What is Hypothyroidism and How Is It Treated?
Richard Gracer, M.D.
Hypothyroidism is a common medical condition that affects many more women than men. Most hypothyroidism is a result of an inflammation of the thyroid called thyroiditis. This may be a result of a viral infection, or a type of "autoimmune" process during which the body actually fights itself. Another example of this type of disease is rheumatoid arthritis.
At times the symptoms are severe and obvious. Often however, they are vague and can be downright subtle. The classic symptoms of a low thyroid are fatigue and sluggishness, feeling cold, cold hands and feet, infertility, heavy menstrual periods, constipation, dry skin and hair, weight gain without increased appetite or increased calorie intake, swelling of the soft tissues, depression, and the early development of heart disease.
As early as 1892, animal thyroid extracts were used for treatment. There was some concern over variable potency, and in the 1960s synthetic thyroid hormone was developed. The synthetic thyroid hormone currently in use is pure thyroxine (T4), brand name Synthroid or Levoxyl. The thyroid produces both T4, which has 4 iodine atoms, as well as a much smaller amount of T3, which only has three iodine atoms. T3 is four times as potent as T4. The animal extracts contain both T4 and T3.
At first the dosages of the synthetic T4 were very high, often two to three times what we prescribe now. Many physicians in the past were content to allow their patients to have thyroxine levels on the high side, even if the TSH level was lower than normal, indicating that the thyroxine dose was too high. They watched for clinical signs of thyroid overdose and monitored the patient's well being. Because of concerns with abnormally increased and irregular heart rate, and possible reduced bone density (osteoporosis), the doses were decreased. In addition, more sensitive blood tests became available to measure TSH, a hormone from the brain that stimulates the thyroid to make thyroid hormone. TSH levels are high if there is not enough T4 in the blood in order to stimulate the thyroid to produce more. It is now generally believed that when the TSH level is normal, the body has enough thyroid hormone.
Most physicians are now content to have their patients "stabilized" on very precise doses of thyroxine, which normalize the TSH and T4 blood levels. Currently the recommended dose of thyroxine is 100 to 200 micrograms a day. Many patients, however, do not feel well on these dosages. They feel better with considerably higher doses than the blood tests indicate.
Psychiatrists have known for years that T3 helps treat depression in patients who seem to have normal thyroid function. T4 does not help. This has been well documented in many clinical studies and is commonly used to treat depressed patients. There has been speculation as to why this helps.
Research in rats as modern as 1996 in the journal Endocrinology, shows that giving T4 alone to rats with no thyroid does not increase the amount of T3 in the cells to normal levels.
In the February 11, 1999 issue of the New England Journal of Medicine, Bunevicius and his group studied the effects of giving T4 mixed with T3 versus T4 alone to hypothyroid patients. He found that most indicators of well being and mood were significantly better with T4 and T3 treatment as compared to T4 alone.
T4 is converted to T3 at cellular level by a specific enzyme. T4 is not actually used by the cells. T3 is the active hormone. It seems clear that the enzyme that changes T4 to T3 may be deficient, causing symptoms of hypothyroidism even in people who have normal T4 levels. These patients need to take T3.
Physicians who use animal thyroid extracts, such as Armour thyroid or natural thyroid are often considered to be on the " fringe" and "unscientific". I received a letter from and old friend and colleague who is a thyroid specialist. I had changed a mutual patient from the carefully regulated T4 that he had prescribed to a thyroid animal extract because she still had ongoing significant symptoms of depression that were resistant to therapy. I suspected that she needed more T3.
Although it is too early to tell if this particular women will respond, I've had innumerable patients with various mixtures of the symptoms listed above who have gotten much better on the animal extract type thyroid. I am delighted that carefully performed clinical studies in major medical journals are now showing what many nutritional physicians have known for many many years.
Natural thyroid is very inexpensive and works very well. There is a mixture of T3 and T4 on the market called Thyrolar. The ratios of T3 to T4 in Thyrolar are very close to that used in the New England Journal article mentioned above. I am considering using it in cases where the natural extracts are not working or have too much T3.
As an avid believer in the science of medicine, this is one of the instances where I must be comfortable with clinical experience and clinical response. I always test thyroid function and make sure that my patients have safe levels of T4 and T3. In addition, there are clinical signs of taking too much thyroid. These include a fast heart rate, extra heartbeats, nervousness, irritability, and weight loss. There are significant other clinical considerations to be taken before thyroid in any form should be prescribed.
If you feel that you have any of the symptoms of hypothyroidism see your physician. If you're being treated for low thyroid and still are symptomatic even though you have normal tests, you may want to try adding T3 to your medication under your doctor's supervision. If he of she is not comfortable with the natural thyroid preparations, ask about Thyrolar or Cytomel, a pure form of T3.
Book Recommendation: The Thyroid Solution, by Arem, is an excellent discussion of this problem with effective solutions.