Circulating endothelial cells are elevated in patients with type 2 diabetes mellitus independently of HbA1c

Aims/hypothesis: Patients with diabetes mellitus are well known to be at high risk for vascular disease. Circulating endothelial cells ( CECs) have been reported to be an ex vivo indicator of vascular injury. We investigated the presence of CECs in the peripheral blood of 25 patients with diabetes mellitus and in nine nondiabetic control donors. Methods: Endothelial cells were isolated from peripheral blood with anti-CD-146 - coated immunomagnetic Dynabeads, and were stained with acridine orange dye and counted by fluorescence microscopy. The cells were also stained for von Willebrand factor and Ulex europaeus lectin 1. Results: Patients with diabetes mellitus had an elevated number of CECs ( mean 69 +/- 30 cells/ ml, range 35 - 126) compared with healthy controls ( mean 10 +/- 5 cells/ ml, range 3 - 18) ( p< 0.001). The increase in CECs did not correlate with the levels of HbA(1)c. Circulating endothelial cell numbers were elevated regardless of glucose levels, suggesting that, even with control of glucose levels, there is increased endothelial cell sloughing. Conclusions: Our study suggests that the higher number of CECs in patients with type 2 diabetes may reflect ongoing vascular injury that is not directly dependent on glucose control.