BACKGROUND: In patients with insulinoma, biochemical proof of inappropriately elevated insulin secretion during hypoglycemia is required prior to surgery. Because circulating insulin levels usually vary widely, we have used the combined OGTT-fasting test to define new normative criteria for a retrospective systematic analysis. METHODS: We retrospectively analyzed insulin concentrations from OGTT-fasting tests of 64 patients with surgically removed insulinomas. In addition, the response to intravenous somatostatin infusions was estimated. Normative criteria were defined to obtain comparable estimates of insulin concentrations: basal, glucose-stimulated maximum, postglucose plateau, and secretory bursts. RESULTS: Three types of insulin secretion patterns were identified: (1) the autonomous secretion pattern (type 1, N=17) with basal and post-OGTT plateau insulin concentrations of approximately 50 mU/L, suppression after OGTT by 41%, virtual absence of distinctive secretory bursts, and resistance to somatostatin-mediated suppression (25 %); (2) the inadequate suppression pattern (type 2, N=28) with moderately elevated basal and post-OGTT insulin concentrations of approximately 20 mU/L, suppression after OGTT by 73%, absence of secretory bursts, and incomplete somatostatin-induced suppression (56 %); (3) the late-burst secretion pattern (type 3, N=19) with similar basal and post-OGTT insulin concentrations of 17 mU/L, suppression after OGTT by 76%, true insulin bursts of Delta 13+/-11 mU/L (184%), and nearly complete somatostatin-induced suppression by 64%. CONCLUSIONS: By means of a new normative analysis of the combined OGTT-fasting test, three different patterns of insulin secretion can be described in patients with insulinoma: the autonomous secretion type, the inadequate suppression type, and the late-burst secretion type.
BACKGROUND: In patients with insulinoma, biochemical proof of inappropriately elevated insulin secretion during hypoglycemia is required prior to surgery. Because circulating insulin levels usually vary widely, we have used the combined OGTT-fasting test to define new normative criteria for a retrospective systematic analysis. METHODS: We retrospectively analyzed insulin concentrations from OGTT-fasting tests of 64 patients with surgically removed insulinomas. In addition, the response to intravenous somatostatin infusions was estimated. Normative criteria were defined to obtain comparable estimates of insulin concentrations: basal, glucose-stimulated maximum, postglucose plateau, and secretory bursts. RESULTS: Three types of insulin secretion patterns were identified: (1) the autonomous secretion pattern (type 1, N=17) with basal and post-OGTT plateau insulin concentrations of approximately 50 mU/L, suppression after OGTT by 41%, virtual absence of distinctive secretory bursts, and resistance to somatostatin-mediated suppression (25 %); (2) the inadequate suppression pattern (type 2, N=28) with moderately elevated basal and post-OGTT insulin concentrations of approximately 20 mU/L, suppression after OGTT by 73%, absence of secretory bursts, and incomplete somatostatin-induced suppression (56 %); (3) the late-burst secretion pattern (type 3, N=19) with similar basal and post-OGTT insulin concentrations of 17 mU/L, suppression after OGTT by 76%, true insulin bursts of Delta 13+/-11 mU/L (184%), and nearly complete somatostatin-induced suppression by 64%. CONCLUSIONS: By means of a new normative analysis of the combined OGTT-fasting test, three different patterns of insulin secretion can be described in patients with insulinoma: the autonomous secretion type, the inadequate suppression type, and the late-burst secretion type.
Authors: R L Tuttle; N S Gill; W Pugh; J P Lee; B Koeberlein; E E Furth; K S Polonsky; A Naji; M J Birnbaum Journal: Nat Med Date: 2001-10 Impact factor: 53.440
Authors: T Söllner; S W Whiteheart; M Brunner; H Erdjument-Bromage; S Geromanos; P Tempst; J E Rothman Journal: Nature Date: 1993-03-25 Impact factor: 49.962
Authors: M Berger; C Bordi; H J Cüppers; P Berchtold; F A Gries; H Münterfering; R Sailer; H Zimmermann; L Orci Journal: Diabetes Date: 1983-10 Impact factor: 9.461