Haemoglobin A1C Levels Constantly Below Lower Reference Limit in a Diabetic Patient With Microcytic Anaemia

Abstract

Introduction: Haemoglobin A1C (A1C), as a parameter of long-term glycaemic control, has been adopted to guide diabetic therapy all over the world. However, falsely high or low A1C could be troublesome in daily practice. Case description: A 75-year-old male diabetic patient affected by a reasonably inferred life-long history of microcytic anaemia was found to have abnormally low A1C values in the previous 5 months. Subsequent laboratory assessment with brilliant cresyl blue staining and haemoglobin electrophoresis detected haemoglobin H disease as the underlying cause of both the microcytic anaemia and the disturbed A1C measurement. Discussion: Enhanced erythrocyte destruction such as in haemoglobin H disease could explain a falsely decreased A1C level very well. Upon facing a questionable A1C value, physicians dealing with diabetes should consider the possibility of undiscovered underlying causes rather than too tightly glycaemic control.

Keywords

• haemoglobin a1c
• haemoglobin h disease
• microcytic anaemia
• thalassaemia