Comparative Efficacy and Side Effects of the Treatment of Euthyroid Goiter with Levo-Thyroxine or Triiodothyroacetic Acid

Abstract

Euthyroid goiter is usually treated with TSH-inhibitory doses of levo-T4 (L-T4). Because triiodothyroacetic acid (TRIAC) decreases TSH levels, the following study was perfomed: 36 euthyroid goitrous female patients (no cancer or chronic thyroiditis) were randomized to TRIAC (19.6 μg/kg) (n = 19) or L-T4 (1.7 μg/kg) (n = 17) treatment during 11 months. Goiter volume; lumbar and femoral bone mineral density; serum osteocalcin; deoxypyridinoline; TSH; free T4; total, high-density lipoprotein, and low-density lipoprotein cholesterol; and triglycerides were measured before and after the study period. Student's t test and χ 2 analysis were performed. TSH values (microunits per milliliter) in the TRIAC and L-T4 groups were: 1.91 ± 0.6 (basal) and 0.180 ± 0.1 (after) and 2.1 ± 2.5 (basal) and 0.180 ± 0.3 (after), respectively. Thyroid volume decreased 37.9 ± 35.4% in the TRIAC patients and 14.5 ± 39.5% in the L-T4 group (P = 0.069). Forty-two percent of the goiters with TRIAC reduced more than 50% their initial volume vs. 17.7% with L-T4 (P = 0.15). With TRIAC, patients experienced fewer side ef- fects. No differences in the changes of bone mineral density, serum deoxypyridinoline, osteocalcin, or the lipid profile were observed between both groups. The present results show that TRIAC is more effective than L-T4 in the reduction of goiter size, with comparable effects on peripheral parameters.