Endocrine Abstracts

Background: HbA1c remains the most powerful outcome measure for children and young people with diabetes. It is collected at every clinic visit and is used for individualised discussions around diabetes control and for national benchmarking. However, despite DCCT and IFCC standardisation, there is still no overall consensus as to the most appropriate methodology, particularly when assessing patients with haemoglobinopathies that may affect HbA1c measurement.

Objective: To describe the methods of glycaemic monitoring in paediatric diabetes units (PDUs) across England and Wales.

Method: Cross-sectional surveys (electronic/paper) sent to all paediatric diabetes consultants in England and Wales through network coordinators. Data on frequency, timing and HbA1c measuring methods were collected from data submitted to the National Paediatric Diabetes Audit.

Results: 59% (n=101/171) of PDUs responded representing 16 599 patients (96.9% type 1, 1.7% type 2, and 1.4% others). HbA1c methods for 3-monthly follow-up were: capillary point-of-care (POC) testing (n=85), laboratory capillary (Cap lab) (n=7), Cap lab/POC (n=4), and venous laboratory/POC (n=5). HbA1c were taken 95% on the day and 5% before the appointment. 78 units reported local laboratory HbA1c methods: ion-exchange affinity HPLC (n=29), capillary electrophoresis (n=5), immunoassay (n=2), ion-exchange HPLC (n=39), boronic affinity (n=2), and spectrophotometry (n=1). Full blood count was included with laboratory HbA1c regularly in 18/82 and selectively in 10/82. At annual reviews, laboratory venous HbA1c were always measured in 46/82 and selectively in 14/82. Selective screening for haemoglobinopathies was performed in 36/80. Methods of glycaemic monitoring in patients with haematological disorders, reported by 74 units, included, fructosamine (n=51), HbA1c (n=32), glucose pattern (n=32), average glucose (n=30), continuous-glucose (n=29), fasting glucose (n=3), total HbA1c (n=8), glycated protein (n=4), and none (n=2). Only 51/101 of respondents were aware of interferences in the methods affecting the reliability of HbA1c results.

Conclusions: There is considerable variation in the methods of glycaemic monitoring in paediatric diabetic patients nationally and lack of awareness of factors that may impinge on HbA1c results.