Real-world glycaemic outcomes in adult persons with type 1 diabetes using a real-time continuous glucose monitor compared to an intermittently scanned glucose monitor: A retrospective observational study from the Canadian LMC diabetes registry (REAL-CGM-T1D)

Real-time continuous glucose monitoring (rtCGM) and intermittently scanned CGM (isCGM) have both been shown to improve glycaemic outcomes in people with T1D. The aim of this study was to compare real-world glycaemic outcomes at 6-12 months in a propensity score matched cohort of CGM naive adults with T1D who initiated a rtCGM or an isCGM. Among the matched rtCGM and isCGM cohorts (n = 143/cohort), rtCGM users had a significantly greater HbA(1c) benefit compared to isCGM users (adjusted difference, -3 mmol/mol [95% CI, -5 to -1]; -0.3% [95% CI, -0.5 to -0.1]; p = 0.01). There was a significantly greater lowering of HbA(1c) for rtCGM compared to isCGM when baseline HbA(1c) was <69 mmol/mol (8.5%) (adjusted difference, -4 mmol/mol [95% CI, -7 mmol/mol to -2 mmol/mol]; -0.4% [95% CI, -0.6% to -0.2%]; p < 0.001), and in MDI users (adjusted difference, -3 mmol/mol [95% CI, -6 mmol/mol to -0 mmol/mol]; -0.3% [95% CI -0.5% to 0.0%], p = 0.04). The rtCGM cohort had significantly greater time in range (58.3 +/- 16.1% vs. 54.5 +/- 17.1%, p = 0.03), lower time below range (2.1 +/- 2.7% vs. 6.1 +/- 5.0%, p < 0.001) and lower glycaemic variability compared to the isCGM cohort. In this real-world analysis of adults with T1D, rtCGM users had a significantly greater reduction in HbA(1c) at 6-12 months compared to isCGM, and significantly greater time in range, lower time below range and lower glycaemic variability, compared to a matched cohort of isCGM users.