| Popis: |
Background: Diabetes UK welcomes the 2011 decision by the WHO to accept the use of HbA1c testing in diagnosing diabetes. HbA1c of 48mmol/mol (6.5%) is recommended as the cut off point for diagnosing diabetes. A value of less than 48mmol/mol (6.5%) does not exclude diabetes diagnosed using other glucose tests. NICE guidelines recommend use of two consecutive high HbA1c in absence of symptoms to diagnose type 2 diabetes. Case report: A 51-year-old female was referred for diabetologist review of her newly diagnosed type 2 diabetes. The diagnosis was made in accordance with the NICE and WHO guidelines, based on two consecutive HbA1c results of 8.1% (65 mmol/mol). Her repeated fasting and postprandial plasma glucose were normal and she has no osmotic symptoms. Her fructosamine was normal. Her oral glucose tolerance test was normal as well. Her anti GAD and anti-islet cell antibodies are negative. The patient’s haematological indices were normal and she was unaware of any family history of hemoglobinopathy. She has family history of type 1 diabetes. After all these normal blood sugar reading, the diagnosis of diabetes was refuted and her treating GP was contacted to erase the diagnosis of type 2 diabetes from her medical record.. She was rejected in more than one occasion as a blood donor due to autoantibodies. We are not aware of any correlation between falsely high HbA1c and the presence of autoantibodies, currently we are investigating that. We are sure during the conference of endo 2019; we will have a clear answer. We are aware of case report from Canada of similar scenario of false positive HbA1c published in 2015(1). Conclusion: 1. We are investigating now the cause of this lady spurious high HbA1c. Whatever cause would be found, this case questions the usefulness of HbA1c as solo in diagnosing type 2 diabetes. Although all the limitations of HbA1c must be addressed but we do not think it is cost effective to rule out all causes of false positive HbA1c before depend on HbA1c in the diagnosis of diabetes type especially in the presence of cheap and well validated other tests like oral glucose tolerance test, plasma fasting and postprandial blood glucose. 2. We recommend that high HbA1c must be confirmed by another well validated way of diabetes diagnosis such as osmotic symptoms or/and abnormal blood sugars readings to confirm the diagnosis of type 2. Reference: 1-Erroneous Diabetes Diagnosis: A Case of HbA1c Interference. Diabetes Care 2015;38:e154-e155. |
