Sunday, September 16, 2018

Thyroid hormones - a primer

I attended a conference last week on Integrative Medicine and Mental Health and there was a lecture on the thyroid gland. As a Functional Medicine physician I see many people with thyroid disorders, mostly hypothyroid, so I chose that lecture (they offered concurrent sessions) to hear the latest scoop on the thyroid. The thyroid is a complex little gland that sits at the base of your windpipe just above the jugular notch. It is often described as being shaped like a butterfly but I think it looks like upside down angel wings.

The graphic shows a schematic of how the hormones from the region of the brain called the hypothalamus signal the pituitary gland to then signal the thyroid to make more hormone. Like I said, it's a tricky gland. So the most interesting part of the lecture to me was that conventional thyroid testing has been shown in studies to miss thyroid dysfunction and that a thyroid gland that is underperforming may be associated with mood disorders, particularly depression.

How might you feel if your thyroid is sluggish? 
  •  You might notice that you rarely sweat or that you seem to be cold when everyone else is warm. 
  • You may be constipated
  • If you are female you may have menstrual irregularities or infertility problems
  • You may notice hair loss 
  • You might have difficulty losing weight or notice you gain weight easily
  • You may lose the outer third of your eyebrows
  • You may be feel fatigued
  • You may have difficulty concentrating
  • You may be depressed

If you two or more of the above symptoms, you may want to get your thyroid checked. Your doctor can examine your thyroid gland and see if it is enlarged. Most physicians were taught that the best screening test for thyroid function is TSH. This is incorrect! New studies show that up to 80% of thyroid dysfunction will be missed with just a TSH level. Ask you doctor to get a Free T3 level and a reverse T3 level along with the TSH. They may want to get a T4 or free T4 but these are secondary in importance to the Free T3 and reverse T3.

Conventional doctors may not realize that optimum levels of hormone are in the upper ranges of the 'reference range'. For example, if the reference range at your lab for Free T3 is 2.1 - 4.4, then your Free T3 should be around 4.0 for best function. Most people feel better once the Free T3 is above 3.2 but in Functional Medicine we think of a reference range as analogous to the normal range of shoe sizes. One size does NOT fit all and your 'fit' may be different from mine.

If you are already taking a thyroid medication it is likely that you were given a synthetic form of thyroxine or T4. Synthetic thyroxine is designed to act like T4 - the main hormone your thyroid gland makes. Unfortunately, sometimes things like stress, trauma, infection, inflammation and extreme dieting can cause the conversion of T4 into active T3 to be diverted. This diversion, shown on the graphic below, results in the T4 being converted to REVERSE T3 (which the lecturer dubbed the 'evil twin' of T3). 

Reverse T3 acts like a brake on the thyroid and prevents some of your T3 from gaining access to the cell nucleus (so it can't do it's job). It's a double whammy. The T4 can either turn into T3 OR reverse T3 so every time it converts to reverse T3 you have less T3 to work with AND the reverse T3 blocks the T3 from doing its job! You can see why it might be important to check the reverse T3 level.

If you think your thyroid may be dysfunctional - stay tuned! Next week I am at a conference but hope to post more about thyroid disorders, including autoimmune thyroiditis (Hashimoto's), and how they can be managed.

Today's De-stress meditation -
    'The more and more you listen, the more and more 
      you will hear. The more you hear, the more and more
       deeply you will understand.' -Khyentse Rinpoche

This is adapted from Luminous Mind by Joel and Michelle Levey:

Sit quietly and pause in your thinking and relax. You may want to set a timer for 3 - 5 minutes once you are ready to begin.

Take a comfortable posture, either sitting upright with feet on the floor and hands resting in your lap or lying down. Relax your forehead, soften the eyes, close the eyes and relax your jaw muscles and neck. Notice your body moving in rhythm with your breath. Begin to notice the sounds in your environment. Imagine your mind is an antenna, picking up all the arising sounds around you. In this state of receptivity, your mind is a place of awareness of sounds rising and falling into silence. Without thinking about the sounds, just let them come and flow. If your mind wanders off into thinking, just smile at yourself and mentally say, "Listen.." without judgment.
Notice how the sounds dissolve back into silence and how your listening mind is like the vast, clear sky that can contain limitless sounds without any getting in the way of the other. Breathe, listen and smile. 
When the timer sounds, if you used one, bring your awareness back to your breath for a few moments then open your eyes.



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