Doug's Sounding Board

This information is taken from the book Thyroid Balance by Glenn S Rothfeld, M.A., M.Ac. & Deborah S. Romaine. The book presents the information in a form easy for most people to pick up. Why then am I writing this summary? The book is written so you can go to the chapter you think applies to you and get a fairly complete picture on what you need to know. This means a lot of information is repeated in each chapter and it makes finding specific information in the book more difficult when you want to go back and reference it. Also some of the repeated information is presented in a slightly different manner in different chapters which adds more information that just reading from one chapter.

What is the thyroid?
The thyroid is a gland that sits across the front of your throat and releases hormones to control your metabolism. The hormones that the thyroid produces also impact almost every function in your body. When it gets out of balance a number of health challenges can arise and since it is part of the endocrine system it needs to be in balance with all the other hormone producers in the body as well.

Who suffers from thyroid imbalance?
It’s estimated that 40% of all adults have some thyroid imbalance. Before the age of 50, 10% of women have a thyroid imbalance. After the age of 60 that rises up to 20%, and 10% of all men. Of those with a thyroid imbalance 90% have an underactive thyroid (hypothyroidism), and generally those with an overactive thyroid (hyperthyroidism) end up having an underactive thyroid. 1/3 to 1/2 of sufferers can have the sub-clinical form where your thyroid readings appear in the normal range but you still have the symptoms.

Symptoms of thyroid imbalance
headaches?
Classic hypothyroid symptoms:

• Coarse hair and hair falling out easily
• Dry or scaly skin
• Constipation
• Slow but steady weight gain
• Feeling cold all the time
• Having no energy

Other hypothyroid symptoms:

• Inability to lose weight
• Irritability and moodiness
• Fertility problems (men and women)
• Women: PMS
• Women: Cramping
• Women: Heavy flow
• High blood cholesterol
• Cognition and memory difficulties
• Mild depression
• Premature end to growth in young people
• Arm and leg muscles ache and cramp even when not in use
• Joint pain

Classic hyperthyroid symptoms:

• Boundless energy
• Always hot
• Jittery
• Hard to sleep
• Weight loss
• Heart palpitations

Other hyperthyroid symptoms:

• Oily skin
• Oily hair
• Excessive sweating, especially your palms
• Moist skin
• Red skin
• Feeling edgy or irritable

Pregnancy and menopause can cause symptoms that seem like underactive thyroid. They can also cause temporaty hypothyroidism. This makes diagnosis difficult so make sure your doctor is on the ball with this.

When you should get tested
You should get tested for a baseline when you are 35 and then get tested every 5 years after that until you are 60. After that you should be tested once a year.

The book has a set of questions to help you decide whether you should get checked for thyroid imbalance but I think if you find you have some symptoms on the list above and nothing seems to help then that’s probably a good sign.

Endocrine basics
The endocrine system is made up of glands that produce hormones that signal various actions throughout the body. The thyroid is part of the endocrine system and fluctuations in one part of the endocrine system influence others. Here are the glands that have an effect on the thyroid and the hormones they release:

• Hypothalamus
  • Corticotropin Releasing Hormone (CRH) – Directs the Pituitary to release ACTH
  • Thyrotropin Releasing Hormone (TRH) – Directs the Pituitary to release TSH
• Pituitary
  • Adrenocorticotropic Hormone (ACTH) – Directs Adrenals to release cortisol
  • Thyroid Stimulating Hormone (TSH) – Directs the Thyroid to release T3 and T4
• Thyroid
  • Thyroxine (T4) – Directs cellular metabolism (long-acting)
  • Triiodothyronine (T3) – Directs cellular metabolism (short-acting)
• Parahyroid
  • Parathyroid Hormone (PTH) – Regulates calcium and phosphate levels

If the thalamus detects that the levels of circulating thyroid hormone are too low it signals the hypothalamus to release TRH which signals the pituitary gland to release TSH which in turn gets the thyroid releasing its hormones. When the levels get high enough the hypothalamus stops producing TRH which stops the whole cycle. It is very rare that the hypothalamus is the root cause of a thyroid problem. If the pituitary gland is the problem then it is likely because a tumor is affecting the pituitary. Fortunately, it is rare that the pituitary is at fault in thyroid related matters.

How the thyroid works
The thyroid produces T4 and T3. The number in the name indicates how many iodine atoms it contains in its molecular structure. The TSH that the pituitary releases determines the ration of free and bound T3 and T4 in your blood. It is though that T2 binds to mitochondrial units and influences how much energy they can produce. Little is known about T2 though, but it is no longer thought o be inactive.

About 80% of the thyroid hormone floating around is T4, leaving most of the rest to be T3. Most thyroid hormone is in bound form (attached to other proteins). About 1% of T4 is freen and 5% of T3. As your cells use T3 and T4 the bound forms detach and become free keeping the free level constant.

Free T3 and T4 can enter cells to do its work with T4 acting on the order of days and T3 acting immediately and being used up. If there is a shortage of T3 the liver will convert T4 to T3, but the results of the conversion can be T3 or reverse-T3 (rT3). T3 speeds up metabolism and rT3 slows it down.

T3 works by binding with the cell’s thyroid receptor and opening it up to receive oxygen which then allows the chemical reactions that fuel the cell.

Diagnosis
Diagnosis of a thyroid imbalance is made difficult by not just finding a doctor to consider the possibility of a thyroid problem, but then figuring out what normal really is. Two-thirds of people with a thyroid condition will have clear, definitive test results. The normal that is listed on blood tests is a range of what has been found to be normal for a wide range of people. For some people the low end might be normal and for someone the middle of the range might be low for them. Getting your thyroid lever to lie in this range isn’t good enough. Everyone has a different normal. Not only that, but the problem might not show up inthe levels but might be in the interactions of the elements in the thyroid chain which won’t show up on a simple blood test.

To aid this you should get a baseline thyroid reading then you are 35 and then every 5 years after that. Also you should find a doctor who will take into account all of your symptoms and not just look at lab reports.

Your doctor
Your doctor should feel your thyroid for swelling or nodules and order a comprehensive series of lab tests to measure your thyroid functions. Your doctor should order follow-up tests as necessary. Your doctor should ask questions similar to the ones listed above. Your doctor should be willing to work with yout o find your balance.

The testing
There are a number of blood tests that can be run and with the most basic being one that looks at the levels of TSH and total T4 in the blood. The blood tests can be affected by factors such as birth control pills, hormone replacement therapy (HRT), estrogen replacement therapy (ERT), beta blocker meds, seizure meds, and low carb diets.

The following tests can more or less stand on their own as indicators but work better taken as a whole:
• A TSH or sTSH test measures the thyrois stimulating hormone in your blood. If this is too high it indicates that your thyroid is not producing what it needs which is making the pituitary put out more. > 2 microunits/mililiter (mU/mL) is a mild indicator. > 5mU/mL is pretty much conclusive. Range: 0.5 mU/mL – 5.5 mU/mL
• A total T4 test measures the T4 bound and free level of T4 in your blood. Low T4 indicates underactive thyroid, especially in the presence of high TSH. ERT can lead to elevated T4 without hyperthyroidism. Range: 4.6ug/dl – 12ug/dl
• A total T3 test measures the bound and free T3 in your system. Elevated levels indicate hyperthyroidism and low levels indicate hypothyroidism, but steroids and some blood perssure meds can result in a low T3 test. Range: 80ng/dl-180ng/dl
• Resin T3 and Resin T4 Uptake tests determine whether the thyroid hormone in the system is being bound, or if there is a binding problem. It is valuable only in conjunction with a total T3 or total T4 test. High T3/T4 and low resin uptake or low T3/T4 and high resin uptake indicates underactive or overactive thyroid respectively. Low/low and high/high indicate a binding problem. Estrogen from sources such as birth control pills, or hormone replacement therapy binds to the same receptors as thyroid hormone thus blocking the thyroid hormone and causing problems.
• Free T4 measures free T4. Range: 0.7-1.9ng/dl
• Free T3 measures free T3. Range: 230-619pg/dl
• Radioactive iodine uptake. A small amount of radioactive iodine is given and then they watch to see how much is brought into the thyroid (the only organ that uses iodine). Low levels correspond to underactive thyroid and high levels to overactive thyroid. Range: 10-30%
• Body temperature when plotted over time can give an indication of thyroid health. Use a mercury thermometer under your arm on first waking for ten minutes every morning for ten days. If the average temperature is below 98.2 degrees F then you likely have an underactive thyroid. This can help resolve inconclusive test results. The reverse is not true with temperature and hyperthyroidism though.

There are other more exotic tests that are discussed in the book which might be necessary to nail things down but if you are to that point you are probably already discussing them with your doctor. If your doctor isn’t discussing them with you then you should get the book and read about them.

When to get re-tested
If you are on a stable dosage of thyroid supplement then you should get re-tested every year to make sure it’s still the right level for you. Also, if you have a change in body weight greater than 10 percent you should also get re-tested since that impacts the needs of thyroid hormone on your body.

How foods impact thyroid function

Foods that slow down thyroid function
• Soy products
• Herbs you may take during menopause
• Cruciferous vegetables (broccoli and such)

Foods that aid thyroid function
• Selenium supplements aid the production of T4 and T3
• Tyrosine – a protein found in meat and fish is necessary for T3 and T4 production
• Iodine (from seafood, sea salt, or iodized salt) is necessary for proper thyroid function

Soy products

Treatment
Finding the right treatment can be as difficult as getting the right diagnosis. The right diet and lifestyle can help. Also finding the right supplement if you are hypothyroid can be a slow and frustrating process of adjustment and retesting that can take many months. Different supplements use different binder and different people absorb those in different ways. Natural sources of thyroid hormone will also have T3 in addition to T4 and that might be too much for your body.