Insulin and glucose clamp techniques were used to investigate insulin action and insulin secretion during childhood. Preliminary results suggest that growth hormone (GH) therapy leads to changes in glucose, amino acid and insulin responses that are qualitatively similar to those observed during puberty. Furthermore, the insulin resistance normally seen during puberty may be restricted to peripheral glucose metabolism. In patients with Turner's syndrome, data indicate that there is an increase in the glucose-stimulated insulin response which is exaggerated by GH treatment.