Low-T3 Syndrome – Strong Predictor of Death from Heart Disease
It’s nice to see some researchers focusing on T3. Keep in mind that the thyroid produces mainly T4, which has a much lower activity than T3. The T4 makes it to the target tissues such as liver and muscle and gets converted to T3 where it’s needed. Well, that conversion is dependent upon several factors (nutritional, cortisol levels, estrogen levels…) and many people with thyroid problems are given synthetic T4 (synthroid, levothyroxine) and their blood levels look good but they still have all the signs and symptoms of hypothroidism. These people may underconvert T4 to T3.
Circulation — Abstracts: Iervasi et al. 107 (5): 708