Surgical removal of insulinoma restores glucose recovery from hypoglycaemia but does not normalize insulin action.
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)
Vigili de Kreutzenberg
S
S
Cattedra di Malattie del Metabolismo, University of Padova, Italy.
Riccio
A
A
Dorella
M
M
Avogaro
A
A
Marescotti
M C
MC
Tiengo
A
A
del Prato
S
S
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*
D001786:Blood Glucose; D007328:Insulin; D013006:Growth Hormone; D005934:Glucagon