Thyroid function in acute intermittent porphyria: a neurogenic cause of hyperthyroidism?

Thyroid function was investigated in 17 patients with acute intermittent porphyria (AIP). In 13 patients in remission and latent for the disease, thyroid function was normal. In contrast, transient hyperthyoridism with elevated total T4, T3 free T4 and T3, and FTI levels occurred in one pregnant patient with severe attacks of AIP, and similar, though less pronounced, alterations in thyroid function were found in three other symptomatic female patients. It is suggested that increased thyroidal sympathetic neural stimulation is responsible for these changes in thyroid function.