[Radioimmunological determination of insulin in patients with manifest diabetes mellitus as a guide for the planning of therapy (author's transl)].

Intravenous glucose tolerance test followed by combined intravenous glucose-glibenclamid tolerance test were performed to differentiate between sulfonylurea-dependent and insulin-dependent diabetics. As a criterion of sufficient sulfonylurea-induced insulin secretion the extent of the difference of the insulin secretion between both tests was taken. If the difference is more than 600/muE/h insulin treatment seems not to be necessary and oral treatment with sulfonylurea derivates seems to be successful. In comparison with the clinical course of 55 patients the criterion was right in 50 cases. 5 patients could not be classified by the clinical course. Their more-secretion of insulin was in between 200 and 550 muE/mlhour.