Increased transforming growth factor-beta1 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-beta1 (TGF-beta1) 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-beta1 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-beta1 compared with controls. Moreover, we found a positive correlation between TGF-beta1 and rT3 (rs = 0.38, P < 0.01) in the whole group of NTI patients. CONCLUSIONS: Our data seem to confirm the hypothesis that TGF-beta1 could play a role in the pathogenesis of some modifications of thyroid function observed in patients with nonthyroidal illnesses.