Decreased Radioiodine Uptake Values without Increase in Urinary Iodine Excretion

Summary:Poland, a country with mild/moderate iodine deficiency introduced an obligatory iodination salt system in 1996. Aim: To compare the results of radioiodine (131I) uptake after 5 h and 24 h with the activity of radioiodine used in the treatment of hyperthyroid patients with Graves’ disease in the years 1995 and 2003. Patients, methods: The marker of iodine content in the diet was urinary iodine excretion. 1000 randomly chosen patients (average age: 46 ± 12 years) were included in the study. Every patient had routinely estimated radioiodine uptake after 5 h and 24 h and the activity of 131I was calculated using scintigraphy and ultrasonography of the thyroid gland. Urinary iodine excretion in samples from year 1995 and 2003 was also determined in some patients and healthy volunteers. Results: The iodine load in the diet increased from 66 μg (average) in the year 1995 to 115 μg in the year 2003. Thyroid radioiodine uptake was 40% lower in comparison with the results from 1995. The average activity of 131I given in the year 2003 (10 mCi) was about 40% higher than in the year 1995 (7 mCi). Conclusion: There was significant negative correlation between higher iodine content in the diet and lower values of radioiodine uptake, which led to the application of the higher activity of 131I during treatment.

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

Nuklearmedizin ◽

10.1055/s-0038-1625756 ◽

2005 ◽

Vol 44 (04) ◽

pp. 137-142 ◽

Cited By ~ 8

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.

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Rezidivrisiko nach thyreostatischer Behandlung immunogener und nicht-immunogener Hyperthyreosen

Nuklearmedizin ◽

10.1055/s-0038-1629504 ◽

1990 ◽

Vol 29 (01) ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

E. Voth ◽

N. Dickmann ◽

H. Schicha ◽

D. Emrich

Keyword(s):

Relapse Rate ◽

Urinary Iodine ◽

Young Patients ◽

Antithyroid Drugs ◽

Urinary Iodine Excretion ◽

Old Patients ◽

Primary Disease ◽

Iodine Excretion ◽

Immunogenic Hyperthyroidism

Data of 196 patients treated for hyperthyroidism exclusively with antithyroid drugs were analyzed retrospectively concerning the relapse rate within a follow-up period of four years. Patients were subdivided for primary or recurrent disease, and for immunogenic or non-immunogenic hyperthyroidism, respectively. In immunogenic as well as in non-immunogeriic hyperthyroidism, the relapse rate was significantly lower for patients with primary disease (35% and 52%, respectively) compared to those with recurrent hyperthyroidism (82%, p <0.001 and 83%, p <0.001, respectively). In patients with primary disease, clinical, biochemical and scintigraphic parameters were tested with respect to their capability of predicting a relapse. For immunogenic hyperthyroidism the highest relapse rates were observed in young patients and in those with large goitres, whereas for non-immunogenic hyperthyroidism they were highest in old patients, in those with nodular goitres and in those without an increased urinary iodine excretion at the time of diagnosing hyperthyroidism.

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Influence of Radioiodine Therapy on Urinary Iodine Excretion

Nuklearmedizin ◽

10.1055/s-0038-1632337 ◽

1998 ◽

Vol 37 (03) ◽

pp. 107-112 ◽

Cited By ~ 1

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.

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Nativer 99mTc-Uptake in der Differentialdiagnostik von unauffälliger Schilddrüse, Struma mit Euthyreose und Schilddrüsenautonomie in einem Jodmangelgebiet

Nuklearmedizin ◽

10.1055/s-0038-1629519 ◽

1990 ◽

Vol 29 (03) ◽

pp. 113-119

Author(s):

C. R. Pickardt ◽

K. Horn ◽

G. Bechtner ◽

C. Vaitl ◽

C. M. Kirsch ◽

...

Keyword(s):

Urinary Iodine ◽

Inverse Correlation ◽

Iodine Concentration ◽

Urinary Iodine Excretion ◽

Large Scatter ◽

Spot Urine ◽

Iodine Supply ◽

Iodine Contamination ◽

Iodine Excretion ◽

Overt Hyperthyroidism

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.

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Thirty years of a Ban on the Sale of Noniodized Salt: Impact on Iodine Nutrition in Children in Himachal Pradesh, India

Food and Nutrition Bulletin ◽

10.1177/156482650502600301 ◽

2005 ◽

Vol 26 (3) ◽

pp. 255-258 ◽

Cited By ~ 7

Author(s):

Umesh Kapil ◽

Thakur Dutt Sharma ◽

Preeti Singh ◽

Sada Nand Dwivedi ◽

Supreet Kaur

Keyword(s):

Positive Impact ◽

Urinary Iodine ◽

Iodine Content ◽

Himachal Pradesh ◽

The State ◽

Urinary Iodine Excretion ◽

Successful Implementation ◽

Iodine Nutrition ◽

Salt Iodization ◽

Iodine Excretion

Background A survey conducted by the central iodine-deficiency disorders team in Himachal Pradesh, a state in the goiter-endemic belt of India, revealed that 10 of its 12 districts have an endemic prevalence of goiter. The survey was conducted to provide health program managers data to determine whether it would be necessary to initiate intervention measures. Objective To assess the status of urinary iodine excretion and household salt iodization levels after three decades of a complete ban on the sale of noniodized salt in this goiter-endemic state in India as measured by assessment of urinary iodine excretion levels and iodine content of salt at the household level. Methods The guidelines recommended by WHO/UNICEF/ICCIDD for a rapid assessment of salt iodization were adopted. In each of the 12 studied districts, all senior secondary schools were enlisted and one school was selected by using a random sampling procedure. Two hundred fifty children 11 to 18 years of age were included in the study. Urine samples were collected from a minimum of 170 children and analyzed using the wet digestion method. Salt samples were also collected from a minimum of 170 children and analyzed using the spot testing kit. Results All districts had a median urinary iodine excretion level > 200 μg/L and 82% of the families were consuming salt with an iodine content of 15 ppm or higher. Conclusions The results of the present study highlight the successful implementation of the salt iodization program in the state of Himachal Pradesh. This positive impact may be due to the comprehensive strategy adopted by the state government to improve the quality of salt, development of an effective monitoring information system and effective information, education, and communication activities.

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Evolution of urinary iodine excretion over eleven years in an adult population

Clinical Nutrition ◽

10.1016/j.clnu.2014.08.003 ◽

2015 ◽

Vol 34 (4) ◽

pp. 712-718 ◽

Cited By ~ 7

Author(s):

Carolina Gutiérrez-Repiso ◽

Natalia Colomo ◽

Gemma Rojo-Martinez ◽

Sergio Valdés ◽

Maria J. Tapia ◽

...

Keyword(s):

Adult Population ◽

Urinary Iodine ◽

Urinary Iodine Excretion ◽

Iodine Excretion

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

Acta Endocrinologica ◽

10.1530/acta.0.1290497 ◽

1993 ◽

Vol 129 (6) ◽

pp. 497-500 ◽

Cited By ~ 16

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.

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