The Unreliable TSH Lab Test by Jeffrey Dach MD
Suzy is a 59 year old post menopausal woman with low thyroid function. About three months ago, she started her bio-identical hormone program which included natural thyroid pills. After starting the program, she was doing well with more energy, better sleep, improved appearance of skin and hair, and resolution of her menopausal symptoms of flashes and sweats.
A New Set Of Thyroid Labs
However about 12 weeks into her program, Suzy had a visit with her primary care doctor who did a follow up thyroid panel. Her primary care doctor informed Suzy that her TSH test result was outside of the normal range, and therefore, her thyroid dose was too high, and should be reduced. (Note TSH stands for Thyroid Stimulating Hormone and is made by the pituitary gland)
Too Many Doctors Spoil the Soup
Suzy called me at the office distraught and confused. Two doctors were telling her two different things and she didn't know who to believe. Her primary care doctor was telling her one thing and I was telling her another.
A Low TSH Test is Unreliable For Adjusting Dosage
I explained to Suzy that her primary care doctor was incorrect in relying slavishly on the TSH test. Even though her TSH test was 0.15 which is below the lab reference range of .3, this was perfectly acceptable and indicated her thyroid medicine was suppressing the TSH to a low level which was perfectly fine.
No Clinical Evidence of Thyrotoxicosis
I also informed Suzy that her Primary Care Doctor is mistakenly relying on the TSH test to determine her thyroid dosage. The TSH test is an indirect measure of thyroid function and can be unreliable. A more accurate indicator of thyroid function is the free T3, which in her case was 375, well within the normal range of 240 to 420. The Free T3 lab test together with the absence of any signs or symptoms of thyroid excess indicates she is using the correct dosage of natural thyroid medication. Symptoms of thyroid excess are rapid heart beat or palpitations, and Suzy reported no such symptoms. In fact, Suzy said she felt fine and now that she understands it, she didn't want to go back to the way she was feeling before she started the thyroid pills.
This scenario is repeated about once a week at my office.
Conventional Docs Slavishly Rely on the TSH
Conventional primary care doctors use a different lab panel from mine. They never do a Free T3 test which is the most informative thyroid lab test, and instead rely on the TSH which is not a direct measure of thyroid function and can in fact be unreliable. Most conventional doctors are unfamiliar with the use of natural thyroid which contains both T3 and T4, and instead use Synthroid which is quite different, containing only T4.
No Time for Explanations
Since the Primary care doctors bill the health insurance for the office visit and payment is only a few dollars, the office visit is brief, 3-5 minutes. In this short time, Primary care doctors can provide only the most basic care, which is a quick look at the TSH lab test. If the TSH is below the lab reference range the doctor gives a new prescription for Synthroid with a with reduced dosage. If the TSH is above the reference range, the primary care doctor will increase the Synthroid dosage.
The Cleveland Clinic Chimes In
A few months ago, I found myself talking on the phone with an endocrinologist at the Cleveland Clinic explaining why the TSH blood test can be unreliable. He informed me I was wrong, and that he uses the TSH test as the gold standard. We agreed to disagree and parted company as friends. I have found that, in general, endocrinologists and mainstream doctors rely heavily on TSH to make a diagnosis of low thyroid.
Why Thyroid Blood Testing is Unreliable.
I recommend to you a book by Barry Durrant Peatfield, "Your Thyroid and How to Keep It Healthy". A general practitioner in the British National Health Service, Peatfield came to the US to train at the Broda Barnes Institute. He later returned to England and started his own thyroid clinic. His book contains the wisdom of 25 years of diagnosing and treating thyroid conditions. One section of the book is devoted to the question,
Why are thyroid blood tests unreliable?
Here is what Dr. Peatfield says:
1) Anxiety in the medical establishment about rules and dogma has led to a slavish reliance on blood tests, such as the TSH, which are often unreliable and can actually produce a false picture.
2) Very few doctors can accept the fact that a normal, or low TSH, may still occur with low thyroid function.
3) As a result of this test (TSH), thousands are denied treatment for low thyroid condition.
These same sentiments are shared by the teachings of Broda Barnes MD, in his classic book on Low Thyroid. Broda Barnes MD reported 40 years ago on the same problems with his medical colleagues relying too heavily on thyroid blood tests.
Hypothyroidism the Unsuspected Illness, by Broda Barnes MD, is a medical classic and should be required reading for every medical student and doctor. I have read the book many times. The book contains the condensed wisdom of a lifetime of research and clinical experience with the thyroid, and it rings true today as it did in 1976. Thyroid blood tests come and go, yet human physiology remains the same.
Hypothyroidism the Unsuspected Illness, by Broda Barnes MD
Broda Barnes estimated that up to 40% of the population suffers from a low thyroid condition and would benefit from thyroid medication. Of course, Barnes' opinion differed with that of mainstream medicine of his time which relied dogmatically on thyroid blood tests to make the diagnosis of low thyroid. Barnes felt the blood tests were unreliable and instead used the basal temperature, history and physical examination. This medical debate regarding unreliability of thyroid blood testing continues today.
Being an astute clinician, Dr. Barnes makes a number of observations about the low thyroid condition. Firstly, low thyroid is associated with a reduced immunity to infectious diseases such as TB. Before the advent of modern antibiotics in the 1940's, most low thyroid children succumbed to infectious diseases before reaching adulthood. Secondly, low thyroid is associated with a peculiar form of skin thickening called myxedema which causes a characteristic appearance of the face, puffiness around the eyes, fullness under the chin, loss of outer eyebrows, and hair thinning or hair loss.
A third observation by Dr. Barnes is that low thyroid is associated with menstrual irregularties, miscarriages and infertility. Barnes treated thousands of young women with thyroid which restored cycle regularity and fertility. In his day, the medical system resorted to the drastic measure of hysterectomy for uncontrolled menstrual bleeding. Although today's use of birth control pills to regulate the cycles is admittedly a far better alternative, Barnes found that the simple administration of desiccated thyroid served quite well. Again, Barnes noted that blood testing was usually normal in these cases which respond to thyroid medication.
A lengthy chapter is devoted to heart attacks and the low thyroid condition. Based on autopsy data from Graz Austria, Barnes concluded that low thyroid patients who previously would have succumbed to infectious diseases in childhood go on years later to develop heart disease. Barnes also found that thyroid treatment was protective in preventing heart attacks, based on his own clinical experience. Likewise for diabetes, Dr. Barnes found that adding thyroid medication was beneficial at preventing the onset of vascular disease in diabetics. Again, blood tests are usually normal.
Dr. Barnes devotes separate chapters in the book to discussion of chronic fatigue, migraine headaches and emotional/behavioral disorders all of which respond to treatment with thyroid medication.
The final chapter describes Dr. Barnes work on obesity when he resided over a hospital ward of volunteer obese patients, and monitored everything they ate. He found that the obese patients invariably ate a high carbohydrate diet, and avoided fat. Barnes added fat back into the menu and reduced the refined carbohydrates and found that his obese patients lost 10 pounds a month with no hunger pangs.
Missing from the book are discussions of Iodine supplementation and the role of the Adrenal, both of which are covered in later updated versions of Barnes thyroid book by other authors. See Hypothyroidism Type Two by Mark Starr, and Your Thyroid by Barry Durrant Peatfield. Iodine supplementation is covered by both Derry and Brownstein. The Safe Uses of Cortisol by William McK Jefferies is the companion medical classic devoted to the adrenals and cortisol.
Broda Barnes Institute
Although Broda Barnes has since passed away, his work lives in at the Broda Barnes Institute. Patricia Puglio is the director and a great resource. She is available by phone to answer questions and offer suggestions. Here is her contact information: Patricia A. Puglio, Director, Broda O. Barnes, M.D. Research Foundation, Inc. PO Box 110098 Trumbull, CT 06611 phone (203) 261-2101 patricia@brodabarnes.org www.brodabarnes.org
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http://jeffreydach.com/2008/10/12/hunt-study-shows-thyroid-prevents-heart-attacks-by-jeffrey-dach-md.aspxJeffrey Dach MD
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