The effect of hGH deficiency on the insulin response to glucagon after oral glucose loading

Six children and adolescents (aged from 2 6/12 to 16 years) with isolated hGH deficiency were subjected to a standard oral glucose tolerance test (OGTT) followed by the administration of IV glucagon at 180 mins. Three of them underwent a second test after several months of hGH therapy. Nine patients underwent a separate IV glucagon test and two of these patients had both tests. As controls served 14 endocrinologically normal children and adolescents, who underwent both tests. It was found that the patients with isolated hGH deficiency had lower basal plasma insulin and blood glucose levels and that their insulin response to IV glucagon even after oral glucose preloading was significantly lower than in the control group. This response was partially restored by several months of hGH treatment in the three patients tested. These findings are interpreted as further evidence for an insulinotrophic effect of hGH.