Attempts were made to estimate the response pattern of thyrotrophin (TSH) to thyrotrophin-releasing hormone (TRH) and the optimum time of blood sampling in patients with sporadic euthyroid goitre. Of the 65 subjects studied, 21 served as a reference group and 44 were patients with sporadic euthyroid goitres, divided into diagnostic subgroups according to type of goitre. Patients with a single autonomous thyroid adenoma were excluded. The classification of goitre was based on clinical features, thyroid function tests, thyroid imaging studies using 99mTc pertechnetate uptake, and examination of thyroid specimens originating from selective goitre resection carried out after the laboratory investigations. A standardized i.v. TRH test was performed in all probands and the TSH response was followed for 60 min postinjection. There was a definite trend towards lack of response with increasing nodularity of the thyroid gland. Moreover, no further information concerning the TSH response pattern was achieved by extending the blood sampling period beyond the +20 min limit of the time axis. The study lends support to the view that increasing functional autonomy is a general trend in goitre evolution.

Adult↗

PubMed1978

Effect of selective goitre resection on absent thyrotrophin response to thyrotrophin releasing hormone in idiopathic euthyroid goitres.

Absent thyrotrophin (TSH) response to thyrotrophin releasing hormone (TRH) was found in ten of fifty consecutive nodular goitrous patients who were clinically and biochemically euthyroid. These ten patients together with a reference group engaging fifty-eight healthy individuals matched for sex, age, and geographic region form the basis of the present study. Patients with autonomously functioning single adenomata were excluded from the investigation. In the patient group, values of serum thyroxine (T4), free T4-index, and serum TSH did not differ significantly from those recorded in the reference group, whereas serum triiodothyronine was found to be significantly higher in the patients, although within the normal range. After selective resection of the goitre, the TSH responsiveness to TRH recovered completely. Routine indices of thyroid function, however, demonstrated no major deviation from pre-operative levels. During a follow-up period of 1 year, no systematic alterations were recorded in TSH response to TRH nor in the thyroid function tests, indicating maintenance of euthyroidism with restored normality within the pituitary-thyroid axis. The present study lends support to the view that increasing functional autonomy apparently is a common trend in goitre evolution in a non-endemic area.

Adult↗

PubMed1978