Iodine metabolism and indicators of iodine status

2015 ◽  
pp. 539-559
Keyword(s):  
Iodine Status ◽  
Iodine Metabolism

scholarly journals Iodine and Pregnancy

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Christina Yarrington ◽  
Elizabeth N. Pearce
Keyword(s):  
Thyroid Hormone ◽  
Pregnant Women ◽  
Thyroid Function ◽  
Environmental Contaminants ◽  
Iodine Status ◽  
Nutritional Recommendations ◽  
Iodine Metabolism ◽  
The Impact ◽  
In Pregnancy

Iodine is a necessary element for the production of thyroid hormone. We will review the impact of dietary iodine status on thyroid function in pregnancy. We will discuss iodine metabolism, homeostasis, and nutritional recommendations for pregnancy. We will also discuss the possible effects of environmental contaminants on iodine utilization in pregnant women.

scholarly journals Iodine Status, Thyroid Function, and Birthweight: A Complex Relationship in High-Risk Pregnancies

2020 ◽  
Vol 9 (1) ◽  
pp. 177 ◽  
Author(s):  
Inés Velasco ◽  
Mar Sánchez-Gila ◽  
Sebastián Manzanares ◽  
Peter Taylor ◽  
Eduardo García-Fuentes
Keyword(s):  
High Risk ◽  
Amniotic Fluid ◽  
Cord Blood ◽  
Thyroid Function ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Free Thyroxine ◽  
Urinary Iodine Concentration ◽  
Iodine Status ◽  
Iodine Metabolism

(1) Background: The consequences of iodine deficiency and/or thyroid dysfunction during pregnancy have been extensively studied, emphasizing on infant neurodevelopment. However, the available information about the relationship between iodine, thyroid hormones, and fetal growth in high-risk pregnancies is limited. We aim to investigate if iodine metabolism and/or thyroid parameters can be affected by adverse antenatal/perinatal conditions. (2) Methods: A cross-sectional study examined differences in iodine status, thyroid function, and birthweight between high-risk (HR group; n = 108)) and low-risk pregnancies (LR group; n = 233) at the time of birth. Urinary iodine concentration (UIC), iodine levels in amniotic fluid, and thyroid parameters [thyroid-stimulating hormone (TSH), free thyroxine (FT4)] were measured in mother–baby pairs. (3) Results: There were significant differences between HR and LR groups, free thyroxine (FT4) concentration in cord blood was significantly higher in the LR group compared with HR pregnancies (17.06 pmol/L vs. 15.30 pmol/L, respectively; p < 0.001), meanwhile iodine concentration in amniotic fluid was significantly lower (13.11 µg/L vs. 19.65 µg/L, respectively; p < 0.001). (4) Conclusions: Our findings support the hypothesis that an adverse intrauterine environment can compromise the availability of FT4 in cord blood as well as the iodine metabolism in the fetus. These differences are more noticeable in preterm and/or small fetuses.

FUNCTIONAL HETEROGENEITY OF THE THYROID AND POSSIBLE PRESENCE OF IODOTYROSINE-LIKE COMPOUNDS IN NORMAL SERUM

1965 ◽  
Vol 48 (2) ◽  
pp. 199-208 ◽  
Author(s):  
J. D. Wiener
Keyword(s):  
Human Subjects ◽  
Thyroid Tissue ◽  
Normal Serum ◽  
Schematic Model ◽  
Functional Heterogeneity ◽  
Rat Serum ◽  
Iodine Metabolism ◽  
Normal Rat ◽  
Isotope Equilibrium ◽  
Equilibrium Experiment

ABSTRACT After the administration of 131I to normal animals or human subjects, labelled thyroxine and triiodothyronine, but at most traces of labelled iodotyrosines can be detected in the serum. However, several investigators using various methods claim to have found considerable amounts of one or both of these iodotyrosines when assaying the stable (non-radioactive) iodinated compounds in the serum. Considering the available evidence as convincing for the present, an attempt has been made to explain this discrepancy. A schematic model of the thyroidal iodine metabolism is proposed, based on (a) the hypothesis that the iodotyrosines are present in the circulation in a »masked« form (i. e. protected against deiodination), and (b) the known functional heterogeneity of the thyroid tissue. This heterogeneity should be of a qualitative as well as quantitative nature. As the physical decay rate of 131I is short in comparison with the turnover rate of the masked iodotyrosine pool, an isotope equilibrium experiment with rats was carried out, using the long-lived isotope 125I. The results of this experiment, viewed together with those of a similar investigation published by others, seem to lend support to the proposed mechanism. The presence of non-negligible amounts of a diiodotyrosine-like compound in normal rat serum seems fairly well established.

THIOURACIL TREATMENT IN PREGNANCY AND LACTATION IN THE DOG

1962 ◽  
Vol 40 (3) ◽  
pp. 430-440 ◽  
Author(s):  
K. E. Arosenius ◽  
H. Derblom ◽  
G. Nylander
Keyword(s):  
Thyroid Gland ◽  
List Type ◽  
Histological Changes ◽  
Morphological Effect ◽  
Iodine Metabolism ◽  
Pregnancy And Lactation ◽  
In Pregnancy

ABSTRACT The offspring of bitches treated with thiouracil during pregnancy and lactation were studied with regard to certain aspects of iodine metabolism and also to the morphological effect on the thyroid gland, as compared with controls of the same age and weight. At the age of six months, when the dogs were virtually fully grown, the thyroid gland still exhibited the effects of the thiouracil treatment of the mothers as manifested by an increased uptake of 131I, enlargement, and histological changes of a hyperplastic type. The significance of these deviations from normal iodine metabolism and morphology is discussed with particular reference to the dangers of thiouracil medication during pregnancy.

A COMPARATIVE STUDY OF IODINE METABOLISM IN PREGNANCY, SPORADIC GOITRE AND THYROTOXICOSIS

1965 ◽  
Vol 48 (1) ◽  
pp. 14-22 ◽  
Author(s):  
S. A. Aboul-Khair ◽  
J. Crooks
Keyword(s):  
Comparative Study ◽  
Pregnant Women ◽  
Iodine Deficiency ◽  
Physiological Responses ◽  
Iodine Uptake ◽  
Thyroid Activity ◽  
Deficiency State ◽  
Iodine Metabolism ◽  
Inorganic Iodine ◽  
In Pregnancy

ABSTRACT Studies of iodine metabolism have been carried out in 15 pregnant women, 33 cases with sporadic goitre and 11 with thyrotoxicosis. A low plasma inorganic iodine was common to the three groups. In pregnancy and sporadic goitre the thyroid clearance of iodine was elevated and the absolute iodine uptake normal. A high thyroid clearance of iodine in thyrotoxicosis was associated with a high absolute iodine uptake. The results suggest that both pregnancy and sporadic goitre are physiological responses to an iodine deficiency state while the iodine deficiency state of thyrotoxicosis is secondary to increased thyroid activity.

DIE ZUSAMMENSETZUNG DER JODHALTIGEN VERBINDUNGEN UND IHRE BEZIEHUNG ZUM JODUMSATZ IN EUTHYREOTEN STRUMEN

1962 ◽  
Vol 41 (4) ◽  
pp. 584-594 ◽  
Author(s):  
Dankwart Reinwein ◽  
Erich Klein
Keyword(s):  
Column Chromatography ◽  
Iodine Content ◽  
High Plasma ◽  
Secretion Rate ◽  
Total Iodine ◽  
Iodine Compound ◽  
Hormonal Secretion ◽  
Carrier Free ◽  
Iodine Metabolism ◽  
Diffuse Goiter

ABSTRACT The iodine metabolism was investigated in 29 patients with euthyroid non-endemic diffuse goiter. 1 to 14 days before thyroidectomy the patients received carrier-free 131I. The chemical iodine fractions (PBI, BEI and iodide) of the thyroid and the labelled iodine compound were analyzed by means of paper- and column chromatography. In one gland the total iodine content varied only by ± 19.6% of the average, the relative shares of PBI, BEI and iodide as well as that of the iodoamino acids being equal. Monoiodotyrosine, diiodotyrosine and thyroxine were found in the thyroid homogenate without hydrolysis. The homogenate after hydrolysis contained more iodotyrosines at the expense of iodothyronines than do normal glands. 17 goiters with normal 131I-uptake showed a high total iodine content (14.2 ± 5.0 mg) whilst 9 goiters with an increased 131I-uptake had low values (3.58 ± 0.6 mg). The opposite was found for the relative shares of BEI with the chromatographically isolated iodothyronines thyroxine, triiodothyronine and an unidentified iodine compound. Goiters with »high plasma PB131I« were characterized by a faster transfer of 131I into the more heavily iodinated compounds than is found in glands with a normal hormonal secretion rate. The highest values for the iodothyronines were found in goiters with increased 131I-uptake together with a high hormonal secretion rate. From this study it appears that the changes in the iodine-poor glands are due to a defective exo- or endogenous iodine supply. The observed alterations in iodine-rich glands are probably induced by a faulty iodine utilization characterized by an incomplete iodotyrosyl-coupling defect.

IODINE METABOLISM IN A GROUP OF OLD AGE PEOPLE

1971 ◽  
Vol 68 (1_Supplb) ◽  
pp. S17
Author(s):  
M. H. Helsloot ◽  
P. J. der Kinderen ◽  
F. Schwarz
Keyword(s):  
Old Age ◽  
Iodine Metabolism

QUANTITATIVE STUDIES OF IODINE METABOLISM IN SPORADIC, NON-TOXIC GOITRE

1974 ◽  
Vol 76 (1) ◽  
pp. 67-73 ◽  
Author(s):  
H. Agerbæk ◽  
S. E. Jensen
Keyword(s):  
Iodine Deficiency ◽  
Iodine Uptake ◽  
Quantitative Studies ◽  
Euthyroid State ◽  
Iodine Metabolism ◽  
Dynamic Patterns ◽  
Perchlorate Discharge Test ◽  
Normal Controls ◽  
Discharge Test

ABSTRACT In 129 patients with non-toxic goitre and 27 normal controls, thyroid dynamic patterns were estimated in an attempt to elucidate pathogenesis. The clinically euthyroid state was confirmed by measurement of PBI, T3-sephadex uptake and BMR. Thyroid clearance (th. cl.), plasma iodide (PII), and absolute iodine uptake (AIU) were determined and a perchlorate discharge test performed. Twenty patients (16%) had a high AIU and were thus suspected of having dyshormonogenesis; nine were thoroughly investigated and in six dyshormonogenesis was found. Both normals and non-toxic goitre patients had a low PII, but in the goitrous patients values were lowest. The thyroid clearance of iodide was significantly higher in the goitre patients, suggesting iodine deficiency to be a major aetiologic factor for goitre formation. AIU was higher in the goitre patients than in normals, suggesting a larger iodine leakage from the thyroid in these patients.

SUBACUTE THYROIDITIS

1960 ◽  
Vol XXXIII (III) ◽  
pp. 457-472 ◽  
Author(s):  
B.-A. Lamberg ◽  
G. Hintze ◽  
R. Jussila ◽  
M. Berlin
Keyword(s):  
Thyroid Function ◽  
Early Phase ◽  
Radioactive Iodine ◽  
Serum Proteins ◽  
Conversion Ratio ◽  
Subacute Thyroiditis ◽  
Synthetic Analogues ◽  
The Third ◽  
Thyroid Uptake ◽  
Iodine Metabolism

ABSTRACT A series of cases of clinically diagnosed subacute thyroiditis comprising 11 patients is reported. Studies on the iodine metabolism, electrophoretic distribution of the serum proteins and the responsiveness to TSH were carried out. The patients were observed for periods up to 16 months from the onset of the disease. In the early phase there was an elevation of the serum PBI in a few cases and hyperthyroid signs in some, accompanied by depressed thyroid uptake of radioactive iodine and a fairly good response to TSH. Later, the thyroid grew hard and the iodine metabolism changed. In several cases there was a marked increase in the conversion ratio and the serum PB131I level. The responses to TSH was variable for different parameters of thyroid function, suggesting a state of »low thyroid reserve« as defined by Jefferies et al. (1956). Hypothyroidism developed in 3 cases; in two of them there was a response to exogenous TSH, in the third no response was seen at this stage of the disease. Cortisone and synthetic analogues seem to be of great benefit in the treatment of the acute symptoms of the disease.

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