Dialysis patients suffer from many problems with blood vessels and this is even more so for patients with the added complication of diabetes. Diabetics have a number of reasons for vascular disease and one of the new areas of research is looking at the cells that line the blood vessels, called endothelial cells. It is thought that the number of red blood cells in the blood (haemoglobin concentration) affects the function of these cells. There is very little information available on what haemoglobin level is best for dialysis patients. As diabetics account for almost 40% of dialysis patients worldwide it is important to understand the effect different haemoglobin levels will have on the blood vessels.