Abstract
The hypothalamic-pituitary-testicular function was evaluated in twenty-two male patients with hyperthyroidism. Loss of libido were present in 86.8% and gynecomastia was not observed in any of the cases.
1) Basal plasma LH, FSH, Testosterone and Estradiol levels were significantly higher than in normal men.
2) LH response to LH-RH test was exaggerated in eighteen of the twenty-two patients. FSH response to LH-RH test was normal in eighteen of the twenty-two patients. LH response after treatment became less sensitive than bofore treatment. FSH response after treatment did not change and remained within normal limits.
3) Testosterone response to HCG administration was blunt in ten of the eleven pa-tients. Estradiol response to HCG was exaggerated in six of the ten patients. Testoste-rone response to HCG after treatment became less sensitive than before treatment, but Estradiol response to HCG after treatment did not change significantly.
We concluded that male patients with hyperthyroidism have
1) partial failure of the Leydig cell function and
2) blunt response to the feedback effect of Estradiol.
