Researchers found that defects in the hypothalamus-pituitary-adrenal axis have been observed in autoimmune diseases (such as thyroid disease), rheumatic diseases, chronic inflammatory disease, chronic fatigue syndrome and fibromyalgia. They also found that levels of thyroid hormone are decreased during severe inflammatory disease.
What Causes CFS, FMS and HAIT?
Until definitive research is completed on CFS, FMS, HAIT and other autoimmune diseases, there are many hypotheses as to the causes behind these diseases. Some FMS researchers are looking at abnormally low levels of the hormone cortisol and its relationship to FMS. Other FMS researchers are studying regulation of the adrenal gland (which makes cortisol) in fibromyalgia.
Some medical researchers believe that a virus (such as Epstein-Barr, the mononucleosis virus is at the core of these diseases. And while no single virus or cause has been firmly associated with CFS, FMS or HAIT, one medical journal reported that 78% of the CFS patients studied in one research effort also tested positive for the Epstein-Barr Virus. Anecdotally, many thyroid patients report having had serious bouts of mononucleosis, or recurrent Epstein-Barr virus, prior to being diagnosed with HAIT.
Other researchers believe bacterial infection, stress, an accident (such as an auto accident) or other trauma may chronically activate the immune system. The immune system, which ordinarily returns to normal after successfully fighting an infection, then remains in a hyperactive state.
Others have suggested the development of one autoimmune disorder, such as rheumatoid arthritis or lupus may then precipitate the onset of CFS, FMS or HAIT.
And certain researchers are looking to autoimmune thyroid disease itself as perhaps the underlying cause of some CFS and FMS symptoms, or perhaps the root cause of the diseases themselves.
Is Thyroid Function and Hormone Conversion At the Center of the Mystery?
Dr. John C. Lowe, one of the nation's pioneers in fibromylagia research, has, in a 1997 research study reported in the Clinical Bulletin of Myofascial Therapy, that he found clear relationships between thyroid function and fibromyalgia, and believes that some form of hypometabolism, including thyroid dysfunction, may in part explain FMS.
In studying patients with diagnosed fibromyalgia, Dr. Lowe ran thyroid function tests on each patient. Those with elevated TSH levels (indicating hypothyroidism) did not undergo TRH stimulation tests. Those who had normal TSH levels were subsequently also given a TRH stimulation test.
Of the patients studied:
- 10.5% had primary hypothyroidism.
- 36.8% were diagnosed as euthyroid (in normal thyroid state)
- 52.6% had results, via the TRH test, that were consistent with central hypothyroidism.
Dr. Lowe cites unpublished studies which indicated that while euthyroid fibromyalgia patients do not have a thyroid hormone deficiency, they benefit as much from receiving T3 as most hypothyroid fibromyalgia patients do from T4. T3 is one of the two thyroid hormones, known commercially as Cytomel, and also a component in the T4/T3 drugs levothyroxine sodium (Synthroid and others), Thyrolar, and the naturally derived Armour Thyroid. Dr. Lowe indicates that a reason for this could be partial cellular resistance to thyroid hormone, as euthyroid fibromyalgia patients resemble patients with thyroid hormone resistance syndromes.
Some HAIT patients who do not resolve their hypothyroidism symptoms while taking T4-only drugs (and having normal levels on TSH tests) have found that taking the T4/T3 combination drugs relieve their hypothyroidism symptoms. This suggests some sort of underlying thyroid hormone resistance syndrome or FMS may also be at play in HAIT patients who do not thrive on the conventional T4 therapies.
Similar linkages between CFS and thyroid hormones have also been suggested. In a 1993 article published in the journal Medical Hypotheses researchers indicated that "...we believe much of the symptomatology [of chronic fatigue syndrome] can be explained by...disturbances of insulin and T3-thyroid hormone functions."
In an article by Raphael Kellman, M.D. in the magazine Alternative Medicine Dr. Kellman indicates that hypothyroidism -- an underactive thyroid -- as well as certain nutritional deficiencies, may underlie many cases of chronic fatigue.
