title: Surgical removal of insulinoma restores glucose recovery from hypoglycaemia but does not normalize insulin action.
abstract: In the present study we have evaluated the effects of chronic hyperinsulinaemia secondary to insulinoma, on insulin sensitivity and on counter-regulatory responses to hypoglycaemia. We studied six patients (M/F = 3/3; age = 40 +/- years), before and 6-9 months after surgical ablation of the neoplasia, by means of an euglycaemic-hyperinsulinaemic clamp (1 mU kg-1 min-1). Seven normal subjects (M/F = 4/3; age = 38 +/- 6 years) underwent the same experimental study as the control subjects. In insulinoma patients after 100 min of the euglycaemic-hyperinsulinaemic clamp, glycaemia was allowed to drop to a minimum value of 1.9 mmol L-1, and recovery evaluated after interrupting insulin infusion. During the entire study, 3-3H-glucose was infused to determine hepatic glucose production and glucose utilization. Surgical removal of the pancreatic adenoma was followed by a reduction in body weight (BMI = 25.7 +/- 1.9 vs. 23.0 +/- 1.6 kg m-2; P < 0.05), normalization of fasting plasma levels of glucose (2.94 +/- 0.16 vs. 4.83 +/- 0.11 mmol L-1), insulin (162 +/- 24 vs. 48 +/- 12 pmol L-1) and of basal hepatic glucose production (7.6 +/- 0.7 vs. 12.2 +/- 1.11 mumol kg-1 min-1). Before the operation, insulin-mediated glucose disposal was significantly lower than in the controls (30.8 +/- 3.1 vs. 49.1 +/- 3.1 mumol kg-1 min-1). Six to nine months after surgical removal of the adenoma, glucose utilization was unchanged (30.5 +/- 3.3 mumol kg-1 min-1) and still significantly lower than in controls (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Cattedra di Malattie del Metabolismo, University of Padova, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Vigili de Kreutzenberg
authors.forename: A
authors.initials: A
authors.lastname: Riccio
authors.forename: M
authors.initials: M
authors.lastname: Dorella
authors.forename: A
authors.initials: A
authors.lastname: Avogaro
authors.forename: M C
authors.initials: MC
authors.lastname: Marescotti
authors.forename: A
authors.initials: A
authors.lastname: Tiengo
authors.forename: S
authors.initials: S
authors.lastname: del Prato
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D005260:Female; D005934:Glucagon / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D006706:Homeostasis; D006801:Humans; D007003:Hypoglycemia / Q000378:metabolism*; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D007340:Insulinoma / Q000378:metabolism / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000601:surgery*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D013006:Growth Hormone; D005934:Glucagon