In Canada, the “Choosing Wisely Canada” campaign, together with the Canadian Society for Endocrinology and Metabolism, wants to declare Free T3 and Free T4 testing “unnecessary” in monitoring thyroid therapy.
- See the list of thyroid tests Choosing Wisely Canada claims are unnecessary within the field of Endocrinology and Metabolism
- This harmful policy is also on the CSEM website for all endocrinologists to see, under “Clinical Practice Guidelines and Quality Improvement“
As thyroid patients, we say NO.
The TSH test is not enough.
This is not a wise choice. It is a harmful choice.
How dare we disagree with the experts?
Every reasonable human being has the right — and the moral duty — to stand against a medical consensus when it conflicts with scientific research and biological facts.
Let’s talk reasonably about the research and the biological facts instead of being blinded by medical power and credentials.
Medical professional groups have their own agendas and reasons for maintaining their consensus when it is externally challenged.
This medical consensus conflicts also with patients’ own experiments in thyroid therapy. We are not passive lab rats. We carefully observe, examine, study all our parameters. We ponder, we hypothesize, we try changing variables, we observe results, and some of us keep meticulous records. We see the powerful effect of thyroid hormone levels and thyroid medication on our overall health and in the stories of fellow patients. When we read thyroid literature and the thyroid science, we read it with these experiments in mind. Over a lifetime of therapy, we can learn a lot about our unique condition. We build knowledge. We gradually advance from “thyroid therapy grade-school” to “thyroid science university” critical thinking. We have earned this knowledge, and we speak out for the sake of our health.
Consider the biology of thyroid therapy.
You are a patient without a functional thyroid gland, whether due to a thyroidectomy, a medical treatment, or autoimmune destruction.
You are fully dependent on external thyroid hormones.
TSH is powerless to adjust your thyroid hormone levels. Instead of naturally fine-tuning your body’s thyroid hormone secretion and conversion 24/7 as needed, you take static daily doses through your GI tract. Those doses can’t adapt. Instead, TSH adapts to them. Those doses now directly control your TSH and underneath that superficial TSH number, they can shift your T4 and T3 levels in unnatural ways.
Science tells you that “thyroid hormone receptors” in the nucleus of cells are located in your cardiovascular system, your bones, your brain, all your organs and tissues. Which hormone enters those receptors and has power to activate them?
Science says only T3 hormone has the power to enter those thyroid hormone receptors and initiate a complex chain of genomic activity to create energy and enable organs and cells to function properly.
You learn from scientific research that your entire body is extremely sensitive to T3 levels, even slight variations within the “normal” reference range. Health depends on the ability to defend T3 levels in blood and in peripheral tissues.
But you can’t adapt as your body’s “set point” for thyroid hormone shifts with the seasons, as the body’s need for T3 shifts up and down with health status, as it shifts parameters within the broad “normal” range in relation to diet and exercise, whenever you need to slightly lower or increase your metabolic rate. In the natural state, TSH and T3 even have a significant circadian rhythm that helps assist our daily ebb and flow of energy.
But you can’t adapt. Your static T4 and/or T3 hormone doses can only change after a lab test and doctor’s visit.
On long term maintenance, you might only get tested once a year for the rest of your life.
In this scenario, which hormone levels in blood, TSH, T4, or T3, are likely to be the most responsible for symptoms of hypothyroidism or hyperthyroidism during thyroid therapy?
The three hormones in biological priority
If you truly understand how the three hormones function at the molecular level in a person WITHOUT a fully functional gland who depends on external thyroid hormones, you will see this biological priority:
- Primarily, Free T3. Research shows thyroid patients can’t protect their T3 levels like other people, and protecting T3 is essential, so Free T3 testing is essential.
- Secondarily, Free T4. Free T4 carries the potential of becoming “Tomorrow’s T3.” But T4-T3 conversion can be slowed down. T4 can be converted either into active T3 or inactive Reverse T3. That’s why we need to see Free T4’s relationship to Free T3.
- Thirdly, pituitary TSH. In a thyroid patient without a thyroid gland who depends on external hormones, TSH has lost most of its potency:
- A high-normal or high TSH can’t fix a T4 deficiency, and especially not a T3 deficiency. A low TSH can’t prevent T4 or T3 excess.
- A low TSH doesn’t always signify excess T3. It can and does often co-exist with low or normal T3 in patients treated with oral thyroid hormone.
- Molecular biology has proven TSH plays an indirect role in increasing T4-T3 conversion to boost T3 supply in peripheral tissues. But will hormone therapy permit TSH to do this? If T4 dosing “normalizes” or even suppresses TSH and prevents it from rising, even a high level of T4 in blood is not going to convert to enough T3 in cells. Thus, a TSH deficiency alone cannot “cause” osteoporosis, but a TSH deficiency in the presence of T3 excess or deficiency can be truly pathological.
Our Canadian thyroid testing policies and “choosing wisely” guidelines are unwisely in the opposite priority order.
The hormone that matters the most to thyroid patients’ long-term health and present well being, Free T3, is hardly ever measured.
The hormone that matters the least in biological terms and is powerless to ensure our thyroid hormone sufficiency and balance, TSH, is too often the only one that will be measured.
How did we get to this point? Read “Why has TSH testing taken over thyroid hormone testing?”
Ethical and practical testing
Just as blood sugar monitoring is important for diabetics, T3 and T4 monitoring is important for thyroid patients. They have trouble regulating blood sugar levels; we have trouble protecting our T3 levels within optimal range.
Doctors must not be discouraged from ordering these tests to optimize thyroid patients’ T3 and T4 thyroid hormone levels to protect their lifelong health.
These tests must remain accessible and covered within provincial health care plans. Thyroid hormone tests help ensure that patients on lifelong thyroid hormone therapy an be healthy, active, contributing Canadians.
Where CAN we save money on thyroid testing?
First of all, why should our society save money on thyroid testing at this time?
- Haven’t we saved millions already, paid for by human suffering, in the decades that TSH testing has overruled and blinded thyroid therapy?
- Pick on a rarer condition, a less impactful disorder, a more temporary health issue, to save money.
- Our time as thyroid patients has come. Give our therapy a chance to be therapeutic.
Secondly, we will earn and save more money by testing properly.
- Thyroid patients will remain employed longer, will grow the economy, and will pay the taxes to support other people’s health care.
- We will have more brain power at work, less absenteeism, and all our energy will be available for productivity.
- Our society will save a lot of money by not having to test for and treat thyroid patients for the diseases they would be more likely to get because of poorly managed lifelong thyroid hormone therapy.
- We’ll become healthier mothers and fathers raising healthier young citizens who make money and save money while living life fully. Healthy, retired grandparents can save families a lot of money on daycare and babysitting.
However, we can make a practical suggestion:
In patients with a benignly suppressed TSH, don’t test TSH. Just test T4 and T3.
Thyroid Cancer patients’ TSH is therapeutically suppressed after high-risk thyroid cancer in order to prevent TSH from stimulating cancer regrowth. If you already know that a given dose suppresses their TSH, why test TSH over and over? On the other hand, they do need their T4 and T3 tested regularly because a person without a thyroid gland is at risk of very low T3, especially if they are on L-T4 monotherapy.
In other patients maintained on T3-based therapies such as T3/T4 combination therapy (or desiccated thyroid, which is animal-derived thyroid combination therapy), a benignly low or suppressed TSH is often necessary for optimal T3 levels, due to T3’s unique oral dosing side-effects. These side effects are largely isolated to the hypothalamus and pituitary gland’s secretion of TRH and TSH, respectively, and the T3 dose affects the rest of the body quite differently. Meanwhile, their T3 levels must be monitored in addition to metabolic signs and symptoms to ensure that they are neither under- nor over-dosed on their maintenance T3/T4 dose.