HPT axis
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Targeting TSH? It’s not as specific or as sensitive as people claim.
Patients and doctors are often told there’s an ideal “target” for TSH levels. Some believe that in thyroid therapy, your TSH should be below the upper reference limit, some say it should be below 2.5, and a minority will even say it should be suppressed entirely whether or not you are a thyroid cancer patient.…
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In Winter, everyone gains T3 except thyroidless patients on LT4 therapy
In this article I examine the research results depicted in the graph above. Gullo and team’s 2017 article reported research on 11,806 healthy controls and 3,934 thyroidless people treated with L-T4 monotherapy in Sicily, Italy. They discovered that the thyroid-disabled people lost a “significant” amount of Free T4 and Free T3 hormone in winter, on…
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As of 2019, still no proof that low TSH causes harm to bones
Many research studies have shown a strong association between low TSH and low bone mineral density or osteoporosis. As a result, many guidelines strongly caution against the risk associated with low TSH. Some doctors and thyroid patients have jumped to the conclusion that a low TSH “causes” osteoporosis. Some even believe a low TSH must…
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Pregnancy thyrotoxicosis vs just a low TSH due to hCG hormone
Table 17.1 in Braverman & Cooper’s 2013 chapter in Werner & Ingbar’s The Thyroid textbook, 10th edition, lists many causes of thyrotoxicosis. One of the interesting causes of thyrotoxicosis, rarely mentioned in public discourse, is “Circulating hCG or Mutant TSHR [TSH receptor] hypersensitive to hCG.” What is hCG? “Human chorionic gonadotropin” is a hormone produced…
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How TSH ultrashort feedback works, and antibody interference
This post takes a closer look at the “ultrashort feedback loop,” the biological mechanism by which the TSHR stimulating antibody (TSAb) can oversuppress or inflate TSH in any autoimmune hypothyroid patient. The antibody’s effect alters the normal TSH-FT4 relationship. It may look like the patient has another thyroid condition: It may mimic “Resistance to thyroid…