[Effect of the beta-2 mimetic drug terbutaline of growth hormone secretion in prepubertal asthmatic children].

Asthmatics display a tendency to retarded growth and hyposomia in childhood. The reasons for this are not yet clear, although the atopic disposition seems to occupy a key role. It is a known fact that stimulation of the beta-2 receptors results in inhibiting growth hormone secretion. The purpose of our study was to find out whether the beta-2 mimetic terbutalin, often used in asthma therapy, exercises a negative influence on the spontaneous release of growth hormone in children suffering from asthma. The growth hormone release was studied in 10 prepuberal children suffering from atopic asthma who received intravenous therapeutic doses of terbutalin: testing was done for a total period of 24 hours before and during administration. Terbutalin effected significant inhibition of growth hormone secretion merely during the waking phase (6.2 +/- 1.0 to 3.7 +/- 0.7 ng/ml), but not during the sleep phase (13.1 +/- 1.8 to 12.5 +/- 2.0 ng/ml) and the 24-hour period (11.0 +/- 1.0 to 9.8 +/- 1.5 ng/ml). There was also no significant influence on the average group value for the maximum growth hormone peak (40.8 +/- 9.5 to 42.7 +/- 11.0 ng/ml). These results point to a short-term inhibition of growth hormone secretion, exercised by intravenously administered terbutalin. Terbutalin does not seem to be responsible for any clinically relevant inhibition of growth and development.