caa a22 4500 465804470 CHVBK 20180323112100.0 cr unu---uuuuu 170327e19900301xx s 000 0 eng 10.1007/BF03349549 doi (NATIONALLICENCE)springer-10.1007/BF03349549 The glucose clamp technique for the study of patients with hypoglycemia: insulin resistance as a feature of insulinoma [Elektronische Daten] [A. Pontiroli, M. Alberetto, F. Capra, G. Pozza] Occurrence of hypoglycemia during a prolonged fasting, accompanied by inappropriately high serum insulin levels, is considered a reliable index of the presence of insulinoma. Previous in vitro studies on insulin receptors, and in vivo hyperinsulinemic clamps have shown that patients with insulinoma are insulin resistant. In the present study 10 patients with insulinoma, 6 patients with nontumoral (also called functional or reactive hypoglycemia) hypoglycemia and 6 normal subjects were fasted for 24 h and their blood glucose levels were maintained constant by means of a programmed glucose infusion (isoglycemic glucose clamp) delivered by an artificial pancreas (Biostator). Blood glucose levels were monitored in continuum, glucose infused (M) and glucose clearance (MCR) were evaluated at hourly intervals, and serum insulin (IRI) levels were evaluated every 6 h. Blood glucose levels were higher in controls than in patients with insulinoma and in patients with non tumoral hypoglycemia; M, MCR and IRI were progressively higher in controls, in patients with nontumoral hypoglycemia and in patients with insulinoma. The M/l index (M divided by IRI levels, an index of insulin sensitivity) was lower in patients with insulinoma than in other subjects and patients, indicating the existence of insulin resistance. These data indicate that: i) patients with insulinoma require large amounts of glucose to remain isoglycemic during a prolonged fast; ii) insulin resistance is a common feature of insulinoma and can be shown even under near physiologic conditions such as a 24-h fasting. The present study does not clarify whether insulin resistance occurs at the hepatic level or at other, peripheral levels. Italian Society of Endocrinology (SIE), 1990 glucose clamp nationallicence insulin nationallicence hypoglycemia nationallicence insulinoma nationallicence artificial pancreas nationallicence insulin resistance nationallicence Pontiroli A. Istituto Scientifico San Raffaele, Cattedra di Clinica Medica, Università degli Studi di Milano, via Olgettina 60, 20132, Milano, Italy aut Alberetto M. Istituto Scientifico San Raffaele, Cattedra di Clinica Medica, Università degli Studi di Milano, via Olgettina 60, 20132, Milano, Italy aut Capra F. Istituto Scientifico San Raffaele, Cattedra di Clinica Medica, Università degli Studi di Milano, via Olgettina 60, 20132, Milano, Italy aut Pozza G. Istituto Scientifico San Raffaele, Cattedra di Clinica Medica, Università degli Studi di Milano, via Olgettina 60, 20132, Milano, Italy aut Journal of Endocrinological Investigation Springer International Publishing 13/3(1990-03-01), 241-245 0391-4097 13:3<241 1990 13 40618 https://doi.org/10.1007/BF03349549 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF03349549 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Pontiroli A. Istituto Scientifico San Raffaele, Cattedra di Clinica Medica, Università degli Studi di Milano, via Olgettina 60, 20132, Milano, Italy aut NATIONALLICENCE 700 1- Alberetto M. Istituto Scientifico San Raffaele, Cattedra di Clinica Medica, Università degli Studi di Milano, via Olgettina 60, 20132, Milano, Italy aut NATIONALLICENCE 700 1- Capra F. Istituto Scientifico San Raffaele, Cattedra di Clinica Medica, Università degli Studi di Milano, via Olgettina 60, 20132, Milano, Italy aut NATIONALLICENCE 700 1- Pozza G. Istituto Scientifico San Raffaele, Cattedra di Clinica Medica, Università degli Studi di Milano, via Olgettina 60, 20132, Milano, Italy aut NATIONALLICENCE 773 0- Journal of Endocrinological Investigation Springer International Publishing 13/3(1990-03-01), 241-245 0391-4097 13:3<241 1990 13 40618 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer