Double Stimulation with Arginine Infusion for Assessment of Growth Hormone in Short Children

Aim: To verify whether the release of GH obtained by double stimulation with arginine (arginine plus arginine) is equal to that obtained using two different stimuli (arginine plus glucagon). Patients: Fifty (50) children (27 M, 23 F), aged 9.54 ± 3.81 yr, 37 prepubertal and 13 at onset of puberty, who were being investigated for growth failure, were divided in two groups. Twenty-two subjects (group A) received arginine infusion followed by glucagon injection as the other provocative stimulus to confirm blunted GH response. Sixteen patients (group B) received arginine infusion as the first provocative stimulus followed by a second infusion of arginine, as they had presented risk factors for the use of glucagon as a second stimulus. Results: No differences in serum GH peak levels were found between group A and group B patients receiving arginine monochloride infusion as first stimulus (4.14 ± 2.43 ng/ml vs. 4.54 ± 1.94 ng/ ml, respectively). Moreover, no differences in serum GH peak concentrations were observed between group A, who received a glucagon injection as the second stimulus, and group B, who received another arginine infusion as the second stimulus (6.17 ± 1.94 ng/ml vs. 5.00 ± 2.00 ng/ml, respectively). Conclusion: Repetition of arginine as a provocative test is as effective as other classical stimuli in evaluating GH secretion. Therefore, it can be used in particular cases where other stimuli may involve risks for the patient.