Goitrous Subjects Research Articles

BIOCHEMICAL AND CLINICAL CHARACTERIZATION OF IODINE DEFICIENCY DISORDERS IN CENTRAL INDIA

Background: Iodine (I) is a trace element that is required by both humans and animals. It can be found in a variety of chemical forms, including iodine, iodide (I), and iodate (IO3). It is widely distributed across the earth's ecology, with a concentration in the oceans. Iodine entered the natural cycle from the ocean, the atmosphere, and rainfall, as well as from rainfall into streams and rivers. Iodine is absorbed as iodide in human nutrition. Iodine is a necessary micronutrient and a component of thyroid hormones. Fish and seafood have a high iodine level. The amount of iodine in soil and drinking water varies depending on where it comes from. Iodine shortage produces a variety of negative health consequences, which are referred to as iodine deficiency illnesses (IDD). These conditions are caused by a lack of iodine, which causes insufficient thyroid hormone production.
 Aim: The aim of this study is to characterize the iodine deficiency disorder by biochemical and clinical assessment and to correlate the iodine status with thyroid disorder(s) in adults.
 Material and Method: The samples for this investigation were taken from patients at the Department of Endocrine Surgery. This study comprised a total of 100 hundred goiter patients, who had their urinary iodine excretion and thyroid hormone levels examined. For all goiter patients, the grading of goitre was established using the WHO/UNICEF/ICCIDD approved criteria. TSH, Free T4, Free T3 by using ELISA Method using commercial kits. Anti-microsomal antibody (AMA) or Thyroperoxidase antibody (TPO-Ab) by using ELISA Method using commercial kits. Anti-thyroglobulin antibody (ATG) estimated by using ELISA Method using commercial kits.
 Results: The data for each group were presented as Median and inter quarter range (IQR) The median and IQR of Urinary iodine excretion of the hypothyroid, hyperthyroid and Euthyroid goiter subjects were respectively and there was significant difference in the median urinary iodine excretion. The median and IQR of Urinary iodine excretion of the thyroiditis, thyrotoxicosis, cancer of thyroid and benign goiter respectively and there was significant difference in the median urinary iodine excretion.
 Conclusion: For ages, endemic goitre and cretinism have been recognised as public health issues, and iodine deficiency is thought to be the leading cause of preventable mental retardation. Most countries now include iodine deficiency control as part of their national nutrition policies. To eliminate iodine deficiency, several therapies with high efficacy have been employed, including iodized oil capsules (IOC) and universal salt iodisation (USI). Although some progress has been made, efforts to eliminate this devastating health problem must be hastened. Not only should iodine deficiency be monitored, but so should excessive iodine intake, as this is a problem in various areas, including the camps.
 Keywords: IDD, Goitre, TSH, IOC, USI, ATG, AMA, T4, T3.

Echocardiographic Evaluation of Patients with Goiter in a Nigerian Tertiary Hospital

Background: Goiter is endemic in iodine deficient areas of the world including Nigeria. Cardiovascular disorder is a cause of morbidity in patients with thyroid diseases. These cardiovascular disorders are more likely to be found in patients with hypothyroid or hyperthyroid goiter. Large euthyroid goiter can potentially compromise respiration with potentials for secondary cardiac changes. Despite these, echocardiography is not a routine assessment of these patients. This study set out to determine the baseline cardiac function in a cohort of patients with endemic goiter using echocardiography.
 Materials and Methods: A comparative study of One hundred goiter patients presenting consecutively at the out-patient clinic of a tertiary hospital and 50 age and gender matched healthy non-goitrous control subjects. They all had thyroid function tests, cardiovascular evaluation and echocardiography done.
 Results: The mean ages of the goiter and the control groups were 46.92 + 13.85 and 46.58 + 11.62 years respectively (P=0.8510). The goiter population comprised 12 males and 88 females while the control group had 6 males and 44 females. 47% of the goiter subjects were hyperthyroid, while 44% and 9% were euthyroid and hypothyroid respectively. All the control subjects were euthyroid.
 Systolic and diastolic dysfunction were seen in 18% and 24% of the goiter group respectively, compared to 2% and 5% of the control group (P<0.0001). Hyperthyroid and hypothyroid subgroups had higher rates of both systolic and diastolic dysfunction. Systolic dysfunction was seen in 6.4%, 4.5% and 100% of the hyperthyroid, euthyroid and hypothyroid subgroups respectively while diastolic dysfunction was seen in 23.4%, 9.2 and 100% of the subgroups. Prevalence of systolic and diastolic dysfunction in the euthyroid and control subjects were 4.5% vs 2% (P=0.1228) and 9.2% vs 5% (P=0.2018).
 Conclusion: This study concluded that cardiac dysfunction is common in both hypothyroid and hyperthyroid goiter population while the prevalence of cardiac dysfunction in the euthyroid population is not influenced by the presence of goiter. This may suggest that routine echocardiography is unnecessary in patient with euthyroid goiter.

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

PurposeSalt 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. MethodsGoiter 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. ResultsStudy 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. ConclusionsGrade-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.

Turmeric use is associated with reduced goitrogenesis: Thyroid disorder prevalence in Pakistan (THYPAK) study.

Introduction:South Asian population has a particularly high prevalence of thyroid disorders mainly due to iodine deficiency and goitrogen use. There is no data available for prevalence of thyroid disorders in the general population living in nonmountainous regions of Pakistan.Materials and Methods:A total of 2335 residents of Pak Pattan, Punjab, Pakistan were interviewed about demographic, dietary, medical and environmental history as well as screened for goiter. Individuals of all ages and either gender were included.Results:Median age was 34 (10–88) years and 1164 (49.9%) were males. Median monthly income was 49 (3.9–137) USD. Six hundred and sixty-nine (28.7%) subjects had palpable goiter. 77.5% (n = 462) and 22.5% (n = 133) had World Health Organization Grade I and Grade II goiters respectively, further screened by measuring thyroid-stimulating hormone (TSH). In subjects with TSH <0.4 mg/dL, free T3 and free T4 levels were measured. In 185 goiter subjects when TSH was measured, 50% (n = 93) were euthyroid, 48% (n = 89) were hyperthyroid, and one subject each was hypothyroid and subclinically hyperthyroid. 29/89 hyperthyroid subjects underwent radionuclide scanning. Twelve subjects had heterogeneous uptake consistent with multinodular goiter, 12 subjects had diffuse uptake, two had cold nodules and two had hyperfunctioning single nodules. Goiter was significantly more common among females, unmarried individuals and individuals drinking tube well (subterranean) water. Goiter was less common among those who consumed daily milk, daily ghee (hydrogenated oil), spices, chilies, and turmeric.Discussion:In our study population, goiter was endemic with very high prevalence of hyperthyroidism. Turmeric use was association with reduced goitrogenesis. Further studies to assess iodine sufficiency, thiocyanate exposure and autoimmunity need to be conducted. Masses consuming high goitrogen diets should be educated to incorporate turmeric, spices and green chilies in their cooking recipes, to reduce the risk of goiter development. In addition, use of iodized salt in their daily diet cannot be overemphasized.

The Association between Cobalt Deficiency and Endemic Goiter in School-Aged Children.

BackgroundIn Iran, an iodine deficiency control program was initiated in 1989 by iodizing salt. Despite this program, goiters have remained an endemic condition in most parts of Iran. Thus, it is possible that other factors aside from iodine deficiency may contribute to endemic goiter. The aim of this study was to investigate the association between cobalt deficiency and endemic goiter in a region of Iran with a high prevalence of goiter.MethodsA cross-sectional study was conducted among school children aged 9 to 11 years in the city of Kerman, Iran. In the first phase of the study, a multistage, proportional-to-size, cluster sampling method was used to screen 5,380 out of 29,787 students. After the screening phase, 170 students (130 goitrous and 40 nongoitrous) were randomly selected, and serum and urine specimens were obtained. We measured thyroid function, serum cobalt level, and urinary iodine excretion. Univariate and multiple logistic regression analyses were performed.ResultsThe prevalence of grade 2 goiters was 34.8% (95% confidence interval [CI], 31.5 to 42.5), with both sexes being equally affected. The weight and body mass index of goitrous subjects was significantly lower (P<0.001) than those of nongoitrous subjects. The serum cobalt levels were lower in goitrous subjects than in nongoitrous subjects (4.4±2.9 µg/L vs. 6.4±2.7 µg/L). The urinary iodine levels were also lower in goitrous subjects than in nongoitrous subjects (198.3±108.3 µg/L vs. 270.2±91.1 µg/L). Multiple regression analysis showed that only cobalt deficiency, not iodine deficiency, significantly contributed to the presence of goiter (odds ratio, 0.78; 95% CI, 0.61 to 0.99; P=0.042).ConclusionCobalt deficiency may be an important independent predicator for goiter in endemic regions, especially areas in which goiters persist despite salt iodization programs.

Thiocyanate status does not play a role in the etiology of residual goiter in school children of Isfahan, Iran

Despite long standing iodine supplementation in Iran the prevalence of goiter remains high in some areas. In the present study we investigated the possible role of thiocyanate as a goitrogen in the etiology of goiter in Isfahan, Iran. A total of 2331 (6-13 year old) school children were selected by multistage random sampling. Thyroid size was estimated in each child by inspection and palpation. Urinary iodine concentration (UIC) and urinary thiocyanate (USCN) were measured. Overall, 32.9% of the 2331 students had goiter. The median UIC was 195.5 μg/L. The mean ± SD of USCN in goitrous and nongoitrous subjects was 0.42 ± 0.28 mg/dL and 0.41 ± 0.32 mg/dL, respectively (P=0.86). USCN level in goitrous and nongoitrous boys was 0.41 ± 0.32 mg/dL and 0.43 ± 0.37 mg/dL, respectively (P=0.67). USCN level in goitrous and nongoitrous girls was 0.43 ± 0.26 mg/dL and 0.40 ± 0.28 mg/dL, respectively (P=0.43). Thiocyanate overload does not play a role in high prevalence of goiter in the studied population. We suggest the role of other goitrogenic factors should be investigated in this region.

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.

Thyroid nodules in acromegaly: The role of elastography

Introduction Ultrasound elastography (US-E) is a helpful tool for the diagnosis of thyroid cancer. In acromegaly, multinodular goiter is a common occurrence while the prevalence of thyroid cancer is still matter of debate. Our aims were to evaluate thyroid nodules in acromegaly and to assess the accuracy of US-E in providing information on their nature (benign vs. malignant) using cytological analysis as a reference. Materials and methods US-E was performed in 25 patients with acromegaly (active in 10 cases, medically controlled in 8, and cured by pituitary surgery in 7), each of whom had at least one solid thyroid nodule. A total of 90 nodules were classified according to the elastography scores (ES): ES1 and ES2 for soft nodules, ES3 and ES4 for an elastic lesions. FNAC was performed in 78.6% of the ES 4 lesions and 54.1% of the ES 3 nodules. Results Fourteen of the 90 nodules (15.5%) displayed an ES of 1, 25 (27.7%) an ES of 2, 37 (41.3%) an ES of 3, and 14 (15.5%) an ES of 4. The prevalence of hard nodules in patients with active acromegaly (68.9%) was greater than that observed in patients with cured (44.4%) or controlled (52.5%) acromegaly. The prevalence of hard nodules in the total series (56.7%) was higher than that reported in nonacromegalic goitrous subjects. All thyroid nodules subjected to FNAC were negative for malignant cells and follicular lesions. Discussion Acromegaly (particularly active forms) is associated with a high prevalence of stiff thyroid nodules that exceeds that observed in nonacromegalic patients with goiters (33.7%). However, these nodules were never malignant at cytology, and their firmness is probably due to fibrosis. US-E therefore appears to be of limited value for the diagnosis of thyroid cancer in patients with acromegaly.

Residual Goiter in Semirom; Iodine Status and Thiocyanate Overload Do Not Play a Role

This study was performed to investigate the role of thiocyanate overload in the etiology of endemic goiter in schoolchildren of Semirom, Iran. A total of 1828 schoolchildren were selected by multi-stage random sampling. Urinary iodine concentration (UIC) and urinary thiocyanate (USCN) were measured in a group of these children. The median UIC was 18.5 microg/dl. The mean +/- SD of USCN in goitrous and nongoitrous subjects did not differ significantly (0.75 +/- 0.78 mg/dl vs. 0.63 +/- 0.40 mg/dl; p = 0.30). Finally, we concluded that neither iodine deficiency nor thiocyanate overload contributed to the high prevalence of goiter in Semirom. The role of other goitrogenic factors should be investigated in this region.

Elastosonographic evaluation of thyroid nodules in acromegaly

Ultrasound-elastography (US-E) appears to be a helpful tool for the diagnosis of thyroid cancer. In acromegaly, the prevalence of thyroid cancer is still debated. The aims of this study were to evaluate thyroid nodules in acromegaly and to establish the accuracy of US-E in providing information on their nature, using cytological analysis as a reference. US-E was applied to 90 nodules detected in 25 acromegalic patients and to 94 nodules found in 31 non-acromegalic goitrous subjects. The lesions were classified according to the elasticity scores (ES) as soft (ES 1-2) or hard (ES 3-4). Fine needle aspiration cytology could be performed in 60.8% of hard nodules in acromegalics and in 86.7% of hard nodules in controls. The prevalence of hard nodules was significantly higher in the whole group of acromegalic patients than in controls (56.8 vs 16.0%, P<0.0001). The prevalence of hard nodules in patients with active acromegaly (68.9%) was greater, though not to a statistically significant extent, than that observed in cured (44.4%) and controlled (52.5%) patients. Cytology revealed malignancy or suspect malignancy in four of the nodules of non-acromegalic subjects and in none of the nodules of acromegalic patients. This study has demonstrated a high prevalence of stiff thyroid nodules in acromegaly, greater than that found in non-acromegalic goitrous subjects. In acromegalics, hard nodules appeared not to be malignant on cytopathological examination and are probably of fibrous nature. Thus, US-E appears to be of limited value for the diagnosis of thyroid cancer in acromegaly.

Daily iodine intake in healthy children and adults and in goitrous patients in nonendemic Yugoslav area.

Daily iodine intake has been investigated in 52 healthy children (5-14 years), 112 healthy adults and in 39 patients with nontoxic goiter from the area of Zagreb/Yugoslavia. Fourteen goitrous patients received 1-thyroxine 150 micrograms daily for at least three months before the examination. Iodine intake has been estimated on the basis of urinary iodine excretion (microgram I-/g creatinine) in the first morning specimen. Iodine excretion in nontreated goitrous patients (92 +/- 30; Mean +/- SD) was significantly lower than in healthy adults (112 +/- 38), while the value in treated goitrous patients (165 +/- 69) was significantly higher than that in nontreated goitrous and healthy adult subjects. The results suggest that Zagreb area, although classified as nonendemic, has borderline iodine intake, and that relative iodine deficiency is of importance in goiter formation. The authors plead for increased daily iodine intake through increased table salt iodisation from actual amount of 10 to 20 to 25 mg KI/kg salt in order to provide an average daily intake of 250 micrograms of iodine.

Short Telomeres, Telomerase Reverse Transcriptase Gene Amplification, and Increased Telomerase Activity in the Blood of Familial Papillary Thyroid Cancer Patients

Differentiated papillary thyroid cancer is mostly sporadic, but the recurrence of the familial form has been reported. Short or dysfunctional telomeres have been associated with familial benign diseases and familial breast cancer. The aim of our work was to study the telomere-telomerase complex in the peripheral blood of patients with familial papillary thyroid cancer (FPTC), including the measurement of relative telomere length (RTL), telomerase reverse transcriptase (hTERT) gene amplification, hTERT mRNA expression, telomerase protein activity, and search of hTERT or telomerase RNA component gene mutations. Cumulating a series of patients seen at the University of Siena and a series at the University of Rome, the experiments were conducted in 47 FPTC patients, 75 sporadic papillary thyroid cancer (PTC) patients, 20 patients with nodular goiter, 19 healthy subjects, and 20 unaffected siblings of FPTC patients. RTL, measured by quantitative PCR, was significantly (P < 0.0001) shorter in the blood of FPTC patients, compared with sporadic PTCs, healthy subjects, nodular goiter subjects, and unaffected siblings. Also by fluorescence in situ hybridization analysis, the results confirmed shorter telomere lengths in FPTC patients (P = 0.01). hTERT gene amplification was significantly (P < 0.0001) higher in FPTC patients, compared with the other groups, and in particular, it was significantly (P = 0.03) greater in offspring with respect to parents. hTERT mRNA expression, as well as telomerase activity, was significantly higher (P = 0.0003 and P < 0.0001, respectively) in FPTC patients, compared with sporadic PTCs. RTL, measured in cancer tissues, was shorter (P < 0.0001) in FPTC patients, compared with sporadic PTCs. No mutations of the telomerase RNA component and hTERT genes were found. Our study demonstrates that patients with FPTC display an imbalance of the telomere-telomerase complex in the peripheral blood, characterized by short telomeres, hTERT gene amplification, and expression. These features may be implicated in the inherited predisposition to develop FPTC.

Distribution Of Serum T3/T4 Quotient In Euthyroid Goitrous Subject In Nigeria- A Probable Biochemical Marker Of Goiter Endemia

Objective. To determine the relationship between the serum levels of (T4) thyroxin, (T3) Tri-iodothyronine, and (TSH) Thyrotropin versus the goiter size in an endemic euthyroid goitrous subject. Materials and Methods. Serum levels of thyroxin (T4), Tri-iodothyronine(T3), and thyrotrophin (TSH) were determined by “ELISA” technique in 58 adult euthyroid goitrous subjects with various grades of endemic giotre, and in 42 adult normal subjects used as control. Findings. The serum thyroxin (T4) levels were depressed to a low normal range in most of the subjects with advanced goitre, while Tri-iodothyronine (T3) levels were in the high normal to supra normal region. Thyroid size was found to bear a negative correlation with serum Thyroxin (T4) levels levels(r = 0.6; p=0.05) and positive correlation with Tri-iodothyronine(T3) levels (r = 0.8; p=0.001), as well as with serum thyrotropin (TSH) concentration (r = 0.9; p-0.001). The serum T3/T4 ratio showed a strong positive correlation with the size of the enlarged thyroids in this group of patient, (r = 0.8; p=0.001). Conclusion. The findings suggest that the serum T3/T4 ratio in the euthyroid goitrous subjects may probably be used as a valuable biochemical indicator in the epidemiological assessment of endemic goiytre in a population Highland Medical Research Journal Vol.2(1) 2004: 17-21

Residual goitre in the postiodization phase: iodine status, thiocyanate exposure and autoimmunity.

This study was done to assess goitre prevalence, thyroid functional status and cause of residual goitre among school children in the postsalt iodization phase in India. A cross-sectional study in which, 14762 school children in the age group of 6-18 years, from different States and Union territories of India, were evaluated for goitre prevalence, urinary iodine and thiocyanate excretion, functional status of the thyroid as well as serological and cytopathological markers for thyroid autoimmunity. Urinary iodine (wet ashing method), urinary thiocyanate (colourimetric method), serum thyroxine [in-house radioimmunoassay (RIA)], serum TSH (IRMA), antithyroid microsomal and antithyroglobulin antibodies (haemagglutination method) were estimated. Fine-needle aspiration cytology was performed in all goitrous subjects giving consent. The overall goitre prevalence was 23% (27.1% girls; 17.8% boys, P < 0.001). Subjects belonging to poor socio-economic strata had significantly higher goitre prevalence. Median urinary iodine excretion (UIE) in goitrous subjects (2-53 micromol/l) was significantly higher than in controls (2-24 micromol/l; P < 0.001). Levels of UIE observed among goitrous subjects showed no relationship with the presence or absence of thyroid dysfunction or with thyroid antibody status. High titres (> or = 1:1600) of TMA were present more often in goitrous subjects (6.08%) than nongoitrous controls (0.34%; P < 0.001) and in girls (7.3%) than boys (2.35%; P < 0.001). TMA positivity were significantly more among goitrous subjects with thyroid dysfunction than in euthyroid subjects. Significantly higher median urinary thiocyanate (USCN) excretion was observed in goitrous subjects (0.75 mg/dl) compared to controls (0.64 mg/dl; P < 0.001) and goitrous girls compared to goitrous boys. USCN excretion of goitrous subjects and controls showed no relationship with functional or thyroid antibody status in various groups. Persistent, albeit reduced prevalence of goitre, despite adequate iodine prophylaxis, suggests existence of additional factors in goitrogenesis in India. Thyroid autoimmunity can explain only a part of the goitre prevalence. The role of goitrogens in residual goitre prevalence is brought forth.

Familial aggregation of autoimmune thyroiditis in first-degree relatives of patients with juvenile autoimmune thyroid disease.

Several studies have shown aggregation of autoimmune thyroiditis in families by estimation of thyroid antibodies. However, the prevalence by concurrent estimation with fine-needle aspiration cytology (FNAC) and thyroid antibodies has not been previously reported. We therefore studied 222 first-degree relatives (group 1) of 71 index cases diagnosed as lymphocytic thyroiditis on FNAC and 81 family members (group 2) of 23 goitrous children diagnosed as colloid goiter on FNAC for comparison. Successful FNAC conducted in 122 group 1 subjects revealed lymphocytic thyroiditis in 51 (42%), whereas lymphocytic thyroiditis was diagnosed in only 5 goitrous subjects (13%) in group 2. Among group 1 subjects with FNAC-proven lymphocytic thyroiditis, antithyroid peroxidase (TPO) antibodies were found in 35 (67%), while in anti-TPO antibody positive goitrous relatives of group 1, lymphocytic thyroiditis was found in 36 (78%). Eight new cases of overt hypothyroidism and 45 new cases of subclinical hypothyroidism were diagnosed among group 1 subjects. Our study suggests: (1). familial clustering of autoimmune thyroiditis; (2). if only FNAC or thyroid antibodies is used for diagnosis of autoimmune thyroiditis in children, 22%-33% of cases are likely to be missed; and (3). serum thyrotropin (TSH) should be offered to all first-degree relatives of patients with juvenile autoimmune thyroiditis.

Childhood goitre and urinary iodine excretion in Hong Kong.

Goitre is common among growing children and adolescents. To define the aetiology of goitre in adolescents of Hong Kong and to examine their current level of iodine intake, this cross-sectional survey of goitre in high school students was performed and urine samples were collected for the analysis of iodine excretion. Screening examinations were carried out in 2439 secondary school students aged 12-18 years from ten randomly selected high schools in Hong Kong. Blood samples were obtained from all goitrous subjects for the determination of serum TSH, free T4 and thyroid antibodies. We obtained 476 random urine samples and 80 24-h urinary collections for the analysis of iodine excretion. Of these, 85 subjects (3.5%) had goitre, 70 had simple goitre. Chronic lymphocytic thyroiditis was found in ten subjects. Two had Graves' disease and three had nodular goitre. The median urinary iodine concentration for the random urine samples was 190 microg/l (1.50 micromol/l) or 158 microg/g creatinine. The median 24-h urinary excretion of iodine was 189 microg (1.49 micromol) per day. This cross-sectional study demonstrates the spectrum of thyroid disease in Chinese adolescents in Hong Kong. Their urinary iodine excretion was adequate and much higher than those of children from many European countries and coastal cities of China.

The effects of different doses of oral iodized oil on goiter size, urinary iodine, and thyroid-related hormones.

The prevention of iodine deficiency is still a worldwide concern. This study, conducted in Soja in western Sudan, was carried out to evaluate the effects of a dose of iodized oil sufficient enough to give maximum protection against goiter and provide an acceptable iodine supply without side-effects over a sufficiently long period of time. Adult goitrous subjects (n = 117) were randomly assigned to three groups, A, B, and C, and received a single oral dose of 200, 400, or 800 mg iodine, respectively. Urine and blood samples were collected at the start of the study and monitored for 1 yr. In the 3 groups, mean serum T4 and median urinary iodine and serum TSH values were restored to reference limits, and these were maintained for about 1 yr. In each treatment group, about two thirds of the subjects displayed a reduction in goiter size, and the 400- and 800-mg doses were not more efficient than the 200-mg dose to accomplish normalization of thyroid hormone values. A temporary rise in TSH was noted 1 week after iodine administration in 1, 3, and 10 subjects, respectively, and 1, 0, and 3 subjects showed biochemical signs of thyrotoxicosis during the year after treatment with the 3 different doses. The data indicate that oral administration of 200 mg iodine is effective and acceptable for treating iodine deficiency in adults for 1 yr. Because of the risks of side-effects and the shortage of medical resources, higher doses are not recommended.

Endemic goiter in Morocco (Skoura-Toundoute areas in the high atlas).

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

Genetic linkage studies of thyroid peroxidase (TPO) gene in families with TPO deficiency.

We have conducted biochemical and genetic studies in five unrelated families (denoted A, C, R, P, and G), which included nine goitrous subjects (five borderline euthyroid and four hypothyroid) with complete (n = 6) or partial (n = 3) thyroid peroxidase (TPO) deficiency. Thyroid tissue was obtained from four subjects, respectively, in families A, C, and R. No iodide organification or iodide incorporation into protein was present in families A and C. The two affected siblings in family R had a low normal tissue thyroperoxidase activity. Using a 0.8-kilobase (kb) cDNA clone (pM5) encoding 30% of the cDNA of human TPO gene down-stream from basepair 730 and four restriction enzymes (TaqI, PstI, BglI, and BglII), we were unable to find any polymorphisms in family A. In another family (C) blood samples were obtained from only two family members, and consequently, it was not possible to determine linkage. DNA from families G, P, and C showed biallelic polymorphisms when digested with BglII, at 8.7 and 8.5 kb. In family R we detected two biallelic polymorphisms at 9.0 and 8.5 kb, and the 9.0-kb bands were clearly larger than 8.7-kb bands found in the other subjects. Also, there was an absence of a 4.0- to 3.9-kb band that may represent a partial gene deletion. With PstI-restricted DNA a possible deletion of 5.5-kb band was also present in affected siblings of family R. The logarithm of odds (Lod) score analyzed from the family with inbreeding (R) was compatible with linkage of disease and the TPO gene (Lod = 2.08). When this method was used with families G and P, the Lod score was inconsistent with linkage between disease and the TPO gene. These data suggest that the cause of TPO deficiency in these families is heterogeneous. However, the restriction fragment length polymorphism pattern of BglII-restricted DNA in the R family strongly suggests that a partial TPO gene deletion has occurred in this family.

Natural course of iodine-induced thyrotoxicosis (Jodbasedow) in endemic goiter area: a 5 year follow-up.

In the Balsas region of North Brazil (85% prevalence of goiter), 1876 goitrous subjects (1663 with goiter grade I and II and 103 with grade III multinodular goiter) were treated with 1 ml of iodized oil im (l-oil). From the population with grade III goiter we were able to follow-up for 5 yr 13 euthyroid goitrous patients (group 1) and 8 goitrous individuals (group 2) who developed iodine-induced thyrotoxicosis (IIT, 0.42% of the total population or 7.76% of the multinodular goiter subjects). The two groups were matched for age and goiter size, and had no significant differences in the baseline levels of thyroid hormone concentration, T3/T4 ratio or mean serum TSH. However, group 2 had a higher concentration of serum Tg, and 48 h after challenge with 10 U of bovine TSH (bTSH) had a significantly higher absolute release of T3 and Tg than group 1. In 4 patients IIT was transitory and resolved by 12 months. Four other subjects, however, maintained a mild clinical form of IIT that only normalized at 50 months. Only one patient needed treatment with methylmercaptoimidazol. There was no evidence of autoantibodies (TSH-receptor inhibiting antibody, anti-Tg or anti-microsomal antibodies) against thyroid antigens in group 2 patients. All subjects, including those with thyrotoxicosis, showed a remarkable shrinkage of the goiter by 60 months which was reflected by a significantly lower absolute response of T3 and Tg after bTSH.(ABSTRACT TRUNCATED AT 250 WORDS)