Clinical trial NCT04304794: Iodinated Contrast Media Induced Hyperthyroidism
Official title: Prevention of Iodinated Contrast Media Induced Hyperthyroidism in Patients With Euthyroid Goiter
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Hyperthyroidism/Thyrotoxicosis
Hyperthyroidism; Goiter
Iodine Induced Thyrotoxicosis
Contrast Media Adverse Reaction
Thyrotoxicosis of Other Specified Origin
Keywords: Hyperthyroidism
Iodinated contrast media
Euthyroid goiter
Thyroid nodules
Thyroid volume
Thiamazole
Sodium perchlorate
Lead sponsor: Medical University of Warsaw
Sponsor class: OTHER
Collaborators: name: National Institute of Cardiology, Warsaw, Poland
First posted: 2020-03-11
Enrollment: 36
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: 36 patients (15 males) with euthyroid goiter and cardiovascular comorbidities admitted to the Institute of Cardiology between January 2015 and November 2019. The median age of treated patients was 68 years old.

Brief summary: The proper synthesis of thyroid hormones is dependent on adequate iodine supply. The mean daily iodine intake recommended by World Health Organization is 150 mg. Iodinated contrast medium (ICM) typically contains 13 500 mg of free iodine and 15-60 g of bound iodine, an amount well above acceptable upper level. In a situation of excess iodine, thyroid discontinues the release of hormones (Wolff-Chaikoff effect), which is usually transient, although can persist causing hypothyroidism. Iodine-induced hyperthyroidism (IIH), known as the Jod-Basedow phenomenon is infrequent, but elderly patients and individuals with autonomously functioning nodular goiters are at higher risk of developing this dysfunction. According to recent studies the risk of ICM-induced hyperthyroidism appears to be low. The prevalence has not been well assessed and varies from 1 % to 10 %. Currently, there are no specific guidelines concerning the prophylactic therapy of IIH. American Thyroid Association (ATA) does not recommend routine administration of antithyroid drugs before iodinated contrast medium for all patients, however, advises to consider prophylaxis in patients at high risk of developing IIH or with cardiovascular comorbidities. ATA recommends avoidance of additional iodine and administration of b-blockers alone or with antithyroid drugs as a treatment of IIH, depending on the severity of hyperthyroidism.

This study was performed to evaluate the influence of ICM on thyroid status and advantages of prophylactic therapy during ICM exposure in patients with euthyroid goiter and cardiovascular comorbidities. The association between the incidence of IIH and thyroid volume was also assessed.

Detailed description: Patients were divided into two subsets on the basis of received prophylactic therapy. Group with prophylaxis (13 patients) received thiamazole alone (7 patients) or with sodium perchlorate (6 patients). The prophylaxis was administered one day prior to iodinated contrast medium (ICM) and for at least 14 days after ICM for thiamazole (20-40 mg/daily) and 10 days after ICM for sodium perchlorate (900 mg/daily). Group without prophylaxis (23 patients) received no prophylactic treatment. Laboratory tests were performed before and after ICM injection in all patients from both evaluated groups. Each individual had TSH and creatinine level measured at baseline. The investigators analyzed clinical data such as age, sex, mean volume of contrast media, goiter size and patients' comorbidities. Levels of TSH, FT3 and FT4 were evaluated retrospectively at different points in time after ICM. Ultrasonography was performed in each patient to assess thyroid morphology. The investigators performed a comparison between both groups in regard to duration of overt hyperthyroidism and thiamazole treatment. Thyroid volume was compared between patients who developed hyperthyroidism after ICM injection and remained euthyroid after ICM injection. Patients diagnosed with overt hyperthyroidism were treated with thiamazole.

Eligibility criteria: Inclusion Criteria:

* euthyroidism at baseline (defined as TSH level within the reference range)
* diffuse or multinodular goiter
* iodinated contrast media (ICM) exposure
* time of observation after ICM exposure longer than 4 weeks

Exclusion Criteria:

* Graves' disease
* administration of thyroid hormones, glucocorticoids, iodine-containing medications or iodine contrast agent within the past 6 months

Primary outcomes:
measure: Influence of iodinated contrast medium administration on thyroid function.
timeFrame: up to 72 weeks
measure: Evaluation of the association between the incidence of iodine-induced hyperthyroidism and thyroid volume.
timeFrame: up to 72 weeks
measure: Evaluation of the association between the incidence of iodine-induced hyperthyroidism and the use of prophylactic treatment with antithyroid drugs before and after iodinated-contrast medium injection.
timeFrame: up to 72 weeks
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: Department of Endocrinology Medical University of Warsaw
name: Piotr Miśkiewicz, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: