Excessive Iodine Intake Does Not Increase the Recurrence Rate of Graves' Disease after Withdrawal of the Antithyroid Drug in an Iodine-Replete Area

Abstract

Background and Objectives: The relationship between iodine intake and effects of antithyroid drugs (ATD) for Graves' disease, especially in iodine-deficient areas, has been demonstrated in many studies. However, it was not clear how chronic high iodine intake influenced the effectiveness of ATD in an iodine-replete area. This study aimed to clarify the effect of iodine intake on clinical outcomes of Graves' disease after discontinuation of ATD in Korea, an iodine-replete area. Methods: A total of 142 patients with Graves' disease who visited the outpatient clinic regularly and stopped their ATD between October 2011 and April 2013 were enrolled in our study. Urinary iodine concentration (UIC) was measured just before and after the discontinuation of ATD. Results: Median UIC was not significantly different between the remission and relapse groups, as well as among the four treatment groups (group 1, remission after initial treatment; group 2, remission after repeated treatment; group 3, early relapse within a year; group 4, late relapse after a year). Remission rates did not show a significant difference between the excessive iodine intake (UIC ≥300 μg/l) and average iodine intake groups (UIC <300 μg/l). Conclusions: The present study suggests that excessive iodine intake does not have an effect on the clinical outcomes of Graves' disease in an iodine-replete area, and therefore diet control with iodine restriction might not be necessary in the management of Graves' disease.

Guidelines for the treatment of childhood-onset Graves’ disease in Japan, 2016

“…However, in areas without iodine deficiency, iodine restrictions, during the initial treatment of Graves’ disease did not improve the treatment outcomes ( 108 ). In addition, iodine intake was not found to affect recurrence ( 109 ). Therefore, in Japan, it is not necessary to restrict dietary iodine intake as a component of Graves’ disease management.…”

Can we predict relapse in Graves’ disease? Results from a systematic review and meta-analysis

“…1 according to suggestions of the PRISMA group (7)). Of these, 375 fulltext articles were assessed for eligibility and 54 trials were included in the final data analysis (9,10,11,12,13,14,15,16,17,18,19,20,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49 Tables 1 and 2). Of note, the number of patients does not add up to the grand total as data reported were both used for the genomic data table and the quantitative analysis.…”

Effect of Selenium Supplementation on Recurrent Hyperthyroidism Caused by Graves’ Disease: A Prospective Pilot Study

“…Antithyroid drugs (ATDs) inhibiting thyroid hormone syntheses are the principal treatment method for Graves' disease, but it is associated with high rate of recurrence. About 50 % patients will achieve remission after receiving ATDs therapy for about 12-18 months [4][5][6], but there is high prevalence of recurrence in those patients with remission, ranging from 30 to 70 % in published studies [7][8][9]. Some scholars recommend groups at baseline.…”