Week 6 Flashcards
1
Q
True or False: Majority of cases of hypothyroidism are a result of Hashimoto’s thyroiditis.
A
True
2
Q
True or False: Goitres from iodine deficiency are rare in North America.
A
True
3
Q
Where would you find most of iodine in the body?
A
Thyroid (actively concentrated)
4
Q
What does the body do to iodine that’s not used by the thyroid?
A
Excreted in the urine
5
Q
Where is iodine released after thyroxine metabolism in the liver excreted into?
A
In the bile
6
Q
What are some food sources of iodine?
A
- seafood
- sea vegetables (kelp, seaweed…)
- Iodized salt
- calcium and potassium iodide food additives in commercially produced bread
7
Q
True or False: high intake (several grams) of iodine can lead to toxicity
A
True
8
Q
Under which pathological condition would we use zinc supplement?
A
hypothyroidism
9
Q
In which physiological process is zinc involved?
A
Zinc is involved in protein/DNA/RNA metabolism
10
Q
Zinc is vital throughout life but particularly important during which periods?
A
Period of growth
11
Q
True or False: Component of several body enzymes (zinc metalloenzymes).
A
True
12
Q
Where does zinc get absorbed?
A
Small intestine
13
Q
True or False: the amount of zinc absorbed depends on the body’s current zinc levels. If zinc levels are low, the body will absorb a higher percentage of zinc to compensate.
A
True
14
Q
Consumption of what will inhibit zinc absorption?
A
Alcohol consumption can inhibit zinc absorption.
15
Q
Which part of the body will zinc be primarily stored once absorbed?
A
muscle and bone tissue
- structural or functional processes.
16
Q
What are some cautions in zinc supplementation?
A
Supplementation can result in copper deficiency and it interferes with iron absorption.
*High levels of zinc interfere with the body’s ability to absorb copper, which can lead to an imbalance if supplementation is not carefully monitored.
- Zinc can interfere with iron absorption. This means that if too much zinc is consumed, it may reduce the body’s ability to absorb iron, potentially leading to deficiencies if the diet is not balanced appropriately.
17
Q
What are some food sources of zinc?
A
Seafood (oysters highest)
Meat, eggs, milk
Legumes and whole grain
18
Q
True or False: Animal sources have higher bioavailability of zinc than plant sources
A
True
19
Q
Is copper deficiency common?
A
No
20
Q
Under which pathological condition would we use copper supplement?
A
hypothyroidism
21
Q
What are the food source of copper?
A
seafood (oysters), nuts, seeds
22
Q
Can uncoated copper cookware lead to increased copper intake?
A
Copper may leach into food when uncoated copper cookware is used. This can lead to increased copper intake.
23
Q
Under which pathological condition would we use manganese supplement?
A
hypothyroidism
24
Q
In conjunction with vitamin K, which physiological process does manganese plays a role in?
A
Blood clotting & hemostasis
25
True or False: manganese is involved in amino acid, cholesterol, glucose, and carbohydrate metabolism; reactive oxygen species scavenging (collect); bone formation; reproduction; and immune responses.
True
26
Manganese deficiency may occur with which pathological condition?
Pancreatic insufficiency
27
What is the consequence of excess accumulation of manganese in the liver and CNS?
This can lead to psychiatric disturbances and neuromuscular symptoms
28
Which factor can lead to manganese toxicity?
Environmental exposure
29
What are some food sources of manganese?
Grains
legumes
nuts and seeds
leafy vegetable
coffee and tea
30
Under which pathological condition, would chromium supplement be indicated?
Hypothyroidism
31
What are the roles of chromium under the condition of hypothyroidism?
1. part of a protein complex that potentiates (enhance) insulin activity
2. Assist with moving glucose into cell
32
what are some food resource of chromium?
1. brewer's yeast
2. liver
3. cheddar cheese
4. wheat germ
5. whole grains
33
Under which pathological condition, would selenium supplement be indicated?
Hypothyroidism
34
Where would selenium be deposited in the body?
Selenium is deposited in all body tissue except adipose tissue
35
Which organs has the highest concentrations of selenium?
Liver, heart, kidney and spleen
36
True or False: Selenium is integral to selenoproteins such as glutathione peroxidase and deiodinase
True. Selenium is a key component of selenoproteins, which include important enzymes like glutathione peroxidase and deiodinase These selenoproteins are critical for maintaining cellular health and regulating metabolism
37
True or False: Glutathione peroxidase works in conjunction with vitamin E
True. Glutathione peroxidase + vitamin E can neutralize harmful free radicals, protecting cells from oxidative stress and damage.
38
What are the food resources of selenium?
Brazil nuts
seafood
legumes
whole grains
lean meats
dairy products
39
Under which pathological condition would supplement of fluoride be indicated?
Hypothyroidism
40
Where does fluoride accumulate in the body?
Fluoride accumulates in calcified tissues.
*Fluoride tends to concentrate in tissues that have undergone calcification, such as bones and teeth. This makes fluoride crucial in the development and maintenance of these tissues.
41
True or False: fluoride is important during growth of calcified tissue where incorporation of fluoride results in resistance to resorption.
True.
* During the growth of calcified tissues (like bones and teeth), the incorporation of fluoride helps make these tissues more resistant to resorption (breakdown) and absorbed by the body. This resistance is particularly beneficial in preventing the breakdown of teeth and bones.
42
True or False: Fluoride-containing crystals are more resistant to bacterial acids.
True. Fluoride strengthens the structure of teeth by forming fluoride-containing crystals, which are more resistant to bacterial acids that cause tooth decay. This property is why fluoride is commonly used in dental products, as it helps to protect teeth from cavities and decay by making enamel more resilient
43
What's the consequence of excessive intake of fluoride?
Pitted and discolored teeth
44
What are the food sources of fluoride?
1. Fish and fish products
2. Tea
3. Consumption of fluoridated dental product
4. Fluoridated water supplies
45
What are the characteristics of patient with hypothyroidism (metabolic rates/energy needs/weight/fluid) ?
1. slower metabolic rates
2. lower energy needs
3. weight gain
4. fluid retention
46
What's the therapeutic considerations?
1. Adjust caloric intake to prevent unnecessary weight gain. The caloric intake should be tailored to their slower metabolic rate and energy needs.
2. ensure iodine and selenium intake are sufficient
3. incorporate iodine and selenium-rich foods
4. avoid excessive iodine intake in those already medicated.
47
What does goitrogen do?
1. goitrogen interfere with thyroid hormone production .
They disrupt the normal production of thyroid hormones by interfering with iodine uptake or by disrupting hormone synthesis in the thyroid gland.
2. Usually exert their effect after prolonged use and have a greater effect when iodine intakes are low.
Their effect is more pronounced when iodine intake is insufficient because the thyroid needs iodine to produce thyroid hormones. Without enough iodine, the thyroid is more vulnerable to goitrogenic interference as goitrogen trigger pituitary to release TSH which promotes growth of thyroid tissue --> goiter.
3. Many are naturally found in food such as thiocyanates, glucosinolates ---> cruciferous vegetables (e.g., cabbage, broccoli, cauliflower), some flavonoids ---> plant-based foods.
48
True or False: Cassava, lima beans, linseed, sorghum, and sweet potato contain cyanogenic glycosides that are metabolized to thiocyanates.
Thiocyanates interfere with iodine uptake in the thyroid gland by competing with iodine
True.
49
True or False: Soy and millet contain flavonoids that impair thyroid peroxidase activity.
True. Flavonoids that can inhibit the activity of TPO which is critical for thyroid hormone synthesis. By impairing TPO activity, these flavonoids can reduce the production of thyroid hormones.
50
True or False: Cruciferous vegetables contain glucosinolates and their metabolites compete with iodine for thyroidal uptake.
True.
51
Should we avoid food sources that contains goitrogens?
No. Most goitrogens are reduced by cooking the food sources. So food sources are generally considered healthy and should not specifically be avoided.
52
Ture or False: Appropriate thyroid function is needed for vitamin A metabolism.
True. The thyroid gland helps regulate the conversion of carotenoids (precursors of vitamin A) into their active form, retinol, which is essential for various bodily functions, including vision, immune function, and skin health.
53
True or False: lower body level of vitamin A is possible in those with hypothyroidism.
True. Individuals with hypothyroidism may have reduced levels of VA in their body. This occurs because the thyroid hormone is involved in converting carotenoids into active VA, and without sufficient thyroid hormone, this process is less efficient
54
True or False: patient with hypothyroidism should consider food sources of carotenoids.
True. It’s recommended to consider dietary sources rich in carotenoids, such as carrots, sweet potatoes, and leafy greens. These foods contain precursors that the body can convert to vitamin A, although this conversion may be slower in individuals with hypothyroidism.
55
Which of the following trace minerals are directly involved in thyroid metabolism and function?
A. Chromium and zinc
B. Zinc and iodine
C. Iodine and selenium
D. Selenium and chromium
C. Iodine and selenium
56
What are the difference between thyrotoxicosis and hyperthyroidism?
Thyrotoxicosis: any condition leads to excess thyroid hormone in the body and its subsequent effects, regardless of the source (i.e. taking too much thyroid hormone medication or thyroid hormone release from a damaged thyroid gland)
Hyperthyroidism: a specific cause of thyrotoxicosis that occurs due to the overproduction of thyroid hormones by the thyroid gland itself.
57
What is the life-threatening medical emergency when there's severe thyrotoxicosis ?
Thyroid storm
58
What is a more common thyrotoxicosis presentation in typical naturopathic practice?
Hyperthyroidism
59
When should we consider thyroid surgery?
When there's limitations of medication and the potential for the formation of goitre.
60
What is the common and likely adverse effect of thyroid surgery?
Hypothyroidism
61
What is iodine 131 and what does it do?
Iodine 131 is a radioactive iodine and used to ablate thyroid tissue in patients with Graves's disease and toxic nodules.
* Iodine 131 destroys overactive thyroid cells, helping to reduce thyroid hormone production and alleviate hyperthyroidism
62
Would iodine 131 affect the rest of the body?
1. The thyroid rapidly concentrates iodine, so an oral dose has minimal effect on the rest of the body.
*The thyroid gland has a unique ability to absorb iodine quickly, which makes this treatment effective. After a patient takes an oral dose of radioactive iodine, the iodine is concentrated in the thyroid, minimizing exposure to other parts of the body.
2. Beta wave emission destroys surrounding tissue within a range of 0.6 – 2 mm
*The beta waves emitted by Iodine-131 have a short range (0.6 to 2 mm), which allows the radioactive iodine to selectively destroy thyroid cells without significantly affecting surrounding tissues or other parts of the body.
63
What are the adverse effects of radioactive iodine treatment?
1. High risk of hypothyroidism
*Because the treatment destroys thyroid tissue, it often reduces the gland’s ability to produce enough thyroid hormone, leading to an underactive thyroid. Most patients will need lifelong thyroid hormone replacement therapy after this treatment.
2. Possible worsening of Graves' orbitopathy.
* Graves' orbitopathy is an eye condition associated with Graves' disease. This worsening is more common in patients who already have moderate to severe eye symptoms.
3. Risk of radiation thyroiditis
*An inflammation of the thyroid gland caused by the radiation from the treatment. This can lead to symptoms such as neck pain, swelling, fever, or temporary worsening of hyperthyroidism symptoms due to the release of stored thyroid hormones as the gland is destroyed.
64
Does methimazole affect stored thyroid hormone or thyroid hormone in circulation?
No. Methimazole only prevents the production of new thyroid hormones but does not affect the thyroid hormones that have already been produced and are stored in the thyroid gland, or those that are already circulating in the bloodstream.
*The effects of the drug may take some time to be fully realized, as the body uses up its existing thyroid hormone stores.
65
Does methimazole interfere with iodination of tyrosine as well as with coupling?
Yes.
* Iodination of tyrosine: This refers to the process where iodine is added to the amino acid tyrosine, which is necessary for the formation of thyroid hormones.
*Coupling: Methimazole also blocks the process where two iodinated tyrosine molecules combine to form T3 and T4.
66
What are some adverse effect of methimazole?
1. Skin rash/allergic reaction/agranulocytosis (where the body has an extremely low count of white blood cells, which can impair the immune system and lead to serious infections)
2. Hepatotoxicity (rare). it is important to monitor liver function during treatment to prevent any serious complications related to liver health.
3. Contraindication during first trimester of pregnancy due to causing aplasia cutis.
*a rare congenital defect in which patches of skin are absent at birth
67
Does propylthiouracil affect the production of thyroid hormone and existing thyroid hormone?
Yes.
1. similar mechanism to methimazole--->preventing the thyroid gland from producing excess amounts of T3 and T4.
2. inhibit conversion of T4 to T3 in the periphery (outside the thyroid). This makes PTU particularly useful in rapidly lowering thyroid hormone levels in certain situations, such as during a thyroid storm.
68
What is the difference in adverse effects between propylthiouracil and methimazole?
Propylthiouracil does not cause aplasia cutis.
Propylthiouracil still causes:
1. skin rash/allergic reaction/agranulocytosis
2. hepatotoxicity
69
In most instances, is methimazole or propylthiouracil the preferred drug?
Methimazole is the preferred drug in most instances due to the lower risk of causing hepatotoxicity.
70
When the patients are breastfeeding, should methimazole or propylthiouracil be indicated?
Methimazole
71
When the patients is children, should methimazole or propylthiouracil be indicated?
Methimazole
72
When the patient is during her first trimester of pregnancy, should methimazole or propylthiouracil be indicated?
Propylthiouracil
73
Under the condition of thyroid storm, should methimazole or propylthiouracil be indicated?
Propylthiouracil
74
What does beta blockers do and does it affect thyroid hormone production?
No. Beta blockers do not interfere with the actual production of thyroid hormones.
Beta blockers help reduce the symptoms of adrenergic excess, which are caused by the overstimulation of the nervous system due to high thyroid hormone levels. Symptoms include elevated heart rate, hypertension, etc.)
75
What is propranolol and what does it do?
Propranolol is a type of beta blocker. It reduce the conversion of T4 to T3 in the periphery.
76
What are the adverse effects of beta blockers?
1. Bradycardia
Beta blockers can slow the heart rate (bradycardia), which can be beneficial in hyperthyroidism but may lead to excessively slow heart rates in some individuals.
2. dizziness
Reduced heart rate and blood pressure can cause dizziness, especially when standing up quickly (postural hypotension).
3. fatigue
Beta blockers can reduce energy levels, leading to feelings of tiredness or lethargy.
4. headache
5. hypotension
Beta blockers can lower blood pressure (hypotension), which can be problematic if the blood pressure becomes too low, resulting in weakness or fainting.
77
What is the contraindication of using beta blockers?
Avoid in patients with asthma or conditions associated with bradycardia.
* Beta blockers can constrict the airways, worsening asthma symptoms.
*Beta blockers should be avoided in individuals with conditions that involve a naturally slow heart rate (bradycardia) as beta blockers could further reduce heart rate to dangerous levels.
78
When should beta blockers be tapered off?
Once the symptoms of thyrotoxicosis (excessive thyroid hormone levels) improve.
*Gradual tapering is important to avoid rebound effects, such as increased heart rate or blood pressure after stopping the medication.
78
What is the most common cause of hypothyroidism in North America?
Hashimoto's thyroiditis
79
What is the standard therapy for treating hypothyroidism in pharmacology?
Levothyroxine
80
What is the mechanism of levothyroxine?
Levothyroxine is a replacement therapy as it replaces the thyroid hormone that the body is not producing in sufficient amounts----T4 (the body converts into the active form T3 as needed)
81
After dosage adjustment of levothyroxine, how long dose it take to attain a new steady state?
When levothyroxine dosages are adjusted, it typically takes about 6 weeks for the body to reach a new steady state of thyroid hormone levels.
*TSH should be rechecked after this period to assess the effectiveness of the new dose.
82
What determines the initial doses of levothyroxine?
Depend on endogenous thyroid function, the existing level of thyroid function
83
Ture or False: In patients with an intact thyroid or with mild or subclinical disease (Patients who still have some thyroid function), much smaller initial dosages may be needed.
True.
84
True or False: In patients with negligible thyroid function full replacement dosages may be needed.
True.
*patient that has little to no thyroid function
85
what can interfere the absorption of levothyroxine ?
1. Antacids and mineral supplementation.
* Antacids (e.g., calcium carbonate) and mineral supplements (such as iron or calcium), leading to reduced effectiveness. It's important to avoid taking these together
2. Proton pump inhibitors and estrogens
*PPI reduce stomach acid & estrogen interfere with the absorption of levothyroxine.
3. levothyroxine can interact with anticoagulant drugs, increase the effect of the anticoagulant.
86
What are some adverse effects of levothyroxine?
1. hyperthyroidism if too much levothyroxine is given.
2. Worsen symptoms such as angina (chest pain due to reduced blood flow to the heart).
*if the dose leads to excessive thyroid hormone levels, which can increase the heart’s demand for oxygen.
3. Decline in glycemic control. For patients with diabetes, antihyperglycemic medications need to be adjusted.
87
What is the alternative treatment for hypothyroidism besides levothyroxine?
Desiccated thyroid which contain T3 and T4 in a fixed ratios.
*it is derived from the thyroid glands of animals (typically pigs).
88
What are the adverse effects of desiccated thyroid?
Cardiovascular and neurological adverse effects increases with larger doses (due to T3)
- palpitation, tachycardia, cardiac arrhythmias, angina pectoris
- nervousness, tremors, headache, insomnia
- sweating, heat intolerance, fever, weight loss
