A comparison of fructosamine and glycosylated haemoglobin measurements at a diabetic clinic.

Fructosamine or glycosylated haemoglobin (HbA1) measurements are most useful in the diabetic clinic if results are available when the patient is seen, with minimum waiting time. Fructosamine measurements have the advantage of being cheaper and faster to perform on large numbers of patients than HbA1 measurements. In order to assess the acceptability of fructosamine as a complete alternative to HbA1, fructosamine, HbA1 and random plasma glucose measurements were made on all patients attending the diabetic clinic for a 6-week period. Either the fructosamine or the HbA1 result was made available when the patient was seen and the other result was given at the end of the clinic for comment as to whether or not it would have altered management. The clinicians indicated that in 7% of cases, the HbA1 result would have altered management if available when the patient was seen, whereas in 2.5% of cases, the fructosamine result would have altered management. The commonest discrepancy was disproportionate elevation of HbA1 with a normal or near normal fructosamine. For the whole group, 32% had a normal fructosamine but only 16% a normal HbA1. The best overall correlation was between HbA1 and glucose (r = 0.67). Fructosamine correlated less well with both HbA1 (r = 0.55) and glucose (r = 0.51). Thus fructosamine was an acceptable alternative to HbA1 in most cases but caution is required, particularly in patients with persistently normal fructosamine results for whom additional HbA1 checks are advised.