Background
: With respect to the risk of developing diabetic vascular complications, the central purpose of most screening and detection program is to identify people with diabetes at early stage so they might have adventages of early treatment to prevent complication of the disease. Oral glucose tolence test(OGTT) is widely used for diagnosis of diabetes and impaired glucose tolence, but the performance of a complete OGTT is not only time consuming and expensive but physically demanding on the individual being tested. Determination of HbA₁c and more recently of glycosylated total serum proteins(fructosamine) has been proposed as an alternative method of screening and diagnosis. The aim of our cross-sectional study is to compare the values of fructosamine and HbA₁c for the purpose of diabetes diagnosis with the OGTT as reference method.

Methods : in this study, from January 1996 to August 1996, we included 55 consecutive subjects in Kyeungsang Hospital. Blood samples for HbA₁c and fructosamine determination were drawn at the same time as a fasting plasma glucose sample, and then all subjects underwent a standard 2-hour OGTT according to the World Health Organization recommendations. The subjects were classified according to the American Diabetes Association classification.

Results : In our study, we observed fasting plasma glucose of 145.32±75.00mg/㎗, two-hour plasma glucose of 245.83±155.22mg/㎗, HbA₁c of 7.06±2.77%, and fructosamine of 308.77±128.23㎛ol/ℓ. The correlation coefficient between FPG and HbA₁c was 0.9098(p<0.05), betwen FPG and fructosamine 0.7953(p<.05), between two-hour plasma glucose and HbA₁0.7955-(p<.05), between 2h-PG and fructosamine 0.7770(p<.05), and between HbA₁and fructosamine 0.8142(p<.05). We found good sensitivity, specificity and positive predictive value HbA₁, and fructosamine with OGTT as a reference. After combination of FPG or 2h-PG and HbA₁especially fructosamine, sensitivity was increased. Receiver operating characteristic curves showed the cutoff point of HbA₁ 7.0 %, of fructosamine 290㎛ol/ℓ.

Conclusion : As observed in our study, HbA₁and fructosamine were highly correlated with FPG and 2h-PG. Combination of HbA₁or fructosamine and FPG or 2h-PG improve prediction over FPG or 2h-PG alone, especially fructosamine and FPG or 2h-PG combination. We conclude that mearurement of HbA₁c or fructosamine may be a useful diagnostic test for diabetes.