The cause of nontoxic diffuse goiter and female predominance is not completely understood. The aim of this study was to evaluate the sex-related neuroendocrinological influences on THR stimulation. Neuroendocrine differences might have a role in goiter development with female predominance. Nine men and nine women, a total of 18 patients with nontoxic diffuse goiter were studied. These patients were treated with 200 micrograms of TRH and the effect of gender on the TSH and PRL response was studied. The same procedure was repeated after three days of ethynil astradoil administtion (0.01 mg/day) and following and hopur of somatostatin infusion (250 microgram). The PRL response to TRH in all conditions was greater in women than in men (p<0.05). The mean bas serum TSH value in men treated with ethynil estradoil was significiantly lower in male patients as compared with the men administered only TRH (p<0.05).
The results indicated that: 1) The responses to the TRH stimulation in carious medications are different in both sexes. 2) Ethynil estradiol medication leads to an increase in the bsal TSH value of men .3) Somatostatin suppression on the TSH response to TRH is prominent in male subjects. 4) The lower prevalence of nontoxic goiter in mles seems to be affected by gender and sex steroids and the neuroendocrinological aspects of thissubject might be important
Keywords: TRH test,Somatostatin, Prolactin, TRH, Gender