L-Dopa Is a Potent Stimulator of Cortisol in Short Children

• Published in: Hormone research in paediatrics Vol. 81; no. 6; pp. 386 - 390
• Main Authors: Marakaki, C., Papadimitriou, D.T., Papadopoulou, A., Fretzayas, A., Papadimitriou, A.
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01.01.2014
• Subjects: Adolescent; Child; Child, Preschool; Dwarfism - diagnosis; Female; Growth Disorders - diagnosis; Human Growth Hormone - deficiency; Humans; Hydrocortisone - blood; Hydrocortisone - secretion; Infant; Levodopa; Male; Original Paper; Short stature; L -Dopa test; Cortisol; Dopamine; Glucagon test
• ISSN: 1663-2818; 1663-2826
• DOI: 10.1159/000357268

Aims: In this study, we evaluated the diagnostic usefulness of oral L -dopa as a stimulatory agent for cortisol. Methods: In 27 short children that were evaluated for possible growth hormone deficiency (GHD), the levels of serum GH and cortisol were determined after oral L -dopa administration and after i.m. glucagon administration. We defined cortisol concentrations >18 μg/dl (496 nmol/l) as adequate response. Peak GH concentration <10 ng/ml in both tests defined GHD. Results: Twenty-five out of the 27 children (93%) studied showed a normal cortisol response, i.e. a peak serum cortisol >18 μg/dl in the L -dopa test, whereas 19 children (70%) had a normal cortisol response after stimulation with glucagon. In the children with normal cortisol response in both tests, the mean peak serum cortisol concentration was 28.7 (SD 1.59) after L -dopa and 26.65 (SD 1.26) μg/dl after glucagon administration. There was no statistically significant difference in peak serum cortisol response to L -dopa between GH-deficient and GH-sufficient children [25.90 (SD 4.9) vs. 29.87 (SD 9.9) μg/dl, respectively]. Conclusions: These results clearly suggest that L -dopa administration is a potent stimulus for cortisol secretion at least in short children.