Abstract MP018: Performance of 1,5-anhydroglucitol Compared to the Oral Glucose Tolerance Test and Fasting Glucose for Identification of Diabetes in the Community

Abstract

Introduction: The oral glucose tolerance test has been a long-standing gold standard for diabetes diagnosis. The oral glucose tolerance test measures glycemic response to a glucose challenge, but has fallen out of favor due to its high patient burden. There is growing interest in 1,5-anhydroglucitol (1,5-AG), a non-fasting test that does not require a carbohydrate challenge, for use in clinical practice. There is currently no consensus on clinical cut points for 1,5-AG, although low levels of 1,5-AG reflect recent (~2 week) glycemic excursions. Our objective was to evaluate the performance of 1,5-AG to identify cases of undiagnosed diabetes defined by the oral glucose tolerance test or fasting glucose in a community-based population. Methods: We included 7,754 Atherosclerosis Risk in Communities (ARIC) Study participants without diagnosed diabetes who attended visit 4 (1996-98). We calculated ROC curves, Youden’s index, sensitivity, and specificity to investigate the performance of 1,5-AG to identify cases of undiagnosed diabetes defined by an oral glucose tolerance test ≥ 200 mg/dL or fasting glucose ≥ 126 mg/dL. Results: The ROC curve of 1,5-AG compared to the oral glucose tolerance test as the gold standard was 0.658 and 1,5-AG compared to fasting glucose as the gold standard was 0.714. Youden’s index identified “optimal” 1,5-AG cut-points of 16 μg/mL and 17 μg/mL to identify diabetes defined by oral glucose tolerance test and fasting glucose, respectively. Decreasing values of 1,5-AG were more specific and less sensitive for detection of oral glucose tolerance test and fasting glucose-defined diabetes (Table). Conclusion: 1,5-AG is currently approved for clinical use but its utility is unclear. Given its low sensitivity for detection of diabetes, 1,5-AG may not be able to substitute for fasting glucose or the oral glucose tolerance test for screening of diabetes.