Autoimmune Disorders

The thyroid gland is extremely important to our overall health and vitality. It is responsible for synthesizing thyroid hormones, including triiodothyronine (T3) and thyroxine (T4). Thyroid hormones impact the activity of nearly all cells in the body. These hormones are important for regulating metabolic rate, which means it affects how cells use and store energy. In addition, thyroid hormones play an important role in body temperature, protein metabolism, muscle strength, skin moisture levels, menstrual cycles, weight, cholesterol levels, brain development, breathing, heart rate and nervous system functions.

Levels of T3 and T4 are controlled in part by thyroid-stimulating hormone (TSH), which is released by the pituitary gland, which is, in turn, regulated by thyrotropin-releasing hormone (TRH) released from the hypothalamus. Levels of T4 in the blood are sensed by the hypothalamus-pituitary axis, and when levels are sufficient, TSH secretion generally is suppressed under healthy circumstances. When blood levels of T4 are low, the pituitary produces and secretes extra TSH to stimulate the thyroid to synthesize additional T4. Iodine is also required to synthesize thyroid hormones, and deficiency or excess of iodine can affect thyroid hormone levels. Thus, the regulation of thyroid activity is highly complex. Disorders resulting in over or under production of thyroid hormones are quite common and affect approximately 5 percent of women and 0.5 percent of men.¹ In addition, autoimmune thyroid disorders are the most common organ-specific autoimmune disorders and are estimated to occur in 2-5 percent of individuals in Western countries.²

Hashimoto’s Thyroiditis

Hashimoto’s thyroiditis is the name of the autoimmune thyroid disease that affects approximately 14 million Americans³ and is the most common thyroid disease in the United States. In Hashimoto’s disease, the body makes antibodies that attack the thyroid gland, resulting in decreased levels of thyroid hormone production (hypothyroidism). Lymphocytes, which are a type of white blood cell that can make antibodies, accumulate in the thyroid gland. Subclinical Hashimoto’s disease may not cause overt symptoms or the disease may progress and present with symptoms of hypothyroidism. These symptoms may include one or more of the following: fatigue, weight gain, cold intolerance, constipation, dry or thinning hair, dry skin, puffy face, depression, joint or muscle pain, decreased heart rate, irregular menstrual periods, infertility, increased cholesterol and fullness in the throat if a goiter is present. Hashimoto’s disease is 7 times more common in women than men and generally presents between 40 and 60 years of age.⁴

Although the exact cause of Hashimoto’s is unknown, research indicates that both genetic and environmental factors such as iodine intake, stress, medications and infections may be involved.^2,5 Individuals with other autoimmune diseases such as type 1 diabetes, vitiligo, Addison’s disease, systemic lupus erythematosus, celiac disease and rheumatoid arthritis are at increased risk of developing Hashimoto’s thyroiditis.⁶ Additionally, environmental exposures may play a role.⁷ Hashimoto’s disease is diagnosed by measuring levels of thyroid hormones and anti-thyroid antibodies in the blood. These tests may include TSH, T3, T4, and anti-thyroid peroxidase (TPO) antibodies.

Grave’s Disease

Grave’s disease is another autoimmune disorder affecting the thyroid, but unlike Hashimoto’s disease, this disorder results in increased thyroid function (hyperthyroidism). Grave’s disease is the most common cause of hyperthyroidism in the United States and is estimated to affect 10 million Americans or 2-3 percent of the population. This condition is 5-10 times more common in women than men, and generally presents during middle age.⁸ In Grave’s disease, the antibodies made by the body, known as thyroid-stimulating immunoglobulin (TSI), bind to the TSH receptor and mimic TSH released from the pituitary, resulting in increased thyroid hormone production. Grave’s disease often presents with symptoms associated with hyperthyroidism, such as fatigue or muscle weakness, anxiety, irritability, weight loss, heat intolerance, hand tremors, rapid and irregular heartbeat, difficulty sleeping, increased perspiration, brittle hair, menstrual irregularity, frequent bowel movements and possibly a goiter.

In addition, Graves’s disease may present with exophthalmos, which is protrusion of the eye out of the orbit and is caused by increased connective tissue deposition behind the eye. Grave’s ophthalmology can cause symptoms including red or inflamed eyes, light sensitivity and swelling of the eyelids and tissue around the eyes. In more severe cases, it may cause reduced or blurred vision, double vision, decreased eye movements and ulcers on the cornea.⁹ Similarly to Hashimoto’s disease, the exact cause of Grave’s disease is unknown; however, it is believed that genetic and environmental factors are involved. The risk of developing Grave’s disease in increased in those with other autoimmune diseases or a family history of the disease. Increased risk is also associated with smoking, stress and pregnancy.¹⁰ Grave’s disease is diagnosed by measuring TSH, T3, T4, anti-TPO antibodies, and occasionally anti-TSH receptor antibodies. Frequently, radioactive iodine uptake is measured, which evaluates the thyroid gland’s uptake of iodine.

Natural Support for Optimal Thyroid Function

L-Carnitine

Several dietary nutrients have been shown to benefit thyroid autoimmune disorders. L-carnitine is an amino acid derivative important in energy metabolism. Reduced levels of carnitine have been demonstrated in the skeletal muscle of both hyperthyroid and hypothyroid subjects, which may play a role in muscle weakness commonly seen with these conditions. Additionally, studies indicate that muscle carnitine levels return to normal when thyroid function in the hypothyroid and hyperthyroid subjects is normalized.¹¹ Another study examined carnitine excretion in the urine in both hyperthyroid and hypothyroid subjects. Compared to healthy control subjects, the hyperthyroid patients showed increased carnitine excretion. When the thyroid function was treated, carnitine excretion normalized.¹²

One study suggests that L-carnitine inhibits T3 entry into the cell nucleus, where T3 modulates DNA transcription.¹³ One randomized, double-blind, placebo-controlled trial investigated the effect of supplementation with 2 or 4 grams per day of L-carnitine in subjects with hyperthyroidism. The study showed that L-carnitine supplementation reversed or minimized the symptoms of hyperthyroidism in these subjects. Additionally, it was reported that L-carnitine supplementation was useful during thyroid storm, which is a severe manifestation of hyperthyroidism. Furthermore, researchers point out that hyperthyroidism depletes carnitine tissue stores, indicating supplementation may be beneficial in these conditions.^14-15

Iodine (Iodoral®)

Both clinical experience and research support the use of inorganic, non-radioactive iodine (Iodoral) in autoimmune thyroid disorders.¹⁶ The National Health and Nutrition Examination Surveys (NHANES) indicate that between NHANES I (1971-1974) and NHANES III (1988-1994), the median urinary iodine concentration decreased by 50 percent and low excretion of iodine (less than 5 mcg/dL) increased 4.5 fold.¹⁷ However, autoimmune disease has been increasing during the same time period that iodine intake has been decreasing in the U.S.¹⁸

In one study, individuals with Hashimoto’s thyroiditis and healthy controls were supplemented with iodide. The subjects with Hashimoto’s disease received one of five treatments: 1) a non-suppressive hormone medication; 2) a suppressive hormone; 3) a combination of a non-suppressive hormone plus low dose iodide (50-150 micrograms/day); 4) 200 micrograms per day of iodide or 5) no treatment. The healthy controls received either 200 micrograms iodide daily, weekly doses of 1.53 milligrams iodide or no medication. The results showed that in the group with Hashimoto’s thyroiditis, iodide supplementation significantly decreased levels of anti-thyroglobulin antibodies.

The researchers stated, “To lower the incidence of autoimmune thyroid diseases in predisposed subjects, a daily iodine supplementation seems to be superior to high-dose weekly administrations. A hormone therapy combined with a daily, low-dose iodine medication is able to reduce the anti-thyroglobulin antibodies and the anti-peroxidase antibodies levels even in patients with Hashimoto’s thyroiditis.”¹⁹

Iodoral® is a tablet containing 5 mg iodine and 7.5 mg iodide as the potassium salt and is considered by many physicians as well as the noted iodine researcher Guy Abraham, MD to be a superior form of iodine supplementation. To prevent gastric irritation, the iodine/iodide preparation is absorbed into a colloidal silica excipient; and to eliminate the unpleasant taste of iodine, the tablets are coated with a thin film of pharmaceutical glaze.

Prior to supplementation, iodine levels can be determined by taking the Iodine Sufficiency Test in order to establish an appropriate dosing regimen.

For those actively working to optimize the health of their thyroid, routine testing of thyroid status plus serum iodine and iodide levels, and monthly consultations with their health care provider is essential.

ATP Cofactors

Cellular energy (ATP) production requires the cofactors NADH and FADH2. These cofactors are derived from the B vitamins riboflavin and niacin (found in the supplement ATP Cofactors). In addition, these cofactors are required for generation of intracellular hydrogen peroxide, which is the rate-limiting step in the conversion of iodide to iodine by iodo-peroxidases, including thyroid peroxidase (TPO). This conversion is the first step in the synthesis of thyroid hormones.²⁰ One small study evaluated the effect of nicotinic acid (niacin) supplementation in subjects with elevated lipids on levels of thyroid hormones and thyroid binding globulin, the protein that transports thyroid hormones in the blood. This study found that supplementation with nicotinic acid over 1.3 years significantly decreased levels of total T4, T3 and thyroid-binding globulin, without inducing symptoms of hypothyroidism.²¹ This suggests it may be useful in the management of hyperthyroid disorders.

Conclusion

Autoimmune thyroid disorders are common causes for both hypo- and hyperthyroidism in the United States. Various natural therapies including iodine/iodide in the form of Iodoral along with riboflavin, niacin, and L-carnitine have been shown to modulate several relevant factors such as autoimmune antibody levels, thyroid hormone levels and the severity of clinical symptoms.

Next month, in the second part to this article, I will discuss other important autoimmune disorders and how to enhance the health of people who suffer from these conditions.

References

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2. Sgarbi JA, Maciel RM. Pathogenesis of autoimmune thyroid diseases. Arq Bras Endocrinol Metabol. 2009 Feb;53(1):5-14.

3. American Association of Clinical Endocrinologists. Hashimoto’s Thyroiditis. Available at: http://www.aace.com/pub/thyroidbrochures/pdfs/Hashimoto.pdf. Accessed on: 4-10-10.

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7. de Freitas CU, Grimaldi Campos RA, Rodrigues Silva MA, et al. Can living in the surroundings of a petrochemical complex be a risk factor for autoimmune thyroid disease? Environ Res. 2010 Jan;110(1):112-7.

8. Grave’s Disease Foundation. Understanding Grave’s Disease. Available at: http://www.ngdf.org/whatis_graves_disease.php. Accessed on: 4-10-10.

9. The National Endocrine and Metabolic Diseases Information Service. Grave’s Disease. Available at: http://endocrine.niddk.nih.gov/pubs/graves/. Accessed on: 4-4-10.

10. Mayo Clinic. Grave’s Disease. Available at: http://www.mayoclinic.com/health/graves-disease/DS00181/METHOD=print. Accessed on: 4-11-10.

11. Sinclair C, Gilchrist JM, Hennessey JV, et al. Muscle carnitine in hypo- and hyperthyroidism. Muscle Nerve. 2005 Sep;32(3):357-9.

12. Maebashi M, Kawamura N, Sato M, et al. Urinary excretion of carnitine in patients with hyperthyroidism and hypothyroidism: augmentation by thyroid hormone. Metabolism. 1977 Apr;26(4):351-6.

13. Benvenga S, Lakshmanan M, Trimarchi F. Carnitine is a naturally occurring inhibitor of thyroid hormone nuclear uptake. Thyroid. 2000 Dec;10(12):1043-50.

14. Benvenga S, Amato A, Calvani M, et al. Effects of carnitine on thyroid hormone action. Ann N Y Acad Sci. 2004 Nov;1033:158-67.

15. Benvenga S, Ruggeri RM, Russo A, et al. Usefulness of L-carnitine, a naturally occurring peripheral antagonist of thyroid hormone action, in iatrogenic hyperthyroidism: a randomized, double-blind, placebo-controlled clinical trial. J Clin Endocrinol Metab. 2001 Aug;86(8):3579-94.

16. Abraham GE. Facts about Iodine and Autoimmune Thyroiditis. The Original Internist. 2008 Jun; 15(2): 75-6.

17. Hollowell JG, Staehling NW, Hannon WH, et al. Iodine nutrition in the United States. Trends and public health implications: iodine excretion data from National Health and Nutrition Examination Surveys I and III (1971-1974 and 1988-1994). J Clin Endocrinol Metab. 1998 Oct;83(10):3401-8.

18. Abraham GE, Flechas JD, and Hakala JC. Orthoiodosupplementation: Iodine sufficiency of the whole human body. The Original Internist. 2002; 9:30-41.

19. Rink T, Schroth HJ, Holle LH, et al. Effect of iodine and thyroid hormones in the induction and therapy of Hashimoto’s thyroiditis. Nuklearmedizin. 1999;38(5):144-9.

20. Abraham GE, Flechas JD. The effect of daily ingestion on 100mg iodine in a tablet form of Lugol solution (Iodoral®) combined with high doses of vitamins B-2 and B3 (ATP Cofactors) on various clinical and laboratory parameters in 5 subjects with Fibromyalgia. The Original Internist. 2008 Mar; 15(1):8-15.

21. Shakir KM, Kroll S, Aprill BS, et al. Nicotinic acid decreases serum thyroid hormone levels while maintaining a euthyroid state. Mayo Clin Proc. 1995 Jun;70(6):556-8.