Thyrotropin-Releasing Hormone Stimulation Test in Patients with Pituitary Pathology

Abstract

Objectives: To evaluate the value of the thyrotropin-releasing hormone (TRH) stimulation test in the diagnostic work-up of the thyroid function in patients with pituitary pathology. Methods: To compare the thyrotropin (TSH) response and the absolute and fold changes after TRH administration in 35 patients with pituitary pathology and 26 normal subjects. Results: Nine of the patients and 2 of the normal subjects had a pathological response. No difference in the thyrotropic response to TRH was found either for the actual values, or for the absolute or fold changes of TSH between the groups. Conclusion: The role of the TRH test in the evaluation of thyroid function in patients with pituitary pathology is modest. The best variables for evaluation of the presence of central hypothyroidism are still a free thyroxine estimate combined with an inappropriately low TSH.

GH replacement in adults: interactions with other pituitary hormone deficiencies and replacement therapies

“…However, this may be found in NTI (89), in post-operative patients (90,91), during starvation (92), and in severe primary hypothyroidism (93). The TRH stimulation test is used in the diagnosis of CH (94,95), but its value has been questioned (96,97). In addition, in some early studies, bovine TSH stimulation was considered for the diagnosis of CH (98,99), but its use was terminated due to commonly occurring allergic reactions (100).…”

The Case of Hypopituitarism in Traumatic Brain Injury

“…Isolated secondary hypothyroidism is extremely rare and in these patients, samples should be re-analysed by an alternative assay, and low thyroxine binding globulin (TBG) concentrations and nonthyroidal illness have to be excluded before the final diagnosis (Lamberts et al, 1998). Stimulation with thyrotropin releasing hormone (TRH) has given discrepant results (Franklyn, 1997;Hartoft-Nielsen et al, 2004;Lania et al, 2008). The possible confounding by certain antiepileptic drugs is well-described (Cansu et al, 2006;Isojarvi et al, 2001), inducing a biochemical picture mimicking that of secondary hypothyroidism with decreased peripheral thyroid hormone concentrations and a normal TSH.…”

Diagnosis of subclinical central hypothyroidism in patients with hypothalamic–pituitary disease by Doppler echocardiography

“…In practice, the diagnosis of central hypothyroidism relies on a low serum free thyroxine (FT 4 ) with decreased, normal, or slightly elevated serum TSH (3). However, a low serum FT 4 is a highly specific but insensitive marker of hypothyroidism, whereas several serum markers of thyroid hormone action and the response of TSH to its releasing hormone have shown low diagnostic sensitivity (4,5).…”