Evaluation of the Growth-Hormone-Releasing Hormone Test in Short Normal and Growth-Hormone-Deficient Children

Abstract

Growth-hormone-releasing hormone (GHRH) tests were performed once [GHRH(1–29)NH₂, 1 µg/kg] or on 2 consecutive days [GHRH(1–44)NH₂, 1 and 2 µg/kg administered in random order] in 27 children with idiopathic, isolated growth hormone (GH)-deficiency and in 49 short normal children, all clinically prepubertal. No differences in GH release were found between the tests performed on the 1 st and 2nd day or according to GHRH dose or sex, both in GH-deficient and control children. 80% of GH-deficient and 87% of control children responded (GH peak > IO ng/ml) to GHRH(1–29)NH₂, and 65% of GH-deficient and all control children to GHRH(1-44)NH₂· No differences in GH release were found between GH-deficient GHRH responders and control children. 17% of GH-deficient and 10% of control children responded only to one of the two tests performed on 2 consecutive days; the lack of responsiveness was unrelated to GHRH dose and sequence of GHRH administration (1st or 2nd day). The GHRH test does not seem to be a reproducible test for the evaluation of GH release, nor is it useful to differentiate GH-deficient GHRH responders from short normal children.

Growth response to growth hormone‐releasing hormone(1–29)‐NH2 compared with growth hormone

“…As noted by others (14)(15)(16), the GH response to intravenous GHRH( 1-29)-NH2 varied widely and was not correlated with height velocity in this group of children. GHRH(1-29)-NH2 given in low doses at 6 months, however, appeared to exert an enhancing effect on GH secretion.…”