[Insulin secretion and action in acromegaly].

17 patients with active acromegaly (7 of them had diabetes mellitus, too), 13 patients with type I diabetes mellitus and 20 healthy controls were examined. The residual beta-cell secretion was determined by venous Tolbutamide test and the insulin sensitivity was determined by euglycemic clamp-technique. A positive correlation was found between the growth hormone level and prolactin and the size of the basic insulin secretion. In acromegaly (with or without diabetes) the sensitivity of beta-cell apparatus towards the stimulant Tolbutamide is preserved but the insulin reserves are diminished. There exists a positive correlation between the growth hormone level and the degree of insulin resistance and between the increased prolactin level and the degree of insulin resistance in acromegalic patients.