Effect of growth hormone treatment on insulin secretion and glucose metabolism in prepubertal boys with short stature.

The purpose of this study was to evaluate the effect on insulin secretion and glucose metabolism of daily growth hormone (GH) treatment, 0.1 U/kg, for up to 3 years in 42 short prepubertal boys without GH deficiency. Their median height standard deviation (SD) score increased from -2.7 to -1.7, whereas their weight for height SD score was unchanged after 3 years of treatment. Fasting plasma glucose concentrations were unchanged, but median fasting insulin concentrations increased from 6.0 mU/l before treatment to 7.8 mU/l (p < 0.05) after the first year. No further increase was seen during the second or third years. The median insulin area under the curve 10-60 min after an intravenous glucose tolerance test increased from 480 mU.l-1.min-1 before treatment to 799 mU.l-1.min-1 (p < 0.05) after 1 year. The median glucose disposal rate (K value) before GH treatment, 2.2%/min, was unchanged after 1 year of treatment. A significant positive correlation was found between the change in the height SD score and the change in fasting insulin concentration during the first (r = 0.45; p < 0.01) and second (r = 0.56; p < 0.05) years of GH treatment. It was concluded that GH treatment in prepubertal children without GH deficiency caused a moderate increase in fasting and stimulated insulin concentrations during the first year of treatment. There was no further change during the following years of treatment, and there were no negative effects on fasting plasma glucose concentrations or glucose disposal rates. The increase in insulin concentration was related positively to the growth response.