Real-time and intermittently scanned CGM associated with improved glycemic control in type 2 diabetes

A meta-analysis of 12 trials found that continuous glucose monitoring (CGM) resulted in an average difference in HbA1c of −0.31% versus self-monitoring, with a trend toward a larger effect with real-time monitoring.

Continuous glucose monitoring (CGM) is associated with improved glycemic control in adults with type 2 diabetes compared with self-monitoring of blood glucose, a recent systematic review and meta-analysis found.

A total of 12 open-label randomized controlled trials published between 2008 and 2023 were included in the analysis. Eight trials compared real-time CGM (rtCGM) with self-monitoring, and four trials compared intermittently scanned CGM (isCGM) with self-monitoring. Of 1,248 participants, 43% were female and average patient age was 58.9 years. HbA1c level at baseline ranged from a mean of 7.83% to 9.27%. Findings were published by Diabetologia on February 16.

Analyses showed that CGM use resulted in an average difference in HbA1c of −0.31% (P<0.00001). Results were similar in patients using insulin with or without oral agents and those using oral agents only. Similar results were also seen in older and younger individuals and among patients with higher or lower HbA1c levels at baseline. rtCGM trended toward a larger effect than isCGM (mean difference, −0.36% vs. −0.16%). In addition, CGM was associated with an increase in time in range (mean change, 6.36% P=0.001) and a decrease in time below range (mean change, −0.66%; P=0.02). CGM use was also linked with a decrease in time above range (mean change, −5.86%; P=0.02) and glycemic variability (mean change, −1.47%; P=0.05). One or more cases of severe hypoglycemia and macrovascular complications were reported in three studies.

"Outcome data on incident severe hypoglycemia and incident microvascular and macrovascular complications were scarce," the authors cautioned. An additional limitation to the analysis is that researchers did not include quality of life as an outcome. The duration of included studies was relatively short, with a maximum of 52 weeks.

"Future studies are needed to compare the effect on glycemic control of rtCGM to isCGM and assess the effect of CGM use on incident micro- and macrovascular complications," the authors concluded.