INCREASED PLASMA-LEVELS OF ENDOTHELIN-1 IN PATIENTS WITH HYPERTHYROIDISM

Plasma concentrations of endothelin-1 (ET-1) were measured in 25 hyper thyroid subjects, 15 hypothyroid subjects, and 21 age-matched normal c ontrols. In hyperthyroid patients, plasma concentrations of ET-1 were significantly higher than in the control group (P < .0001) and in hypo thyroid patients (P < .0001). In contrast, no differences were found b etween hypothyroid patients and controls. Plasma levels of ET-1 were s imilarly elevated as in patients with Graves' disease and those with t oxic adenoma. No correlations were found between plasma ET-1 levels, t hyroid hormones, and thyrotropin (TSH) in hyperthyroid, hypothyroid, a nd euthyroid groups. The results of our study clearly indicate that in hyperthyroidism, circulating levels of ET-1 are strongly increased, a lthough the pathogenesis of the increase is unclear. Copyright (C) 199 5 by W.B. Saunders Company