Fast Acting Insulin Aspart Compared with Insulin Aspart in the Medtronic 670G Hybrid Closed Loop System in Type 1 Diabetes: An Open Label Crossover Study

This is a single-center randomized open label active-controlled crossover trial comparing efficacy and safety of fast acting insulin aspart (FA) (FIASP(R)) versus insulin aspart (IAsp) (NovoLog(R)) when used in the Medtronic 670G system in auto mode in patients with type 1 diabetes. Forty patients were randomized to either IAsp or FA. Each treatment period was 7 weeks and a standardized meal test was administered 6 weeks after the start of each treatment period. The primary endpoint was postprandial glucose (PPG) increment after the meal test at 1 h. Treatment with FA using the MiniMed 670G hybrid closed loop (HCL) led to a greater reduction in 1-h postprandial glucose increase compared with treatment with IAsp during the standardized mixed meal test. Change in glucose: [estimated treatment difference (ETD +/- standard deviation [SD]); 95% confidence interval]: 70.27 (+/- 17.36) mg/dL (3.9 +/- 1.0 mmol/L) with FA versus 98.42 (+/- 17.36) mg/dL (5.5 +/- 1.0 mmol/L) with IAsp (P = 0.008). Patients spent 1.81% (P = 0.016) more time (equivalent to 26 min per day) in the 70-180 mg/dL (3.89-9.99 mmol/L) range with FA than with IAsp. The entire sample spent only 0.5% of time <54 mg/dL (<3.0 mmol/L) range. The increment in the 1 h postmeal test glucose was significantly lower with FA versus IAsp. FA in a HCL setting is safe and effective with patients spending more time in the 70-180 mg/dL (3.89-9.99 mmol/L) target range than with IAsp. Trial registration: Clinicaltrials.gov identifier: NCT03977727.