Effect of growth hormone on carbohydrate metabolism in hypopituitary dwarfs

Among 15 idiopathic growth-hormonedeficient dwarfs, 8 were found to have diabetic oral glucose tolerance curves. Six with abnormal glucose tolerance tests have received long-term courses of Human Growth Hormone (HGH) (Raben) 1.6 mg. intramuscularly three times a week (t.i.w.). All have demonstrated a good growth response and significant improvement in their glucose tolerance. In three of these children, serum insulin levels prior to therapy were low and increased with HGH administration. Three other hypopituitary dwarfs, in whom HGH therapy has not yet been started, also showed initial low insulin response to oral glucose administration. The observed increase in insulin response with HGH persisted through treatment and, in those children treated more than two years, tended to be normal even after one month's withdrawal of growth hormone. This increased insulin production may be essential in production of growth, since both growth hormone and insulin are required for protein synthesis. The persistence of an improved glucose tolerance and insulin response suggests that besides the acute action of growth hormone in increasing serum insulin levels, it may also have a pancreatrophic effect. (Metabolism 17: No. 1, January, 74–83, 1968)