Reverse T3 in Patients With Hypothyroidism, Helpful or a Waste of Time?

Abstract Background: Reverse T3 (rT3) is a biologically inactive form of that created by peripheral 5 deiodination T4 type 1 and 3 deiodinases may block binding to the thyroid hormone receptor. As about 15% patients on L-T4 replacement with normalized TSH report continued fatigue other hypothyroid symptoms, efforts are needed understand why this occurs how it can be corrected. Decades ago, endocrinologists realized in severe illnesses, rT3 often high low termed “sick euthyroid syndrome”. However, more recently, alternative doctors, including functional medicine have argued detrimental from Without peer-reviewed publications, these doctors rely heavily levels treat no laboratory findings hypothyroidism prescribe them L-T3-only preparations try lower rT3. Also poorly characterized literature effects hypercortisolism hypopituitarism, both which should modulate expression increase Hypotheses: 1) Patient will vary significantly medication taken. 2) clinically significant management medications. 3) Hypercortisolism hypopituitarism levels. Methods: The most recent measurements were analyzed 621 currently being managed TCF. upper limit normal for at either Quest or LabCorp, usually 24.1 ng/dL was used as cut-off result below 9.2 cut-off. Results: Elevate seen 3% not (5/143), 8% (17/203) taking desiccated thyroid. It prevalent synthetic (27%, 7/26) (15%, 16/104) (9/58) alone. Changes made amount medications 199 patients. Levels outside range 27% (54/199), above 16% (32/199). 37 patients, 36 Cushing’s disease, however only 2 Hypopituitarism diagnosed 22 one had because they couldn’t afford their growth replacement. Conclusion: Measuring helpful who already treatments, greater importance preparations. recommended (even if experiencing hypercortisolism) adequate