vs. 86.1 +/- 44.2 microg/L in children without goitre) and thyreoglobulin serum concentration was higher (14.36 +/- 8.9 microg/L and 11.92 +/- 7.49 microg/L, respectively). The differences in TSH and FT4 concentrations were statistically insignificant. Mean iodine concentration in urine was 86.22 +/- 44.97 microg/L in the whole study group. Abnormal ioduria occurred in more than 65% of children. Mean FT4 concentration was 14.58 +/- 4.49 pmol/L and TSH was 2.16 +/- 1.08 microU/mL in the whole group. Mean thyreoglobulin concentration was 11.94 +/- 7.57 microg/L and was increased in 55% of children. There was a significant correlation of thyreoglobulin with FT4 (rs = -0.24) and thyrotropin (rs = 0.21) concentrations. No correlation was found between the concentration of these hormones and ioduria. Similarly, there was no correlation between thyreoglobulin concentration and iodine urinary excretion. This study revealed a partial efficacy of current model of iodine prophylaxis. One important result of the prophylaxis programme is a decrease in the incidence of goitre below endemic level.

CONCLUSION

Mean iodine concentrations in urine and thyreoglobulin serum concentrations demonstrate a state of iodine deficiency in Szczecin region. Correlations between thyreoglobulin concentrations, free thyroxine and thyrotropin suggest that Tg is a more useful indicator of iodine balance than ioduria.

Urinary iodine and other iodine deficiency indicators in a sample of school-age children in Egypt

Sufficient data relating urinary iodine excretion in children to other iodine deficiency indicators are lacking in Egypt. We assayed urinary iodine concentration and serum levels of thyroid stimulating hormone (TSH), thyroglobulin, free triiodothyronine (T3) and free tetraiodothyronine in 99 school-aged Egyptian children. Goitre was found in 25 children. Median urinary iodine concentration was 70 microg/L. We found mild iodine deficiency (50-99 microg/L) in 60.6 % of the children and moderate to severe deficiency (< 50 microg/L) in 31.3%. The latter showed a high frequency of goitre and elevated mean serum free T3, TSH and thyroglobulin levels. Individual urinary iodine excretion rates vary, therefore these other indicators could help in screening for iodine deficiency at an individual level, especially in moderate to severe deficiency.

Testing the association between thyroid dysfunction and psychiatric diagnostic group in an iodine-deficient area

OBJECTIVE

To test the association between thyroid dysfunction and psychiatric diagnostic group in a large sample of consecutive patients, while controlling for the effects of age, sex, medication and concomitant medical conditions.

METHODS

We compared the distribution of psychiatric diagnostic groups according to the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10), and of selected psychopathological symptoms in 100 newly admitted psychiatric patients who had genuine thyroid disease and 92 psychiatric patients who had nonspecific alterations of thyroid function with the corresponding items for the whole group of admitted patients (n = 1134) during the observation period. This analysis was then repeated using an age-matched and sex-matched comparison group selected from all admitted patients in a random order.

RESULTS

When all admitted patients were considered, the presence of a genuine thyroid disorder was associated with the diagnosis of a mood disorder (ICD-10 category F3). This effect was no longer detectable when the age-matched and sex-matched comparison group was used, indicating a simple effect of these 2 variables. Nonspecific alterations of thyroid-stimulating hormone (TSH) were associated with the ICD-10 diagnostic group F4 (neurotic, stress-related and somatoform disorders), with demographic variables being similar in this subgroup to those of all admitted patients. These patients also tended to display more symptoms of a mild depressive syndrome. When only patients with nonspecifically decreased TSH concentrations were tested, these findings could not be reproduced. Nonspecifically decreased concentrations of thyroxine and free thyroxine index were found significantly more often in the diagnosis group F1 (mental disorder due to substance use), reflecting results for alcohol-dependent patients. This result could not be replicated using an age-matched and sex-matched control group.

CONCLUSION

In newly admitted psychiatric patients with genuine thyroid disease, there was no notable association of thyroid disease and major psychiatric diagnostic groups according to ICD-10, especially depression. This argues against the hypothesis of thyroid disorders being a major risk factor for psychiatric illnesses. Nonspecific alterations of TSH were more frequently seen in patients of diagnostic group F4 and with mild depressive syndromes, possibly representing an altered influence of stress-regulating systems on thyroid function.

The relationship between iron status and thyroid hormones in adolescents living in an iodine deficient area

BACKGROUND

Iron may be only one of many nutritional factors that influence thyroid hormone metabolism in iodine-deficient areas.

OBJECTIVE

To evaluate the effect of iron status on thyroid hormone profile in adolescents living in a mild iodine-deficient area in Turkey.

SUBJECTS

Three hundred and thirty school-aged children with mean age 14 years were examined.

METHODS

Free triiodothyronine, free tetraiodothyronine and thyrotropin levels were analyzed by chemiluminescent enzyme immunoassay. Hemoglobin and mean corpuscular volume were measured with a Hemocounter. Iron and total iron binding capacity concentration were determined by colorimetric photometric methods. Ferritin level was determined by immunoturbidimetry.

RESULTS

Thyroid hormone levels of the children with anemia were not significantly different compared to children without anemia. No significant correlation was found between thyroid hormones and iron status.

CONCLUSION

The thyroid hormone profile was not significantly affected in this area. This survey showed no correlation between iron status and thyroid hormone levels.

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.

Iodine deficiency disorders in 15 districts of India

METHODS

A multicentre study to assess iodine deficiency disorders (goitre and deaf-mutism/cretinism) in 1, 45, 264 children (6 - <12 years old) from 15 districts of ten states was carried out during 1997-2000. Urinary iodine excretion was also determined in 27481 children, while iodine content was estimated in 5881 samples of edible salt. The sampling methodology followed was a "30 cluster survey".

RESULTS

The overall prevalence of goitre was 4.78% (4.66% of grade I and 0.12% of grade II) amongst the children examined. The highest prevalence of 31.02% goitre was observed in Dehradun district, while the lowest prevalence of 0.02% goitre was recorded in Bishnupur and Badaun districts. The overall prevalence of cretinism among children examined from seven districts was 0.072% whereas that of deaf-mutism was 0.27% among children examined from 8 districts. Median urinary iodine values was marginally less than the WHO cut-off values only in children of the 3 out of the 15 districts surveyed. Iodine content was found to be adequate in 55.45% of the salt samples.

CONCLUSION

The results suggested a significant decline in the prevalence of goitre in most parts of the country.

[Analytical problems of iodine defficiency examination in Polish Nation-wide deficit control program]

The environmental iodine deficiency has been a serious problem in the Polish health care system for many years. In many European countries the prevention of iodine deficiency-related health deficits in population scale is based on edible salt supplementation with KI. In the decade of the 80-ties the iodine supplementation program in Poland was stopped, which has caused a subsequent increase in prevalence of goiter and iodine deficiency-related hypothyreosis. These diseases were observed in many regions of Poland, including the areas beyond regions of formerly known iodine deficiency endemias. In order to control the whole Polish population, iodine consumption deficit in1991 the "Polish Program of Iodine Deficiency Control and Prevention of Iodine Deficiency-related Disorders" has been established in the year 1991. In 1992--1996 a common iodine supplementation of salt used for general consumption was 20 mg KI/kg of NaCl, and in 1997 the mandatory supplementation of salt was 30 (+10) per kg of salt which has been introduced for the whole country. This paper reports the results of iodine excretion assays in school children 6-12 years old, in the years 1993--94, 1996--97 and 1999--2002 respectively. The obtained collections of iodine urine concentrations have shown distributions with a remarkable rightward skewness. Normalization of distributions required logarythmic transformation. The quartile values obtained for data collections from years 1992--94, 1996--97 and 1999--2002 have shown that in 5-7 years of iodine deficiency prevention program yielded increase in iodine excretion in morning urine samples by about 37.8 microg, while the iodine excretion median values increased from 63.5 mg/L in years 1992--1994 to 94.0 mg/L in years 1999--2001, respectively. The lower limits of iodine excretion ranges calculated as the mean value minus 2SD of transformed data for the years 1992--1994 amounted to: 7.74 mg/L and for the years 1999--2001 amounted to 14.1 microg/l, respectively. Assessing percent of children obtaining low iodine suplementation then recommended (below 50 mg/L in urine sample) amounted to 35.8% in years 1992--1994 and 15.4% in years 1999--2001 respectively.

[Comparative analysis of the efficacy of iodine prophylaxis in pregnant women living in endemic goiter areas]

AIM

To assess efficacy of different methods of iodine prophylaxis in pregnant women living in conditions of goiter endemia.

MATERIAL AND METHODS

Standard clinical, laboratory and device tests for iodine deficiency according to WHO criteria were made in 156 pregnant women living in the territory affected by goiter endemia. Of them, 121 examinees had no thyroid pathology, 35 ones had diffuse euthyroid goiter. All of them received different kinds of iodine prophylaxis.

RESULTS

The occurrence of neonatal TTH values over 5 iU/l in neonates born by mothers free of thyroid pathology on potassium iodide prophylaxis when pregnant was 9.1%. This is much lower than in conventional iodine prophylaxis--17.24% (p < 0.01). A comparative analysis of the efficacy of potassium iodide-200 in pregnant women with diffuse euthyroid goiter and its combination with L-thyroxine has shown that by the effect on lessening frequency of neonatal TTH over 5 iU/l the above schemes do not differ significantly, thyroid reduction is more prominent in pregnant women on thyroxine with potassium iodide.

CONCLUSION

The index of neonatal TTH is an objective criterium to control efficacy of different methods of iodine prophylaxis in pregnancy.

[Preoperative assessment of thyroid nodules in an endemic goiter region--possibilities and limitations]

In iodine-sufficient areas any thyroid nodule has to be regarded as potentially malignant, whereas in iodine-deficient areas (endemic goiter areas) thyroid nodules, even multinodular goiter, are frequent. The majority of thyroid nodules in an endemic goiter area can be regarded as being most likely benign and thus not all patients with multinodular goiter have to undergo surgery. The major diagnostic aim and challenge is the selection for surgery of only those patients who suffer from mechanical obstruction due to large goiter and those who present with nodules suspicious of malignancy. Thus, for these cases the question of accurately excluding or verifying malignancy is essential for the patient and the specialist of nuclear medicine or endocrinology. A variety of investigations may be used for the preoperative evaluation of thyroid nodules, although currently sonography and fine-needle biopsy have to be regarded as the key investigations to clarify preoperatively the dignity of thyroid nodules. The article presents the indications and limitations of the different methods in use for the evaluation of thyroid malignancy. The authors present a diagnostic algorithm for the preoperative evaluation of thyroid malignancy with special respect to problems occurring in a(n) (former) endemic goiter area.

Thyroid function test abnormalities in newly admitted psychiatric patients residing in an iodine-deficient area: patterns and clinical significance

OBJECTIVE

The prevalence of abnormal in-vitro thyroid function tests in psychiatric in-patients may be as high as 24%. Thus far, however, there is only limited data addressing the underlying causes of these abnormal test results, i.e. how often they can be attributed to genuine thyroid disease.

METHOD

We conducted an observational study of all in-patients admitted to our institution during 1 calendar year running analyses of total thyroxin (T4), free thyroxin index (FTI) and thyroid-stimulating hormone (TSH). Patients with abnormal test results were classified according to an algorithm which had been established previously.

RESULTS

In 243 of 880 patients with in-vitro thyroid function analysis, at least one concentration of either T4, FTI or TSH was found to be outside the reference range. Work-up according to the algorithm was completed in 848 patients; alterations were classified as representing thyroid dysfunction in 100 (41% of patients with abnormal test results), non-specific findings in 92 (38%), influence of ingested drugs in 18 (7%) and of severe physical disease in 1 (0.4%). As measures of T4 and/or FTI provided no essential information in 854 patients (97% of tested), we found that in most cases the determination of TSH alone was sufficient for demonstrating normal thyroid function.

CONCLUSION

In 27.6% of newly admitted patients living in an iodine-deficient area, at least one abnormal result in either T4, FTI or TSH values was found. Genuine thyroid disease was found in slightly less than half the patients with an abnormal value.

Moderate to severe iodine deficiency in three endemic goitre areas from the Black Sea region and the capital of Turkey

Endemic goitre is still an important and underestimated health concern in Turkey. The overall prevalence had been calculated as 30.3% by palpation in a national survey conducted in 1995. However, direct evidence that iodine deficiency (ID) is the major cause of the endemic were lacking until now. We measured sonographic thyroid volumes (STV), urinary iodine concentrations (UIC) in 1226 school age children (SAC) (9-11 year old) from Ankara the capital of Turkey located in the central Anatolia, and three highly endemic goitre areas of the Black Sea region. A considerable number of school age children (SAC) were found to have STV exceeding the recommended upper normal limits for their age and gender obtained from iodine-replete European children (i.e. 26.7, 40.3, 44.8 and 51.7% of children from Ankara, Kastamonu, Bayburt and Trabzon respectively). UIC indicated moderate to severe ID in these areas with median concentrations of 25.5, 30.5, 16.0 and 14 microg/L respectively. This study showed severe to moderate ID as the primary etiological factor for the goitre endemic observed in Ankara and the Black Sea region of Turkey.

National study on the prevalence of iodine deficiency disorders among schoolchildren 8-12 years of age in Bahrain

A cross-sectional survey of primary-school children in Bahrain was conducted to estimate the prevalence of goitre and iodine deficiency according to age, sex and area of residence. During January-May 1999, 1600 children were randomly chosen from all government schools. Children were examined for goitre and of those, 50% were randomly selected for urinary iodine level assessment. Only 26 children (1.7%) had goitre. Although median urinary iodine was above 100 microg/L, 121 of 749 children (16.2%) had low urinary iodine levels. Although iodine deficiency does not pose a significant public health problem in Bahrain, education about the nutritional value of iodized salts in the prevention of this disorder could increase public awareness.

Biochemical assessment of iodine deficiency disorders in Baroda and Dang districts of Gujarat State

OBJECTIVE

(i) To assess the severity of Iodine Deficiency Disorders (DD) in Baroda and Dang Districts of Gujarat, using biochemical prevalence indicators of IDD; and (ii) To establish a biochemical baseline, in a sub-sample of the large population of Gujarat, that could be used to monitor the effectiveness of iodine replacement program.

METHODS

1,363 children (<1-15 years) were studied and data was collected on dietary habits, anthropometric and biochemical parameters such as height, weight and urinary iodine (UI) and blood TSH respectively. BSA and BMI were calculated. Drinking water and salt were analyzed for iodine content.

RESULTS

Median true urinary iodine was 65 microg/I (interquartile-range 38-108). Mean TSH was 2.08 mU/1 (SD +/- 2.06) and 6% of the studied population had whole blood TSH values > 5 mU/1. Females from both districts were affected more by iodine deficiency as evidenced by lower true urinary iodine and higher mean TSH levels. The interfering substances were significantly higher in Baroda boys and Dang girls as compared to their counterparts (< 0.001). Boys were more malnourished than girls as evidenced by lower BMI. Dang district was more severely affected by IDD as compared to Baroda. Drinking water in Dang district was lacking in iodine content. Iodine in salt varied at around 7 to 2000 PPM.

CONCLUSIONS

IDD is a public health problem in Gujarat. Baroda district is a new pocket of IDD. Dang district is the worse affected. The expression of IDD in these two districts of Gujarat revealed interplay of multiple factors.

Changes in serum thyroid hormone levels in newborn calves as a diagnostic index of endemic goiter

Maximum serum thyroxine (T4) and triiodothyronine (T3) levels of healthy calves were seen at 1 day after birth, and thereafter rapidly decreased until 5 days after birth. They stabilized until 2 weeks after birth, then gradually decreased until 4 weeks after birth. Serum T4 levels of calves with endemic goiter tended to be lower than those of healthy ones, but showed similar levels to those of adult cows. T3 levels of calves with goiter were similar to those of healthy ones, but showed higher variation. T4/T3 ratio of calves with goiter were significantly lower than those of healthy ones and adult cows. While individual levels of serum T4 and T3 at just after birth could not be considered as a diagnostic index, the T4/T3 ratio could be adopted as a diagnostic index of endemic goiter.

Assessment of iodine deficiency disorders using the 30 cluster approach in district Kangra, Himachal Pradesh, India

Iodine deficiency is an important public health problem in Himachal Pradesh. District Kangra is a known iodine deficiency endemic area. A survey conducted in 1956 reported a goitre prevalence of 55 per cent in the district. A more recent pilot study (1994) in four blocks of the district reported the total goitre rate (TGR) as 7 per cent. A continued prevalence of goitre in more than 5 per cent of school-aged children was found in pilot study, in spite of the distribution of iodised salt. The present study was conducted to assess the prevalence of iodine deficiency disorders (IDD) and to estimate the iodine content of salt consumed by the population in district Kangra. The '30 cluster' sampling methodology and indicators for assessment of IDD, as recommended by the joint WHO/UNICEF/ICCIDD consultation, were utilized for the survey. A confidence level of 95 per cent, a relative precision of 10 per cent and a design effect of three were taken into account for calculation of the sample size. A total of 23,348 school children in the age group 6-11 years were included in the study. The total goitre prevalence rate was found to be 12.1 per cent. The median urinary iodine excretion of the children studied was found to the 15.00 mcg/dl. About 12.7 per cent of families consumed salt with an iodine content of less than 15 ppm. The results of the present study indicated that the population of district Kangra is in a transition phase from iodine deficient to iodine sufficient nutrition and that there is a need for further strengthening of the system of monitoring the quality of iodised salt made available to the population to eliminate IDD from the Kangra Valley.

Iodine status of children and use of iodized salt in Tarai region of North India

A study was planned to investigate the iodine status of children 10-12 years old and the use of iodized salt. Goitre prevalence was estimated in 770 children between the ages of 10-12 years. The overall prevalence was 38.18 per cent. Urinary iodine excretion was also estimated in morning samples. A total of 41.43 per cent children suffered from iodine deficiency disorder (IDD) in the Tarai area. To obtain the iodine intake, salt samples from the children's families were collected and analysed for iodine content. Salt samples having 15 ppm or more of iodine were 95.53 per cent while 1.69 per cent samples were totally devoid of iodine content. It can be concluded that in spite of adequate availability and consumption of iodized salt, IDD still exists and is endemic in the region.

Goitre prevalence and thyroid abnormalities at ultrasonography: a comparative epidemiological study in two regions with slightly different iodine status

OBJECTIVE

The association between severe iodine deficiency and endemic goitre is well established, but little information is available on the relation between milder degrees of iodine deficiency and goitre prevalence.

SUBJECTS

In a comparative epidemiological study performed in two regions in Denmark, we examined 4649 subjects from the general population, women aged 18-65 years and men aged 60-65 years.

METHODS

Ultrasonography and palpation of the thyroid was performed in all participants. Iodine excretion was measured in casual urine samples. Previous thyroid disease was detected by questionnaires, personal interviews and tracing of records.

RESULTS

The median iodine excretion was 61 microg/l (mild iodine deficiency (ID)) and 45 microg/l (moderate ID) in the two regions. Median thyroid volume at ultrasonography was 11. 9 ml (mild ID) and 13.6 ml (moderate ID), P <0.001, and thyroid enlargement was found in 15.0% (mild ID) and 22.6% (moderate ID), P<0.001. Goitre prevalence increased in both regions with age to the age group 40-45 years, but not after that age. Subjects who had moved from the moderate ID to the mild ID area had the same prevalence of thyroid enlargement as the subjects staying permanently in the mild ID area. Thyroid nodules at ultrasonography were found in 30% in both regions, but nodules were larger and more often palpable in the moderate ID area. Palpable goitre was found in 9.8% (mild ID) and 14.6% (moderate ID), P<0.001. The greatest regional difference in thyroid abnormalities was found among men.

CONCLUSION

Marked differences in the prevalence of thyroid abnormalities were found in these regions with modest differences in iodine excretion.

[Diagnosis and therapy of patients with euthyroid goiter]

Nontoxic goitre is common, even in areas where iodine intake is sufficient. The most important symptoms and signs of nontoxic goitre are caused by compression of vital structures in the neck or upper thoracic cavity. In any patient with goitre the serum concentration of thyroid-stimulating hormone (TSH) should be measured to detect or exclude clinically inapparent (subclinical) hyper- or hypothyroidism. CT and MRI are expensive but very sensitive methods to identify tracheal compression and to determine intrathoracic extension. Thyroid ultrasonography and scintigraphy are not routinely indicated. Fine-needle aspiration biopsy is indicated in patients with fast-growing nodules and nodules that have a firmer consistency than other nodules within the gland. Thyroidectomy is standard therapy for young and otherwise healthy patients, especially when prompt decompression of vital structures is required. Radioiodine therapy is an attractive alternative to surgery in older patients, in those with cardiopulmonary disease, and in those with recurrent goitre. Thyroxin therapy may be tried in young patients with small, diffuse goitres who have normal serum TSH concentrations.

Assessment of goiter in an area of endemic iodine deficiency

Urinary iodone (UI) excretion and sonographically measured thyroid volume were investigated in 195 subjects living in 6 separate villages in the Casamance region of southeastern Senegal, West Africa. A comparison of goiter prevalence using thyroid palpation and volume measurement and of iodine excretion expressed as micrograms per gram (microg/g) creatinine or micrograms per deciliter (microg/dl) urine was undertaken, and possible pathogenetic factors were investigated. Ultrasound measured thyroid volumes were above the recommended upper limit of the reference range for an area replete in iodine in 83.1% or females, 52.3% of males, and 80.0% of children aged 13 years or younger. Overall sensitivity and specificity for palpation compared to sonographically demonstrated thyroid enlargement was 51.7% and 91.5%, respectively. Thyroid enlargement was not associated with ethnic origin, thiocyanate ingestion, HLA DR/DQ phenotype frequency, or thyroid growth-stimulating immunoglobulin (TGI) positivity. Median UI was 32 microg/g creatinine with 65.0% having values consistent with iodine deficiency (< 50 microg/g). When results were expressed as micrograms per deciliter, the percentage having values consistent with iodine deficiency (< 5.0 microg/dl) increased to 95.7%. The findings suggest a primary role for iodine deficiency in goitrogenesis in the study population. They demonstrate that classification of the severity of the endemia in this or other study populations in areas of iodine deficiency is dependent on the methods used to determine goiter prevalence (palpation or ultrasound measured thyroid enlargement), or dietary iodine status (iodine excretion expressed as micrograms per gram creatinine or micrograms per deciliter urine).

Urinary iodine excretion as a predictor of the iodine content of breast milk

Endemic goitre has re-emerged in Thailand. This is particularly dangerous for children since iodine deficiency disorders (IDDs) might negatively influence their intellectual and mental development. In order to assess the situation, the iodine content of breast milk was determined and a method is proposed on how to monitor IDDs in lactating mothers later on. Seventy-five lactating women aged from 15 to 45 years, from 12 villages of 3 districts, namely Chumpae. Srichompu and Pupaman within the mountainous areas of Khon Kaen province, Northeast of Thailand were investigated. The breast milk from 46.7 per cent of mothers was found to be below recommended standards. In addition, 52.0 per cent of the women investigated had low urinary iodine excretion. The risk of women with low iodine excretion was 15 fold higher in comparison to women with sufficient iodine excretion to provide breast milk for their babies with insufficient iodine content. It is concluded that urinary iodine excretion can be used to monitor the IDDs in lactating mothers.

[Epidemiology of iodine deficiency in the middle Ob regions]

AIM

Epidemiological rvaluation of goiter endemia and iodine deficiency in population of the Middle Ob region.

MATERIALS AND METHODS

Thyroid palpation and ultrasonic investigations, iodine measurements in the urine were made in 6256 children and adolescents aged 8-17 years.

RESULTS

Euthyroid condition was clinically stated in all the examinees. Palpation discovered thyroid enlargement in 36.78% of the examinees. Age prevalence was: 27.3, 33.28, 42.8, 46.18% in children and adolescents aged 8-10, 11-12, 13-14 and 15-17 years, respectively. Ultrasound detected goiter in 30.6% of the examinees. The occurrence was 34.78, 31.68, 28.2, 19.8% in the above age groups, respectively. No significant differences by thyroid size existed in girls versus boys. Urinary iodine was low in all the age groups.

CONCLUSION

The Middle Ob regions belong to zone of goiter endemia with mild to moderate iodine deficiency. This dictates the necessity of introduction of special programs of iodine deficiency control and prevention.

[Current situation of goiter endemic and iodine intake in the population of the Pyrenees and the Segrià region of Lleida]

OBJECTIVE

To assess the prevalence of goiter in five areas of the Pyrineans and in the region of Segrià in Lleida.

DESIGN

Transversal descriptive study.

SETTING

Five Pyrinean's regions and Segrià.

PATIENTS

Randomised selection of a sample of 601 subjects from the population over 6 years old.

MEASUREMENTS

The field work, which was preceded by an informative campaign in the media, was carried out from October of 1994 through February of 1995. Survey with a personal interview, blood pressure, weight, height, goiter palpation, blood analysis with thyroidal hormones and urine analysis with the iodine/creatine ratio determination.

RESULTS

The prevalence of goiter was 18.3% which was higher among women, the ratio being 3.7/1 (women/men). No significant differences were found in regard to geographic distribution. Mean iodinuria was 120 micrograms/l, though it was below 50 in 11.1% subjects. The prevalence of goiter has been founded to be related to age, increasing from the age of 45 onwards. Higher percentage of goiter was found among individuals with a family history of the disease and women who have had children. The prevalence of hypothyroidism was 3.4%.

CONCLUSIONS

We have found a medium degree of goiter's endemia in the study area, the mean iodinuria in the population is in normal range. The women with children have a higher prevalence of goiter probably due to a lack of sufficient iodine intake being a subgroup at risk.

Investigations of thyroid diseases--an update on diagnostic methods

Iodine deficiency disorders (IDD) are an important public health problem in India. It requires further refinement and improvements in thyroid disease diagnosis, especially in the early diagnosis of thyroid malfunctioning and risk assessment of autonomously functioning thyroid tissue. Scintigraphy with technetium-99m pertechnetate under exogenous or endogenous thyroid stimulating hormone (TSH) suppression provides the best results. There has been significant improvement in methodology in various laboratory investigations that have resulted from the application of newer luminescent techniques and gene technology in various thyroid function tests. TSH measurement especially by using second or third generation assays has ensured diagnostic accuracy and thyrotropin releasing hormone (TRH) test now almost always unnecessary. Determination of glycosaminoglycans in urine may become a helpful tool in the follow up of endocrine ophthalmopathy. The differentiation of blocking and stimulating TSH receptor antibodies is relevant when discrepant results are obtained with respect to thyroid function. Some newer imaging agents have been used in thyroid disease scintigraphy such as octreotide or in thyroid diseases diagnosis such as fluorodeoxyglucose. Both improve the detectability of thyroid cancer metastasis especially if radioiodine scan is negative.