Increased transforming growth factor-β1 plasma concentration is associated with high plasma 3,3',5'-tri-iodothyronine in elderly patients with nonthyroidal illnesses

Abstract

Objective: To study transforming growth factor-β1 (TGF-β1) plasma concentrations in elderly patients with nonthyroidal illnesses (NTI). Design: Case-control study. Methods: We measured plasma concentrations of tri- iodothyronine (T3), reverse T3 (rT3), thyroxine (T4), free T3 (fT3) and free T4 (fT4) estimates, TSH, and TGF-β1 in 48 elderly NTI patients consecutively admitted in our Division of Internal Medicine and Metabolic Diseases, and in 11 healthy age- and sex-matched controls. Results: The data on thyroid hormones enabled us to identify three groups: Group A, subjects (8 patients) with T3 and fT3 levels comparable to those in controls; Group B, subjects (30 patients) with T3 and fT3 levels lower than controls but rT3 levels comparable to those of controls; Group C, subjects (10 patients) with T3 and fT3 levels lower than those of controls and higher rT3 levels. The patients of Group C showed higher plasma levels of TGF-β1 compared with controls. Moreover, we found a positive correlation between TGF-β1 and rT3 (r(s) = 0.38, P < 0.01) in the whole group of NTI patients. Conclusions: Our data seem to confirm the hypothesis that TGF-β1 could play a role in the pathogenesis of some modifications of thyroid function observed in patients with nonthyroidal illnesses.