Effectiveness of Continuous Glucose Monitoring in Non-Intensively Managed Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Abstract

Background: The effectiveness of continuous glucose monitoring (CGM) in adults with type 2 diabetes (T2D) not receiving intensive insulin therapy remains incompletely established, particularly regarding glycemic metrics beyond glycated hemoglobin (HbA1c).

Methods: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating real-time CGM (rtCGM) or intermittently scanned CGM (isCGM) in adults with T2D managed with non-intensive insulin regimens or non-insulin therapies. Databases were searched from inception to February 2026. Primary outcomes included HbA1c, mean glucose concentration, time in range (%TIR), time above range (%TAR), time below range (%TBR), body mass index (BMI), and patient-reported outcomes. Random-effects meta-analyses were performed using Stata 17. Risk of bias was assessed using the Cochrane Risk-of-Bias tool, version 2, and certainty of evidence was evaluated using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Results: Twenty-five RCTs were included. Continuous glucose monitoring significantly reduced HbA1c (mean difference [MD] -0.34, 95% confidence interval [CI], -0.46 to -0.23), mean glucose concentration (MD -13.97 mg/dL, 95% CI, -23.13 to -4.81), and %TAR (MD -6.75%, 95% CI, -10.81 to -2.70), while significantly increasing %TIR (MD +7.85%, 95% CI, 4.32-11.38). No significant effects were observed for BMI (MD -0.16 kg/m², 95% CI, -0.45 to 0.12) or %TBR (MD -0.11%, 95% CI, -0.31 to 0.08). Benefits were generally more pronounced in non-insulin-treated populations. Patient-reported outcomes were heterogeneous but suggested improved treatment satisfaction and glucose-monitoring experience with CGM. Certainty of evidence was moderate across outcomes.

Conclusions: Continuous glucose monitoring probably improves glycemic control in adults with T2D not receiving intensive insulin therapy, particularly by reducing hyperglycemia and improving TIR, with limited effects on hypoglycemia or body weight.