Related Articles

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 μg/dL (range 1-80 μg/dL). It was 17.9 μg/dL and 19 μg/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.

BACKGROUND:

Iodine deficiency produces the spectrum of iodine deficiency disorders (IDDs) including endemic goiter, hypothyroidism, cretinism and congenital anomalies. Other factors, including goitrogens and micronutrient deficiencies may influence the prevalence and severity of IDDs and response to iodine supplementation. An association between zinc and goiter has previously been reported.

METHODS:

A cross sectional study investigating an association between goiter and serum zinc status was performed in 2003 in a mountainous region of Iran. One thousand eight hundred twenty-eight children were selected by multistage cluster sampling. Goiter staging was performed by inspection and palpation. Serum zinc, total thyroxine, thyroid stimulating hormone and urinary iodine concentration were measured in a group of these children.

RESULTS:

Thirty six and seven tenth percent of subjects were classified as goitrous. Serum zinc level in goitrous and nongoitrous children was 82.80 ± 17.85 and 83.38 ± 16.25 μg/dl, respectively (p = 0.81). The prevalence of zinc deficiency (serum zinc ≤65 μg/dl) in goitrous and nongoitrous children did not differ significantly (9.3 % vs. 10.8%, p = 0.70).

CONCLUSIONS:

Goiter is still a public health problem in Semirom. According to the present study zinc status may not play a role in the etiology of goiter in Semirom school children. However, the role of other goitrogens or micronutrient deficiencies should be investigated in this region.

Background & objectives:

Despite years of salt iodization, goitre continues to be a major public health problem worldwide. We examined the prevalence of goitre in the post-iodization phase and the relationship of goitre with micronutrient status and thyroid autoimmunity in school children of Chandigarh, north India.

Methods:

Two phase study; in the first phase, 2148 children of 6 to 16 yr were screened for goitre by two independent observers as per the WHO grading system. In the second phase, a case-control study, 191 children with goitre and 165 children without goitre were compared with respect to urinary iodine, iodine content of salt, serum levels of T3, T4, TSH, anti-TPO (thyroid peroxidase) antibody, haemoglobin, ferritin and selenium.

Results:

Prevalence of goitre in the studied subjects was 15.1 per cent (13.9% in 6 to 12 yr and 17.7% in 13 to 16 yr age group, P= 0.03). Median urinary iodine excretion in both the groups was sufficient and comparable (137 and 130 µg/l). 3.2 per cent children with goitre and 2.4 per cent without goitre had hypothyroidism (subclinical and clinical) and only one child with goitre had subclinical hyperthyroidism. Nine (4.9%) children in the goitre group and 3 (1.9%) in control group had anti-TPO antibody positivity. The median serum selenium levels were not different in both the groups (181.9 and 193.5 µg/l). Seventy one (37.4%) of the goitrous children had anaemia (haemoglobin <12 g/dl) as compared to 41 (24.8%) of the control group (P <0.01). More number of goitrous children (39, 20.6%) were depleted of tissue iron stores (serum ferritin <12 µg/l) as compared to controls (11, 6.4%; P<0.001). Serum ferritin level negatively correlated with the presence of goitre (r = - 0.22, P =0.008) and had an OR of 2.8 (CI 1.20 - 6.37, P =0.017).

Interpretation & conclusions:

There was a high prevalence of goitre in young children despite iodine repletion and low thyroid autoimmunity. The concurrent iron deficiency correlated with the presence of goiter. However, the cause and effect relationship between iron deficiency state and goitre requires further elucidation.

Simple goitre is highly prevalent in New Zealand, and there is considerable incidence of toxic goitre. The ætiology of simple goitre seems fairly well established, and an attempt is being made to apply the data from simple goitre to the problems of toxic goitre.

Endemic goitre is of great antiquity among the Maoris, and has been described among Europeans for about fifty years. It occurs in both men and animals. At five years its incidence is similar in boys and girls, later it decreases in boys but increases greatly in girls. It is often hereditary, and many children are born goitrous. In children it is generally small, but may enlarge and cause pressure, myxœdema and toxicity. Its incidence varies greatly in different districts.

The only cause found consistent with this variation in distribution is lack of iodine in the soil. An inverse ratio has been demonstrated between the iodine content of the soil and the incidence of goitre in school children in thirty-three districts. The iodine content of the soil is reflected in the food raised upon it.

The daily iodine intake was estimated at 35 microgrammes in a non-goitrous, and at 20 microgrammes in a goitrous district.

The amount of iodine involved is infinitesimal, and its intake can be ensured by the use of salt for ordinary consumption, which contains four parts per million of potassium iodide.

Toxic goitre is also frequent: in this connexion, the influence of iodine on the thyroid has been investigated. If starved of iodine the thyroid adapts itself either by increasing its colloid or by a diffuse hyperplasia, both may occur in different parts of the same gland. Simple goitre is the response of the healthy thyroid to iodine deficiency, the responding areas may be diffuse or adenomatous, and degenerations may occur. Such goitres may be treated with iodine, in children re-adjustment to the increased intake is readily made, but in adults long accustomed to a low intake, excess often causes too great hormone production, with toxic symptoms, hence the minimal dose alone is permissible in iodized salt.

Goitre stored with iodine at low pressures may become toxic under stress, and this may be precipitated by iodine. The prevalence of toxic goitre may be partly due to the prescription of iodides in therapeutic doses for common ailments.

Diffuse colloid goitre may subside under physiological iodine, the adenomatous is more prone to toxic symptoms and may go on to secondary Graves' disease or to myxœdema. Diffuse hyperplasia is a possible manifestation of iodine deficiency as primary Graves' disease. Lugol's solution probably allows of a temporary storage in this condition. Iodine has certainly some bearing on the problems of toxic goitre.

The Ukinga and Uwanji regions, located in the southern highlands of Tanzania, were studied for the degree of iodine deficiency and the incidence of goitre and hypothyroidism, respectively. A urinary iodine excretion as low as 17.6 +/- 9.3 micrograms/g creatinine was observed in Wangama village. The mean goitre prevalence in 27 villages in Uwanji ranged between 65 and 96% (n = 3031 schoolchildren). Of 681 pregnant women from Ukinga 79.6% had goitre. The prevalence of cretinism as estimated on clinical criteria was 3% in Magoye (Uwanji). A normal serum TSH (below 2.1 mU/l) was observed in only 12 out of 66 school children before iodine prophylaxis, whereas the T4/TBG ratio was decreased in 36 of 63 cases. Blood spot TSH levels in newborn infants (n = 219) from mothers without iodine supplementation were above 12 mU/l in 45%. In contrast, only 20.3% of the newborn (n = 118) had elevated blood spot TSH (p less than 0.002) when the mothers had received an iodised oil injection during pregnancy. Most of the newborn (n = 18; 75%) of the latter group with elevated TSH (n = 24) came from mothers who had received the iodine injection only 1-25 days before delivery. Maternal iodine prophylaxis in late pregnancy does not increase the rate of neonatal hypothyroidism. Conclusions: It has been confirmed that severe iodine deficiency resulting in endemic goitre, cretinism, and hypothyroidism is prevalent in the regions studied. Dried blood spot TSH determinations may serve as an index for the efficiency of iodine prophylaxis programmes. Such a programme was carried out with relatively little expenditure and effort on a large scale basis.

In the Southern Highlands of Tanzania the prevalence of endemic goitre due to iodine deficiency is in the range of 90% and hypothyroidism in the range of 50% of schoolchildren. The present study confirms these data and documents the beneficial effect of Lipiodol injections on thyroid function in children around the age of puberty compared with untreated children from the same villages. On the other hand, a decrease in the prevalence of goitre could not be shown. A beneficial effect is shown for infants of mothers who received iodine during pregnancy. It seems that this form of supplementation is sufficient for breast fed children for more than three years, even when a second child has been delivered in the meantime. In contrast, older siblings of these babies may become hypothyroid when breast feeding is stopped. The determination of thyroid autoantibodies in iodine treated and untreated children and in young adults showed no increasing prevalence of positive findings thus excluding iodine induced chronic thyroiditis at least in the young target population.

We studied two sisters who developed large non-toxic goitres in adolescence. Deiodinase deficiency was diagnosed by a rapid thyroid uptake of radioactive iodine (RAI) at 2 hours associated with a marked fall in thyroidal 131I by 24 hours. Serial RAI scans in the second patient documented evolution of the iodine-deficient state. Conservation of intra-thyroidal iodine stores was maintained by avid iodine uptake and failure to release organified 131I. With progressive loss of inorganic iodine, hypothyroidism developed, associated with a rise in serum TSH which further exacerbated the loss of iodine. Treatment with L-thyroxine resulted in an improvement of thyroid function, but normalization was achieved only after small doses of Lugol's iodine were administered. These studies illustrate the variable nature and late onset of an inborn error of thyroid metabolism. This family supports an autosomal recessive mode of inheritance for deiodinase deficiency. We have documented progression from a euthyroid to hypothyroid state resulting from decompensation of iodine conservation mechanisms.

Background

The ultrasonographic estimation of thyroid size has been advocated as being more precise than palpation to diagnose goitre. However, ultrasound also requires technical proficiency. This study was conducted among Saharawi refugees, where goitre is highly prevalent. The objectives were to assess the overall data quality of ultrasound measurements of thyroid volume (Tvol), including the intra- and inter-observer agreement, under field conditions, and to describe some of the practical challenges encountered.

Methods

In 2007 a cross-sectional study of 419 children (6-14 years old) and 405 women (15-45 years old) was performed on a population of Saharawi refugees with prevalent goitre, who reside in the Algerian desert. Tvol was measured by two trained fieldworkers using portable ultrasound equipment (examiner 1 measured 406 individuals, and examiner 2, 418 individuals). Intra- and inter-observer agreement was estimated in 12 children selected from the study population but not part of the main study. In the main study, an observer error was found in one examiner whose ultrasound images were corrected by linear regression after printing and remeasuring a sample of 272 images.

Results

The intra-observer agreement in Tvol was higher in examiner 1, with an intraclass correlation coefficient (ICC) of 0.97 (95% CI: 0.91, 0.99) compared to 0.86 (95% CI: 0.60, 0.96) in examiner 2. The ICC for inter-observer agreement in Tvol was 0.38 (95% CI: -0.20, 0.77). Linear regression coefficients indicated a significant scaling bias in the original measurements of the AP and ML diameter and a systematic underestimation of Tvol (a product of AP, ML, CC and a constant). The agreement between re-measured and original Tvol measured by ICC (95% CI) was 0.76 (0.71, 0.81). The agreement between re-measured and corrected Tvol measured by ICC (95% CI) was 0.97 (0.96, 0.97).

Conclusions

An important challenge when using ultrasound to assess thyroid volume under field conditions is to recruit and train qualified personnel to perform the measurements. Methodological studies are important to assess data quality and can facilitate statistical corrections and improved estimates.

Background

The so called “big-big” prolactin (Prl), also known as macroprolactin is formed by Prl-immunoglobulin (Prl-IgG) complexes and may cause elevation of serum Prl concentrations measured by standard assays, potentially leading to unnecessary investigations and/or treatment. In our study, we have endeavoured to assess the prevalence of macroprolactinaemia in euthyroid, regularly menstruating women with thyroid disease, as well as to assess whether autoimmune thyroid disease may result in an increased prevalence of macroprolactinaemia.

Material and methods

We measured serum Prl in 182 regularly menstruating women aged 32.7 ± 7.5 years (mean ± SD, range 17–46 years) who attended endocrine clinic either for investigation of non-toxic goitre (n = 86, age 33.2 ± 7.8 years) or with autoimmune thyroid disease (n = 96, age 32.3 ± 7.2 years). Autoimmune thyroid disease was defined as raised titre of at least one anti-thyroid antibody [anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-Tg) and/or anti-TSH-receptor (anti-TSH-R) antibodies]. All women were clinically and biochemically euthyroid, either without or on treatment with L-thyroxine. In those with raised Prl (i.e., above 530 mIU/l) we ruled out the presence of macroprolactinaemia by polyethylene glycol (PEG) precipitation method.

Results

There was no significant age difference between women with and without autoimmune thyroid disease (p = 0.84). Raised Prl concentrations were found in 10 women with thyroid disease (5.5%), and of those a significant macroprolactinaemia (i.e., reduction of Prl concentrations of more than 60% after PEG precipitation) was found in 9 subjects (4.94%). There were no differences in the prevalence of macroprolactinaemia between women with autoimmune thyroid disease (4 out of 96), and without autoimmune thyroid disease (5 out of 86, p = 0.75).

Conclusions

Approximately one out of twenty women with regular menses is likely to have raised serum Prl that is usually caused by the presence of macroprolactinaemia. Though structure of macroprolactin involves Prl-IgG complexes, there is no evidence that autoimmune thyroid disease is associated with raised prevalence of macroprolactinaemia.

Although Baltistan, north east Pakistan, is in a region of iodine deficiency disorders, the distribution of goitre within the district, according to age and sex, has not been clearly defined. To establish the prevalence of the condition and to measure the reported difference in prevalence in the north and south of the district thyroid size was assessed in new patients attending the Aman clinic, Khapalu, and outlying areas between April and September from 1981 to 1986. Samples of potable water collected from villages were analysed for iodine (as iodide) concentrations in Britain. Population weighted prevalences were: in the north in males 20.4%, in females 28.1% and in the south in males 13.9%, in females 21.2%. There was an overall deficiency of iodine in the water (mean iodine (as iodide) concentrations (north) 11.0 nmol/l (1.4 micrograms/l), (south) 11.8 nmol/l (1.5 micrograms/l) (95% confidence interval -0.7 to 0.9). The differences followed the Main Karakoram Thrust, suggesting a geological goitrogen in the north, which might be minerals containing ions such as BF4- and SO3F-, and molybdenite and calcium, which are present in rocks in Baltistan. A new hypothesis for the genesis of endemic goitre is proposed--that is, that continents on crustal plates drift across the earth and collide, one plate sliding under the other and melting, giving rise to characteristic mineral assemblages in the overlying rocks. As the minerals weather out they enter the diet of the local population, where in the presence of iodine deficiency they produce or enhance iodine deficiency disorders. Despite the current iodised oil campaign by the Pakistani government with Unicef a long term working iodisation programme is still urgently needed.

Background

Iodine deficiency is severe public health problem in Ethiopia. Although urinary iodine excretion level (UIE) is a better indicator for IDD the goitre rate is commonly used to mark the public health significance. The range of ill effect of IDD is however beyond goitre in Ethiopia. In this study the prevalence of goitre and its association with reproductive failure, and the knowledge of women on Iodine Deficiency were investigated.

Methods

A cross-section community based study was conducted during February to May 2005 in 10998 women in child bearing age of 15 to 49 years. To assess the state of iodine deficiency in Ethiopia, a multistage "Proportional to Population Size" (PPS) sampling methods was used, and WHO/UNICEF/ICCIDD recommended method for goitre classification.

Results

Total goitre prevalence (weighted) was 35.8% (95% CI 34.5–37.1), 24.3% palpable and 11.5% visible goitre. This demonstrates that more than 6 million women were affected by goitre.

Goitre prevalence in four regional states namely Southern Nation Nationalities and People (SNNP), Oromia, Bebshandul-Gumuz and Tigray was greater than 30%, an indication of severe iodine deficiency. In the rest of the regions except Gambella, the IDD situation was mild to moderate. According to WHO/UNICEF/ICCIDD this is a lucid indication that IDD is a major public health problem in Ethiopia. Women with goitre experience more pregnancy failure (X2 = 16.5, p < 0.001; OR = 1.26, 1.12 < OR < 1.41) than non goitrous women. Similarly reproductive failure in high goitre endemic areas was significantly higher (X2 = 67.52; p < 0.001) than in low. More than 90% of child bearing age women didn't know the cause of iodine deficiency and the importance of iodated salt.

Conclusion

Ethiopia is at risk of iodine deficiency disorders. The findings presented in this report emphasis on a sustainable iodine intervention program targeted at population particularly reproductive age women. Nutrition education along with Universal Salt Iodization program and iodized oil capsule distribution in some peripheries where iodine deficiency is severe is urgently required.

OBJECTIVE--To investigate the long term effect of radioactive iodine on thyroid function and size in patients with non-toxic multinodular goitre. DESIGN--Consecutive patients with multinodular non-toxic goitre selected for radioactive iodine treatment and followed for a minimum of 12 months (median 48 months) after an intended dose of 3.7 MBq/g thyroid tissue corrected to a 100% uptake of iodine-131 in 24 hours. PATIENTS--69 patients with a growing multinodular non-toxic goitre causing local compression symptoms or cosmetic inconveniences. The treatment was chosen because of a high operative risk, previous thyroidectomy, or refusal to be operated on. MAIN OUTCOME MEASUREMENTS--Standard thyroid function variables and ultrasonically determined thyroid volume before treatment as well as 1, 2, 3, 6, and 12 months after treatment and then once a year. RESULTS--56 patients were treated with a single dose of 131I, 12 with two doses, and one with four doses. In 45 patients treated with one dose and remaining euthyroid the median thyroid volume was reduced from 73 (interquartile range 50-106) ml to 29 (23-48) ml at 24 months in the 39 patients in whom this was measured during follow up. The median reduction was 40 (22-48) ml (60% reduction, p < 0.0001), half of which occurred within three months. Patients treated with two doses as well as those developing hypothyroidism and hyperthyroidism had a significant reduction in thyroid volume. Eleven patients developed hypothyroidism (cumulative five year risk 22%, 95% confidence interval 4.8% to 38.4%). Side effects were few: three cases of hyperthyroidism and two cases of radiation thyroiditis. Only one patient was dissatisfied with the result; she was referred for operation six months after treatment. CONCLUSIONS--A substantial reduction in thyroid volume accompanied by a low incidence of hypothyroidism and few side effects makes the use of radioactive iodine an attractive alternative to surgery in selected cases of non-toxic multinodular goitre.

The distribution of mortality from thyrotoxicosis among women in England and Wales during 1968-78 correlates with the previous prevalence of endemic goitre. Mortality from the disease rose to a peak in the decade 1931-40 and then declined. This peak affected all age groups and can be attributed to the high fatality from surgery before the introduction of preoperative iodine to prevent thyroid crisis. An apparent cohort effect, whereby cohorts born from 1871 to 1886 experienced the highest mortality, may be explained by generations with a high prevalence of endemic goitre becoming exposed to increasing dietary iodine intake in later life.

Images

Enlargement of the thyroid is common, especially in areas of endemic iodine deficiency. Substernal enlargement of a goitre can cause compression of several mediastinal structures. As a consequence of tracheal compression and tracheomalacia, syndromes of chronic respiratory distress occur and intercurrent upper respiratory infections may lead to acute respiratory failure. Superior vena cava syndrome secondary to compression by a substernal goitre may be complicated by venous thrombosis. Although dysphagia is the most frequent oesophageal symptom of a substernal goitre, upper gastrointestinal bleeding from 'downhill' oesophageal varices may be an initial presentation. Arterial compression or thyrocervical steal syndrome by large substernal goitres occasionally cause cerebral hypoperfusion and stroke. Recurrent and phrenic nerve palsies, as well as Horner's syndrome, occur secondary to non-malignant mediastinal goitres and may resolve after surgery. Substernal goitres rarely cause therapy-resistant pleural effusions, chylothorax and pericardial effusion. In conclusion, although cervical goitres are easily recognised, the initial presentation of mainly substernal goitres may be unusual.

Images

Thyroid disease is a common paediatric disorder that affects up to 3.7% of school-aged children, and it usually presents with a goitre. By far, the most frequent cause of a goitre is autoimmune thyroid disease, although a benign colloid goitre is also a common cause. The present review focuses on the diagnostic approach to a child with a hypothyroid, hyperthyroid or euthyroid goitre.

A patient initially presented with an autonomously functioning right thyroid nodule and transient hyperthyroidism which lasted for a few months. Several months after resolution of thyrotoxicosis, the patient had a recurrent episode of hyperthyroidism and was found to have a left hot nodule. The right hyperfunctioning nodule had become cold on scintigraphy, and its aspiration revealed haemorrhagic fluid suggesting haemorrhagic infarction as the mechanism of resolution of the first episode of hyperthyroidism. Again following resolution of the second episode of hyperthyroidism, the left hot nodule also became hypofunctioning on scintigraphy indicating that the spontaneous restoration to euthyroidism was secondary to infarction. Recurrent hyperthyroidism and resolution due to nodular infarction in a patient with a nodular goitre may mimic the more common causes of transient thyrotoxicosis and should be considered in the differential diagnosis of goitrous hyperthyroidism.

Images

Aim

To assess iodine supply and follow thyroid epidemiology for ten years after an iodine increase from 10 to 25 mg of potassium iodide per kilogram of salt in 1999.

Methods

In 2002 and 2003, we determined the thyroid size by palpation and ultrasound and measured urinary iodine concentration (UIC) in 676 schoolchildren from 34 schools throughout Slovenia. From 1999 to 2009, we followed the incidence of diffuse and nodular goiter, thyroid autonomy, Graves’ disease, and Hashimoto’s thyroiditis among adults in the stable catchment area of the University Medical Centre Ljubljana with 1 000 000 inhabitants.

Results

In children, only 1% had a goiter grade 2 (visible and palpable thyroid gland), median thyroid volume was 5.8 mL, and median UIC was 148 µg/L. In adults, the incidence of diffuse goiter and thyroid autonomy decreased significantly (2009 vs 1999, rate ratio [RR], 0.16; 95% confidence interval [CI], 0.12-0.21 and RR, 0.73; 95% CI, 0.62-0.86, respectively), with a lower incidence in younger participants in 2009 (P < 0.001). The incidence of multinodular goiter and solitary nodule increased (2009 vs 1999, RR, 1.55; 95% CI, 1.35-1.79 and RR, 1.72; 95% CI, 1.49-1.99, respectively). No long-term changes were observed for Graves’ disease (2009 vs 1999, RR, 0.95; 95% CI, 0.81-1.13), while the incidence of Hashimoto’s thyroiditis increased strongly (2009 vs 1999, RR, 1.86; 95% CI, 1.64-2.12).

Conclusions

The change from mildly deficient to sufficient iodine supply was associated with a marked change in the incidence of thyroid epidemiology – a significant decline in the incidence of diffuse goiter and thyroid autonomy and a marked increase in the incidence of Hashimoto’s thyroiditis.

Background

Both insufficient and excess iodine may produce thyroid disease. After salt iodization in China, the median urine iodine concentration (UIC) of children aged 8–10 years appeared adequate. However, it is unknown whether dietary changes due to rapid economic development in Shanghai have affected whole population iodine nutrition.

Objective

To assess dietary iodine intake, UIC and the prevalence of thyroid disease in the general population of Shanghai.

Design

A cross-sectional survey was conducted with general participants aged 5–69 years (n = 7,904) plus pregnant and lactating women (n = 380 each) selected by stratified multistage sampling. The iodine concentrations in their salt, drinking water and urine were measured. Daily iodine intake was estimated using the total diet study approach. Serum thyroid hormone concentrations and thyroid-related antibodies were measured and thyroid ultrasonography was performed.

Results

The median iodine concentration in salt was 29.5 mg/kg, and 12.8 µg/L in drinking water. Iodized salt, used by 95.3% of participants, contributed 63.5% of total dietary iodine. Estimated daily iodine intake was 225.96 µg. The median UIC of general participants was 146.7 µg/L; UIC <100 µg/L (iodine insufficiency) was seen in 28.6%; UIC >300 µg/L (iodine excess) in 10.1%. Pregnant women had a median UIC of 135.9 µg/L, with UIC <150 µg/L in 55.4%. Thyroid nodules and subclinical hypothyroidism were found in 27.44% and 9.17%, respectively.

Conclusions

According to published criteria, the current dietary iodine intake in Shanghai was generally sufficient and safe, but insufficient in pregnant women. Thyroid nodules and subclinical hypothyroidism were the commonest thyroid diseases identified.

Plasma calcitonin (CT) was measured in the basal state and/or during provocative tests of hormone secretion in 11 children with congenital non-goitrous cretinism (CNC), in 1 girl with a lingual thyroid, and in 11 normal children. Basal and stimulated CT concentrations were significantly lower in the patients with CNC than in the normal subjects. Mean basal CT (+/- SE) was 41 +/- 4 pg/ml in the normal children, 24 +/- 3 pg/ml in the children with CNC, and 20 +/- 2 pg/ml in the patient with the lingual thyroid. The mean incremental CT responses to calcium infusion were 7.0 +/- 2 pg/ml in the children with CNC, 6.0 pg/ml in the patient with the lingual thyroid, and 146 +/- 47 pg/ml in the normal children. The children with CNC also demonstrated a significant delay in the return of the total serum calcium to basal level after the calcium infusion. The mean incremental CT response after infusion of pentagastrin was 7.6 +/- 2 pg/ml in the children with CNC, 10.0 pg/ml in the child with the lingual thyroid, and 34.4 +/- 11 pg/ml in the normal children. These data indicate that CT deficiency is present in children with CNC and suggest that the deficiency is a consequence of the defective embryologic development of the thyroid gland.

OBJECTIVE: To determine how iodine deficiency and endemic goitre disappeared in Britain. DESIGN: Review of surveys of endemic goitre and iodine nutrition. MAIN RESULTS: Endemic goitre was widespread in Britain but has declined, most notably since the 1960's. Its disappearance was probably due to changes in farming practice, especially iodine supplementation in dairy herds which has resulted in iodine contamination of milk and dairy produce. CONCLUSIONS: Although iodization of dairy herds offers an indirect method of counteracting iodine deficiency, it is haphazard and there should be careful and continuous monitoring of iodine intakes in the population.

Iodine goitre and hypothyroidism in 5 newborn infants in an intensive care unit were induced by cutaneous absorption of iodine, after numerous skin applications of iodine alcohol. The infant's skin permeability allows severe iodine overloading of the thyroid, resulting in goitre and hypothyroidism. Ioduria should always be sought in a newborn infant showing hypothyroidism. Iodine should not be used as a skin disinfectant in young infants.

Screening for iron deficiency was offered to 485 pre-school children in one practice. A questionnaire asking for details of the child's birth, diet, medical history and social status was sent to all the families of these children. Three hundred and eleven children (64% of the total) had blood samples taken for haemoglobin concentration, mean corpuscular volume and serum ferritin levels. Fifty four of the children (17%) were iron deficient (serum ferritin less than 10 micrograms l-1 or mean corpuscular volume less than 75 fl), while 10 (3%) had iron deficiency anaemia (haemoglobin level less than 10.5 g dl-1). The prevalence of iron deficiency and iron deficiency anaemia were not significantly associated with any social class. However, there was a higher prevalence among social class 3 children than children from other social classes, 29% of them having covert iron deficiency, while 6% were frankly anaemic. As there are no ethnic minorities in the practice, dietary inadequacy was likely to be the main cause of iron deficiency. After receiving iron supplements for up to three months, all the children who were iron deficient or anaemic and attended for follow up had normalized blood values. In view of the high prevalence of iron deficiency throughout the social classes, and its association with developmental delay and behavioural disorders, screening will be offered to all children when they attend for measles, mumps and rubella immunization, and those who do not attend will be followed up.

Background

In 1997 a currently obligatory model of iodine prophylaxis, based on mandatory iodization of household salt with 30 mg KI/kg, was introduced. The aim of our study was to assess the iodine intake among school-age children living in Opoczno in 3 subsequent time points – in 1994, before establishment of currently operating model of iodine prophylaxis, in 1999 – 2 years after implementation of iodine prophylaxis and in 2010, – 14 years after its implementation.

Methods

We assessed goitre incidence and urine iodine concentration (UIC) in 104 children in 1994, 207 children in 1999 and 174 children in 2012. Age of examined children ranged from 6 to 15 years. The thyroid volumes evaluated by ultrasound were compared to reference values for thyroid volume proposed by Zimmermann at al. Moreover, we have introduced a new index – V/BSA ratio (comparison of thyroid volume to the body surface area), which to our belief allows for more accurate assessment of thyroid volume.

Results

The median of UICs was 45.5 μg/L (1994), 101.1 μg/L (1999) and 100.6 μg/L (2010). The distribution of obtained results has changed as well – iodine concentrations below 50 μg/L were present in 59.1% children in 1994, in 12.6% children – in 1999 and in 7.1% children – in 2010.

Although a significant decrease in goitre incidence with regard to age – 92.6% (1994) vs 18.5% (1999) and 15.8% (2010), as well as with regard to BSA – 95.4% (1994) vs 15.2% (1999) and 11.6% (2010) was observed, it still points to the iodine deficiency, which is in contradiction with UICs as they are within normal limits. V/BSA ratio avoids such discrepancy. The values of ratio V/BSA were higher in 1994 (7.079 ± 2.775) than in 1999 (2.935 ± 1.112) (p<0.05) and in 2010 (2.846 ± 1.029) (p<0.05).

Conclusions

Hitherto model of iodine prophylaxis has proved to be effective in eliminating the iodine deficiency. The iodine intake is now more even, homogenous, which translates into smaller scatter of UICs and less percentage of children, in whom UIC is less than 50 μg/L. However, the iodine intake only slightly exceeds the recommended values, so median of UICs oscillates around the lower limit of references values.

Of 330 patients given lithium for recurrent manic-depressive disorder 12 developed goitre after treatment periods of five months to two years. All the patients remained clinically euthyroid. Pressure symptoms necessitated subtotal thyroidectomy in two patients. In 9 out of 10 patients with goitre, and in two out of seven without goitre study with radioactive iodine showed abnormal findings in iodine metabolism. Discontinuance of lithium led to disappearance of goitres, while thyroid metabolism returned to normal. Thyroxine or desiccated thyroid produced shrinkage of the gland in spite of continued lithium medication.

Hyperplastic goitre was observed in seven newborn foals. Several were weak at birth and died in the first 48 hours of life. Only one foal had myxedema and only three of the seven had obvious enlargement of the thyroid at necropsy. It is suggested that the goitre observed was caused by a dietary deficiency of iodine.

Images