In the Journals

Iodinated contrast media exposure increases thyroid dysfunction risk

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July 14, 2015

A higher risk for thyroid dysfunction was found among patients exposed to iodinated contrast media, according to recent study findings published in The Journal of Clinical Endocrinology & Metabolism.

“This is the first population-based study to evaluate the risk of thyroid dysfunction in normal thyroid patients with and without [iodinated contrast media] exposure in an Asian country,” the researchers wrote.

Chien-Ning Huang, MD, PhD, of Chung San Medical University Hospital in Taiwan, and colleagues evaluated data from the Longitudinal Health Insurance Database 2005 from the Taiwan National Health Insurance program on 19,642 adults with normal thyroid exposed to iodinated contrast media (ICM; mean age, 53.9 years) and 78,568 matched controls with normal thyroid without ICM exposure (mean age, 53.6 years). Researchers sought to determine the effect of ICM exposure on the risk for thyroid dysfunction, including hyperthyroidism or hypothyroidism. Mean follow-up was 4.1 years for the ICM exposure group and 5.6 years for controls.

After adjustment, a significantly higher risk for thyroid dysfunction was found among the ICM exposure group compared with controls (HR = 1.46; 95% CI, 1.29-1.66). Compared with controls, the adjusted HR for hyperthyroidism was 1.22 (95% CI, 1.04-1.44) and the HR was 2 (95% CI, 1.65-2.44) for hypothyroidism using a subgroup analysis of patients with thyroid dysfunction.

The use of amiodarone, beta-blocker, carbamazepine, dexamethasone, interferon, interleukin-6, lithium, phenobarbital, phenytoin, propylthiouracil and rifampicin was associated with an increased risk for thyroid dysfunction (HR = 1.45; 95% CI, 1.28-1.63), hyperthyroidism (HR = 1.47; 95% CI, 1.26-1.7) and hypothyroidism (HR = 1.44; 95% CI, 1.19-1.74).

“These findings suggest that normal thyroid patients with ICM exposure had increased risk of thyroid dysfunction compared [with] that of patients with non-ICM exposure,” the researchers wrote. “The mean duration of thyroid dysfunction was 2 years after ICM exposure. Patients with a higher Charlson’s comorbidity index, Sjögren’s syndrome or [systemic lupus erythematosus] had a higher risk of thyroid dysfunction.” – by Amber Cox

Disclosure: The researchers report no relevant financial disclosures.