Effectiveness of continuous glucose monitoring in adults with Type 2 diabetes treated with basal insulin

Key Takeaway
In patients with T2D and poor glycemic control receiving BI without prandial insulin, CGM vs BGM monitoring showed:

• Significantly greater improvement in -8month HbA 1c level
• Increased time in target glucose range of 70–180mg/dL
• Reduction in both time spent at >250 mg/dL and mean glucose level

Why This Matters

• Glucose monitoring is critical for safe and effective management of individuals with T2D using insulin
• As the role of CGM in T2D using less-intensive insulin regimens is not well defined; present study compared CGM vs BGM monitoring in this study population.

Study Design

This Multicenter, Randomized (N = 175 [CGM Or BGM Group: 2:1]), Open - Label, Parallel - Group Trial Was Conducted At 15 Centers In The United States*

Key inclusion criteria

• Age ≥30 years
• T2D treated with 1 or 2 daily injections of long- or intermediate-acting basal insulin for ≤6 months
• HbA 1c: 7.8%–11.5%
• Self-reported BGM testing: ≥3 times per week
• Smart phone compatible with CGM device^†

^{Study outcomes}

• Primary outcome: HbA1c level at 8 months (adjusted for BL value)
• Key secondary outcomes:
  • Time in target glucose range of 70-180 mg/dL
  • Time at glucose level >250 mg/dL
  • Mean glucose level at 8 months (adjusted for BL value)

Key Result

A total of 175 participants were randomized (2:1) into CGM vs BGM group
(n = 116 vs 59; mean age = 57 years; mean BL HbA1c = 9.1%)

Primary outcome (cgm vs bgm group):

• HbA_1c level at 8 months^‡ 8.0% vs 8.4% (adjusted difference in mean change in HbA_1c level from baseline:
  • -0.4% [%95 CI: %0.8− to %0.1−; P = 0.02])

Key secondary outcomes (cgm vs bgm group):

• Time in target glucose range of 70-180 mg/dL (mean%): 59% vs 43% (adjusted mean difference: 15% [%95 CI: %8 to %23; P <0.001§])
• Time at glucose level >250 mg/dL (mean%):11% vs 27% (adjusted mean difference: −16% [%95 CI: %21− to %11−; P <0.001^¶])
• Mean glucose levels at 8 months: 179 vs 206 mg/dL (adjusted difference: 26− mg/dL [%95 CI: 41− to 12−; P <0.001])
• ADVERSE EVENTS: Severe hypoglycemic event (one in both, CGM and BGM group) and diabetic ketoacidosis (one in CGM group)
• CGM satisfaction scale: Mean score (CGM group) = 4.1/5

Limitations

• Follow-up duration was only 8 months
• Due to virtual visits -8month HbA 1c or CGM data was not available for some participants
• Limited generalizability of study findings to most routine clinical practice settings
• In one-third of the CGM group HbA1c level still remained >%8 after 8 months highlighting the need for more aggressive pharmacological management

^* Included participants not visiting an endocrinologist for diabetes and recruited participants from primary care practices.
^† For data uploading.
^‡Adjusted for BL values (mean BL HbA1c level [CGM vs BGM group] = %9.1 vs %9.0).
^§ Equivalent to 3.6 hours more per day.
^¶Equivalent to 3.8 hours less per day.
^#The study participants had greater contact with the clinic staff vs typical usual care scenario