Islet amyloid in patients with diabetes due to exocrine pancreatic disorders, type 2 diabetes and non-diabetic patients.

BACKGROUND: Amyloid deposits are a typical finding in in pancreatic islets from patients with type 2 diabetes. Whether this is linked to the pathogenesis of type 2 diabetes is currently unknown. Therefore, we compared the occurrence of islet amyloid in patients with type 2 diabetes, diabetes secondary to pancreatic disorders and non-diabetic individuals. PATIENTS AND METHODS: Pancreatic tissue from 15 non-diabetic patients, 22 patients with type 2 diabetes, and 11 patients with diabetes due to exocrine pancreatic disorders (chronic pancreatitis, pancreatic carcinoma) were stained for insulin, amyloid and apoptosis. beta-cell area, amyloid deposits and beta-cell apoptosis were quantified by morphometric analysis. RESULTS: The proportion of islets containing amyloid deposits was significantly higher in both type 2 diabetes and diabetes due to exocrine pancreatic disorders than in healthy subjects. Islets with both amyloid and apoptosis were observed more frequently in type 2 diabetes and, significantly more so, in diabetes due to exocrine pancreatic disorders. In both diabetic groups, apoptotic ss-cells were found significantly more frequently in islets with more prominent amyloid deposits. CONCLUSIONS: The occurrence of amyloid deposits in both type 2 diabetes and diabetes secondary to exocrine pancreatic disorders suggests that islet amyloid formation is a common feature of diabetes mellitus of different etiologies, and may be associated with a loss of pancreatic ss-cells.