Hypothyroidism Flashcards
(24 cards)
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
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
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.
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
Subclinical hypothyroidism (SCH):
- 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.
Causes and risk factors:
- Iodine deficiency or iodine excess
- Women
- Increasing age
- Drug induced
- Congenital
- A lack of other nutrients
- Postpartum thyroiditis
- Chronic stress
- Infection/inflammation
- Alcohol
- Smoking
- Post-ablative therapy or surgery
- Hereditary link
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 receptor blocking antibodies (TBII) may also be present.
* EBV and H. pylori are often implicated.
HT: 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.
Naturopathic approach to hypothyroidism
- Address triggers and mediators (identify the cause!)
- Reduce inflammation and IR
- Reduce goitrogenic compounds
- Balance T cell functioning ( Th1 / Th2 / Th17 / T reg cell balance)
Address triggers and mediators
- Optimise micronutrient status support T4 to T3 conversion. 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
- 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.
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.
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.
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.
Hypothyroid: Supplements
Selenium
Zinc
Iron
Iodine
Vitamin A
Tyrosine
Vitamin D
Selenium
- Antioxidant, anti inflammatory , ↑ T3.
- Selenoenzymes : Glutathione peroxidases (GPX), thioredoxin reductases (TR), deiodinases and selenoprotein P play key roles in thyroid function.
- Narrow therapeutic range excessive levels may enhance the effects of iodine deficiency, while proper supplementation may alleviate iodine excess.
*↓ inflammatory cytokines and thyroid antibodies.
Supplement dosage of selenomethione : 150-200 mcg /day
Zinc
- Co factor of D2 and has a role in TRH synthesis.
- DNA binding component of thyroid receptors chelates zinc ions, forming ‘zinc fingers’ which mediate specificity in binding to T3 response elements (TRE) to activate transcription factors.
- Zinc deficiency is associated with enhanced expression of hepatic D1 , which ↑ thyroid hormone
- Low levels of free T3 and normal T4, but elevated RT3 are associated with mild to moderate zinc deficiency.
Supplement dosage:
15-30 mg / day
Iron
- TPO is a haem-containing enzyme used in the initial steps of hormone synthesis (adds iodine to thyroglobulin).
- Iron deficiency anaemia decreases : T4 and T3, peripheral conversion of T4 to T3 and hepatic deiodinase.
- Iron deficiency anaemia blunts the efficacy of iodine supplementation.
- Iron supplementation (correction) has been shown to reduce RT3 and increase T3 and T4 in adolescent girls.
Supplement dosage: Approx. 10mg maintenance, 30 mg/day if deficient, check levels before
Iodine
- Decreases response of the thyroid to TSH, but at high concentrations, inhibits thyroid hormone secretion.
- Modulates thyroid response to TSH ( -ve feedback).
- If unsure, urinary iodine loading test to assess status.
- Huge variability in iodine content in kelp / seaweed, foods, and supplements, and in absorption of
topically applied Lugol’s iodine avoid taking alongside iodine supplements (additive effect). Although Lugol’s should not be advised orally as it is not a food supplement.
Supplement dosage: 150-400 mcg baseline to optimal dose).
DO NOT use in AITD, hyperthyroid or thyroxine use).
Vitamin A
- Deficiency increases TSH. Supplementation can reduce TSH and increase T3.
- Deficiency reduces iodine uptake in thyroid .
- Via its role in retinoic acid receptors (RAR), vitamin A modulates thyroid hormone receptor function.
- Insufficiency from low intake or BC01 SNPs.
Supplement dosage: 2000 IU
Tyrosine
- Thyroglobulin precursor and supports stress adaptation short term.
- Avoid high doses long term and with thyroxine use.
Supp. dosage: 200-500 mg
Vitamin D
- Deficiency is significantly higher in those with AITDs.
- Levels inversely correlated with thyroid antibodies.
- Immune modulatory role (T-reg cells).
- Supplementation found to be beneficial even in those with ‘normal’ levels.
- Aim for vitamin D levels of 100-150 nmol / L.
Supplement doses:
2000 IU (or more)
Antioxidants and Other
Antioxidants: Vitamins C, E, cysteine, glutathione.
Other: Copper (deiodinase cofactor), B2, B3 (energy metabolism).
