Thyrotropin-releasing hormone in geriatric patients: intravenous versus intranasal application

Abstract

The effect of intravenous versus intranasal TRH stimulation was compared in geriatric patients. In patients receiving both iv and nasal tests (N = 35) there was a good correlation between the TSH responses, but in 3 cases the suspicion of inadequate nasal TRH effect arose. The coefficient of correlation of basal to \g=D\TSHwas better in iv tested patients (116 patients in each group, one half having a positive the other half a negative TRH test). In the majority of patients with suspicious incongruity of basal and \g=D\TSH the nasal test was done. The specificity and sensitivity of various basal TSH 'cut-off' points to predict a positive TRH test were better in patients with iv TRH tests (in each group 96 consecutively admitted patients). Insufficiency of the nasal test in geriatric patients is mainly explained by the inability of the old people to aspirate the nasal spray effectively. Besides the advantages of iv TRH application in geriatric patients, the frequency of adverse reactions (14% versus 0%) must be considered. Thus, in a hospitalized geriatric patient, the TRH test should be performed iv in the recumbent position; however, for examination of geriatric outpatients the nasal test is recommended.

Reference Intervals for Serum Thyrotropin: Dependence on the Population Investigated

“…The TRH-test was performed either intravenously (200 ig Antepan-Henning) or, in the minority of the cases, via the nasal route (2 x 1 mg Relefact spray-Hoechst). In 35 patients receiving both intravenous and nasal tests there was a good correlation between the respective TSH responses (Szabolcs et al, 1989). A TSH response > 2.0 mU/i (and basal TSR under 4.0 mU/l) indicated euthyroidism.…”

“…The curve of an ideal diagnostic test would meet at the corner, where both specificity and sensitivity are = 1.0. The cut off point with the maximal Ql is that with the shortest distance from this ideal point (Szabolcs et al, 1989).…”

“…Reference ranges for normal serum thyrotropin (TSH) are usually given either as 95% of the values obtained from healthy euthyroid subjects (Caldwell et al, 1985;Keller, 1986;Ericson et al, 1987;Kaliner et al, 1987), or by the investigation of thyroid patients dividing them according to clinical signs and results of the thyroid tests into hyperthyroid, euthyroid and hypothyroid subgroups and determining the TSH ranges which reliably predict the clinical state (Kailner et al, 1987). TSH, as a screening test for thyroid disorders, has recently been used in other populations, too: in nonselected hospitalized (Ericson et al, 1987;Ronnov-Jessen et al, 1987), geriatric (Brochmann et al, 1988;Szabolcs et al, 1989) and seriously ill (Wehmann et al, 1984;Beyer et al, 1987;John et al, 1987) patients. Different normal ranges for TSH must be suspected in these groups for two reasons: 1/the varying occurrency rate of thyroid disorders, and 2/the interference of other factors (old age, nonthyroid illness, drugs (Snyder and Utiger, 1972;Wehmann et al, 1984;Beyer et al, 1987;Faber et al, 1987;John et al, 1987;Spencer et al, 1987)) influencing TSH release.…”

Clinical implications of biochemical alterations induced by hypothalamic thyrotrophin hormone in elderly people

“…TRH is tripeptide with molecular mass of 362 Daltons, which retains its biological activity given orally, as well as by the nasal and parenteral route (4). Under certain conditions, as well as in elderly people, rectal use is also possible and recommanded.…”