Thyroid for Dummies (44 page)

Keep in mind that hypothyroidism is associated with fatigue. Many people with hypothyroidism reduce their physical activity as a result and may not restore their previous level of activity after the hypothyroidism is treated properly.

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If you struggle to lose any weight you’ve gained due to hypothyroidism, and if your activity level remains the same, it’s possible that your thyroid treatment is inadequate (which is determined with a TSH test) or possibly that you need to take T3 replacement hormone in addition to T4 although this treatment is controversial (refer to Chapter 5).

You may also have another autoimmune condition present. Because the most common cause of hypothyroidism is autoimmune thyroiditis (refer to Chapter 5), ask your doctor to check you for diabetes mellitus Type 1 or autoimmune adrenal insufficiency (Addison’s disease – failure to make the hormone cortisol), among other conditions. This check is easily done with a blood glucose test for diabetes or a serum cortisol level for autoimmune adrenal insufficiency.

The bottom line is that if you take in more energy (calories) than you need, you gain weight. If you take in too little energy, you lose weight. Another truth is that your metabolic rate declines, as does your tendency to move around, as you age. Both changes tend to make weight loss more difficult, but it’s still possible.

If you have hypothyroidism and are on the proper dose of thyroid hormone, you can lose weight with sufficient diet and activity. So, try to eat less and exercise more. You may find that cutting back on your intake of refined carbohydrates (white bread, pasta, rice) and eating more wholegrain versions (brown bread, rice, and pasta) is helpful.

I’m Hyperthyroid, So I Can’t Gain Weight

The myth that hyperthyroidism always causes weight loss is a source of confusion in making an accurate diagnosis. Although the majority of people do lose weight when they are hyperthyroid, some actually gain weight –

especially the elderly.

A study published in the
Journal of the American Geriatric Society
in 1996, compared 19 classical signs of hyperthyroidism between older and younger patients. They found that three signs occur in more than 50 per cent of older people: rapid heartbeat, fatigue, and weight loss. However, some have no weight loss or even experience weight gain. Only two signs – loss of appetite and an irregular heart rhythm – happen more often in the older patients.

Overall, of the 19 classical clinical signs, older people show only six of them on average, while younger people have 11.

Other studies show similar results and emphasise the importance of checking levels of thyroid hormones and TSH in older people before making a diagnosis of hyperthyroidism.

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Weight loss, as well as other symptoms of hyperthyroidism, is not always present. One solution is to get thyroid blood tests every five years, beginning at age 35, but costs of screening make this move controversial.

Breastfeeding and Antithyroid

Pills Don’t Mix

For years, doctors advised women taking antithyroid pills for hyperthyroidism during pregnancy not to breastfeed. This advice was in case medication entering the baby’s circulation through the breast milk made the baby hypothyroid.

This notion is now firmly in the realms of myth. Two important studies show this belief is incorrect. In one study published in the
Journal of Clinical
Endocrinology and Metabolism
, 88 mothers took an antithyroid drug (methima-zole, a drug similar to carbimazole that is in use in America) for 12 months.

Close follow-up showed that all the babies of treated mothers had normal thyroid function. They grew normally, and had identical IQ, verbal, and functional tests to children who breast-fed from mothers without hyperthyroidism.

In a second study, breastfeeding mothers took another major antithyroid drug, propylthiouracil (PTU). Again the babies’ had normal thyroid function tests and perfect development.

A hyperthyroid mother taking antithyroid drugs to control her hyperthyroidism may safely breastfeed her new baby.

Brand Name Thyroid Hormone

Pills Are Best

The number of people taking thyroid replacement hormone throughout the world is enormous, and the amount of money spent on thyroid hormone replacement pills is also huge. The company that captures the largest share of the market makes its shareholders very happy.

A myth has arisen that cheaper, generic preparations of thyroxine (T4 hormone) are not equal in potency to brand name thyroxine. This myth began, as so many do, with research that was correct at the time but is now out-dated. In a study published in the
Journal of the American Medical Association
in 1997, 20 women with hypothyroidism took four different preparations of T4, at the same dosage, for six weeks at a time, one after the other. Blood 29_031727 ch21.qxp 9/6/06 10:46 PM Page 262

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tests taken during this study show absolutely no difference in any of the preparations and all had equivalent activity. The preparations, including two brand names and two generics, are sufficiently equal in their activity that there is no reason to choose any one over the others. In the United Kingdom, most doctors prescribe generically, and most pharmacists dispense generically to help save the NHS money. You may find you get several different versions of T4 during your time on treatment, depending on which is available at the cheapest price. Generic thyroid preparations save the NHS money and are used interchangeably with brand name thyroxine.

I Have to Take Thyroid

Medication for Life

Many patients believe that once they’re on thyroid hormone replacement, they’ll take it for life. For many people, this belief is true. Any treatment that removes or destroys much of the thyroid (such as surgery or radioactive iodine) does require treatment with thyroxine (T4 hormone) for life. However, in certain situations, hypothyroidism is temporary; you may need thyroxine for a time, but can later stop taking it. Sometimes, the fact that you no longer need the medication is obvious, but other times you and your doctor may decide to attempt a trial period off thyroid hormone for four to six weeks to see if you still need it.

The following are some of the conditions that require thyroid hormone replacement for a limited amount of time. Each is explained in detail in Chapter 11:

ߜ
Subacute thyroiditis
causes the temporary breakdown of thyroid cells and the release of thyroxine from the thyroid. As this condition improves, thyroxine is made and stored again, and oral thyroxine is no longer necessary.

ߜ
Silent and postpartum thyroiditis
also cause temporary loss of thyroxine, which is restored with time.

ߜ
Acute thyroiditis
occasionally requires temporary treatment with thyroid hormone.

The major diagnosis that means you may or may not need to take thyroid hormone pills for life is chronic thyroiditis (also known as Hashimoto’s or autoimmune thyroiditis – check out Chapter 5 for more on this condition).

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levels of blocking antibodies fall. The only way to know if this fall happens is to measure antibody levels or to stop the thyroid hormone and test thyroid function four to six weeks later. If your thyroid function remains normal, you may not need to take thyroxine any longer.

Depending on your diagnosis, you can sometimes stop taking thyroid hormone treatment at some point. It’s well worth checking, particularly if you are less than 40 years of age.

Natural Thyroid Hormones Are Better

Than Synthetic Hormones

The first thyroid hormones used to treat people with low thyroid function came from the thyroids of animals – a preparation called
desiccated thyroid
(refer to Chapter 5). After decades of use, desiccated thyroid is now replaced with synthetic thyroid hormones made in the laboratory. Some holdouts still believe desiccated thyroid is superior to synthetic thyroxine (T4 hormone) for treating hypothyroidism. As long ago as 1978, an article in the
American
Journal of Medicine
asked ‘Why does anyone still use desiccated thyroid?’

The article declared desiccated thyroid an obsolete therapy.

Hormones extracted from animals have plenty of problems: ߜ Desiccated thyroid does not provide a standard amount from dose to dose because one animal has a different amount of hormones in its thyroid than the next animal.

ߜ Not only does the dose of T4 and T3 in desiccated thyroid vary from pill to pill, but it does not provide the same levels as a normal thyroid releases.

ߜ Desiccated thyroid contains animal impurities that can cause immune reactions.

ߜ The use of desiccated thyroid confuses thyroid testing. If only the total T4 hormone is measured, that result is often low due to the large amount of T3 in the medication. The patient may receive even more thyroid hormone and actually become hyperthyroid.

The only thing going for desiccated thyroid is that it does contain some T3, which most synthetic hormone replacements do not. However, synthetic T3

does now exist, and is far superior to the mixture in desiccated thyroid.

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Synthetic thyroxine is currently the medication of choice in the treatment of hypothyroidism. Some thyroid specialists believe that, in the future, treatment may advance to involve a combination of T4 and T3 in the exact ratio that it leaves the thyroid.

Thyroid Disease Is Catching

Understanding why this myth is so entrenched in the minds of the public isn’t hard to do. Most thyroid disease is inherited; so the likelihood of finding the same disease in two sisters or a mother and her daughter is relatively high, suggesting that their physical closeness to one another causes one to catch the disease from the other. Furthermore, in areas where people don’t consume enough iodine, practically everyone has thyroid disease – again suggesting that it’s infectious.

Another situation that seems to suggest that thyroid disease is catching is the occurrence of thyroid disease after large-scale radiation exposure. Just about everyone comes down with some illness in that situation. Children, especially, often develop goitres, nodules, and thyroid cancers.

An understanding of the way these diseases develop, quickly clarifies the situation:

ߜ Hereditary thyroid diseases affect the females of a family, usually spar-ing the males.

ߜ After iodine is supplied, the incidence of thyroid disease rapidly declines in iodine-deficient areas.

ߜ Children who take iodine pills or avoid exposure to radioactive iodine generally do not get thyroid diseases, while those who do not, will.

ߜ You cannot catch thyroid disease, nor can you give it to someone else in the way that germs are passed from person to person.

Iodine Deficiency Is a Medical Problem

Because iodine deficiency (refer to Chapter 12) causes hypothyroidism, goitre, and cretinism (when severe), the belief that the disease responds to medical treatment with iodine seems clear-cut. If so, however, the disease would have disappeared years ago.

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As with any major medical problem (like AIDS, breast cancer, and prostate cancer), iodine deficiency is a social, economic, and political problem as much as, or more than, it is a medical problem.

To begin with, an understanding about the cause of hypothyroidism in iodine-deficient areas is often lacking. The people are poor, work very hard, and have little time for the intricacies of the cause of disease. Their poverty means they cannot afford to pay for nurses to give them medication or inject them with iodised oil. They do not understand that certain foods, like cassava (a starchy tuberous root used to make flour), worsen the problem, so they continue to consume large quantities of them.

Often the local or national government pumps in lots of money to improve the situation and provides iodine supplementation, but provides no punish-ment for those who do not follow the regulations. Manufacturers may fail to put any iodine into their so-called ‘iodised’ salt and claim the subsidies for it anyway. Much of that money disappears after it leaves government control.

Sometimes, attempts to solve the problem run up against the realities of salt production – as is the case in Indonesia, for example, where salt is in the hands of numerous salt farmers rather than a centralised salt production facility (as in China). As a result, altering salt production to make enough iodised salt in China than in Indonesia is easier and more productive.

When there’s a tremendous need for a substance like iodine, the cheats try to profit from people’s misery. They charge more for iodised salt and then fail to actually iodise the salt. They also under price the government’s iodised salt so that people buy their salt rather than true iodised salt from the government.

The instability of poor governments also plays a role. In Communist East Germany, iodine provision brought the disease under fairly good control.

After the reunification of East and West Germany, however, the combined government neglected the problem and iodine deficiency started to reappear.

The solution to a clearly medical problem like iodine deficiency often involves social, cultural, and economic changes that populations resist, making a cure exceedingly difficult.

The Higher My Autoantibody Levels,

the Worse My Thyroid Disease

This myth derives from a phenomenon that seems obvious: The more you have of something that denotes a disease, the worse that disease usually is.