Defining continuous glucose monitor time in range in a large community-based cohort without diabetes.

CONTEXT Continuous glucose monitor (CGM) companies are beginning to market these sensors to populations without diabetes, but the range of CGM values clinicians should expect to see for this population is unclear because there have been no large studies reporting these ranges. OBJECTIVE To report the physiological range of continuous glucose monitor (CGM) time in range values observed across glycemic status, including individuals without diabetes, to serve as a reference for clinicians. DESIGN The Framingham Heart Study, a prospective cohort study. SETTING Community-dwelling individuals. PATIENTS OR PARTICIPANTS Adults with normoglycemia (n=560), prediabetes (n=463), and diabetes (n=152). INTERVENTION We conducted a cross-sectional investigation in participants who wore a Dexcom G6 Pro CGM for ≥7 complete days. MAIN OUTCOME MEASURES CGM metrics including mean glucose and time spent in glucose ranges. RESULTS Normoglycemic participants (mean age 58.5y, 64.5% women, 93.3% non-Hispanic white) spent 87.0% time in the 70-140mg/dL CGM range, and, on average, >15min/day (1.2% time) >180mg/dL. Furthermore, normoglycemic participants spent ∼3 hours/day (12.1% time) with CGM glucose >140mg/dL. On average, participants with prediabetes and diabetes spent 77.1% and 46.2% time in 70-140mg/dL, respectively. CONCLUSIONS Our results contribute to the understanding of the physiological CGM range in >1000 participants without diabetes. These results are also important for clinicians to reference as CGM sensors become more widely accessible to people without known diabetes.