Related Experiment Video
Updated: Jun 4, 2026
04:39
Generation of a Mouse Spontaneous Autoimmune Thyroiditis Model
Published on: March 17, 2023
Correlation between iodine intake and thyroid function in subjects with normal thyroid function.
Sena Hwang1, Eun Young Lee, Woo Kyung Lee
1Endocrinology, Severance Hospital Integrative Research Institute for Cerebral and Cardiovascular Diseases, Department of Internal Medicine, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, 120-752, South Korea.
Biological Trace Element Research
|February 23, 2011
Summary
High iodine intake may negatively impact thyroid function even in healthy individuals. This study found correlations between iodine levels and thyroid hormones, suggesting potential risks of excessive intake.
Area of Science:
- Endocrinology
- Thyroid Research
- Public Health Nutrition
Background:
- Excessive iodine intake is a known cause of hypothyroidism in individuals with pre-existing thyroid disorders.
- Limited research exists on the effects of high iodine intake on individuals with normal thyroid function and no history of autoimmune thyroid disease.
Purpose of the Study:
- To investigate the hypothesis that high iodine intake can subtly alter thyroid function in subjects with normal thyroid function.
- To explore the relationship between urinary iodine excretion, thyroid hormone levels, and thyroid antibodies in a healthy population.
Main Methods:
- Analysis of 337 subjects (64 men, 273 women; mean age 49 years) with normal thyroid peroxidase antibodies (TPO-Ab) and thyroglobulin antibodies (Tg-Ab).
- Measurement of urinary iodine excretion, free thyroxine (FT4), and thyroid-stimulating hormone (TSH).
- Statistical correlation analysis between iodine levels, thyroid hormones, and antibody levels.
Main Results:
- Urinary iodine excretion showed a negative correlation with FT4 (γ = -0.11, p = 0.043) and a positive trend with TSH (γ = 0.10, p = 0.068).
- Thyroid peroxidase antibodies (TPO-Ab), even within the normal reference range, were negatively correlated with FT4 (γ = -0.17, p = 0.002) and positively correlated with TSH (γ = 0.13, p = 0.021).
- 61.7% of subjects had circulating TPO-Ab within the normal reference range, indicating a subclinical presence of antibodies.
Conclusions:
- High iodine intake may adversely affect thyroid hormone levels, specifically FT4 and TSH, even in individuals with normal baseline thyroid function.
- The presence of TPO-Ab, even at normal levels, may indicate a heightened susceptibility to the effects of iodine on thyroid function.
- Further population-based studies are warranted to clarify the long-term implications of high iodine intake on thyroid health in the general population.
Related Concept Videos
01:20Synthesis and Regulation of Thyroid Hormones
Low blood levels of the thyroid hormones — triiodothyronine (T3) and thyroxine (T4) — signal the hypothalamus to release the thyrotropin-releasing hormone (TRH). TRH then reaches the pituitary gland and stimulates the release of thyroid-stimulating hormone(TSH) into the bloodstream.
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
01:18Functions of Thyroid Hormones
The thyroid hormone (TH) plays a pivotal role in the intricate orchestration of physiological processes, exerting profound effects on development, metabolism, and homeostasis throughout different life stages.
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
01:23Redox Titration: Iodimetry and Iodometry
Iodometry and iodimetry are analytical methods used to determine the concentration of oxidizing or reducing agents using iodine. In iodometric titrations, the oxidizing analyte solution is usually acidified and treated with an excess of iodide ions, which generates an equivalent amount of iodine in equilibrium with triiodide. The released iodine is subsequently titrated directly against a standardized reducing agent. As the dilute iodine color becomes pale yellow, a few drops of freshly...
01:23Hypothyroidism II: Pathophysiology
Hypothyroidism is a disorder characterized by insufficient production of thyroid hormones, which regulate metabolism, energy balance, and multiple organ systems.TypesHypothyroidism is classified based on the level of dysfunction. Primary hypothyroidism results from intrinsic thyroid gland dysfunction, causing reduced hormone production despite normal or increased stimulation. Secondary hypothyroidism arises from inadequate thyroid-stimulating hormone (TSH) secretion by the pituitary. Tertiary...
01:27Goiter
Goiter refers to an abnormal enlargement of the thyroid gland that may appear as a diffuse goiter (uniform enlargement) or nodular (single or multiple nodules). Functionally, it is classified as nontoxic (normal/low hormone levels) or toxic (excess hormone production).PathophysiologyDiffuse thyroid enlargement typically results from prolonged stimulation by thyroid-stimulating hormone (TSH) or TSH-like agents, commonly seen in hypothyroidism or iodine deficiency. In contrast, in hyperthyroid...
01:27Hyperthyroidism II: Pathophysiology
Hyperthyroidism is a hypermetabolic state caused by elevated levels of thyroid hormones, triiodothyronine (T3) and thyroxine (T4). It results from dysregulation at the thyroid, pituitary, or immune system level and affects multiple organ systems.PathophysiologyThe most common cause of hyperthyroidism is Graves’ disease, an autoimmune disorder in which antibodies, specifically thyroid-stimulating antibodies (TSAb), a subtype of TSH receptor antibodies (TRAb), bind to and activate TSH receptors...