Comparison of the Characteristics of Patients with diabetes as Diagnosed Using Three Different Tests

ABSTRACT

BACKGROUND: Diabetes diagnosis can be made using different laboratory tests, including the fasting plasma glucose (FPG) test, 75-g 2-h oral glucose tolerance test (2-h OGTT), and hemoglobin A1c (HbA1c) test; however, these tests have different meanings. This study aimed at comparing patient characteristics based on the diagnosis using each of these 3 tests. METHODS: A total of 750 adults suspected of having diabetes and aged > or =18 years underwent the following tests on the same day FPG, 2-h OGTT, HbA1c, insulin, general chemistry, and routine urinalysis. The patients were divided into 8 groups based on the combination of positive and negative results of each of the 3 tests, and the characteristics of the patients were compared among groups. RESULTS: In the group that tested positive for all 3 tests, the FPG, 2-h OGTT, HbA1c, homeostasis model assessment for insulin resistance, alanine transaminase, triglyceride, and urine glucose positive values were higher than those of the group that tested positive using the 2-h OGTT and HbA1c test. In the group that tested positive using the 2-h OGTT, blood urea nitrogen was higher than that of the group that tested positive using the HbA1c test. CONCLUSIONS: The characteristics of the patients differed between the tests that yielded positive diagnostic results. This may be related to the fact that the 3 tests indicate different states of glucose metabolism. The results of the 3 tests were significantly different; therefore, it may be more effective to combine the results of the 3 tests to comprehensively describe patient characteristics.