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

Objective: To study transforming growth factor-beta 1 (TGF-beta 1) plasma concentrations in elderly patients with nonthyroidal illnesses (NTI). Design: Case-control study. Methods: We measured plasma concentrations of tri-iodothyronine (T-3), reverse T-3 (rT(3)), thyroxine (T-4), free T-3 (fT(3)) and free T-4 (fT(4)) estimates, TSH, and TGF-beta 1 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 T-3 and fT(3) levels comparable to those in controls; Group B, subjects (30 patients) with T-3 and fT(3) levels lower than controls but rT(3) levels comparable to those of controls; Group C, subjects (10 patients) with T-3 and fT(3) levels lower than those of controls and higher rT(3) levels. The patients of Group C showed higher plasma levels of TGF-PI compared with controls. Moreover, we found a positive correlation between TGF-beta 1 and rT(3) (r(s) = 0.38, P < 0.01) in the whole group of NTI patients. Conclusions: Our data seem to confirm the hypothesis that TGF-beta 1 could play a role in the pathogenesis of some modifications of thyroid function observed in patients with nonthyroidal illnesses.