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Hypothyroidism
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Contents
Thyroid Basics
Causes of Hypothyroidism
Risk of Hypothyroidism
Associated Disease
Symptoms of Low Thyroid
Diagnosis: Standard Laboratory Test
New Diagnostic Reference Standard for TSH
Free T3 and Free T4
New Laboratory Reference of Hypothyroidism
Treatment
What to do if you are already on Synthroid
Summary
More than 10 million Americans have been diagnosed with
thyroid disease, and another 13 million people are estimated to have undiagnosed
thyroid problems. About 10 percent of the
adult population is afflicted with this frequently overlooked disease of epidemic
proportion. A dysfunctional thyroid can affect almost every aspect
of health. It
is one of the most under-diagnosed hormonal imbalances of aging, together with
estrogen dominance and syndrome X.
Thyroid Basics
Thyroid
is a small butterfly-shaped gland that wraps around the windpipe. The cells
inside the thyroid takes in the iodine, obtained through food, iodized salt,
or supplements, and combines that iodine with the amino acid tyrosine. The thyroid
then converts this into the hormones thyroid hormones called T3 and T4.
Once released by the thyroid, the T3 and T4 travel through the bloodstream.
Under normal conditions, 80 percent of thyroid
hormones are in the form of and T4 and 20 percent in the form of T3. T3 is the
biologically more active and is several times stronger than T4. The
conversion of T4 to T3 takes place both inside the thyroid as well as in some
organs other than the thyroid, including the hypothalamus, a part of your brain.
The thyroid gland acts like the body's barometer. Its main function is to help
cells convert oxygen and calories into energy. It regulates:
· Heart rate
· Blood pressure
· Body temperature
· Metabolism
· Growth
Thyroid, like other hormones, is regulated by an extensive negative feedback
system. The system starts in the hypothalamus of the brain that releases Thyrotropin-releasing
Hormone (TRH). TRH signals the pituitary gland to release Thyroid Stimulating
Hormone (TSH). TSH in turn instructs the thyroid gland to make thyroid
hormones and release them into the bloodstream. When the level of thyroid hormone
in your body is high, a negative feedback system exists to reduce the production
of TSH, and vice-versa. Therefore, a high
TSH is indicative of hypothyroidism, while a low TSH can be indicative of hyperthyroidism.
Causes
of Hypothyroidism
There are a variety of factors that can contribute to the development of thyroid
problems:
· Exposure to external radiation such as occurred after the Chernobyl nuclear
plant accident.
· Over-consumption of isoflavone-intensive soy products such as soy protein
or powder. Isoflavones act as potent anti-thyroid agents, and are capable of
suppressing thyroid function, and causing or worsening hypothyroidism.
· Some anti-thyroid drugs, such as lithium and the heart drug cordarone.
· History of radiation treatment to the head and neck area.
· Over-consumption of uncooked "goitrogenic" foods, such as broccoli,
turnips, radish, cauliflower, and Brussels sprouts.
· Radioactive iodine treatment for hyperthyroidism/Graves' Disease.
· Post-surgical removal of all or part of the thyroid due to nodules or cancer.
· Adrenal insufficiency (commonly caused by chronic stress).
· Mercury intoxication (amalgams are 50% mercury). Amalgam fillings have been
associated with a variety of problems such as Alzheimer's disease, infertility,
neurotransmitter imbalances, and thyroid problems.
Risk
of Hypothyroidism
You have a higher risk of developing thyroid disease if, among a variety of
factors,
…You have a family history of thyroid problem
…You have a history of Chronic Fatigue Syndrome
…You are a female and over menopausal
…You are over age 60
…You have been exposed to radiation or certain chemicals (i.e., perchlorate,
fluoride)
Associated
Disease
As many as 10 percent of 98 million Americans with high cholesterol and high LDL ("bad") cholesterol may not know that their cholesterol is high due to undiagnosed thyroid problem. Older women with sub clinical or under-active hypothyroidism was shown to be twice as likely as women without this condition to have heart attacks.
Thyroid disease is also intricately tied to adrenal
gland and ovarian function.
Symptoms
of Low Thyroid
Being one of the master regulators of body metabolism, symptoms of low thyroid
function generate a global response. Symptoms include:
· Fatigue and low energy, with need for daytime nap.
· Depressed, down, or sad.
· Skin that becomes dry, scaly, rough, and cold.
· Hair becomes coarse, brittle, and grow slow.
· Excessive unexplained hair loss.
· Sensitivity to cold in a room when others are warm.
· Difficulty in sweating despite hot weather.
· Constipation that is resistant to magnesium supplementation.
· Difficulty in loosing weight.
· Unexplained weight gain.
· High cholesterol resistant to cholesterol lowering drugs.
Diagnosis:
Standard Laboratory Test
A popular way of diagnosing hypothyroidism is using basal
body temperature. Dr. Broda Barnes, M.D, popularized this test. While
using basal body temperature can be better than using the standard thyroid function
test, it comes with certain disadvantages, including:
· Falsely elevated temperature when sleeping under eclectic blanket
· Poor compliance
· Accurate thermometer required
Most clinicians rely on blood test instead. The
traditional laboratory tests used to diagnose hypothyroidism are:
· Total T4
· T3 Uptake and
· Free Thyroxin Index (FTI)
· TSH (Thyroid Stimulating Hormone)
Due to the complexity and inherent weakness of the traditional laboratory tests,
there is widespread difficulty in their interpretation.
The key test is TSH. The lower
the amount of thyroid hormone in the body, the more TSH will be produced and
secreted by the pituitary to stimulate the thyroid gland to put out thyroid
hormones. A low TSH signals enough TSH on
board, while a high TSH signals a deficiency of TSH in the body.
For most traditional laboratories, the upper
limits of normal TSH level is under 4.0 to 4.5. While those who have
TSH higher than 4.5 is highly likely to have hypothyroidism, many more with
TSH under 4.5 have sub-clinical hypothyroidism or under-active thyroid.
The clinician easily misses these cases if the focus on diagnosis is based on
the traditional reference range only. Many with a TSH under 4.0 are in fact
symptomatic and may well be hypothyroid. In other words, the
traditions normal range is far too insensitive to detect hypothyroidism,
especially those in the sub-clinical stage of the disease with symptoms.
The myth that an elevated TSH level
(the upper limits of normal range by normal laboratory reference range is under
4.5) is required, as prerequisite for diagnosis of hypothyroidism must be dispelled.
There is little doubt that an elevated TSH signifies and under active
thyroid as the pituitary gland secretes TSH in response to a low thyroid hormone
level. The real question is - how high a TSH is considered high?
New
Diagnostic Reference Standard for TSH
There are doctors who believe that you do
not need to have an elevated TSH level (higher than 4.5) in order to actually
be diagnosed and treated for hypothyroidism. Increasingly, innovative
doctors are also viewing high-normal or normal TSH levels (by traditional standards)
as possible evidence of low-level hypothyroidism, especially if symptoms of
hypothyroidism are present.
The traditional normal laboratory range is relative. Many, especially women,
have symptoms -- or are hypothyroid -- when TSH is anywhere but at the lower
end of the normal range or 2 or thereabouts.
Many patients with TSH level of 2.0 (not 4.5)
or more have classic symptoms and signs of hypothyroidism. Even though
their TSH is considered "normal" by traditional standards, many are
suffering from under active thyroid or sub-clinical hypothyroidism. If your
routine blood work comes back with a TSH of 2.0 and you have symptoms of hypothyroidism,
ask your doctor! Chances are your thyroid gland is not working properly.
TSH alone, however, is not an accurate test of all forms of hypothyroidism
but only primary hypothyroidism. Addition tests like Free T3 (FT3) and Free
T4 (FT4) are required. Some doctors also test for elevated thyroid antibodies
in addition to FT3 and FT4. Many patients, especially women with elevated
antibodies are in the process of developing autoimmune thyroid disease. Early
detection is important to effect appropriate treatment. Even with normal TSH
levels, the majority of symptomatic women with elevated antibodies, low FT3
and low FT4 require thyroid hormone replacement to feel well.
Free
T3 and Free T4
Thyroid gland produces four thyroid hormones called T1, T2, T3, and T4. The
number indicates the number of iodine molecules attached to the molecule. T
4 is what synthetic thyroid such as Synthroid has. T4 is a hormone precursor
and is converted into T3, the form that performs most of the thyroid function
in the body. Thinking that synthetic thyroid proves steady hormone levels,
it is widely prescribed by doctors. Easily overlooked is the fact that many
people cannot convert the T4 to T3. This is easily confirmed by measure free
hormone level, a practice most doctors are not trained on.
Free T3 and Free T4 are the only accurate
measurement of the actual active thyroid hormone levels in the body. This is
the hormone that is actually free and exerting effect on the cells. These are
the thyroid hormones that count.
It is common to find Free T3 and Free T4 below normal when TSH could in the
normal range or in the low end of the normal range. This is indicative of secondary
or tertiary hypothyroidism. This is normally thought of as due to hypothalamus
or pituitary dysfunction, resulting in the body's inability to convert T4 to
T3.
New
Laboratory Reference of Hypothyroidism
1. If your FT4 is less than 0.7 (normal 0.7
to 2.0).
2. If FT3 is less than 2.3 (normal 2.3 to 4.2).
3. If your TSH is above 2.0
Ask for these tests. If your thyroid test results come back and your doctor
is not sure what it means, consider going to a reputable holistic physician
or alternative physician for further interpretation and diagnosis.
Treatment
The traditional standard treatment for hypothyroidism for decades is synthetic
T4 hormone levothyroxine, such as levoxyl and Synthroid.
Alternative physicians prefer Amour
Thyroid that contain natural thyroid hormones. Natural hormones also
have T1 and T2 in addition to T3 and T4. Armour thyroid is a natural desiccated
thyroid. It was the only available treatment for hypothyroidism for some
50 years. Because of concern about their variable potency, these extracts have
been considered obsolete for some time by all but a few natural prescribers.
Armour thyroid needs to be taken twice a day to provide the adequate and consistent
blood level of T3, which is shorter than that of T4. The common starting dose
is 90 mg cut in half and taken one half after dinner and the other half after
breakfast. Repeat blood test should be performed after one month and dosage
adjusted accordingly to maintain TSH under 0.5. Free T3 and Free T4 should be
maintained above the median but below the upper end of the laboratory normal
reference range.
Optimum FT3 and FT4 anti-aging range for healthy young adults is towards
the top end of normal range, while for the elderly is towards the middle of
normal range. Once TSH, free T3 and free T4 targets are reached, annual checkup
is warranted. Overweight and thyroid resistant patients might need to have
their dosage increased.
While synthetic thyroid hormone made in the laboratory by drug companies usually
contain T3 (Cytomel) and T4 (levothyroxine) or combinations (Thyrolar) of these
two. Patients with hypothyroidism show greater
improvements in mood and brain function if they receive treatment Armour thyroid
rather than Synthroid (thyroxin). Research reported in the New England
Journal of Medicine in February of 1999 found that a majority of patients, however,
might feel better on a combination of hormones such as combination of T3 and
T4 instead of single T4 alone.
Those
that do not wish to take thyroid replacement may consider non-commercially harvested
seaweeds as the best source of organically bound iodine. 5 grams a day is needed,
or about 1 ounce per week. A pound would last about two months. If
you cannot get good seaweed, consider kelp supplement as alternative.
What
to do if you are already on Synthroid?
If you are on Synthroid (T4), chances are your Free T4 is at or above the high
end of normal range and your Free T3 is below. You may wish to add 5 - 12.5
mg Cytomel (pure T3) after breakfast and after dinner rather than Armour thyroid
or Thyrolar (synthetic T4/T3 combination).
Hypothyroidism is one of the most under-diagnosed diseases of the aging process. Traditional laboratory tests are outdated and highly insensitive. Proper diagnosis of thyroid disease requires a careful history and physical examination, accompanied by laboratory studies such as TSH, Free T3 and Free T4. The use of newer and more sensitive laboratory ranges is critical in the proper interpretation of these test. Most patients requiring treatment will do well on natural thyroid replacement
The thyroid, adrenal, and ovarian axis requires intricate balance all the time. Factors that upset this balance, including female hormonal imbalance, excess intake of estrogen-like compounds such as soy, and adrenal stress can cause hypothyroidism.
Treatment of thyroid diseases must take into consideration the other the hormonal systems, including rebalancing of female hormones with estrogen and progesterone, and modulation of adrenal function with natural hormones such as pregnenolone and DHEA.
About The Author
Michael Lam, M.D., M.P.H., A.B.A.A.M. is a specialist in Preventive and Anti-Aging Medicine. He is currently the Director of Medical Education at the Academy of Anti-Aging Research, U.S.A. He received his Bachelor of Science degree from Oregon State University, and his Doctor of Medicine degree from Loma Linda University School of Medicine, California. He also holds a Masters of Public Health degree and is Board Certification in Anti-aging Medicine by the American Board of Anti-Aging Medicine. Dr. Lam pioneered the formulation of the three clinical phases of aging as well as the concept of diagnosis and treatment of sub-clinical age related degenerative diseases to deter the aging process. Dr. Lam has been published extensively in this field. He is the author of The Five Proven Secrets to Longevity (available on-line). He also serves as editor of the Journal of Anti-Aging Research.
For More Information
For the latest anti-aging related health issues, visit Dr. Lam
at www.DrLam.com. Feel free to email
Dr. Lam at dr@lammd.com if you have any questions.
Reprint Information
This article may, in its unabridged, unaltered form and in its entirety only,
be reprinted and republished without permission provided that it is for personal
and non commercial education use only and further provided that credit be given
to the author, with copyright notice and www.DrLam.com
clearly displayed as source. Written permission from Dr. Lam is required
for all other use.
© 2001 Michael Lam, M.D. All Rights Reserved.
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