Therapy of Endemic Goitre: Controlled Study on the Effect of Iodine and Thyroxine

Summary

Two kinds of medical treatment of endemic goitre (400 μg of iodine, n=11, and 150 μg of L-thyroxine, n=12) were compared in a double blind study with a placebo group (n=12) during a period of 12 months and an observation time of three months after cessation of therapy. The means of the neck circumference and of the estimated thyroid volume decreased significantly during treatment in both groups, whereas no significant difference was observed in the placebo group. The results in both therapy groups did not differ significantly from each other. No side effects or symptoms of hyperthyroidism were observed.

During treatment the index of free thyroxine (FT₄I) increased significantly in both the iodine and the thyroxine group and ΔTSH after TRH decreased significantly. Total triiodothyronine (TT₃) did not show significant alterations.

Three months after cessation of therapy in the thyroxine treated group the mean FT₄I dropped into the range before treatment, whereas it remained slightly elevated in the iodine group. In the thyroxine treated group the mean ΔTSH was higher than its value before therapy. After withdrawal of iodine, however, the mean ΔTSH remained decreased for three months.

The study indicates that 400 μg of iodine per day may be at least as effective as a standard dose of 150 μg of thyroxine to treat endemic goitre in an iodine deficient area.

Key-Words:

Therapy of Endemic Goitre - Effect of Iodine Administration - Effect of Thyroxine Administration