Impaired glucose-induced glucagon suppression after partial pancreatectomy.
BACKGROUND
The glucose-induced decline in glucagon levels is often lost in patients with type 2 diabetes. It is unclear whether this is due to an independent defect in alpha-cell function or secondary to the impairment in insulin secretion. We examined whether a partial pancreatectomy in humans would also impair postchallenge glucagon concentrations and, if so, whether this could be attributed to the reduction in insulin levels.


METHODS
Thirty-six patients with pancreatic tumours or chronic pancreatitis were studied before and after approximately 50% pancreatectomy with a 240-min oral glucose challenge, and the plasma concentrations of glucose, insulin, C-peptide, and glucagon were determined.


RESULTS
Fasting and postchallenge insulin and C-peptide levels were significantly lower after partial pancreatectomy (P < 0.0001). Likewise, fasting glucagon concentrations tended to be lower after the intervention (P = 0.11). Oral glucose ingestion elicited a decline in glucagon concentrations before surgery (P < 0.0001), but this was lost after partial pancreatectomy (P < 0.01 vs. preoperative values). The loss of glucose-induced glucagon suppression was found after both pancreatic head (P < 0.001) and tail (P < 0.05) resection. The glucose-induced changes in glucagon levels were closely correlated to the respective increments in insulin and C-peptide concentrations (P < 0.01).


CONCLUSIONS
The glucose-induced suppression in glucagon levels is lost after a 50% partial pancreatectomy in humans. This suggests that impaired alpha-cell function in patients with type 2 diabetes may also be secondary to reduced beta-cell mass. Alterations in glucagon regulation should be considered as a potential side effect of partial pancreatectomies.
Schrader
Henning
H
Department of Medicine I, St. Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, Bochum, Germany.
Menge
Bjoern A
BA
Breuer
Thomas G K
TG
Ritter
Peter R
PR
Uhl
Waldemar
W
Schmidt
Wolfgang E
WE
Holst
Jens J
JJ
Meier
Juris J
JJ
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000032:analysis; D005260:Female; D005934:Glucagon / Q000097:blood*; D050416:Glucagon-Secreting Cells / Q000502:physiology; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010180:Pancreatectomy
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D005934:Glucagon; D005947:Glucose