Falsely high glycated haemoglobin [HbA1C] because of haemoglobin OSU‐Christiansborg

Glycated haemoglobin (HbA1c) is routinely used to assess the degree of glycaemic control in diabetic patients. We report a case of a 73 year old diabetic woman who had an elevated HbA1c of 13.4%. She was on maximum oral hypoglycaemic agents and was commenced on insulin. However, her HbA1c continued to remain high at 20.4%. Subsequent tests revealed that she had a haemoglobin variant, Haemoglobin Osu‐Christiansborg, causing the falsely high glycated haemoglobin.