Glycemic Improvement Using Continuous Glucose Monitoring by Baseline Time in Range: Subgroup Analyses from the DIAMOND Type 1 Diabetes Study

The DIAMOND study demonstrated that real-time continuous glucose monitors (rtCGMs) improve glycemia for adults with type 1 diabetes using multiple daily injections. This analysis explores the relationship between baseline time in range (TIR) and improvement in TIR using rtCGMs or self-monitoring of blood glucose (SMBG). Baseline TIR was divided into three categories: <40% (9.6 h per day), <50% (12 h per day), and <60% (14.4 h per day). Compared with SMBG, use of rtCGMs increased mean TIR by an additional 16 min per day for participants with a baseline TIR <40%, 77 min per day for baseline TIR <50%, and 88 min per day for baseline TIR <60%. A greater percentage of participants increased TIR by >4 h per day using rtCGMs within the three baseline TIR groups. For participants with a baseline TIR <50%, 29% of rtCGM users improved their TIR by >4 h per day compared with no SMBG users ( P  < 0.001). Similar trends were found for improvement in mean glucose and time spent in hyper- and hypoglycemic ranges.