Thyroid Hormones in Patients with Clinical Stable Pneumoconiosis

: It is well established that alterations of serum thyroid indices frequently occur in nonthyroid disease. The most common finding is a reduced serum T3 concentration in systemic illness, termed low T3 syndrome. It is considered that this syndrome is a beneficial adaptation to severe illness and reflects the duration and severity of illness. We measured serum thyroid hormones, pulmonary functions, and arterial blood gases in 245 patients (mean: 67.0 years) with clinical stable pneumoconiosis, and investigated the relations of thyroid hormones and other measurements. We also investigated the relation of thyroid hormones and radiographic findings. 1) There was a significant correlation between serum level of free T3 and %VC (p < 0.05), and between serum level of free T3 and FEV1.0 (p < 0.01). 2) There was no apparent correlation between serum level of free T3 and other pulmonary functions (V25/HT, FEV1.0%). 3) There was no apparent correlation between serum level of free T3 and blood gases (PaO2, PaCO2 and A-aDO2). 4) There was no apparent correlation between serum level of free T3 and radiographic findings. 5) Serum levels of free T4 and T4 showed no apparent correlations with other parameters. These results suggest that serum level of free T3 can be helpful to evaluate the clinical severity in patients with pneumoconiosis.