[Clinical value of the gonadotropic hormone releasing hormone (GHRH) test in the diagnosis of growth deficiency].

Many stimulation tests are available for the assessment of growth hormone release from the pituitary in clinical practice. Three of the most common tests are insulin-hypoglycaemia, arginine stimulation and spontaneous hGH nocturnal peaks and profiles. In this study we compared the Growth hormone releasing-hormone (GHRH)-test in a dose of 1 microgram/kg b.w. with these three other tests for evaluation of the somatotropic function of the pituitary. Each of these four tests was performed in 29 children with short stature due to growth failure of various etiologies and height-deficits (-SDS) of -3.0 +/- 0.5 SE. The peak plasma hGH levels of all patients after GHRH stimulation did not correlate with the respective peak values during insulin (r = 0.02) and arginine (r = 0.28) stimulation and with peak levels during the spontaneous nocturnal hGH profile (r = 0.18). The diagnostic value of the GHRH test alone is thus still questionable in establishing the diagnosis of a hypothalamic GHRH/GH defect, because some of these patients do not react to the first GHRH dose as one might expect, but only after a few days of repeated injections of GHRH (priming). The tolerance of intravenous injections of GHRH was excellent. The mean plasma GH response to GHRH was higher (p less than 0.05) in the group of children with constitutional short stature than in GH deficient patients, but there were overlaps in this group with normal volunteers and other groups of patients with growth failure.