Continuous glucose monitoring (CGM) provides important information to improve glycemic targets in people with diabetes. We performed a meta-analysis of randomized controlled trials (RCTs) comparing CGM with usual care on glycemic control in both type 1 and type 2 diabetes.
We conducted an electronic search until June 2019 to identify RCTs assessing changes in HbA1c, time in target range (TIR), time below range (TBR), time above range (TAR) and glucose variability expressed as coefficient of variation (CV). We used a random-effects model to calculate the weighted mean difference (WMD) with the 95% CI.
We identified 15 RCTs, lasting 12–36 weeks, with 2,461 patients. Compared with the usual care (overall data), CGM was associated with reduction in HbA1c (WMD = −0.17%, 95% CI −0.29 to −0.06, I2 = 96.2%), increase in TIR (WMD = 70.74 min, 95% CI 46.73 to 94.76, I2 = 66.3%), and lower TAR, TBR and CV, with heterogeneity among studies. In pre-planned subgroup analysis, intermittent glucose monitoring was similar to control strategy for HbA1c , with less time spent in both level 1 hypoglycemia (<70 mg/dL, WMD = -56.26, 95% CI -88.91 to -23.60, I2 = 93.7%) and level 2 hypoglycemia (<54 mg/dL, WMD = -26.23, 95% CI -49.07 to -3.40, I2 = 86.8%), and lower CV (WMD = -3.86%, 95% CI -5.15 to -2.57, I2 = 78.1%).
CGM improves glycemic control by expanding TIR and decreasing TBR, TAR and glucose variability in both type 1 and 2 diabetes.