FREE-THYROXINE AND THYROTROPIN LEVELS IN PATIENTS TREATED FOR CUSHINGS-DISEASE

Objective: Determine the frequency and changes in thyroid hormones in Gushing's disease. Methods: Free thyroxin and thyrotropin levels were measured in 11 patients (age range 17 to 60 years) with Gushing's dise ase both before and after resection of the pituitary adenoma. Results: Free thyroxin levels were low (8.3 to 11.7 pmol/l) in 7 patients. The se patients had no clinical manifestations of hypothyroidism. In 4 pat ients, cure of the pituitary adenoma led to normalization of the thyro id hormones 10 days after operation (13 to 55 pmol/l); in the other ca ses surgical cure was unsuccessful and thyroxin levels remained low, C ortisol levels were finally normalized in these patients after irradia tion of the pituitary, a second pituitary operation, or bilateral rese ction of the adrenal glands in 2 patients. Normal thyroxin levels were thus achieved. There was no correlation between serum cortisol and fr ee thyroxin. Conclusion: Thyroid hormones should be assayed regularly in patients with Gushing's disease as a supplementary control of treat ment effectiveness.