Detecting Hyperglycemia Using Biomarkers Versus Continuous Glucose Monitoring

OBJECTIVE: To evaluate the concordance of glycated albumin, fructosamine, 1,5-anhydroglucitol (1,5-AG), and hemoglobin A1c (HbA1c) with continuous glucose monitor (CGM) metrics of hyperglycemia and glycemic control in a diverse population of adults with type 2 diabetes. RESEARCH DESIGN AND METHODS: This was a pooled cross-sectional analysis of 552 adults, ages 30-97 years old, with diabetes. Participants wore a CGM for up to 2 weeks, and we evaluated the agreement between blood biomarkers (glycated albumin, fructosamine, and 1,5-AG) with CGM-defined metrics of hyperglycemia and glycemic control. RESULTS: Of the 552 participants (mean age 74 years, 53% women, 36% Black), the median of mean CGM glucose was 132 mg/dL, and participants spent on average 84% of their time in range (70-180 mg/dL). CGM mean glucose was strongly related to HbA1c (r = 0.72), glycated albumin (r = 0.64), and fructosamine (r = 0.64) but weakly related to 1,5-AG (r = 0.46). Results were similar for time above range (>180 mg/dL). Glycated albumin and fructosamine performed similarly to HbA1c in the detection of target time in and above range (c-statistics ranged from 0.85 to 0.94). CONCLUSIONS: Glycated albumin and fructosamine had similar associations with CGM-defined metrics of hyperglycemia compared with HbA1c. These three biomarkers performed similarly in the detection of time above range and in range. Our results provide evidence for the utility of glycated albumin and fructosamine as alternate measures of hyperglycemia.