Reduced radioiodine uptake at increased iodine intake and 131I-induced release of “cold” iodine stored in the thyroid

2005 ◽  
Vol 44 (04) ◽  
pp. 137-142 ◽  
Author(s):  
A. Haase ◽  
M. Seyfarth ◽  
B. E. Wenzel ◽  
E. Richter ◽  
M. Baehre ◽  
...  
Keyword(s):  
Radioiodine Therapy ◽  
Urinary Iodine ◽  
Thyroid Volume ◽  
Target Volume ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Target Dose ◽  
Radioiodine Uptake ◽  
Iodine Excretion ◽  
Iodine Release

Summary Aim: The extent of urinary iodine excretion (UIE) provides information about iodine supply and release. In the present study we investigated correlations between UIE and radioiodine uptake (RIU) as well as effects of radioiodine therapy on UIE in patients with autonomous goitre. Patients, methods: In 197 consecutive patients with thyroid autonomy, UIE was measured twice during radioiodine test (RITe) and correlated with RIU. In 98 of these patients, thyroglobulin and thyroid volume (V) were determined prior to therapy. Individual changes in urinary iodine excretion (ΔUIE) and TG (ΔTG) could be investigated four weeks (4W) and six months (6M) after radioiodine therapy. Additionally, ΔV was determined 6M after therapy. ΔUIE, ΔTG and ΔV were correlated with target dose and target volume. Results: Patients with higher iodine excretion exhibited significantly lower thyroidal radioiodine uptake values. Twofold increased UIE prior to therapy decreased radioiodine uptake by 25%. Compared with pretherapeutic values, UIE and TG were significantly increased four weeks after radioiodine therapy (p <0.001). Median values of both parameters were found to be doubled. The product of target dose and target volume was not only correlated with a decrease of thyroid volume 6M after therapy, but also with an increase of UIE and TG in the early phase after therapy. Conclusions: It was confirmed that UIE during RITe is a measure for iodine intake and can be used to investigate the competition between stable iodine and radioiodine. The increase of UIE and TG four weeks after therapeutic administration of radioiodine can be explained by disintegrated thyroid follicles. The therapy-induced iodine release may be one important cause for the development of hyperthyroidism in some patients during the first weeks after radioiodine therapy. It may contribute to the known decrease of radioiodine uptake after preapplications of 131I in various thyroid diseases.

Influence of Radioiodine Therapy on Urinary Iodine Excretion

1998 ◽  
Vol 37 (03) ◽  
pp. 107-112 ◽  
Author(s):  
I. Lauer ◽  
M. Bähre ◽  
E. Richter ◽  
B. Melier
Keyword(s):  
Time Course ◽  
Radioiodine Therapy ◽  
Urinary Iodine ◽  
Target Volume ◽  
Urinary Iodine Excretion ◽  
Urinary Creatinine ◽  
Iodine Excretion ◽  
Kinetics Of ◽  
Persistent Elevation ◽  
Benign Thyroid

Summary Aim: In 214 patients with benign thyroid diseases the time-course of urinary iodine excretion (UIE) was investigated in order to identify changes after radioiodine therapy (RITh). Method: UIE was measured photometrically (cerium-arsenite method) and related to urinary creatinine on the first and last day of the radioiodine test and then three days, seven days, four weeks, and six months after 1311 administration. Results: As compared with the level found immediately before radioiodine therapy, median UIE had almost doubled four weeks after therapy and was still significantly elevated six months after therapy. This increase correlated significantly with the target volume as measured by scintigraphy and sonography. Conclusions: The persistent elevation of UIE for months after RITh is a measure of treatment-induced damage to thyrocytes. Therefore, in view of the unfavourable kinetics of iodine that follow it, RITh should if possible be given via a single-dose regime.

scholarly journals Nutritional iodine status and obesity

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Mariacarla Moleti ◽  
Maria Di Mauro ◽  
Giuseppe Paola ◽  
Antonella Olivieri ◽  
Francesco Vermiglio
Keyword(s):  
Bariatric Surgery ◽  
Body Mass Index ◽  
Thyroid Hormones ◽  
Urinary Iodine ◽  
Thyroid Volume ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Obese Children ◽  
Iodine Status ◽  
Iodine Excretion

AbstractIodine is an essential component of the thyroid hormones, thyroxine and triiodothyronine. Its availability strictly depends on iodine content of foods, which may vary from very low to very high. Inadequate iodine intake (deficiency or excess) may affect thyroid function resulting in hypothyroidism or hyperthyroidism. Based on median urinary iodine concentrations, epidemiological criteria have been established for the categorization and monitoring of nutritional iodine status of a population (or subgroups of populations). Additional methods for iodine intake assessment include measurement of thyroid size (by thyroid palpation or ultrasonography) and of biochemical parameters, such as neonatal thyroid stimulating hormone, thyroglobulin and thyroid hormones.Recent studies carried out in overweight/obese children and adults provide evidence that body mass index (BMI) may significantly influence the above indicators, thus theoretically affecting the epidemiological evaluation of nutritional iodine status in populations.In this short review, we analyze current knowledge on the effects of overweight and obesity on indicators of adequacy and monitoring of iodine status, namely urinary iodine excretion and thyroid volume and echogenicity.Data on urinary iodine excretion in overweight/obese children are divergent, as both increased and reduced levels have been reported in overweight/obese children compared to normal-weight controls.Whether gastrointestinal surgery may affect iodine absorption and lead to iodine deficiency in patients undergoing bariatric surgery has been evaluated in a limited number of studies, which excluded iodine deficiency, thus suggesting that supplements usually recommended after bariatric surgery do not need to include iodine.Albeit limited, evidence on thyroid volume and obesity is consistent with a direct relationship between thyroid volume and BMI, irrespective of nutritional iodine status. Finally, a higher frequency of thyroid hypoechoic pattern has been described in overweight/obese children. This finding has been recently related to an increased adipocyte infiltration and thyroid parenchyma imbibition mediated by inflammatory cytokines and should be considered when the frequency of thyroid hypoechoic pattern is used as non-invasive marker to indirectly assess thyroid autoimmunity in monitoring Universal Salt Iodization programs. Further studies, specifically addressing the role of schoolchildren body mass index as a factor potentially influencing iodine intake indicators are needed.

scholarly journals Iodine nutrition in pregnancy and lactation in Iran

2007 ◽  
Vol 10 (12A) ◽  
pp. 1596-1599 ◽  
Author(s):  
Fereidoun Azizi
Keyword(s):  
Pregnant Women ◽  
Urinary Iodine ◽  
Thyroid Volume ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Lactating Women ◽  
Iodine Excretion ◽  
Pregnancy And Lactation

AbstractObjective: To describe studies evaluating urinary iodine excretion during pregnancy and lactation in women living in cities with adequate or more than adequate iodine intake.Design: Cross-sectional study conducted between 1996 and 1998 in pregnant women and a study of lactating women conducted in 2003.Settings and Subjects: Pregnant women attending prenatal clinics in four cities in the Islamic Republic of Iran. Urinary iodine excretion and thyroid volume was measured in 403 women. In a second study, 100 lactating women from Taleghani Hospital in Gorgan, Iran were evaluated for thyroid size, and both urinary and breast milk iodine concentrations were determined.Results: In Rasht city, 84% of pregnant women had a urinary iodine concentration of ≥ 200 μg l-1, while in the other cities this percentage ranged from 45 to 55%. When data were combined for the cities of Ilam, Isfahan and Tehran, where women have an adequate or more than adequate median urinary iodine concentration, 51% of pregnant women had a urinary iodine concentration less than that recommended during pregnancy. In Rasht, where the median urinary iodine concentration indicates an excessive iodine intake, 15.4% of pregnant women had a urinary iodine concentration < 200 μg l-1. The mean urinary iodine concentration in lactating women was 250 μg l-1, and 16% of women had a urinary iodine concentration < 100 μg l-1. Grade 1 goitre was present in 8% of lactating women, and another 8% had grade 2 goitre.Conclusions: Findings of this study call for further attention to iodine intake during pregnancy and lactation. The currently recommended intake of iodine through universal salt iodisation may not be adequate for pregnant and lactating women, and supplementation during pregnancy and lactation should be further considered in light of the latest recommendations.

scholarly journals Urinary iodine excretion in pregnant women residing in areas with adequate iodine intake

2003 ◽  
Vol 6 (1) ◽  
pp. 95-98 ◽  
Author(s):  
F Azizi ◽  
A Aminorroya ◽  
M Hedayati ◽  
H Rezvanian ◽  
M Amini ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Urinary Iodine ◽  
Thyroid Volume ◽  
Cross Sectional Study ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Third Trimester ◽  
Cross Sectional ◽  
Iodine Excretion ◽  
Islamic Republic Of Iran

AbstractObjective:Pregnancy is accompanied by profound alterations in thyroid economy and relative iodine deficiency. The aim of this study was to evaluate urinary iodine excretion of pregnant women in cities with adequate and more than adequate iodine intake.Methods:A cross-sectional study was performed on schoolchildren and pregnant women in four cities in the Islamic Republic of Iran. Urinary iodine excretion was measured for 438 schoolchildren and 403 pregnant women. In addition, in Isfahan City, thyroid volume was measured by sonography for 30 pregnant women in each trimester of pregnancy and for 90 non-pregnant women who also had urinary iodine measurement.Results:Median urinary iodine of schoolchildren was 31.2, 25.0, 20.2 and 19.3 μg/dl in Rasht, Isfahan, Ilam and Tehran, respectively. Corresponding values for pregnant women were 33.8, 21.2, 19.0 and 18.6μg/dl. The percentage of pregnant women with urinary iodine below 20μg/dl was 16, 45, 55 and 54, and below 10μg/dl was 1, 7, 7 and 13, in Rasht, Isfahan, Ilam and Tehran, respectively. In Isfahan, urinary iodine was significantly decreased in the third trimester of pregnancy, compared with controls. Mean thyroid volume was 7.8±3.1 ml and 7.8±2.8 ml in pregnant and non-pregnant women, respectively.Conclusion:Recommended values for dietary iodine through universal salt iodisation may not be adequate for pregnant women, and the specific problem of iodine and pregnancy should be considered further in the light of the latest recommendations.

Iodized salt prophylaxis of endemic goiter: an experience in Toscana (Italy)

1993 ◽  
Vol 129 (6) ◽  
pp. 497-500 ◽  
Author(s):  
F Aghini-Lombardi ◽  
A Pinchera ◽  
L Antonangeli ◽  
T Rago ◽  
GF Fenzi ◽  
...  
Keyword(s):  
Iodine Deficiency ◽  
Endemic Goiter ◽  
Urinary Iodine ◽  
Thyroid Volume ◽  
Iodized Salt ◽  
Urinary Iodine Excretion ◽  
Goiter Prevalence ◽  
Iodine Excretion ◽  
Health Organization ◽  
Legislative Measures

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.

scholarly journals Nationwide Representative Survey of Dietary Iodine Intake and Urinary Excretion in Postpartum Korean Women

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3955
Author(s):  
Do-Kyung Lee ◽  
Hunjoo Lee ◽  
Hyeyoung Lee ◽  
Taehyung Yoon ◽  
Seon-Joo Park ◽  
...  
Keyword(s):  
Large Scale ◽  
Urinary Iodine ◽  
Brown Seaweed ◽  
Nationwide Survey ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Korean Women ◽  
Spot Urine ◽  
Before And After ◽  
Iodine Excretion

Iodine is an essential component of thyroid hormones, but excessive iodine intake can lead to thyroid dysfunction. Traditionally, Korean mothers consume brown seaweed soup (miyeokguk), a high source of iodine, after childbirth. There is controversy regarding the effects of excessive postpartum iodine intake on the health of mothers and infants. Thus far, there have been no nationwide large-scale surveys regarding the status of iodine intake among postpartum women in Korea. Therefore, we conducted a nationwide survey of postpartum dietary iodine intake among Korean women. In total, 1054 Korean women aged ≥19 years, at less than 8 weeks postpartum, participated in this survey. Dietary data were collected using self-reported 2-day dietary records, along with before-and-after meal photos. To evaluate the correlation between dietary iodine and urinary iodine excretion (UIE), spot urine, and 24 h urine samples were collected from 98 and 29 participants, respectively. The mean daily iodine intake among all participants was 2945.6 μg, and it gradually decreased over time after childbirth. Dietary iodine intake was significantly correlated with 24 h UIE (r = 0.396, p < 0.05) and spot urine UIE (r = 0.312, p < 0.05). Follow-up studies are required to examine the influence of excessive postpartum iodine intake on thyroid health in mothers and their infants.

Iodine and Goiter in Children

PEDIATRICS ◽  
1975 ◽  
Vol 56 (1) ◽  
pp. 82-90
Author(s):  
Frederick L. Trowbridge ◽  
Josip Matovinovic ◽  
Gordon D. McLaren ◽  
Milton Z. Nichaman
Keyword(s):  
United States ◽  
Urinary Iodine ◽  
The United States ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
High Iodine ◽  
Goiter Prevalence ◽  
Iodine Excretion ◽  
American Children

Goiter examination was performed on 7,785 children aged 9 to 16 years in four areas of the United States—Michigan, Kentucky, Texas, and Georgia. Urinary iodine and creatinine, thyroxine, protein-bound iodine, and plasma inorganic iodide determinations were made on 377 matched pairs of goitrous and nongoitrous control children. The overall prevalence of goiter was 6.8%. Most children with goiter had palpably but not visibly enlarged thyroids and showed no evidence of clinical or biochemical thyroid abnormality. Mean urinary iodine excretion was 452µg/gm of creatinine, many times the 50µg/gm of creatinine level used to define deficiency. Children with goiter and areas with high goiter prevalence tended to have higher rather than lower iodine excretion. These findings are consistent with other data indicating high iodine intakes in the United States and suggest that goiter in American children cannot be assumed to be related to iodine deficiency. The possible role of high iodine intake in the causation of goiter is discussed.

scholarly journals Chronic iodine excess does not increase the incidence of hyperthyroidism: a prospective community-based epidemiological survey in China

2007 ◽  
Vol 156 (4) ◽  
pp. 403-408 ◽  
Author(s):  
Fan Yang ◽  
Zhongyan Shan ◽  
Xiaochun Teng ◽  
Yushu Li ◽  
Haixia Guan ◽  
...  
Keyword(s):  
Urinary Iodine ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Thyroid Peroxidase ◽  
Community Based ◽  
Iodine Excess ◽  
Iodine Supplementation ◽  
Excessive Iodine ◽  
Iodine Excretion ◽  
Excessive Iodine Intake

Objective: An increasing incidence of hyperthyroidism has been observed when iodine supplementation has been introduced to an iodine-deficient population. Moreover, the influence of chronic more than adequate or excessive iodine intake on the epidemiological features of hyperthyroidism has not been widely and thoroughly described. To investigate the influences of different iodine intake levels on the incidence of hyperthyroidism, we conducted a prospective community-based survey in three communities with mild-deficient, more than adequate (previously mild deficient iodine intake), and excessive iodine intake. Subjects and methods: In three rural Chinese communities, a total of 3761 unselected inhabitants aged above 13 years participated in the original investigation and 3018 of them received identical examinations after 5 years. Thyroid function, levels of thyroid peroxidase antibody (TPOAb), thyroglobulin antibody and urinary iodine excretion were measured and thyroid ultrasound examination was also performed. Results: In three communities, median urinary iodine excretion was 88, 214, and 634 μg/l (P<0.05) respectively. The cumulative incidence of hyperthyroidism was 1.4, 0.9, and 0.8% (P>0.05) respectively. Autoimmune hyperthyroidism was predominant in thyroid hyperfunction in all the three cohorts. Either positive TPOAb (>50 U/ml) or goiter in original healthy participants was associated with the occurrence of unsuspected hyperthyroidism in 5 years (logistic regression, OR=4.2 (95% CI 1.7–8.8) for positive TPOAb, OR=3.1 (95% CI 1.4–6.8) for goiter). Conclusion: Iodine supplementation may not induce an increase in hyperthyroidism in a previously mildly iodine-deficient population. Chronic iodine excess does not apparently increase the risk of autoimmune hyperthyroidism, suggesting that excessive iodine intake may not be an environmental factor involved in the occurrence of autoimmune hyperthyroidism.

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