Continuous Glucose Monitoring in Non-Insulin-Treated Type 2 Diabetes

Continuous glucose monitoring (CGM) has been shown to be beneficial in persons with type 1 diabetes and others with insulin-treated type 2 diabetes, but its role in the treatment of persons with type 2 diabetes not being treated with insulin has needed further study.

In a 26-week trial conducted at 22 primary care practices in the United States, we randomly assigned adults with type 2 diabetes who were not using insulin to either CGM or routine care (control). The primary outcome was the glycated hemoglobin level at 26 weeks. Key CGM-measured secondary outcomes were tested hierarchically to control the type I error rate.

A total of 145 participants were assigned to the CGM group, and 138 to the routine-care group. Participants ranged in age from 21 to 84 years. The mean (±SD) glycated hemoglobin level decreased from 8.8±1.3% at baseline to 7.2±1.1% at 26 weeks in the CGM group and from 8.7±1.2% to 8.0±1.4% in the routine-care group (adjusted mean difference, -0.9 percentage points; 95% confidence interval [CI], -1.1 to -0.6; P<0.001). The mean percentage of time that the CGM-measured glucose level was in the glucose-level range of 70 to 180 mg per deciliter was 21 percentage points higher (95% CI, 16 to 26) with CGM than with routine care (P<0.001). The between-group difference in the percentage of time that the glucose level was below 54 mg per deciliter was -0.17 percentage points (95% CI, -0.27 to -0.11; P<0.001 for noninferiority); the difference in the percentage of time that the glucose level was below 70 mg per deciliter was -0.20 percentage points (95% CI, -0.43 to -0.09; P<0.001 for noninferiority; P = 0.004 for superiority). No severe hypoglycemia events were reported.

Among adults with type 2 diabetes that was not being treated with insulin and was being managed in a primary care setting, the use of CGM led to a greater reduction in the glycated hemoglobin level and to a lower risk of hyperglycemia than routine care. (Funded by Dexcom; CONNECT ClinicalTrials.gov number, NCT06601166.).