BACKGROUND. Glucocorticoids are first-line drugs for the treatment of amiodarone-induced destructive thyroiditis. Due to the progression of left ventricular dysfunction, recurrence of rhythm disturbances and increased risk of adverse cardiovascular outcomes in this cohort of patients, rapid restoration of euthyroidism, especially in the elderly, is crucial. However, it is not always feasible with the drug therapy, because the time to achieve euthyroidism is unpredictable in each individual case. Identification of factors that allow predicting the efficacy and duration of glucocorticoid therapy will help to determine the correct tactics of patient management.AIM. To identify factors of delayed response to glucocorticoid therapy in patients with type 2 amiodarone-induced thyrotoxicosis.MATERIALS AND METHODS. The study included 11 retrospective and 22 prospective patients aged 30 to 80 years (21 men and 12 women) with verified type 2 amiodarone-induced thyrotoxicosis, who received prednisolone therapy at a starting dose of 30 mg/day. Anamnestic, anthropometric data, results of laboratory and instrumental diagnostics were analyzed. The follow-up period of patients was 1–5 years. The effecasy of therapy was evaluated by the time to achieve euthyroidism, duration of thyrotoxicosis, frequency of repeated waves of destruction and relapses.RESULTS. The average age of the patients was 57.0 [52.0; 66.0] years. After 1 month (30 days) from the start of glucocorticoid therapy, euthyroidism was achieved in 17/33 (51.5%) patients, pfT4GK-fT4GK1month<0.001, pfT3GK-fT3GK1month<0.001. Delayed achievement of euthyroidism (>30 days) was observed in 48.5% of patients. The median time to achieve euthyroidism was 72.0±3.0 (95% CI: 66.1–77.9) days, the average time was 86.9±13.4 (95% CI: 60.6–113.1) days. The median duration of thyrotoxicosis was 120.0±22.1 (95% CI: 76.6—163.4) days, the average time was 137.8±15.6 (95% CI: 107.2–168.4) days. The level of free thyroxine after 30 days of therapy depended on the interval «clinical symptoms — laboratory confirmation» (R2=0.120, p=0.049). Time to achieve euthyroidism depended on age (R2=0.185; p=0.013). Age was also a predictor of repeated waves of destruction (OR=0.833, 95% CI:0.709–0.978; R2=0.428, p=0.025).CONCLUSION. Age is a predictive factor for the time to achieve euthyroidism in type 2 amiodarone-induced thyrotoxicosis.
