[Disturbances of the thyroid function in patients with anorexia nervosa]

There are clinical similarities between anorexia nervosa (AN) and hypothyroidism. Previous reports have shown decreasing fT3, increasing rT3, sporadically decreasing fT4 and normal levels of serum TSH. To asses thyroid function in 36 patients with AN (4 boys, 32 girls, the subjects ages ranged from 12 to 18 years) serum levels of fT4, fT3, rT3, TSH were measured. We examined activation of the hypothalamic - pituitary- thyroid axis by using TRH test (TRH i.v. 0,2 mg, measured TSH at 0', 30', 60', 90') in 30 patients out of this group. 67% (24) patients of the examined group resulted in low level of fT4 (0,75-0,97 ng/dcl), but low decreasing fT3 (=0,67 pg/ml) was only found with 1. The level of rT3 were normal. The level of TSH were low (0,87-0,97 micro IU/ml) in 25% (9) of patients, but 6 of them also manifested low decreasing fT4 (0,87-0,97 ng/dcl). A hyporesponse of TSH to TRH was noted in 17% (5) of patients, a delayed TSH response to TRH was seen only in 1. Thyroidal dysfunction in AN was basically expressed by low decreasing fT4, and also by the disturbances of the TRH-TSH secretion.