Hypothyroidism Flashcards
1
Q
Hypothyroidism classification
A
- Primary: Pathological processes are within the thyroid gland. TSH is higher due to low T4 and T3 (e.g., iodine deficiency, autoimmune, viral infections, drug induced, postpartum).
- Secondary: Pathological processes are within the pituitary gland — inadequate TSH to signal the thyroid gland to release more hormones. TSH is low (hypopituitarism).
- Tertiary: Inadequate TRH (hypothalamic disease).
- Peripheral: Insensitivity to thyroid hormones.
- Subclinical: TSH is slightly elevated and T4 is normal. T4 to T3 conversion issues, ↑ RT3 or thyroid cell receptor resistance.
2
Q
Hypothyroidism - General signs and symptoms:
A
General signs and symptoms:
- Fatigue.
- Weight gain / inability to lose weight
- Heavy or irregular menstrual periods
- Puffy face, swollen eyelids, oedema
- Intolerance to cold, cold extremities
- Joint and muscle pain / weakness
- High cholesterol (usually LDL)
- Dry skin, elbow keratosis, brittle nails
- Hair loss / thinning of hair and eyebrows
- Brain fog / concentration problems
- Depression
- Easy bruising
- Constipation
- Gas / bloating
- Headaches
- Low libido
- Fertility problems
- ↑ miscarriage risk
- Goitre
- Bradycardia
- Carpal tunnel syndrome
3
Q
Subclinical hypothyroidism (SCH)
A
- Elevated TSH levels with normal free T4 levels. Often undetected (up to 10% of the population) and requires naturopathic support.
- Linked to an increased risk of heart failure, coronary artery disease events and infertility. Fertility improves and miscarriage risk reduces when addressed.
- It can cause cognitive impairment, fatigue, and altered mood.
- Higher serum TSH levels (> 10 mU / L) and thyroid autoantibodies, increase the risk of SCH progression to overt hypothyroidism.
- Optimal status is a TSH of 2.5 or less.
4
Q
Hypothyroidism - Causes and risk factors
A
- Iodine deficiency or iodine excess (in susceptible individuals) — see earlier, including goitrogens.
- Women — more common in women, possibly due to increased rates postpartum, during and post menopause. Autoimmunity is also higher in women.
- Increasing age (peak in 4th decade).
- Drug induced: E.g., amiodarone and lithium.
- Congenital — absence / underdevelopment of thyroid gland and enzymes required for hormone synthesis and iodide transfer.
- A lack of other nutrients (i.e., tyrosine, iron, selenium, zinc, vitamin D, vitamins C, E, B2, B3, B6, B12, copper).
- Postpartum thyroiditis — autoimmune thyroiditis which flares as a result of immunologic ‘rebound’ from the relative immunosuppression of pregnancy.
- Chronic stress — inhibits TSH release, ↓ D1 ↓ T3, ↓ thyroid hormone receptor sensitivity and ↑ RT3. Also = immunological shift from Th1 to Th2 — predisposing to AITD.
- Infection/inflammation – inflammatory conditions or viral infections 27 can = transient hyperthyroidism followed by transient hypothyroidism
- Alcohol — directly suppresses thyroid function, indirectly blunts TRH response. Chronic use can reduce peripheral thyroid hormones.
- Smoking — Cyanide in cigarettes is converted to thiocyanate during its detoxification, which disrupts iodine absorption.
- Post-ablative therapy or surgery — thyroid damage can occur after thyroid or other neck surgery, radioiodine therapy.
- Hereditary link — 23.6% of mothers with children with Hashimoto’s thyroiditis had a history of thyroid dysfunction
5
Q
Hashimoto’s thyroiditis (HT)
A
Hashimoto’s thyroiditis (HT) = an autoimmune disease that attacks thyroid tissue causing reduced thyroid hormones.
- Female-to-male ratio is at least 10:1.
- ↑ TSH, low FT4, ↑ antithyroid peroxidase (TPO) antibodies.
- Anti-thyroglobulin (anti-Tg) and TSH receptorblocking antibodies (TBII) may also be present.
- EBV and H. pylori are often implicated.
- Early disease: Individuals often exhibit signs and symptoms with tests revealing hyperthyroidism or normal values due to the intermittent nature of destruction of thyroid cells.
- HT is often diagnosed late.
6
Q
Hashimoto’s thyroiditis (HT)
A
Hashimoto’s thyroiditis (HT) = an autoimmune disease that attacks thyroid tissue causing reduced thyroid hormones.
- Female-to-male ratio is at least 10:1.
- ↑ TSH, low FT4, ↑ antithyroid peroxidase (TPO) antibodies.
- Anti-thyroglobulin (anti-Tg) and TSH receptorblocking antibodies (TBII) may also be present.
- EBV and H. pylori are often implicated.
- Early disease: Individuals often exhibit signs and symptoms with tests revealing hyperthyroidism or normal values due to the intermittent nature of destruction of thyroid cells.
- HT is often diagnosed late.
7
Q
Hashimoto’s thyroiditis — causes and risk factors
A
Hashimoto’s thyroiditis — causes and risk factors:
- Excess iodine — highly iodinated thyroglobulin is more immunogenic.
- Genetic polymorphisms — VDR, MTHFR (link to AITD).
- HT often co-exists with coeliac disease. Gluten-free diets have been shown to reduce antibody titres.
- Sleep apnoea and HT may influence each other.
- Heavy metals — mercury, lead, cadmium ↑ TGO antibodies.
Metallothioneins (selenocysteine) in the thyroid bind to cadmium.
- Triclosan — found in personal care products e.g., toothpastes. Resembles structure of thyroid hormones.
- ↑ pro-inflammatory cytokines e.g., IL-6, TNF- α, IL-12, IL-10
8
Q
Hashimoto’s thyroiditis - Allopathic treatment
A
- 1 st line treatment: Levothyroxine (synthetic T4).
Doses range from 25 to 200 mcg daily.
- Medication failure is often due to conversion problems e.g., nutrient deficiencies — where nutrition is key.
- Due to many interactions, take levothyroxine on an empty stomach in the morning. Food / drinks / other drugs taken 1 hour or more later.
- Drug absorption is affected by factors such as coeliac disease, atrophic gastritis, coffee and PPI use.
- By altering thyroid results, levothyroxine dose should be reviewed under the supervision of the client’s GP
9
Q
Hashimoto’s thyroiditis - Common triggers & mediators
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10
Q
Hashimoto’s thyroiditis - Naturopathic approach
- Address triggers and mediators (identify the cause!):
A
- Address triggers and mediators (identify the cause!):
- Optimise micronutrient status — support T4 to T3 conversion (see following slides). Review iodine status (low / excess). Consider nutritive herbs such as nettle (e.g., nettle tea).
- Optimise digestion — e.g., digestive bitters, enzymes etc.
- Support methylation — folate, B12, B6, B2, choline, betaine, zinc. Consider genetic testing.
- Remove thyroid disruptors
- Address possible dysbiosis/SIBO — common in HT (see GI health).
- Address stress, support HPA axis (positively influences HPT).
- Assess for pathogens (e.g., stool test) and heavy metals / environmental toxins (e.g., GPL-Tox, hair toxin analysis).
- Heavy metals — avoidance; use natural chelators, e.g., coriander and chlorella.
- Support detoxification and elimination (HT sufferers are often poor detoxifiers) — e.g., B vitamins, ↑ glutathione (NAC, milk thistle, resveratrol, etc.), flavonoids, carotenoids, fibre, chlorophyll (green juice).
- Support SCFA-producers (e.g., pro/prebiotics, fibre, polyphenols)
- Assess for coeliac disease (total IgA should be included with TtgA). Higher incidence in AITD.
- Identify food intolerances (gluten, wheat. lactose etc.) and cross-reactive foods (e.g., Elimination diet / Autoimmune Paleo diet).
- Increase exercise. Identify and manage sleep disorders. Sleep apnoea and HT have a bi-directional influence.
11
Q
Hashimoto’s thyroiditis - Naturopathic approach
- Reduce inflammation and IR
A
- Reduce inflammation and IR:
- Optimise omega-3:6 ratio, avoid trans fats, sugar, alcohol, high GL foods, smoking, limit arachidonic acid (Hs-CRP < 1).
- Blood sugar balance and improve insulin sensitivity (low GI / GL foods, cinnamon, chromium etc.).
- ↑ antioxidant sources to ↓ oxidative stress.
12
Q
Hashimoto’s thyroiditis - Naturopathic approach
- Reduce goitrogenic compounds
A
- Reduce goitrogenic compounds:
- Pre-soaking, steaming or boiling reduces goitrogens.
Cooking destroys goitrogens by stimulating the production of myrosinase, an enzyme that helps deactivate goitrogenic glucosinolates. It is beneficial to still include these foods
13
Q
Hashimoto’s thyroiditis - Naturopathic approach
- Balance T-cell functioning (Th1 / Th2 / Th17 / T-reg cell balance)
A
- Balance T-cell functioning (Th1 / Th2 / Th17 / T-reg cell balance):
* Address increased intestinal permeability: Critical for immune tolerance, T-reg cells (maintain tolerance). ↑ glutamine (10 g BID), aloe, zinc carnosine, vit A, D, EPA and DHA (3–4 g), curcumin.
- Commensal bacteria produce butyrate (e.g., roseburia, Akkermansia spp.) — supports T-reg cells. Raise through pre and probiotic foods / supplements; optimising dietary fibre; focusing on a rainbow of colour for the polyphenols.
- Support SIgA levels (probiotics including S. boulardii, zinc, A, D, omega-3, colostrum) for immune tolerance and reduced food reactions.
14
Q
Hypothyroidism - Nutritional support:
Selenium (Se)
A
15
Q
Hypothyroidism - Nutritional support:
Zinc
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16
Q
Hypothyroidism - Nutritional support:
Iron
A
17
Q
Hypothyroidism - Nutritional support:
Iodine
A
18
Q
Hypothyroidism - Nutritional support:
Vitamin A
A
19
Q
Hypothyroidism - Nutritional support:
Tyrosine
A
20
Q
Hypothyroidism - Nutritional support:
Vitamin D
A
