Objective: To investigate glucose metabolism and insulin secretion on patients with pancreatic cancer compared with healthy control subjects.
Design: Open study.
Setting: Linköping University Hospital, Sweden.
Subjects: 44 consecutive patients referred for radical operations for pancreatic carcinoma, and eight healthy age and sex matched volunteers.
Interventions: Hyperglycaemic glucose clamp in 36 of patients and all volunteers.
Main outcome measures: Glucose tolerance according to WHO criteria, plasma insulin and C-peptide concentrations, and insulin secretion measurements both during hyperglycaemia and after stimulation by glucagon.
Results: Thirty-three patients (75%) had either impaired glucose tolerance or diabetes. Fasting insulin concentrations were raised in the non-insulin-requiring diabetic patients, but similar in the insulin-requiring group compared with healthy control subjects and patients with normal glucose tolerance. In neither diabetic group was insulin secretion affected during hyperglycaemia. After stimulation with glucagon, insulin secretion increased in non-insulin-requiring diabetic patients but remained unchanged in those who required insulin. Glucose metabolic capacity and whole body insulin sensitivity were reduced in patients with diabetes and with impaired glucose tolerance, and the reduction was more pronounced in diabetic patients.
Conclusions: There is a high incidence of impaired glucose tolerance and diabetes in patients with pancreatic cancer, which cannot be explained by impaired secretion of insulin. Other factors that reduce insulin sensitivity seem to have a role in the development of diabetes in this group of patients.