Relationship of Plasma Glucose and Hemoglobin A1c Levels Among Emergency Department Patients with Unknown Diabetes Status in Korea

ABSTRACT

PURPOSE: Diabetes is underdiagnosed. Higher-risk populations, such as emergency department (ED) patients, may provide an opportunity for identification of undiagnosed diabetes. Prior studies have indicated that hemoglobin A1c (HbA1c) is effective in the screening detection of diabetes. The objective of this study was to evaluate the correlation between random plasma glucose and HbA1c in Korean ED patients with unknown diabetes status and to determine the value of ED glucose level as a screening tool for diabetes. METHODS: This was a prospective nonconsecutive case series of adults aged > or =18-years-of-age presenting to the ED with acute illness that involved acquisition of a a plasma glucose sample for clinical management. From June 1-June 30, 2009, consenting patients with no prior history of diabetes underwent additional testing for HbA1c level. ED glucose results were stratified based on outpatient American Diabetes Association Fasting Plasma Glucose classifications. Two HbA1c cut-off points (6.1% and 6.5%) were selected as the optimum cut-offs for identifying diabetes based on International Expert Committee. RESULTS: There were 423 patients enrolled. The ED glucose levels were correlated with the HbA1c levels (r=0.488, p or =200 mg/dL, but most (90%) had an elevated HbA1c level. CONCLUSION: Based on the frequencies of elevated HbA1c levels among patients with elevated ED glucose values, a clinically relevant portion of hyperglycemic patients may have undiagnosed diabetes. ED patients with hyperglycemia may warrant referral for confirmatory diabetes testing.