Journal: Investigative Radiology
Authors: Susan S Jick, Monique Hedderson, Fei Xu, Yingkai Cheng, Petra Palkowitsch, Alexander Michel
NLM Citation: Jick SS, Hedderson M, Xu F, Cheng Y, Palkowitsch P, Michel A. Iodinated contrast agents and risk of hypothyroidism in young children in the United States. Invest Radiol. 2019 May;54(5):296-301. doi: 10.1097/RLI.0000000000000541. PMID: 30562272.
Abstract
Background: Although it is generally acknowledged that exposure to iodine contrast agents can interfere with thyroid function, little is known about the incidence of iodine-induced hypothyroidism in young children (younger than the age of 4 years).
Study objectives: This was a retrospective cohort study to estimate the incidence rate of detected hypothyroidism in a US-based general population of pediatric patients exposed to an iodinated contrast agent.
Setting: The study was conducted in Kaiser Permanente Northern California, an integrated health care delivery system.
Study population: This study included 2320 pediatric patients younger than 4 years of age who had a diagnostic procedure with an iodinated contrast agent during years 2008 to 2016.
Results: Among 2320 young children who met our study criteria, we identified 34 who met the initial criteria to be a case of hypothyroidism. The incidence density ratio for all hypothyroidism in iodine contrast agent-exposed patients was 1.33 per 1000 person months (95% confidence interval, 0.9-1.8). Most cases appeared to have subclinical hypothyroidism. The rate was higher for the probably iodine-induced cases (0.90 per 1000 person months) compared with cases with a possible alternate etiology (0.43 per 1000 person months), for males compared with females, and among children who had a heart catheterization compared with those with a computed tomography scan. It was also highest among the youngest children (younger than 3 months old), and decreased with increasing age.
Discussion: Our finding of hypothyroidism in young children exposed to iodine contrast agents (1.33 per 1000 person months [95% confidence interval, 0.9-1.8]) is broadly consistent with the sparse literature on this outcome.
