Background: Arginine HCl infusion is commonly used in the diagnostic workup of GH deficiency. There is a paucity of data whether obesity and/or short stature modulate arginine plasma concentration and associated arginine-stimulated GH secretion following a weight-based arginine infusion protocol.
Objective and hypotheses: To study whether auxiological parameters modulate the arginine plasma concentration profile and associated GH secretion in children undergoing arginine stimulation testing.
Method: Retrospective analysis, including 35 short-statured children (24 male; age 10.1±3.5 years; height SDS −3.1±0.6, weight SDS −2.5±1.0; BMI SDS −0.81±0.2). Arginine plasma concentration profile, following intravenous infusion of 0.5 g/kg arginine, was measured using a lithium high-resolution column (Biochrom 30 amino acid analyser); hGH concentration was measured by a highly sensitive ELISA (Mediagnost, Germany).
Results: Peak arginine plasma concentrations were observed 30 min (4980±364 γmol/l) after start of arginine infusion and preceded peak GH concentration (7.5±1.0 ng/ml) at 45 min. Peak arginine plasma concentration correlated both with weight (r=0.464; P<0.01) and height SDS (r=0.407; P<0.05). We found no sex-dependant differences in arginine profile or stimulated GH secretion. In linear regression analyses, weight SDS contributed significantly to the variance in peak arginine concentration (r2=0.13). Furthermore, BMI SDS contributed significantly to the observed variance in peak GH concentration (r2=0.14).
Conclusion: Weight and height are associated with the arginine plasma profile and the stimulated GH response to arginine stimulation testing and thus should be considered in the interpretation of test results.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology