Growth hormone release in hypertensive adolescents treated with clonidine

The release of the growth hormone in the basal state and in response to strenuous exercise was studied in a group of 15 hypertensive adolescents receiving clonidine therapy and in a control group of 17 untreated adolescents of which ten were hypertensive volunteers and seven were health normotensive volunteers. Mean basal growth hormone in clonidine-treated adolescents was 2.8 +/- 0.50 S.E.M. ng/ml, compared to 2.7 +/- 0.48 ng/ml in untreated adolescents. Following exercise stimulation, mean growth hormone was 14.8 +/- 3..1 S.E.M. ng/ml in the treated group and 13.5 +/- 2.8 ng/ml in the untreated group. Growth hormone release is regulated by alpha-adrenergic receptor stimulation. Clonidine acts centrally by alpha-adrenergic stimulation. However, this study demonstrates no effect of chronic clonidine therapy on growth hormone release.