Clinical, laboratory and immunologic effects of the treatment of endemic goiter with T4, T3 and KI.

We treated 204 patients with endemic nontoxic goiter with T4, T3 and KI, singly or in combination. Definitely nodular goiters were excluded, since the possibility of autonomy would be increased. Goiter size was evaluated before and 6 months after treatment clinically in a blind way, i.e. the observer (always the same) did not know either the pretreatment goiter size or the treatment the patient had received. At the same time various laboratory parameters were recorded. All the active treatments (but not placebo) resulted in a highly significant decrease in the gland size. The effectiveness decreased in the following order: 1) T3 50 micrograms/d (most effective), 2) (T4 50 micrograms/d + T3 12.5 micrograms) x 2, 3) T4 150 micrograms + iodide 150 micrograms/d, 4) T4 75 micrograms + T3 18.75 micrograms/d, 5) T4 200 micrograms/d, 6) T3 37.5 micrograms/d, 7) Iodide 300 micrograms/d, 8) T4 150 micrograms/d, 9) Iodide 150 micrograms/d (least effective) and 10) Placebo (not effective). The results show that T4 200 micrograms and T3 50 micrograms are roughly equipotent, and slightly more effective than 300 micrograms of Iodide. Taking into consideration the side effects (increase in pulse rate, shortening of the Achilles tendon reflex) did not change the order of effectiveness in an important way. The clinical outcome correlated in general with the suppression of the 131I uptake (r = 0.220, p = 0.03) and the TRH test (r = 0.248, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

The relation of serum T4 and TSH with the urinary iodine excretion.

The urinary iodine excretion, expressed as the iodine/creatinine (I/Cr) ratio, was correlated with the serum T4 and TSH levels in persons with a relatively constant iodine intake for at least 6 months. It was found that the group with an I/Cr ratio of 151-200 micrograms/g had on average the lowest serum TSH and the highest serum T4 level. The differences in serum TSH from the other groups were statistically significant, whereas the differences in serum T4 were not. It is concluded that an I/Cr ratio of 151-200, corresponding to an iodine intake of about 200 micrograms/day, is associated with the lowest TSH stimulation of the thyroid gland in man and probably represents the optimal conditions for its function.

Treatment of endemic goitre with iodine and thyroid hormones, alone or in combination. (Preliminary report).

108 patients with endemic nontoxic goitre have been treated in the field with thyroxine (T4), triiodothyronine (T3), and potassium iodide (KI), singly or in combination, or with placebo. After 6 months of continuous treatment, goitre size decreased significantly in the 7 actively treated groups, but not in the one treated with placebo. The combination of 150 micrograms T4 + 150 micrograms KI daily seemed the most effective treatment, both clinically and by its suppression of the 131I uptake and the TSH response to TRH, followed by 100 micrograms T4 + 25 micrograms T3 or 200 micrograms T4, but the difference from the other groups was not statistically significant. The increase in the pulse rate (PR) and the shortening of the photomotogram of the Achilles tendon reflex (PMG) were taken as indices of thyrotoxicity and side-effects of the treatment. There was no significant difference in the side-effects between any two of the active groups if effectiveness was also taken into account. The decrease in goitre size was not correlated to either the final serum T3 value achieved at the end of the treatment, or the thyroidal 131I uptake. There was, however, a weak but significant correlation between the decrease in goitre size and the TSH response to TRH. This casts some doubt to the concept that thyroid hormones decrease goitre size solely by suppressing the pituitary TSH release. Of the 30 patients treated with KI singly or in combination and studied in this respect, 8 developed autoantibodies against thyroglobulin and/or the thyroidal microsomal antigen compared to 1 of 22 not receiving KI (P = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)