Decrease in vascular endothelial growth factor expression area in islets may be associated with type 2 diabetes development

Aims: Animal studies have demonstrated that decreased vessel density in islets due to reduced expression of islet vascular endothelial growth factor (VEGF) may lead to impaired insulin secretion from β-cells, possibly contributing to type 2 diabetes development. However, no study has demonstrated an association between VEGF expression and vessel density in islets in human subjects with type 2 diabetes. The aim of this study was to evaluate the role of VEGF expression in islets in type 2 diabetes development, using human pancreatic tissue. Methods: We collected pancreatic tissue at autopsy from type 2 diabetic subjects (n = 13) and age- and sex-matched nondiabetic subjects (n = 13) under 80 years old, and investigated VEGF expression area and vessel density in islets by immunohistochemical staining. Results: In comparison with nondiabetic subjects, type 2 diabetic subjects showed a decrease in both islet VEGF expression area and islet vessel density, which were positively correlated in all subjects examined and in type 2 diabetic subjects. Conclusions: Decreased islet VEGF expression may be associated with the decrease in islet vessel volume, which probably contributes to type 2 diabetes development due to impaired insulin secretion from β-cells.