Continuous Glucose Monitoring Trends Among Ethnically Diverse People with Type 2 Diabetes

Background: Ethnic background and social determinants of health influence glycemic management and type 2 diabetes (T2D) outcomes, with inequities in risk and complications across diverse populations, even at similar body mass index. Hemoglobin A1c, the standard glycemic biomarker, may perform differently across ethnic groups and does not fully capture glucose variability, highlighting the need for alternative metrics. Intermittently scanned continuous glucose monitoring (CGM) offers a more granular assessment, but ethnic differences in CGM-derived glycemic patterns remain insufficiently characterized.

Objective

To determine how self-monitored glucose profiles vary according to ethnicity among adults with T2D using CGM at Toronto General Hospital, University Health Network. Methods: This single-centre observational study included adults (≥18 years) with T2D using a Freestyle Libre CGM and at least 2 consecutive weeks of usable sensor data, excluding individuals receiving high-dose oral or intravenous corticosteroids during the observation window or with insufficient CGM wear time. Ethnicity groupings were adapted from Statistics Canada and consolidated into six categories; when self-reported ethnicity was missing, non-English language was used as a proxy. Linear mixed models with random effects and splines will evaluate interactions between ethnicity and diurnal glucose patterns, adjusting for demographics, device type, and medications, using time in range, hypoglycemia, hyperglycemia, and postprandial changes as outcomes. Results: The final cohort includes 111 individuals: East Asian (n=20), South Asian (n=16), Southeast Asian (n=14), Middle Eastern and North African (n=16), White (n=30), and Other (n=15). Preliminary findings suggest higher CGM time in range among South Asian, East Asian, and Other participants, potentially implicating underlying differences in insulin sensitivity and socioeconomic context.

Conclusion

Ethnicity may influence CGM-derived glucose patterns among people with T2D. Characterizing these differences may inform more equitable, culturally sensitive diabetes care and guide interpretation of CGM metrics across diverse populations.