Effect of intensive glycaemic control on endothelial progenitor cells in patients with long-standing uncontrolled type 2 diabetes

Abstract

Endothelial progenitor cells (EPCs) have an important role in repair following vascular injury. However, in patients with diabetes, EPC number and function are markedly reduced. It is unclear whether intensive glycaemic control can modify EPC properties in diabetic patients. We aimed to examine whether glycaemic control can improve EPC number and function in patients with long-standing uncontrolled type 2 diabetes. Thirty-five patients with treated type 2 diabetes and HgA1c ≥ 8.5% were included. Patients were tested at baseline and after 3-4 months of an intensive glycaemic control programme, with the aim of achieving HgA1c of 7%. The diabetes group was compared to 20 patients without diabetes (control). Circulating EPC levels were assessed by flow cytometry for expression of VEGFR2, CD133, and CD34. The capacity of the cells to form colony-forming units (CFUs), and their migration and viability were quantified after 1 week of culture. Patients with diabetes (mean age 61.1 ± 7 years, 28.6% women, disease duration of 19.2 ± 8 years) had a baseline HgA1c of 9.4 ± 0.8%. After the glycaemic control period, HgA1c decreased to 8 ± 0.8%. Circulating EPC levels increased significantly after the intensive control period and reached a level similar to the control group. The number of EPC CFUs also increased significantly after glycaemic control but remained lower than the control group. All EPC functional assays improved following the glycaemic control. In patients with uncontrolled long-standing type 2 diabetes, intensive glycaemic control was associated with an increase in the levels of circulating EPCs, and improvement in their functional properties.