lycated hemoglobin (A1C) is the product of non-enzymatic glycation of the N-terminal valine of the hemoglobin beta chain formed at a rate proportional to the intracellular glucose concentration. Red cell intracellular glucose concentration directly reflects extracellular glucose concentration due to the presence of constitutively active glucose channels (GLUT1). Due to the 3-month life span of red blood cells, A1C has been widely used to reflect long-term glycaemic control and has also recently been widely adopted for the diagnosis of type 2 diabetes mellitus. Use of A1C for diabetes diagnosis avoids the need for patient fasting and correlates with microvascu- lar complications at least as well as fasting plasma glucose or the oral glucose tolerance test (OGTT) . It, however, is not widely appreciated that non-glycaemic factors may affect A1C including chronic kidney disease (CKD), gender, age and ethnicit