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

Diabetes Technol Ther. 2021 Mar;23(3):230-233. doi: 10.1089/dia.2020.0471. Epub 2020 Oct 20.


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.

Trial registration: NCT02282397.

Keywords: Continuous glucose monitoring; Glycemic control; Time in range; Type 1 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Glucose Self-Monitoring
  • Blood Glucose*
  • Diabetes Mellitus, Type 1* / drug therapy
  • Glycated Hemoglobin A / analysis
  • Humans
  • Hypoglycemic Agents / therapeutic use


  • Blood Glucose
  • Glycated Hemoglobin A
  • Hypoglycemic Agents

Associated data