Iodine vs thyroxine. A changing concept of therapy in endemic goiter?

The hypothesis that goitrogenesis in iodine deficiency can be attributed to the stimulatory effect of thyrotropin (TSH) on the thyroid gland and has long been held to be valid. The task of this review is to describe the reasons why this concept is being challenged. In addition, we report on the autoregulation of the thyroid gland and on in vitro investigations dealing with TSH as a growth factor, which have yielded conflicting results. Finally, we summarize preliminary studies comparing the therapeutic effect of thyroxine and iodine on goiter size. In comparison to thyroxine, iodine application in doses of 300-500 micrograms/day may represent an equally effective way of treatment in areas of endemic goiter, especially in younger patients. In this age group, the risk of side-effects, e.g., iodine-induced thyrotoxicosis, should be low.