Is examination of fructosamine levels valuable as a diagnostic test for diabetes mellitus?

In order to develop a simple, one-point diagnostic test for diabetes mellitus in a mass population surveys, we measured levels of fructosamine (FRA), one of the glycated proteins. Seven hundred and thirty-eight people had their levels of fasting plasma glucose (FPG), FRA and hemoglobin A1c (HbA1c) examined before taking 75 g oral glucose tolerance tests (OGTT). The results of OGTT distinguished a diabetic group (DM) of 143 from a non-diabetic group (non-DM) of 595 subjects. Since there was a significant correlation between FRA levels and plasma glucose levels 2 h after OGTT (PG-2h), as well as between FPG and PG-2h, a discriminant analysis using FPG and FRA was carried out in order to separate the DM group from the non-DM group. According to this analysis, a positive f, where f = FPG-(mg/dl) + 12.0 FRA(mmol/l) - 150, would determine a subject to be a diabetic. However, the sensitivity of this analysis was only 0.521. It can be concluded that the sensitivity of a simple, one-point determination for diabetes mellitus using measured levels of FRA was insufficient, even by application of discriminant analysis, and that the OGTT is still needed for a diagnostic test for diabetes mellitus in mass population surveys.