Cortisol levels and clonidine administration.

Abstract

Sir .—I read with interest the article by Slover et al titled A Comparison of Clonidine and Standard Provocative Agents of Growth Hormone in the March issue of AJDC , 1 in which they showed clonidine to be a more sensitive stimulus for growth hormone release than levodopa or arginine. Previous studies, including ours, 2 have already shown clonidine to be at least as effective as insulin-induced hypoglycemia in inducing growth hormone release. Slover et al reported a significant decrease in cortisol levels after clonidine ingestion in subjects with growth hormone deficiencies and in healthy subjects, but they found no change in corticotropin levels in these patients. We have previously reported a decrease in cortisol levels in prepubertal children following administration of clonidine 2 ; however, in a group of healthy adults 3 we found a decrease of both corticotropin and cortisol concentrations following oral administration of 150 μg of clonidine at