Plasma growth hormone response to growth hormone-releasing hexapeptide (GH-RP-6) in children with short stature.

Eighteen children with short stature were evaluated for growth hormone (GH) reserve after pharmacological tests and a single iv injection of GH-RP-6. These children were divided into two groups: 10 were diagnosed as having idiopathic GH deficiency by classical stimulation tests (group A) and the remaining 8 (group B) were considered growth-retarded children with normal GH secretion, following conventional stimulation, but reduced endogenous GH secretion. The results were compared with a group of 12 normal children. As a group, patients in group A showed a lower GH response to GH-RP-6, while patients in group B had a similar response as normal controls. However, on an individual basis, a considerable degree of overlapping in responses among the three groups was evident. These data indicate that, on an individual basis, GH-RP-6 testing is not of diagnostic value in children suspected of having idiopathic GH deficiency.