Hypothyroidism

DESCRIPTION

Hypothyroidism refers to low function of the thyroid, an endocrine gland located in the front of the neck, just below the larynx (voice box). Through its production of thyroid hormones (T4 and T3), the thyroid gland activates over 100 cellular enzymes responsible for a multitude of functions in every cell of the body. Excessive secretion of thyroid hormones can increase metabolic rate up to 100% above normal, while if no thyroid hormone is produced, a 40% drop in metabolic activity can quickly occur. In most cases of hypothyroidism, thyroid function is simply less than optimal, but this results in a slowing down of cellular functions and a buildup of metabolic wastes in all body systems.

Hypothyroidism ranges from a barely detectable (subclinical) lessening in thyroid hormone production and/or activity to a severe life-threatening deficiency state called myxedema.

The thyroid gland is not an isolated entity, but is part of a web of bodily systems whose other primary actors include: the hypothalamus, the pituitary, the liver, the kidneys, the adrenal glands, and a network of hormone-like substances called cytokines. Impairment in the activity of any of these components of the thyroid system may be an underlying cause of an individual’s low thyroid activity.

The thyroid produces two main hormones: T4, which is much less active, and T3, the hormone that primarily regulates the metabolic machinery inside cells. The production of T4 and T3 is closely controlled by the thyroid’s two supervisors, the pituitary and hypothalamus, two endocrine glands that are located in the brain. When T3 levels in the blood drop, the hypothalamus secretes thyrotropin-releasing hormone (TRH), which in turn signals the pituitary to secrete thyroid-stimulating hormone (TSH). As its name implies, TSH stimulates the thyroid gland to combine iodine with the amino acid tyrosine, thus producing about 90% of the body’s T4 together with about 10% of its T3. (T4 is tyrosine plus four iodine molecules, while T3 is tyrosine plus three iodine molecules.)

If, for some reason, the hypothalamus does not secrete TRH, the pituitary has a fail-safe system. The pituitary double-checks the hypothalamus by sampling the level of T3 in its own circulation when it converts inactive T4 into T3 in its own cells. If its T3 levels drop, the pituitary gland will secrete TSH, thus triggering the production and release of T4 by the thyroid to quickly rectify this situation. Once T4 is in the blood, another physiologic network takes over, and, with the aid of cortisone, a hormone secreted by the adrenal gland, T4 is converted to T3 in the peripheral tissues, primarily the liver and kidneys, and sent into the bloodstream. Although in the circulation, T3 is still not home free.

Its final target, where it actually affects metabolic functioning, is the interior of cells. To get inside the cells, T3 has to pass through the cellular membranes and, by connecting with the correct receptor sites, gain entry into the mitochondria (the tiny organs in each cell where energy is produced) and/or the cell nucleus.

Lastly, proper thyroid function faces one other potential roadblock: cytokines. Cytokines are hormone-like substances secreted by various types of cell that direct immune responses and act as messengers in cell-to-cell communication. Some cytokines directly affect the hypothalamic–pituitary–thyroid axis and are also capable of blocking the conversion of T4 to T3.

What else can go wrong? If levels of iodine in the diet are inadequate, the thyroid cannot produce T4. In this situation, the thyroid typically enlarges, swelling into a goiter, a characteristic sign of hypothyroidism in the developing world where iodine deficiency is common. Long-term stress, which uses up the adrenal glands’ reserve of cortisone, may cause a problem. Even if the thyroid gland produces sufficient amounts of T4, so that blood tests of T4 levels (the test commonly used to evaluate thyroid activity) appear normal, if no cortisol is available for use in the liver and kidneys to convert T4 to T3, metabolism will slow down. Excessive levels of cytokines may also be the culprit here, as certain cytokines prevent the conversion of T4 to T3.

If a blood test finds low levels of T4 along with low levels of TSH, this suggests that the pituitary is not doing its job. If, however, blood levels of TSH are elevated and T4 levels are still low, this indicates that the pituitary has responded properly, but that the thyroid gland is not following the directions provided by TSH. If T3 levels are adequate, this suggests one of three possibilities: cellular membranes could be malfunctioning so T3 cannot gain entry into the cells; T3 could be just slightly malformed, so it cannot gain entry into the cell or, if it can gain entry to the cell, it cannot attach to the appropriate receptor sites once inside; or the receptor sites inside the cells are not functioning properly.

To sum up, hypothyroidism may be due to:

• (1) inadequate T4 synthesis, either because the pituitary is not secreting TSH or because the thyroid gland is not responding to TSH and making T4;
• (2) inadequate conversion of T4 to T3 in peripheral tissues;
• (3) an inability of T3 to gain entry to the interior of cells because of a problem with cell membranes; or
• (4) an inability of T3 to attach to receptors inside the cells and activate enzymes.

Factors that may contribute to these four potential causes of hypothyroidism are discussed below.

It is estimated that a great many individuals have some disorder in their thyroid function, but more than half are undiagnosed, since many people mistake the signs of hypothyroidism for aging-associated declines. Mild thyroid failure occurs in 4–17% of women and 2–7% of men, with the risk increasing with age. The elderly are most susceptible, but hypothyroidism can affect people of all ages, even infants. One in 4,000 infants is born with congenital hypothyroidism. If blood levels of T4 are used as the only criterion,between 1 and 4% of the adult population has moderate to severe hypothyroidism, and another 10–12% has mild hypothyroidism. If, in addition to blood thyroid (T4) levels, medical history, physical examination, and basal body temperature are used, the true incidence of hypothyroidism ranges somewhere near 25% of the population – about 20% of those affected being women and 5% men.

FREQUENT SIGNS AND SYMPTOMS

• Low basal body temperature (the temperature of the body at rest):
• body temperature reflects metabolic rate which is largely determined by thyroid hormones.
• should be between 36.4 – 36.7 degrees C  ( 97.6 F or 98.2?F).
• to check basal body temperature, shake down a thermometer to below 95?F and place it by the bed
  before going to sleep. Upon waking, place the thermometer under the armpit for a full 10 min or under the tongue if digital and wait until it beeps. Remain as still as possible, resting with the eyes closed. Record the temperature for at least three consecutive mornings, preferably at the same time of day.
• menstruating women must perform the test on the second, third, and fourth days of menstruation. Men and postmenopausal women can perform the test on any three consecutive days.

Common Signs and Symptoms of Hypothyroidism

• Chronic lethargy, fatigue, weakness
• Overly sensitive to cold (cold hands or feet)
• Elevation in cholesterol and triglyceride levels: this greatly increases the risk of cardiovascular disease
• Muscle and joint aches
• Headaches
• Moderate weight gain, despite diminished appetite, and difficulty losing weight: hypothyroid patients generally show a moderate weight increase of 2–5 kg (5–10 lb), mainly from edema (fluid accumulation)
• Constipation
• Recurrent infections
• Loss of libido
• Heavy menstrual bleeding and shorter menstrual cycle (the time between periods) in premenopausal women
• Infertility
• Miscarriages, premature deliveries, stillbirths
• Rough, dry skin covered with fine, superficial scales
• Coarse, dry, brittle hair
• Thin brittle nails with transverse grooves
• Slight impairment of concentration and memory
• Depression
• Shortness of breath
• Impaired kidney function

Symptoms indicating significant thyroid dysfunction

• Edema resulting from increases in capillary permeability and slow lymphatic drainage
• Hardening of the arteries as a result of the increase in cholesterol and triglyceride levels
• Hypertension, reduced heart function, reduced heart rate
• Husky voice
• Numbness of arms and legs
• Muscle pain and weakness, causing carpal tunnel syndrome in some cases
• Joint stiffness, pain and tenderness
• Hearing loss
• Depression
• Mental confusion, difficulty concentrating, extreme forgetfulness/memory problems, especially in the elderly
• Unsteadiness
• Daytime sleepiness
• Obstructive sleep apnea: tissues in the upper throat collapse at intervals during sleep, blocking the passage of air
• Myxedema – a round puffy face, sleepy appearance, dry rough skin, loss of hair

Symptoms associated with pituitary tumour

• Any of the above symptoms
• Lowered sexual drive, impaired fertility
• Decreased adrenal gland function resulting in exhaustion, low blood pressure, salt craving
• Headaches and visual disturbances directly related to the pituitary tumour
  

CAUSES

• Overtreatment of hyperthyroidism (excessive thyroid activity): surgery, drugs and/or radiation can damage the thyroid resulting in hypothyroidism.
• Disorders of the pituitary or hypothalamus glands (rare)
• Inadequate intake of iodine: T4 is made when the thyroid gland adds iodine to the amino acid tyrosine; if the diet is deficient in iodine, the body cannot manufacture T4:
• in developing nations worldwide, 200 million people have goiters. In all but 4% of these cases, the goiter is due to iodine deficiency.

• Excessive iodine: too much iodine inhibits the conversion of T4 to T3:
• in developed nations such as the US where iodine has been added to salt, iodine deficiency is quite rare, yet some people still develop goiters. In these people, the goiter may be due to excessive consumption of foods, called goitrogens, that block iodine utilization (rare) or to nutrient deficiency (see below).
• goitrogens include Brassica family foods (turnips, cabbages, rutabagas, mustard greens, radishes, horseradishes), cassava root, soybeans, peanuts, pine nuts, and millet.
• cooking, however, usually inactivates goitrogens.
• Deficiency in nutrient cofactors necessary for T4 production: zinc, copper, vitamins A, B2, B3, B6,and/or C.
• Deficiency in nutrient cofactors necessary for conversion of T4 to T3: selenium, zinc.
• Impaired cellular response to T3: due to iron or zinc deficiency, physical inactivity.

• Metals and heavy metals, including lead, mercury, dental amalgams: these metals can cause alterations in cellular membranes and receptor sites, thus preventing T3 from gaining entry to the cell’s interior or mobilizing enzymes once inside:
• the destructive effects of heavy metals on the endocrine organs, including the thyroid gland, are well documented. Both lead and mercury (dental amalgams are 50% mercury, and the teeth are only a short distance from the thyroid gland) commonly invade the thyroid gland and interfere with the production of thyroid hormones, or induce minute alterations in their molecular structure, so that the hormones are no longer recognized by, and admitted into, cells.
• heavy metals can also impair liver and kidney function, thus decreasing conversion of T4 to T3.

• Stress: chronic stress may result in a state of adrenal exhaustion in which supplies of cortisone are depleted. Cortisone is necessary for the conversion of T4 to T3 in the liver and kidneys. Sources of stress  may be emotional as well as physical, including head or body injury, chronic allergies or infections, anxiety, poor diet, lack of sleep.

• Pesticide-contaminated water exposure: tap water can be contaminated with low levels of insecticides, weed killers, and artificial fertilizer. Pesticides have been shown to interfere with thyroid function and to increase cancer risk:
• people not only drink and cook with water, but also bathe and shower in it, thus absorbing chemicals through the digestive tract, skin and by breathing in the vapors, through the lungs.
• the likelihood of pesticide contamination of water is highest in agricultural areas.

• Fluoride: it is well documented that fluoride is a direct antagonist to, and therefore inhibits utilization of, iodine. Although fluoridation of water supplies is controversial, many experts believe fluoride, like mercury, is a chemical toxin that should be avoided.

• Xenobiotics: the term xenobiotic is used to describe toxins that come into our bodies from the environment. These include pesticides, hormone and antibiotic residues in meat and dairy products, food-borne bacteria; chemicals in cleaning products, food additives, cosmetics; the metabolic by-products of unfriendly gut bacteria, etc.
• xenobiotics can impair the activity of the liver and kidneys, thus decreasing conversion of T4 to T3.
• xenobiotics have been shown to increase the production of reverse T3 – a form of T3 in which the iodide group normally removed from T4 is left on and another iodide is removed instead. Since reverse T3 is shaped differently from normal T3, it does not produce the same effects.

• Autoimmune disease: in autoimmune disease, the body’s immune system develops antibodies that attack its own cells – in this case, the cells in the thyroid gland. Experts are not certain why the immune system starts to attack the thyroid:
• two current theories are:

1. a virus or bacterium with a protein resembling a thyroid protein triggers the immune attack.
   This theory is backed up to some extent by the association between hepatitis C, for instance, and the onset of autoimmune hypothyroidism.
2. a genetic defect or susceptibility leads to the development of abnormal thyroid cells that provoke an attack by T cells, important agents in the immune system.

• Hashimoto’s thyroiditis, a common form of hypothyroidism, is an autoimmune disease linked to genetic susceptibility. Named after the Japanese physician who first described the condition, it presents with a goiter, and results in damage to the thyroid gland, therefore requiring life-long treatment.
• atrophic thyroiditis is a variation on Hashimoto’s thyroiditis in which no goiter is present.

• postpartum thyroiditis: In 1 : 2,000 women, hypothyroidism may develop during or after pregnancy. These women develop antibodies to their own thyroid during pregnancy, causing a thyroid inflammation that typically develops 4–12 months after delivery. Fortunately, this type of hypothyroidism usually resolves on its own, although bouts of hyperthyroidism may also occur before thyroid function normalizes.
• Women who experience recurrent episodes of postpartum thyroiditis after multiple pregnancies, or who have other autoimmune disorders, may develop permanent hypothyroidism.
• Riedel’s thyroiditis is a rare disorder in which patients develop a hard stony mass that suggests cancer, but which responds well to thyroid replacement.

• Drugs: many drugs contain iodine or have properties that disrupt thyroid function, although the effectsare almost always reversible when the drugs are stopped:
  • lithium: widely used to treat psychiatric disorders, lithium has multiple effects on thyroid hormone synthesis and secretion. Up to 50% of patients who take lithium develop goiter, and another 20–30% develop subclinical hypothyroidism.
  • amiodarone (Cordarone): a drug used to treat abnormal heart rhythms that contains iodine and can induce hypothyroidism.
  • certain antidepressants may cause hypothyroidism.
  • epilepsy drugs, including phenytoin and carbamazepine, reduce thyroid hormone levels.

X-rays: ionizing radiation from medical and dental X-rays, particularly those received in childhood, can adversely affect thyroid function.

Radioactive iodine: high-dose radiation for cancers of the head or neck, or for Hodgkin’s disease causes hypothyroidism in up to 65% of patients within 10 years after treatment.

Frequent “yo-yo” dieting: the body reacts to any significant reduction in calories consumed by turning down the conversion of T4 to T3 – its metabolic thermostat.

Pituitary tumour (rare): a pituitary tumour will disrupt normal production of TSH, the hormone that stimulates the thyroid to produce T4.

RISK INCREASES WITH

• Sex and age: women are three to eight times more likely than men to develop hypothyroidism. Some experts estimate that as many as 10% of women over 50 have low thyroid function.
• Depression: a recent study indicates that the active form of thyroid hormone (T3) and L-tryptophan (a precursor of the neurotransmitter serotonin, a chemical important for feelings of well-being) are taken up by red blood cells using the same carrier. Alterations in one substance may affect the other.
• Radiation treatment for cancers of the head or neck, or Hodgkin’s disease.
• Frequent dieting
• Surgery for hyperthyroidism
• High intake of goitrogens (foods that impair the use of iodine).
• Use of prescription drugs including lithium, amiodarone, phenytoin, carbamazepine: so many drugs affect the thyroid that anyone taking drugs for the treatment of chronic disease should discuss the impact these on thyroid function with their physician.
• Disease-promoting diet: thyroid function is dependent upon adequate amounts of a number of vitamins and minerals. A diet based on processed foods, with little consumption of fresh vegetables, legumes, fruits, nuts and seeds, whole grains, and cold-water fish is low in the factors necessary for T4 production and conversion to T3 – vitamins A, B2, B3, B6, and C, and trace minerals zinc and selenium.
• Genetic susceptibility: about half of those whose close relatives have chronic autoimmune disease haveantibodies to the thyroid. Thyroid disease will often skip generations; someone with low thyroid functionmay have parents with normal thyroid activity, but grandparents who had thyroid problems:
• Turner’s syndrome: approximately half of those with Turner’s syndrome, one of the most common genetic diseases in women, have hypothyroidism, usually the autoimmune form called Hashimoto’s thyroiditis.
• Smoking, especially during pregnancy: pregnant women with subclinical hypothyroidism who smoke between one and two packs of cigarettes daily are at risk for even lower thyroid function as well as decreased action of TSH in areas outside the thyroid, such as the liver. These women may also develop significantly higher levels of total cholesterol and low density lipoprotein (LDL) (bad) cholesterol than non-smoking women with subclinical hypothyroidism.
• Autoimmune disease, especially during pregnancy: women with insulin-dependent diabetes (type I) or other autoimmune conditions have a 25% risk for hypothyroidism during pregnancy. A miscarriage during early pregnancy may indicate the presence of antithyroid antibodies, and the risk for autoimmune-induced hypothyroidism is significantly elevated during the subsequent year.
• Anorexia or bulimia: people with anorexia or bulimia are at risk for hypothyroidism; in these cases, however, reduced thyroid function may be an adaptation to malnutrition. Treatment of the eating disorder will likely result in normalization of thyroid function.
• Childhood X-ray treatments: Everyone who has had head and neck radiation should have their thyroid glands examined regularly. Between 1920 and 1960, 2 million Americans, mostly children, received X-ray treatments to the head or neck for acne, enlarged thymus gland, recurrent tonsillitis, or chronic ear infections. Their risk of developing thyroid nodules and thyroid cancers is increased, particularly in those who have developed hypothyroidism, and cancer can develop as long as 40 years after the original treatment.
• Atherosclerosis: hypothyroidism is associated with atherosclerosis (commonly known as hardening of the arteries) and heart disease. Individuals with hypothyroidism are at higher risk due to their typically high levels of LDL (bad) cholesterol, even in subclinical hypothyroidism, and elevated levels of the cholesterol-carrying molecule lipoprotein(a), or Lp(a). Treatment of hypothyroidism can significantly reduce total cholesterol, LDL, and Lp(a), helping to prevent hardening of the arteries.
• High blood pressure: hypothyroidism may also slow the heart rate to less than 60 bpm and reduce the heart’s pumping capacity. Although a recent study found no association between hypothyroidism and high blood pressure in older women, hypothyroidism does increase the risk for high blood pressure in pregnant women.
• Disease associations: hypothyroidism is associated with Addison’s disease, iron deficiency anemia, respiratory problems, myasthenia gravis, ovarian failure, sleep apnea, premature gray hair, left-handedness, insulin-dependent diabetes, rheumatoid arthritis, and glaucoma.

PREVENTIVE MEASURES

1. Avoid excessive consumption of goitrogens: Brassica family foods (turnips, cabbages, rutabagas, mustard greens, radishes, horseradishes), cassava root, soybeans, peanuts, pine nuts, and millet. When eating these foods, be certain they are well cooked as cooking usually inactivates goitrogens.
2. Minimize drug use and use natural alternatives whenever possible.
3. Avoid X-ray treatments unless medically necessary.
4. Replace mercury-containing dental amalgams: amalgam fillings should be removed by a biologically trained dentist and replaced with non-metal (composite) fillings.
5. Minimize exposure to xenobiotics. Eat whole organically grown foods, check your water supply and, if necessary, install water filters to ensure clean water.
6. Exercise regularly and get adequate (an average of 8 hours per night) sleep.
7. If chronic allergies or infections are present, work with a physician to develop a health-promotion program that heals these conditions.
8. If weight loss is needed, don’t diet. Work with a physician to develop an individualized version of the health-promoting diet described below that will enable weight loss without endangering health.
9. Ensure adequate intake of key nutrients needed for production of T4 and its conversion to T3 by:
10. consuming a nutrient-dense diet rich in whole, unprocessed, preferably organic foods, especially plant foods (fruits, vegetables, beans, seeds and  nuts, and whole grains) and cold water fish, and low in animal products and processed foods .
11. taking a high-potency multiple vitamin and mineral supplement including 400 mg of folic acid, 400 mg of vitamin B12, and 50–100 mg of vitamin B6. (Folic acid supplementation should always be accompanied by vitamin B12 supplementation to prevent folic acid from masking a vitamin B12 deficiency.) A daily multiple providing all of the known vitamins and minerals serves as a foundation upon which to build an individualized health-promotion program.

Expected outcomes

In mild cases, hypothyroidism may be curable in 2–3 months, once underlying causal factors have been identified and an appropriate dietary, supplement, and exercise protocol instituted. Even in more severe cases, improvement in symptoms should be seen within 2 -4 weeks.

TREATMENT

Diet

• Avoid goitrogens: Brassica family foods (turnips, cabbages, rutabagas, mustard greens, radishes, horseradishes), cassava root, soybeans, peanuts, pine nuts, and millet.
• After removing goitrogens from your diet, choose a balanced diet composed of whole, unprocessed, preferably organic foods, especially plant foods (fruits, vegetables, whole grains, beans, nuts [especially walnuts], and seeds), and cold-water fish.

Nutritional supplements

• Armour desiccated thyroid: complete with all the thyroid hormones, not just T4, supplements made from desiccated natural thyroid gland are preferred over synthetic hormones, which typically contain only isolated T4:
• using thyroid hormone replacement should be a last resort after attempting to restore normal function to the various components of the thyroid system. T4 and T3 replacement may suppress the patient’s own hypothalamic–pituitary–thyroid axis and/or desensitize T3 receptors to the body’s own T3, leading to dependency on thyroid hormone replacement.
• because of the serious potential consequences of taking too much thyroid hormone, these preparations are available only by prescription from a physician.

• Thyroid extracts sold in health food stores: while much weaker, since licensing authorities require that they be virtually free of T4, thyroid support formulas sold in health food stores still do contain minimal amounts of thyroid hormone and may provide adequate support for mild hypothyroidism. In addition, most health food store products contain the other key nutrients the body requires to manufacture T4 and convert it to T3, including iodine, zinc, and tyrosine.

• Iodine and tyrosine: T4 is made from iodine and the amino acid tyrosine. Iodine’s only function in the body is the synthesis of T4, but too much iodine can actually inhibit this synthesis. Average intake of  iodine in the US is estimated to be over 600 ?g q.d.:
• dosage: neither dietary levels nor supplementation of iodine should exceed 600 ?g q.d.

• Trace minerals: the trace minerals zinc and copper, and the vitamins A, B2 (riboflavin), B3 (niacin), B6
• (pyridoxine), and C are all needed for the production of T4. Of the three enzymes that convert T4 to T3, one is dependent on the trace mineral, selenium, while the activity of another is increased by vitamin A. Dosages per day (which should be found in any high-quality multiple):

• zinc: 15–45mg
• copper: 1–2mg
• selenium: 100–200 mg
• vitamin A (retinol): 5,000 IU (women of childbearing age should not exceed 2,500 IU q.d. if becoming pregnant is a possibility due to the risk of birth defects.
• B2 (riboflavin): 10–50mg
• B3 (niacin): 10–100mg
• B6 (pyridoxine): 25–100mg
• vitamin C: 1,000–2,000mg.

Physical medicine

• Ensure a full 8 hours sleep each night.
• Exercise daily for 30–60 min:
  • exercise stimulates thyroid gland secretion and increases tissue sensitivity to thyroid hormone.
  • exercise is essential for overweight hypothyroid individuals who are dieting. Dieting has consistently been shown to cause a decrease in metabolic rate as the body strives to conserve fuel. Exercise prevents this decline in metabolic rate in response to dieting.
  • both weight training (which builds muscle mass) and aerobic exercise (which improves the body’s use of oxygen) should be part of a regular exercise program.

ICIM Medics Approach

If you feel that this article relates to you then please make an appointment for Your Thyroid Function Assessment : http://icimmedics.com/medical-assessments/thyroid-function-assessment/

The results from the assessment can then be used by one of our Natural Medical Practitioners who will help you with your individualised treatment plan. This may include dietary, nutritional and/or botanical advice.

Should other underlying issues be suspected such as toxicity, then further more specific testing can be conducted http://icimmedics.com/medical-assessments/toxicity-assessment/

This article is not meant to be used for treatment but for information purposes only. If you feel that this approach is appropriate for you please contact ICIM Medics on 045 844 819 or www.icim.ie e-mail : info@icim.ie Both appointments can be arranged for you.

Tags: Endocrine Gland, Hypothyroidism, Thyroid