Kenneth A Woeber1. 1. University of California San Francisco, San Francisco, California 94143, USA. ken.woeber@ucsf.edu
Abstract
OBJECTIVE: To quantify the relative contributions of thyroid secretion and peripheral generation to triiodothyronine (T(3)) production in untreated Graves' hyperthyroidism. PATIENTS, DESIGN, AND MEASUREMENTS: Thirty-one patients with hyperthyroidism, of whom 6 had T(3) toxicosis, and 21 surgically and radioiodine ablated patients with thyroid cancer on thyroid stimulating hormone-suppressive therapy in whom serum T(3) should reflect peripheral generation alone were compared with respect to serum free thyroxine (T(4)) and serum free T(3) concentrations. MAIN OUTCOMES: Serum free T(4)/free T(3) molar ratios were virtually identical in the patients with T(4)+T(3) toxicosis (2.7 +/- 0.4) and those with T(3) toxicosis (2.6 +/- 0.4) and were significantly lower than in the patients with thyroid cancer (4.0 +/- 0.4) (p < 0.001). In the hyperthyroid patients, peripherally generated T(3) was calculated as the quotient of the individual serum free T(4) concentration and the free T(4)/free T(3) molar ratio in thyroid cancer; this value was subtracted from the individual measured free T(3) concentration to derive the value for secreted T3. Secreted T(3) accounted for 33 +/- 6% of T(3) production in T(4)+T(3) toxicosis and 34 +/- 10% in T(3) toxicosis. CONCLUSIONS: This study indicates that about one third of T3 production in untreated Graves' hyperthyroidism, irrespective of whether presenting as T4+T3 toxicosis or T3 toxicosis, arises from thyroid secretion as compared to about 20% in normal individuals.
OBJECTIVE: To quantify the relative contributions of thyroid secretion and peripheral generation to triiodothyronine (T(3)) production in untreated Graves' hyperthyroidism. PATIENTS, DESIGN, AND MEASUREMENTS: Thirty-one patients with hyperthyroidism, of whom 6 had T(3)toxicosis, and 21 surgically and radioiodine ablated patients with thyroid cancer on thyroid stimulating hormone-suppressive therapy in whom serum T(3) should reflect peripheral generation alone were compared with respect to serum free thyroxine (T(4)) and serum free T(3) concentrations. MAIN OUTCOMES: Serum free T(4)/free T(3) molar ratios were virtually identical in the patients with T(4)+T(3)toxicosis (2.7 +/- 0.4) and those with T(3)toxicosis (2.6 +/- 0.4) and were significantly lower than in the patients with thyroid cancer (4.0 +/- 0.4) (p < 0.001). In the hyperthyroidpatients, peripherally generated T(3) was calculated as the quotient of the individual serum free T(4) concentration and the free T(4)/free T(3) molar ratio in thyroid cancer; this value was subtracted from the individual measured free T(3) concentration to derive the value for secreted T3. Secreted T(3) accounted for 33 +/- 6% of T(3) production in T(4)+T(3)toxicosis and 34 +/- 10% in T(3)toxicosis. CONCLUSIONS: This study indicates that about one third of T3 production in untreated Graves' hyperthyroidism, irrespective of whether presenting as T4+T3 toxicosis or T3 toxicosis, arises from thyroid secretion as compared to about 20% in normal individuals.
Authors: Cintia E Citterio; Balaji Veluswamy; Sarah J Morgan; Valerie A Galton; J Paul Banga; Stephen Atkins; Yoshiaki Morishita; Susanne Neumann; Rauf Latif; Marvin C Gershengorn; Terry J Smith; Peter Arvan Journal: J Biol Chem Date: 2017-07-25 Impact factor: 5.157
Authors: Martin Teufel; Katrin Elisabeth Giel; Jule Lehr; Sandra Becker; Michaela Muthig; Stephan Zipfel; Jürgen Kuprion Journal: Eat Weight Disord Date: 2013-03-29 Impact factor: 4.652