Division of Endocrinology, Department of Internal Medicine, Myongji Hospital, Hanyang University College of Medicine, Goyang 10475, South Korea.
Department of Social Epidemiology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
Endocr Rev. 2024 Nov 22;45(6):858-879. doi: 10.1210/endrev/bnae019.
Iodine is a micronutrient that is required for thyroid hormone synthesis. The iodide cycle in thyroid hormone synthesis consists of a series of transport, oxidation, organification, and binding/coupling steps in thyroid follicular cells. Common sources of iodine include the consumption of an iodine-rich diet or iodine-fortified foods, the administration of amiodarone, iodine-containing supplements, or iodinated contrast media, and other miscellaneous sources. Methods to assess population iodine status include the measurement of urinary iodine concentrations, blood thyroglobulin levels, prevalence of elevated neonatal thyrotropin levels, and thyroid volume. Although excessive iodine intake or exposure is generally well tolerated, an acute iodine load may result in thyroid dysfunction (hypothyroidism or hyperthyroidism) in certain susceptible individuals due to the failure to escape from the Wolff-Chaikoff effect and to the Jod-Basedow phenomenon, respectively. In this review, we discuss the associations between excessive iodine intake or exposure, with particular focus on iodinated contrast media as a common source of excess iodine in health care settings, and risks of incident thyroid dysfunction. We also summarize the risks of iodine excess in vulnerable populations and review current guidelines regarding the screening and monitoring of iodinated contrast-induced thyroid dysfunction. Finally, we discuss the long-term potential nonthyroidal health risks associated with iodine excess and suggest the need for more data to define safe upper limits for iodine intake, particularly in high-risk populations.
碘是一种必需的微量元素，用于甲状腺激素合成。甲状腺激素合成中的碘循环包括甲状腺滤泡细胞中的一系列运输、氧化、有机化和结合/偶联步骤。碘的常见来源包括摄入富含碘的饮食或强化碘食品、使用胺碘酮、碘补充剂或含碘造影剂，以及其他各种来源。评估人群碘状况的方法包括测量尿碘浓度、血液甲状腺球蛋白水平、新生儿促甲状腺激素水平升高的患病率以及甲状腺体积。尽管过量摄入或暴露碘通常是可以耐受的，但由于未能逃脱 Wolff-Chaikoff 效应和 Jod-Basedow 现象，急性碘负荷可能导致某些易感个体发生甲状腺功能障碍（甲状腺功能减退或甲状腺功能亢进）。在这篇综述中，我们讨论了过量碘摄入或暴露与甲状腺功能障碍风险之间的关联，特别关注碘造影剂作为医疗环境中过量碘的常见来源，以及碘造影剂导致甲状腺功能障碍的风险。我们还总结了碘过量对脆弱人群的风险，并回顾了当前关于碘造影剂诱导的甲状腺功能障碍的筛查和监测指南。最后，我们讨论了与碘过量相关的长期潜在非甲状腺健康风险，并建议需要更多数据来确定安全的碘摄入量上限，特别是在高危人群中。
