Exaggerated TSH responses to TRH in patients with goiter and 'normal' basal TSH levels.

The availability of sensitive thyrotropin (TSH) assays decreased the diagnostic value of thyrotropin-releasing hormone stimulation tests (TRH-ST) in subclinical hypothyroidism. In this study we aimed to evaluate the relation between basal and stimulated serum TSH levels on TRH-ST and to determine the prevalence of patients with normal basal serum TSH and exaggerated TSH responses. 179 patients (117 girls, 123 pubertal) with a median age of 12 (2.7-21.4) years who presented with goiter were enrolled and evaluated for their pubertal stage, height, thyroid autoimmunity, ultrasonography, thyroid function, and TRH-ST. Serum TSH concentrations were determined by sensitive assays. At TRH-ST, a peak serum TSH level >25 mIU/l was considered as an exaggerated response. 30 (17%) patients had an exaggerated TSH response. In patients with serum TSH levels between 2 and 4.68 mIU/l (upper half the normal range), an exaggerated TSH response was observed in 19.5%. A positive correlation between basal and TRH-stimulated TSH levels was determined (r = 0.536, p < 0.01). In patients with an exaggerated TSH response, 23 had normal (discordant) and 7 had high basal TSH levels (concordant). The mean basal serum TSH level was lower in the discordant group compared to the concordant group (p < 0.01). Basal serum TSH levels might not be sufficient for diagnosing subclinical hypothyroidism. Stimulated TSH levels on TRH-ST are valuable, especially when serum TSH concentrations are in the upper half of the normal range.

Evliyaoğlu O ，Berberoğlu M ，Ocal G ，Adiyaman P ，Aycan Z ... -  《hormone research》

Sub-biochemical hypothyroidism: an exaggerated thyroid stimulating hormone response to thyrotrophin releasing hormone.

Sheth JJ ，Thakore PB ，Trivedi BB ，Shah NN ，Vaidya RA ... -  《-》

Comparison between TRH-stimulated TSH and basal TSH measurement by a commercial immunoradiometric assay in the management of thyroid disease.

De Rosa G ，Testa A ，Giacomini D ，Carrozza C ，Maussier ML ，Valenza V ，D'Errico GF ... -  《-》

Thyroid-stimulating hormone, prolactin, and growth hormone response to thyrotropin-releasing hormone in treated children with congenital hypothyroidism.

Sack J ，Shafrir Y ，Urbach D ，Amado O ... -  《PEDIATRIC RESEARCH》

The combined pituitary function test in children: an evaluation of the clinical usefulness of TRH and LHRH stimulation tests through a retrospective analysis of one hundred and twenty six cases.

Westwood ME ，Butler GE ，McLellan AC ，Barth JH ... -  《-》