Dose related effects of betamethasone on iodothyronines and thyroid hormone-binding proteins in serum

Abstract

Earlier studies of the effect of glucocorticoids on thyroid function tests have given different results. This may be due to the fact that varying corticosteroid doses were used. Four groups of healthy volunteers, who were given betamethasone in increasing doses (1,5. 3.0, 4.5 and 6.0 mg daily) for 5 days were examined. Definite dose-response relations were found for serum thyroxine and T3 [triiodothyronine] while no clearcut dose-response pattern was found for thyroxine T3. The results obtained explain previous variable results. Oral corticosteroids also affected the concentration of the thyroid hormone-binding proteins but no clearcut dose-response relation were observed.