The following is a summary of “Effectiveness of Continuous Glucose Monitoring on Metrics of Glycemic Control in Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis of Randomized Controlled Trials,” published in the April 2024 issue of Endocrinology by Uhl, et al.

For a systematic review and meta-analysis, researchers sought to consolidate findings from randomized controlled trials (RCTs) evaluating continuous glucose monitors (CGMs) in managing adults with type 2 diabetes mellitus (T2DM), focusing on glucose control and clinical outcomes.

A comprehensive search of MEDLINE, Embase, and Cochrane databases was conducted to identify RCTs investigating the effectiveness of real-time CGM (rt-CGM) or flash CGM (FGM) in adults (≥18 years) with T2DM. Trials reporting outcomes such as hemoglobin A1c (HbA1c), time in range, time in hyperglycemia, or hypoglycemia were included. The certainty of evidence for primary outcomes was assessed using the GRADE approach.

Fourteen RCTs assessing CGM were included, encompassing 825 patients in 9 rt-CGM trials and 822 in 5 FGM trials. Moderate certainty of evidence suggested CGM use led to a modest yet statistically significant reduction in HbA1c levels by approximately 0.32%. Analyzing each device type separately revealed similar reductions in HbA1c (0.34% for rt-CGM and 0.33% for FGM), with trends favoring rt-CGM over self-monitored blood glucose for other glucose metrics.

Both rt-CGM and FGM demonstrated modest but statistically significant declines in HbA1c among individuals with T2DM, with minimal heterogeneity in results. However, the duration of included RCTs was relatively short, and few studies reported on critical clinical outcomes such as adverse events, emergency department use, or hospitalization. Longer-term studies are essential to ascertain whether short-term improvements in glucose control translate into clinically significant outcomes.

Reference: academic.oup.com/jcem/article/109/4/1119/7438972