Serum Free Thyroid Hormones are Decreased by Betamethasone Treatment in Graves' Disease

Abstract

38 patients with Graves' disease were treated at random with the glucocorticosteroid betamethasone or with placebo. The daily oral dose was 6.0 mg for the first 5 days, 4.5 mg for the following week, and then 3.0 mg. The serum free triiodothyronine (FT3) concentration decreased within 5 days, while the free thyroxine (FT4) level was reduced first after 3 weeks of betamethasone treatment. The suppressed serum thyrotropin concentration did not change. In the placebo group no significant constant alterations were found in any of the variables studied. The results corroborate that betamethasone decreases FT3 and to a less degree also FT4, which earlier has been indicated by indirect methods, although the mechanisms behind the changes remain to be clarified. Since FT3 is more readily available for the metabolic effects in tissues the rapid striking fall in its concentration is an argument for glucocorticoid treatment in selected patients with severe hyperthyroidism of Graves' disease.

Qualitative and Quantitative Impact of Protective Glucocorticoid Therapy on the Effective 131I Half-Life in Radioiodine Therapy for Graves Disease

“…The pred1 group was further subdivided into low-prednisolone (pred low , 0.5 mg/kg; 72 patients) and highprednisolone (pred high , $1 mg/kg; 53 patients) groups. At RIT, 113 patients were diagnosed with euthyroidism because of antithyroid medication, 106 with subclinical hyperthyroidism (thyroid-simulating hormone [TSH] suppressed, free triiodothyronine [fT 3 ] and free levothyroxine [fT 4 ] levels within reference range), and 52 with thyrotoxicosis (TSH suppressed, fT 3 or fT 4 levels elevated). Because of the effects of antithyroidal drugs, 20 patients presented with subclinical (TSH elevated, fT 3 and fT 4 levels within reference range) and 24 with overt (TSH elevated, fT 3 or fT 4 levels reduced) hypothyroidism.…”

“…In patients already presenting with EO-related symptoms, doses of 1.0-1.5 mg/kg are suggested. Although prednisolone has beneficial effects on the development or course of EO during RIT of GD, it is well established that glucocorticoids themselves change thyroid metabolism and triiodothyronine (T 3 ) and levothyroxine (T 4 ) levels and modulate the concentration of stimulating antithyroid antibodies (thyroid-stimulating hormone receptor antibody [TRAb]) (4)(5)(6)(7). Therefore, the aim of our study was to investigate the influence of prednisolone on the thyroidal 131 I half-life in RIT of GD patients and to assess this effect in comparison to other factors already known to change effective 131 I half-life during the course of RIT in GD patients-namely the thyroidal metabolic state, antithyroid medication, and TRAb level (8)(9)(10)(11)(12).…”

Glucocorticoids do not influence the effect of radioiodine therapy in Graves’ disease

“…Gamstedt et al (13) found that a high dose of betamethasone for 3 weeks resulted in a nearly halving of the 24-h 131 I thyroid uptake in patients with Graves' disease, but this may have been due to a lower activity of the disease, since a significant decrease of the thyroid hormones was seen as well.…”

Einfluss der Glukokortikoidtherapie auf die intratherapeutische Bio distribution von 131I bei der Radio jodtherapie des Morbus Basedow

“…Der Einfluss von Glukokortikoiden auf die Biokinetik von 131 I im Rahmen einer Radiojodtherapie bei Patienten mit Morbus Basedow war bereits Inhalt verschiedener internationaler Untersuchungen (6,8,13,15). Die Vergleichbarkeit der verschiedenen Studien zu diesem Thema wird jedoch dadurch eingeschränkt, dass die Therapieschemata bezüglich Radiojod-und Glukokortikoidtherapie mitunter stark voneinander abweichen.…”

“…Gamstedt et al zeigten 1991 ein verschlechtertes Outcome der Radiojodtherapie des Morbus Basedow unter dem Einfluss von Glukokortikoiden (9). Obwohl 1991 keine signifikante Veränderung des 131 I-Uptakes festgestellt werden konnte, führten die Autoren den geringeren Therapieerfolg auf eine Verminderung der thyreoidalen 131 I-Speicherung unter Glukokortikoiden zurück, die sie 1988 in einer anderen Studie aufzeigen konnten (8). In dieser zeigte sich eine signifikante Reduktion des durchschnittlichen 131 I-Uptakes im 24h-Uptake-Test von 63 % auf 37 % (8).…”