Animals in Iodine Deficiency or Sulfadimethoxine Models of Thyroid Damage Are Differently Affected by the Consumption of Brassica Sprouts.

The study was primarily aimed at investigating the effect of brassica sprout consumption, namely rutabaga (Brassica napus L. var. napobrassica) sprouts (R) generally recognized as antithyroid agent due to its goitrogenic substance content, on hematological, biochemical, and immunological parameters in rats. Sprouts were tested alone and in a combination with other antithyroid factors, such as iodine deficiency (RDI) and sulfadimethoxine (RS). The expression of the heme oxygenase-1 (HO-1) gene in the thyroid as a stress-inducible protein was determined. The thermographic analysis was also estimated. The intake of rutabaga sprouts by healthy rats did not reveal any significant, harmful effect on the thyroid function. Both body temperature and expression of HO-1 remained unchanged in response to the consumed sprouts. In animals with hypothyroidism, rutabaga sprouts enhanced the negative effect of iodine deficiency or sulfadimethoxine ingestion on the organism by increasing the WBC (RDI), TNF-α (RS), creatinine (RS), and triglyceride (RDI and RS) levels, as well as decreasing PLT (RS) level. Moreover, rutabaga sprout consumption by rats with iodine deficiency and sulfadimethoxine decreased their body temperature. Additionally, the concomitant administration of sprouts and iodine depletion significantly reduced the expression of HO-1 in the thyroid. The results may prove useful in confirming rutabaga sprout consumption to be safe, though the seeds of this vegetable provide a well-known antithyroid agent. Our results have shown that rutabaga sprout consumption may be also a factor that enhances the negative clinical features only when combined with iodine deficiency and sulfadimethoxine ingestion.

Continuously sustained elimination of iodine deficiency: a quarter of a century success in the Islamic Republic of Iran.

BACKGROUND: Iodine deficiency and related disorders were very common in Iran prior to 1996, when universal salt iodization (USI) was implemented and in 2000 Iran was declared iodine deficiency disorders (IDD) free. The aim of this study was to evaluate the adequacy of iodine intake by Iranian households in all 30 provinces of Iran, a quarter of a century after the intervention. METHODS: A total of 18,000 school-aged children (8-10 years with mean 8.7 ± 1 year) were included in this study. Urine samples were collected from all children for measurement of urinary iodine excretion and 1800, 210 and 3000 salt samples were randomly collected from the family kitchen, production site of 73 salt factories and distribution circles of 30 provinces, respectively. RESULTS: The median urinary iodine concentration (UIC) of participants was 161 µg/L. The proportion of children with UIC of, 20-49, 50-99 and ≥ 100 µg/L were 10.3, 15.9 and 73.7%, respectively. The mean (± SD) and median salt iodine values were 28.2 (± 12.6) and 31.7 ppm, at the production site, and 31.5 (± 13.6) and 29.6 ppm at the distribution circles, respectively. About 80% of factory salts had more than 20 ppm iodine. 98% of households consumed iodized salt, 80% had appropriate salt storage, and 83% of the household salts contained ≥ 20 ppm. CONCLUSIONS: Based on the results of this study, Iranian populations are consuming adequate iodine. The well-maintained and monitored USI program has improved the dietary iodine intakes of the population, and the country has achieved all criteria of a well-controlled IDD program.

Iodine deficiency disorders after a decade of universal salt iodization in a severe iodine deficiency region in China.

BACKGROUND & OBJECTIVE: Universal salt iodization (USI) was implemented in all counties of China in 1995. This study was undertaken to assess the status of iodine deficiency disorders control and prevention after 10 years of implementation of USI in a severe iodine deficiency region in China. METHODS: Thirty primary school were selected in Gansu province utilizing cluster sampling methodology for the years 1995 and 2005. In each selected school, 40 children aged 8-10 yr were randomly selected for thyroid and IQ examination, and urinary samples were collected from 12. On the spot casual urine samples and salt samples were collected from a subset of children included in the study. In 2005, casual urine samples were also collected from 50 pregnant and lactating women in each cluster. Effect of health education was studied by a combination method of giving questionnaires to and observing students and families. RESULTS: The total goiter rates (TGR) were found to be 13.5 and 38.7 per cent in 2005 and 1995 respectively. The medians urinary iodine excretion levels of children were 191.8 and 119.9 mICROg/l in 2005 and 1995. The median urinary iodine excretion level of women was 161.9 mICROg/l. The mean intelligence quotient (IQ) was 96.9 in 2005 significantly more than that in 1997 (P<0.05). The health education pass rate of children and women were 21.1 and 51.1 per cent respectively. INTERPRETATION & CONCLUSION: After ten years of universal salt iodization (USI), iodine nutrition of people improved and the current iodine nutrition status of population was adequate. Decrease in TGR and increase in IQ showed that IDD control and prevention had made great progress through ten years USI, salt iodization played the key role in IDD control and prevention for sustained elimination of IDD, the programme of USI and other measures like health education should be persisted and enforced.

Sustainability of a well-monitored salt iodization program in Iran: marked reduction in goiter prevalence and eventual normalization of urinary iodine concentrations without alteration in iodine content of salt.

OBJECTIVE: Two yr after legislation of salt iodization of 40 parts per million (ppm) in 1994, goiter was still endemic and urinary iodine concentration (UIC) remained elevated in many provinces of Iran. Goiter prevalence and UIC were compared 2 and 7 yr after sustained consumption of uniformly iodized salt by Iranian households. METHODS: Schoolchildren (7-10 yr) of all provinces were randomly selected by cluster sampling from December 2000 to June 2001. Goiter rate, UIC, and household salt iodine values were compared to those in 1996. Factory salt iodine was also compared in 2001 vs 1996. Ultrasonographically determined thyroid volumes of 7-10 yr old children were compared in 2001 vs 1999. RESULTS: In 2001 (no.=33600) vs 1996 (no.=36178), total, grade 1, and grade 2 goiter rates were 13.9 vs 53.8%, 11.0 vs 44.8%, and 2.9 vs 9.0%, respectively (p<0.0001). Weighted total goiter rate was 9.8% in 2001. Median (range) UIC in 2001 (no.=3329) was 165 (18-499) microg/l and in 1996 (no.=2917) was 205 (10-2300) microg/l (p<0.0001). In 2001 vs 1996, mean+/-SD for iodine salt content was 32.7+/-10.1 vs 33.0+/-10.2 ppm (p=0.68) in households and was 33.2+/-13.4 and 33.8+/-13.2 ppm (p=0.57) in factories, respectively. Among 7-10 yr old children in 2001 (no.=400) vs 1999 (no.=396), only 7-yr-old children in 2001 (the only group with probably no history of iodine deficiency) showed significant smaller thyroid volumes by ultrasonography compared to those in 1999. CONCLUSIONS: After 7 yr of optimized iodized-salt supplementation in Iran, adequate UIC values and marked reduction in goiter rate have been achieved.

Urinary iodine excretion and antiperoxidase enzyme antibody in goitrous and healthy primary school children of Arak, Iran.

OBJECTIVE: To determine urinary iodine excretion (UIE) and antiperoxidase enzyme antibody (anti-TPO Ab) in primary school-age children living in Arak, Iran, in 2005, after 10 yr of iodized salt distribution in an effort to ameliorate iodine deficiency. METHODS: Through an observational, case-control study and by means of satisfied sampling, 6520 primary school children were examined for goiter, and then 193 goiterous children (case) and 151 healthy (control) children were assessed as representative samples for thyroid function tests, antiperoxidase antibody, and urinary iodine excretion. Normal values of anti-TPO Ab were <40 U/ml and high values >75 U/ml. Normal values of urinary iodine concentration were > or =10.0 microg/dl, and severe iodine deficiency were <2 microg/dl. The data were analyzed and compared by the Chi- Square tests and Mann-Whitney U in SPSS software; p-values <0.05 were considered statistically significant. RESULTS: Total mean prevalence of goiter was 5.2%, ranging from 3.6 to 6.4% in different schools. The prevalence of goiter increased with age; it was 3% in children aged 6-7 yr and 6.3% in children aged 11 yr (p<0.001). Mean iodine urinary concentration was 16.36 microg/dl (+/-1.58). No difference was seen between the mean urinary iodine in girls (17.30+/-3.80 micorg/dl) and boys (15.72+/-2.72 microg/dl). No difference was seen between the mean urinary iodine in goiterous and healthy school children (17.4+/-3.7 microg/dl vs 15.3+/-3.18 microg/dl, p=0.78). About 49.5% of school children had UIE<10 microg/dl and 28% had UIE<5 microg/dl. High levels of anti-TPO Ab were found in 21 school children (18 goiterous vs 3 healthy children, p=0.01) resulting in a total prevalence of 6.1%. In females, the prevalence was 1.3 times higher than in males (male:female ratio 3/4). Thirteen out of 21 (62%) children with positive antibodies had significant goiter (grade 2), and 5 (24%) had small goiter (grade 1), whereas only 3 children (14%) had normal thyroid size (p=0.001). CONCLUSION: If urinary iodine concentration is considered an index of total body iodine content, this study demonstrated that prolonged iodized salt intake has minimized the occurrence of iodine deficiency goiter and now autoimmune thyroid enlargement is one cause for continuous goiter in primary school children, although there are unknown etiologies that need to be considered in further studies.

Accelerating progress on salt iodisation in Sudan: time for action.

This paper uses a public health approach to examine briefly: (a) the progress of universal salt iodisation (USI) in Sudan; (b) the roles of the main actors involved; and (c) the main issues around accelerating USI. The literature, especially that coming from the UN agencies, is analysed and experiences from the recently revitalised USI programme, and related relevant meetings, are distilled. In Sudan the prevalence of goitre is 22 per cent. It is assumed that productivity among the people affected is reduced by 5-25 per cent. Little apparent progress has been made with USI. The Government of Sudan, UN multilateral agencies, international consultative groups, bilateral agencies, global and national non-governmental organisations and, increasingly, the private sector must work together to find innovative approaches to increase awareness of the broader social, public health and nutritional contexts, and to advocate for increased national nd international funding.

Effects of diuretics on iodine uptake in non-toxic goitre: comparison with low-iodine diet.

Low-iodine diet has been employed to achieve iodine depletion prior to radioiodine (RI) therapy. However, treatment with diuretics may be more effective than low-iodine diet in causing iodine depletion and subsequent increase in RI uptake by the thyroid. Fifty-five patients with non-toxic goitre were given 0.20 MBq RI p.o. on the first day of the study and thyroid uptake was measured. In 15 patients, a low-iodine diet was started and continued for 14 days. The remaining 40 patients received furosemide 40 mg/day orally for 5 days with an unrestricted diet. On the 15th day of the study, all patients were given 0.20 MBq RI p.o. and thyroid RI uptake was measured again. Additionally, 24-h urinary iodine excretion and RI clearance were measured on the 1st and 6th days in 21 patients from the furosemide group and on the 1st and 15th days in eight patients from the diet group. Furosemide administration led to a 58.40% increase in iodine uptake over the baseline value, which was significantly higher than the increase caused by low-iodine diet (17.22%) ( P<0.0001). Urinary excretion of RI decreased in both groups similarly (furosemide, 29.45%; low-iodine diet, 21.06%; P=0.33). Iodine clearance also decreased in each group similarly (10.61% vs 7.53%, P=0.53). Treatment with furosemide prior to administration of RI increases the uptake of RI by the thyroid more effectively than does low-iodine diet.

Difference in goiter rates between regular and occasional users of iodized salt in Mongolia.

In Mongolia many households use iodized salt only occasionally. We investigated whether the occasional use of iodized salt had an impact on the reduction of goiter size. We examined 685 children (8-11 years old) in five groups of households that (1) used iodized salt regularly, (2) used more than 10 kg of iodized salt annually, (3) used 6 to 10 kg annually, (4) used less than 6 kg annually, (5) and regularly used noniodized salt. The prevalence of goiter as determined by ultrasound in these five groups was 31.1%, 30.3%, 40.6%, 52.1%, 56.6%, respectively. There was no difference between goiter rates among the first three groups, but these groups had significantly lower rates than the last two groups. We concluded that annual use of more than 6 kg of iodized salt, preferably more than 10 kg, by a household had a beneficial effect on the rate of goiter. In addition, the possibility was suggested that households that consumed only iodized salt consumed less salt than other households.

Randomized clinical trial comparing different iodine interventions in school children.

OBJECTIVE: The purpose of this trial was to compare three different iodine interventions. DESIGN: School children aged 8-10 years were randomized into one of three groups: group A was provided with iodized salt by researchers with an iodine concentration of 25 ppm; group B purchased iodized salt from the market; and group C was similar to group B with the exception that they were given iodized oil capsules containing 400 mg iodine at the beginning of the study. Salt iodine content was measured bimonthly for 18 months and indicators of iodine deficiency were measured at baseline and 6, 9, 12 and 18 months after randomization. RESULTS: The prevalence of abnormal thyroid volumes, based on the World Health Organization (WHO) body surface area reference >97th percentile, was 18% at baseline and declined to less than 5% by 12 months in groups A and C, and to 9% after 18 months in group B. Results for goitre by palpation were similar. The median urinary iodine was 94 microg l(-1) at baseline and increased in all groups to > 200 microg l(-1) at the 6-month follow-up. CONCLUSIONS: In this population of school children with initially a low to moderate level of iodine deficiency, the group receiving salt with 25 ppm (group A) was not iodine deficient on all indicators after 18 months of study. When the iodine content of the salt varied, such as in group B, by 18 months thyroid sizes had not yet achieved normal status.

The use of sugar as a vehicle for iodine fortification in endemic iodine deficiency.

The use of sugar as a vehicle for iodine supplementation was explored in a study of iodine deficiency in the Sudan. A survey of sugar consumption was conducted and established a widespread and uniform intake of sugar in all ages with no differences among socio-economic groups. The daily intake among adults varied from 48 g to 78 g as examined in five different geographical areas in the country. Iodinated sugar was produced by addition to sugar solution prior to crystallisation in an evapocrystallizer or sprayed on the conveyor of cured sugar before it entered the dryers. Subsequently, the iodinated sugar was given to members of 18 and 60 families in a mildly (urinary iodine < 5.1 micrograms/dl) and moderately (urinary iodine < 3 micrograms/dl) iodine deficient areas, respectively, over a 1-month and a 6-month period, respectively. In both tests, improvements were recorded, i.e. the rates of goitre decreased, urinary iodine levels increased significantly (from 5.1 to 14.4 micrograms/dl and from 3 to 9.8 micrograms/dl, respectively) and thyroid hormones values rose. No side effects were noted. The results indicate that fortification of sugar with iodine may serve as a new alternative approach in attempts to eradicate iodine deficiency related disorders in endemic areas.

[Experimental study on the antigoiter effect of high casein nutrition].

In this experiment, goiter was successfully induced in rat with MMI, and the antigoiter effect of 25% and 50% casein diet was observed. The results showed that the diet with 50% casein is more effective than that with 25% casein in counteracting MMI and preventing goiter in rat. The antigoiter mechanisms of high protein nutrition might be as follows: Protecting the mechanism of thyroid iodine transportation through the follicular cell, and therefore accelerating thyroid iodine metabolism; Relieving thyroid peroxidase (TPO) from the inhibitive effect of MMI and facilitating thyroid hormone synthesis; Coordinating the function of hypothalamus-pituitary-TSH-thyroid axis and protecting the wholeness of thyroid cell and thus avoiding the occurrence of pathological changes.

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.

Thyroid function of subjects with goitre and cretinism in an endemic goitre area of rural China after use of iodized salt.

Endemic goitre and cretinism are still a public health problem in China. An epidemiological survey showed that about 5% of the inhabitants in Daxin village, Henan province, had goitre or cretinism after an iodized salt prevention programme had been carried out for two decades. The main food for the inhabitants of this area has an iodine content less than 30 nmol/kg and the water for cooking and drinking has an iodine concentration between 7-12 nmol/l. We studied thyroid function in subjects of this village. There were 42 with grade 0 goitre (males 29, females 13), 42 grade I (males 23, females 19), 27 grade II (males 9, females 18), 31 grade III (males 14, females 17) and 34 cretinism patients (males 30, females 4) diagnosed and classified according to WHO criteria. Serum T4, free T4, T3, free T3, T3 uptake, TSH and thyroglobulin were measured in these subjects. The patients with goitre or cretinism had significantly decreased serum free T4 and increased serum T3 and free T3 levels compared with those of controls. Thyroid size was positively correlated with age and serum thyroglobulin concentrations. Serum thyroglobulin was significantly increased even in the grade 0 goitre subjects. The percentages of subjects with serum free T4 less than 12 nmol/l, T3 greater than 2.5 nmol/l, free T3 greater than 5.2 pmol/l, TSH greater than 3.5 mU/l, T3/T4 ratio greater than 0.03 and free T3/free T4 ratio greater than 0.36 were significantly higher among goitre and cretinism patients than among controls. The data suggest that there is partial compensation for a marginal deficiency of iodine in the inhabitants of this village.

Antigoitrogenic effect of casein.

Epidemiological findings from the city of Cali, Colombia, support the hypothesis that water supply and iodine intake are not the only dietary factors which influence the magnitude of the goitre endemia. Experiments were conducted in rats to determine whether casein has a counteracting effect on the goitrogenic and antithyroid activities of methimazole (MMI) and goitrogenic water extracts (GWE) from the endemic area of the Cauca Valley. Female albino rats (Charles River, DC strain) 100-110 g initial weight, receiving 12 mug of iodine daily, were divided into three groups annd put on special diets: protein-free, 8 % casein, or 60 % casein, respectively. Each group (24 rats) was then divided into three subgroups. Subgroup one received goitrogen-free water and was used as a control. Subgroup two was administered MMI, 50 mug/day/rat. Subgroup three was given per animal a daily amount of GWE equivalent in antithyroid potency to 50 mug of MMI. At 77 days, the thyroid glands were studied for weight, 131I uptake, and 127I concentration. Animals on the protein-free diet showed significantly (P less than 0.05 - less than 0.01) larger thyroid glands per 100 g body weight and lower thyroidal 4 h 131I uptake and 127I-concentrations than rats on casein diets. These differences were significantly increased (P less than 0.01) by the administration of MMI and GWE. All the effects were completely reversed by the 60 % casein diet showing no differences between control rats and those on MMI or GWE. Rats on 8 % casein showed intermediate values between those of animals on protein-free and 60 % casein diets; differences were still present between the control as against the MMI or GWE groups, The results indicate that under these experimental conditions, a poor-protein diet impairs the thyroidal transport of iodine, decreases its concentration in the thyroid and is accompanied by an enlargement of the gland. Under these circumstances, the action of thiourea-like antithyroid agents is enhanced. The administration of protein reverses these alterations and decreases the action of such antithyroid agents. Whether the changes observed are due to a direct action of casein on the thyroid and/or to effects of malnutrition on the metabolism of antithyroid compounds remains to be determined.