[The importance of serum insulin determination in the diagnosis and treatment of diabetes mellitus (author's transl)].

Various types of insulin secretion can be distinguished in diabetics by means of radioimmunological serum insulin determination: Overweight, subclinical diabetics with increased insulin response in the test, adult diabetics with evident insulin response and diabetics with absent insulin response following stimulation. The stimulation or load tests described are an oral glucose tolerance test followed by a sulphonyl urea load test, a "maximum" stimulation test and a glibenclamide-glucose load test. The serum insulin response in these tests is of both diagnostic and prognostic importance to the treatment. By means of serum insulin determination the treatment of diabetes can be set on a rational biochemical basis, and decisions on possibly envisaged modifications of treatment can be facilitated and safeguarded.