A Serum Thyroxine Method: Application in Thyroid Disease and Iodine-Treated Patients

Abstract

A practical method for measuring serum thyroxine levels has been developed that is diagnostically accurate in the evaluation of thyroid function, even in patients with high PBI levels following the administration of iodine-containing compounds. The average serum thyroxine iodine (T4I) level was 5.24[plus or minus]1.06 (1 SD) [mu]g/100 ml in 117 euthyroid subjects, 1.1 [mu]g/100 ml in 51 hypothyroid patients, and 12.9 [mu]g/100 ml in 64 hyperthyroid patients. All but 2 of the hypo-thyroid patients had T4I values that were lower than normal (2 SD). Serum T4I levels were measured in 90 euthyroid patients with high PBI levels due to the administration of KI, Hypaque, Telepaque, Pantopaque, Dionosil, or a combination of these compounds. The average serum T2I level in this iodine-treated group was 5.3 [mu]g/100 ml and 86% of them had normal values.