Comparison of Knowledge and Behavior of High-Iodine Food Consumption Among Patients With Graves’ Disease and Healthy Adults in Iodine-Sufficient Area

Abstract

Background: Iodine is a required dietary supplement to solve iodine deficiencies; however, many food products may now have an excessive amount of iodine. This excess may be causing unexpected iodine-induced Graves’ disease.
 Objective: To investigate the impact of high-iodine diets on adults diagnosed with Graves’ disease and healthy adults.
 Methods: A case-control study was performed among 200 patients with Graves’ disease and 200 healthy participants in Chon Buri, Thailand, using cluster random sampling from November 2019 to March 2020. Data on iodine-rich food consumption were collected using a questionnaire. Data were analyzed using a chi-square test and multiple logistic regression.
 Results: Patients with Graves’ disease significantly less knew of high-iodine food than the control group (P < .05), particularly in eggs, processed foods, ready-to-eat food, cod liver oil, and high-iodine vegetables. A frequent consumption of high-iodine food items, including fermented food (OR, 2.20; 95% CI, 1.20 - 4.02), ready-to-eat food (OR, 2.08; 95% CI, 1.02 - 4.22), high-iodine vegetables (OR, 1.72; 95% CI, 1.13 - 2.61), bakery (OR, 1.99; 95% CI, 1.10 - 3.64), iodine-supplemented sauces (OR, 1.79; 95% CI, 1.18 - 2.72), and iodized salts (OR, 1.62; 95% CI, 1.02 - 2.56) was higher in Graves’ disease patients.
 Conclusions: In iodine sufficiency area, patients with Graves’ disease less knew and more frequently consumed high-iodine foods than healthy participants.