Beyond TSH: Unlocking Thyroid Health with T3 and rT3

Resources

Books

• "Rethinking Hypothyroidism" by Antonio Bianco, M.D., Ph.D. - Explores the science, controversies, and patient experiences surrounding thyroid hormone replacement therapy.

Articles & Papers

• Studies on the effect of iodine intake on autoimmune thyroid disease - Mentioned as a reason for increased incidence of autoimmune thyroid disease in populations with high iodine intake.
• Studies showing that patients taking selenium, vitamin D or other antioxidants can reduce the levels of TPO and prolong the honeymoon period in Hashimoto's disease. - Discussed as a potential way to manage autoimmunity, though not standard clinical care.
• Studies showing that the safety of desiccated thyroid extract is identical to levothyroxine. - Used to support the safety of desiccated thyroid extract.
• Studies showing that patients tend to prefer combination therapy (T4 and T3) over levothyroxine alone. - Indicates patient preference for combination therapy.
• Studies comparing immunoassay with mass spec for T3. - Highlighted the importance of mass spectrometry for accurate T3 measurement, especially at lower levels.
• Studies showing that patients taking combination therapy (T4 and T3) had a reduction in mortality compared to levothyroxine alone. - Presented as evidence for the benefit of combination therapy.
• Studies showing that in the first year of levothyroxine treatment, 20-30% of patients use more than one formulation (generic vs. brand). - Illustrates the variability in levothyroxine formulation use.
• Study showing that a compounded controlled-release T3 product was proven to be identical to immediate-release T3. - Questions the efficacy of compounded slow-release T3.

People Mentioned

• Dr. Antonio Bianco (Senior Vice President and Dean at UTMB, internationally recognized expert in thyroid physiology and metabolism) - The guest expert on thyroid function.
• Dr. Ted Kendall (Mayo Clinic) - Credited with crystallizing levothyroxine in 1914.
• Dr. Selenko (Harvard Medical School) - Conducted studies in 1965 on T4 to T3 ratios.
• Catherine E. Ben - Author of an exposé on generic vs. branded drugs.

Organizations & Institutions

• American Thyroid Association - Dr. Bianco previously served as its president.
• UTMB (University of Texas Medical Branch) - Where Dr. Bianco currently serves as Senior Vice President and Dean.
• John Sealy School of Medicine - Part of UTMB.
• United States Pharmacopeia (USP) - Established a mass spec method for measuring T3 and T4 in desiccated thyroid extract in 1985.
• FDA (U.S. Food and Drug Administration) - Mentioned in relation to drug approvals, recalls, and regulatory pathways.
• American Thyroid Association - Their 2012 guideline suggested treatment with branded levothyroxine.
• Brigham and Women's Hospital - Where Dr. Selenko conducted studies on T4 to T3 ratios.
• AbbVie - The company that makes Synthroid.
• Mayonnaise Clinic - Where Ted Kendall worked.

Other Resources

• Hypothalamus-Pituitary-Thyroid Axis - The core physiological system discussed.
• Deiodinase Enzymes (D1, D2, D3) - Enzymes crucial for activating and inactivating thyroid hormone.
• Thyroid Hormone Receptors - Proteins that bind to thyroid hormones.
• Brown Fat - Discussed in the context of T3 conversion and thermogenesis.
• Blood-Brain Barrier - Mentioned in relation to the hypothalamus's access to peripheral hormones.
• TPO Antibody (Thyroid Peroxidase Antibody) - An antibody associated with Hashimoto's disease.
• Anti-Thyroglobulin Antibody - Another antibody associated with autoimmune thyroid conditions.
• TPO (Thyroid Peroxidase) - An enzyme involved in thyroid hormone synthesis.
• Thyroglobulin - A protein produced only in the thyroid.
• Subacute Thyroiditis - A painful inflammation of the thyroid.
• Congenital Hypothyroidism - A defect present at birth affecting thyroid hormone production.
• Postpartum Thyroiditis - Hypothyroidism that can develop after childbirth.
• T4 Monotherapy (Levothyroxine) - Standard treatment for hypothyroidism.
• T3 Monotherapy (Liothyronine) - Less common treatment for hypothyroidism.
• Desiccated Thyroid Extract (DTE) - Thyroid hormone replacement derived from pig thyroid glands.
• Synthetic Combination Therapy (T4 and T3) - Combination of synthetic T4 and T3.
• Synthroid - A branded formulation of levothyroxine (T4).
• Cytomel - A branded formulation of liothyronine (T3).
• Armour Thyroid - A brand of desiccated thyroid extract.
• Nature-Throid - A brand of desiccated thyroid extract.
• LCMS (Liquid Chromatography-Mass Spectrometry) - A more accurate method for measuring hormone levels, particularly T3.
• Immunoassay - A common but less accurate method for measuring hormone levels.
• CLIA (Clinical Laboratory Improvement Amendments) - Regulations for laboratory testing.
• Propensity Score Matching - A statistical method used to control for confounding variables in observational studies.