scholarly journals Selenium and goiter prevalence in borderline iodine sufficiency

2006 ◽  
Vol 155 (6) ◽  
pp. 807-812 ◽  
Author(s):  
Volker F H Brauer ◽  
Ulrich Schweizer ◽  
Josef Köhrle ◽  
Ralf Paschke

Design: Selenium (Se) is required for the biosynthesis of selenocysteine-containing proteins. Several selenoenzymes, e.g. glutathione peroxidases and thioredoxin reductases, are expressed in the thyroid. Selenoenzymes of the deiodinase family regulate the levels of thyroid hormones. For clinical investigators, it is difficult to determine the role of Se in the etiology of (nodular-)goiter, because there are considerable variations of Se concentrations in different populations as reflected by dietary habits, bioavailability of Se compounds, and racial differences. Moreover, most previous clinical trials which investigated the influence of Se on thyroid volume harbored a bias due to the coexistence of severe iodine deficiency in the study populations. Methods: Therefore, we investigated the influence of Se on thyroid volume in an area with borderline iodine sufficiency. First, we investigated randomly selected probands for urinary iodine (UI) and creatinine excretion in spot urine samples and determined the prevalence of goiter and thyroid nodules by high-resolution ultrasonography. After this, we determined urinary Se excretion (USe) in probands with goiter as well as in matched probands without goiter. Adjustments between the two compared groups were made for age, gender, history of thyroid disorders, smoking, and UI excretion. Results: The mean USe and UI rates of all 172 probands were 24 μg Se/l or 27 μg Se/g creatinine and 96 μg I/l or 113 μg I/g creatinine indicating borderline selenium (20–200 μg/l) and iodine (100–200 μg/l) sufficiency of the study population. Probands with goiter (n=89) showed significantly higher USe levels than probands with normal thyroid volume (n=83; P < 0.05). USe rates were not influenced by present smoking or pregnancy. Conclusions: In our investigation, USe was not an independent risk factor for the development of goiter. The higher USe in probands with goiter in comparison with probands with normal thyroid volume is most likely a coincidence. Se does not significantly influence thyroid volume in borderline iodine sufficiency because the iodine status is most likely the more important determinant.

2006 ◽  
Vol 154 (2) ◽  
pp. 229-235 ◽  
Author(s):  
V F H Brauer ◽  
H Below ◽  
A Kramer ◽  
D Führer ◽  
R Paschke

Objective: Thiocyanate (SCN−) has concentration dependent antithyroid properties and a role in the etiology of goiter has been suggested in several studies. In 1991 an epidemiological survey conducted in the region of Halle/Leipzig (Saxony), an area with significant air pollution, suggested an inverse relationship between urinary iodine (I−)/SCN− excretion and goiter prevalence. 10 years later, we reinvestigated the same industrial area to clarify if the situation has changed after the elimination of most industrial waste products and moreover, if SCN− excretion levels alone or in combination with air pollution or smoking as a SCN− source are critical for thyroid function. Design and methods: We investigated a cohort of 708 probands for I−, SCN− and creatinine excretion in spot urine samples and determined the prevalence of goiter and thyroid nodules by high resolution ultrasonography. Results: Probands with goiter (n = 79, 11%) had significantly higher urinary SCN− excretions than probands without (3.9 ± 2.8 vs 3.1 ± 3.4 mg SCN−/g creatinine) and significantly lower urinary I−/SCN− ratios than patients without thyroid disorders (41 ± 38 vs 61 ± 71 μg I−/mg SCN−/l). Mean urinary I− excretions were not different between probands with or without goiter. Smokers showed significantly elevated urinary SCN−/creatinine ratios in comparison to non-smokers (4.3 ± 4.3 vs 2.4 ± 2.1 mg SCN−/g creatinine). ANOVA revealed a prediction of thyroid volume through age (P < 0.001), gender (P < 0.001), body weight (P < 0.05) and smoking (P < 0.05). Conclusions: In our investigation, age, gender and smoking (raising SCN− levels by CN− inhalation) were predictive for thyroid volume and the urinary I−/SCN− ratios were able to detect probands with an increased risk of developing goiter in contrast to urinary I− excretion levels alone. These data suggest, that in an era and area of decreased cyanide pollution, SCN− may remain a cofactor in the multifactorial aetiology of goiter.


Nutrients ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 11
Author(s):  
Conte ◽  
Comina ◽  
Monti ◽  
Sidoti ◽  
Vannozzi ◽  
...  

Italy is considered a mildly iodine-deficient country. The aim of this study was to evaluate the iodine status of a cohort of adults living in Liguria after the 2005 salt iodization program. We searched all medical records of patients examined in two endocrine outpatient clinics in Genoa and Savona for data on urinary iodine. Subjects were under evaluation for thyroid diseases. Information on the type of salt used was found in few clinical records. Iodized salt use was reported in 29%, 20%, and 13% of records of people living in Genoa districts, the Savona district and nearby districts, respectively. The average urinary iodine concentration was 112.9 ± 62.3 µg/L (n = 415, median 101.0 µg/L). Non-significant differences (P > 0.05) were found between subjects with (median 103.5 µg/L) and without (median 97.5 µg/L) a thyroid gland, between the periods 2009–2013 (median 105.0 µg/L) and 2014–2018 (median 97.5 µg/L), and between Genoa (median 94.0 µg/L), Savona (median 105.0 µg/L) and the other districts (median 114.5 µg/L). No correlation with age, body mass index, creatinine, free thyroxine, thyroglobulin, levo-thyroxine dosage, or thyroid volume was observed. These data suggest a borderline status of iodine sufficiency in this cohort.


2020 ◽  
Vol 76 (3) ◽  
pp. 165-174
Author(s):  
Wenxing Guo ◽  
Wei Wang ◽  
Ya Jin ◽  
Wen Chen ◽  
Lu Chen ◽  
...  

Objectives: To explore trimester-specific thyroid function changes under different iodine statuses throughout pregnancy. Methods: A cross-sectional study was conducted to assess the pregnancy iodine status, and 2,378 healthy pregnant women covering all 3 trimesters were recruited. Urinary iodine concentration (UIC) was measured by collecting spot urine samples. Blood samples were collected to evaluate thyroid function. Thyroid B-ultrasonography was conducted to measure the thyroid volume (Tvol). Results: The median UIC was 168 μg/L (111–263 μg/L). The UIC, free triiodothyronine (FT3), and free thyroxine (FT4) were significantly decreased as the pregnancy progressed (p < 0.001, p for trend <0.001), while Tvol increased (p < 0.001, p for trend <0.001). Thyrotropin (TSH) was significantly different between the 3 trimesters and showed an upward trend (p < 0.001), but the p for trend was not significant (p for trend = 0.88). After stratification by UIC, there were no significant differences in serum TSH, FT4, or FT3 level between UIC groups. Tvol was significantly higher in the UIC ≥500 μg/L group in the first trimester (β: 2.41, 95% CI: 1.09–3.72, p <0.001), as well as in the 250 ≤ UIC < 500 μg/L group (β: 1.65, 95% CI: 0.61–2.70, p < 0.001) and UIC ≥500 μg/L group (β: 3.35, 95% CI: 1.96–4.74, p < 0.001) in the third trimester. Conclusions: No difference was observed in TSH, FT3, or FT4 among the different iodine status groups throughout pregnancy. Tvol increased as the pregnancy progressed, and it was especially higher in the UIC ≥500 μg/L group in the first and third trimesters.


2018 ◽  
Vol 14 (3) ◽  
pp. 149-155
Author(s):  
Tatiana V. Mokhort ◽  
Sergei V. Petrenko ◽  
Boris Y. Leushev ◽  
Ekaterina V. Fedorenko ◽  
Natalia D. Kolomiets ◽  
...  

Background. Despite the measures taken by the Government of Belarus, the problem of iodine deficiency among the population remains actual. Aims. To determine iodine sufficiency in children and pregnant women living in Belarus. Materials and methods. The study included 873 schoolchildren aged 9–12 years of both sexes, of which 650 children were in regular schools, and the remaining children in boarding schools. A separate group consisted of 700 practically healthy pregnant women (during gestation from 16 to 36 weeks). Questioning, determination of urinary iodine concentration and thyroid volume with ultrasound was carried out. Results. Urine iodine median was 191 µg/L in the 873 children in 16 regions of Belarus. Thyroid volume corresponds to the normative values in children. According to the survey, 81% of households used iodized salt, constantly – 46%. Indicator of iodine sufficiency of 700 pregnant women (median urinary iodine concentration was 121 µg /l) is a non-optimal for this population group. Conclusions. Currently adequate iodine supplementation in school age children has been achieved. The prevalence of thyroid gland diseases caused by iodine deficiency in children decreased significantly. In pregnant women iodine supply is still insufficient.


2001 ◽  
pp. 595-603 ◽  
Author(s):  
WM Wiersinga ◽  
J Podoba ◽  
M Srbecky ◽  
M van Vessem ◽  
HC van Beeren ◽  
...  

BACKGROUND: Iodine deficiency and endemic goiter have been reported in the past in The Netherlands, especially in the southeast. OBJECTIVE: To evaluate iodine intake and thyroid size in Dutch schoolchildren, contrasting those living in a formerly iodine-deficient region in the east (Doetinchem) with those living in an iodine-sufficient region in the west (Amsterdam area). DESIGN: Cross-sectional survey of 937 Dutch schoolchildren aged 6--18 years, of whom 390 lived in the eastern and 547 in the western part of the country. METHODS: Thyroid size was assessed by inspection and palpation as well as by ultrasound. Iodine intake was evaluated by questionnaires on dietary habits and by measurement of urinary iodine concentration. RESULTS: Eastern and western regions were similar with respect to median urinary iodine concentration (15.7 and 15.3 microg/dl, NS, Mann-Whitney U test), goiter prevalence by inspection and palpation (0.8 and 2.6%, P=0.08, chi-squared test), and thyroid volumes. The P97.5 values of thyroid volumes per age and body surface area group were all lower than the corresponding sex-specific normative WHO reference values. Iodized salt was not used by 45.7% of households. Daily bread consumption was five slices by boys and four slices by girls. Weekly milk consumption was 3 liters by boys and 2 liters by girls. Seafish was consumed once monthly. From these figures we calculated a mean daily iodine intake of 171 microg in boys and 143 microg in girls, in good agreement with the measured median urinary concentration of 16.7 microg/dl in boys and 14.5 microg/dl in girls. The sex difference in iodine excretion is fully accounted for by an extra daily consumption of one slice of bread (20 microg I) and one-seventh of a liter of milk (8.3 microg I) by boys. Thyroid volume increases with age, but a steep increase by 41% was observed in girls between 11 and 12 years, and by 55% in boys between 13 and 14 years, coinciding with peak height velocity. Girls have a larger thyroid volume at the ages of 12 and 13 years, but thyroid volume is larger in boys as of the age of 14 years. CONCLUSIONS: (1) Iodine deficiency disorders no longer exist in The Netherlands. (2) Bread consumption remains the main source of dietary iodine in The Netherlands; the contribution of iodized table salt and seafish is limited. (3) The earlier onset of puberty in girls renders their thyroid volume larger than in boys at the age of 12--13 years, but boys have a larger thyroid volume as of the age of 14 years.


2000 ◽  
pp. 37-46 ◽  
Author(s):  
S Brahmbhatt ◽  
RM Brahmbhatt ◽  
SC Boyages

OBJECTIVES: (i) To assess the severity of iodine deficiency disorders (IDD), (ii) to determine the aetiology of IDD in Gujarat, (iii) to identify the best prevalence indicator of IDD, and (iv) to compare thyroid volume (TV) results with the WHO International reference. METHODS: Five hundred and thirty schoolchildren (6-15 years) were studied from two districts (Baroda and Dang) and data were collected on dietary habits and parameters such as height, weight, thyroid size by palpation and ultrasonography, urinary iodine (UI), and blood thyroid stimulating hormone (TSH). Drinking water was analyzed for iodine content and food articles for goitrogens. RESULTS: In Gujarat children median UI (interquartile range)=56 (30-96)microg/l, mean TSH=1.71 +/- 2.10mU/l, goiter by palpatio n = 30%, and median TV = 27.8 (23-35)ml. Females had lower median UI (48 (27-82) microg/l) and higher mean TSH levels (2.0 +/- 2.5mU/l) than males. Applying the WHO ultrasonography reference to Gujarat children resulted in an enlarged TV-for-body surface area in almost 100% of subjects. Ninety-nine percent of females and 95% of males had enlarged TV-for-age. Three to eight times larger TV were seen in all subjects as compared with European children. Dang children were severely malnourished. Flavonoids like vitexin, glucosyl vitexin and apigenin were detected in pearl millet. Apigenin was never identified in pearl millet. Dang district water was lacking in iodine content. CONCLUSIONS: IDD is a severe public health problem in Gujarat. Baroda district is a new pocket of IDD. High amounts of dietary flavonoids in Baroda and Dang districts, and lack of iodine in Dang water, account for IDD. TV measurement by ultrasound is the best prevalence indicator of IDD.


2000 ◽  
Vol 39 (05) ◽  
pp. 133-138 ◽  
Author(s):  
W. Dembowski ◽  
H.-J. Schroth ◽  
K. Klinger ◽  
Th. Rink

Summary Aim of this study is to evaluate new and controversially discussed indications for determining the thyroglobulin (Tg) level in different thyroid diseases to support routine diagnostics. Methods: The following groups were included: 250 healthy subjects without goiter, 50 persons with diffuse goiter, 161 patients with multinodular goiter devoid of functional disorder (108 of them underwent surgery, in 17 cases carcinomas were detected), 60 hyperthyroid patients with autonomously functioning nodular goiter, 150 patients with Hashimoto’s thyroiditis and 30 hyperthyroid patients with Graves’ disease. Results: The upper limit of the normal range of the Tg level was calculated as 30 ng Tg/ml. The evaluation of the collective with diffuse goiter showed that the figure of the Tg level can be expected in a similar magnitude as the thyroid volume in milliliters. Nodular tissue led to far higher Tg values then presumed when considering the respective thyroid volume, with a rather high variance. A formula for a rough prediction of the Tg levels in nodular goiters is described. In ten out of 17 cases with thyroid carcinoma, the Tg was lower than estimated with thyroid and nodular volumes, but two patients showed a Tg exceeding 1000 ng/ml. The collective with functional autonomy had a significantly higher average Tg level than a matched euthyroid group being under suppressive levothyroxine substitution. However, due to the high variance of the Tg values, the autonomy could not consistently be predicted with the Tg level in individual cases. The patients with Hashimoto’s thyroiditis showed slightly decreased Tg levels. In Graves’ disease, a significantly higher average Tg level was observed compared with a matched group with diffuse goiter, but 47% of all Tg values were still in the normal range (< 30 ng/ml). Conclusion: Elevated Tg levels indicate a high probability of thyroid diseases, such as malignancy, autonomy or Graves’ disease. However, as low Tg concentrations cannot exclude the respective disorder, a routine Tg determination seems not to be justified in benign thyroid diseases.


1990 ◽  
Vol 29 (03) ◽  
pp. 113-119
Author(s):  
C. R. Pickardt ◽  
K. Horn ◽  
G. Bechtner ◽  
C. Vaitl ◽  
C. M. Kirsch ◽  
...  

Global TcTU was determined in 568 patients without any specific thyroid drug intake - 54 with normal thyroid, 274 with goitre and euthyroidism and 240 with thyroid autonomy. 57 patients with autonomy and overt hyperthyroidism were the only group with TcTU values significantly higher than normals. Common to all groups was a large scatter of the TcTU values. In 332, the effects of individual iodine supply were studied by measuring the iodine concentration in spot urine samples. There was a significant inverse correlation between the TcTU values and the urinary iodine excretion in the groups of normal thyroids and of goitres with euthyroidism. In the group with autonomy an effect of iodine supply could only be seen in cases of greatly increased urinary iodine excretion, resulting in very low TcTU values. Out of 20 patients with autonomy and iodine contamination, only 4 showed overt hyperthyroidism. The large scatter of TcTU values in all groups may be explained by the persistent iodine deficiency as well as by the frequent exposure to unknown amounts of iodine in patients with thyroid disease. Therefore, the spontaneous TcTU alone cannot identify a small group of patients with autonomy and high risk of iodine-induced hyperthyroidism, from a very large group of patients with goitre.


1993 ◽  
Vol 129 (6) ◽  
pp. 497-500 ◽  
Author(s):  
F Aghini-Lombardi ◽  
A Pinchera ◽  
L Antonangeli ◽  
T Rago ◽  
GF Fenzi ◽  
...  

It is well established that iodine supplementation is effective in correcting iodine deficiency and reducing goiter prevalence. In Italy, legislation has allowed the production of iodized salt since 1972, but its consumption is on a voluntary basis. In the present study, the efficacy of legislative measures that made compulsory the availability of iodized salt in foodstores has been evaluated. Urinary iodine excretion and thyroid size, scored according to Pan American Health Organization recommendations, were determined prior to (1981) and 10 years after (1991) the introduction of legislative measures in the whole schoolchildren population residing in a restricted area of the Tuscan Appennines. Moreover, in 1991, thyroid volume was determined by ultrasonography. In 1981, mean urinary iodine excretion was 47.1±22.4 mg/kg creatinine (0.412 μmol/l) and goiter prevalence was 60%, indicating a moderate iodine deficiency. Eighty of the families subsequently used iodized salt on a regular basis; as a result of this excellent compliance, in 1991 the mean urinary iodine excretion increased to 129.7±73 mg/kg creatinine (1.24 μmol/l) and goiter prevalence dropped to 8.1%. The results of this study underline the effectiveness of iodine prophylaxis in correcting iodine deficiency and abating endemic goiter in schoolchildren, and suggest that implementation of measures that make compulsory the availability of iodized salt in foodstores overcomes the fact that there is no law governing the exclusive production and trading of iodized salt.


2003 ◽  
pp. 103-110 ◽  
Author(s):  
G Mazziotti ◽  
LD Premawardhana ◽  
AB Parkes ◽  
H Adams ◽  
PP Smyth ◽  
...  

OBJECTIVE: To study the evolution of thyroid autoimmunity, in relation to the change in goitre prevalence, during 3 Years of iodine prophylaxis in Sri Lanka. METHODS: Two groups of Sri Lankan schoolgirls between the ages of 10.8 and 17.5 Years were studied in 1998 (401 girls) and 2001 (282 girls). A prospective study was performed in 42 schoolgirls who were thyroid autoantibody (Ab)-positive (+ve) in 1998. Anthropometric measures, urinary iodine excretion (UIE), thyroid Volume, free thyroxine, free tri-iodothyronine, TSH, and thyroglobulin (Tg) and thyroid peroxidase (TPO) Ab were evaluated in all 683 girls. RESULTS: Goitre prevalence was significantly lower in 2001 compared with 1998 related to age (2.9% compared with 20.2%) and body surface area (11.6% compared with 40.8%), although UIE was unchanged. Prevalence of thyroid Ab in 2001 was also lower (23.4% compared with 49.9%); among those with the Ab, 34.8% had TgAb alone and 46.9% had a combination of TgAb+TPOAb, compared with 82.0% TgAb alone in 1998. In 2001, subclinical hypothyroidism was more frequent in Ab+ve (6.3%) than Ab-negative girls (1.0%). A cohort of 42 Ab+ve schoolgirls in 1998 (34 with TgAb alone, eight with TgAb+TPOAb) were evaluated again in 2001. Only 10 of them (23.8%) remained Ab+ve (mostly TPOAb+/-TgAb) in 2001. CONCLUSIONS: This study demonstrates that: (1) in 2001, goitre prevalence and thyroid autoimmunity rates were significantly lower than in 1998; (2) the pattern of thyroid Ab was different in the two surveys; (3) in 2001 alone, the occurrence of hypothyroidism was correlated with the presence of thyroid autoimmunity. These results indicate an evolution of thyroid autoimmune markers during the course of iodine prophylaxis, which has not been described before.


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