Hypothyroid  is  also  known  as  low or underactive thyroid. This condition occurs when the gland fails to produce proper amounts of the thyroid hormones (T3 and T4) to meet the body’s needs. Thyroid disease is estimated to affect 200 million people worldwide. Of those affected with thyroid dysfunction the majority are women, of which an estimated 50% remain undiagnosed.

There are numerous factors that may contribute to low thyroid function including:

• Autoimmune disease (known as Hashimoto’s thyroiditis)
  • Hyperthyroid treatment (using radioactive iodine or thyroid suppressing medications)
  • Thyroid surgery
  • Radiation therapy of the head and neck regions
  • Medications such as birth control, hormone replacement, and antidepressants
  • Pregnancy
  • Iodine deficiency
  • Pituitary tumor
  • Congenital defects

In addition to the many contributing factors for hypothyroid, the list of potential symptoms is also numerous.

Conventional testing for hypothyroid involves a blood test that primarily investigates TSH (thyroid stimulating hormone). If this measurement is elevated (>5.5 mlU/L), then a diagnosis of hypothyroid is given and patients are usually placed on thyroid medication; this shuts down the stimulation of the hypothalamus/pituitary, decreases your TSH, and “normalizes” your blood test (see Figure 1). While this can be helpful for some individuals, two main issues are left unaddressed. The first is that the laboratory values for appropriate thyroid level are based on a bell curve of diseased individuals, and not what a healthy optimum level should be. Second, the blood test does not investigate potential roots of the problem concerning hypothyroidism.

Six Patterns of Hypothyroid to Consider

Pituitary dysfunction – caused by chronic stress during which high levels of cortisol1 are secreted, pregnancy, low blood sugar or insulin resistance. These stressors tax the pituitary so it no longer signals the thyroid to release  hormone. With this pattern, individuals will experience hypothyroid symptoms but have a normal to low normal TSH (1.8-3.0 mlU/L). Underconversion of T4 to T3 – T4 (thyroxine) is the inactive form of the hormone and it must be converted  to T3 (triiodothyronine) before it can be used in the body. Common reasons for underconversion are inflammationandhighcortisol levels. Inflammatory chemicals (cytokines) damage the cell membranes and impair the conversion of T4 to T3.2 Elevated cortisol also  suppresses the conversion of T4 to T3.3 This results in hypothyroid symptoms but normal values of TSH, T4 and a low T3 reading (if tested).

Elevated TBG – TBG (thyroid binding globulin) is the protein transporter for thyroid hormone. When thyroid hormone is bound to TBG, it is inactive and unavailable to the tissues. Elevated TBG can be caused by high estrogen levels (from estrogen-containing birth control pills, or hormone replacement therapy). Thus, with high TBG, levels of unbound thyroid hormone will be low, leading to hypothyroid symptoms.⁴ With this pattern, TSH and T4 will be normal. T3 if tested will be low and TBG will be high.

Decreased TBG – the reverse of above. When TBG levels are low, free thyroid levels are high. Intuitively you would think this would cause high thyroid function, but  with  high thyroid levels circulating, the tissues develop a resistance, causing hypothyroid symptoms instead. Decreased  TBG  can  be   caused  by high testosterone levels, often associated with PCOS (polycystic ovarian syndrome) in women.⁵ This pattern reveals normal TSH and T4 and high T3.

Thyroid resistance – in this pattern both the thyroid and pituitary are functioning, but the hormones are not getting into the cells where they are needed. Possible mechanisms that block uptake of hormone include high cortisol from chronic  stress,  as well as high homocysteine which is a marker for inflammation.^6,7 Note, all lab markers in this pattern will likely be normal as there is no measure for cellular resistance.

Hashimoto’s thyroiditis – an autoimmune disease where the immune system develops antibodies that then attack thyroid tissue. Potential causes include: genetic predisposition, infections, toxins, nutrient deficiencies, food allergies (gluten) and medications. Here the TSH will be high, but can also swing too low. General recommendations for treatment is to keep the TSH under 3.0 mlU/L for stabilization of symptoms.

Subclinical Hypothyroid

This means that with respect to laboratory testing, your values are within range. However, your clinical history and physical symptoms  may all point to hypothyroid; therefore a course of thyroid treatment should still be considered.

Basal Body Temperature

Patients with suspected hypothyroidism that have normal lab values may get additional information about their condition by measuring basal body temperature. This test is performed by placing a thermometer deep in the armpit for 10 minutes, immediately upon waking and before getting out of bed. Typically the temperatures are taken over five days  and the results are averaged. Women should begin taking their temperature on the second day of menstruation, which is the time in the cycle when the body temperature is the lowest. If the temperature averages below 96.8° F, then this could be a clue that a hypothyroid condition is possible. Basal body temperature is an estimate of basal metabolic rate, which is intimately linked to thyroid function.

Treatment Options

Conventional treatment for hypothyroid is almost unanimously levothyroxine (synthroid). Additional options are triiodothyronine and dessicated thyroid compounds. While these medications may be clinically effective and relieve symptoms, there are also some natural compounds worth considering.

Tyrosine: An amino acid that when combined with iodine, makes thyroid hormone. It is interesting to note that tyrosine is also the building block for the stress hormones epinephrine and norepinephrine. Thus, when under stress, thyroid production can be reduced, as tryrosine is utilized for  the production of stress hormones instead.

Iodine: Numerous studies have shown  that  normal  thyroid   status   is dependent on the  presence  of  many trace elements for both the synthesis and metabolism of thyroid hormones. Iodine is most  important  as a component of the hormones thyroxine and 3,3’,5-triiodothyronine (T3), and iodine deficiency can be a key factor in hypothyroidism.

Coleus Forskohlii: The Ayurvedic herb Coleus forskohlii, and its active
constituent forskolin, can raise the production and release of thyroid hormones in animal and in-vitro studies.⁸

Bacopa monnieri: Studies in male mice showed that Bacopa possesses benefical thyroid-stimulating effects, increasing T4 concentration by 41% after supplementation for 15 days when compared to non-treated mice.⁹

Copper: Copper plays an important role in thyroid metabolism, especially in hormone production and absorption. Copper   stimulates   the   production of the thyroxine hormone (T4), and prevents over-absorption of T4 in the blood cells by controlling calcium levels in the body.

Zinc: Zinc plays an  essential  role  in thyroid hormone function. In fact, without the presence of zinc, the thyroid gland cannot transform the inactive hormone T4 into the active hormone T3. Furthermore, the  hypothalamus also requires zinc to make the hormone it uses to signal the pituitary gland to activate the thyroid. All of this means that people with insufficient zinc levels are likely to have an underactive thyroid gland.

Selenium:   Is   essential   for  normal thyroid hormone metabolism, it is a cofactor  for various iodothyronine deiodinases  (enzymes) the control the synthesis and degradation of the biologically active thyroid hormone, T3.¹⁰  Thyroid health is a key ingredient to managing   energy,   weight,   aging, and overall well-being. Low thyroid function can be something that may fly under the radar of regular medical checkups, or may be tested and deemed fine by laboratory standards.  This  article  has  attempted to highlight that this screening is not always sufficient, and your physical and emotional symptoms should be taken into account with equal consideration as there may be other factors at play.

REFERENCE

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2. Corssmit E et al. J Clin Endocrinol Metab. Acute effects of interferon-alpha administration on thyroid hormone metabolism in healthy men. 1995;80(11):3140-4.

3. Ann N et al. Acad Sci. Neuroendocrinology and pathophysiology of the stress system.1995; 771(29):1-18.

4. Ben-Rafael Z et al. Fertil Steril. Changes in thyroid function tests and sex hormone binding globulin associated with treatment by gonadotropin. 1987;48(2):318-20.

5. Bisschop P et al. Eur J Endocrinol. The effects of sex-steroid administration on the pituitary-thyroid axis in transsexuals. 2006;155(1):11-6.

6. Williams G et al. Lancet. Thyroid hormone receptor expression in the “sick euthyroid” syndrome. 1989: 23-30;2(8678-8679):1477-81.

7. Limpach A et al. Exp Cell Res. Homocysteine inhibits retinoic acid synthesis: a mechanism for homocysteine-induced congenital defects. 2000:10;260(1):166-74.

8. Ammon H et al. “Forskolin: From an Ayurvedic Remedy to a Modern Agent,” Planta Med Dec.6. 1985: 473-7.

9. Kar A et al. Relative efficacy of three medicinal plant extracts in the alteration of thyroid hormone concentrations in male mice. J Ethnopharmacol. 2002;81(2):281-5.

10. Arthur J et al. Thyroid function. Br Med Bull. 1999;55(3):658-68.

11. Chanoine J. Selenium and thyroid function in infants, children and adolescents. Biofactors. 2003;19(3-4):137-43. Review.

Additional Sources

www.thyroid.ca/thyroid_disease.php www.milwaukeethyroid.com/images/thyroid_diagram_large.jpg www.milwaukeethyroid.com/patterns.html www.thyroid.about.com/cs/testsforthyroid/a/labs2003.htm www.thyroid.org/what-is-hypothyroidism

12. Dong, B. How medications affect thyroid function. West J Med. 2000 February; 172(2): 102–106. Gaby, A.R., MD. Nutritional Medicine. 2011. P. 28-39.