STUDY ON THYROID-FUNCTION IN ACROMEGALIC PATIENTS TREATED WITH SOMATOSTATIN

Thyroid hormones and TSH release following TRH stimulation was explore d in seven acromegalic patients before and after two weeks of somatost atin administration. Using an ultrasensitive method of TSH measurement (IRMA) basal TSH levels of acromegalic patients were significantly (P < 0.01) lower than the TSH levels of normal controls. TSH release fol lowing TRH stimulation was qualitatively normal in two groups. In addi tion, both the total and free concentration of thyroxine was significa ntly (P < 0.01) lower compared to normal control subjects as well as t he free concentration of triiodothyronine. Finally, somatostatin was a ble to decrease basal GH levels but not plasma TSH concentration in ou r acromegalic patients. These findings might indicate that low plasma TSH levels in acromegalic patients might be expression of mechanic pre ssure induced by the pituitary adenoma.