Falsely Low Hba1c in a Patient with Elevated Blood Glucose Levels: Diagnostic Challenges in Hemoglobinopathies: A Case Report

Glycated haemoglobin (HbA1c) is commonly used to assess long-term glycaemic control in patients with diabetes mellitus; however, red blood cell survival and haemoglobin variation affects the accuracy of glycated haemoglobin (HbA1c). We present a middle-aged man with a duration of four-year history of type 2 diabetes mellitus who was admitted for left lower limb cellulitis. Although insulin therapy had to be given to manage persistently elevated blood glucose levels, the HbA1c was unusually low at 4.6%. This discrepancy prompted further investigations. Peripheral blood smear revealed microcytic hypochromic anemia with anisopoikilocytosis and associated iron and folate deficiencies. High-performance liquid chromatography demonstrated reduced hemoglobin A, elevated haemoglobin A₂, increased fetal haemoglobin, and abnormal hemoglobin fractions suggestive of an underlying hemoglobinopathy..