Glucose Abnormalities Detected by Continuous Glucose Monitoring in Very Old Adults With and Without Diabetes

Abstract

OBJECTIVE To characterize the prevalence of continuous glucose monitoring (CGM)-defined glucose abnormalities in a large, community-based population of very old adults (>75 years). RESEARCH DESIGN AND METHODS A cross-sectional analysis of 1,150 older adults with and without diabetes who attended the Atherosclerosis Risk in Communities Study (2021–2022). Diabetes was based on a self-reported diagnosis of diabetes by a health care provider, use of diabetes medication, or a hemoglobin A1c (HbA1c) ≥6.5%. Prediabetes was defined as an HbA1c of 5.7% to <6.5% and normoglycemia as an HbA1c of <5.7%. We analyzed CGM metrics, including mean glucose, measures of hyperglycemia, and the coefficient of variation, by diabetes status. RESULTS Of the 1,150 participants (mean age 83 years, 59% women, 26% who are Black), 35.1% had normoglycemia, 34.5% had prediabetes, and 30.4% had diabetes. The summary 24-h ambulatory glucose profile for participants with prediabetes was very similar to those with normoglycemia. No participants with normoglycemia or prediabetes had a CGM mean glucose >140 mg/dL, while 32.7% of participants with diabetes had a CGM mean glucose >140 mg/dL. CONCLUSIONS In very old adults with normal or prediabetes HbA1c, hyperglycemia detected by CGM was rare. This suggests that HbA1c adequately captures the burden of hyperglycemia for most people in this population.