Thyroid for Dummies (43 page)

ߜ Intolerance of cold

ߜ Constipation

ߜ Hardening of the arteries

ߜ Elevation of blood fats (especially ‘bad’ LDL-cholesterol) ߜ Weight gain

ߜ Elevation of blood pressure

ߜ Anaemia

ߜ Muscle cramps

ߜ Dry skin

ߜ Hair loss

All the above changes are common effects of ageing but are also signs and symptoms of hypothyroidism.

On the other hand, some signs found in older people tend to point away from a diagnosis of hypothyroidism, making an accurate diagnosis even less likely.

For example, older people get Parkinson’s disease, which results in tremors, or they simply develop senile tremors. Many elderly people lose weight because of poor nutrition; they may also develop anxiety and nervousness.

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hypothyroidism and may even point to an overactive thyroid gland, even though their thyroid is functioning below par. In addition, many elderly persons with hypothyroidism do not develop a goitre.

Getting laboratory confirmation

The only way to know for sure that an older person does not have hypothyroidism is to obtain thyroid function tests. If hypothyroidism is present, the free T4 is low and the TSH is high (refer to Chapter 4). Often the TSH is high but the free T4 is normal – the situation known as subclinical hypothyroidism.

The only way to determine whether hypothyroidism is having an effect upon the patient is to give a trial of thyroid hormone, although, the patient does not always feel much different on medication.

Trying thyroid hormone

for subclinical patients

Among older people with subclinical thyroid disease and a TSH level of less than 10, only half show some clinical improvement after receiving thyroxine (T4 hormone replacement). Such patients should probably not have treatment if they complain of angina heart pain. Most people whose TSH level is over 20 µU/ml (microunits per millilitre) tend to improve with treatment, however.

An important study, whose results indicate that subclinical hypothyroidism in older people is worth treating, was published in
Clinical Endocrinology
in 2000. In this study of 1,843 people aged 55 and over, those with an elevated TSH but a normal free T4 had a three times greater risk of developing dementia and Alzheimer’s disease than those with normal TSH and free T4 – even when followed for as short a time as just two years. Concluding that the lower the free T4 (though still in the normal range), the higher the incidence of dementia and Alzheimer’s. Those individuals with positive antiperoxidase antibodies (refer to Chapter 4) also had a higher incidence of dementia. This report is the first study to suggest that subclinical hypothyroidism in older people increases their risk of dementia and Alzheimer’s disease.

Another factor that influences treatment decisions is that an older patient who has subclinical hypothyroidism along with another autoimmune disorder – such as Type 1 diabetes, pernicious anaemia, rheumatoid arthritis, or premature greying of the hair – is likely to eventually develop clinical hypothyroidism.

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If you have subclinical thyroid disease and your doctor starts you on thyroid hormone replacement, there are several reasons why you may want to continue that treatment. If you test positive for thyroid autoantibodies and you have a high TSH, chances are very good that you’ll develop clinical hypothyroidism in the future. Also, your cholesterol level may benefit from the thyroid hormone; a measurement of cholesterol before and after taking the pills often shows that it is lowered significantly. Thyroid hormone also lowers a chemical in the blood called
homocysteine
, which if raised, is now known to contribute to heart disease.

Taking treatment slowly

As far as treatment is concerned, it’s important that the doctor goes slowly (which is, of course, against their usual nature). Treatment ideally starts with a very low dose of thyroxine (for example, 25 micrograms), increasing every four to six weeks until the TSH is at the upper limit of normal. You do not want excessive treatment as this increase sometimes worsens heart pain and increases shortness of breath, palpitations, and rapid heartbeats, as well as nervousness and heat intolerance. Even the first exposure to a small dose of thyroxine may bring on angina chest pain. A dose that is excessive can also lead to osteoporosis (brittle bones).

The major problem doctors have when treating older people with hypothyroidism is often compliance – ensuring that someone remembers to take his or her medication. Putting the pills into a case with daily slots may help.

Testing thyroid function on a regular basis to ensure that the TSH and free T4

levels remain normal is also important. Testing every six months is usually adequate.

Managing Hyperthyroidism

in Older People

Toni is the 76-year-old aunt of Stacy and Karen (refer to Chapter 5 for more on them). Her husband notices that she seems depressed lately. While she used to love cooking, she seems to have lost interest. She sits on her couch most of the day, not doing much of anything. She gains several pounds in weight and seems fatigued most of the time. Toni’s doctor suggests that perhaps she is hypothyroid. He obtains thyroid function tests and, to his 27_031727 ch20.qxp 9/6/06 10:45 PM Page 254

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surprise, the free T4 is elevated and the TSH is suppressed, suggesting a diagnosis of hyperthyroidism. He sends Toni to the local thyroid specialist clinic.

The clinic finds that Toni does not have a goitre. However, her pulse is somewhat fast. The doctor makes a diagnosis of apathetic hyperthyroidism and explains to Toni’s husband that this type of hyperthyroidism is not uncommon in older people. He starts Toni on the antithyroid drug, carbimazole.

After six weeks, Toni’s thyroid function tests are normal. The carbimazole is stopped and Toni is given radioactive iodine several days later.

Toni is feeling so much better that she invites the entire family to a delicious buffet in a lovely dining room recently remodelled by Toni’s husband, where they all chat about their various thyroid problems.

Sorting through confusing

signs and symptoms

Hyperthyroidism is less common than hypothyroidism, but it’s still a significant problem among the elderly. As with hypothyroidism, the symptoms of an overactive thyroid are easily confused with the normal signs of ageing.

The following characteristics are among the similarities between normal ageing and hyperthyroidism, and the person often experiences: ߜ Shaking

ߜ Weight loss

ߜ Irregular heart rhythm

ߜ Increased threat of congestive heart failure

ߜ Intolerance to heat

ߜ Profuse sweating

ߜ Fatigue and weakness

At the same time, older people may develop signs that aren’t consistent with hyperthyroidism at all. They may appear entirely apathetic, sitting very quietly, acting depressed, and showing fatigue and weight gain. This combination is the picture of apathetic hyperthyroidism that Toni experiences. In addition, many older patients with hyperthyroidism don’t have a goitre.

Sometimes, the only sign of hyperthyroidism is the finding of
atrial fibrillation
, a rapid and irregular heartbeat. (If you’re diagnosed with atrial fibrillation, you usually need to take an anticoagulant to prevent blood clots forming in the 27_031727 ch20.qxp 9/6/06 10:45 PM Page 255

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irregularly beating heart. After the heart rhythm is restored to normal, the anticoagulant is stopped.)

If your heart rhythm suddenly becomes very irregular, and your doctor tells you that it’s atrial fibrillation, ask your doctor to remember to check your thyroid function tests.

Loss of bone is another important consequence of hyperthyroidism. Older people, particularly women whose bones are naturally thinner, cannot afford to lose more bone. One study, published in the
Journal of Clinical Investigation
in 2000, shows that older people with hyperthyroidism have significant reduction in bone density when compared to a similar group of people without hyperthyroidism. After people with hyperthyroidism are successfully treated, however, their bone mineral density improves within six months. Other studies show a definite increase in bone fracture risk in people with hyperthyroidism.

Securing a diagnosis

Thyroid function tests remain the key method for diagnosing hyperthyroidism in older people. If hyperthyroidism is present, the free T4 is high and the TSH is suppressed. Occasionally, the T4 is normal but the free T3 is elevated, a condition called
T3 thyrotoxicosis
(check out Chapter 6). This condition is especially common if a hyperactive nodule is the source of the hyperthyroidism.

The treatment of choice for hyperthyroidism in the elderly is radioactive iodine (RAI). With a single treatment, the disease is brought under control in four to six weeks. RAI avoids the problems associated with taking daily antithyroid pills. However, many people who take RAI develop hypothyroidism and then need a daily thyroid hormone pill for the rest of their lives.

A beta-blocker such as propranolol is also useful in controlling symptoms of hyperthyroidism (such as tremor, nervousness, sweating, and rapid heart rate).

If RAI is given to treat a hyperactive thyroid, there is occasionally a sudden release of thyroid hormones as the thyroid tissues break down. In an older person, this reaction can lead to a sudden worsening of heart failure and a very rapid heart rate, as well as chest pain. To avoid this complication, antithyroid drugs are given for six weeks before the RAI is given. When someone has normal thyroid function on the drugs, the risk of a sudden release of thyroid hormones is eliminated.

Most heart symptoms associated with hyperthyroidism disappear after treatment is successful. However, sometimes the atrial fibrillation does not reverse and may need continued treatment.

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Checking Out Thyroid Nodules

in Older People

Nodules are common in later life, but thyroid cancer is found less often in older than in younger people. The nodules are studied with a radioactive iodine scan to see whether or not they are active, and an ultrasound to see whether they are filled with fluid (cystic). Both of these characteristics point to a benign nodule rather than a cancer. Thyroid function tests can show whether the nodule is overactive and needs treatment.

In the final analysis, a fine needle aspiration biopsy is the best single test to rule out cancer in a nodule. If this test is positive for cancer, surgery is the treatment of choice, with follow-up similar to that for anyone with thyroid cancer (refer to Chapter 8).

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Part V

The Part of Tens

"Your bizarre eating disorder is due to a

thyroid problem but that's no excuse for

eating my receptionist, Mr. Weblott."

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In this part . . .

As you would expect, a part of your body as impor-

tant as the thyroid prompts all sorts of myths and

mistaken ideas. Here you find the ones we consider the most important (and possibly the most damaging if you believe them). The final chapter shows you what you can do to make sure that you maximize your thyroid health in ten easy steps.

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Chapter 21

Ten Myths about Thyroid Health

In This Chapter

ᮣ Getting the facts about weight loss and gain

ᮣ Learning the truth about hormone replacement

ᮣ Understanding how thyroid disease occurs

ᮣ Trusting your symptoms

Thanks to the Internet, you have access to incredible amounts of information about your thyroid. Unfortunately, a lot of the material is inaccurate, and importantly, you need to maintain a healthy degree of scepticism. This chapter aims to clear up some commonly held myths concerning the thyroid and its diseases.

I’m Hypothyroid, So I Can’t Lose Weight

If you have hypothyroidism, or if you receive treatment for a thyroid condition and the cure results in an underactive thyroid, you may find you have a hard time losing weight. The myth is that you can’t lose weight if you have hypothyroidism, even when it’s properly treated. The truth is that a large percentage of people who are successfully treated for hypothyroidism weigh almost the same after treatment as they did before they developed the disease. And some people with hypothyroidism – mostly older people – actually lose weight, rather than gain it, after receiving replacement thyroid hormone. This loss occurs when a person is receiving poor nutrition, which is made worse with the general lack of interest that can accompany hypothyroidism, so the person is simply not interested in eating properly and consumes too few calories.