The Problem with Mainstream Thyroid Testing and Treatment
Today’s mainstream clinical practices surrounding detecting and treating thyroid conditions are lacking. This predicament has left many thyroid sufferers without answers. Inadequate lab testing, along with a vast reference gap in lab ranges, leaves many thyroid conditions undetected and untreated.
It is estimated that 20 million Americans have some form of thyroid disease; these numbers continue to increase each year. Nearly 60% of those with thyroid disorders are unaware of their condition. Undiagnosed thyroid conditions put patients at risk for additional severe conditions, such as heart disease, infertility, osteoporosis, and weight gain/loss. Other common thyroid-associated issues include but are not limited to, poor fat digestion, gallstones, fatigue, brain fog, constipation, diarrhea, infertility, and joint pain.
Pregnant women with hypothyroidism and subclinical hypothyroidism have a higher risk of miscarriages and have a greater chance of giving birth to children who have congenital disabilities and/or developmental conditions.
When mainstream testing standards finally do detect thyroid disease, an affected individual has likely had to suffer for a long time. Often, thyroid conditions are undetected until they have reached the full-blown disease stage. Early detection would undoubtedly improve clinical outcomes.
Today’s Standard Lab Tests and Ranges
It is common practice among mainstream medical professionals to measure the thyroid-stimulating hormone (TSH) with bloodwork to assess thyroid function. However, when measured alone, TSH is not an accurate marker for thyroid function. Even with the addition of one or two thyroid hormone markers, there is still not enough information to confirm that there is or is not a thyroid condition present.
These standards need to change, but until then, there will be many who suffer for years, if not an entire lifetime, with an untreated and undetected thyroid condition.
Thyroid Hormone Influence on the Body
Thyroid hormone output is controlled by stimulating TSH in a healthy functioning thyroid. The thyroid hormone is released from the thyroid gland in response to TSH. These thyroid hormones are called Thyroxine (T4) and Triiodothyronine (T3).
Without adequate thyroid hormone, many processes within our body will not function as they should. It is believed that every cell in our body has thyroid hormone receptors.
When thyroid hormone is present, it is transported into the cell, where it binds to a nuclear receptor. This then initiates a process called transcription. Transcription is responsible for reading genetic material that can then be translated into specific proteins that can be used for physiological function throughout the body.
Since T3 activates transcription, the processes that T3 is specific to don’t occur if T3 is absent. An example of this would be myosin. Myosin is a cardiac protein responsible for increasing the contractility of the heart. Adequate T3 is needed for the production of myosin. A lack of myosin results in reduced contractility of the heart muscle and, ultimately, results in the cardiac complications that may be seen with hypothyroidism.
Thyroid Hormones Help Regulate
- Basal Metabolic Rate (BMR)
- Heart rate
- Body weight
- Muscle strength and control
- Central and peripheral nervous systems
- Bone maintenance
- Fat digestion and lipid levels in the blood (increased cholesterol, LDL, and/or triglycerides can be indicative of low thyroid hormone)
- Menstrual cycles
- Mood
- Breathing rate/rhythm
TESTING FOR THYROID FUNCTION
Given the importance of thyroid function, it is essential to test the function of the thyroid properly. To get an accurate assessment, the following laboratory blood markers should be tested:
- TSH
- T4
- T3
- Reverse T3
- Free T4
- Free T3
- T3 Uptake/TBG
- Thyroid Peroxidase (TPO) Antibodies
- Thyroglobulin (Tg) Antibodies
Additional Testing
If hyperthyroidism is suspected:
- TSH Antibodies
- Thyroid Receptor (TR) Antibodies
Imaging
- Thyroid Ultrasound
Test 1: TSH
The demand for thyroid hormone output from the thyroid is controlled through a feedback loop. The hypothalamus and the pituitary are both a part of this loop.
As blood levels of thyroid hormone decrease, the hypothalamus releases the thyroid-releasing hormone TRH, which signals the pituitary to release the thyroid-stimulating hormone TSH. The TSH then acts upon the thyroid, signaling the need for an increase in thyroid hormone output T4 and T3 from the thyroid.
In a perfect scenario, an increase in TSH results in an increase in thyroid hormone output. A decrease in TSH results in a reduction in thyroid hormone output. Once the body reaches sufficient thyroid hormone production, TSH should respond accordingly by either lowering when there is enough hormone or rising when there is not enough.
This inverse relationship between TSH and thyroid hormone is why a high TSH can be seen in cases of hypothyroidism – low thyroid hormone output and a low TSH in cases of hyperthyroidism – high thyroid hormone output.
Unfortunately, this perfect scenario does not always work out in real life. TSH is not always so intuitive.
Reasons Why You Need to Have More Than Just TSH Tested
- You can have TSH well within lab range and still have low thyroid hormone output. TSH is not a direct thyroid hormone measurement and may not reflect actual thyroid function.
- A malfunctioning Hypothalamus-Pituitary-Adrenal or HPA axis can result in a poor TSH feedback loop.
- Literally, any other thyroid marker indicative of dysfunction can be out of lab range, which may or may not be reflected in TSH. This is very common.
- TSH measurement can be within lab range in the early stages of thyroid disease. This is where measuring thyroid hormones and antibodies, perhaps even a thyroid ultrasound, can be helpful.
- In autoimmune conditions, the thyroid is commonly destroyed slowly over time. TSH cannot reflect this until a significant amount of thyroid tissue has been destroyed from relapsing autoimmune attacks on the thyroid gland.
- Lab ranges are very forgiving. They are based on the averages of the local population. This does not mean it’s an optimal range, just comparative figures. TSH can be within lab range in an individual with thyroid disease.
- With thyroid hormone replacement, TSH is not an accurate measurement for adequate dosing. Thyroid hormones need to be measured as well.
TSH is a pituitary hormone that stimulates the thyroid to make thyroid hormone. It is not an accurate test alone for thyroid function. TSH should be in the range of 0.5 – 1.5 uIU/mL. Other thyroid markers also need to be taken into consideration.
Tests 2 and 3: T4 and T3
Thyroxine (T4) and Triiodothyronine (T3) are released from the thyroid gland when TSH is stimulated. Carrier proteins bind both. T4 is the storage or inactive form of thyroid hormone, making up about 93% of the thyroid hormone output. T3 is the active form, making up about 7% of this output.
As thyroid hormone circulates peripherally, T4 is converted to T3 by an enzyme catalyst called 5′ deiodinase. T4 circulates through the bloodstream and is converted at different points.
The largest amount (60%) of conversion occurs in the liver. A healthy functioning liver is a large piece to ensure conversion.
The GI tract converts T4 into T3 sulfate (T3S) and triiodothyroactetic acid (T3AC) until it enters the digestive tract and is acted upon by intestinal sulfatase. It then becomes T3. It is responsible for approximately 20% of T4 to T3 conversion. This is yet another reason for having a healthy microbiome.
Another portion (approximately 20%) is converted into reverse T3 (RT3). This is an inactive form of T3. In cases of illness or extreme stress, the conversion of RT3 can increase. Not only does it not provide the active effects of T3, but it also competes at the nuclear receptor sites with T3. This means a lowered ability for T3 to elicit its effects.
Test 4: Reverse T3
This test is not commonly ordered, however, this test is highly valuable.
Higher than usual RT3 (inactive hormone) means less T3 (active hormone). This problem is because high RT3 levels will slow metabolism and reduce thyroid function. This can result in the patient feeling hypothyroid.
Reverse T3 becomes elevated with
- Stress (high cortisol)
- Trauma
- Calorie restriction diets
- Inflammation
- Infections
- Toxicity
- Zinc deficiency
- Selenium Deficiency
- Certain medications
RT3 should be less than 15 ng/dL. A lab value higher than 15 ng/dL can indicate some form of stress on the body. RT3 will normalize once the root issue is addressed.
Remember that carrier proteins bind both T4 and T3. Because of this, they cannot be used by the cells until they become what we call “free.” The free thyroid hormone can bind to the nuclear receptor and be utilized by the cells for metabolic purposes. These free thyroid hormones are free T3 (FT3) and free T4 (FT4).
Test 7: T3 Uptake & TBG
T3 uptake or thyroxine-binding hormone (TBG) should be ordered to help access the amount of carrier protein in the blood. These two tests measure differently but give similar information.
Carrier proteins are those that attach to the thyroid hormone released from the thyroid (T4 and T3). They are called free T4 and free T3 when they lose the protein.
T3 Uptake
The T3 Uptake test is a way for practitioners to measure the number of sites available for thyroid hormone to bind to carrier proteins for transportation. It is an indirect measurement of the amount of thyroxine-binding proteins.
T3 Uptake is typically measured as a percentage. The lab range usually is 24-39%. Functional range is about 28-38%.
T3 Uptake will be low in cases where there is excess estrogen (estrogen dominance) or even if there is low thyroid hormone but normal or adequate estrogen levels.
T3 Uptake will be high in cases where testosterone levels are elevated. This could be found in conditions like PCOS, insulin resistance, hirsutism, and the intake of testosterone hormone.
TBG
TBG makes up most proteins that transport thyroid hormone throughout the body. High levels of TBG will result in lower free hormone levels. This decreases the amount of hormone that can enter the cells (FT4 and FT3).
Therefore, it can result in hypothyroid symptoms even with adequate thyroid hormone output. T3 Uptake and TBG have an inverse relationship. Consequently, you will have high TBG levels when you have low T3 uptake and low TBG levels when there is high T3 uptake.
Tests 8 and 9: Thyroid Antibodies
Elevated thyroid antibodies can be found in thyroid diseases like Hashimoto’s and Graves. Lab-high antibodies are needed for an autoimmune diagnosis, although an autoimmune thyroid gland disease can be present before thyroid antibodies are lab-high or even detected.
This mechanism begins when the body’s immune system creates antibodies to thyroid tissue. Many stressors are thought to induce this response.
Some Mechanisms That Can Lead To Thyroid Antibody Production
- Transfer of antibodies from the mother in utero
- Dysbiosis (Leaky Gut)
- Infections, Lyme, and H. Pylori
- Environmental Toxins (mold, heavy metals, chemicals)
- Stress (emotional and/or physical)
Hashimoto’s
Iodine deficiency is the most common cause of hypothyroidism worldwide. However, autoimmune thyroid disease is the most common cause of hypothyroidism in the United States. This form of autoimmunity, known as Hashimoto’s, is 5-10 times more common in women than men, and the incidence increases with age.
Hashimoto’s Antibody Tests
- Thyroid Peroxidase (TPO) Antibodies
- Thyroglobulin (Tg) Antibodies
Additional Tests – Grave’s Disease Antibodies
The overproduction of thyroid hormone marks Grave’s disease due to an autoimmune process on the thyroid gland.
Grave’s Disease Antibody Tests
- TSH Antibodies
- Thyroid Receptor (TR) Antibodies
- Thyroid Peroxidase (TPO) Antibodies
- Thyroglobulin (Tg) Antibodies
Additional Test: Thyroid Ultrasound
Thyroid ultrasounds are a very effective diagnostic tool. They provide a high-resolution image of the gland. Ultrasounds show evidence of thyroid dysfunction before any lab work does. Abnormal nodule findings can indicate a need for further testing.
Thyroid Ultrasounds Are Used For
- A diagnostic tool for early detection of thyroid disease
- Follow-up for abnormal thyroid blood work
- Abnormal findings in physical exam of the neck
Thyroid Ultrasounds Will Show
- Swelling (indicative of thyroiditis or an autoimmune condition)
- Blood flow throughout the gland
- Abnormalities (cysts, nodules, tumors)
- Nodule features (some features strongly correlate with a benign nodule while others correlate with cancer)
Conclusion
Thyroid disease lies at the root of many health issues, but using these testing methods will reveal and heal so individuals do not have to suffer as long.
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