Oral clonidine: an effective provocative test of growth hormone release.

The authors tested the efficiency of clonidine as a stimulant for growth hormone (GH) release in a group of 31 undersized children aged from four to fourteen years. The efficacy of clonidine was compared with insulin-induced hypoglycaemia, which has so far been considered the most valid test for somatotropic function measurement. The average GH peak after clonidine was 13.7 +/- 1.9 ng/ml, while after insulin it was only 7.0 +/- 0.9 ng/ml. The number of patients responding to clonidine and insulin reacting with GH values below 5, between 5 and 8, and higher than 8 ng/ml were reported, and the difference between the two sets of values was found to be statistically significant (p less than 0,01) in favour of clonidine.