Abstract
INTRODUCTION: 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. PATIENTS AND 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.
Original language | English |
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Journal | Journal of Clinical Endocrinology and Metabolism |
Volume | 94 |
Issue number | 8 |
Pages (from-to) | 2857-63 |
Number of pages | 6 |
ISSN | 0021-972X |
DOIs | |
Publication status | Published - 2009 |