[Hygienic characteristics of the population's morbidity rate associated with iodine deficiency in the Republic of Mordovia].

In the article there are presented the results of research on naturally conditioned insufficiency of trace elements, particularly iodine, in the Republic of Mordovia. Iodine deficiency disorders are referred to the most common non-infectious human pathology. According to WHO data, about two billion people on Earth live in conditions of in iodine deficiency. In the Russian Federation there are no areas in which the population would not be at risk for the development of iodine deficiency disorders. To these regions and the Republic of Mordovia is referred. The prevalence of diseases caused by iodine deficiency among the urban population accounted for 100-150, among rural--130-350. In some regions of endemic goiter rate reaches 800. Analysis of the morbidity rate of the population in the Republic of Mordovia, associated with the iodine deficiency, shows that in the structure of diseases related to micronutrient deficiency, by 2013 diffuse goiter plays a leading role, beingfollowed by a multi-node (endemic) goiter onward thyroiditis, subclinical hypothyroidism and hyperthyroidism. Thus, the analysis of indices of new cases of diseases associated with the iodine deficiency, allows to make the conclusion that diffuse goiter is the most significant pathology. In the structure of diseases related to the micronutrient deficiency, out of the most frequently detected iodine deficiency disorders, the greatest fraction are diffuse and multinodular goiter. The study was conducted with the support of the project, performed in the framework of the basic part of the State assignment (project 2859) and a RHSF grant.

[Thyroid functional activity and hemodynamic parameters in upper-class schoolchildren presenting with endemic goiter].

We studied the relationship between iodine deficiency, blood cortisol levels, andhemodynamicparameters in 536schoolchildren of Vladikavkaz aged 13-17 years. Urine iodine was measured using cerium arsenite reaction, thyroid function was evaluated from thyrotropin, T3, and free T4 levels, blood cortisol was determined by the immonoenzyme assay using Alcor Bio kits. The study group included 24 subjects with endemic goiter, control group was comprised of 14 healthy adolescents. Hemodynamic parameters were studied using a Vivid 7 Dimension scanner.

Excessive iodine intake, water chemicals and endemic goitre in a Sudanese coastal area.

OBJECTIVE: To study the associations between intakes of iodine and water chemicals and the thyroid gland status of schoolchildren living in the coastal city of Port Sudan. DESIGN: In our previous nationwide study on goitre, it was observed that the prevalence of goitre was high in Port Sudan city despite high urinary iodine excretion. A cross-sectional study including schoolchildren aged 6­12 years was designed. Measurements determined the prevalence of goitre, urinary iodine concentration and thiocyanate secretion in casual urine samples, serum levels of thyroxine, triiodothyronine, thyroid-stimulating hormone and thyroglobulin, as well as the levels of Cl⁻, F⁻, Ca²âº, Mg²âº and total hardness of drinking water. SUBJECTS: Schoolchildren (n 654) aged 6­12 years. SETTING: Port Sudan city is located at the western bank of the Red Sea. The city is surrounded by a mountainous area known as the Red Sea Hills. It is the main sea port in the Sudan, inhabited by ethnically and socio-economically heterogeneous populations. RESULTS: The prevalence of goitre in Port Sudan was 34.86% while the median urinary iodine concentration was 46,4µg/dl. Out of thirty-one pupils from Port Sudan, twenty-four (77.42 %) were found to have urinary iodine concentration greater than 30µg/dl and twelve (38.71 %) had different degrees of biochemical hypothyroidism. Excessive concentrations of Cl⁻, Ca²âº, Mg²âº and water hardness (369.2, 116.48, 60.21 and 539.0mg/l, respectively) were detected in drinking water samples collected from Port Sudan that exceeded levels permitted by the WHO. CONCLUSIONS: The coastal city of Port Sudan is a goitre-endemic area. In contrast to other Sudanese cities in which endemic goitre is related to iodine deficiency, goitre in Port Sudan is associated with iodine excess. Water chemicals seemed to have no effects on thyroid status.

Thyroid status two decades after salt iodization: country-wide data in school children from India.

OBJECTIVE: Country-wide evaluation of thyroid disorders in school children following two decades of universal salt iodization (USI) has not been carried out till date. This study was planned with aim to assess thyroid status of school children two decades after the launch of USI programme. DESIGN: Population survey. PATIENTS: We collected data from 25 schools in 19 cities across five different geographical zones of India. Those children who were evaluated for anthropometry, and goitre status by palpation formed 'total population'. Children who consented to give blood samples were defined as 'study population'. MEASUREMENTS: Serum free T3, free T4, TSH, anti-TPO antibody and thyroid ultrasound. RESULTS: A total of 38,961 children aged 5-15 years formed total population. Goitre rate was 15.5% while thyroid hypoechogenicity was found in 4404 (11.3%) children. In the study population (13,790 children), 2258 (16.4%) had goitre, 505 (3.7%) had positive anti-TPO antibody titres, 1001 (7.3%) had hypothyroidism (TSH > 5.2 µIU/ml) and 41 (0.3%) had thyrotoxicosis (TSH < 0.1 µIU/ml). Among goitrous children, 203 (9.0%) had anti-TPO positivity, 365 (16.1%) had hypoechogenicity of thyroid and either of these were present in 488 (21.6%) children. CONCLUSIONS: Endemic goitre in school children persisted nationwide, despite more than two decades of USI programme. Thyroid autoimmunity only partially explains the increase in goitre prevalence.

[Interleukin-6 in endemic goiter patients in the south Ural region].

The cytokine and thyroid status was studied in patients with endemic goiter (EG) depending on thyroid function. IL-6 correlated with free T3 levels (a negative relationship) in hyperthyroidism, with IL-2 and IFN-gamma levels in EG patients with euthyroidism, and with IL-1beta, IL-2, IL-8, IL-10, and IFN-gamma in hypothyroidism. The EG patients with high IL-6 levels showed positive relationships to IL-2 and thyroid peroxidase antibodies and a negative relationship to free T3. In these patients, IL-6 acted to stimulate the secretion of antithyroid antibodies, which is a risk of autoimmune thyroiditis.

Seasons but not ethnicity influence urinary iodine concentrations in Belgian adults.

BACKGROUND: Mild iodine deficiency (MID) is endemic in Belgium. Previous surveys, which assessed iodine nutrition in Belgium, focused on children. The iodine status of adults and the influence of ethnicity or seasonality on urinary iodine concentrations (UIC) have not been investigated. Since the nutritional profile of children differs from that of adults, we may anticipate similar differences in iodine status. Seasonal fluctuations in UIC have also been reported from other MID regions. AIM OF THE STUDY: We aimed at assessing iodine status and its association with ethnicity and seasonality in adults. METHODS: A stratified random sample of 401 healthy subjects aged between 40 and 60 years, of Belgian, Moroccan, Turkish and Congolese descent residing in Brussels was obtained. Iodine status and thyroid function were determined. RESULTS: Median UIC was 68 µg/L. The frequency of UIC below 100 µg/L was 73.3%, of which 41.9% fell between 50 and 99 µg/L, and 29.8% between 49 and 20 µg/L. There was no difference in UIC and thyroid function between subjects of different ethnic origins. The frequency of UIC below 50 µg/L was higher in the fall-winter compared to spring-summer periods (P = 0.004). Serum FT3 concentrations, but not FT4 and TSH, were significantly greater in winter than in summer. CONCLUSION: Seasonal fluctuations in UIC suggest that the risk of iodine deficiency among adults living in Brussels is higher in fall-winter than in spring-summer. The prevalence of MID in Brussels is high among adults but ethnicity does not appear to influence iodine status.

Prevalence of goitre in Isfahan, Iran, fifteen years after initiation of universal salt iodization.

This cross-sectional study investigated the prevalence of goitre in Isfahan, a centrally-located city in Iran, 15 years after the initiation of universal salt iodization. In total, 2,523 Isfahani adults (1,275 males, 1,248 females) aged > 20 years were selected by multi-stage cluster-sampling method. Goitre rate, serum thyroid-stimulating hormone (TSH), thyroxine (T4), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), and urinary iodine concentration (UIC) were measured and compared between the goitrous (n = 478) and the non-goitrous (n = 2,045) participants. The total goitre rate was 19% (n = 478) of the 2,523 adults. The rate of Grade I and II goitre was 12.4% (n = 312) and 6.6% (n = 166) respectively. The total goitre rate, Grade I and II goitre were more prevalent among women than among men. Hypothyroidism was observed in 6.4% (130/2,045) and 18.6% (89/478) of the non-goitrous and goitrous participants respectively [odds ratio (OR) = 3.6, 95% confidence interval (CI) 2.7-4.9, p = 0.001]. Hyperthyroidism was present in 0.8% (17/2,045) and 5.2% (29/478) of the non-goitrous and goitrous adults respectively (OR = 9.0, 95% CI 4.9-16.6, p = 0.001). Hypothyroidism was more prevalent in Grade II than in Grade I goitre and among those without goitre (31.3%, 14.1%, and 6.4% respectively) (p = 0.001). Positive TPOAb was observed in 24% (n = 50) of the non-goitrous and 33.5% (n = 84) of the goitrous subjects (p = 0.03). Positive TPOAb was observed in 24.6% (35 of 142) of the Grade I and 45% (49 of 109) of the Grade II goitrous adults (p = 0.001). Positive TgAb was observed in 21.6% (n = 45) of the non-goitrous and 35.9% (n = 90) of the goitrous adults (p = 0.001). Positive TgAb was observed in 30.3% (43 of 142) of the Grade I and 43.1% (47 of 109) of the Grade II goitrous adults (p = 0.04). The median UIC was 18 microg/dL (range 1-80 microg/dL). It was 17.9 microg/dL and 19 microg/dL in the non-goitrous and goitrous adults respectively. After 15 years of successful universal salt iodization in Isfahan, goitre is still endemic, which may be due to thyroid autoimmunity. However, other environmental or genetic factors may have a role.

[Blood levels of trace elements in urban children with diffuse non-toxic goiter].

The blood concentrations of cadmium, cobalt, lead, manganese, copper, and zinc were studied in Vladivostok schoolchildren with diffuse non-toxic goiter followed up by an endocrinologist for 2-5years. It was established that the content of cadmium, cobalt, lead, and manganese significantly exceeded the relevant values in healthy adolescents and that of copper was lower. Zinc levels did not differ from those in healthy individuals.

Circulating immonoglobulin M: increased concentrations in endemic and sporadic goiter.

Increased concentrations of immunoglobulin M have been found in the circulation of approximately half of patients with either endemic or sporadic nontoxic goiter. Blood was obtained from patients in several iodine-deficient goitrous areas; the patients with sporadic goiter resided in or about New York City. Concentrations of immunoglobulins G, A, and D were normal. Blood for control purposes was taken from patients residing in cities near the goiter areas where there was no iodine deficiency, and in New York City. Most of these samples came from hospitalized patients without known thyroid disease and were collected at random. Chi-square values for the difference between the number of goitrous patients with elevated concentrations of immunoglobulin M and those in the control patients were highly significant statistically.

Iodine status in a Sherpa community in a village of the Khumbu region of Nepal.

OBJECTIVE: To assess the iodine status of Sherpa residents living in Kunde village, Khumbu region, Nepal. DESIGN: Prevalence of goitre was determined by palpation. Urinary iodine concentrations (UIC) were determined in casual morning samples, and thyroid-stimulating hormone (TSH) in finger-prick blood samples on filter paper. Dietary and demographic data were obtained via questionnaire, and selected foods analysed for iodine. SETTING: Khumbu region is an area of low soil iodine in Nepal, where the prevalence of goitre was greater than 90% in the 1960s prior to iodine intervention. SUBJECTS: Two hundred and fifteen of 219 permanent residents of Kunde were studied. RESULTS: Overall prevalence of goitre was 31% (Grade 1 goitre, 27.0%; Grade 2, 4.2%). When adjusted to a world population, goitre prevalence was 27% (95% CI 23, 32%); Grade 2 goitre prevalence was 2.8% (95% CI 1.0, 4.6%). Median UIC was 97 microg/l, but only 75 microg/l in women of childbearing age. Thirty per cent had UIC < 50 microg/l and 52% had UIC < 100 microg/l, while 31% of children aged <14 years had UIC > 300 microg/l. Ten per cent of participants had TSH concentrations >5 microU/ml. CONCLUSIONS: The prevalence of severe iodine deficiency has decreased since the 1960s, but mild iodine deficiency persists, particularly in women of childbearing age. The consumption of high-iodine uncooked instant noodles and flavour sachets by school-aged children contributed to their low prevalence of goitre and excessive UIC values. This finding may obscure a more severe iodine deficiency in the population, while increasing the risk of iodine-induced hyperthyroidism in children. Ongoing monitoring is essential.

Vitamin A status does not contribute to the residual goiter in schoolchildren of Isfahan, an iodine replenished area.

Two thousand three hundred and thirty-one schoolchildren were selected by multi-stage random sampling. The thyroid size was estimated by inspection and palpation. The urinary iodine concentration and serum retinol (SR) were measured in 454 and 468 schoolchildren, respectively. Overall, 32.9% of 2,331 children had goiter. The median urinary iodine concentration was 195.5 microg/l. The mean+/-standard deviation of SR in goitrous and non-goitrous children was 34.84+/-7.28 microg/dl and 33.73+/-7.87 microg/dl, respectively (P=0.14). There was no child with vitamin A deficiency (SR <20 microg/dl) in both the goitrous and non-goitrous groups. The prevalence of subjects with low vitamin A status (SR <30 microg/dl) in the goitrous and non-goitrous groups was 27.7% and 33.3%, respectively (P=0.21). In conclusion, the present study reveals that vitamin A deficiency and low vitamin A status are not among the contributing factors of goiter persistence in the studied area, and the role of other responsible factors should be investigated.

Thyroid autoantibodies in women with and without thyroid disorders in an iodine-replete area.

To compare the prevalence of positive autoantibodies in patients with thyroid disorders and healthy subjects in an iodine-replete area of the Islamic Republic of Iran, we studied 930 women in a clinic-based study: 698 patients (286 hypothyroid, 140 hyperthyroid, 272 with simple goitre) and 232 healthy women. Serum thyroxine (T4), triiodothyronine (T3), thyroid stimulating hormone, and anti-thyroid antibodies were measured. Positive autoantibodies were detected in 75.5% of patients with hypothyroidism, 73.6% of those with hyperthyroidism, 48.9% of those with simple goitre and 35.8% of the control group (P < 0.001). Autoimmunity may have a role in the genesis of common thyroid disorders.

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.

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.

Serum thyroglobulin in inhabitants of an endemic goiter region of New Guinea.

Serum thyroglobulin Tg(RIA) was studied in 161 residents of the Nomane region of New Guinea. The incidence of antithyroglobulin antibodies (ATA) and antimicrosomal antibodies (anti-M) was also studied to assess the role of autoimmunity in goitrogenesis. ATA were detected in only 4 sera; these sera were excluded from the study since ATA interfere in the Tg radioimmunoassay. Anti-M antibodies were undetectable in all of 105 subjects whose sera were analyzed. Mean (+/-se) serum Tg(RIA) in the 84 nongoitrous (NG) subjects was 163.1 +/- 17.2 ng/ml, whereas that in 77 goitrous (G) subjects was 208.1 +/- 19.8 ng/ml; both values were much higher (P is less than 0.001) than that (5.1 +/- 0.49 ng/ml) in normal Californian subjects. The mean serum thyroid stimulating hormone (TSH) in the NG group (12.1 +/- 2.1 muU/ml) was not statistically different from that in the G group (10.1 +/- 1.5 muU/ml). Serum Tg(RIA) correlated positively with log TSH (r equals 0.38 P is less than 0.001). Intrigued by the finding of goiters in some residents of an endemic goiter region and its absence in other residents exposed to the same environmental factors, we evaluated the possibility that the thyroid glands of subjects who develop goiters may be inherently more responsive to any given level of TSH than those of the inhabitants without goiters. However, the slope of the correlation between serum Tg(RIA) and log TSH was only slightly (0.1 is less than P is greater than .05) higher in G than in the NG group. These studies suggested that factors other than thyroidal responsiveness to TSH must also be important in goiterogenesis of endemic goiter regions. We conclude that 1) serum thyroglobulin is a sensitive parameter of chronic as well as acute thyroidal stimulation; 2) Thyroid autoimmunity and increased thyroidal response to TSH do not explain goiterogenesis in New Guinea and attention should be focused on other possibilities.

Increased serum thyroglobulin levels in patients with nontoxic goiter.

Thyroglobulin (Tg) levels were found to be elevated in 30 to 35 patients with euthyroid sporadic goiter and in 15 of 37 patients with euthyroid endemic goiter. The elevated Tg levels in the goitrous patients did not correlate with either goiter size, TSH levels, or urinary iodine excretion, but did correlate with the triiodothyronine to thyroxine ratio. It was concluded, therefore, that in both sporadic and endemic euthyroid goiters, factors other than goiter size and TSH, such as hypoiodination of Tg may be responsible for the elevated Tg secretion.

3,3',5'-triiodothyronine, thyroxine, triiodothyronine, and thyrotropin levels in maternal and cord blood sera from endemic goiter regions of Brazil.

T4, T3, rT3, and TSH were measured in cord blood of infants born in mild to severe endemic goiter areas and nonendemic urban areas in South and North America. A significantly high rT3 concentration was found in newborns living in the urban area of South America as compared to a Canadian newborn population. There were no differences among the various thyroid parameters in the groups of newborns studied. Blood from goitrous mothers showed significantly higher concentrations of T3 and TSH than nongoitrous mothers. However, these changes did not affect the concentrations of thyroid hormones, rT3, or TSH in the fetal circulation.

Iodide organification defect in iodine deficiency endemic goiter.

In 17 goitrous persons in an iodine-deficient area, in 23 nongoitrous inhabitants of the same village, in 10 goitrous persons in Athens, and 8 normal controls the perchlorate discharge test was performed, either in the simple standard form or after pretreatment with either 0.5 or 2.0 mg potassium iodide or 2.5 mg carbimazole. With the simple test or with 0.5 mg potassium iodide, there was no significant discharge in any group studied. With 2.5 mg carbimazole, there was a profound discharge of the trapped iodide in both groups in the iodine-deficient area. With 2.0 mg potassium iodide, however, there was a clear discharge in the two goitrous groups (i.e. the one in the endemic area and the second in Athens), a less pronounced discharge in the controls studied in Athens, and no discharge at all in the nongoitrous inhabitants of the iodine-deficient endemic area. These findings provide evidence for an abnormality present in the patients with endemic goiter, most probably faulty iodine utilization due to impaired organic binding. The nongoitrous persons in the endemic areas, on the other hand, seem to be even more efficient in handling the trapped iodide than the controls studied in Athens. These findings may provide an explanation for previous observations that in endemic areas only part of the population develop a goiter, whereas the others adapt successfully to iodine deficiency without significantly enlarging their glands.

Serum thyroid hormone and thyrotropin levels in subjects from endemic goiter regions of New Guinea.

We studied serum thyroid hormone and thyrotropin (TSH) levels in subjects from two regions (Nomane and KarKar) of New Guinea where endemic goiter and/or iodine deficiency are prevalent. The results of the studies in 285 patients from Nomane indicated subnormal serum T4 (mean plus or minus SD, 6.5 plus or minus 2.8 vs 8.4 plus or minus 2.0 mug/1ll ml, for normal Americans, P less than 0.001), supranormal serum T3 (161 plus or minus 51 vs 126 plus or minus 33, ng/100 ml, p less than 0.001), supranormal serum T3/T4 ratio (T3/T4 x 100, 3.1 plus or minus 2.4 vs 1.5 plus or minus 0.4, P less than 0.001) and supranormal serum TSH (16 plus or minus 40 vs 2.7 plus or minus 1.2 muU/ml, P less than 0.001). Serum free T4 and free T3 were measured in 42 subjects. Serum free T4 was subnormal (2.0 plus or minus 0.9 vs 2.8 plus or minus 0.5, ng/100 ml P less than 0.001) and free T3 was elevated (677 plus or minus 150 vs 375 plus or minus 105, pg/100 ml, P less than 0.001). Serum T4 in goitrous patients was significantly lower than that in non-goitrous patients (5.9 vs 6.9 mug/100 ml, P less than 0.005). However, serum T3 and TSH were no different in the presence or absence of goiter. The frequencies of elevated serum TSH or serum T3 in presence of goiter were also no different from those in its absence. The mean values of various thyroid function tests in 37 subjects from KarKar Island were similar to the corresponding values in Nomane subjects. Serum T4, T3 and TSH values in 8 of 13 deaf-mute patients were similar to the corresponding mean values of other inhabitants of the region. However, the remaining 5 patients had deaf-mutism with no appreciable abnormality in thyroid function. Serum TSH correlated inversely with serum T4 (r= -0.31, P less than 0.001). There was, however, no significant relationship between serum TSH and T3 levels. The data suggest that: 1) circulating T4 exerts a significant negative feedback effect on serum TSH level and that this effect of T4 may be even more important than that of circulating T3; 2) factors other than hypothyroidism may be important in the genesis of neurological defects in endemic goiter regions.

Hypothyroidism in an area of endemic goiter and cretinism in Central Java, Indonesia.

In an area of severe endemic goiter in Central Java, Indonesia, clinical overt or mild hypothyroidism appeared to be present in 7 out of 20 cretins and also in 12 out of 94 non-cretinous subjects, all 5-20 years of age, living in the village of Sengi. Hypothyroidism was not found in a control group of 70 subjects of the same age living in Londjong just outside the edemia. In hypothyroid subjects the plasma PBI-concentration was 0.98+/-0.32 mug/100 ml (mean+/-SD) vs. 2.72+/-1.24 mug/100 ml in euthyroid subjects from Sengi and 4.86+/-0.80 mug/100 ml in controls from Londjong. Values for T3 were 56.3+/-3.17 ng/100 ml in hypothyroids, 140.5+/-38.5 ng/100 ml in euthyroids from Sengi and 121.6+/-27.4 ng/100 ml in controls. The TSH levels (geometric mean and range) in these 3 groups were, respectively, 210.1 (108.0-342), 15.6 (3.0-372) and 4.1 (0.8-7.0) muU/ml. The differences between the mean concentration of PBI, T3 and TSH in the hypothyroid and euthyroid groups were highly significant (P less than 0.001). These data strengthen the clinical diagnosis of hypothyroidism in cretins as well as in non-cretinous subjects. All hypothyroid subjects had a PBI less than 1.8 mug/100 ml and T3 less than 120 ng/100 ml and TSH greater than 100 muU/ml. In 8 hypothyroid subjects, restudied 18 months after iodized oil injection, hypothyroidism was either corrected or markedly improved. It therefore appears that iodine deficiency per se in postnatal life may lead to (juvenile) hypothyroidism, which can be corrected by iodine therapy. Our findings have implications for the definition and diagnosis of endemic cretinism. Not all hypothyroid subjects in an area of endemic iodine deficiency should be classified as cretins.