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Thyroid

In April 2009, our guest expert was Dr. Sandra Kim, staff endocrinologist at Women’s College Hospital.

Dr. Kim is the medical director of the Endocrine Obstetrics Program at Women’s College Hospital. She also practices in the Multidisciplinary Osteoporosis Program and the general endocrinology clinic. She has a particular interest in pregnancy and reproductive endocrine disorders, specifically the management of diabetes and thyroid disorders in pregnant women. She is also an assistant professor at the University of Toronto where she teaches medical students, residents and endocrinology fellows. Sandra was the recipient of the 2007 Young Clinician Education Award.

Here are her answers on Thyroid.

Q: I have been taking Thyroid for 10 years. Once I started, the constant aching throughout my whole body (previously diagnosed as fibromyalgia) ceased. Synthroid never gave me this relief. Do you support the use of Thyroid (or Armour Thyroid as it is called in the U.S.)?

Q: Is thyroid medication derived from animal or synthetic sources and if from both, which is better?

Q: What alternative treatments are available for hypothyroidism?

A: The current standard for treating hypothyroidism is using levothyroxine, a synthetic preparation of the thyroid hormone T4. Synthroid and Eltroxin are examples of levothyroxine. Since T4 hormone is converted naturally by your body to T3 hormone, it is not necessary to take T3 in addition to T4.

Armour Thyroid is an example of desiccated thyroid or thyroid extract from porcine, which contains a mixture of both thyroid hormones, T4 and T3.

Most endocrinologists, including myself, generally do not recommend using desiccated thyroid preparations like Armour Thyroid for a number of reasons. To date, studies have shown no benefit to taking T4 plus T3 compared to taking T4 hormone alone. In an otherwise healthy person, the amount of T4 converted to T3 is under constant physiologic regulation, changing in response to the changing needs and demands of the body. Taking a mixture of T4 and T3 increases the risk of greater fluctuations of T3 throughout the day. Moreover, studies have shown large ranges of thyroid hormone content and potency in desiccated thyroid preparations, which can make dosing difficult.

Due to its high purity, ease of control in dosing, and effectiveness in the majority of people, levothyroxine is the standard therapy for hypothyroidism.

 


Q: What can I do for thinning hair and brittle nails? I am 63 years old and have been on thyroid and natural desiccate for about 25 years.

A: There are many possible causes for thinning hair and brittle nails other than from thyroid problems. If you are on thyroid medications you should check with your doctor to make sure that you are on the proper dose according to your blood test results. Your doctor may want to do other blood tests to look for other causes of your symptoms (such as iron deficiency). Management options for thinning hair and brittle nails will depend on the underlying cause(s).

 



Q: I have a hypothyroid condition that is balanced with daily medication. If it is balanced why is it still so difficult to overcome the fatigue and sluggish metabolism that results in slow weight loss?  Do you have any tips for how to feel more energetic?

A: There are many factors and conditions that can affect a person’s energy level, metabolism and weight. If your hypothyroidism is well treated with the proper dose of thyroid hormone medication (based on blood tests done by your doctor) then it is unlikely that it is a significant contributing factor for your symptoms. Conditions such as menopause, depression and some metabolic disorders and disease states may cause difficulties with weight loss, poor energy and fatigue. In addition, factors such as stress, sleep, diet and physical activity play an important role in energy level, metabolism and weight control. It is important that you discuss your specific symptoms with your doctor to rule out any conditions or disease and to get individual advice on healthy eating, physical activity and stress management.

 


Q: I would really like to know what food shouldn’t be eaten when you are taking Synthroid. I have taken this medication for hypothyroidism for several years and hear all kinds of recommendations, for example, do not eat cabbage.

Q: Why do you have to consume food one hour after taking the thyroid pill in the morning? 

A: Synthroid (levothyroxine) should be taken on an empty stomach with water, and certain foods should be avoided to ensure proper absorption of the medication dose. Foods with high sources of calcium (such as dairy products), fibre (such as cabbage), iron and soy can interfere with levothyroxine absorption. Vitamin and mineral supplements containing calcium and iron should also be separated from your levothyroxine for the same reason. These foods and supplements can simply be taken at a later time to prevent any issues with absorption of your thyroid medication.

In addition, waiting about an hour before eating after taking Synthroid improves absorption of the medication. It is best absorbed on an empty stomach.

 


Q: I have been on thyroid medication for a number of years for hypothyroidism. My doctor monitors my condition regularly and over the past year has had to change the dosage of my medication a number of times. She is not sure why. She sent me for an ultrasound of the neck and the results came back fine. I feel fine other than being tired all the time. I don't sleep well so I'm not sure whether that is the reason for being tired or whether it is because of my thyroid. What are the possible reasons for the ups and downs?

A: If you have already been on levothyroxine for hypothyroidism for many years there may be several reasons why your doctor has had to adjust your thyroid medication dose. First, it is important to ensure that you have been taking your thyroid medication consistently every day (preferably at the same time of day) and not missing any doses. Also, it is important that you have been separating the thyroid medication from certain foods and supplements that are high in calcium, iron and fibre, and which can affect its absorption. Inconsistency in when and how you take your thyroid medication can lead to fluctuations in the thyroid hormone levels in the blood, and may lead to frequent need for dose adjustment. Another potential reason for a dose adjustment may be if you had a significant change in your body weight. Generally, a smaller dose is required for lower body weight (and the opposite for higher body weight).

Certain illnesses and disease conditions may also affect the thyroid medication dose. Physiological changes such as pregnancy often will lead to the need for dose adjustment in your thyroid medication. Some medications can affect the dosing of thyroid medication. These include birth control pills and hormone replacement therapy, and drugs that may interfere with the absorption of thyroid medication.

Any time your levothyroxine dose has been adjusted by your doctor, it takes at least four to six weeks to reach a new normalization level of thyroid hormones in your blood. It is important to consider all of these potential factors with your doctor when your thyroid medication dose requires adjustment after many years of therapy for hypothyroidism. In cases where it remains unclear why the dose requires frequent changing, it would be reasonable to be referred to an endocrinologist for further assessment.   

 



Q: How likely is it that the following symptoms are related to thyroid?

  • puffy eyes
  • lack of energy in the afternoons (even if I am just relaxing at home)
  • being very cold all day (after being out in the cold with my kids) unless I take a very hot bath
  • frequent colds
  • irregular periods (though I am 43 so perhaps that can happen)...
  • snoring

Q: What are the symptoms of Hashimoto’s disease?

A: Many of the symptoms you have mentioned may be related to hypothyroidism (underactive production of thyroid hormone). Blood tests by your doctor can confirm whether these symptoms are related to hypothyroidism. If hypothyroidism is diagnosed, then treatment involves replacement therapy with levothyroxine (T4 thyroid hormone).

Hypothyroidism that is not treated can lead to a myriad of symptoms of varying degree, depending on the severity of hypothyroidism. Symptoms may also differ widely from one individual to another.

Symptoms of hypothyroidism may include: fatigue, low energy, weight gain or difficulty losing weight, cold intolerance, constipation, muscle ache, dry skin, puffy skin, hair loss, brittle nails, low mood and depression, difficulties with concentration or memory, menstrual irregularities and difficulties with conception.

Hashimoto’s thyroiditis is the most common cause of hypothyroidism. It is a chronic autoimmune condition whereby auto-antibodies produced by your body are directed against the thyroid gland. Over time, these antibodies attack the thyroid gland, rendering it underactive in its function to produce adequate thyroid hormones. In many cases of Hashimoto’s thyroiditis, these auto-antibodies can be measured in the blood. People with Hashimoto’s thyroiditis may also have an enlarged thyroid gland.

 


Q: What are the causes of clinical hypothyroidism and why is it routinely misdiagnosed? My general practitioner insists there is no problem with my thyroid yet my naturopath tells me there is.

A: The most common cause of hypothyroidism is Hashimoto’s thyroiditis, a chronic autoimmune disease which I describe in the previous answer. Other common causes of hypothyroidism include severe iodine deficiency, thyroidectomy (surgical removal of the thyroid gland) and history of radioactive iodine ablation of the thyroid gland. Some medications can potentially cause hypothyroidism. These include lithium, amiodarone and over-treatment on anti-thyroid medication such as PTU (propylthiouracil).

Another condition called “thyroiditis,” which is inflammation of the thyroid gland, can often lead to transient hypothyroidism. This may or may not be accompanied by pain of the thyroid gland itself and the neck area. Thyroiditis can commonly occur after pregnancy and is called “postpartum thyroiditis” when this is observed. With an episode of thyroiditis, usually there is an initial hyperthyroid phase followed by transient hypothyroidism. Most people recover from an episode of thyroiditis with normalization of thyroid hormone production – usually within six months. However, a very small percentage of people may end up with permanent hypothyroidism and will require levothyroxine therapy. Sometimes your doctor may have checked your thyroid hormone levels due to symptoms of hypothyroidism, and the results may have been “normal” if the blood test was done at a time when the thyroiditis was recovering. If you are recovering from an episode of thyroiditis, the symptoms of hypothyroidism may take longer to resolve than the normalization of your blood work.

Other very rare causes of hypothyroidism include problems with the pituitary gland or hypothalamus in the brain, or congenital causes such as being born with an under-developed thyroid gland.

 


Q: Does hypothyroidism cause muscle spasms causing residual soreness? I have an underactive thyroid condition (Hashimoto’s disease) and seem to have sudden breakouts on my skin. Is this a symptom and what can I do to prevent it?

A: Yes, muscle soreness or ache can be related to hypothyroidism. In addition, hypothyroidism can lead to dry skin which can increase the propensity for breakouts on the skin. If you have hypothyroidism, it is important to check with your doctor that you are on the proper dose of levothyroxine, based on a blood test. If your dose of thyroid hormone is confirmed to be adequate, then you should see your doctor for other possible causes of muscle aches and skin breakouts.

 


Q: How low does your TSH have to be in order to receive treatment for it?  Is it possible to have ‘borderline’ or ‘mild’ hypothyroidism so that blood tests such as T3 and T4 do not detect a problem? 

A: A “low” TSH (thyroid-stimulating hormone) indicates an overactive thyroid gland (hyperthyroidism), which has a different treatment than hypothyroidism. The treatment for hyperthyroidism will depend on the cause.

A “high” TSH indicates an underactive thyroid gland (hypothyroidism), which is treated with levothyroxine (T4 thyroid hormone). It is possible to have “mild” or “borderline” hypothyroidism when the TSH is mildly elevated at the upper limit of the reference normal range, while your actual thyroid hormones (T4 and T3) are still in the normal range. This “mild” or “borderline” hypothyroidism is known as subclinical hypothyroidism. There is still a lot of debate on whether subclinical hypothyroidism should be treated or not, but generally treatment is not recommended unless there is further progression, or under certain circumstances (such as pregnancy). Until further studies are available, each person with subclinical hypothyroidism should be assessed separately, looking at individual factors and potential risks and benefits to levothyroxine therapy.

 


Q: How closely should a pregnant woman be monitored if she has a low TSH (with or without medicine)? 

A: Any pregnant woman with a thyroid dysfunction (whether a low TSH indicating hyperthyroidism, or high TSH indicating hypothyroidism) should be monitored closely during pregnancy with a blood test done generally every four to six weeks, particularly if they are on medication for their thyroid condition. Blood testing may no longer be necessary if the thyroid dysfunction resolves on its own (without any treatment) during the pregnancy. Often it is also important to check thyroid with a blood test after pregnancy.

 


Q: I have a nodular goiter. I would like to know if I will be able to conceive and carry a pregnancy without complications.

A: Generally, having a nodular goiter should not affect your ability to conceive and carry a pregnancy, as long as your thyroid hormone levels are normal. If you have a nodular goiter, you should have your thyroid blood level checked with your doctor to ensure that it is in a normal range for pregnancy. In addition, you should check with your doctor that your thyroid nodules are not too large or growing rapidly, which may require further investigations.

 


Q: As a mental health therapist I often encounter clients with complex medical as well as emotional problems. I wonder about the effect of thyroid disorders on mood, in particular a type of unrelenting depression that seems to have no other trigger or cause. Could you also comment on the interactions between other hormones/neurotransmitters and thyroid hormones?

A: It is well known that thyroid dysfunction (both hyperthyroidism and hypothyroidism) can affect mood and play a role in exacerbating many mood disorders such as depression. In addition, there are some disorders (such as psychosis), as well as therapies used to treat mood disorders (such as lithium) that can trigger thyroid dysfunction. Therefore there seems to be an interaction between mood and thyroid function. Thyroid hormones act upon nuclear receptors that modulate the transcription of many genes that control energy balance and metabolism, and this may also include the regulation of other hormones and neurotransmitters. Some studies have also suggested an association of thyroid auto-antibodies and mood disorders (in particular, postpartum thyroiditis). Until further studies are available (both basic science and clinical research), it is important to ensure that thyroid indices are checked in all persons with a mood disorder and to ensure optimization of the thyroid indices with appropriate treatment if thyroid dysfunction is discovered.

 

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