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Life Extension Magazine

LE Magazine September 2004
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Thyroid Deficiency
Preventing a Metabolic Meltdown
By Raphael Kellman, MD

Fatigue, weight gain, insulin resistance, depression, and dementia are all associated with the degenerative aspects of aging. Yet many of these symptoms may actually be caused by hypothyroidism, which is often overlooked and misdiagnosed. A simple thyroid stimulating hormone (TSH) blood test can reveal your thyroid status and help you avoid misdiagnosis of these symptoms.

An estimated 5% of Americans suffer from hypothyroidism, a deficiency of the thyroid gland, and many go undiagnosed.1 Patients and their doctors often disregard common symptoms, mistaking them for “normal” signs of aging. In my integrative medical practice, I offer patients an alternative to suffering with symptoms that are eminently treatable.

A swollen and inflamed thyroid gland. The pituitary gland secretes thyroid stimulating hormone (TSH). TSH levels are monitored in patients with thyroid disease.

Role of the Thyroid
The thyroid is a small, butterfly-shaped organ in the neck, located above the collarbone and below the Adam’s apple. This tiny gland is vital to regulation of the body’s metabolism. Made up of small sacs, the thyroid is filled with an iodine-rich protein called thyroglobulin, along with the two thyroid hormones, T4 (tetraiodothyronine, or thyroxine) and T3 (triiodothyronine). T3, the more active of the two thyroid hormones, is produced in much smaller amounts than T4, which accounts for about 93% of the hormone produced. Most of the T3 is created by conversion from T4, which occurs in the liver and kidneys.

The primary function of these two hormones is to convert food into energy and to regulate the body’s other systems. A deficiency in the production (or absorption) of thyroid hormones can cause a global decline in the body’s metabolic reactions and lead to a host of symptoms, most commonly fatigue, weight gain, low body temperature, dry skin, and hair loss in the eyebrows.2-4 But low thyroid function—that is, hypothyroidism—can also produce more far-ranging symptoms, potentially affecting all of the body’s organs and cells. That is why I make it a point to test a patient’s thyroid levels whenever he or she presents with a common and often interrelated series of health problems.

The Testing Controversy
Diagnosing hypothyroidism has sparked an ongoing debate in the medical community over what hormone levels constitute a hormone deficiency. Generally, doctors use the TSH blood test to diagnose thyroid conditions. TSH is produced in the brain’s pituitary gland. A pituitary that produces excess TSH indicates that the thyroid is functioning below par and therefore requires more stimulation than normal. The problem lies in defining the standard range for TSH levels. I have found that even at the edges of the so-called “normal” range, many patients suffer from untreated hypothyroidism, with significantly diminished health.

The reference ranges published by various laboratories are subject to change as new information becomes available. In fact, the medical profession always adjusts these ranges to reflect new discoveries in clinical practice. For example, while a total cholesterol level of 300 mg/dL was once considered normal, we now know that that number is far too high, and levels around 200 mg/dL are now recommended.

In 2002, the American Academy of Clinical Endocrinology revised the normal range for TSH levels downward to the current values of 0.2-5.5 mµ/ml.5 From testing and treating patients who present with significant health problems, I and many other doctors believe that this upper value is still too high. Studies have shown that values of more than 4.0 mµ/ml increase the prevalence of heart disease after correcting for other known risk factors.6 Other research reveals that people with TSH values of more than 2.0 mµ/ml have a higher risk of developing overt hypothyroid disease over the next 20 years.7 Research also links hypothyroidism with high cholesterol. When the level of TSH is over 1.9 mµ/ml, with concomitant high levels of cholesterol, doctors should look for thyroid deficiency before treating the patient with cholesterol-lowering drugs.8 These findings all show a notable difference between the optimal TSH range and the so-called “normal” range.

Even when tests reveal “normal” TSH levels, I sometimes suspect the presence of hypothyroidism, especially in older patients, as thyroid deficiencies often imitate age-related symptoms. In such cases, I perform a stimulation test using thyrotropin-releasing hormone (TRH) to disclose low thyroid performance even if a blood test is normal. The TRH stimulation test is conducted only under the direct supervision of a physician. The test requires the intravenous injection of the hormone TRH with additional blood sampling before and after the injection. The results of this test help to distinguish between outright hypothyroidism and “subclinical” or developing hypothyroidism. In some individuals (and depending on the physician’s interpretation of the laboratory tests), outright hypothyroidism may take as long as 20 years to develop. With the help of measures such as the TRH stimulation test, I am able to diagnose hypothyroidism when the onset of symptoms (fatigue, weight gain, etc.) precedes abnormal laboratory values. Early intervention thus may save patients from years of needless suffering.

Symptoms of Hypothyroidism
I generally prefer to observe patients closely and assess their entire range of symptoms to determine whether hypothyroidism is a contributor to their condition, and then to use blood tests to confirm hypothyroidism. I first look for deficiency, low metabolism or tiredness, and weight gain, though there are many other indicators. According to the pioneering physician Broda Barnes, author of Hypothyroidism: The Unsuspected Illness, there are at least 47 symptoms of low thyroid function—most of them overlooked by blood tests. “The development and use of thyroid function blood tests,” Barnes wrote, “left many patients with clinical symptoms of hypothyroidism undiagnosed and untreated.” For this reason, Barnes estimates that up to 34% of the adult population has some form of thyroid deficiency.

In addition to fatigue, I have found that symptoms may include depression, dementia, decreased cognitive function (“brain fog”), a weakening of the immune system, constipation, weight gain and fluid retention, irregular menstrual cycle, infection, discoloration of the skin, hair loss, and drooping eyelids.9-17 A sluggish thyroid can also be linked to a fatty liver or high cholesterol, candida, and low glucose and insulin levels. In extreme cases, untreated hypothyroidism can cause anemia, low body temperature, and heart failure.18-27 Additional tests to better determine the significance of such symptoms include a liver panel, a complete blood count (CBC), a chemistry panel including a cholesterol profile, the candida antibody test, and a fasting insulin level.

Because the thyroid governs metabolic processes extending all the way down to the cellular level, every organ and system of the body can potentially be affected by its dysfunction. For example, hypothyroidism can affect the digestive tract, leading to constipation. This occurs when a sluggish metabolism affects the cells lining the gut walls, in turn slowing peristalsis, the contractions that govern bowel movements. Slowed metabolic activity in the brain can manifest as lowered mood and depression, the result of a decreased production of neurotransmitters. Nerve cells that are not firing well may produce decreased cognitive function. In fact, many elderly people with hypothyroidism have been misdiagnosed as suffering from dementia.

One of my patients, a 78-year-old woman who was progressively declining at home, had lost overall function, was tired and forgetful, and could not remember the names of those close to her. Routine tests for TSH showed her to be in the “normal” range, and her doctors had concluded that she was suffering from “beginning dementia,” an all-too-common misdiagnosis in the elderly. Suspecting hypothyroidism, I tested her and then started her on low doses of thyroid hormone, to which she immediately responded. Her memory returned and her overall function improved dramatically. “I feel like I was rescued from the dead,” she told me. Although many patients with subclinical hypothyroidism show no symptomatic improvement upon treatment according to the medical literature, it is impossible to refute this anecdotal observation. It is tragic that so many elderly patients are considered untreatable and dismissed as “over the hill” when their symptoms, due to hypothyroidism, can be alleviated with hormone treatment.

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