Thursday, March 8, 2012

When You Hear Hoof Beats....

In medicine, there is a popular saying that "when you hear hoof beats, think of horses not zebras."  It means that patients are much more likely to have a common illness as opposed to an esoteric one.

This saying came to mind yesterday when one of my patients, whom I will call John, handed me Dr. Mark Hyman's book Ultra-Metabolism. John's wife was previously diagnosed with Alzheimer's disease and hypothyroidism. John is a bright man and devoted spouse searching for solutions to his wife's problems.

John gave me the book because he wanted me to read a chapter in the book called Fortify Your Thyroid and give him my thoughts.

In the said chapter, after a short patient case history, Hyman starts with the following:

"Because doctors are trained to look for "real disease" (with "textbook" symptoms that can be diagnosed and matched to a prescription drug), subtler, chronic symptoms are often [bold added for emphasis] ignored.But those symptoms are the clues to the deeper mystery of what is wrong with you." 

He goes on to say that 20% of women and 10% of men have a sluggish thyroid and "half of them are undiagnosed. To make matters worse, many of those who are diagnosed are not treated properly." Yet, later on after panning the skills of doctors, he states "thyroid dysfunction is often a problem that requires additional testing and a doctor's assistance to overcome it."  He then goes on to identify gluten as one of the major culprits of thyroid disease. If that were the case, why not just stop gluten for a while (as he suggests) and meanwhile, do nothing else until you see what happens? That he doesn't say.

I read the entire chapter for thoroughness. John is expecting a report back from me about my thoughts, but here's a preview of them.

Dr. Hyman is a little bit absolutely right and mostly absolutely wrong. Why? The answer is because there may actually be circumstances when doctors misdiagnose subtle clinical symptoms. However, patients usually don't present with subtle clinical symptoms. If they are very subtle, they just don't come to the doctor. Yes, its true they may come for one illness and also have another. Yes, its also true that rushed for time, doctors may not always be as thorough, sensitive to, or on the look out for subtle symptoms. Yes, its even true that some doctors may be less than optimally competent. (The student who graduates last in his class in medical school is still called doctor.) However, when they hear hoof beats, doctors really should think of horses, not zebras.

To that end, let me share some historical information.  In the 1980s, doctors routinely ordered what are called Thyroid Function Tests (TFTs) for most patients. They are simple enough blood test that mostly revealed any thyroid dysfunction. Medical and other insurances basically put a stop to these routine tests because by and large they revealed no thyroid abnormality. The reason is because most people, as Dr. Hyman readily admits,  do not have thyroid disease.

Dr. Hyman has a checklist of items that one should use to determine if they need special tests to check for subtle thyroid disease. Here are several I think are fairly common.

1. Do you have elevated cholesterol?
2. Do you drink chlorinated or fluoridated water?
3. Do you have trouble losing weight, or have you recently experienced gaining weight?
4. Have you experienced a loss of sex drive?
5. Do you experience fatigue?
6. Do you experience depression and apathy or anxiety?
7. Do you experience constipation?
8. Do you have muscle fatigue pain or weakness?
(Here's my favorite:)
7. Are you currently or have you been exposed to environmental toxins?
(To answer this one no, you'd have to be a Martian.)

This is not an exhaustive list. According to Dr. Hyman, if you check off four you need all these extra fairly expensive blood tests to make sure what is really going on.

However, here's the statement that caused me the most problem as it creates paranoia and unnecessary discomfort for patients.

Hyman writes, "There is no one perfect way, no one symptom or test result, that will properly diagnoses low thyroid function or hypothyroidism. The key is to look at the whole picture-your symptoms and your blood tests--and then decide."  The statement is fear mongering at its worse.

First, unless you have symptoms suggestive of thyroid disease, it would be inappropriate for your doctor to order thyroid blood tests. (If doctor started ordering many additional tests for every patient for every subtle symptom, our health care system would implode from far worse over-utilization, and worse, patients would undergo many unnecessary tests that would lead to a plethora of false positive results, and consequently, superfluous, if not potentially painful, harmful, expensive, and anxiety provoking procedures and treatments, all for nothing.)

Second, if a doctor can't fully depend on these tests, why order them in the first place? According to Dr. Hyman, he wants even more tests ordered and then not to truly trust them as well unless the symptoms are there. There is a failed circular logic here.

The chapter goes on to pan doctors as not being caught up on medical treatment of thyroid disease and not knowing about the latest medication choices. It's amazing and sad that he feels it is appropriate to denigrate many fine doctors who treat patients every day and make his unsubstantiated assumptions about them.

Now here's the ultimate pain for me in everything he writes about the thyroid. Instead of using a FDA approved and well tolerated drug such as synthroid that has been used for decades, he suggests ArmourThyroid, a non-FDA approved substitute. He actually gives their website address, but fails to alert the reader that they are not FDA approved. It even took me a few minutes to figure it out because they present themselves as if they are a prescription drug by using menu headings like "Full Prescribing Information." Is Hyman seriously advocating that patients treat their own thyroid disease? That what it seems to me when you direct people to a website where they can order the product directly for their own use. I truly hope he has no financial interest in ArmourThyroid because I still like Mark Hyman, despite his penchant for the over-dramatization, and the Institute for Functional Medicine, which he leads, and finding out he is gaining financially from advocating for ArmourThyroid would be too much to bear.

So my final thought is Dr. Hyman is probably right sometimes (that some cases of thyroid disease are not properly identified and treated), but so is a monkey throwing darts at a stock list. There is no need to alarm patients and send them into a whirlwind by suggesting doctors can't diagnose and treat something he asserts is so common. So after reading but one chapter of one of his NY Times best-selling books, I think it is fair to say I won't be reading any more and nor should you.

As for John, he is coming to see me with his wife next week to discuss how to treat her previously diagnosed by another doctor hypothyroidism. I will repeat the basic thyroid blood tests to determine her current levels. I will not, however, chase zebras when I hear hoof beats.

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