Use of factory calibrated real-time continuous glucose monitoring improves time in target and HbA1c in a multiethnic cohort of adolescents and young adults with type 1 diabetes: the MILLENNIALS Study
Research Design and Methods: We conducted a randomized crossover trial in young people with type 1 diabetes (16 – 24 years old), comparing the Dexcom G6 CGM system and self-monitoring of blood glucose (SMBG). Participants were assigned to the interventions in random order during two 8-week study periods. During SMBG, blinded CGM was worn by each participant for 10 days at the start, week-4 and week-7 of the control period. HbA1c measurements were drawn after enrolment, before and after each treatment period. The primary outcome was time in range 70–180mg/dl.
Results: Time in range was significantly higher during CGM compared to control [35.7±13.5% vs. 24.6±9.3%, mean difference 11.1% (95% CI 7.0 to 15.2, p<0.001)]. CGM use reduced mean sensor glucose [219.7±37.6mg/dl vs. 251.9±36.3mg/dl, mean difference -32.2mg/dl (95% CI -44.5 to -20.0, p<0.001)] and time above range [61.7±15.1% vs. 73.6±10.4%, mean difference 11.9% (95% CI -16.4 to -7.4, p<0.001)]. HbA1c level was reduced by 0.76% (95% CI -1.1 to -0.4) [-8.5mmol/mol (95% CI -12.4 to -4.6, p<0.001)]. Times spent below range (<70mg/dl and <54mg/dl) were low and comparable during both study periods. Sensor wear was 84% during the CGM period.
Conclusion: CGM use in young people with type 1 diabetes improves time in target and HbA1c levels compared to SMBG.