Introduction of iodized salt:

According to iodized salt, the most commonly used iodine is potassium iodate, potassium iodide and sodium iodide, and sometimes a little magnesium carbonate is added to make it more mobile. Iodine deficiency disease is an endemic disease all over the world. In 1980s, it was recognized that iodine deficiency could not only lead to endemic goiter, but also affect brain development to varying degrees, which reduced the quality of population in epidemic areas.

In China 1996, salt iodization was realized throughout the country. Since then, iodine deficiency disorders have been effectively controlled and achieved remarkable results. However, it is also found that the prevalence of hyperthyroidism and other diseases is increasing, and the composition of thyroid diseases has changed.

Effect of universal salt iodization on thyroid diseases in China;

1, goiter

Intake of a large amount of iodine can also cause goiter. As early as 1980 in China, it was found that fishermen in Bohai Bay drank deep well water with high iodine and caused goiter. Drugs containing a lot of iodine can also cause goiter, such as some contrast agents, compound iodine solution, amiodarone, kelp of traditional Chinese medicine, seaweed and so on.

The cause of goiter caused by iodine has not been clarified, which may be due to escape in the later stage, or too much iodine destroys thyroglobulin, or too much iodine continuously inhibits the activity of thyroid peroxidase. If goiter is found in non-iodine-deficient areas, excessive iodine should be considered, and patients should not be blindly supplemented with iodine. Urine iodine can be measured first in areas where conditions permit.

2. Hyperthyroidism caused by iodine

Hyperthyroidism can be divided into immune hyperthyroidism (Graves' disease, GD) and hyperthyroidism with thyroid autonomic function (single nodule, multiple nodules or diffuse Plummer's disease, PD). It is generally believed that the biological basis of IIH is the generation of functional autonomous thyroid cells due to gene mutation.

Hyperthyroidism can occur when the number of such cells is enough and the iodine supply is increased. These changes can occur in a certain part of the thyroid gland or during the formation of thyroid nodules. It is also possible that those GD patients who have no symptoms due to iodine deficiency show IIH because of increasing iodine intake.