Improved glucose metabolism after subtotal pancreatectomy for pancreatic cancer.

Diabetes occurs frequently in patients with pancreatic cancer. To investigate the impact to tumour removal, seven patients were studied before and after 85 per cent subtotal pancreatectomy for adenocarcinoma of the pancreas. The frequency of diabetes was determined by the oral glucose tolerance test. Fasting levels of C peptide and insulin were measured in plasma, and insulin secretion was investigated by hyperglycaemic glucose clamp and glucagon stimulation. Six of the seven patients were diabetic before surgery and four required insulin treatment. Improvements in diabetic status and glucose metabolism were found in all seven patients after operation, as demonstrated by increased glucose metabolic capacity during hyperglycaemia. This occurred despite a postoperative reduction in insulin secretion and is explained by the observed augmentation of whole-body insulin sensitivity after surgery. A diabetogenic factor may be produced by pancreatic adenocarcinoma that may be responsible, directly or indirectly, for the high frequency of diabetes in patients with pancreatic cancer.