Endocrine Health - Thyroid

Question 1

Q: What hormone does the hypothalamus release to stimulate TSH release from the anterior pituitary?

Answer 1

A: The hypothalamus releases thyrotropin-releasing hormone (TRH).

Question 2

Q: What role does TSH play in thyroid function?

Answer 2

A: TSH stimulates the thyroid to produce T4 (thyroxine) and T3 (triiodothyronine).

Question 3

Q: What is the role of iodothyronine deiodinases in the thyroid?

Answer 3

A: They are enzymes that convert T4 to the active T3 or the inactive reverse T3 (RT3), regulating thyroid hormone activity.

Question 4

Q: What is T3, and how does it compare to T4 in terms of potency?

Answer 4

A: T3 (triiodothyronine) is about four times more potent than T4 and is active in increasing growth, metabolism, heart rate, and development.

Question 5

Q: What percentage of thyroid hormone released by the thyroid is T4?

Answer 5

A: About 90% of the thyroid hormone released by the thyroid is T4.

Question 6

Q: What is reverse T3 (RT3) and its function?

Answer 6

A: Reverse T3 is a biologically inactive form of T3 that protects tissues from excess thyroid hormones.

Question 7

Q: Which two nutrients are essential for thyroid hormone synthesis?

Answer 7

A: Tyrosine and iodine are essential, as they form the backbone of T3 and T4 synthesis.

Question 8

Q: Why is selenium important for thyroid function?

Answer 8

A: Selenium acts as a cofactor for enzymes involved in the conversion of T4 to T3 and supports antioxidant functions.

Question 9

Q: What vitamins support thyroid hormone synthesis and function?

Answer 9

A: Vitamins A, C, E, B2, B3, B6, and B12 are all supportive of thyroid synthesis and function.

Question 10

Q: List some iodine-rich foods that support thyroid health.

Answer 10

A: Sea vegetables, ocean fish, shellfish, eggs, and dairy products are rich in iodine.

Question 11

Q: What can cause iodine deficiency, increasing the risk of thyroid disorders?

Answer 11

A: Low/no dairy or fish intake, pregnancy, vegan diets, and high intake of goitrogenic foods can lead to iodine deficiency.

Question 12

Q: What is the Wolff-Chaikoff effect?

Answer 12

A: It is a response that temporarily inhibits thyroid hormone production in the presence of excess iodine, potentially leading to hypothyroidism in certain individuals.

Question 13

Q: Where does most of the T3 in circulation come from?

Answer 13

A: About 90% of circulating T3 comes from peripheral conversion of T4, not direct thyroid secretion.

Question 14

Q: What is the biological role of reverse T3 (RT3)?

Answer 14

A: RT3 is inactive but can bind to T3 receptors, blocking T3’s action when levels are elevated, especially in cases of high stress or chronic illness.

Question 15

Q: What factors can increase the conversion of T4 to RT3?

Answer 15

A: Chronic illness, high stress, deficiencies in zinc, selenium, or iron, liver dysfunction, and fasting can increase RT3 conversion.

Question 16

Q: Name some environmental disruptors that can interfere with thyroid function.

Answer 16

A: Pesticides, PCBs, bisphenols (e.g., BPA), phthalates, and perchlorates are common disruptors of thyroid function.

Question 17

Q: How does fluoride affect thyroid function?

Answer 17

A: Fluoride can interfere with iodine uptake and the conversion of T4 to T3, potentially lowering thyroid function.

Question 18

Q: What are some ways to avoid HPT disruptors?

Answer 18

A: Use filtered water, avoid fluoride toothpaste, eat organic foods, and avoid plastic packaging and farmed fish.

Question 19

Q: Which types of medications may decrease TSH secretion?

Answer 19

A: Dopamine, glucocorticoids, and lithium can decrease TSH secretion.

Question 20

Q: How do beta-blockers affect T4 to T3 conversion?

Answer 20

A: Beta-blockers can reduce the conversion of T4 to the active T3.

Question 21

Q: Why is it important to review a patient’s medication history during a thyroid assessment?

Answer 21

A: Many medications can alter thyroid function by affecting TSH secretion, T4 and T3

Question 22

Q: How does gut dysbiosis affect thyroid function?

Answer 22

A: Gut dysbiosis can negatively impact thyroid function by altering iodine uptake, thyroid hormone metabolism, and increasing inflammation in autoimmune thyroid disease (AITD) through changes in intestinal permeability.

Question 23

Q: What is a common marker of intestinal permeability associated with AITD?

Answer 23

A: Elevated zonulin levels, which are often linked to increased intestinal permeability, are commonly seen in AITD.

Question 24

Q: What are the optimal conventional medicine ranges for TSH and Free T4?

Answer 24

A: The optimal range for TSH is 0.4 to 2.5 mIU/L, and for Free T4, it is 12.8 to 19.5 pmol/L.

Question 25

Q: Which antibody tests are commonly used to diagnose autoimmune thyroid disorders?

Answer 25

A: Thyroglobulin antibodies and thyroid peroxidase (TPO) antibodies are commonly tested.

Question 26

Q: Why is it important to assess both clinical symptoms and test results in thyroid function testing?

Answer 26

A: Blood tests may not always reflect tissue levels of T3; therefore, clinical signs and symptoms are crucial for a comprehensive assessment.

Question 27

Q: What thyroid disorder is suggested by high TSH and normal T4 and T3 levels?

Answer 27

A: High TSH with normal T4 and T3 suggests subclinical hypothyroidism.

Question 28

Q: What findings are typically seen in hypothyroidism and hyperthyroidism regarding TSH, T4, and T3?

Answer 28

A: Hypothyroidism often shows high TSH with low T4/T3, while hyperthyroidism often shows low TSH with high T4/T3.

Question 29

Q: What test is commonly used to assess iodine status in the body?

Answer 29

A: A urine iodine test is commonly used to measure iodine levels.

Question 30

Q: What is the optimal urinary iodine level in children and adults?

Answer 30

A: The optimal urinary iodine level for children and adults is 100–199 mcg/L.

Question 31

Q: What does the Barnes Basal Body Temperature Test measure, and how is it performed?

Answer 31

A: It measures basal body temperature as an indicator of low thyroid function. The test is performed by taking axillary temperature daily for seven days upon waking.

Question 32

Q: What temperature reading might indicate low thyroid function in the Basal Body Temperature Test?

Answer 32

A: A waking temperature consistently below 36.5°C may indicate low thyroid function.