[Does hyperthyroidism occur in acute intermittent porphyria?].
During an attack of acute intermittent porphyria clinical signs appear characteristic of hyperthyroidism. For assessing thyroid function in 40 patients with this type of porphyria (22 during attack and 18 during remission) the determinations were done of serum triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH) by radioimmunoassay, calculating also the index of free thyroxine (IFT4) by means of the test of resin T3 uptake. During the attack of porphyria the mean T4 level was increased (p less than 0.05), normal T3 and TSH values were normal, and IFT4 level non-significantly decreased. These results suggest raised level of thyroxine-transporting protein. During remission the levels of T3 and T4 were within normal range, but TSH level was raised without statistical significance, while the level of IFT4 was significantly decreased (p less than 0.01). The results of the investigations suggest the conclusions that in this type of porphyria no hyperthyroidism is present during porphyria attack and in remission.