A falling HbA 1c is not necessarily an indicator of improving diabetes control

Abstract

The finding of a very low haemoglobin A_1c(HbA_1c)(1·4%) in a diabetic patient with fairly high plasma glucose levels prompted haematological investigations, which revealed auto-immune haemolysis and a Hb concentration of 7·7g/L. Following treatment, both Hb and HbA_1c concentrations increased roughly in parallel until, 4 months later, Hb was 13·8g/L, HbA_1c 5·2% and plasma glucose was 6·8mmol/L. This case illustrates that a falling HbA_1c cannot always be attributed to improving glucose control in diabetic patients.