Can plasma fructosamine substitute for glycated haemoglobin (HbA1c) estimation in the assessment of diabetic control?

The 'gold standard' marker of overall glycaemic control in diabetes mellitus is the level of glycated haemoglobin (HbA1c). It is, however, an expensive and technically difficult assay and is rarely appropriate to tropical laboratories. Plasma fructosamine measurement is cheaper and easier, though it reflects shorter-term glycaemia. We have measured both indices of control in a group of 154 diabetic patients. There was close correlation between the two measurements (r = 0.6506, P < 0.001), but many patients with abnormal HbA1c levels had normal fructosamine levels. This resulted in an assay sensitivity (compared with HbA1c as gold standard) of only 30%, though specificity was 98%. We conclude that fructosamine measurement cannot be regarded as a substitute for HbA1c determination.